Varanasi, India
Varanasi, India

Banaras Hindu University ) is a public central university located in Varanasi, Uttar Pradesh. Established in 1916 by Pandit Madan Mohan Malviya, BHU is one of the largest residential universities in Asia, with over 20,000 students.The university's main campus spread over 1,300 acres was built on land donated by the Kashi Naresh, the hereditary ruler of Banaras . The Rajiv Gandhi South Campus, spread over 2,700 acres , hosts the Krishi Vigyan Kendra and is located in Barkachha in Mirzapur district, about 60 km from Banaras. The University is also planning to set up a campus in Bihar.BHU is organised into 4 institutes and 14 faculties and more than 140 departments. Total student enrolment at the university exceeds 20,000, and includes students from over 34 nations. It has over 60 hostels for resident students. Several of its colleges, including engineering , science, linguistics, journalism & mass communication, performing arts, law, agriculture , medicine and Institute of Environment And Sustainable Development , are ranked among the best in India. The university is well known for hosting an IIT. The university's engineering institute was designated an IIT in June 2012. Wikipedia.

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Kiran A.M.,University College Cork | O'Mahony J.J.,University College Cork | Sanjeev K.,Banaras Hindu University | Baranov P.V.,University College Cork
Nucleic Acids Research | Year: 2013

DARNED (DAtabase of RNa EDiting, available at is a centralized repository of reference genome coordinates corresponding to RNA nucleotides having altered templated identities in the process of RNA editing. The data in DARNED are derived from published datasets of RNA editing events. RNA editing instances have been identified with various methods, such as bioinformatics screenings, deep sequencing and/or biochemical techniques. Here we report our current progress in the development and expansion of the DARNED. In addition to novel database features the DARNED update describes inclusion of Drosophila melano-gaster and Mus musculus RNA editing events and the launch of a community-based annotation in the RNA WikiProject. © The Author(s) 2012.

Garg P.,Banaras Hindu University | Mishra D.K.,Bhabha Atomic Research Center | Netrakanti P.K.,Bhabha Atomic Research Center | Mohanty B.,National Institute of Science Education and Research | And 4 more authors.
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2013

Net-baryon, net-charge and net-strangeness number fluctuations in high energy heavy-ion collisions are discussed within the framework of a hadron resonance gas (HRG) model. Ratios of the conserved number susceptibilities calculated in HRG are being compared to the corresponding experimental measurements to extract information about the freeze-out condition and the phase structure of systems with strong interactions. We emphasize the importance of considering the actual experimental acceptances in terms of kinematics (pseudorapidity (η) and transverse momentum (pT)), the detected charge state, effect of collective motion of particles in the system and the resonance decay contributions before comparisons are made to the theoretical calculations. In this work, based on HRG model, we report that the net-baryon number fluctuations are least affected by experimental acceptances compared to the net-charge and net-strangeness number fluctuations. © 2013 Elsevier B.V.

Gupta P.K.,Banaras Hindu University | Singh M.,Dehradun Institute of Technology
Computers and Mathematics with Applications | Year: 2011

This article presents the approximate analytical solutions to solve the nonlinear FornbergWhitham equation with fractional time derivative. By using initial values, the explicit solutions of the equations are solved by using a reliable algorithm like homotopy perturbation method. The fractional derivatives are taken in the Caputo sense. Numerical results show that the HPM is easy to implement and accurate when applied to time-fractional PDEs. © 2010 Elsevier Ltd. All rights reserved.

Kharwar R.N.,Banaras Hindu University | Mishra A.,Banaras Hindu University | Gond S.K.,Banaras Hindu University | Stierle A.,University of Montana | Stierle D.,University of Montana
Natural Product Reports | Year: 2011

This is a review of anticancer agents isolated from endophytic fungi from 1990-2010. Endophytic fungi are defined as fungi that live asymptomatically within the tissues of higher plants. The designation 'anticancer' is based on the assessment of the authors of the paper of the cytotoxicity of each compound against specific cancer cell lines. Many of the compounds reported here were isolated exclusively from endophytes in culture, while other compounds had been previously reported as chemical constituents of higher plants. The uniqueness of the endophytic community of fungi is stressed as a promising source of novel compounds with anticancer activity, or as an alternative source of compounds originally isolated from higher plants. Endophytes represent a dependable source of specific secondary metabolites, and can be manipulated both physicochemically and genetically to increase yields of desired metabolites and to produce novel analogues of active metabolites. © 2011 The Royal Society of Chemistry.

Muthu M.S.,Banaras Hindu University | Feng S.-S.,National University of Singapore
Expert Opinion on Drug Delivery | Year: 2013

Liposomes are one of the effective drug delivery systems that are developed based on the nanotechnology concept. Liposomal formulation is the first nanomedicine approved by the US FDA for clinical application. Recently, the marketed liposomes and stealth liposomes have made impact for cancer therapy. In addition, a few receptor-targeted liposome products have been in different phases of clinical trials, which are yet to be marketed. In the present editorial, the advantages of vitamin E TPGS-coated liposomes over the currently available PEG-coated liposomes will be described and their great potentials for nanotheranostics for cancer imaging and therapy will be covered. © 2013 Informa UK, Ltd.

Muthu M.S.,National University of Singapore | Muthu M.S.,Banaras Hindu University | Leong D.T.,National University of Singapore | Mei L.,Tsinghua University | Feng S.-S.,National University of Singapore
Theranostics | Year: 2014

Nanotheranostics is to apply and further develop nanomedicine strategies for advanced theranostics. This review summarizes the various nanocarriers developed so far in the literature for nanotheranostics, which include polymer conjugations, dendrimers, micelles, liposomes, metal and inorganic nanoparticles, carbon nanotubes, and nanoparticles of biodegradable polymers for sustained, controlled and targeted co-delivery of diagnostic and therapeutic agents for better theranostic effects with fewer side effects. The theranostic nanomedicine can achieve systemic circulation, evade host defenses and deliver the drug and diagnostic agents at the targeted site to diagnose and treat the disease at cellular and molecular level. The therapeutic and diagnostic agents are formulated in nanomedicine as a single theranostic platform, which can then be further conjugated to biological ligand for targeting. Nanotheranostics can also promote stimuli- responsive release, synergetic and combinatory therapy, siRNA co-delivery, multimodality therapies, oral delivery, delivery across the blood-brain barrier as well as escape from intracellular autophagy. The fruition of nanotheranostics will be able to provide personalized therapy with bright prognosis, which makes even the fatal diseases curable or at least treatable at the earliest stage. © Ivyspring International Publisher.

Koiri R.K.,Dr Hari Singh Gour University | Trigun S.K.,Banaras Hindu University | Mishra L.,Banaras Hindu University
Biochimie | Year: 2015

There is a general agreement that most of the cancer cells switch over to aerobic glycolysis (Warburg effect) and upregulate antioxidant enzymes to prevent oxidative stress induced apoptosis. Thus, there is an evolving view to target these metabolic alterations by novel anticancer agents to restrict tumor progression in vivo. Previously we have reported that when a non toxic dose (10 mg/kg bw i.p.) of a novel anticancer ruthenium(II)-complex containing 4-carboxy N-ethylbenzamide; Ru(II)-CNEB, was administered to the Dalton's lymphoma (DL) bearing mice, it regressed DL growth by inducing apoptosis in the DL cells. It also inactivated M4-LDH (M4-lactate dehydrogenase), an enzyme that drives anaerobic glycolysis in the tumor cells. In the present study we have investigated whether this compound is able to modulate regulation of glycolytic inhibition-apoptosis pathway in the DL cells in vivo. We observed that Ru(II)-CNEB could decline expression of the inducible form of 6-phosphofructo-2-kinase (iPFK2: PFKFB3), the master regulator of glycolysis in the DL cells. The complex also activated superoxide dismutase (the H2O2 producing enzyme) but declined the levels of catalase and glutathione peroxidase (the two H2O2 degrading enzymes) to impose oxidative stress in the DL cells. This was consistent with the enhanced p53 level, decline in Bcl2/Bax ratio and activation of caspase 9 in those DL cells. The findings suggest that Ru(II)-CNEB is able to activate oxidative stress-apoptosis pathway via p53 (a tumor supressor protein) mediated repression of iPFK2, a key glycolytic regulator, in the DL cells in vivo. © 2015 Elsevier B.V. and Société franc¸aise de biochimie et biologie Moléculaire (SFBBM). All rights reserved.

Singh C.,Banaras Hindu University
Solid State Nuclear Magnetic Resonance | Year: 2013

Solid-state nuclear magnetic resonance (SSNMR) spectroscopy is increasingly becoming a popular technique to probe micro-structural details of biomaterial such as bone with pico-meter resolution. Due to high- resolution structural details probed by SSNMR methods, handling of bone samples and experimental protocol are very crucial aspects of study. We present here first report of the effect of various experimental protocols and handling methods of bone samples on measured SSNMR parameters. Various popular SSNMR experiments were performed on intact cortical bone sample collected from fresh animal, immediately after removal from animal systems, and results were compared with bone samples preserved in different conditions. We find that the best experimental conditions for SSNMR parameters of bones correspond to preservation at -20 C and in 70% ethanol solution. Various other SSNMR parameters were compared corresponding to different experimental conditions. Our study has helped in finding best experimental protocol for SSNMR studies of bone. This study will be of further help in the application of SSNMR studies on large bone disease related animal model systems for statistically significant results. © 2013 Elsevier Inc.

Muthu M.S.,National University of Singapore | Muthu M.S.,Banaras Hindu University | Kulkarni S.A.,National University of Singapore | Raju A.,National University of Singapore | Feng S.-S.,National University of Singapore
Biomaterials | Year: 2012

The aim of this work was to develop a new type of d-alpha-tocopheryl polyethylene glycol 1000 succinate mono-ester (TPGS) coated multi-functional (theranostic) liposomes, which contain both docetaxel and quantum dots (QDs) for cancer imaging and therapy. Non-targeting and folate receptor targeting TPGS coated theranostic liposomes were prepared by the solvent injection method and characterized for their particle size, polydispersity, zeta potential, surface chemistry and drug encapsulation efficiency. MCF-7 breast cancer cells of folate receptor overexpression were employed as an in vitro model to assess cellular uptake and cytotoxicity of the drug and QDs loaded liposomes. The mean particle size of the non-targeting and the targeting liposomes was found to be 202 and 210 nm, respectively. High resolution field emission transmission electron microscopy (FETEM) confirmed the presence of quantum dots in the peripheral hydrophobic membranes of the liposomes. The qualitative internalization of multi-functional liposomes by MCF-7 cells was visualized by confocal laser scanning microscopy (CLSM). The IC50 value, which is the drug concentration needed to kill 50% cells in a designated time period, was found to be 9.54 ± 0.76, 1.56 ± 0.19 and 0.23 ± 0.05 μg/ml for the commercial Taxotere ®, non-targeting and targeting liposomes, respectively after 24 h culture with MCF-7 cells. The targeting multi-functional liposomes showed greater efficacy than the non-targeting liposomes and thus great potential to improve the cancer imaging and therapy. © 2012 Elsevier Ltd.

Agency: Cordis | Branch: FP7 | Program: CP-FP-SICA | Phase: SSH-2010-4.2-1 | Award Amount: 2.91M | Year: 2011

In the post-Cold War world is witnessing the emergence of new forms of intra-state conflicts accompanied by a weakening of the nation-states traditional means of dealing with these. There is a visible need for substantial revision in conventional approaches and strategies aimed at transforming such conflicts. Conflict resolution agendas have in the last two decades for the most part been shaped by the political objective of bringing political and economic liberalization in the name of promoting of human rights, rule of law and democracy. However, these strategies often fail to take into consideration the complex social and cultural contexts of the local level. There is a gap in knowledge about the impact that governance agendas have on local conflict dynamics, especially in the cases where identity mobilisation is a prominent factor in the conflict. This project will analyse the premises and operation of governance initiatives in conflict transformation processes through a combination of fieldwork, qualitative analysis and theory development. It will carry out case studies encompassing recent governance practices in Bihar, Bosnia, Cyprus, Georgia, North East India and Kashmir. The project will be conducted in collaboration between Indian and European research teams. The project will review and critique current approaches to conflict resolution in an attempt to revise and improve both the theoretical and operational sides of conflict resolution and peace building. It will facilitate a reciprocal learning process between appropriate parties of the European Union and Indian actors and policy makers in order to enhance the perspectives and methods of both. The project will result in a variety of outputs, including a report series addressed to both EU and Indian policymakers, a variety of local level consultations, two large international conferences, a series of scholarly articles and working papers for the research community, and a scholarly book. A high-profile web forum will be developed to enhance communication between researchers, policymakers, practitioners and the wider public.

News Article | December 16, 2016

BENGALURU, INDIA—India is home to a flourishing community of predatory journals: outlets that masquerade as legitimate scientific publications but publish papers with little or no peer review while charging authors hefty fees. Many observers assumed that such bottom feeders were mostly attracting papers of dubious scientific value, if not plagiarized or fraudulent reports, from institutions in academia’s outer orbits. But a new analysis has found that many of the weak papers in predatory journals are coming from top-flight Indian research institutions. The finding has turned the spotlight on an academic culture in India that tends to prize quantity of publications over quality when evaluating researchers. This is an especially big problem in the life sciences, and it will take time to fix, says K. Vijayraghavan, the secretary of India’s Department of Biotechnology (DBT) in New Delhi, which funded some of the research that ended up in predatory journals. “Biology, in general, has become ghastly, in that people are chasing the metrics,” he says. “If you chase these surrogate markers of success instead of science, we have a problem.” Recent revelations have pointed to a symbiotic relationship in India between questionable publishers and mediocre researchers. In 2013, a investigation traced the publishers and editors of scores of predatory journals to India. And last year, a team reported in that of a selection of 262 authors published in predatory journals, 35% were Indian. Delving deeper, Gopalkrishnan Saroja Seethapathy, a graduate student in pharmaceutical chemistry at the University of Oslo, and colleagues randomly chose 3300 papers by Indian first authors from 350 journals flagged as predatory by Jeffrey Beall, a library scientist at the University of Colorado in Denver. In an analysis in the 9 December issue of , they report that more than half the papers were by authors from government-run and private colleges: hotbeds of mediocre research. But about 11% of papers, they found, were from India’s premier government research bodies, including dozens of publications from institutions belonging to the Indian Council of Agricultural Research (ICAR), the Council of Scientific and Industrial Research, and the Indian Institutes of Technology. “Funding agencies have to be careful about where papers are published,” says Subhash Chandra Lakhotia, a cytogeneticist at Banaras Hindu University in Varanasi, which is a source of some papers in predatory journals. “They have to take their jobs seriously and find time to read papers, instead of simply going by the number of papers published.” Some say that the root of the problem is, paradoxically, recent government attempts to improve Indian research output. India’s University Grants Commission (UGC), a body charged with setting educational standards, in 2010 made it mandatory for all faculty in higher educational institutions to publish papers in order to be evaluated favorably. Pushkar, the director of the International Centre Goa who goes by one name, says this move pushed teaching faculty with no expertise in research towards predatory journals. “The research component in the performance metrics for faculty in teaching-focused institutions is the reason why predatory journals attract so many submissions,” he told . When concerns were raised about the proliferation of papers published in poor-quality journals, UGC announced that it would change its performance metrics and compile a list of peer-reviewed journals in which researchers would need to publish. That’s not the best solution, Vijayraghavan argues. “The fundamental problem is an ecosystem that values where you publish and how many papers you publish rather than what you publish. That needs to be changed,” he says. To bring about change, DBT launched an open-access policy in 2014, which requires all published papers to be uploaded to a central repository, so that they can be evaluated according to their merit. The department also plans to launch a preprint repository, along the lines of arXiv, to encourage sharing of research prior to publication. The idea is to galvanize a culture of evaluating research by reading publications rather than focusing on numbers of papers published or impact factors. “This will pull the carpet from under the feet of predatory publishers,” Vijayraghavan says. Some scientists feel that the predatory publishing scourge is overblown. ICAR Director General Trilochan Mohapatra argues that many publications classified as predatory could merely be little-known journals that charge publication fees. “There are many flaws with the paper,” he says. “We will internally analyze this issue, see if a real problem exists at ICAR, and come out with our own study.”

Singh V.P.,Banaras Hindu University | Singh P.,Banaras Hindu University | Singh A.K.,North West University South Africa
Inorganica Chimica Acta | Year: 2011

Cobalt(II), nickel(II), copper(II) and zinc(II) complexes with 2-acetylthiophene benzoylhydrazone have been synthesized and characterized by elemental analyses, magnetic susceptibility measurements, electronic, IR, NMR and ESR spectral techniques. The molecular structures of ligand and its copper(II) complex have been determined by single crystal X-ray diffraction technique. The Cu(II) complex possesses a CuN2O2 chromophore with a considerable delocalization of charge. The structure of the complex is stabilized by intermolecular π-π stacking and C-H⋯π interactions. Hatbh acts as a monobasic bidentate ligand in all the complexes bonding through a deprotonated C-O- and >CN groups. Electronic spectral studies indicate an octahedral geometry for the Ni(II) complex while square planar geometry for the Co(II) and Cu(II) complexes. ESR spectrum of the Cu(II) complex exhibits a square planar geometry in solid and in DMSO solution. The trend g|| > g⊥ > 2.0023 indicates the presence of an unpaired electron in the dx2-y2 orbital of Cu(II). The electro-chemical study of Cu(II) complex reveals a metal based reversible redox behavior. The Ni(II) complex shows exothermic multi-step decomposition pattern of the bonded ligand. The ligand and its most of the metal complexes show appreciable corrosion inhibition properties for mild steel in 1 M HCl medium. [Co(atbh)2] complex exhibited the greatest impact on corrosion inhibition among the other compounds. © 2011 Elsevier B.V. All rights reserved.

Dumka U.C.,Aryabhatta Research Institute of Observational science | Kaskaoutis D.G.,Shiv Nadar University | Srivastava M.K.,Banaras Hindu University | Devara P.C.S.,Amity University
Atmospheric Chemistry and Physics | Year: 2015

Light scattering and absorption properties of atmospheric aerosols are of vital importance for evaluating their types, sources and radiative forcing. This is of particular interest over the Gangetic-Himalayan (GH) region due to uplift of aerosol from the plains to the Himalayan range, causing serious effects on atmospheric heating, glaciology and monsoon circulation. In this respect, the Ganges Valley Aerosol Experiment (GVAX) was initiated in Nainital from June 2011 to March 2012 with the aim of examining the aerosol properties, source regions, uplift mechanisms and aerosol-radiation-cloud interactions. The present study examines the temporal (diurnal, monthly, seasonal) evolution of scattering (σsp) and absorption (σap) coefficients, their wavelength dependence, and the role of the Indo-Gangetic plains (IGP), boundary-layer dynamics (BLD) and long-range transport (LRT) in aerosol evolution via the Atmospheric Radiation Measurement Mobile Facility. The analysis is separated for particles 10μm and <1 μm in diameter in order to examine the influence of particle size on optical properties. The σsp and σap exhibit a pronounced seasonal variation between the monsoon low and post-monsoon (November) high, while the scattering wavelength exponent exhibits higher values during the monsoon, in contrast to the absorption Ångström exponent which maximizes in December-March. The elevated-background measuring site provides the advantage of examining the LRT of natural and anthropogenic aerosols from the IGP and southwest Asia and the role of BLD in the aerosol lifting processes. The results reveal higher aerosol concentrations at noontime along with an increase in mixing height, suggesting influence from IGP. The locally emitted aerosols present higher wavelength dependence of the absorption in October-March compared to the rather well-mixed and aged transported aerosols. Monsoon rainfall and seasonally changing air masses contribute to the alteration of the extensive and intensive aerosol properties.

Singh P.,Banaras Hindu University | Singh A.K.,North West University South Africa | Singh V.P.,Banaras Hindu University
Polyhedron | Year: 2013

A series of metal complexes of Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) with o-hydroxyacetophenone-2-thiophenoyl hydrazone (Hhath) have been synthesized. The metal complexes were characterized with the help of elemental analyses, magnetic susceptibility measurements, electronic, IR, NMR and ESR spectral techniques. The structures of Hhath ligand and its Mn(II) complex were determined by single crystal X-ray diffraction studies. Hhath displays E configuration about the >CN- bond. The molecular structure of ligand is stabilized by inter- and intra-molecular H-bonding whereas, [Mn(hath) 2] complex is stabilized by π-π and C-Hâ̄π interactions. In all the complexes, ligand behaves as mono-anionic tridentate and binds to the metal ions via deprotonated phenolate-oxygen, carbonyl-oxygen and azomethine-nitrogen. Magnetic moments and electronic spectral studies suggest an octahedral geometry around metal ion in all the complexes. Frozen solution ESR spectra of Cu(II) complex in DMSO gives axial signal and suggests 2B1g as the ground state. The ligand and its metal complexes showed appreciable corrosion inhibition activity against corrosion of mild steel in 1 M HCl solution. The inhibition efficiency of the inhibitors was found to increase with time up to 12 h and thereafter almost constant. The metal complexes showed greater inhibition efficiency than the free ligand. © 2013 Elsevier Ltd. All rights reserved.

Hamdani M.,University Ibn Zohr | Singh R.N.,Banaras Hindu University | Chartier P.,CNRS Institute of Chemistry
International Journal of Electrochemical Science | Year: 2010

Many spinel cobaltite oxides meet the requirement for a wide range of electrochemical reactions. These materials have largely been investigated as electrocatalysts for the oxygen evolution reaction (OER) or oxygen reduction reaction (ORR). The objective of this article is to summarize the studies available in the literature on electrochemical and electrocatalytic properties of cobaltite spinel oxides towards the OER and ORR in alkaline media. The main focus of this review is on the recent investigations dealing with the performance of Co3O4and Cobased spinel oxides as the oxygen electrodes in the light of the earlier published work. © 2010 by ESG.

Shukla U.K.,Banaras Hindu University | Srivastava P.,Wadia Institute of Himalayan Geology | Singh I.B.,University of Lucknow
Geomorphology | Year: 2012

The lithofacies constitution of unconsolidated sediments exposed in Ramnagar cliff indicates sedimentation in sinuous channels, associated flood plain areas and ponds that were developed within the Ganga River valley. The Khadar surface represents a raised river valley terrace into which the main river channel along with its narrow floodplain is incised. Ramnagar cliff section has revealed a variety of deformation structures that indicate repeated tectonic activity in the area. Important tectonic features exposed by the cliff section are reverse faults, folds, cracks filled with sparry calcite and soft sediment structures indicating liquefaction of sediments affected by faulting and folding. Optically stimulated luminescence (OSL) dating of sediments and field relationships of tectonic elements indicate that the Ganga River migrated near to Varanasi 40. ka following a tectonic event in the area. Since then, it meandered freely within its valley until 7. ka when another tectonic event took place and Ramnagar cliff was raised to its present heights. The cliff surface was degraded by gulling activity for about 4000. years before it was occupied by man at around 3000. years. BP. © 2012 Elsevier B.V.

Mishra R.B.,Banaras Hindu University | Kumar S.,Banaras Hindu University | Kumar S.,M M University
Artificial Intelligence Review | Year: 2011

Semantic web reasoners and languages enable the semantic web to function. Some of the latest reasoning models developed in the last few years are: DLP, FaCT, RACER, Pellet, MSPASS, CEL, Cerebra Engine, QuOnto, KAON2, HermiT and others. Some software tools such as Protégeacute;, Jena and others also have been developed, which provide inferencing as well as ontology development and management environments. These reasoners usually differ in their inference procedures, supporting logic, completeness of reasoning, expressiveness and implementation languages. Various semantic web languages with increasing expressive power continue to be developed for describing web services. We survey the some of the more recent languages like OWL-S (Ontology Web Language-Schema), WSML (Web Service Modeling Language), SWRL (Semantic Web Rule Language) and others that have been tested in early use. We also survey semantic web reasoners and their relationship to these languages. © Springer Science+Business Media B.V. 2010.

Singh B.N.,Sowbhagya Biotech Private Ltd Cherlapally | Singh H.B.,Banaras Hindu University | Singh A.,Banaras Hindu University | Naqvi A.H.,Aligarh Muslim University | Singh B.R.,Aligarh Muslim University
Cancer and Metastasis Reviews | Year: 2014

Cancer metastasis is a multistep process in which a cancer cell spreads from the site of the primary lesion, passes through the circulatory system, and establishes a secondary tumor at a new nonadjacent organ or part. Inhibition of cancer progression by dietary phytochemicals (DPs) offers significant promise for reducing the incidence and mortality of cancer. Consumption of DPs in the diet has been linked to a decrease in the rate of metastatic cancer in a number of preclinical animal models and human epidemiological studies. DPs have been reported to modulate the numerous biological events including epigenetic events (noncoding micro-RNAs, histone modification, and DNA methylation) and multiple signaling transduction pathways (Wnt/β-catenin, Notch, Sonic hedgehog, COX-2, EGFR, MAPK-ERK, JAK-STAT, Akt/PI3K/mTOR, NF-κB, AP-1, etc.), which can play a key role in regulation of metastasis cascade. Extensive studies have also been performed to determine the molecular mechanisms underlying antimetastatic activity of DPs, with results indicating that these DPs have significant inhibitory activity at nearly every step of the metastatic cascade. DPs have anticancer effects by inducing apoptosis and by inhibiting cell growth, migration, invasion, and angiogenesis. Growing evidence has also shown that these natural agents potentiate the efficacy of chemotherapy and radiotherapy through the regulation of multiple signaling pathways. In this review, we discuss the variety of molecular mechanisms by which DPs regulate metastatic cascade and highlight the potentials of these DPs as promising therapeutic inhibitors of cancer. © 2014 Springer Science+Business Media New York.

Singh B.R.,Aligarh Muslim University | Singh B.N.,University of Kansas | Khan W.,Aligarh Muslim University | Singh H.B.,Banaras Hindu University | Naqvi A.H.,Aligarh Muslim University
Biomaterials | Year: 2012

Cadmium sulfide (CdS) quantum dots (QDs) have raised great attention because of their superior optical properties and wide utilization in biological and biomedical studies. However, little is known about the cell death mechanisms of CdS QDs in human cancer cells. This study was designed to investigate the possible mechanisms of apoptosis induced by biosurfactant stabilized CdS QDs (denoted as " bsCdS QDs" ) in human prostate cancer LNCaP cells. It was also noteworthy that apoptosis correlated with reactive oxygen species (ROS) production, mitochondrial damage, oxidative stress and chromatin condensation in a dose- and time-dependent manner. Results also showed involvement of caspases, Bcl-2 family proteins, heat shock protein 70, and a cell-cycle checkpoint protein p53 in apoptosis induction by bsCdS QDs in LNCaP cells. Moreover, pro-apoptotic protein Bax was upregulated and the anti-apoptotic proteins, survivin and NF-κB were downregulated in bsCdS QDs exposed cells. Protection of N-acetyl cysteine (NAC) against ROS clearly suggested the implication of ROS in hyper-activation of apoptosis and cell death. It is encouraging to conclude that biologically stabilized CdS QDs bear the potential of its applications in biomedicine, such as tumor therapy specifically by inducing caspase-dependent apoptotic cell death of human prostate cancer LNCaP cells. © 2012.

Singh A.K.,North West University South Africa | Singh A.K.,Banaras Hindu University
Industrial and Engineering Chemistry Research | Year: 2012

The inhibition effect of 3-(4-((Z)-indolin-3-ylideneamino)phenylimino) indolin-2-one Schiff base (PDBI) on mild steel corrosion in 1 M HCl solution was studied by using electrochemical techniques such as potentiodynamic polarization curves, weight loss, electrochemical impedance spectroscopy, and linear polarization resistance. PDBI has remarkable inhibition efficiency on the corrosion of mild steel in 1 M HCl solution. Polarization measurements indicated that PDBI acts as mixed type corrosion inhibitor. The adsorption of PDBI on the mild steel surface obeys Langmuir adsorption isotherm. These results were supplemented by atomic force microscopy and scanning electron microscopy. © 2012 American Chemical Society.

Singh A.K.,North West University South Africa | Quraishi M.A.,Banaras Hindu University
International Journal of Electrochemical Science | Year: 2012

The effect of Schiff base compounds, namely, ethylenediamine bis-isatin (EDBI), hexane 1,4-diamine bis-isatin (HDBI) and thiocarbohydrazide bis-isatin (TCBI) were investigated by gravimetric, potentiodynamic polarization, electrochemical impedance spectroscopy, atomic force microscopy and scanning electron microscopy. Although effect of molecular planarity on inhibition efficiency is observed from the results obtained between EDBI and HDBI. Adsorption of these inhibitors obeyed the Frumkin adsorption isotherm. It was found that efficiency order followed by inhibitor is TCBI>EDBI>HDBI. This fact strongly suggests that, an efficient corrosion inhibitor molecule should be large one, planar, having unoccupied d-orbital and also containing an extensive number of π-electrons. © 2012 by ESG.

Singh A.,Banaras Hindu University | Ebenso E.E.,North West University South Africa | Quraishi M.A.,Banaras Hindu University
International Journal of Electrochemical Science | Year: 2012

The stem extract of Bacopa monnieri was investigated as corrosion inhibitor of aluminium in 0.5 M NaOH solution using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) methods, and weight loss measurements. The results revealed that Bacopa monnieri stem extract was an effective inhibitor, and the inhibition efficiencies obtained from polarization and weight loss experiments were in good agreement. Using the potentiodynamic polarization technique, the extract proved to be a mixed-type inhibitor for aluminium in alkaline solution by suppressing both anodic and cathodic reactions on the metal surface. The Langmuir adsorption isotherm model fitted results obtained from the weight loss. Thermodynamic parameters such as activation energy, free energy of adsorption were calculated. © 2012 by ESG.

Parchur A.K.,Banaras Hindu University | Prasad A.I.,Bhabha Atomic Research Center | Rai S.B.,Banaras Hindu University | Ningthoujam R.S.,Bhabha Atomic Research Center
Dalton Transactions | Year: 2012

As-prepared samples of YPO 4:2Dy nanoparticles prepared by polyol route show strong blue luminescence because of strong host contribution, whereas 500 and 900 °C annealed samples show cold and warm white luminescence, respectively because of different energy transfer rates from host to Dy 3+. Li + co-doping improves luminescence intensity as well as crystallinity significantly. Interestingly, Li + ions occupy interstitial sites of lattice. These materials will be potential candidates for white light emitting diodes and near-infrared emitting phosphors. © 2012 The Royal Society of Chemistry.

Parchur A.K.,Banaras Hindu University | Prasad A.I.,Bhabha Atomic Research Center | Ansari A.A.,King Saud University | Rai S.B.,Banaras Hindu University | Ningthoujam R.S.,Bhabha Atomic Research Center
Dalton Transactions | Year: 2012

Tb 3+-doped CaMoO 4 (Tb 3+ = 1, 3, 5, 7, 10, 15 and 20 atom%) core and core-shell nanoparticles have been prepared by urea hydrolysis in ethylene glycol (EG) as capping agent as well as reaction medium at low temperature ∼150 °C. As-prepared samples were annealed at 500 and 900 °C for 4 h to eliminate unwanted hydrocarbons and/or H 2O present in the sample and to improve crystallinity. The synthesised nanophosphors show tetragonal phase structure. The crystallite size of as-prepared sample is found to be ∼18 nm. The luminescence intensity of the 5D 4 → 7F 5 transition at 547 nm of Tb 3+ is much higher than that of the 5D 4 → 7F 6 transition at 492 nm. 900 °C annealed samples show the highest luminescence intensity. The intensity ratio R (I[ 5D 4 → 7F 6]/I[ 5D 4 → 7F 5]) lies between 0.3-0.6 for as-prepared, 500 and 900 °C annealed samples. The luminescence decay of 5D 4 level under 355 nm excitation shows biexponential behaviour indicating availability of Tb 3+ ions on surface and core regions of particle; whereas, contribution of Mo-O charge transfer to lifetime is obtained under 250 nm excitation. The CIE coordinates of as-prepared, 500 and 900 °C annealed 5 atom% Tb 3+-doped CaMoO 4 samples under 250 nm excitation are (0.28, 0.32), (0.22, 0.28) and (0.25, 0.52), respectively. The dispersed particles in polar medium and its polymer film show green light emission. The luminescence intensity is improved significantly after core-shell formation due to extent of decrease of non-radiative rates arising from surface dangling bonds and capping agent. Quantum yields of as-prepared samples of 1, 5 and 7 atom% Tb 3+-doped CaMoO 4 samples are found to be 10, 3 and 2, respectively. © 2012 The Royal Society of Chemistry.

Parchur A.K.,Banaras Hindu University | Ningthoujam R.S.,Bhabha Atomic Research Center
RSC Advances | Year: 2012

The effect of Li+ co-doping on the photoluminescence properties of YPO4:Eu is discussed. Interesting behaviours, such as the presence of intermediate bands, shifting of the Eu-O charge transfer band (Eu-O CTB) to a lower wavelength, variation in intensities of magnetic (5D 0 → 7F1) and electric dipole ( 5D0 → 7F2) transitions of Eu3+ and shift of 5D0 → 7F 0 to higher energy with increasing excitation wavelengths are observed. The Eu3+ ion does not have an absorption band in the range 340-350 nm, but after excitation at these wavelengths, a broad emission band (370-570 nm), as well as sharp peaks of Eu3+, could be observed. This is due to strong energy transfer from the intermediate band of the host to the Eu3+ ion. X-ray photoelectron spectroscopy (XPS) study also confirms that intermediate band emission is not due to Eu2+ ion emission. The blue shifting of Eu-O CTB is because of the increase in the optical electronegativity of the Eu3+ ion on Li+ co-doping. The variation in intensities of the 5D0 → 7F2 and 5D0 → 7F1 dipole transitions is related to (i) overlapping interaction parameters within the ground and excited states, (ii) exchange interaction among atoms/ions and (iii) density of the incoming photons. Shift of 5D0 → 7F0 to a higher energy with increasing excitation wavelengths is because of change in the second order crystal field parameter B20 with excitation wavelength. The significant enhancement of luminescence intensity is found with Li+ co-doping due to the increase in crystallinity. © 2012 The Royal Society of Chemistry.

Khattri S.D.,Banaras Hindu University | Singh M.K.,Banaras Hindu University | Singh M.K.,Ideal Institute of Technology
Environmental Progress and Sustainable Energy | Year: 2012

Removal of dye crystal violet from wastewater by a low-cost abundantly available adsorbent was investigated. By varying the parameters such as agitation time, dye concentration, adsorbent dose, pH and temperature, potential feasibility for the removal of crystal violet by Sagaun sawdust was explored. The adsorption efficiencies were found to be pH dependent. A greater percentage of dye was removed with a decrease in the initial concentration of dye and increase in the amount of adsorbent. Characterization of the adsorbent by infrared spectroscopy was undertaken. Kinetic study showed that the adsorption of dye on sawdust was a gradual process. The equilibrium adsorption capacity of adsorbent for dye removal was measured which followed Langmuir isotherm. The dimensionless factor, R L revealed that the adsorption process is favorable in nature. © 2012 American Institute of Chemical Engineers.

Verma R.K.,Banaras Hindu University | Ila H.,New Chemistry Unit | Singh M.S.,Banaras Hindu University
Tetrahedron | Year: 2010

2-[Bis(methylthio)methylene]-1,3-indanedione has been shown to be a useful three carbon 1,3-dielectrophilic synthon for the highly efficient regiospecific synthesis of a variety of indenofused five- and six-membered heterocycles via heteroaromatic annulation. The methodology has been further elaborated to the corresponding N,S-acetals leading to amino substituted heterocycles, thus providing further point of diversity in the newly synthesized heterocyclic frameworks. Further, the facile access to cytotoxic indeno[2,1-c]quinolin-7-ones and the novel polycyclic heteroaromatics demonstrates the versatility of heteroaromatic annulation protocol via α-oxoketene-S,S-acetal in generating novel biologically important polycyclic heteroaromatics. © 2010 Elsevier Ltd. All rights reserved.

Yoo J.J.,Rice University | Yoo J.J.,KAIST | Balakrishnan K.,Rice University | Huang J.,Oak Ridge National Laboratory | And 10 more authors.
Nano Letters | Year: 2011

With the advent of atomically thin and flat layers of conducting materials such as graphene, new designs for thin film energy storage devices with good performance have become possible. Here, we report an "in-plane" fabrication approach for ultrathin supercapacitors based on electrodes comprised of pristine graphene and multilayer reduced graphene oxide. The in-plane design is straightforward to implement and exploits efficiently the surface of each graphene layer for energy storage. The open architecture and the effect of graphene edges enable even the thinnest of devices, made from as grown 1-2 graphene layers, to reach specific capacities up to 80 μFcm-2, while much higher (394 μFcm-2) specific capacities are observed multilayer reduced graphene oxide electrodes. The performances of devices with pristine as well as thicker graphene-based structures are examined using a combination of experiments and model calculations. The demonstrated all solid-state supercapacitors provide a prototype for a broad range of thin-film based energy storage devices. © 2011 American Chemical Society.

Singh B.P.,Indian Institute of Technology BHU Varanasi | Parchur A.K.,Banaras Hindu University | Ningthoujam R.S.,Bhabha Atomic Research Center | Ansari A.A.,King Saud University | And 2 more authors.
Dalton Transactions | Year: 2014

We have studied the luminescence property of CaMoO4:Eu 3+. The emission peaks at 590 (5D0→ 7F1) and 613 nm (5D0→ 7F2) for Eu3+ are observed after excitation at 266 nm (i.e. Mo-O charge transfer band). The peak intensity of the latter dominates over the former indicating an asymmetric environment of Eu 3+ in EuO8 polyhedron or parity mixing. Luminescence intensity increases significantly with co-doping of Gd3+. This is ascribed to energy transfer from Mo-O/Gd3+ to Eu3+. Luminescence intensity increases with annealing up to 900°C due to the extent of decrease of non-radiative rates. Very high asymmetric values (A 21) of 12-16 are found indicating a red emitter. As-prepared samples are dispersible in polar solvents like water, ethanol, methanol, dimethyl sulfoxide (DMSO) and ethylene glycol (EG); and among them, optimum luminescence is found in methanol. Polymer film shows red emission. The quantum yields of as-prepared 2 and 10 at% Gd3+ co-doped CaMoO4:Eu 3+ under 277 nm (UV excitation) are 21 and 80%, respectively. © 2014 The Royal Society of Chemistry.

Kumar M.D.,Institute for Resource Analysis and Policy | Scott C.A.,University of Arizona | Singh O.P.,Banaras Hindu University
Journal of Hydrology | Year: 2011

India's farm sector sustains livelihoods for hundreds of millions of rural people, but faces serious management challenges for land, water, and energy resources. Growing dependence on groundwater threatens water resources sustainability and power sector viability. Sustaining India's rising prosperity rests on managing groundwater. This study shows that raising power tariffs in the farm sector to achieve efficiency and sustainability of groundwater use is both socially and economically viable. The question is about how to introduce this shift. This paper discusses five different options for power supply, metering and energy pricing in the farm sector and the expected outcomes of implementing each vis-a-vis efficiency of groundwater and energy use, equity in access and sustainability of groundwater. It concludes that establishing an energy quota for each farm-based on sustainability considerations, and metering and charging pro rata for power used are the best options to manage groundwater and the energy economy. © 2011 Elsevier B.V.

Parchur A.K.,Banaras Hindu University | Ningthoujam R.S.,Bhabha Atomic Research Center
Dalton Transactions | Year: 2011

The nanoparticles of CaMoO 4:Eu 3+ (Eu 3+ = 0, 1, 3, 5, 7, 10 at. %) are prepared at low temperature (150 °C for 3 h) using urea hydrolysis in ethylene glycol. These are characterized by X-ray diffraction (XRD), infrared spectroscopy (IR) and transmission electron microscopy (TEM). From XRD study, it was found that the solubility limit of Eu 3+ ions at the Ca 2+ sites is up to 3 at. % and above this, phase segregation occurs. In combination with Rietveld analysis, its crystal structure was found to be tetragonal phase (space group I4 1/a (88) and Z = 4 (number of CaMoO 4 formula units per unit cell). Unit cell parameters and bond distances are calculated. The average crystallite sizes of as-prepared, 500 and 900 °C heated samples are found to be 20, 35 and 70 nm, respectively. The lattice strain is found to be 0.003-0.005. From IR study, the bands at 820 and 441 cm -1 are assigned to asymmetric stretching and bending vibrations of the MoO 4 2- tetrahedron, respectively. From TEM study, the shape of particle was found to be spherical. The high resolution TEM suggests a change in orientation of the crystal on annealing up to 900 °C. © The Royal Society of Chemistry 2011.

Maken A.,Banaras Hindu University | Maken S.,D. C. R. University of Science and Technology
Journal of Industrial and Engineering Chemistry | Year: 2012

Molar excess enthalpies (H E) of 1,4-dioxane (A)+aniline or formamide or N, N-dimethylaniline or N, N-dimethylformamide (B) mixtures have been measured at 308.15K over the entire composition range using flow isothermal micro calorimeter. The H E values for 1,4-dioxane+N, N-dimethylaniline or N, N-dimethylformamide were found to be small and positive and, these are large and negative for mixture containing aniline, whereas these change sign from negative to positive for 1,4-dioxane+formamide. The H E versus mole fraction of 1,4-dioxane (x A) plots for 1,4-dioxane (A)+aniline or N, N-dimethylaniline or N, N-dimethylformamide (B) system are symmetrical about x A=0.5 and for equimolar mixtures, H E for these system follow the sequence: aniline

Pandey D.,Banaras Hindu University | Pandey D.,SevenHills Hospital
HPB | Year: 2012

Background: The guidelines for resection of gallbladder cancer include a regional lymphadenectomy; yet it is uncommonly performed in practice and inadequately described in the literature. The present study describes the technique of a regional lymphadenectomy for gallbladder cancer, as practiced by the author. Methods/Technique: After confirming resectability, the duodenum is kocherized. The dissection starts from the posterior aspects of the duodenum and head of the pancreas and extends superiorly to the retroportal area. This is followed by dissection of the common hepatic artery and its branches, the bile duct and the anterior aspect of the portal vein until the hepatic hilum. Resection of the gallbladder with an appropriate liver resection completes the surgery. Results: This technique was used for a regional lymphadenectomy in 27 patients, of which 14 underwent radical cholecystectomy upfront, and 13 had revisional surgery for incidentally detected gallbladder cancer. The median number of lymph nodes dissected on histopathology was 8 (range 3 to 18). Eleven patients had metastatic lymph nodes on histopathological examination. There was no post-operative mortality. Two patients had a bile leak which resolved with conservative management. Conclusion: A systematic approach towards a regional lymphadenectomy ensures a consistent nodal harvest in patients undergoing radical resection for gallbladder cancer. © 2012 International Hepato-Pancreato-Biliary Association.

Mishra A.,Banaras Hindu University | Aswal V.K.,Bhabha Atomic Research Center | Maiti P.,Banaras Hindu University
Journal of Physical Chemistry B | Year: 2010

We report the step by step self-assembly from nanostructure to microstructure (bottom-up approach through X-ray diffraction (1.6 nm), small angle neutron scattering (SANS) (11.6 nm), atomic force microscopy (70 nm smaller crystallite from enlarged image and 450 nm greater crystallites), and polarizing optical microscope (2 μm)) of aliphatic polyurethanes (PU) in contrast to aromatic polyurethanes depending on hard segment content (HSC). Polyurethanes of 10 to 80% HSC have been synthesized by using appropriate amount of polyol and chain extender. The effect of self-assembled patterns on mechanical properties both in solid and liquid state has been established exhibiting structure-property relationship of supramolecular polyurethanes. The crystallinity enhances but the degradation temperature decreases with increasing HSC. The characteristic length (measure of gap between lamellar crystallites), as revealed from SANS, gradually decreases with increasing HSC suggesting compactness of the crystallites through extensive hydrogen bonding. The Youngs modulus increases with increasing HSC with a percolation threshold of hard segment (50%) while the toughness improves up to 30% HSC followed by gradual decrease in presence of bigger crystallites which promote brittle fracture. The origin of self-assembly in aliphatic PUs has been demonstrated through electronic structure calculations to form a loop structure with minimum intermolecular distance (2.2 Å) while that distance is quite large in aromatic polyurethanes (4.6 Å) that cannot form hydrogen bonds. The unique splintering of domain structure and its subsequent reformation under dynamic shear experiment has been established. © 2010 American Chemical Society.

Singh N.,Banaras Hindu University | Kumar M.,Banaras Hindu University | Kumar M.,Bose Institute of India | Singh R.K.,Banaras Hindu University
Asian Pacific Journal of Tropical Medicine | Year: 2012

The control of . Leishmania infection relies primarily on chemotherapy till date. Resistance to pentavalent antimonials, which have been the recommended drugs to treat cutaneous and visceral leishmaniasis, is now widespread in Indian subcontinents. New drug formulations like amphotericin B, its lipid formulations, and miltefosine have shown great efficacy to treat leishmaniasis but their high cost and therapeutic complications limit their usefulness. In addition, irregular and inappropriate uses of these second line drugs in endemic regions like state of Bihar, India threaten resistance development in the parasite. In context to the limited drug options and unavailability of either preventive or prophylactic candidates, there is a pressing need to develop true antileishmanial drugs to reduce the disease burden of this debilitating endemic disease. Notwithstanding significant progress of leishmanial research during last few decades, identification and characterization of novel drugs and drug targets are far from satisfactory. This review will initially describe current drug regimens and later will provide an overview on few important biochemical and enzymatic machineries that could be utilized as putative drug targets for generation of true antileishmanial drugs. © 2012 Hainan Medical College.

Saraswat K.,Banaras Hindu University | Shukla P.,Bhabha Atomic Research Center | Singh V.,Banaras Hindu University
Nuclear Physics A | Year: 2015

In this work, we calculate energy loss of heavy quark (charm and bottom) due to elastic collisions and gluon radiation in hot/dense medium. The collisional energy loss has been obtained using QCD calculations. The radiative energy loss is calculated using reaction operator formalism and generalized dead cone approach. We rederive the energy loss expression using same assumptions as generalized dead cone approach but obtain slightly different results. We also improve the model employed to calculate path length and the system evolution. The nuclear modification factors RAA including shadowing and energy loss are evaluated for B and D mesons and are compared with the measurements in PbPb collision at sNN=2.76 TeV and with the D meson and Heavy flavor (HF) electrons measurements in AuAu collision at sNN=200 GeV. The radiative energy loss calculated by reaction operator formalism added with collisional energy loss describes the RHIC HF electron suppression in high pT range. It also describes the LHC measurement of B meson suppression but overestimates the suppression of D meson. The radiative energy loss from generalized dead cone approach describes the charm suppression at both RHIC as well as LHC energies and requires energy loss due to collisions to be added in order to describe the bottom suppression at LHC. © 2015.

Kumar A.,Banaras Hindu University | Dubey N.K.,Banaras Hindu University | Srivastava S.,National Botanical Research Institute NBRI
Industrial Crops and Products | Year: 2013

Raw materials (roots) of Rauvolfia serpentina were found associated with various storage moulds. During mycological screening, total 887 fungal isolates were recovered and among them Aspergillus flavus exhibited the highest relative density (35.74%). The essential oil (EO) of Ocimum sanctum was isolated through Clevenger's hydro-distillation apparatus and investigated against A. flavus LHPRS7, isolated from raw materials. The GC-MS analysis of EO showed 41 considerable peaks. Eugenol (61.30%) was found as major component followed by β-Caryophyllene (11.89%) and Germacrene D (9.14%). The minimum inhibitory concentration (MIC) of O. Sanctum against A. flavus was found at 0.3μlml-1 while aflatoxin B1 production was completely checked at 0.2μlml-1. The O. sanctum EO exhibited broad fungitoxic spectrum and also found efficacious in reducing fungal incidence during in vivo study. The EO reduces the number of A. flavus isolates up to 62.94, 67.87 and 74.01% fumigated at concentration 0.3, 0.5 and 1.0μlml-1 respectively. The HPTLC (high performance thin layer chromatography) analysis of raw materials in in vivo study reveals that alkaloid ajmaline was firmly degraded by fungal contamination while in the samples fumigated with O. sanctum EO, ajmaline was protected from fungal degradation due to antifungal efficacy of EO. The prospects of exploitation of O. sanctum EO as acceptable plant based additive in qualitative as well as quantitative control of biodeterioration of herbal raw materials have been discussed. © 2012 Elsevier B.V.

Sundar S.,Banaras Hindu University | Chakravarty J.,Banaras Hindu University | Agarwal D.,Banaras Hindu University | Rai M.,Banaras Hindu University | Murray H.W.,New York Medical College
New England Journal of Medicine | Year: 2010

BACKGROUND: Some 50% of patients with visceral leishmaniasis (kala-azar) worldwide live in the Indian state of Bihar. Liposomal amphotericin B is an effective treatment when administered in short courses. We wanted to determine whether the efficacy of a single infusion of liposomal amphotericin B was inferior to conventional parenteral therapy, consisting of 15 alternate-day infusions of amphotericin B deoxycholate. METHODS: In this open-label study, we randomly assigned 412 patients in a 3:1 ratio to receive either liposomal amphotericin B (liposomal-therapy group) or amphotericin B deoxycholate (conventional-therapy group). Liposomal amphotericin B (at a dose of 10 mg per kilogram of body weight) was given once, and patients were discharged home 24 hours later. Amphotericin B deoxycholate, which was administered in 15 infusions of 1 mg per kilogram, was given every other day during a 29-day hospitalization. We determined the cure rate 6 months after treatment. RESULTS: A total of 410 patients - 304 of 304 patients (100%) in the liposomal-therapy group and 106 of 108 patients (98%) in the conventional-therapy group - had apparent cure responses at day 30. Cure rates at 6 months were similar in the two groups: 95.7% (95% confidence interval [CI], 93.4 to 97.9) in the liposomal-therapy group and 96.3% (95% CI, 92.6 to 99.9) in the conventional-therapy group. Adverse events in the liposomal-therapy group were infusion-related fever or rigors (in 40%) and increased anemia or thrombocytopenia (in 2%); such events in the conventional-therapy group were fever or rigors (in 64%), increased anemia (in 19%), and hypokalemia (in 2%). Nephrotoxicity or hepatotoxicity developed in no more than 1% of patients in each group. CONCLUSIONS: A single infusion of liposomal amphotericin B was not inferior to and was less expensive than conventional therapy with amphotericin B deoxycholate. ( number, NCT00628719.) Copyright © 2010 Massachusetts Medical Society.

Samai S.,Banaras Hindu University | Chanda T.,Banaras Hindu University | Ila H.,New Chemistry Unit | Singh M.S.,Banaras Hindu University
European Journal of Organic Chemistry | Year: 2013

An efficient and highly regioselective one-pot three-component synthesis of previously inaccessible and synthetically demanding 3-(cycloalkyl/alkyl/ arylamino)-5-aryl/alkylisoxazoles has been achieved by the cyclocondensation of β-oxo dithioesters, amines and hydroxylamine in ethanol at reflux. This transformation proceeds via an in situ generated β-oxothioamide by the reaction of the β-oxo dithioester and amine, which undergoes nucleophilic attack by hydroxylamine followed by intramolecular cyclization with the oxo functionality and subsequent dehydration to give 5-substituted 3-aminoisoxazoles as a single regioisomer in good yields. Furthermore, the mechanism of the reaction has been established experimentally and shown to be in agreement with the hard and soft (Lewis) acid and base (HSAB) theory. A highly regioselective synthesis of 5-substituted 3-aminoisoxazoles has been achieved by a one-pot three-component coupling of β-oxo dithioesters, amines and hydroxylamine in ethanol at reflux via an in situ generated β-oxo thioamide intermediate. The mechanism of the reaction has been established experimentally and shown to be in agreement with the HSAB theory. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Parchur A.K.,Banaras Hindu University | Ningthoujam R.S.,Bhabha Atomic Research Center
RSC Advances | Year: 2012

Rod-like shape particles of tetragonal phase Li+ co-doped YPO4:Eu samples are prepared by using a polyol method at low temperature (∼100-120 °C for 1 h). Li+ co-doping enhances the crystalline nature of the sample and reduces the agglomeration among the particles. The shift in the reflection peaks of the tetragonal phase to the lower 2θ angle in the X-ray diffraction pattern indicates the occupancy of Li+ ions in the interstitial sites of the host lattice. The point group symmetry of Y3+/Eu3+ in YPO4 is demonstrated in simple representation. © 2012 The Royal Society of Chemistry.

News Article | February 15, 2017

With climate change in our own era becoming increasingly evident, it's natural to wonder how our ancestors may have dealt with similar environmental circumstances. New research methods and technologies are able to shed light on climate patterns that took place thousands of years ago, giving us a new perspective on how cultures of the time coped with variable and changing environments. A new article in the February issue of Current Anthropology explores the dynamics of adaptation and resilience in the face of a diverse and varied environmental context, using the case study of South Asia's Indus Civilization (c.3000-1300 BC). Integrating research carried out as part of the Land, Water and Settlement project -- part of an ongoing collaboration between the University of Cambridge and Banaras Hindu University -- that worked in northwest India between 2007 and 2014, the article looks at how Indus populations in north-west India interacted with their environment, and considers how that environment changed during periods of climate change. Lead author, Dr. Cameron Petrie of the Division of Archaeology, University of Cambridge notes that "for most ancient complex societies, water was a critical factor, and the availability of water and the way that it was managed and used provide critical insight into human adaptation and the resilience of subsistence practices". Most early complex societies developed in regions where the climatic parameters faced by ancient subsistence farmers were varied, but not especially diverse. The Indus Civilization developed in a specific environmental context, where the winter and summer rainfall systems overlapped. There is now evidence to show that this region was subject to climate change during the period when the Indus Civilization was at its height (c.2500-1900 BC). The Indus Civilization therefore provides a unique opportunity to understand how an ancient society coped with diverse and varied ecologies and change in the fundamental and underlying environmental parameters. In the early Holocene, the Indus Civilization was situated in proximity to Kotla Dahar, a deep lake, implying regular and consistent rainfall input to offset evaporation, which given its location, would have been primarily monsoonal. The lake showed evidence for two dramatic decreases in monsoon rainfall and a progressive lowering of the lake level. The second of these shows Kotla Dahar becoming completely ephemeral ca. 2200-2000 BC as a result of an abrupt weakening of the monsoon, and the weakening of the monsoon is visible in speleothem records in Oman and northeast India. The proximity of the Kotla Dahar record to the area occupied by Indus populations shows that climate must be formally considered as a contributing parameter in the process of Indus deurbanization, at least in the context of the plains of northwest India. It has long been hypothesized that there was variation in the subsistence practices used by Indus populations and this fits with the theme of coping with diverse environments. Petrie comments that "we argue that rather than being forced to intensify or diversify subsistence practices in response to climatic change, we have evidence for the use of millet, rice, and tropical pulses in the pre-urban and urban phases of the Indus Civilization. This evidence suggests that local Indus populations were already well adapted to living in varied and variable environmental conditions before the development of urban centers. It is also possible that these adaptations were beneficial when these populations were faced with changes to the local environment that were probably beyond the range of variation that they typically encountered". The article hopes to invigorate discussion about human-environment interactions and their relationship to processes of cultural transformation. The collaborative Land, Water and Settlement project laid the platform for the TwoRains project, which was awarded funding by the European Research Council in 2015 and will run until 2020.

Ci L.,Rice University | Song L.,Rice University | Jin C.,Japan National Institute of Advanced Industrial Science and Technology | Jariwala D.,Rice University | And 11 more authors.
Nature Materials | Year: 2010

Two-dimensional materials, such as graphene and monolayer hexagonal BN (h-BN), are attractive for demonstrating fundamental physics in materials and potential applications in next-generation electronics. Atomic sheets containing hybridized bonds involving elements B, N and C over wide compositional ranges could result in new materials with properties complementary to those of graphene and h-BN, enabling a rich variety of electronic structures, properties and applications. Here we report the synthesis and characterization of large-area atomic layers of h-BNC material, consisting of hybridized, randomly distributed domains of h-BN and C phases with compositions ranging from pure BN to pure graphene. Our studies reveal that their structural features and bandgap are distinct from those of graphene, doped graphene and h-BN. This new form of hybrid h-BNC material enables the development of bandgap-engineered applications in electronics and optics and properties that are distinct from those of graphene and h-BN. © 2010 Macmillan Publishers Limited. All rights reserved.

Singh A.K.,Banaras Hindu University | Singh S.,Banaras Hindu University | Kumar D.,Banaras Hindu University | Rai D.K.,Banaras Hindu University | And 2 more authors.
Optics Letters | Year: 2012

Low-power-threshold cw laser-induced incandescence (CWLII) has been observed in La2O3:Er3+-Yb3+ phosphor on excitation by a 976 nm IR laser. It is suggested that incandescence originates from the extensive heating induced by the nonradiative processes taking place following the laser excitation. Other mechanisms for similar observations have also been suggested in the literature and have been discussed with the present observations. The estimated temperature for the CWLII approaches around 2650 K, and this seems to provide an effective way to rapidly attain high temperature in nano/microvolumes of phosphor. The phosphor exhibited efficient upconversion, and the ratio of the 2H11?2 → 4I15?2 and 4S3?2 → 4I15?2 band intensities of Er3+ permits measurement of the temperature rise, from a distance. © 2012 Optical Society of America.

Singh M.P.,Banaras Hindu University | Singh M.P.,University of Aberdeen | Singh R.K.,Banaras Hindu University | Chandra S.,Banaras Hindu University
Progress in Materials Science | Year: 2014

Ionic liquids are emerging as important materials for applications in electrochemical devices, green chemistry etc. For device applications, ionic liquids are generally, either incorporated in polymer matrices or confined in porous matrices (giving rise to an interesting class of materials 'Ionogels'). This review deals with the science and technological applications of ionic liquids confined in nano-pores. A comprehensive overview is given about the experimental studies dealing with the changes in the physico-chemical properties of ionic liquids like thermal phase transition, stability, dynamical behavior, optical properties etc. Recent theoretical studies highlighting the layering and structural heterogeneity of ionic liquids confined in nano-pores are also discussed. To make the review self-reading, basic ideas about ionic liquids and the phenomena of confinement are also briefly included. © Georg Thieme Verlag Stuttgart New York.

Singh N.,CSIR - Central Electrochemical Research Institute | Chikara S.,Xcelris Genomics | Sundar S.,Banaras Hindu University
PLoS ONE | Year: 2013

Background: Known as 'neglected disease' because relatively little effort has been applied to finding cures, leishmaniasis kills more than 150,000 people every year and debilitates millions more. Visceral leishmaniasis (VL), also called Kala Azar (KA) or black fever in India, claims around 20,000 lives every year. Whole genome analysis presents an excellent means to identify new targets for drugs, vaccine and diagnostics development, and also provide an avenue into the biological basis of parasite virulence in the L. donovani complex prevalent in India. Methodology/Principal Findings: In our presently described study, the next generation SOLiD™ platform was successfully utilized for the first time to carry out whole genome sequencing of L. donovani clinical isolates from India. We report the exceptional occurrence of insect trypanosomatids in clinical cases of visceral leishmaniasis (Kala Azar) patients in India. We confirm with whole genome sequencing analysis data that isolates which were sequenced from Kala Azar (visceral leishmaniasis) cases were genetically related to Leptomonas. The co-infection in splenic aspirate of these patients with a species of Leptomonas and how likely is it that the infection might be pathogenic, are key questions which need to be investigated. We discuss our results in the context of some important probable hypothesis in this article. Conclusions/Significance: Our intriguing results of unusual cases of Kala Azar found to be most similar to Leptomonas species put forth important clinical implications for the treatment of Kala Azar in India. Leptomonas have been shown to be highly susceptible to several standard leishmaniacides in vitro. There is very little divergence among these two species viz. Leishmania sp. and L. seymouri, in terms of genomic sequence and organization. A more extensive perception of the phenomenon of co-infection needs to be addressed from molecular pathogenesis and eco-epidemiological standpoint. © 2013 Singh et al.

Rao N.V.C.,Banaras Hindu University | Wu F.-Y.,CAS Institute of Geology and Geophysics | Mitchell R.H.,Lakehead University | Li Q.-L.,CAS Institute of Geology and Geophysics | Lehmann B.,Clausthal University of Technology
Chemical Geology | Year: 2013

We report new U-Pb ages of groundmass perovskite determined by secondary ion mass spectrometry, trace element, and Sr and Nd isotopic compositions for twelve kimberlites emplaced in three different fields from the Eastern Dharwar craton, southern India. Diamondiferous kimberlites from the Wajrakarur field gave ages ranging from 1099±12Ma to 1129±12Ma. The non-diamondiferous kimberlites from the Narayanpet field gave ages ranging from 1123±17Ma to 1141±18Ma. One kimberlite (Siddanpalle cluster) from the poorly-diamondiferous Raichur field has an indistinguishable age of 1093±18Ma. Our data contribute to the evidence for a near-synchronous late Mesoproterozoic kimberlite emplacement event in the Eastern Dharwar craton at 1.1Ga and increases the spatial extent of this tectonomagmatic event. The perovskite U-Pb ages of kimberlites determined in this study are similar to those of the diamondiferous Majhgawan and Bunder lamproites of the Bundelkhand craton (northern India) and Nuapada lamproites of Bastar craton, (central India), but are clearly much younger than the 1.5Ga ages recently reported for some of the Krishna lamproites of the Eastern Dharwar Craton. Regardless of their contemporaneous ages, initial 87Sr/86Sr ratios of Narayanpet perovskites are notably higher (0.70302-0.70339) than those (0.70240-0.70255) from the Wajrakarur Field. Similarly, the εNd(t) of Narayanpet perovskite (+0.6 to +1.9) is relatively lower than that (+2 to +2.9) of the Wajrakarur perovskites and provides clear evidence for the involvement of distinct isotopic mantle sources for these different kimberlite fields. The Raichur kimberlite has an indistinguishable initial 87Sr/86Sr ratio (0.70305) and εNd(t) (+1.4) to the Narayanpet kimberlites. The perovskite depleted mantle model ages (TDM) of the Wajrakarur and Narayanpet kimberlites range from 1.3 to 1.5Ga and are inferred to be distant effects related to the break-up of the Columbia supercontinent and separation of the North China craton and Indian shield from the Laurentia continent. A variably-enriched metasomatised sub-continental lithospheric mantle overprinted by an asthenospheric signature within a short time-span can account for the distinct isotopic signals of kimberlites in different fields of the Eastern Dharwar Craton and their "transitional" petrological and geochemical characteristics compared to archetypal kimberlites. © 2012 Elsevier B.V.

Chowdhury P.,University of Calcutta | Kudela K.,Slovak Academy of Sciences | Dwivedi B.N.,Banaras Hindu University
Solar Physics | Year: 2013

Galactic cosmic rays (GCRs) encounter an outward-moving solar wind with cyclic magnetic-field fluctuation and turbulence. This causes convection and diffusion in the heliosphere. The GCR counts from the ground-based neutron monitor stations show intensity changes that are anti-correlated with the sunspot numbers with a lag of a few months. GCRs experience various types of modulation from different solar activity features and influence space weather and the terrestrial climate. In this work, we investigate certain aspects of the GCR modulation at low cut-off rigidity (Rc≈1 GV) in relation to some solar and geomagnetic indices for the entire solar cycle 23 (1996 - 2008). We separately study the GCR modulation during the ascending phase of cycle 23 including its maximum (1996 - 2002) and the descending phase including its minimum (2003 - 2008). We find that during the descending phase, the GCR recoveries are much faster than those of the solar parameters with negative time-lag. The results are discussed in light of modulation models, including drift effects and previous results. © 2013 Springer Science+Business Media Dordrecht.

Singh A.,Banaras Hindu University | Sharma R.K.,Banaras Hindu University | Agrawal M.,Banaras Hindu University | Marshall F.M.,University of Sussex
Food and Chemical Toxicology | Year: 2010

The present study was conducted to assess the risk to human health by heavy metals (Cd, Cu, Pb, Zn, Ni and Cr) through the intake of locally grown vegetables, cereal crops and milk from wastewater irrigated site. Milk is not directly contaminated due to wastewater irrigation, but is an important route of food chain transfer of heavy metals from grass to animals. Heavy metal concentrations were several fold higher in all the collected samples from wastewater irrigated site compared to clean water irrigated ones. Cd, Pb and Ni concentrations were above the 'safe' limits of Indian and WHO/FAO standards in all the vegetables and cereals, but within the permissible limits in milk samples. The higher values of metal pollution index and health risk index indicated heavy metal contamination in the wastewater irrigated site that presented a significant threat of negative impact on human health. Rice and wheat grains contained less heavy metals as compared to the vegetables, but health risk was greater due to higher contribution of cereals in the diet. The study suggests that wastewater irrigation led to accumulation of heavy metals in food stuff causing potential health risks to consumers. © 2009 Elsevier Ltd. All rights reserved.

Singh A.,Banaras Hindu University | Agrawal M.,Banaras Hindu University | Marshall F.M.,University of Sussex
Ecological Engineering | Year: 2010

Long-term use of industrial and domestic wastewater for irrigation leads to accumulation of heavy metals in the soil and consequently in the edible portion of the plants. This study examined the role of fertilizers in reducing the heavy metal availability in the soil, and subsequent uptake in Beta vulgaris L. (var. All green). The effects of organic fertilizer as farmyard manure (FYM), commercial inorganic nitrogen, phosphorus and potassium (NPK) and a combination of FYM. +. N were compared with control having no fertilization on physico-chemical properties of the soil and heavy metal concentrations in the soil and plants. Soil treatments led to changes in the physico-chemical properties of the soil, modifying the phytoavailability of heavy metals. Phytoavailabilty of Cd, Cu, Pb, Zn, Mn, Ni and Cr was lowest in FYM- and highest in NPK- treated soil, compared to the untreated control. The yield of B. vulgaris was also highest in FYM-treated soil. As the application of FYM alone and in combination with N resulted in reduced heavy metal uptake and better yield, it may be considered an easy and cost-effective technique for reducing the levels of contamination in food crops. © 2010 Elsevier B.V.

Chowdhury P.,University of Calcutta | Dwivedi B.N.,Banaras Hindu University
Solar Physics | Year: 2011

We investigate the presence and temporal evolution of short- and intermediate-term periodicities in the daily data of sunspot numbers and coronal index for the time span from May 1996 to December 2008, which covers the entire Solar Cycle 23. The daily sunspot number data have been analyzed for the full disk, and for northern and southern hemispheres of the Sun. Using the wavelet power spectrum technique, we find a number of quasi-periodic oscillations in all the data sets. We also find a prominent period of 22 to 35 days in the high-frequency range, and detect the Rieger period of 150 to 160 days in both data sets during different phases of Cycle 23. We also detect ~1. 3 year oscillation in both sunspot and coronal index time series. In addition, we find a number of other short and mid-term periods. We discuss possible explanations of the observed periodicities in the light of previous results and existing numerical models. © 2011 Springer Science+Business Media B.V.

Tiwari S.P.,Indian School of Mines | Srivastava A.K.,Banaras Hindu University
Fuzzy Sets and Systems | Year: 2013

This paper shows that observations made by different authors at different times regarding one-to-one correspondence between the family of fuzzy preorders on a nonempty set and the family of all fuzzy topologies on this set satisfying certain extra conditions are essentially equivalent. © 2012 Elsevier B.V. All rights reserved.

Singh G.S.P.,Banaras Hindu University | Singh U.K.,Indian School of Mines
International Journal of Rock Mechanics and Mining Sciences | Year: 2010

A reliable prediction of the caving behavior of strata and support capacity requirement for longwall workings has always been a challenge for rock mechanics researchers and mine planning engineers. It is very important for successful planning and implementation of high capacity longwall projects to have proper selection of site and compatible roof supports, to ensure safe operation of longwall face especially in massive and difficult to cave strata conditions. This paper illustrates a numerical modeling based integrated approach for predicting the progressive caving behavior of strata and optimum capacity requirement of powered support for longwall working in a given geo-mining and strata condition. A set of design criteria for selection of optimal capacity support integrating the field experience and the numerical modeling results of longwall panels, operated in a widely varying strata conditions in different coalfields of India. Case studies of two typical longwall workings are presented to assess the caving behavior and support requirement for safe operation of longwall working under the site specific regular and en masse caving strata conditions. © 2009 Elsevier Ltd. All rights reserved.

Upadhyay K.K.,Banaras Hindu University | Mishra R.K.,Banaras Hindu University | Kumar V.,Banaras Hindu University | Chowdhury P.K.R.,Chembiotek Research International
Talanta | Year: 2010

A new coumarin based hydrazone (receptor 1) synthesized by modifying one of our earlier reported receptor detected fluoride ion selectively through naked eye in aq. DMSO (5:95, v/v). It was also able to detect fluoride through naked eye in a toothpaste sample. The addition of 1 equiv. of fluoride as its tetrabutylammonium salt to the 5 × 10-5 M aq. DMSO solution of the receptor 1 produced red color while the similar addition of acetate produced faint pink color. The dihydrogenphosphate and a variety of other anions were not able to produce any significant color change with receptor 1 under similar experimental conditions. The corresponding UV-vis measurements showed a bathochromic shifting of 455 nm band of receptor 1 to 514 and 484 nm for fluoride and acetate, respectively. The non-linear fittings of corresponding UV-vis titration data in 1:1 binding equation yielded association constants in 105:1 ratio for fluoride and acetate, respectively. The 1H NMR titrations studies shade further light on their mode of binding with receptor 1. The quantum mechanical calculations through time dependant density functional theory (TD-DFT) using basis set b3lyp/6-311g** supported our experimental findings nicely. © 2010 Elsevier B.V. All rights reserved.

Matharu Z.,k-Technology | Matharu Z.,University of Delhi | Bandodkar A.J.,Banaras Hindu University | Bandodkar A.J.,University of California at San Diego | And 4 more authors.
Chemical Society Reviews | Year: 2012

Organization of biomolecules in two/three dimensional assemblies has recently aroused much interest in nanobiotechnology. In this context, the development of techniques for controlling spatial arrangement and orientation of the desired molecules to generate highly-ordered nanostructures in the form of a mono/multi layer is considered highly significant. The studies of monolayer films to date have focused on three distinct methods of preparation: (i) the Langmuir-Blodgett (LB) technique, involving the transfer of a monolayer assembled at the gas-liquid interface; (ii) self-assembly at the liquid-solid interface, based on spontaneous adsorption of desired molecules from a solution directly onto a solid surface; and (iii) Layer-by-layer (LBL) self-assembly at a liquid-solid interface, based on inter-layer electrostatic attractions for fabrication of multilayers. A variety of monolayers have been utilized to fabricate biomolecular electronic devices including biosensors. The composition of a monolayer based matrix has been found to influence the activity(ies) of biomolecule(s). We present comprehensive and critical analysis of ordered molecular assemblies formed by LB and self-assembly with potential applications to affinity biosensing. This critical review on fundamentals and application of ordered molecular assemblies to affinity biosensing is likely to benefit researchers working in this as well as related fields of research (401 references). © 2012 The Royal Society of Chemistry.

Rao N.V.C.,Banaras Hindu University | Lehmann B.,Clausthal University of Technology | Mainkar D.,Directorate of Geology and Mining | Belyatsky B.,Russian Academy of Sciences
Contributions to Mineralogy and Petrology | Year: 2011

We present mineral chemistry, geochemistry and Sr and Nd isotope data of drillcore samples from the Late Cretaceous (65 Ma), diamondiferous Behradih ultramafic pipe, Bastar craton, Central India, which is emplaced synchronous with the Deccan flood basalt eruption. The rock is affected by pervasive serpentine-talc-carbonate alteration and consists of pelletal lapilli and variously sized olivine and phlogopite macrocrysts, set in a groundmass of abundant clinopyroxene, chrome spinel, apatite, Fe-rich perovskite (<50 μm), zircon, titanite, rutile and calcite. Mineralogical studies identify the Behradih pipe as orangeite (formerly termed as Group II kimberlite) and establish the occurrence of such rocks outside the Kaapvaal craton, southern Africa. As the age of the Behradih orangeite overlaps with that of the main phase of the Deccan flood basalt magmatism, we infer a common tectonomagmatic control vis-a-vis the Deccan-related mantle plume. Trace element ratios and the Nd isotope signatures of the Behradih pipe imply that the Deccan plume has only contributed heat, but not substantial melt, to the Behradih magma with a cause-and-consequence relationship between them. Our study highlights (a) a striking similarity in the genesis of Late Cretaceous orangeites associated with the continental flood basalts in the Kaapvaal and Bastar cratons but related to different mantle plumes and (b) the role of plume-lithosphere interaction in the generation of orangeites. © 2010 Springer-Verlag.

Kumari K.,Banaras Hindu University | Raghuvanshi D.S.,Banaras Hindu University | Jouikov V.,French National Center for Scientific Research | Singh K.N.,Banaras Hindu University
Tetrahedron Letters | Year: 2012

An efficient, rapid, and green synthesis of functionalized pyrazoles has been accomplished under solvent-free conditions by the reaction of phenyl hydrazine, aldehydes and ethyl acetoacetate. This approach exploits the synthetic potential of microwave irradiation and scandium triflate combination and offers many advantages such as excellent product yields, shorter reaction time, easy isolation of products, and environmentally benign reaction conditions. © 2011 Elsevier Ltd. All rights reserved.

Kumar S.,Banaras Hindu University | Chatterjee S.,Banaras Hindu University | Chattopadhyay K.K.,Jadavpur University | Ghosh A.K.,Banaras Hindu University
Journal of Physical Chemistry C | Year: 2012

Structural, Raman, and optical properties of sol-gel derived Zn 1-xMn xO (0≤x ≤ 0.06) nanoparticles have been investigated. The crystallite structure, morphology, and size estimation have been performed by X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM). To study the crystalline quality, structural disorder and defects in the host lattice, we have employed Raman Spectroscopy. The wurtzite structure and formation of tetrahedral coordination of the oxygen ions surrounding the zinc ions has been confirmed by FTIR analysis. Optical properties have been studied by UV-vis and PL spectroscopy. UV-vis measurements show that the band gap is increased with increasing Mn concentration. This may be attributed to the orbital hybridizations that are prevailed throughout the whole range of Mn doping. Variation of resistivity with temperature shows that thermally activated conduction (Arrhenius) mechanism is valid in the high-temperature region (T > 250 K), whereas Mott's variable-range hopping (VRH) mechanism is valid in low-temperature region (T < 250 K). Variation of the activation energy estimated from the resistivity measurement (Arrhenius law) qualitatively follows the variation of the optical band gap. © 2012 American Chemical Society.

Singh R.K.,Indian Institute of Technology Kanpur | Singh R.K.,Banaras Hindu University | Mishra S.,Indian Institute of Technology Kanpur
IEEE Transactions on Industrial Electronics | Year: 2013

This paper presents a magnetically coupled feedback-clamped optimal bidirectional battery charger. The proposed charger acts as a current source, i.e., acts in constant-current (CC) mode with a controlled output current in case of deep discharge of a battery, and as a voltage source, i.e., acts in constant-voltage (CV) mode with a controlled output voltage for near-100% battery state of charge. The proposed circuit is universal from the battery voltage point of view, i.e., can charge a battery with any given voltage rating, and adaptive from the optimum charging current requirement viewpoint, i.e., can adapt to the optimum battery charging current. The presented solution uses a magnetically coupled bidirectional converter topology. In order to make the system feedback controlled during the whole cycle of charging, the regulation loop is clamped, and hence, automatic and smooth transition from the CC to CV mode is achieved without the need of any extra switching circuit or control loop. Experimental and simulation results for a 250-W prototype are presented to verify the proposed system. The prototype shows maximum efficiencies of 90.24% under boost mode and 92.7% under buck mode of operation. The performance of the charger is verified using two different 12-V-7-Ah and 12-V-32-Ah lead-acid batteries. © 2012 IEEE.

Faizal M.,University of Waterloo | Upadhyay S.,Banaras Hindu University | Mandal B.P.,Banaras Hindu University
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2014

In this paper we analyze the ABJM theory in N=1 superspace. Firstly we study the linear and non-linear BRST transformations for the ABJM theory. Then we derive the finite field dependent version of these BRST (FFBRST) transformations. Further we show that such FFBRST transformations relate the generating functional in linear gauge to the generating functional in the non-linear gauge of ABJM theory. © 2014 The Authors.

Singh Y.N.,University of Lucknow | Singh S.K.,Banaras Hindu University | Gupta P.,Indian Institute of Technology Kanpur
Pattern Recognition Letters | Year: 2012

This paper explores the effectiveness of a novel multibiometric system that is resulted from the fusion of the electrocardiogram (ECG) with an unobtrusive biometric face and another biometric fingerprint which is known to be a least obtrusive for efficient individual authentication. The unimodal systems of the face and the fingerprint biometrics are neither secure nor they can achieve the optimum performance. Using the ECG signal as one of the biometrics offer advantage to a multibiometric system that ECG is inherited to an individual which is confidential, secured and difficult to be forged. It has an inherent feature of vitality signs that ensures a strong protection against spoof attacks to the system. Transformation based score fusion technique is used to measure the performance of the fused system. In particular, the weighted sum of score rule is used where weights are computed using equal error rate (EER) and match score distributions of the unimodal systems. The performance of the proposed multibiometric system is measured using EER and receiver operating characteristic (ROC) curve. The results show the optimum performance of the multibiometric system fusing the ECG signal with the face and fingerprint biometrics which is achieved to an EER of 0.22%, as compared to the unimodal systems that have the EER of 10.80%, 4.52% and 2.12%, respectively for the ECG signal, face and fingerprint biometrics. © 2012 Elsevier B.V. All rights reserved.

Upadhyay S.,Indian Institute of Technology Kanpur | Mandal B.P.,Banaras Hindu University
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2015

We develop the finite field-dependent BRST (FFBRST) transformation for arbitrary spin-s conformal field theories. We discuss the novel features of the FFBRST transformation in these systems. To illustrate the results we consider the spin-1 and spin-2 conformal field theories in two examples. Within the formalism we found that FFBRST transformation connects the generating functionals of spin-1 and spin-2 conformal field theories in linear and non-linear gauges. Further, the conformal field theories in the framework of FFBRST transformation are also analyzed in Batalin-Vilkovisky (BV) formulation to establish the results. © 2015 The Authors.

Singh R.K.,Indian Institute of Technology Kanpur | Singh R.K.,Banaras Hindu University | Mishra S.,Indian Institute of Technology Kanpur
IEEE Transactions on Industrial Electronics | Year: 2013

In the modern point-of-load (POL) applications, a number of low- and medium-power converters are used very close to the actual load. These applications require superior dynamic response and better power processing density to save space on the motherboard. Hysteretic modulators are one of the obvious choices for these applications because of their superior dynamic response with minimal number of filter capacitors. This paper presents a new carrier (synthetic ripple based)-generation-based digital hysteretic modulator for POL converters. The proposed structure creates a piecewise linear synthetic ripple using sensed converter voltages, without the need of direct inductor current sensing. The artificial synthetic ripple is then added to the output voltage and fed as a carrier to the hysteretic comparator, which helps in natural load current feedforward. This proposed digital modulator helps in the reduction of the output capacitors and exhibits superior large-signal dynamics for a POL converter. It is a simple solution and gives immediate fault detection (within one switching cycle) in case of the main switch (top MOSFET) failure of the converter, thus providing adequate protection to the microprocessor load. Analysis, simulation, and experimental results on a 2-V/10-A 20-W single-phase prototype are presented to verify the properties of the proposed modulator. © 1982-2012 IEEE.

Faizal M.,University of Waterloo | Upadhyay S.,Indian Institute of Technology Kanpur | Mandal B.P.,Banaras Hindu University
International Journal of Modern Physics A | Year: 2015

In this paper we will analyze the anti-BRST symmetries of Bagger-Lambert-Gustavsson (BLG) theory in presence of a boundary. We will analyze these symmetries in both linear and nonlinear gauges. We will also derive the finite field version of the anti-BRST transformations for the BLG theory in presence of a boundary. These finite field transformations will be used to relate generating functional in linear gauge to the generating functional in the nonlinear gauge. © 2015 World Scientific Publishing Company.

Chaturvedi T.P.,Institute of Medical science | Upadhayay S.N.,Banaras Hindu University
Indian Journal of Dental Research | Year: 2010

Various types of metallic orthodontic appliances are used in the management of malocclusion. These appliances are placed in oral environnent under many stresses and variations such as masticatory forces, appliance loading, temperature fluctuations, varieties of ingested food and saliva. These metals undergo electrochemical reactions with the oral environment resulting in dissolution or formation of chemical compounds. Various microorganisms and many aggressive ions containing oral environment can cause material degradation (corrosion) and its associated problems during long time exposure. Orthodontic alloys must have excellent corrosion resistance to the oral environment, which is highly important for biocompatibility as well as for orthodontic appliance durability. This article reviews various aspects of corrosion (surface degradation) of orthodontic alloys. It explores the emerging research strategies for probing the biocompatibility of materials. During orthodontic treatment, use of nickel free, better corrosion resistance alloys and less use of fluoride containing toothpaste or gel is expected.

Agency: Cordis | Branch: FP7 | Program: CP-SICA | Phase: HEALTH-2007-2.3.4-1 | Award Amount: 3.97M | Year: 2008

Visceral leishmaniasis (VL), one of the most-neglected infectious diseases, has an annual incidence of 500,000 cases. Early treatment is a major pillar of the current program for VL elimination on the Indian sub-continent. However, the arsenal of available drugs is very limited, and their use is jeopardized by drug resistance. Combination regimens for VL are under clinical development, but it will take several more years to change the drug policy. Meanwhile, the effectiveness of current drugs needs to be safeguarded in order to cure patients and ensure unremitting sustainment of VL control. For this, the uninterrupted supply of quality drugs, the promotion of treatment compliance and, the monitoring of treatment effectiveness and of drug resistance will be pivotal. The latter demands improved knowledge and know-how, hence clinical and laboratory research are urgently needed to support the drug policy of the VL elimination program. The present multi-disciplinary proposal addresses these needs: we aim to develop, evaluate and disseminate new tools for the assessment of drug resistance in L. donovani as well as innovative methodologies for monitoring Kala-Azar treatment effectiveness under routine conditions.

News Article | November 21, 2016

Latest research on archaeological sites of the ancient Indus Civilisation, which stretched across what is now Pakistan and northwest India during the Bronze Age, has revealed that domesticated rice farming in South Asia began far earlier than previously believed, and may have developed in tandem with - rather than as a result of - rice domestication in China. The research also confirms that Indus populations were the earliest people to use complex multi-cropping strategies across both seasons, growing foods during summer (rice, millets and beans) and winter (wheat, barley and pulses), which required different watering regimes. The findings suggest a network of regional farmers supplied assorted produce to the markets of the civilisation's ancient cities. Evidence for very early rice use has been known from the site of Lahuradewa in the central Ganges basin, but it has long been thought that domesticated rice agriculture didn't reach South Asia until towards the end of the Indus era, when the wetland rice arrived from China around 2000 BC. Researchers found evidence of domesticated rice in South Asia as much as 430 years earlier. The new research is published today in the journals Antiquity and Journal of Archaeological Science by researchers from the University of Cambridge's Division of Archaeology, in collaboration with colleagues at Banaras Hindu University and the University of Oxford. "We found evidence for an entirely separate domestication process in ancient South Asia, likely based around the wild species Oryza nivara. This led to the local development of a mix of 'wetland' and 'dryland' agriculture of local Oryza sativa indica rice agriculture before the truly 'wetland' Chinese rice, Oryza sativa japonica, arrived around 2000 BC," says study co-author Dr Jennifer Bates "While wetland rice is more productive, and took over to a large extent when introduced from China, our findings appear to show there was already a long-held and sustainable culture of rice production in India as a widespread summer addition to the winter cropping during the Indus civilisation." Co-author Dr Cameron Petrie says that the location of the Indus in a part of the world that received both summer and winter rains may have encouraged the development of seasonal crop rotation before other major civilisations of the time, such as Ancient Egypt and China's Shang Dynasty. "Most contemporary civilisations initially utilised either winter crops, such as the Mesopotamian reliance on wheat and barley, or the summer crops of rice and millet in China - producing surplus with the aim of stockpiling," says Petrie. "However, the area inhabited by the Indus is at a meteorological crossroads, and we found evidence of year-long farming that predates its appearance in the other ancient river valley civilisations." The archaeologists sifted for traces of ancient grains in the remains of several Indus villages within a few kilometers of the site called Rakhigari: the most recently excavated of the Indus cities that may have maintained a population of some 40,000. As well as the winter staples of wheat and barley and winter pulses like peas and vetches, they found evidence of summer crops: including domesticated rice, but also millet and the tropical beans urad and horsegram, and used radiocarbon dating to provide the first absolute dates for Indus multi-cropping: 2890-2630 BC for millets and winter pulses, 2580-2460 BC for horsegram, and 2430-2140 BC for rice. Millets are a group of small grain, now most commonly used in birdseed, which Petrie describes as "often being used as something to eat when there isn't much else". Urad beans, however, are a relative of the mung bean, often used in popular types of Indian dhal today. In contrast with evidence from elsewhere in the region, the village sites around Rakhigari reveal that summer crops appear to have been much more popular than the wheats of winter. The researchers say this may have been down to the environmental variation in this part of the former civilisation: on the seasonally flooded Ghaggar-Hakra plains where different rainfall patterns and vegetation would have lent themselves to crop diversification - potentially creating local food cultures within individual areas. This variety of crops may have been transported to the cities. Urban hubs may have served as melting pots for produce from regional growers, as well as meats and spices, and evidence for spices have been found elsewhere in the region. While they don't yet know what crops were being consumed at Rakhigarhi, Jennifer Bates points out that: "It is certainly possible that a sustainable food economy across the Indus zone was achieved through growing a diverse range of crops, with choice being influenced by local conditions. "It is also possible that there was trade and exchange in staple crops between populations living in different regions, though this is an idea that remains to be tested." "Such a diverse system was probably well suited to mitigating risk from shifts in climate," adds Cameron Petrie. "It may be that some of today's farming monocultures could learn from the local crop diversity of the Indus people 4,000 years ago." The findings are the latest from the Land, Water and Settlement Project, which has been conducting research on the ancient Indus Civilisation in northwest India since 2008.

Rao N.V.C.,Banaras Hindu University | Lehmann B.,Clausthal University of Technology
Earth-Science Reviews | Year: 2011

A clear-cut temporal and spatial relationship between small-volume, volatile-rich and highly potassic continental melt fractions, such as kimberlites and related rocks, and large-volume continental flood basalts exists in several Large Igneous Provinces (LIPs). Many of these LIPs are also widely regarded as products of mantle plume-lithosphere interactions. The small-volume melts either immediately pre-date or post-date or even are co-eval with the main flood basalt event. The overlap of ages between the flood basalts and the kimberlites very likely reflects a cause and effect relationship via mantle plumes. Recently discovered end-Cretaceous diamondiferous kimberlites (orangeites) in the Bastar craton of central India which are synchronous with the flood basalts, carbonatites, lamprophyres and alkaline rocks of the Deccan LIP provide an opportunity to re-evaluate the role of mantle plume-lithosphere interactions in the generation of these disparate magmas. The geographical zonation of the kimberlite-lamprophyre-carbonatite-alkaline rock spectrum in the Deccan LIP is inferred to reflect variable thickness of the pre-Deccan Indian lithosphere with a thinner lithosphere along the known rift zones of northwestern and western India and a thickened lithosphere underlying the Bastar craton of central India. This heterogeneity is thought to have controlled the volume of melt generation and melt ascent, as well as the ultimate alkaline magma type. These findings are supported by the regional lithospheric thickness map, generated from converting seismic shear wave velocities into temperature profiles, which clearly depicts that the present-day lithosphere beneath the Bastar craton is thicker than that in western and NW India where the centre of the Deccan plume-head was located. Thermal weakening of the sub-Bastar craton due to mantle plume-lithosphere interaction at the end-Cretaceous resulting in a thin-spot is suggested to have controlled the Deccan-related mafic dyke emplacement in the Bastar craton. © 2011 Elsevier B.V.

Murawski K.,Group of Astrophysics | Srivastava A.K.,Banaras Hindu University | Musielak Z.E.,University of Texas at Arlington | Musielak Z.E.,Kiepenheuer Institute for Solar Physics
Astrophysical Journal | Year: 2014

We present results of three-dimensional (3D) numerical simulations of a fast magnetic twister excited above a foot-point of the potential solar coronal arcade that is embedded in the solar atmosphere with the initial VAL-IIIC temperature profile, which is smoothly extended into the solar corona. With the use of the FLASH code, we solve 3D ideal magnetohydrodynamic equations by specifying a twist in the azimuthal component of magnetic field in the solar chromosphere. The imposed perturbation generates torsional Alfvén waves as well as plasma swirls that reach the other foot-point of the arcade and partially reflect back from the transition region. The two vortex channels are evident in the generated twisted flux-tube with a fragmentation near its apex which results from the initial twist as well as from the morphology of the tube. The numerical results are compared to observational data of plasma motions in a solar prominence. The comparison shows that the numerical results and the data qualitatively agree even though the observed plasma motions occur over comparatively large spatio-temporal scales in the prominence. © 2014. The American Astronomical Society. All rights reserved..

Ansari K.R.,Banaras Hindu University | Quraishi M.A.,Banaras Hindu University | Singh A.,Lovely Professional University
Corrosion Science | Year: 2014

Three Schiff's bases namely (3-phenylallylidene) amino-5-(pyridine-4-yl)-4H-1,2,4-triazole-3-thiol (SB-1), 3-mercapto-5 (pyridine-4-yl)-4H-1,2,4-triazole-4-yl) imino) methyl) phenol (SB-2) and (4-nitrobenzylidene) amino)-5-(pyridine-4-yl)-4H-1,2,4-triazole-3-thiol (SB-3) were synthesized and investigated as corrosion inhibitors for mild steel (MS) in 1M HCl. SB-1 exhibited best inhibition performance (96.6 η%) at 150mgL-1. The studied inhibitors follow Langmuir adsorption isotherm. Potentiodynamic polarization data suggests mixed-mode of corrosion inhibition. The effect of molecular structure on inhibition efficiency was investigated by theoretical calculations using density function theory (DFT) methods. Surface analysis supports the formation of a protective inhibitor film on the mild steel surface. © 2013 Elsevier Ltd.

Chalapathi Rao N.V.,Banaras Hindu University | Creaser R.A.,University of Alberta | Lehmann B.,Clausthal University of Technology | Panwar B.K.,Banaras Hindu University
Chemical Geology | Year: 2013

We report the first Re-Os isotope data for samples from Mesoproterozoic kimberlite and lamproite occurrences from the Eastern Dharwar craton and end-Cretaceous Kodomali orangeite from the Bastar craton, India. The Re concentrations of the kimberlites (n=10) range from 0.077 to 0.290 parts per billion (ppb) whereas the Os contents vary from 0.312 to 1.98ppb. The measured 187Os/188Os ratios range from 0.1143 to 0.1655. The calculated initial 187Os/188Os ratios range from 0.0967 to 0.1260, with low values indicating Re mobility on the whole-rock scale since crystallisation. The orangeite has a measured 187Os/188Os ratio of 0.1342 and a slightly higher initial 187Os/188Os value of 0.1330. On the other hand, the lamproites (n=3) display lower Re (0.031 to 0.279ppb) and Os (0.060 to 0.129ppb) contents. Their measured 187Os/188Os ratios (0.2398 to 0.7521) and their initial 187Os/188Os ratios (0.1891 to 0.5499) are significantly higher. A majority of the kimberlites display γOsi of -2.7 to -22.7 and imply their interaction with a depleted or unradiogenic source such as cratonic lithosphere. A regression age (involving 187Re/188Os vs 187Os/188Os) of 1008±410Ma for eight least altered kimberlites corresponds, within the error limits, to their emplacement age (1.1Ga) and negates mixing of a highly radiogenic low Os melt, similar to the lamproites, and lithospheric mantle in their genesis. The most Re-depleted kimberlite sample with the lowest present-day 187Os/188Os (0.1143) yields a model age (TMA) of 3.2Ga and a Re-depletion model age (TRD) of 2Ga. The TRD age reveals: (i) the involvement of Proterozoic lithosphere in the genesis of the kimberlites, (ii) coupling of the continental crust of the Eastern Dharwar craton and the underlying sub-continental lithospheric mantle from 2.5Ga to at least 1.1Ga, and (iii) its similarity with the emplacement age of large igneous provinces of similar age and magmatism in the Eastern Dharwar and Bastar cratons (India), the Superior Craton (Canada) and the Kaapvaal craton (southern Africa). However, two of the kimberlite samples (from Raichur and Narayanpet kimberlite fields) show positive γOs values ranging from 2.9 to 3.6 suggesting involvement of multiple sources (e.g., subduction, plume or metasomatised lithosphere) in their genesis. An enriched mantle source for the Kodomali orangeite (γOs=3) is also supported by its lower εNdi values. The lamproites have very radiogenic γOsi values of 56 to 355, similar to those displayed by the lamproites of the Italian peninsula, and indicate a source with elevated Re/Os, possibly a subducted component. Our study provides strong evidence for contrasting mantle sources for kimberlites and lamproites in the Eastern Dharwar craton, southern India. © 2012 Elsevier B.V.

Singh D.N.,Banaras Hindu University | Kumar A.,Banaras Hindu University | Sarbhai M.P.,Institute of Reservoir Studies | Tripathi A.K.,Banaras Hindu University
Applied Microbiology and Biotechnology | Year: 2012

Biogenic origin of the significant proportion of coal bed methane has indicated the role of microbial communities in methanogenesis. By using cultivation-independent approach, we have analysed the archaeal and bacterial community present in the formation water of an Indian coal bed at 600-700 m depth to understand their role in methanogenesis. Presence of methanogens in the formation water was inferred by epifluorescence microscopy and PCR amplification of mcrA gene. Archaeal 16S rRNA gene clone library from the formation water metagenome was dominated by methanogens showing similarity to Methanobacterium, Methanothermobacter and Methanolinea whereas the clones of bacterial 16S rRNA gene library were closely related to Azonexus, Azospira, Dechloromonas and Thauera. Thus, microbial community of the formation water consisted of predominantly hydrogenotrophic methanogens and the proteobacteria capable of nitrogen fixation, nitrate reduction and polyaromatic compound degradation. Methanogenic potential of the microbial community present in the formation water was elucidated by the production of methane in the enrichment culture, which contained 16S rRNA gene sequences showing close relatedness to the genus Methanobacterium. Microcosm using formation water as medium as well as a source of inoculum and coal as carbon source produced significant amount of methane which increased considerably by the addition of nitrite. The dominance of Diaphorobacter sp. in nitrite amended microcosm indicated their important role in supporting methanogenesis in the coal bed. This is the first study indicating existence of methanogenic and bacterial community in an Indian coal bed that is capable of in situ biotransformation of coal into methane. © 2011 Springer-Verlag.

Singh H.B.,Banaras Hindu University | Singh B.N.,Banaras Hindu University | Singh S.P.,Banaras Hindu University | Nautiyal C.S.,National Botanical Research Institute
Bioresource Technology | Year: 2010

Trichoderma harzianum NBRI-1055 was used, as fungal candidate to enhance the antioxidant activities of soybean matrix by modulating polyphenolic substances during solid-state fermentation. Trichoderma-fermented soybean (TFS) and unfermented soybean (UFS) products were extracted with water (W) and methanol (M). Total phenolic content of TFS-W and TFS-M extracts were significantly higher than that of UFS-W and UFS-M extracts. The effectiveness of extracts for total flavonoid content, antioxidant activity, free radical scavenging activity, reducing power, lipid peroxidation, metal ions-chelation, hydroxyl and superoxide radicals scavenging properties in descending order was TSF-W > TSF-M > USF-M> UFS-W. TFS extracts demonstrated significant protection against oxidative DNA and protein damages caused by hydroxyl radicals. For the specific phenolics profile, HPLC analysis was performed, which showed that the TFS extracts were also higher in isoflavones, flavonoids and phenolic acids, suggesting that this strategy may help to enhance TFS as potential antioxidants for use in preparation of soy food products. © 2010 Elsevier Ltd. All rights reserved.

Singh R.,Banaras Hindu University | Akhtar N.,Case Western Reserve University | Haqqi T.M.,Case Western Reserve University
Life Sciences | Year: 2010

A number of factors including inflammation and oxidative stress are believed to play a role in the development of chronic joint diseases. Green tea has become a popular drink and is consumed throughout the world. Extracts of green tea and polyphenols present therein have been shown to inhibit the inflammatory responses in vitro in different cell types and the development of arthritis in animal model studies. There is considerable evidence that (-)-epigallocatechin-3-gallate (EGCG), the predominant green tea polyphenol which mimic its effects, inhibits enzyme activities and signal transduction pathways that play important roles in inflammation and joint destruction in arthritis. After oral consumption EGCG become bioavailable and proteomic studies suggest that EGCG may directly interact with a large set of protein targets and alter the physiological response of the cells. Taken together these and other studies identify and support the use of EGCG as a possible chemopreventive agent with a potential to inhibit the development of arthritis. Here we review the biological effects of EGCG in an attempt to understand its pivotal molecular targets that directly affect the inflammation and joint destruction process for prevention and/or for the development of new therapeutics for arthritis in humans. © 2010 Elsevier Inc.

Ansari K.R.,Banaras Hindu University | Quraishi M.A.,Banaras Hindu University | Singh A.,Lovely Professional University
Measurement: Journal of the International Measurement Confederation | Year: 2015

The present paper deals with the adsorption and inhibitory effects of the pyridine derivatives, namely 2-amino-6-(2,4-dihydroxyphenyl)-4-(4-methoxyphenyl)nicotinonitrile (ADP) and 2-amino-4-(4-methoxyphenyl)-6-phenylnicotinonitrile (AMP) on N80 steel corrosion in 15% HCl. Among the studied compounds, ADP showed the inhibition efficiency of 90.24% at 200 mg/L. The corrosion study was performed by gravimetric, electrochemical impedance spectroscopy (EIS), Tafel polarization, scanning electron microscopy (SEM), scanning electrochemical microscopy (SECM) and energy-dispersive X-ray spectroscopy (EDX) techniques. The Langmuir isotherm model showed the best fit. The quantum chemical study was used to support the experimental results. 2015 Elsevier Ltd. All rights reserved.

Nandi G.C.,Banaras Hindu University | Singh M.S.,Banaras Hindu University | Ila H.,Jawaharlal Nehru Centre for Advanced Scientific Research | Junjappa H.,Institute of Management Sciences
European Journal of Organic Chemistry | Year: 2012

An efficient, highly regioselective protocol for the synthesis of the title compounds is reported. The reaction involves a one-pot, three-component cyclocondensation of β-oxodithioester, amine, and hydrazine in ethanol at reflux in the presence of a catalytic amount of acetic acid. Densely functionalized pyrazoles were constructed through the cyclization of a thioamide intermediate generated in situ from the β-oxodithioester. This method allows a rapid and general synthesis of previously inaccessible pyrazoles and synthetically demanding pyrazoles containing fused rings. A highly regioselective synthesis of the title compounds by one-pot, three-component cyclocondensation of β-oxodithioester, amine, and hydrazine in ethanol at reflux in the presence of a catalytic amount of acetic acid is reported. Densely functionalized pyrazoles were efficiently constructed through the cyclization of a thioamide intermediate that was generated in situ from the β-oxodithioester. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Singh A.K.,University of Lucknow | Siingh D.,Indian Institute of Tropical Meteorology | Singh R.P.,Banaras Hindu University
Atmospheric Environment | Year: 2011

The galactic cosmic rays (GCRs) originating from astrophysical sources and traversing through the interstellar/interplanetary medium reach the terrestrial atmosphere and produce complex dynamic changes in it. The flow rate of GCRs incident on the Earth's upper atmosphere is varied by the solar wind and the geomagnetic field. Striking correlations between the cloud cover and GCR fluxes on long time scale are observed whereas on short time scale no significant correlation is found. These observations are directly related to climate variations on short term as well as long term. In the present paper, we have reviewed and attempted to provide an overview of cosmic ray effects on terrestrial processes such as electrical phenomena, lightning discharges cloud formation and cloud coverage, temperature variation, space weather phenomena, Earth's climate and the effects of GCRs on human health. It is shown that CRs control long term variations of some of the above mentioned physical processes, which in turn control short term and long term variations in climate. It is also pointed out that there are many basic phenomena which need further study and require new and long term data set. © 2011 Elsevier Ltd.

Tiwari S.,Banaras Hindu University | Srivastava A.K.,Indian Institute of Tropical Meteorology | Singh A.K.,Banaras Hindu University
Atmospheric Environment | Year: 2013

Heterogeneity in aerosol characteristics was studied at five different locations over the Indo-Gangetic Basin (IGB) region during the pre-monsoon period (April-June 2011) using concurrent measurements from sun/sky radiometer, which is hypothesized to affect the Indian monsoon circulation and also the global climate system. Based on the measured aerosol products, distribution of aerosols and the associated optical properties were examined over the entire region. The pre-monsoon mean aerosol optical depth (AOD) was found to be maximum at Lahore (0.78) and Kanpur (0.68); however, a minimum AOD (~0.6) was observed at Karachi, Jaipur and Gandhi College, with relatively high variability at Karachi and low at Gandhi College. On the other hand, a significant gradient in Angstrom exponent (AE) from Karachi (0.30) in the west to Gandhi College (0.98) in the east IGB region suggests relative dominance of coarse particles over the western part and fine particles at the eastern part of the IGB. Results are confirmed with the aerosol size distribution and the air mass back-trajectory analysis at all the stations. The corresponding pre-monsoon mean single scattering albedo (SSA) shows relatively higher value at Karachi (0.94), suggests relative dominance of scattering type particles. On the other hand, lower SSA, ranging from 0.85 to 0.92, was observed at the other stations, with the lowest value at Gandhi College (0.85), which suggests absorbing aerosol distributions over the region. © 2013 Elsevier Ltd.

Kumar R.,Banaras Hindu University | Nylen S.,Karolinska Institutet
Frontiers in Immunology | Year: 2012

Visceral leishmaniasis (VL), commonly known as kala-azar, is caused by Leishmania donovani and Leishmania infantum (Leishmania chagasi in the Americas). These Leishmania species infect macrophages throughout the viscera, and parasites are typically found in the spleen, liver, and bone marrow. Patients with active disease typically exhibit marked immunosuppression, lack reactivity to the Leishmania skin test (LST), a delayed type hyper-sensitivity test, and their peripheral blood mononuclear cells (PBMC) fail to respond when stimulated with leishmanial antigens in vitro. However, most people infected with visceralizing species of Leishmania never develop disease. Understanding immune failure and the underlying immune mechanism that lead to disease as well as control of infection are key questions for research in this field. In this review, we discuss immunological events described in human and experimental VL and how these can affect the outcome of infection. © 2012 Kumar and Nylén.

Kumar S.,Radha Govind Engineering College | Rai S.B.,Banaras Hindu University
Indian Journal of Pure and Applied Physics | Year: 2010

Arginine molecule has been analyzed in parallel by infrared (IR) and Raman spectroscopy at room temperature. The vibrational spectra in the region 4000-400 cm-1 have been interpreted and band positions have been assigned tentatively, subsequently, a complete and complementry set of vibrational data has been obtained that can be used to determine several possible vibrational sets. In addition, electronic absorption spectrum of this molecule has been monitored at several pH value which reveals the effect of change of pH on peak shift.

Singh A.K.,University of Lucknow | Siingh D.,Indian Institute of Tropical Meteorology | Singh R.P.,Banaras Hindu University
Surveys in Geophysics | Year: 2010

The time varying conditions in the near-Earth space environment that may affect space-borne or ground-based technological systems and may endanger human health or life are referred to as space weather. Space weather effects arise from the dynamic and highly variable conditions in the geospace environment starting from explosive events on the Sun (solar flares), Coronal Mass Ejections near the Sun in the interplanetary medium, and various energetic effects in the magnetosphere-ionosphere-atmosphere system. As the utilization of space has become part of our everyday lives, and as our lives have become increasingly dependent on technological systems vulnerable to the space weather influences, the understanding and prediction of hazards posed by these active solar events have grown in importance. In this paper, we review the processes of the Sun-Earth interactions, the dynamic conditions within the magnetosphere, and the predictability of space weather effects on radio waves, satellites and ground-based technological systems today. © 2010 Springer Science+Business Media B.V.

Sudarshan M.,Banaras Hindu University | Weirather J.L.,University of Iowa | Wilson M.E.,University of Iowa | Sundar S.,Banaras Hindu University
Journal of Antimicrobial Chemotherapy | Year: 2011

Objectives: This study describes parasite kinetics in the blood of visceral leishmaniasis patients treated with liposomal amphotericin B (L-AmB) or a preformed fat emulsion of amphotericin B (ApL) using real-time quantitative PCR (qPCR). Methods: Forty-six patients were treated with a single dose (15 mg/kg of body weight) of either L-AmB (n=13) or ApL (n=33). qPCR was used to estimate parasite kinetics by detection of Leishmania donovani DNA using kinetoplast DNA-specific primers in peripheral blood samples using an absolute quantification method. Results: The mean parasite load decreased from baseline (day 0) values of 894.07 and 980.48 to 71.72 and 211.52 parasite genomes/mL at day 7 in L-AmB and ApL groups, respectively, and at day 30 these further declined to 8.30 and 133.98 parasite genomes/mL, respectively. At day 30 post-treatment evaluation, the decline in parasite load was significantly greater (P=0.024) with L-AmB compared with ApL. Four of 33 patients in the ApL group failed treatment (1 primary failure and 3 relapses) with the presence of parasites, whereas all patients in the L-AmB group were cured at 6 month follow-up. Conclusions: qPCR can be a tool to measure parasite dynamics accurately and provide a marker to measure the efficacy of various drugs. It can be used as a test of cure, allowing us to do away with invasive and risky methods such as splenic or bone marrow aspiration. © The Author 2011. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved.

Rastogi R.P.,Chulalongkorn University | Sinha R.P.,Banaras Hindu University | Incharoensakdi A.,Chulalongkorn University
Reviews in Environmental Science and Biotechnology | Year: 2014

The monocyclic heptapeptides microcystins (MCs), are a group of hepatotoxins, produced worldwide by some bloom-forming cyanobacterial species/strains both in marine and freshwater ecosystems. MCs are synthesized non-ribosomally by large multi-enzyme complexes consisting of different modules including polyketide synthases and non-ribosomal peptide synthetases, as well as several tailoring enzymes. More than 85 different variants of MCs have been reported to exist in nature. These are chemically stable, but undergo bio-degradation in natural water reservoirs. Direct or indirect intake of MCs through the food web is assumed to be a highly exposed route in risk assessment of cyanotoxins. MCs are the most commonly found cyanobacterial toxins that cause a major challenge for the production of safe drinking water and pose a serious threat to global public health as well as fundamental ecological processes due to their potential carcinogenicity. Here, we emphasize recent updates on different modes of action of their possible carcinogenicity. Besides the harmful effects on human and animals, MC producing cyanobacteria can also present a harmful effect on growth and development of agriculturally important plants. Overall, this review emphasizes the current understanding of MCs with their occurrence, geographical distribution, accumulation in the aquatic as well as terrestrial ecosystems, biosynthesis, climate-driven changes in their synthesis, stability and current aspects on its degradation, analysis, mode of action and their ecotoxicological effects. © 2014 Springer Science+Business Media Dordrecht.

Singh A.K.,Indian Institute of Toxicology Research | Tiwari M.N.,Indian Institute of Toxicology Research | Prakash O.,Banaras Hindu University | Singh M.P.,Indian Institute of Toxicology Research
Current Neuropharmacology | Year: 2012

Cypermethrin, a class II pyrethroid pesticide, is used to control insects in the household and agricultural fields. Despite beneficial roles, its uncontrolled and repetitive applications lead to unintended effects in non-target organisms. Cypermethrin crosses the blood-brain barrier and induces neurotoxicity and motor deficits. Cypermethrin prolongs the opening of sodium channel, a major site of its action, leading to hyper-excitation of the central nervous system. In addition to sodium channel, cypermethrin modulates chloride, voltage-gated calcium and potassium channels, alters the activity of glutamate and acetylcholine receptors and adenosine triphosphatases and induces DNA damage and oxidative stress in the neuronal cells. Cypermethrin also modulates the level of neurotransmitters, including gamma-aminobutyric acid and dopamine. It is one of the most commonly used pesticides in neurotoxicology research not only because of its variable responses depending upon the doses, time and routes of exposure and strain, age, gender and species of animals used across multiple studies but also owing to its ability to induce the nigrostriatal dopaminergic neurodegeneration. This article describes the effect of acute, chronic, developmental and adulthood exposures to cypermethrin in experimental animals. The article sheds light on cypermethrin-induced changes in the central nervous system, including its contribution in the onset of specific features, which are associated with the nigrostriatal dopaminergic neurodegeneration. Resemblances and dissimilarities of cypermethrin-induced nigrostriatal dopaminergic neurodegeneration with sporadic and chemicals-induced disease models along with its advantages and pitfalls are also discussed. © 2012 Bentham Science Publishers.

Nair R.R.,Banaras Hindu University | Khanna A.,Banaras Hindu University | Singh R.,Central Drug Research Institute | Singh K.,Banaras Hindu University
Fertility and Sterility | Year: 2013

Objective: To study the genetic association between methylenetetrahydrofolate reductase (MTHFR) A1298 polymorphism and recurrent pregnancy loss (RPL). Design: Prospective case-control study, systematic review, and meta-analysis using an electronic database up to July 27, 2012. Setting: Meta-analysis of four studies on RPL and three studies on spontaneously aborted embryos, including the present study. Patient(s): A total of 129 RPL patients and 202 healthy control women with successful pregnancy were analyzed including 40 spontaneously aborted embryos and 40 aborted embryos as control samples. For meta-analysis, 1,080 case and 709 control subjects were included of RPL and 375 case and 384 control samples of spontaneously aborted embryos. Intervention(s): Blood was collected by peripheral venous punctures, and spontaneously aborted embryos were collected by curettage or manual vacuum aspiration. Meta-analysis was done on the basis of heterogeneity of the studies. Main Outcome Measure(s): Genotyping was done by polymerase chain reaction (PCR)-restriction-fragment- length polymorphism (RFLP). DNA sequencing was used to ascertain PCR-RFLP results. Age-adjusted odds ratios were calculated by logistic regression analysis. Meta-analysis on this polymorphism was conducted to support our findings. Result(s): We found that presence of rare allele "C" and heterozygous and rare homozygous genotypes significantly increased the risk of RPL. No significant change in the fetal MTHFR A1298C genotype frequency was observed, regardless of chromosomal integrity. Meta-analysis of A1298C polymorphism on both RPL and in spontaneously aborted embryos showed significantly increased risk in the carriers of AC and CC genotypes. Conclusion(s): The data of the present study clearly suggests that MTHFR A1298C polymorphism is a genetic risk factor for pregnancy loss.

Gusain D.,Banaras Hindu University | Bux F.,Durban University of Technology | Sharma Y.C.,Banaras Hindu University
Journal of Molecular Liquids | Year: 2014

Application of nanocrystalline zirconia was investigated for the removal of chromium from aqueous solutions. The nanozirconia was synthesized by 'precipitation method'. The parameters namely initial concentration (5-65 ppm), pH (0.5 to 10.5), adsorbent dose (2 to 10 g/l) and temperature (298 K to 318 K) were optimized employing central composite design of response surface methodology. The removal of Cr was most affected by pH, followed by an initial concentration and adsorbent dose. Maximum removal (%) was achieved at an initial concentration of 20 ppm, pH = 3, adsorbent dose = 4 g/l and temperature 313 K. The experimental data were best fitted in Langmuir's isotherm equation and the removal followed pseudo second order kinetics. The mechanism of removal was explained by boundary layer diffusion via intraparticle diffusion and was further confirmed by Boyd plot. Thermodynamic parameters revealed that the removal process was spontaneous, endothermic and physiosorptive in nature. Adsorbent was regenerated with hydroxides (0.1 N NaOH, KOH and NH4OH) for further reuse. © 2014 Elsevier B.V.

Jena N.R.,Indian Institute of Information Technology, Design and Manufacturing | Mishra P.C.,Banaras Hindu University
Free Radical Biology and Medicine | Year: 2012

DNA damage by endogenous and exogenous agents is a serious concern, as the damaged products can affect genome integrity severely. Damage to DNA may arise from various factors such as DNA base modifications, strand break, inter- and intrastrand crosslinks, and DNA-protein crosslinks. Among these factors, DNA base modification is a common and important form of DNA damage that has been implicated in mutagenesis, carcinogenesis, and many other pathological conditions. Among the four DNA bases, guanine (G) has the smallest oxidation potential, because of which it is frequently modified by reactive species, giving rise to a plethora of lethal lesions. Similarly, 8-oxo-7,8-dihydroguanine (8-oxoG), an oxidatively damaged guanine lesion, also undergoes various degradation reactions giving rise to several mutagenic species. The various products formed from reactions of G or 8-oxoG with different reactive species are mainly 2,6-diamino-4-oxo-5-formamidopyrimidine, 2,5-diamino-4H-imidazolone, 2,2,4-triamino-5-(2H)-oxazolone, 5-guanidino-4-nitroimidazole, guanidinohydantoin, spiroiminodihydantoin, cyanuric acid, parabanic acid, oxaluric acid, and urea, among others. These products are formed from either ring opening or ring opening and subsequent rearrangement. The main aim of this review is to provide a comprehensive overview of various possible reactions and the mechanisms involved, after which these ring-opened and rearranged products of guanine would be formed in DNA. The biological significance of oxidatively damaged products of G is also discussed. © 2012 Elsevier Inc.

Shukla P.K.,Assam University | Mishra P.C.,Banaras Hindu University
International Journal of Quantum Chemistry | Year: 2013

The DNA base lesion spiroiminodihydantoin (Sp) is produced in biological systems endogenously and can cause mutation and cancer. It is considered to be more mutagenic and deleterious than 8-oxoguanine and other oxidized guanine products such as guanidinohydantoin (Gh) and imidazolone. In this work, the base pairing patterns of Sp with each of the normal nucleic acid bases of DNA have been investigated thoroughly using the B3LYP, M06-2X, and wB97X-D functionals of density functional theory in conjunction with the aug-cc-pVDZ basis set. It is found that the magnitudes of interaction energies between the bases and Sp follow the order: Sp-guanine >> Sp-cytosine > Sp-adenine > Sp-thymine. The strong Sp-guanine abnormal base pairing may be the main cause of the observed mutagenicity of Sp. © 2013 Wiley Periodicals, Inc. DNA in living organisms is attacked by reactive oxygen and nitrogen oxide species, free radicals, alkylating agents, and so forth, produced endogenously and exogenously, leading to diseases like cancer. Spiroiminodihydantoin (Sp) is formed due to the oxidation of guanine and 8-oxoguanine. This work investigates the base pairing patterns of Sp with each of the normal DNA bases and finds that the strong Sp-guanine abnormal base pairing may be the main cause of the observed mutagenicity of Sp. © 2013 Wiley Periodicals, Inc.

Kumar D.,Jawaharlal Nehru University | Yadav A.,Banaras Hindu University | Gaur J.P.,Banaras Hindu University
Aquatic Toxicology | Year: 2012

Prompted by the fact that interaction of metals with cyanobacterial mats has been little studied, the present study evaluates the response of a cyanobacterial mat, dominated by Phormidium bigranulatum, to elevated concentrations of Cd 2+ in the medium. The mat failed to grow at 7μM of Cd 2+ when the metal as also the mat inoculum were simultaneously added to the medium right in the beginning of the experiment due to marked sensitivity of P. bigranulatum, the main constituent of the mat, to high concentrations of Cd 2+. However, the mat previously grown in Cd 2+-free medium for a time period of 1-4 weeks grew successfully when exposed to media containing very high concentrations of Cd 2+. Four-week-old mat could grow at 250μM of Cd 2+, which has been found toxic to many cyanobacteria and algae by previous researchers. Greater tolerance of older mats to Cd 2+ may be due to greater proportion of exopolysaccharides, which are well known to sequester metal ions extracellularly, in them. Whereas the relative proportion of P. bigranulatum declined at high concentrations of the test metal that of green algae increased due most likely to their tolerance to Cd 2+. Air bubbles were seen entrapped in the mat due obviously to photosynthetic activity. Elevated concentrations of Cd 2+ reduced the number of air bubbles in the mat. Decline in number of air bubbles at high concentrations of metal ions was more prominent in the case of younger mat than in the older one. The present study also evaluated changes in species composition of mats of different age that were subsequently grown in Cd 2+ enriched culture medium. Younger mats showed change in species composition at very low concentrations of Cd 2+, but older mats showed little changes even at very high concentrations of the test metal. Hence older mats more strongly resisted to changes in its species composition than the younger ones upon exposure to high concentrations of Cd 2+. The growing mat successfully removed Cd 2+ from the medium, which was greater at lower concentrations of Cd 2+ in the external environment. © 2012 Elsevier B.V.

Singh S.K.,Banaras Hindu University | Drew M.G.B.,University of Reading | Singh N.,Banaras Hindu University
CrystEngComm | Year: 2013

New homoleptic complexes of the form [Ni(L)2] (L = L1 (dibenzyl dithiocarbamate) 1, L2 (N-benzyl-N,N-dimethyl ethylene dithiocarbamate) 2, and (R)2[Ni(L3)2)] (L 3 = p-chlorobenzene sulfonyl dithiocarbimate; R = (C 2H5)4N+3, (C3H 7)4N+4, (C6H13) 4N+5) have been prepared and characterized by elemental analyses, IR, 1H and 13C NMR and UV-visible absorption spectra. In addition, their structures have been elucidated by X-ray crystallography. The crystal structure of 1 reveals unusual C-H⋯Ni intermolecular anagostic interactions in axial positions resulting in 1D supramolecular chains, whereas complex salts 3 and 5 display unique C-H⋯Ni anagostic interactions due to the close proximity of one or two methylene protons in the cationic moieties to the Ni(ii) center of the [Ni(L3)2]2- complex anion, providing pseudo-square pyramidal and octahedral coordination environments respectively about the metal centers. To the best of our knowledge, 3 and 5 are the first examples of inter-ionic anagostic interactions within dithio complexes. Theoretical calculations have been performed for 3 and 5. The energy of interaction for 3 and 5 was found to be more than the previously reported neutral complexes. The supramolecular networks in all the complexes are sustained by non-conventional C-H⋯O, C-H⋯N and C-H⋯π (chelate, NiS2C) bonding interactions. All complexes are weakly conducting with σrt ∼10-6 S cm-1. © 2013 The Royal Society of Chemistry.

Rastogi R.P.,Chulalongkorn University | Sinha R.P.,Banaras Hindu University | Incharoensakdi A.,Chulalongkorn University
Chemosphere | Year: 2013

Scytonemin, located in the extracellular polysaccharide sheath of some cyanobacterial species is considered an efficient natural photoprotectant against lethal doses of ultraviolet (UV) radiations. In the present study, scytonemin from the cyanobacterium Rivularia sp. HKAR-4 was partially characterized and investigated for its induction by UV radiation as well as its role in photoprotection. High-performance liquid chromatography (HPLC) with photodiode-array detection studies revealed the presence of an UV-absorbing compound with absorption maximum at 386. nm. Based on its absorption spectrum and ion trap liquid chromatography/mass spectrometry (LC/MS) analysis, the compound was confirmed as scytonemin. In comparison to photosynthetically active radiation, a significant induction in the synthesis of scytonemin was found under UV-stress. Scytonemin also exhibited efficient photoprotective ability by detoxifying the in vivo reactive oxygen species (ROS) generated by UV radiation and by reducing the formation of thymine dimers. To the best of our knowledge this is the first report on the UV-screening effects of scytonemin on in vivo ROS generation and thymine dimer formation in any cyanobacterial strain. Based on these findings, we conclude that scytonemin may play a vital role in the survival and sustainability of cyanobacterial life in adverse environmental conditions such as under high solar irradiances. © 2013 Elsevier Ltd.

Srivastava A.K.,Aryabhatta Research Institute of Observational science ARIES | Dwivedi B.N.,Banaras Hindu University
Monthly Notices of the Royal Astronomical Society | Year: 2010

We study the intensity oscillations in the upper chromosphere/transition region (TR) and corona, above a bright point (BP) in the solar atmosphere. We analyse the time series of He ii 256 Å, Fe xii 195 Å and Fe xv 284 Å, observed in a 40-arcsec slot close to the centre of the Sun above the BP by the extreme ultraviolet (EUV) imaging spectrometer (EIS) on board Hinode. Using standard wavelet and periodogram tools, we produce power spectra of intensity oscillations. In the He ii 256.32 Å and Fe xii 195.12 Å EUV light curves, we detect intensity oscillations of the periods ∼ 263 ± 80 s and ∼ 241 ± 60 s, respectively, with a probability >95 per cent in wavelets, which are also consistent with their periodograms. This provides the most likely signature of the propagation of acoustic oscillations around the ∼5.0-min period from the photosphere to the inner corona. The radiative cooling and thus the finite radiative relaxation time are found to be the most likely mechanisms for the reduced cut-off frequency environment above the observed BP. This may allow the transfer of ∼5.0-min acoustic oscillations from the upper chromosphere/TR into the corona. We find that intensity oscillations in He ii 256.32 Å show temporal damping during the total span of the observation. This may be the first most likely observational signature of acoustic wave damping in the upper chromosphere caused by the radiative cooling effect. The intensity oscillations in Fe xii 195.12 Å show an amplification, which may be a most likely signature of the mode-coupling (two-wave interaction) and then resonant energy conversion, probably from transverse magnetohydrodynamic (MHD) waves of the double period (e.g. Alfvén waves) to the observed acoustic waves in the lower solar atmosphere where the plasma beta tends to unity. However, we find no evidence of real oscillations around the ∼5.0-min period with its amplification in the higher corona where the Fe xv 284.16 Å line is formed, which rules out this type of wave activity there. Almost 1.6 per cent of the solar surface is covered with small BPs, probably associated with the small-scale closed-loop system, which may be a subset of expanding flux tubes. Hence, the leakage of ∼5.0-min oscillations above such BPs, which is associated with the highest powers of strong convective motions, and probably resonantly amplified by transverse MHD waves (e.g. Alfvén waves), may be significant for heating the solar atmosphere locally. © 2010 The Authors. Journal compilation © 2010 RAS.

Sharma N.K.,Post Graduate College | Rai A.K.,Banaras Hindu University
Environmental Reviews | Year: 2011

The role of microbial diversity in ecosystem functioning is becoming increasingly recognized. Microalgae are a large group of organisms that are extremely diverse and heterogeneous from evolutionary and ecological viewpoints. However, estimates of their diversity are nebulous and require substantial input from systematics, dispersal analyses, and biogeography. Our generally poor understanding of microalgal biogeography has generated several hypotheses. According to one view, microalgae are cosmopolitan. However, use of advanced morphometric and molecular techniques suggest a restricted distribution (i.e., endemism) for many microalgae that were previously considered as cosmopolitan. The quest to have an exclusive theory of microalgal biogeography depends upon efforts to solve the problems related with appropriate taxonomic unit, genotype-morphospecies relationship, extent of synonymy in known species, degree of coexistence of endemic and cosmopolitan species, reasons for apparent restricted distribution, and the relative importance of sympatric speciation in genotype variations. This review discusses microalgal diversity from a biogeographical perspective, which, in turn, is analyzed in the light of empirical evidence available for the group. Also discussed are the arguments emerging from ongoing debates on the biogeography of other microorganisms. In addition to their immense ecological importance, microalgae have emerged as a potential source for a range of precious products including neutraceuticals, energy, and therapeutic drugs. Therefore, an understanding of their diversity and spatial distribution is crucial for formulating the conservation strategies for the group.

Srivastava A.K.,Aryabhatta Research Institute of Observational science ARIES | Dwivedi B.N.,Banaras Hindu University
New Astronomy | Year: 2010

We study intensity oscillations near the apex of a coronal loop to find the signature of MHD oscillations. We analyse the time series of the strongest Fe XII 195.12 Å image data, observed by 40″ SLOT of the EUV Imaging Spectrometer (EIS) onboard the Hinode spacecraft. Using a standard wavelet tool, we produce power spectra of intensity oscillations at location 'L3' near the apex of a clearly visible coronal loop. We detect intensity oscillations of a period of ≈322 s with a probability of 96%. This oscillation period of ≈322 s is found to be in good agreement with theory of the (second) harmonics of standing slow acoustic oscillations of P2 nd slow ≈ 313 ± 31 s. We detect, for the first time, the observational signature of multiple (first and second) harmonics of slow acoustic oscillations in the non-flaring coronal loop. Such oscillations have been observed in the past in hot and flaring coronal loops only, but have been predicted recently to exist in comparatively cooler and non-flaring coronal loops as well. We find the periodicities ∼497 s and ∼592 s with the probability 99-100% at the 'L1' and 'L2' locations, respectively, near the clearly visible western footpoint of the loop. We interpret these oscillations to be likely associated with the first harmonics (fundamental mode) of slow acoustic oscillations. Using the period ratios P1 / P2 = 1.54 and 1.84, we estimate the density scale heights in the EUV loop as ∼10 Mm and 21 Mm, respectively, in which the latter value (∼21 Mm) is compared well with the loop half length. We also find an evidence of propagating bright blob at its lower bound sub-sonic speed of ≈6.4 km/s, suggesting that they are caused by the mass flow from one end to the other in the coronal loop. We also suggest that standing oscillations, and propagating bright blobs caused probably by the pulse of plasma flow, co-exist in comparatively cooler and non-flaring coronal loop. © 2009 Elsevier B.V. All rights reserved.

Singh M.S.,Banaras Hindu University | Nandi G.C.,University of North Florida | Chanda T.,Banaras Hindu University
RSC Advances | Year: 2013

Utilization of the fascinating properties of β-oxodithioesters as building blocks in heterocyclic frameworks was started a few decades ago. Its similarity and dissimilarity with β-ketoesters in terms of its synthesis or as a substrate towards synthesis makes it an interesting and emerging field of synthetic organic chemistry. Tuning of catalysts and counter substrates towards selective utilization of its multiple reacting sites was summarized in the following discussion. A diverse range of monocyclic and polycyclic heterocycles with several different heteroatoms is plotted in an easy and reader friendly manner. This journal is © The Royal Society of Chemistry 2013.

Kumar M.,Banaras Hindu University | Srivastava A.K.,Aryabhatta Research Institute of Observational science ARIES | Dwivedi B.N.,Banaras Hindu University
Monthly Notices of the Royal Astronomical Society | Year: 2011

We analyse the temporal image data of the quiet Sun observed by the X-ray Telescope (XRT) onboard the Hinode spacecraft and Al-poly filter on 2007 March 31. We choose these temporal image data of ~30s cadence from 11:34:48 ut to 14:19:35 ut to study intensity oscillations above selected X-ray bright points (XBPs) with an exposure time 8.193s of each XRT image. Using the Fourier filtering method, we reconstruct X-ray light curves for the periods outside the cone-of-influence (COI) of their power spectrum. Using the standard wavelet software, we derive the power spectra of the reconstructed light curves which are generated by filtering the original X-ray time-series at the Fourier scale (54.55 min) outside the COI period (60.18 min) free from the edge effect and inappropriate long-term periodicities. This procedure provides statistically significant and globally distributed multiple periodicities in the intensity and global wavelet power spectra of the X-ray light curves derived from the selected coronal structures. We select seven XBPs to extract their respective X-ray light curves. We find the statistically significant observed periodicities (two or three) for XBP1, XBP2, XBP4, XBP5, XBP6 and XBP7, respectively, to be (28, 15) min, (50, 20) min, (60, 20, 12) min, (51, 23) min, (35, 23, 13) min, (49, 20) min and (35, 19) min. We interpret these observed periodicities in terms of the leakage of various harmonics of magnetoacoustic waves into the higher corona. Some BPs (XBP1, XBP3, XBP5 and XBP7) show the shift in the period ratio either as (P1/P2) < 2.0 or as (P1/P3)< 3.0. This period ratio shift provides the first most likely observational signature of the density stratification in these XBPs. Other BPs (XBP2, XBP4 and XBP6) show the shift in the period ratio (P1/P2) > 2.0, which may serve as evidence for magnetic field divergence with a significant effect on the various harmonics of magnetoacoustic waves. © 2011 The Authors Monthly Notices of the Royal Astronomical Society © 2011 RAS.

Pandey V.C.,CSIR - Central Electrochemical Research Institute | Bajpai O.,Banaras Hindu University | Singh N.,CSIR - Central Electrochemical Research Institute
Renewable and Sustainable Energy Reviews | Year: 2016

Phytoremediation is a holistic approach and can be used in large scale to remediate the contaminated land resources. Although the concept of phytoremediation is few decades old and has been applied on a wide range of pollutants, but their sustainability is still questioned at various scientific forums. Therefore, it is the need of the hour to remediate our valuable resources with due considerations for future generations. Such a synergistic bonding by using potential energy crops in phytoremediation programs would be useful to generate new bioenergy resources along with the remediation of contaminated soil. There are several energy crops in the world, but four promising and dedicated energy crops i.e. Miscanthus, Ricinus, Jatropha, Populus have primarily considered in this review to accomplish energy demands with their phytoremediation potential. These four energy crops also act as potential carbon sink and offer an additional profit as carbon tax credits. In recent time we have been able to improve our understanding in phytoremediation, but use of energy plants were not considered so far to make this venture socio-economically acceptable to the society. The present review provides a strategy for linking energy crops in phytoremediation to resolve the sustainability issues and effectively solve the challenges of ever increasing contaminated sites and biofuel demands now and for future. © 2015 Elsevier Ltd. All rights reserved.

Mishra R.,CSIR - Central Electrochemical Research Institute | Singh S.K.,CSIR - Central Electrochemical Research Institute | Singh S.K.,Banaras Hindu University
BMC Neuroscience | Year: 2014

Background: Human brain microvascular endothelial cells (hBMVECs) are integral part of the blood brain barrier. Post-translational modifications of adherens junction proteins regulate the permeability of human brain microvascular endothelial cells. Pro-inflammatory signals can induce tyrosine phosphorylation of adherens junction proteins. The primary objective of this work is to provide a molecular model; how the HIV-1 Tat protein can compromise the BBB integrity and eventually lead to neurological consequences. We exposed hBMVECs to recombinant HIV-1 clade C Tat protein to study the effect of HIV-1 Tat C on permeability of hBMVECs. Trans-endothelial electrical resistance and fluorescent dye migration assay have been used to check the permeability of hBMVECs. DCFDA staining has been used for intracellular reactive oxygen species (ROS) detection. Western blotting has been used to study the expression levels and co-immunoprecipitation has been used to study the interactions among adherens junction proteins.Results: HIV-1 Tat C protein induced NOX2 and NOX4 expression level and increased intracellular ROS level. Redox-sensitive kinase; PYK2 activation led to increased tyrosine phosphorylation of VE-cadherin and β-catenin, leading to disruption of junctional assembly. The dissociation of tyrosine phosphatases VE-PTP and SHP2 from cadherin complex resulted into increased tyrosine phosphorylation of VE-cadherin and β-catenin in HIV-1 Tat C treated hBMVECs.Conclusion: Unrestricted phosphorylation of junctional proteins in hBMVECs, in response to HIV-1 Tat C protein; leads to the disruption of junctional complexes and increased endothelial permeability. © 2014 Mishra and Singh; licensee BioMed Central Ltd.

Abhishek V.,Victoria Hospital | Avinash V.,Banaras Hindu University
Asian Cardiovascular and Thoracic Annals | Year: 2012

Hydatid disease is endemic to various regions of the world, with an incidence of 0.4 per 100,000 persons. Isolated cardiac involvement is rare and occurs in only 0.02%-2% of cases. As the majority of cases are asymptomatic, can present catastrophically, and lead to high mortality, it has become increasingly important to identify the disease in an early stage and treat it with surgical excision. This review aims to familiarize the readers with the varied presentations, early diagnosis, and management of cardiac hydatid disease. © The Author(s) 2012.

Anjum S.,Banaras Hindu University | Krishna A.,Banaras Hindu University | Tsutsui K.,Waseda University
Journal of Endocrinology | Year: 2014

The aim of this study was to evaluate the effects of in vivo and in vitro treatments with RFamide-related peptide 3 (RFRP3), a mammalian gonadotropin-inhibitory hormone ortholog, on testicular activities, i.e. spermatogenesis and steroidogenesis, in mice. Mice were treated in vivo with different doses of RFRP3 (control: 0.02 μg, 0.2 μg, and 2.0 μg/day) for 8 days. For in vitro study, the testes of mice were evaluated with different doses of RFRP3 (control: 1 and 10 ng/ml) with or without LH (control: 10 and 100 ng/ml) for 24 h at 37 °C. RFRP3 treatment produced significant changes in the body mass, circulating steroid level, and testicular activity in mice. RFRP3 treatment also caused dose-dependent histological changes in spermatogenesis, such as decline in germ cell proliferation and survival markers and increase in apoptotic markers in testis. Both in vivo and in vitro studies showed the inhibitory effect of RFRP3 on testosterone synthesis in the testis. RFRP3 inhibited the expression of the receptor for LH (LHCGR), STAR protein, cytochrome P450 side-chain cleavage (CYP11A1) and 3ß-hydroxysteroid dehydrogenase in the testis, and testosterone secretion dose dependently. This study also suggested that the inhibitory effect of RFRP3 in the testis may be mediated through local production of GnRH. Thus, RFRP3 inhibits testicular steroidogenesis and spermatogenesis either indirectly through GnRH or by directly influencing germ cell proliferation, survival, and apoptosis. © 2014 Society for Endocrinology.

Chawla R.,Banaras Hindu University | Jaiswal S.,CSIR - Central Electrochemical Research Institute | Mishra B.,Banaras Hindu University
Expert Opinion on Drug Delivery | Year: 2014

Objective: The objective of the present study was to develop sustained release biodegradable polymeric nanoparticles (PNs) of two anti-tubercular drugs (ATDs), rifampicin (RIF) and isoniazid (INH) using circumscribed central composite factorial design (CCD) and evaluate in vivo uptake potential using rhodamine labeled PNs (RPNs). Methods: CCD was employed to study the influence of independent formulation factors, drug:polymer ratio (D:P) and surfactant concentration (SC), on dependent physicochemical characteristics, particle size (PS), polydispersity index (PI) and percentage entrapment efficiency (%EE) of the drugs. Optimized PNs prepared using response surface methodology (RSM) were evaluated for in vitro kinetics at endosomal macrophage pH 5.2 and physiological pH 7.4 and in vivo targeting potential in peritoneal macrophages (PMs) by fluorescence microscopy (FM) and confocal laser scanning microscopy (CLSM). Results: Optimized PNs exhibited spherical and porous surface with a mean PS of 202 nm, PI of 0.178, zeta potential of -25.49 mV and %EE of 76.12% and 54.25% for RIF and INH, respectively. Conclusions: Highly hydrophilic INH could be encapsulated with lypophilic RIF with efficiency. In vivo uptake studies of RPNs in PMs suggested endocytosis of RPNs without any surface adsorption phenomenon. Hence, further studies need to be performed for establishing the pharmacokinetic potential of PNs. © 2014 Informa UK, Ltd.

Dhillon G.S.,University of Québec | Brar S.K.,University of Québec | Kaur S.,Banaras Hindu University | Verma M.,Institute de Recherche et de Developpement en Agroenvironnement Inc. IRDA
Critical Reviews in Biotechnology | Year: 2012

In recent years, the green approach of nanoparticle synthesis by biological entities has been gaining great interest over various other physico-chemical methods, which are laden with many disadvantages. The important challenging issues in current nanotechnology include the development of reliable experimental techniques for the synthesis of nanoparticles of different compositions and sizes along with high monodispersity. Biological systems offer unique promising features to tailor nanomaterials with predefined properties. Fungi are the favorite choice of microorganisms due to the wide variety of advantages they offer over bacteria, yeast, actinomycetes, plants, and other physico-chemical techniques. The use of microorganisms for the deliberate synthesis of nanoparticles is a fairly new and exciting area of research with considerable potential for further development. This review describes an overview of the current green approaches for the synthesis of nanoparticles with particular emphasis on fungi, which are gaining worldwide popularity as nano-factories for the green synthesis of nanoparticles. © 2012 Informa Healthcare USA, Inc.

Sharma N.,CSIR - Central Electrochemical Research Institute | Singh S.K.,Banaras Hindu University
Reviews in Medical Virology | Year: 2016

The advances in RNA sequencing have unveiled various non-coding RNAs (ncRNAs), which modulate the gene expression. ncRNAs do not get translated into proteins. These include transfer RNAs, ribosomal RNAs, microRNA (miRNA), short interfering RNA, long non-coding RNA, piwi-interacting RNA and small nuclear RNA. ncRNAs regulate gene expression at various levels and control cellular machinery. miRNAs have been reported in plants, animals, several invertebrates and viruses. The miRNAs regulate the gene expression post-transcriptionally. Viral infection strongly influences the abundance and the distribution of miRNAs and other ncRNAs within the host cells. Viruses may encode their own miRNA, which help in the viral life cycle and other aspects of pathogenesis. Viruses are known to successfully modulate the expression pattern of ncRNAs. The ncRNA-based strategies adopted by viruses for their survival present a complex picture of host–virus interactions. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Saxena P.K.,Jaypee Institute of Information Technology | Saxena P.K.,Banaras Hindu University
Infrared Physics and Technology | Year: 2011

In the present paper the performance of p+-n-n+ Hg1-xCdxTe long wavelength infrared (LWIR) homojunction photodetector (x ≈ 0.22) has been analyzed theoretically and simulated numerically using ATLAS software from SILVACO®. The results obtained in the two cases are compared and contrasted with the available experimental results. The energy band diagram, electric field profile, carrier concentration, dark current, dynamic resistance, quantum efficiency and detectivity have been calculated and optimized as a function of different variables such as device thickness, reverse voltage and operating wavelength in order to optimize the performance of p+-n-n+ photodetector at 77 K. The dependence of the p+-n junction position within homostructure on bandgap energy profiles and the influence of doping concentration on photodetector parameters have been studied. In the present model the Johnson-Nyquist and shot noise have been considered in calculation of detectivity. Results of our study reveal that under suitable biasing conditions the photodetector exhibits a dark current, ID ≈ 10-7 A, and a zero bias resistance, R0 = 106 Ω and a detectivity 8 × 109 mHz1/2/W. © 2010 Elsevier B.V. All rights reserved.

Venkateshwarlu M.,CSIR - Central Electrochemical Research Institute | Chalapathi Rao N.V.,Banaras Hindu University
Precambrian Research | Year: 2013

New palaeomagnetic and rock magnetic results are reported for 1.1Ga Mesoproterozoic kimberlites from the distinct fields of Wajrakarur (WKF), Narayanpet (NKF) and Raichur (RKF) occurring within the Eastern Dharwar craton, southern India. In all, 35 oriented block samples were collected from ten kimberlite pipes and our results constitute first of their kind for the kimberlites from NKF and RKF. Palaeomagnetic data reveal that characteristic remanent magnetization (ChRM) directions of the studied kimberlites show a mean declination of 39 and mean inclination of -16 (N=4, k=37.6 and α95=15.2) and yield a virtual geomagnetic pole at 44.5°N, 195.4°E (dp=8.0, dm=15.6). This new pole position is identical to the earlier reported palaeomagnetic pole that lies at 36.8°N, 212.5°E for some Wajrakarur kimberlites and other such global results at 1100Ma from Umkondo dolerites, Kalahari craton, southern Africa. The newly obtained palaeomagnetic pole also correlates well with the virtual geomagnetic pole (VGP) generated from the 1.1Ga Majhgawan kimberlite, Mahoba dyke and the Bhander-Rewa sedimentary Group in the Upper Vindhyan sequence within the Bundelkhand craton of Northern India. Our results support a Mesoproterozoic closure age of the upper sedimentary horizons for the 'Purana' sedimentary basins and provide evidence for accretion of the northern and southern Indian cratonic blocks prior to 1.1Ga. Our study also demonstrates that in ~1.1Ga palaeomagnetically based Rodinia reconstructions, India occupies a lower palaeolatitudinal position, was much separated from Australia and that East Gondwana very likely did not form an assembly until the terminal Neoproterozoic. © 2012 Elsevier B.V..

Dhillon G.S.,University of Québec | Kaur S.,Banaras Hindu University | Brar S.K.,University of Québec | Verma M.,Institute de Recherche et de Developpement en Agroenvironnement Inc. IRDA
Critical Reviews in Biotechnology | Year: 2013

Chitosan, copolymer of glucosamine and N-acetyl glucosamine is mainly derived from chitin, which is present in cell walls of crustaceans and some other microorganisms, such as fungi. Chitosan is emerging as an important biopolymer having a broad range of applications in different fields. On a commercial scale, chitosan is mainly obtained from crustacean shells rather than from the fungal sources. The methods used for extraction of chitosan are laden with many disadvantages. Alternative options of producing chitosan from fungal biomass exist, in fact with superior physico-chemical properties. Researchers around the globe are attempting to commercialize chitosan production and extraction from fungal sources. Chitosan extracted from fungal sources has the potential to completely replace crustacean-derived chitosan. In this context, the present review discusses the potential of fungal biomass resulting from various biotechnological industries or grown on negative/low cost agricultural and industrial wastes and their by-products as an inexpensive source of chitosan. Biologically derived fungal chitosan offers promising advantages over the chitosan obtained from crustacean shells with respect to different physico-chemical attributes. The different aspects of fungal chitosan extraction methods and various parameters having an effect on the yield of chitosan are discussed in detail. This review also deals with essential attributes of chitosan for high value-added applications in different fields. © 2013 Informa Healthcare USA, Inc.

Kaur J.,CSIR - Central Electrochemical Research Institute | Sundar S.,Banaras Hindu University | Singh N.,CSIR - Central Electrochemical Research Institute
Journal of Antimicrobial Chemotherapy | Year: 2010

Objectives: Using the pteridine reductase (PTR1) enzyme of Leishmania as the target, the objective of our study was to find a drug candidate that can enter the clinical development process after being evaluated for safety and efficacy in animals. Methods: Monastrol (R) and (S) enantiomers were docked using the QUANTUM program into the active site of a Leishmania donovani PTR1 (LdPTR1) homology model. A structure-activity relationship based on a homology model of a recombinant enzyme was substantiated by a recombinant enzyme inhibition assay. We adapted an L. donovani (transfected with green fluorescent protein) intramacrophage amastigote screening assay as a cellular model for leishmaniasis. Furthermore, since the clinicopathological features and immunopathological mechanisms of visceral leishmaniasis (VL) in a hamster model are remarkably similar to those of human disease, systemic infection of hamsters with L. donovani was utilized to collect in vivo data for monastrol. Results: Both monastrol (R) and (S) enantiomers fit well in the ligand-binding pocket of LdPTR1. Monastrol exhibits a Ki value of 0.428 μM in the recombinant enzyme inhibition assay. We confirm monastrol as a potent inhibitor of PTR1 in Leishmania; it inhibits proliferation of amastigotes with an IC50 (50% inhibitory concentration) of 10 μM in macrophage cultures infected with an L. donovani clinical isolate, with no host cytotoxicity. We also show that in experimental animals, oral administration of a 5 mg/kg dose of monastrol on two alternate days inhibits 50% of parasite growth, giving therapeutic backing to the use of monastrol as a potent antileishmanial in human VL cases. Conclusions: To our knowledge, this is the first report presenting monastrol as a potent oral antileishmanial. © The Author 2010.

Madhu D.,Banaras Hindu University | Singh B.,Central University of Jharkhand | Sharma Y.C.,Banaras Hindu University
RSC Advances | Year: 2014

A low cost raw material obtained from the discarded parts of fish (Cirrhinus mrigala, Cirrhinus cirrhosa, Cirrhinus reba) was utilized as feedstock oil and catalyst for the synthesis of biodiesel. Esterification followed by transesterification was carried out for the synthesis of biodiesel from waste fish oil. The discarded parts of fish after extraction of oil that included fins, tails and bones were used to derive a low cost heterogeneous catalyst for the synthesis of biodiesel. The catalyst characterized by thermo-gravimetric analysis and X-ray diffraction analysis showed the calcination temperature required and the phase of the catalyst respectively. The HAP (hydroxyapatite) present in the waste parts of fish was converted into β-tri-calcium phosphate when calcined at 900 °C for 2 h. The catalyst, β-tri-calcium phosphate was studied for its morphology and porous structure by scanning electron microscopy. A moderate experimental condition (1 : 6.5 molar ratio of oil : methanol, 1.5 wt% of heterogeneous catalyst with respect to oil) was taken for synthesis of biodiesel from waste fish oil. Biodiesel characterized by proton NMR showed a high conversion of waste fish oil to biodiesel (i.e. >96%). The yield of biodiesel determined by gravimetric method was >95%. The heterogeneous catalyst, β-tri-calcium phosphate was reused up to five times without significant loss in its activity. This journal is © the Partner Organisations 2014.

Selvamani S.P.,CSIR - Central Electrochemical Research Institute | Mishra R.,CSIR - Central Electrochemical Research Institute | Singh S.K.,CSIR - Central Electrochemical Research Institute | Singh S.K.,Banaras Hindu University
PLoS ONE | Year: 2014

Objectives: Chikungunya virus causes chronic infection with manifestations of joint pain. Human synovial fibroblasts get infected with CHIKV and could lead to pro-inflammatory responses. MicroRNAs have potentials to regulate the gene expression of various anti-viral and pro-inflammatory genes. The study aims to investigate the role of miR-146a in modulation of inflammatory responses of human synovial fibroblasts by Chikungunya virus. Methods: To study the role of miR-146a in CHIKV pathogenesis in human synovial cells and underlying inflammatory manifestations, we performed CHIKV infection in primary human synovial fibroblasts. Western blotting, real-time PCR, luciferase reporter assay, overexpression and knockdown of cellular miR-146a strategies have been employed to validate the role of miR-146a in regulation of pro-inflammatory NF-κB pathway. Results: CHIKV infection induced the expression of cellular miR-146a, which resulted into down-regulation of TRAF6, IRAK1, IRAK2 and increased replication of CHIKV in human synovial fibroblasts. Exogenous expression of miR-146a in human synovial fibroblasts led to decreased expression of TRAF6, IRAK1, IRAK2 and decreased replication of CHIKV. Inhibition of cellular miR-146a by anti-miR-146a restored the expression levels of TRAF6, IRAK1 and IRAK2. Downregulation of TRAF6, IRAK1 and IRAK2 led to downstream decreased NF-κB activation through negative feedback loop. Conclusion: This study demonstrated the mechanism of exploitation of cellular miR-146a by CHIKV in modulating the host antiviral immune response in primary human synovial fibroblasts. © 2014 Selvamani et al.

Rao N.V.C.,Banaras Hindu University | Kamde G.,Rashtrasant Tukadoji Maharaj Nagpur University | Kale H.S.,Rashtrasant Tukadoji Maharaj Nagpur University | Dongre A.,Institute of Science
Precambrian Research | Year: 2010

Petrology and geochemistry of eleven Mesoproterozoic lamproites from the Krishna valley, Eastern Dharwar craton, are presented. The Krishna lamproites show wide variation in their petrography and modal mineralogy and constitute excellent examples of rare phenomenon of heteromorphism. Ti-phlogopite, clinopyroxene, richterite, Fe-rich sanidine, sphene, F-rich apatite, ilmenite, and rutile are the major minerals present in varying proportions. Their mineral compositions overlap with those present in world-wide Phanerozoic lamproites and casts doubt on recent suggestions regarding the absence of archetypal lamproites and kimberlites from the Indian cratons. Incompatible trace element ratios (i) rule out the Krishna lamproites to be products of direct plume- (asthenospheric) derived mantle as well as subduction-related components and (ii) demonstrate their derivation from sources similar to those of the co-spatial Cuddapah basin lamproites and Wajrakarur- and Narayanpet-kimberlites from the Eastern Dharwar craton. The source enrichment of the Krishna lamproites is related to the period of global-scale mantle upwelling at ∼1.9 Ga that included the emplacement of Large igneous provinces of similar age and magmatism in the Dharwar and Bastar cratons (India), the Superior Craton (Canada) and the Kaapvaal craton (southern Africa). We find that the observed petrological and geochemical characteristics of the Krishna lamproites can be best explained by the vein-plus-wall-rock model involving phlogopite + amphibole + rutile + clinopyroxene + apatite + titanite occuring as metasomatic veins in a depleted lithospheric mantle, within the garnet stability field. Our study illustrates the significant role of the lithospheric thickness and its attendant metasomatism in influencing petrogenesis of the co-spatial Mesoproterozoic lamproites and kimberlites from the Eastern Dharwar craton. © 2009 Elsevier B.V. All rights reserved.

Singh P.,Banaras Hindu University | Krishna A.,Banaras Hindu University | Tsutsui K.,Waseda University
Fertility and Sterility | Year: 2011

Objective: To evaluate the effects of gonadotropin-inhibitory hormone (GnIH) treatment on ovarian activity of mice. Design: Animal study. Setting: Reproductive physiology laboratory of university department of zoology. Animal(s): Twelve-week-old female mice of inbred Parkes strain. Intervention(s): Mice treated with different doses of GnIH (control, 100 ng, 500 ng, and 2 μg per day) for 8 days were studied. For in vitro study, the ovaries of proestrus mice were cultured with different doses of GnIH for 24 hours at 37°C. Main Outcome Measure(s): Folliculogenesis, steroidogenesis, luteogenesis, and apoptosis in the ovaries of control and GnIH-treated mice. Result(s): GnIH treatment produced significant changes in body mass, circulating steroid levels, and ovarian activity in the mice. GnIH also caused dose-dependent histologic changes in follicular development and luteinization. The antral follicles showed abnormal changes. The mice treated with increasing dose of GnIH showed significant changes in steroid synthesis owing to inhibitory effects of GnIH on ovarian expression of LH receptor, steroidogenic acute regulatory, and 3β-hydroxysteroid dehydrogenase proteins. Conclusion(s): GnIH inhibited follicular development and steroidogenesis in the ovary of mice. This study thus suggests biologic significance of this neuropeptide in regulating ovarian activity. © 2011 American Society for Reproductive Medicine, Published by Elsevier Inc.

Singh A.K.,Banaras Hindu University | Singh A.K.,National Autonomous University of Mexico | Singh S.K.,Banaras Hindu University | Rai S.B.,Banaras Hindu University
RSC Advances | Year: 2014

Lanthanide based materials are preferred over other luminescent materials for various applications. Current focus in this area is to exploit the unique luminescence features of lanthanide-based materials for multidisciplinary research and novel applications. Furthermore, efforts are going on to enhance the luminescence of lanthanide ions for better performance. In a broader sense, there are two ways to enhance the luminescence of lanthanide ions. The first is to use a suitable sensitizer, which can absorb excitation energy efficiently, and can transfer it to the lanthanide ions. This method has been known for a long time and is well documented in the literature. The second way is to modify host matrices in such a way that it favors radiative transitions. It is widely reported in the literature that the presence of alkali ions, particularly Li+ ions, in a matrix enhances the luminescence of lanthanide ions significantly. But there are no comprehensive reports available in the literature that summarize how alkali ions help in the luminescence enhancement of lanthanide ions in various host matrices. The prime objective of this review is to highlight various contributing factors that help in the luminescence enhancement of lanthanide ions in the presence of alkali ions. This journal is © the Partner Organisations 2014.

Tyagi R.,Nanjing University of Science and Technology | Tyagi R.,Banaras Hindu University | Xiong D.,Nanjing University of Science and Technology | Li J.,Nanjing University of Science and Technology
Wear | Year: 2011

Sliding wear of behavior of Ni-based composites, prepared by powder metallurgy route and containing different (0, 8, 12, 16 and 20. wt.%) amounts of silver, was investigated under different loads and speeds by conducting wear tests against a counterface of AISI 52100 ring using a ring-on-disk set up. One composite containing 12. wt.% silver and 4. wt.% h-BN was also prepared and tested under same conditions to investigate the synergistic action of Ag and h-BN. The friction coefficients and the wear rates are significantly reduced by addition of silver and h-BN. The friction coefficient reduced from 0.36 to 0.21 by addition of solid lubricants whereas the reduction was 3-5 times in the wear rates. The friction coefficients of composites decreased with increasing load and sliding speed whereas the wear rates increased marginally. No noticeable synergy could be observed between silver and h-BN because h-BN fails to form strongly adherent transfer film on counterface surface. © 2010 Elsevier B.V.

Geed M.,Banaras Hindu University | Garabadu D.,Banaras Hindu University | Ahmad A.,Amity University | Krishnamurthy S.,Banaras Hindu University
Pharmacology Biochemistry and Behavior | Year: 2014

Silymarin commonly known for its hepatoprotective effect is reported to show protection against 6-hydroxydopamine-induced neurotoxicity. Silibinin forms the major active constituent of silymarin. Therefore, the neuroprotective effect of silibinin (50, 100 and 200 mg/kg) was evaluated in the unilaterally injected 1-methyl-4-phenylpyridinium (MPP+)-induced dopaminergic neurotoxicity in male rats. A battery of tests such as elevated plus maze (EPM), narrow beam walk, open field, bar catalepsy, grip strength, and foot print analysis was performed to evaluate the behavioral symptoms of striatal dopaminergic toxicity. Furthermore, the mechanism of action of silibinin was investigated by evaluating the mitochondrial complex enzyme activities, mitochondrial integrity and oxidative status. Striatal caspase-3 and NFκB were expressed to evaluate the effect of silibinin on apoptosis and inflammation respectively. Silibinin (100 and 200 mg/kg) protected against MPP +-induced dopamine depletion in striatum. Silibinin reversed MPP +-induced decrease in transfer latency indicating memory consolidation in the EPM test. Silibinin (100 and 200 mg/kg) attenuated MPP +-induced motor deficits, such as fine motor movements and gait. MPP+-induced mitochondrial dysfunction, loss of integrity and oxidative stress were attenuated by silibinin. Silibinin decreased striatal caspase-3 and NFκB expression indicating potential anti-apoptotic and anti-inflammatory effects respectively. Hence, silibinin exhibited neuroprotective effect in the MPP+ induced striatal toxicity augmenting dopamine levels. The mechanism of action may be linked to maintenance of mitochondrial bioenergetics and integrity apart from anti-apoptotic and anti-inflammatory activities. © 2013 Elsevier Inc.

Singh S.,Sanjay Gandhi Post Graduate Institute of Medical Sciences | Rai G.,Banaras Hindu University | Aggarwal A.,Sanjay Gandhi Post Graduate Institute of Medical Sciences
Rheumatology International | Year: 2014

MicroRNAs (miRNAs) are non-coding RNA that modulate the expression of multiple target genes at the post-transcriptional level. Single-nucleotide polymorphisms (SNPs) in pre-miRNAs can alter miRNA expression, and polymorphism in target molecules can affect binding to target mRNA. Studies have shown an association between miR-146a gene polymorphism and autoimmune diseases. A target for miR-146a is IRAK1. We studied the SNPs of miRNA-146 and IRAK1 to see their association with susceptibility to juvenile idiopathic arthritis–enthesitis-related arthritis (JIA-ERA). One hundred and fifty patients with JIA-ERA (ILAR criteria) were included in the study. A total of 216 blood donors (201 male) with a mean age of 30.5 years served as controls. miR-146a (rs2910164) and its target IRAK1 (rs1059703) at exon-12 region and IRAK1 (rs3027898) at 3′UTR polymorphisms were analyzed using PCR-RFLP method. Among 150 patients, 133 were males and the mean age at onset of disease was 11 (4–16) years, mean disease duration was 4.5 (0.3–12) years. Twenty-two had uveitis and 21 had positive family history of spondyloarthropathy, 73 had enthesitis, 75 had inflammatory back pain, and all had arthritis. HLA B27 was present in 116 patients. Genotype frequency of miR-146a gene was in Hardy–Weinberg equilibrium in healthy controls. The genotype frequency for miR-146a was different in controls and patients [GG (51.85 vs. 50.0 %), GC (42.13 vs. 37.29 %) and CC (6.02 vs. 12.71 %), OR = 2.18; 95 % CI 1.02–4.68; p value = 0.0418]. The allele frequencies of IRAK1 (rs1059703) and IRAK1 (rs3027898) in males and genotype frequency in females were similar in controls and patients. The C allele of IRAK1 (rs1059703) was in linkage disequilibrium with T allele of IRAK1 (rs3027898). The CC genotype of the miR-146a rs2910164 polymorphism was significantly associated with the susceptibility to JIA-ERA. © 2014, Springer-Verlag Berlin Heidelberg.

Das M.,Indian Institute of Technology Guwahati | Saudagar P.,Indian Institute of Technology Guwahati | Sundar S.,Banaras Hindu University | Dubey V.K.,Indian Institute of Technology Guwahati
FEBS Journal | Year: 2013

Resistance of Leishmania parasites to miltefosine, which is only available oral drug, is a great concern. We have analyzed global gene expression profiles of miltefosine-unresponsive and miltefosine-responsive Leishmania donovani in order to understand the various metabolic processes involved in miltefosine drug resistance. The microarray data clearly indicated a role of oxidative metabolism in miltefosine resistance. Furthermore, fluorescence microscopy experiments suggested that miltefosine-unresponsive L. donovani resists the accumulation of reactive oxygen species and subsequent mitochondrial membrane damage leading to apoptotic death. In contrast, in miltefosine-responsive L. donovani, the accumulation of reactive oxygen species causes apoptotic death. Overall, this study provides fundamental insights into miltefosine resistance in L. donovani. Database The microarray data have been deposited in the Gene Expression Omnibus database under the accession number GSE45496 We have analyzed global gene expression profiles of miltefosine-unresponsive and miltefosine-responsive Leishmania donovani in order to understand various metabolic processes involved in miltefosine drug resistance. The microarray data clearly indicated a role of oxidative metabolism in miltefosine resistance. The experimental data supports that the miltefosine unresponsive Leishmania donovani can resists formation of reactive oxygen species more efficiently. © 2013 FEBS.

Singh S.K.,Banaras Hindu University | Singh M.K.,University of Aveiro | Nayak M.K.,Banaras Hindu University | Kumari S.,Banaras Hindu University | And 3 more authors.
ACS Nano | Year: 2011

Graphene oxide (GO), the new two-dimensional carbon nanomaterial, is extensively investigated for potential biomedical applications. Thus, it is pertinent to critically evaluate its untoward effects on physiology of tissue systems including blood platelets, the cells responsible for maintenance of hemostasis and thrombus formation. Here we report for the first time that atomically thin GO sheets elicited strong aggregatory response in platelets through activation of Src kinases and release of calcium from intracellular stores. Compounding this, intravenous administration of GO was found to induce extensive pulmonary thromboembolism in mice. Prothrombotic character of GO was dependent on surface charge distribution as reduced GO (RGO) was significantly less effective in aggregating platelets. Our findings raise a concern on putative biomedical applications of GO in the form of diagnostic and therapeutic tools where its prothrombotic property should be carefully investigated. © 2011 American Chemical Society.

Tiwari S.C.,Banaras Hindu University | Tiwari S.C.,Institute of Natural Philosophy
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2013

The geometric approach based on parallel transport and Wilson lines to gain insight into the decomposition of the gluon gauge 4-vector potential is being developed in the literature to address the proton spin puzzle. Unfortunately, conflicting claims on the uniqueness of the decomposition have been made. We reexamine this controversy and argue that Hodge decomposition and the de Rham theorem resolve this issue in a natural way such that the topological defects acquire a fundamental significance. It is suggested that qualitatively angular momentum holonomy could be an alternative new mechanism to account for the deficit proton spin. © 2013 American Physical Society.

Joshi C.,University of Delhi | Dwivedi A.,Banaras Hindu University | Rai S.B.,Banaras Hindu University
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2014

Infrared-to-visible upconverting rare earths Er3+/Yb 3+ co-doped Y2O3 nano-crystalline phosphor samples have been prepared by solution combustion method followed by post-heat treatment at higher temperatures. A slight increase in average crystallite size has been found on calcinations verified by X-ray analysis. Transmission electron microscopy (TEM) confirms the nano-crystalline nature of the as-prepared and calcinated samples. Fourier transform infrared (FTIR) analysis shows the structural changes in as-prepared and calcinated samples. Upconversion and downconversion emission recorded using 976 and 532 nm laser sources clearly demonstrates a better luminescence properties in the calcinated samples as compared to as-prepared sample. Upconversion emission has been quantified in terms of standard chromaticity diagram (CIE) showing a shift in overall upconversion emission of as-prepared and calcinated samples. Temperature sensing behaviour of this material has also been investigated by measurement of fluorescence intensity ratio (FIR) of various signals in green emission in the temperature range of 315 to 555 K under 976 nm laser excitation. © 2014 Elsevier B.V. All rights reserved.

Verma A.K.,University of Delhi | Joshi M.,University of Delhi | Singh V.P.,Banaras Hindu University
Organic Letters | Year: 2011

The regio- and stereoselective addition of N-heterocycles to alkynes using KOH is reported. Formation of (Z)-isomers and their conversion to (E)-products were found to be dependent upon time as well as the choice of base. Selective attack of N-heterocycles on a more electrophilic alkynyl carbon was supported by DFT calculations, and the stereochemistry of the products was established by X-ray crystallographic studies and intramolecular cyclization of ortho-haloalkynes in indolo-[2,1-a]isoquinolines. © 2011 American Chemical Society.

Kishore D.,Banaras Hindu University | Kundu S.,University of Delhi | Kayastha A.M.,Banaras Hindu University
PLoS ONE | Year: 2012

Background: In this case study, we analysed the properties of unfolded states and pathways leading to complete denaturation of a multimeric chick pea β-galactosidase (CpGAL), as obtained from treatment with guanidium hydrochloride, urea, elevated temperature and extreme pH. Methodology/Principal Findings: CpGAL, a heterodimeric protein with native molecular mass of 85 kDa, belongs to α+β class of protein. The conformational stability and thermodynamic parameters of CpGAL unfolding in different states were estimated and interpreted using circular dichroism and fluorescence spectroscopic measurements. The enzyme was found to be structurally and functionally stable in the entire pH range and upto 50°C temperature. Further increase in temperature induces unfolding followed by aggregation. Chemical induced denaturation was found to be cooperative and transitions were irreversible, non-coincidental and sigmoidal. Free energy of protein unfolding (ΔG0) and unfolding constant (Kobs) were also calculated for chemically denatured CpGAL. Significance: The protein seems to use different pathways for unfolding in different environments and is a classical example of how the environment dictates the path a protein might take to fold while its amino acid sequence only defines its final three-dimensional conformation. The knowledge accumulated could be of immense biotechnological significance as well. © 2012 Kishore et al.

Joy K.P.,Banaras Hindu University | Singh V.,Banaras Hindu University | Singh V.,University of Delhi
General and Comparative Endocrinology | Year: 2013

Functional interactions between vasotocin (VT) and prostaglandins (PGs) in the regulation of final oocyte maturation (FOM) and ovulation were investigated in the catfish Heteropneustes fossilis. Incubation of post-vitellogenic follicles with VT resulted in significant increases of both PGF2α and PGE2 at 8 and 16h intervals. The rise was higher at 16h except in the 1000nM VT group, in which the PG levels decreased compared to the 100nM group (biphasic effect). VT was more effective to increase the PG levels in comparison to hCG or IT. The co-incubation of the follicles with both hCG (20IU/ml) and VT (100nM) increased significantly PGF2α level at 8h, higher than that elicited by each when incubated alone. Pre-incubation of the follicles with V1 receptor antagonist, alone or in co-incubation with VT, significantly inhibited the VT-stimulated PGF2α and PGE2 levels. Under similar conditions, V2 receptor antagonist did not affect the PGE2 levels. Both VT (100nM) and PGs stimulated FOM (germinal vesicle breakdown) and ovulation in a dose- and duration dependent manner, PGF2α was more effective. Incubation of postvitellogenic follicles with indomethacin (a non selective cyclooxygenase inhibitor) per se did not affect FOM and ovulation but significantly decreased VT and PG effects upon pre-incubation. The results suggest that the VT stimulation of PGs may be mediated mainly through the V1 receptor though the involvement of V2 receptor cannot be excluded. The article also discussed the positive interplay of gonadotropin, maturation-inducing steroid, VT and PG during FOM and ovulation. © 2013.

Singh S.K.,Banaras Hindu University | Singh M.K.,University of Aveiro | Kulkarni P.P.,Banaras Hindu University | Sonkar V.K.,Banaras Hindu University | And 2 more authors.
ACS Nano | Year: 2012

Graphene and its derivatives have attracted significant research interest based on their application potential in different fields including biomedicine. However, recent reports from our laboratory and elsewhere have pointed to serious toxic effects of this nanomaterial on cells and organisms. Graphene oxide (GO) was found to be highly thrombogenic in mouse and evoked strong aggregatory response in human platelets. As platelets play a central role in hemostasis and thrombus formation, thrombotoxicity of GO potentially limits its biomedical applications. Surface chemistry of nanomaterials is a critical determinant of biocompatibility, and thus differentially functionalized nanomaterials exhibit varied cellular toxicity. Amine-modified carbon nanotubes have recently been shown to possess cytoprotective action, which was not exhibited by their relatively toxic carboxylated counterparts. We, therefore, evaluated the effect of amine modification of graphene on platelet reactivity. Remarkably, our results revealed for the first time that amine-modified graphene (G-NH 2) had absolutely no stimulatory effect on human platelets nor did it induce pulmonary thromboembolism in mice following intravenous administration. Further, it did not evoke lysis of erythrocytes, another major cellular component in blood. These findings contrasted strikingly the observations with GO and reduced GO (RGO). We conclude that G-NH 2 is not endowed with thrombotoxic property unlike other commonly investigated graphene derivatives and is thus potentially safe for in vivo biomedical applications. © 2012 American Chemical Society.

Wilhelm K.,Max Planck Institute for Solar System Research | Dwivedi B.N.,Banaras Hindu University
New Astronomy | Year: 2014

A small effect expected from a recently proposed gravitational impact model (Wilhelm et al., 2013) is used to explain the remaining secular perihelion advance rates of the planets Mercury, Venus, Earth, Mars, and the asteroid (1566) Icarus - after taking into account the disturbances related to Newton's Theory of Gravity. Such a rate was discovered by Le Verrier (1859) for Mercury and calculated by Einstein (1915, 1916) in the framework of his General Theory of Relativity (GTR). Accurate observations are now available for the inner Solar System objects with different orbital parameters. This is important, because it allowed us to demonstrate that the quantitative amount of the deviation from an 1/r potential is - under certain conditions - only dependent on the specific mass distribution of the Sun and not on the characteristics of the orbiting objects and their orbits. A displacement of the effective gravitational from the geometric centre of the Sun by about 4400 m towards each object is consistent with the observations and explains the secular perihelion advance rates. © 2014 Elsevier B.V. All rights reserved.

Agarwal S.,Banaras Hindu University | Bhadauria B.S.,Babasaheb Bhimrao Ambedkar University
Transport in Porous Media | Year: 2011

In the present article, we study the effect of local thermal non-equilibrium on the linear and non-linear thermal instability in a nanofluid saturated rotating porous layer. The Darcy Model has been used for the porous medium, while the nanofluid layer incorporates the effect of Brownian motion along with thermophoresis. A three-temperature model is been used for the effect of local thermal non-equilibrium among the particle, fluid, and solid-matrix phases. The linear stability analysis is based on normal mode technique, while for nonlinear analysis a minimal representation of the truncated Fourier series analysis involving only two terms has been used. © 2011 Springer Science+Business Media B.V.

Ghatak A.,Banaras Hindu University | Mandal R.D.R.,Rajghat Besant School | Mandal B.P.,Banaras Hindu University
Annals of Physics | Year: 2013

We complexify a 1-d potential V (x) = V0cosh 2μ{ tanh [ (x -μd) / d] + tanh (μ) } 2 which exhibits bound, reflecting and free states to study various properties of a non-Hermitian system. This potential turns out a PT-symmetric non-Hermitian potential when one of the parameters (μ, d) becomes imaginary. For the case of μ → iμ, we have an entire real bound state spectrum. Explicit scattering states are constructed to show reciprocity at certain discrete values of energy even though the potential is not parity symmetric. Coexistence of deep energy minima of transmissivity with the multiple spectral singularities (MSS) is observed. We further show that this potential becomes invisible from the left (or right) at certain discrete energies. The penetrating states in the other case (d → i d) are always reciprocal even though it is PT-invariant and no spectral singularity (SS) is present in this case. The presence of MSS and reflectionlessness is also discussed for the free states in the later case. © 2013 Elsevier Inc.

Bhadauria B.S.,Babasaheb Bhimrao Ambedkar University | Bhadauria B.S.,Banaras Hindu University | Kiran P.,Babasaheb Bhimrao Ambedkar University
Transport in Porous Media | Year: 2013

Thermal instability in a horizontal porous medium saturated with temperature-dependant viscous fluid has been considered, and the effect of time-periodic temperature modulation has been investigated. The amplitudes of temperature modulation at the lower and upper surfaces are considered to be very small and the disturbances are expanded in terms of power series of amplitude of convection. A weak non-linear stability analysis has been performed for the stationary mode of convection, and heat transport in terms of the Nusselt number, which is governed by the non-autonomous Ginzburg-Landau equation, is calculated. The effects of thermo-rheological parameter, amplitude and frequency of modulation, thermo-mechanical anisotropies, and Vadasz number on heat transport have been analyzed and depicted graphically. It is found that an increment in the value of thermo-rheological parameter results in the enhancement of heat transport in the system. Further, the study establishes that the heat transport can be controlled effectively by a mechanism that is external to the system. © 2013 Springer Science+Business Media Dordrecht.

Vashista M.,Banaras Hindu University | Paul S.,Indian Institute of Technology Kharagpur
Philosophical Magazine | Year: 2012

The full width at half maximum (FWHM) of XRD profiles is used to characterize different material properties and surface integrity features. However, there is no literature available that discusses the nature of the correlation between the FWHM of XRD peaks with induced surface residual stress upon grinding with simultaneous occurrence of plastic deformation, formation of white layer, grain elongation, change in microhardness, etc. AISI 1060 steel samples were ground under different grinding domains, i.e. conventional abusive grinding, conventional grinding, cBN grinding and high speed grinding with moderately deep cut. Induction of tensile and compressive residual stress, microstructural changes, white layer formation, grain refinement, plastic deformation, grain elongation and change in microhardness were observed upon grinding AISI 1060 steel. A correlation was established between the FWHM of XRD peaks and surface residual stress when simultaneous changes in microhardness and microstructure, grain elongation, plastic deformation and formation of white layer take place due to grinding. The correlation between FWHM of XRD peak and residual stress appears to be nonlinear due to simultaneous change in other aspects of surface integrity. © 2012 Taylor and Francis Group, LLC.

Kaur S.,Banaras Hindu University | Dhillon G.S.,University of Alberta | Dhillon G.S.,University of Québec
Critical Reviews in Biotechnology | Year: 2015

The natural biopolymer chitin and its deacetylated product chitosan are widely used in innumerable applications ranging from biomedicine, pharmaceuticals, food, agriculture and personal care products to environmental sector. The abundant and renewable marine processing wastes are commercially exploited for the extraction of chitin. However, the traditional chitin extraction processes employ harsh chemicals at elevated temperatures for a prolonged time which can harm its physico-chemical properties and are also held responsible for the deterioration of environmental health. In view of this, green extraction methods are increasingly gaining popularity due to their environmentally friendly nature. The bioextraction of chitin from crustacean shell wastes has been increasingly researched at the laboratory scale. However, the bioextraction of chitin is not currently exploited to its maximum potential on the commercial level. Bioextraction of chitin is emerging as a green, cleaner, eco-friendly and economical process. Specifically in the chitin extraction, microorganisms-mediated fermentation processes are highly desirable due to easy handling, simplicity, rapidity, controllability through optimization of process parameters, ambient temperature and negligible solvent consumption, thus reducing environmental impact and costs. Although, chitin production from crustacean shell waste through biological means is still at its early stage of development, it is undergoing rapid progress in recent years and showing a promising prospect. Driven by reduced energy, wastewater or solvent, advances in biological extraction of chitin along with valuable by-products will have high economic and environmental impact. © 2015 Informa Healthcare USA, Inc.

Kaur S.,Banaras Hindu University | Dhillon G.S.,INRS
Critical Reviews in Microbiology | Year: 2014

Among the biopolymers, chitin and its derivative chitosan (CTS) have been receiving increasing attention. Both are composed of randomly distributed β-(1-4)-linked d-glucosamine and N-acetyl glucosamine units. On commercial scale, CTS is mainly obtained from the crustacean shells. The chemical methods employed for extraction of CTS from crustacean shells are laden with many disadvantages. Waste fungal biomass represents a potential biological source of CTS, in fact with superior physico-chemical properties, such as high degree of deacetylation, low molecular weight, devoid of protein contamination and high bioactivity. Researchers around the globe are attempting to commercialize CTS production and extraction from fungal sources. Fungi are promising and environmentally benign source of CTS and they have the potential to completely replace crustacean-derived CTS. Waste fungal biomass resulting from various pharmaceutical and biotechnological industries is grown on inexpensive agro-industrial wastes and its by-products are a rich and inexpensive source of CTS. CTS is emerging as an important natural polymer having broad range of applications in different fields. In this context, the present review discusses the potential sources of CTS and their advantages and disadvantages. This review also deals with potential applications of CTS in different fields. Finally, the various attributes of CTS sought in different applications are discussed. © 2014 Informa Healthcare USA, Inc. All rights reserved: reproduction in whole or part not permitted.

Singh B.K.,Banaras Hindu University | Thapa K.B.,CSJM University | Pandey P.C.,Banaras Hindu University
Optics Communications | Year: 2013

A theoretical study of optical reflectance and reflection bands of 1-D photonic quasi-crystals (Fibonacci type arrangement) composed of exponentially graded material is presented. The proposed structures consist of two different layers, one of them is of constant refractive index (L) and the other one is of exponentially graded refractive index (S) dielectric materials. Four different generations (2nd, 3rd, 4th and 5th) of the Fibonacci sequence for 10 periods in one dimension (1-D) are considered and compared in view of their optical reflectance and bandgaps for both TE and TM polarisations. Also, we proposed some heterostructures made by the combination of different Fibonacci generations and their periods to obtain suitable omnidirectional reflection band. We used the transfer matrix method (TMM) to obtain the reflectance, bandgaps and omnidirectional reflectional bandgaps (ODR) of such structures in near infrared spectrum (800-2200 nm) at different angles of incidence. We show that ODR exists in these types of structures. The number of ODRs and total bandgap depend on the Fibonacci generations. Extraordinary ODR bandgaps are obtained in the case of heterostructures formed by the combination of different generations of the Fibonacci sequence. The ODR for these structures is similar to the ODR of photonic crystals containing left-handed materials. This work would be useful to study the Fibonacci type photonic crystals having graded index materials and also it will open new window to design several photonic crystal devices like sensors, reflectors, etc. in the infrared region. © 2013 Elsevier B.V.

Bhadauria B.S.,Banaras Hindu University | Kiran P.,Babasaheb Bhimrao Ambedkar University
International Journal of Heat and Mass Transfer | Year: 2015

A weak onlinear analysis of double diffusive convection in an electrically conducting viscoelastic fluid layer heated from below, has been performed for the range of viscoelastic parameters where oscillatory mode exists. A uniform magnetic field has been applied vertically. Employing complex non-autonomous Ginzburg-Landau equation, the effects of various parameters on double diffusive convection is investigated. Weak nonlinear analysis reveals that the values of viscoelastic parameters have significant effect on the instability. The present study is to investigate the effect of time periodic gravity field on heat and mass transfer in the presence of external magnetic field, where controlling convection external to the system is important. It is found that the variation of Nusselt, Sherwood numbers with respect to the slow time becomes rapid upon increasing the solutal Rayleigh number Rs, Prandtl number Pr, time relaxation parameter λ and amplitude of modulation δ2 or decreasing on Chandrasekhar number Q, diffusivity ratio Γ, time retardation parameter ε and frequency of modulation Ω. It is found that the applied magnetic field has a stabilizing effect, hence reducing heat and mass transport in the system. Further, modulated gravity field can be used either to delay or enhance the heat and mass transfer in the system. Chaotic convection under gravity modulation has also been investigated using Lorenz model. © 2014 Elsevier Ltd. All rights reserved.

Chandel N.,Banaras Hindu University | Mehta N.,Banaras Hindu University | Kumar A.,Uttar Pradesh Technical University
Current Applied Physics | Year: 2012

The a.c. conductivity of a-Se80Te20 and a-Se 80Te10M10 (M = Cd, In, Sb) alloys has been investigated as a function of temperature in the range from 280 to 330 K and frequency in the range from 102 to 104 Hz. The experimental results indicate that a.c. conductivity σac is proportional to ωs where s < 1 and decreases with increasing temperature. The results obtained are discussed in terms of the correlated barrier hopping (CBH) model. An agreement between experimental and theoretical results suggests that the a.c. conductivity behavior of a-Se80Te 20 and a-Se80Te10M10 (M = Cd, In, Sb) system can be successfully explained by CBH model. The contribution of single polaron and bipolaron hopping to a.c. conductivity in present alloys is also studied. © 2011 Elsevier B.V. All rights reserved.

Mehta N.,Banaras Hindu University | Kumar A.,Uttar Pradesh Technical University
Journal of Non-Crystalline Solids | Year: 2012

Free volume model is widely used as a tool for understanding the nature of glass transition phenomenon and the related consequences. Recently, an analytical derivation of Kissinger's equation has been proposed in literature using free volume model. In this derivation, the glass transition activation energy has been assumed constant throughout the whole glass transition temperature range. The present paper investigates the applicability of free volume model for derivation of Kissinger's relation by checking the constancy of the glass transition activation energy (E g) throughout the glass transition temperature range. Performing series of experiments, we have legalized the possibility for usage of the Kissinger relation for determination of the glass transition activation energy if the peak value of the endo-thermal effect is taken as temperature of glass transition. © 2012 Elsevier B.V.

Bhandari V.,Safdarjung Hospital Campus | Sundar S.,Banaras Hindu University | Dujardin J.C.,Institute of Tropical Medicine | Dujardin J.C.,University of Antwerp | Salotra P.,Safdarjung Hospital Campus
Antimicrobial Agents and Chemotherapy | Year: 2014

Leishmania donoVani is the causative agent of the potentially fatal disease visceral leishmaniasis (VL). Chemotherapeutic options available to treat VL are limited and often face parasite resistance, inconsistent efficacy, and toxic side effects. Paromomycin (PMM) was recently introduced to treat VL as a monotherapy and in combination therapy. It is vital to unDerstand the mechanisms of PMM resistance to safeguard the drug. In the present study, we utilized experimentally generated PMM-resistant L. donoVani to elucidate the mechanisms of resistance and parasite biology. We found increased membrane fluidity accompanied by decreased intracellular drug accumulation in the PMM-resistant parasites. There were marked increases in gene expression of ATP-binding cassette (ABC) transporters (MDR1 and MRPA) and protein phosphatase 2A that evince increased drug efflux. Further, evaluation of parasite tolerance toward host leishmanicidal mechanisms revealed PMM-resistant parasites as being more tolerant to nitrosative stress at the promastigote and amastigote stages. The PMM-resistant parasites also predicted a better survival capacity, as indicated by resistance to complement-mediated lysis and increased stimulation of host interleukin-10 (IL-10) expression. The susceptibilities of PMM-resistant isolates to other antileishmanial agents (sodium antimony gluconate and miltefosine) remained unchanged. The data implicated the roles of altered membrane fluidity, decreased drug accumulation, increased expression of ABC transporters, and greater tolerance of parasites to host defense mechanisms in conferring PMM resistance in Leishmania. Copyright © 2014, American Society for Microbiology.

Chalapathi Rao N.V.,Banaras Hindu University | Srivastava R.K.,Banaras Hindu University | Sinha A.K.,Indian Institute of Geomagnetism | Ravikant V.,Indian Institute of Science
Earth-Science Reviews | Year: 2014

Mineral chemistry, bulk-rock geochemistry and radiogenic isotope (Sr and Nd) data of surface and sub-surface samples of early-Cretaceous Kerguelen mantle plume linked ultrapotassic intrusive rocks from previously unstudied localities of Raniganj and Jharia Gondwana sedimentary basins, Damodar Valley, eastern India, are presented. Despite considerable textural diversity and variable mineralogy these rocks display broadly similar geochemistry highlighting their co-genetic nature. Their bulk-geochemical and petrographic characteristics are similar to those of ultramafic lamprophyres and liquidus mineral composition are closer to that of lamproites and are strikingly comparable to ultrapotassic rocks reported from the Denizli region (Western Anatolia, Turkey), Karinya Syncline and Mt. Bundey (Australia) and the Polayapalle, eastern Dharwar craton (southern India). Incompatible trace element concentrations (e.g., Sr, Zr, Nb, Ta etc.) and their ratios (Ce/Pb, Nb/U, Nb/Yb, Th/Yb) reveal limited influence of crustal contamination and involvement of a predominantly within-plate (plume) and minor subduction-derived components in their magmas. Initial Sr-Nd isotopic ratios of the Damodar Valley ultrapotassic intrusives suggest their derivation from source regions with long term incompatible element enrichment relative to that of Bulk Earth which are very different from those of (i) kimberlites and orangeites from India and southern Africa and (ii) primitive Kerguelen plume component but indistinguishable from those of the pristine Kerguelen mantle plume derived basalts. The depleted mantle (TDM) model ages (0.95-1.4Ga) of the Damodar Valley ultrapotassic rocks are strikingly similar to (i) those of the Deccan-age orangeites from the Bastar craton, central India, and (ii) the emplacement ages (1.1-1.4Ga) of kimberlites and lamproites from the eastern Dharwar craton, southern India. The Gondwana ultrapotassic rocks represent small degree-partial melts derived from a depleted harzburgitic source subsequently metasomatised by carbonate- and rutile-rich fluids/melts, presumably derived from Kerguelen plume, within the garnet stability field at lithospheric depths. A temporal difference of ~500Ma in the source enrichment of Jharia and Raniganj ultrapotassic intrusives, coupled with their distinct incompatible element signatures, bring out involvement of a heterogeneous mantle in their genesis. © 2014 Elsevier B.V.

Meshram M.K.,Banaras Hindu University | Animeh R.K.,McMaster University | Pimpale A.T.,Research in Motion Ltd. | Nikolova N.K.,McMaster University
IEEE Transactions on Antennas and Propagation | Year: 2012

A novel quad-band diversity antenna is presented with two radiating elements suitable for long-term evolution (LTE) and wireless fidelity (Wi-Fi) applications in handheld devices. The radiating elements are two planar inverted F-shaped antennas (PIFA) constructed by a meandered line and folded patch with interdigitated capacitive strips connected to the folded patch. To achieve high isolation between the two radiating elements, a defected ground plane (a combination of rectangular slot ring and inverted T-shaped slot stub) is employed. The antenna is designed to operate in the 746-787 MHz, 1850-1990 MHz, 1920-2170 MHz, and 3600-3700 MHz frequency bands. The characterization of the antenna in free-space as well as in the proximity of the user head and hand is presented. The results confirm the excellent performance of the proposed diversity antenna. © 1963-2012 IEEE.

Dhillon G.S.,University of Québec | Kaur S.,Banaras Hindu University | Brar S.K.,University of Québec
Renewable and Sustainable Energy Reviews | Year: 2013

The fruit processing industries are experiencing surge due to the increasing demand of food products as a result of burgeoning human population. Apple and apple products are one of the major fruit and fruit products consumed all over the world. Apple processing industries generate huge quantities of solid and liquid sludge wastes. The solid residues consist of a mixture of skin, pulp and seeds derived from the production of concentrated apple juice, jam, and sweets and are collectively known as 'apple pomace'. Being highly biodegradable, the disposal of these wastes represents a serious environmental problem and presents many challenges. Often only 20% is retrieved as animal feed and the rest 80% goes to landfill, is incinerated or is sent to composting sites which results in release of greenhouse gases. However, advancement in technology has led to the alternative options of utilization of apple pomace. It can be used as a promising raw material for direct extraction of bioactive compounds and bioproduction of high value-added products, such as enzymes, organic acids, biofuels, among other products. This article reviews the work done for value-addition of this precious biomass which can help in setting up integrated process in the existing apple industries itself or separate small scale industries. © 2013 Elsevier Ltd.

Soni D.K.,Banaras Hindu University | Singh R.K.,Institute of Life science | Singh D.V.,Institute of Life science | Dubey S.K.,Banaras Hindu University
Infection, Genetics and Evolution | Year: 2013

Listeria monocytogenes isolated from Ganges water, human clinical and milk samples were characterized by antibiotic susceptibility, serotype identification, detection of virulence genes and ERIC- and REP-PCR fingerprint analyses. All isolates were uniformly resistant to ampicillin, except two isolates, and showed variable resistance to gentamicin, cotrimoxazole, ofloxacin, rifampicin and tetracycline. Of the 20 isolates found positive for pathogens, seven (four human and three water isolates) belong to serogroups 4b, 4d and 4e; six (one human and five water isolates) belong to serogroups 1/2c and 3c; four milk isolates belong to serogroups 1/2b and 3b; and three milk isolates belong to serogroups 1/2a and 3a. Two water isolates, all human isolates, except one (Pb1) lacking inlJ gene, and three milk isolates possess inlA, inlC, plcA, prfA, actA, hlyA and iap genes. The remaining water and milk isolates showed variable presence of inlJ, plcA, prfA, and iap genes. ERIC- and REP-PCR based analyses collectively indicated that isolates of human clinical samples belong to identical or similar clone and isolates of water and milk samples belong to different clones. Overall study demonstrates the prevalence of pathogenic L. monocytogenes species in the environmental and clinical samples. Most of the isolates were resistant to commonly used antibiotics. © 2012 Elsevier B.V.

Verma V.C.,Banaras Hindu University | Kharwar R.N.,Royal Holloway, University of London | Gange A.C.,Royal Holloway, University of London
Nanomedicine | Year: 2010

Aim: To induce the biosynthesis of silver nanoparticles (AgNPs) using Aspergillus clavatus and evaluate their antimicrobial potential. Materials & methods: Aspergillus clavatus (AzS-275), an endophytic fungus isolated from sterilized stem tissues of Azadirachta indica A. Juss., was challenged with 1 mM AgNO3 solution. The characterization of the AgNPs was carried out by x-ray diffraction spectrometry, transmission-electron microscopy and atomic force microscopy. Results & discussion: The synthesized AgNPs were found to be extracellular, polydispersed spherical or hexagonal particles ranging from 10 to 25 nm in size. Antimicrobial activity was performed using a disc-diffusion method against Candida albicans, Pseudomonas fluorescens and Escherichia coli. The results showed an average minimum inhibitory concentration of 5.83μg ml-1 and minimum fungicidal concentration of 9.7 μg ml -1 against C. albicans. Conclusions: AgNPs can be mycosynthesized extracellularly using A. clavatus as the fungal system, which is highly advantageous over chemical synthesis not only because it can be synthesized on a large scale, but because of the ease of downstream processing and its biomedical application in antimicrobial activity. © 2010 Future Medicine Ltd.

Sengar N.,Banaras Hindu University | Joshi A.,Banaras Hindu University | Prasad S.K.,Banaras Hindu University | Prasad S.K.,Rashtrasant Tukadoji Maharaj Nagpur University | Hemalatha S.,Banaras Hindu University
Journal of Ethnopharmacology | Year: 2015

Ethnopharmacological relevance The plant Jasminum sambac L. (Oleaceae) is cultivated throughout India. The leaves and roots of the plant are used traditionally in the treatment of inflammation, fever and pain. The leaves of the plant have been reported to posses significant anti-inflammatory and analgesic activities.Objective: To scientifically validate anti-inflammatory, analgesic and anti-pyretic activities of roots from Jasminum sambac.Materials and methods Ethanol root extract of Jasminum sambac (EJS) was standardized using HPTLC and was subjected to acute oral toxicity study. Further, analgesic activity of EJS at 100, 200 and 400 mg/kg, p.o. was evaluated using writhing test on Swiss albino mice and tail-flick test on Charles Foster albino rats. Anti-inflammatory activity of EJS was assessed by carrageenan-induced rat paw edema, cotton pellet-induced granuloma and Freund's adjuvant-induced arthritis models, while antipyretic activity was evaluated using Brewer's yeast induced pyrexia. In addition, biochemical parameters such as alkaline phosphatase (ALP), aspartate transaminase (AST), alanine transaminase (ALT), lipid peroxidation (LPO), superoxide dismutase (SOD) and catalase (CAT) in blood serum and edematous tissue of rats exposed to acute (carrageenan) and granulomatous tissue in sub-chronic (cotton pellet granuloma) inflammation models were also evaluated.Results Phytochemical analysis of EJS revealed the presence of flavonoids, phenols, saponins, tannins and carbohydrates in major quantities, while the quantity of hesperidin in EJS (using HPTLC) was found to be 4.25% w/w. EJS at 400 mg/kg, p.o. reduced writhing count up to 49.21%, whereas in tail-flick test, EJS in a dose dependent manner increased latency in flicking tail. EJS at 400 mg/kg, p.o. showed significant anti-inflammatory activity after 2nd, 3rd, 4th and 6th h of treatment in carrageenan-induced edema, while a 33.58% inhibition in cotton pellet induced granuloma formation was observed at same dose level. EJS significantly (p<0.001) inhibited adjuvant-induced arthritis and also showed significant antipyretic activity. Further, a significant reversal in alterations of all the biochemical parameters (except ALP) in tissues was also observed.Conclusions The study confirms the anti-inflammatory, analgesic and antipyretic activity of EJS which may be attributed to the presence of various phytoconstituents quantified especially hesperidin which have already been reported for its significant role in the treatment of inflammation and associated problems. © 2014 Elsevier Ireland Ltd.

Harsha A.P.,Banaras Hindu University | Joyce T.J.,Northumbria University
Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine | Year: 2011

For appropriate in vitro wear testing of prostheses and their biomaterials, the choice of lubricant is critical. Bovine serum is the lubricant recommended by several international standards for wear testing artificial joints and their biomaterials because the wear rate and wear mechanisms closely match clinical results of polyethylene bearings. The main problem with the use of bovine serum as a lubricant is protein degradation and precipitation formation, effects that are recognized as having a direct impact on wear processes. Hence, some researchers have questioned the validity of using bovine serum in simulator testing. This paper reviews the various lubricants used in laboratory wear studies and also the properties of the synovial fluid that the lubricant is trying to replicate. It is clear from the literature survey that the composition of bovine-serum-based lubricants does not match that of synovial fluid. In view of this conclusion, it is suggested that there is a need to develop an alternative lubricant that can replace bovine serum. © IMechE 2011.

Yadav S.K.,Banaras Hindu University | Kumar A.,University of Lucknow | Kumar N.,Banaras Hindu University
Journal of Hydrology | Year: 2012

Transport of solute mass transport, originating from a uniform pulse-type stationary point source through a heterogeneous semi-infinite horizontal medium, is studied. The heterogeneity is described by position dependent linear non-homogeneous expression for the velocity. The exponential unsteady variation in velocity of decreasing/increasing is also considered. The variation in dispersion parameter due to heterogeneity is considered proportional to square of that in the velocity. But the same due to unsteadiness is proportional to a power of the velocity which may take any value between 1 and 2 or outside this range. The variable coefficients of the two-dimensional advection-diffusion equation are put in degenerate form. These are reduced into constant coefficients with the help of new independent variables introduced at different stages, paving the way for using Laplace transformation technique to get the desired solution. © 2011 Elsevier B.V.

Singh A.K.,Japan National Institute of Advanced Industrial Science and Technology | Pandey D.S.,Banaras Hindu University | Xu Q.,Japan National Institute of Advanced Industrial Science and Technology | Braunstein P.,CNRS Coordination Chemistry
Coordination Chemistry Reviews | Year: 2014

Since the synthesis of the first arene ruthenium complexes in 1967, various groups have systematically investigated the chemistry of this family of complexes because of their appealing structural diversity, related to the ways in which the arene ligand can be functionalized, their role as versatile stereochemical controlling elements in areas such as catalysis, chemical and photochemical sensing, biology and supramolecular chemistry, and their potential as metalloligands. This review is focused on the recent developments of arene ruthenium complexes towards both supramolecular chemistry and biology. Arene ruthenium complexes can form various supramolecular structures with applications as chemical/photochemical sensors, in medicine and for drug transport inside the cell. Recent developments in the chemistry of arene ruthenium complexes will likely give access to a variety of metal-based drugs/sensors within the next few years. © 2013 Elsevier B.V.

Yadav A.K.,Banaras Hindu University | Gautam C.R.,University of Lucknow | Singh P.,Banaras Hindu University
RSC Advances | Year: 2015

An attempt has been made to prepare barium strontium titanate borosilicate glasses in the system, 64[(Ba1-xSrx)·TiO3]-30[2SiO2·B2O3]-5[K2O]-1[Fe2O3] (0.4 ≤ x ≤ 1.0), using the conventional melt-quench method. The prepared glasses were characterized by differential thermal analysis, X-ray diffraction, scanning electron microscopy and impedance spectroscopy techniques. On the basis of the DTA results, the glasses were crystallized via regulated heat treatment process. The activation energy for crystallization was 818 ± 1.6 kJ mol-1. A high dielectric constant of about 107 070 was obtained for the 6 hour heat treated glass ceramic sample. Fe2O3 plays an important role in enhancing crystallization, dielectric constant and retardation of dielectric loss in the samples. © The Royal Society of Chemistry 2015.

Singh Y.N.,University of Lucknow | Singh S.K.,Banaras Hindu University
Proceedings of the 2011 World Congress on Information and Communication Technologies, WICT 2011 | Year: 2011

Biometric authentication systems have become the basis of trust to human society from the beginning of last decade, but the security of the system can be breached by presenting a non-live or fake biometric sample which is the cloned of a legitimate user's identity. Different techniques have been proposed to address the problem of vitality detection from biometrics but these techniques are far away from the final solution. This paper proposes a classification of vitality detection techniques for fingerprint, face and iris biometrics for summarizing the current state-of-the-art and presents a critical review of them. We evaluate the potential of multimodal techniques of vitality detection from biometrics and analyze the performance of different vitality detection techniques on the datasets and the test conditions that have used. The use of physiological signals that have the inherited feature of vitality signs as a supplementary information with other conventional biometrics can offer a potential defense against spoofing attacks in the system. © 2011 IEEE.

Saravanan R.S.S.,Physics Research Center | Pukazhselvan D.,Banaras Hindu University | Mahadevan C.K.,Physics Research Center
Journal of Alloys and Compounds | Year: 2011

Zn(1-x)CdxS and Zn(1-x)Cd xS:Mn2+ semiconductor quantum dots (2-4 nm) have been prepared by a novel solvothermal route assisted microwave heating method. The growth parameters governing the smaller size and higher yield have been optimized. The synthesized QDs exhibit a significant blue shift as compared to their corresponding bulk counterpart in the UV-vis optical absorption spectrum. The dielectric constant value varies from 2.79 to 6.17 (at 40 °C, 1 kHz) depending upon the composition of the alloy; lower value corresponds to Zn 0.75Cd0.25S:Mn2+ and the higher value corresponds to Zn0.25Cd0.75S:Mn2+. The crystallite size to exciton bohr radius ratio being <1 indicates a strong quantum confinement effect in both CdS and ZnS QDs. The quantum confinement effect exists in the sequence of ZnS:Mn2+ < Zn (1-x)CdxS:Mn2+ (x < 0.5) < ZnS < Zn(1-x)CdxS < CdS < CdS:Mn2+. © 2011 Elsevier B.V. All rights reserved.

Saravanan R.S.S.,Physics Research Center | Pukazhselvan D.,Banaras Hindu University | Mahadevan C.K.,Physics Research Center
Journal of Alloys and Compounds | Year: 2012

This paper presents a comparative analysis of ZnS QDs synthesized by conventional and microwave heating techniques using zinc acetate and sodium sulphide reactants. The size of the quantum dots achieved by the latter technique (∼3 nm) is at least 30 times smaller than the former technique. Incorporation of excess Na 2S and microwave treatment are the important factors responsible for controlling the size of ZnS nanocrystals. Furthermore, the distribution of quantum dots is highly influenced by the addition of small amount of NaOH. The UV-vis analysis reveals that the band gap can be widened up to 3.94 eV (correspond to ∼3 nm ZnS) from 3.67 eV (correspond to bulk ZnS). Surprisingly better conductivity is observed for the widest band gap ZnS of the present study; this could be due to defects/vacancies present in the system and its influence in the band structure. The higher conductivity value is supported by the smaller activation energy value, smaller dielectric constant and higher dielectric loss, etc. The conduction is further explained by thermionic emission mechanism. © 2011 Elsevier B.V.

Pandey A.S.,Kamla Nehru Institute of Technology | Singh D.,Banaras Hindu University | Sinha S.K.,Kamla Nehru Institute of Technology
IEEE Transactions on Power Systems | Year: 2010

A wavelet decomposition based load forecast approach is proposed for 24-h and 168-h ahead short-term load forecasting. The proposed approach is applied to and compared with representative load forecasting methods such as: time series in traditional approaches and RBF neural network and neuro-fuzzy forecaster in nontraditional approaches. The other forecasters, such as multiple linear regression (MLR), time series, feed forward neural network (FFNN), radial basis function neural network (RBFNN), clustering, and fuzzy inference neural network (FINN), reported in the literature are also compared with the present approach. The process of the proposed wavelet decomposition approach is that it first decomposes the historical load and weather variables into an approximate part associated with low frequencies and several detail parts associated with high frequencies components through the wavelet transform. The historical data are smoothened by deleting the high frequency components and fed as input to the proposed models for the prediction. A comparison of wavelet and non-wavelet based approaches shows the superiority of proposed wavelet based approach over non-wavelet methods for the same set of data of the same utility. © 2010 IEEE.

Singh A.K.,Banaras Hindu University | Singh M.,Indian Institute of Vegetable Research | Dubey S.K.,Banaras Hindu University
BMC Microbiology | Year: 2013

Background: The global area under brinjal cultivation is expected to be 1.85 million hectare with total fruit production about 32 million metric tons (MTs). Brinjal cultivars are susceptible to a variety of stresses that significantly limit productivity. The most important biotic stress is caused by the Brinjal fruit and shoot Borer (FSB) forcing farmers to deploy high doses of insecticides; a matter of serious health concern. Therefore, to control the adverse effect of insecticides on the environment including the soil, transgenic technology has emerged as the effective alternative. However, the reports, regarding the nature of interaction of transgenic crops with the native microbial community are inconsistent. The effect of a Bt transgenic brinjal expressing the bio-insecticidal protein (Cry1Ac) on the rhizospheric community of actinomycetes has been assessed and compared with its non-transgenic counterpart. Results: Significant variation in the organic carbon observed between the crops (non-Bt and Bt brinjal) may be due to changes in root exudates quality and composition mediated by genetic attributes of Bt transgenic brinjal. Real time quantitative PCR indicated significant differences in the actinomycetes- specific 16S rRNA gene copy numbers between the non-Bt (5.62-27.86) × 1011 g-1 dws and Bt brinjal planted soil (5.62-24.04) × 1011 g-1 dws. Phylogenetic analysis indicated 14 and 11, actinomycetes related groups in soil with non-Bt and Bt brinjal crop, respectively. Micrococaceaea and Nocardiodaceae were the dominant groups in pre-vegetation, branching, flowering, maturation and post-harvest stage. However, Promicromonosporaceae, Streptosporangiaceae, Mycobacteriaceae, Geodermatophilaceae, Frankiaceae, Kineosporaceae, Actisymmetaceae and Streptomycetaceae were exclusively detected in a few stages in non-Bt brinjal rhizosphere soil while Nakamurellaceae, Corynebactericeae, Thermomonosporaceae and Pseudonocardiaceae in Bt brinjal counterpart. Conclusion: Field trails envisage that cultivation of Bt transgenic brinjal had negative effect on organic carbon which might be attributed to genetic modifications in the plant. Changes in the organic carbon also affect the actinomycetes population size and diversity associated with rhizospheric soils of both the crops. Further long-term study is required by taking account the natural cultivar apart from the Bt brinjal and its near-isogenic non-Bt brinjal with particular reference to the effects induced by the Bt transgenic brinjal across different plant growth stages. © 2013 Singh et al.; licensee BioMed Central Ltd.

Pandhija S.,Allahabad University | Rai N.K.,Allahabad University | Rai A.K.,Allahabad University | Thakur S.N.,Banaras Hindu University
Applied Physics B: Lasers and Optics | Year: 2010

The present paper deals with the detection and quantification of toxic heavy metals like Cd, Co, Pb, Zn, Cr, etc. in environmental samples by using the technique of laser-induced breakdown spectroscopy (LIBS) and calibration-free LIBS (CF-LIBS). A MATLABTM program has been developed based on the CF-LIBS algorithm given by earlier workers and concentrations of pollutants present in industrial area soil have been determined. LIBS spectra of a number of certified reference soil samples with varying concentrations of toxic elements (Cd, Zn) have been recorded to obtain calibration curves. The concentrations of Cd and Zn in soil samples from the Jajmau area, Kanpur (India) have been determined by using these calibration curves and also by the CF-LIBS approach. Our results clearly demonstrate that the combination of LIBS and CF-LIBS is very useful for the study of pollutants in the environment. Some of the results have also been found to be in good agreement with those of ICP-OES. © 2009 Springer-Verlag.

Srivastava P.K.,Banaras Hindu University | Mishra M.,Birla Institute of Technology and Science | Singh C.P.,Banaras Hindu University
Physical Review C - Nuclear Physics | Year: 2013

We present a modified color screening model for J/ψ suppression in the quark-gluon plasma (QGP) using the quasiparticle model (QPM) as the equation of state (EOS). Other theoretical ingredients incorporated in the model are feed-down from higher resonances, namely, χc, and ψ′, dilated formation time for quarkonia, and viscous effects of the QGP medium. By assuming further that the QGP is expanding with Bjorken's hydrodynamical expansion, the present model is used to analyze the centrality dependence of the J/ψ suppression in the mid-rapidity region and compare it with the data obtained from Super Proton Synchrotron, Relativistic Heavy Ion Collider, and Large Hadron Collider experiments. We find that the centrality dependence of the data for the survival probability at all energies is well reproduced by our model. We further compare our model predictions with the results obtained from the bag model EOS for QGP which has usually been used earlier in all such calculations. © 2013 American Physical Society.

Faizal M.,University of Oxford | Mandal B.P.,Banaras Hindu University | Upadhyay S.,Banaras Hindu University
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2013

In this Letter we analyse the Bagger-Lambert-Gustavsson (BLG) theory in N=1 superspace. Furthermore, we will construct the BRST transformations for this theory. These BRST transformations will be integrated out to obtain the finite field dependent version of BRST (FFBRST) transformations. We will also analyse the effect of the FFBRST transformations on the effective action. We will thus show that the FFBRST transformations can be used to relate generating functionals of the BLG theory in two different gauges. © 2013 Elsevier B.V.

Singh V.K.,Banaras Hindu University | Singh M.P.,Allahabad University
Cellular and Molecular Biology | Year: 2014

Pleurotus ostreatus was grown on paddy straw as well as other vegetable and agricultural wastes i.e. pea pod shell, cauliflower leaves, radish leaves and brassica straw in various combinations with paddy straw. The mushroom did not grow on the vegetable wastes separately. The cumulative yield and biological efficiency of the edible oyster mushroom P. ostreatus grown on substrate containing paddy straw in various combinations with different vegetable wastes i.e. 20% and 30 % vegetable wastes mixed with 80% and 70% (w/w) of paddy straw was found to be better, when compared with yield and biological efficiency obtained on paddy straw (100%) alone. The protein content and six essential amino acid contents (Leu, Ile, Val, Thr, Met, Phe) showed a significant increase and total sugar and reducing sugar contents showed decrease in the mushroom fruit bodies grown at different combinations of vegetable wastes with paddy straw as compared to paddy straw alone. However, there was not any significant change in moisture content of mushroom cultivated on different groups of wastes. Hence, results of this investigation suggest that the vegetable wastes which are generally left to rot in situ in many cities and villages causing outbreak of diseases can be bioremediated by edible mushroom P. ostreatus. The added advantage is that we get edible mushroom fruit body with improved nutrition. © 2014.

Kumar A.,Banaras Hindu University | Pandey A.C.,Allahabad University | Prakash R.,Banaras Hindu University
Catalysis Science and Technology | Year: 2012

We report a chemical oxidative method for polyindole-tinoxide (Pin-SnO 2) synthesis and its electro-catalytic application. Our method consists of chemical polymerization of an indole monomer in the presence of dispersed nano SnO 2 at two different pHs i.e. below and above the isoelectric point of the SnO 2. Nano SnO 2 with crystallite sizes of nearly 5.0 nm are prepared by precipitation technique. For the sake of comparison, pristine polyindole is also synthesized by the same chemical method. These materials are characterized by XRD, FTIR and TEM. Characterization confirms the presence of nano SnO 2 particles in a Pin matrix and the effect of pH on the formation of a uniform nanocomposite and the extent of interaction of fillers and matrix. The electro-catalytic properties of the Pin-SnO 2 nanocomposite are investigated for formic acid oxidation using the voltammetric technique. This shows excellent synergic effect for electro-catalytic activity of the low doped Pin-SnO 2 nanocomposite (Pin-SnO 2 nanocomposite formed at higher pH). This composite is well suited for CO tolerance during the oxidation of formic acid in acidic medium and follows a direct pathway to convert it into CO 2. © 2012 The Royal Society of Chemistry.

Hasan M.,Satellite Center | Ghatak A.,Banaras Hindu University | Mandal B.P.,Banaras Hindu University
Annals of Physics | Year: 2014

We consider a non-Hermitian medium with a gain and loss symmetric, exponentially damped potential distribution to demonstrate different scattering features analytically. The condition for critical coupling (CC) for unidirectional wave and coherent perfect absorption (CPA) for bidirectional waves are obtained analytically for this system. The energy points at which total absorption occurs are shown to be the spectral singular points for the time reversed system. The possible energies at which CC occurs for left and right incidence are different. We further obtain periodic intervals with increasing periodicity of energy for CC and CPA to occur in this system. © 2014 Elsevier Inc.

Kumar D.,PGIMER and Dr Ram Manohar Lohia Hospital | Bagri N.,Banaras Hindu University
Indian Pediatrics | Year: 2015

Pediatric cardiology is outgrowing from the shadows of adult cardiology and cardiac surgery departments in India. It promises to be an attractive and sought-after subspeciality of Pediatrics, dealing with not only congenital cardiac diseases but also metabolic, rheumatic and host of other cardiac diseases. The new government policy shall provide more training avenues for the budding pediatric cardiologists, pediatric cardiac surgeons, pediatric anesthetists, pediatric cardiac intensivists, neonatologists and a host of supportive workforce. The proactive role of Indian Academy of Pediatrics and Pediatric Cardiac Society of India, towards creating a political will at the highest level for framing policies towards building infrastructure, training of workforce and subsidies for pediatric cardiac surgeries and procedures shall fuel the development of multiple tertiary cardiac centers in the country, making pediatric cardiology services accessible to the needy population. © 2015, Indian Academy of Pediatrics.

Chowdhury S.,Banaras Hindu University | Chanda T.,Banaras Hindu University | Koley S.,Banaras Hindu University | Ramulu B.J.,Banaras Hindu University | And 2 more authors.
Organic Letters | Year: 2013

An operationally simple, facile, and convenient one-pot straightforward method for the construction of 3,4,5-trisubstituted 1,2-dithioles has been explored and developed via palladium catalyzed self-coupling of α-enolic dithioesters for the first time. Pd(0) efficiently catalyzes the activation and cleavage of S-H and C-S bonds to achieve cascade coupling, which results in the concomitant formation of new S-S and C-C bonds. Optimization data, substrate scope, and mechanistic insights are discussed. © 2013 American Chemical Society.

Patwardhan K.,Banaras Hindu University | Patwardhan K.,Institute of Ayurveda and Integrative Medicine
American Journal of Physiology - Advances in Physiology Education | Year: 2012

Ayurveda, the nativehealthcare system of India, is a rich resource of well-documentedancient medical knowledge. Although the roots of this knowledge dateback to the Vedic and post-Vedic eras, it is generally believed that adedicated branch for healthcare was gradually established approximatelybetween 400 BCE and 200 CE. Probably because the languageof documentation of these early textbooks is in Sanskrit, a languagethat is not in day-to-day use among the general population even inIndia, many significant contributions of Ayurveda have remainedunrecognized in the literature related to the history of medicine. In thiscommunication, the discovery of blood circulation has been taken upas a case, and a few important references from the representativeAyurveda compendia that hint at a preliminary understanding of thecardiovascular system as a "closed circuit" and the heart acting as apump have been reviewed. The central argument of this review is thatthese contributions from Ayurveda too must be recorded and creditedwhen reviewing the milestones in the history of medicine, asAyurveda can still possibly guide various streams of the currentsciences, if revisited with this spirit.

Mittal A.K.,National Institute of Pharmaceutical Education and Research | Bhaumik J.,National Institute of Pharmaceutical Education and Research | Kumar S.,Banaras Hindu University | Banerjee U.C.,National Institute of Pharmaceutical Education and Research
Journal of Colloid and Interface Science | Year: 2014

The synthesis of silver nanoparticles (AgNPs) was accomplished using Syzygium cumini fruit extract at room temperature. Various techniques were used to characterize the newly synthesized silver nanoparticles and their size was determined to be 10-15. nm. Important findings of this study were the identification of biomolecules responsible for the synthesis of silver nanoparticles and elucidate the mechanism of biosynthesis. Flavonoids present in S. cumini were mainly responsible for the reduction and the stabilization of nanoparticles. The antioxidant properties of AgNPs were evaluated using various assays. The nanoparticles were also found to destroy Dalton lymphoma cell lines under in vitro condition. Silver nanoparticles (100. μg/mL) decreased the viability of Dalton lymphoma (DL) cell lines up to 50%. The studies describing the biosynthesis of silver nanoparticles by fruit extract followed by the investigation of synthesis mechanism and anti-cancer activities may be useful for nanobiotechnology research opening a new arena in this field. © 2013 Elsevier Inc.

Recent measurements have demonstrated unprecedented increase in atmospheric deposition of nutrients in many parts of India. To determine whether atmospheric nutrient inputs would increase phytoplankton growth and catchment dissolved organic carbon (DOC) flushing to constrain benthic algae, we analyzed NO3 - and PO4 -3 in atmospheric deposits; nutrients and DOC in runoff and lake water and standing crop biomass of phytoplankton and periphyton at Jaisamand Lake of Rajasthan, India. Atmospheric deposition of NO3 - (7. 18-29. 95 kg ha-1year-1) and PO4 -3 (0. 56-2. 15 kg ha-1year-1) showed a consistently rising trend across the year. Microbial biomass and activity in catchment increased in response to atmospheric deposition. Lake DOC and nutrients showed strong coherence with their terrestrial and atmospheric fluxes. Phytoplankton development showed significant linearity with atmospheric input of nutrients. Air-driven input appeared to have compensated the nutrient constraints to phytoplankton during drought. The N:P stoichiometry of deposition and that of lake water indicated that, although there was a seasonal switchover to N- or P-limitation, phytoplankton were mainly co-limited by N and P due probably to the synergistic effects of combined N + P enrichment in the pelagic zone of the lake. Periphyton standing crop showed inverse relationship with phytoplankton and lake DOC. The study indicated that enhanced phytoplankton development and terrestrial DOC flushing in response to atmospheric nutrient input attenuated light penetration to constrain algal periphyton. We suggests that data on these issues may be considered in developing aquatic ecosystem models to establish future links between changing air-water-land interactions and associated shifts in lake ecosystem functioning for more accurately predicting climate change drivers and designing integrated lake basin management strategies. © 2012 Springer Science+Business Media B.V.

Singh S.K.,Indian Institute of Technology Indore | Pandey D.S.,Banaras Hindu University
RSC Advances | Year: 2014

Biological properties of the arene-ruthenium complexes have attracted substantial current interest. Their activity is appreciably defined and controlled by the arene moieties, organic ligands and the metal center. In this review, we discuss the interaction of arene-ruthenium complexes with significant biomolecular targets (DNA and enzymes). Principally, active complexes may interact with the biomolecular targets DNA or nucleobases either by direct coordination facilitated by aquation of the complex or by intercalation/stacking of the pendant planar part of the complex, usually from the planar ancillary ligands or arenes with extended rings, between the DNA base pairs. On the other hand, kinetically inert metal complexes can also provide a potential tool (as enzyme inhibitors) for the targeting of important biomolecules (other than DNA), such as protein kinases. At the same time, coordination with a metal facilitates the outreach of the organic molecules in the intracellular region. This review also highlights the photodriven activation of arene-ruthenium complexes, important metal-drug interactions and the potential of multinuclear scaffolds as important drug candidates (e.g., metallodendrimers) and drug carriers (e.g. metallacages) for targeted delivery and activity. © 2014 The Royal Society of Chemistry.

Tiwari V.K.,Banaras Hindu University | Shripathi T.,University Campus | Lalla N.P.,University Campus | Maiti P.,Banaras Hindu University
Nanoscale | Year: 2012

We have developed multifunctional nanohybrids of poly(vinylidene fluoride-co-chlorotrifluoroethylene) (CTFE) with a small percentage of surface modified inorganic layered silicate showing dramatic improvement in toughness, radiation resistant and piezoelectric properties vis-à-vis pristine polymer. Massive intercalation (d001 1.8 → 3.9 nm) of polymer inside the nanoclay galleries and unique crystallization behavior of the fluoropolymer on the surface of individual silicate layer has been reported. Toughness in the nanohybrid increases more than three orders of magnitude as compared to pure CTFE. High energy radiation (80 MeV Si+7) causes chain session, amorphization and creates olefinic bonds in the pure polymer while the nanohybrids are radiation resistant at a similar dose. Nanoclay induces the metastable piezoelectric β-phase in CTFE, suitable for sensor and actuator application. Molecular level changes after irradiation and controlled morphology for smart membrane have been confirmed by using spectroscopy, sol-gel technique, surface morphology studies and in situ residual gas analysis.

Gopal R.N.,Banaras Hindu University | Kumar P.,Rajiv Gandhi University | Lal B.,Banaras Hindu University
General and Comparative Endocrinology | Year: 2014

Effects of growth hormone on somatic growth and testicular activities were studied during late quiescence and early recrudescence phases of the reproductive cycle of the catfish, Clarias batrachus. The administration of exogenous growth hormone (GH) during the late quiescence phase (December-January; ambient water temperature-15.2. ±. 1. °C) did not influence the somatic growth as well as the testicular activity, as no change in body weight, testis weight, plasma level of insulin-like growth factor I (IGF-I) and testicular morphology was detected following GH treatment, though the plasma testosterone was marginally increased. While during the early recrudescence phase (March-April; ambient water temperature-28.1. ±. 2. °C), GH treatment promoted the production of insulin like growth factor-I and testicular steroidogenic activity in a dose dependent manner, as was evident from the significant increase in the circulating levels of testosterone and estradiol-17β. GH treatment also increased body weight, testicular weight and gonadosomatic index, suggesting its involvement in testicular development. The GH treatment promoted spermatogonial proliferation and accelerated the spermatogenic process in the present catfish. These results, thus, suggest that GH influences the somatic growth and testicular activities depending on the temperature of the rearing water; warmer temperature and longer photoperiod promote testicular steroidogenic and spermatogenic activities in fish. This study has immense practical use in fisheries science. © 2013 Elsevier Inc.

Misra A.K.,Banaras Hindu University | Sharma A.,Banaras Hindu University | Shukla J.B.,Bhabha Group of Institutions
Mathematical and Computer Modelling | Year: 2011

In this paper, a non-linear mathematical model for the effects of awareness programs on the spread of infectious diseases such as flu has been proposed and analyzed. In the modeling process it is assumed that disease spreads due to the contact between susceptibles and infectives only. The growth rate of awareness programs impacting the population is assumed to be proportional to the number of infective individuals. It is further assumed that due to the effect of media, susceptible individuals form a separate class and avoid contact with the infectives. The model is analyzed by using stability theory of differential equations. The model analysis shows that the spread of an infectious disease can be controlled by using awareness programs but the disease remains endemic due to immigration. The simulation analysis of the model confirms the analytical results. © 2010 Elsevier Ltd.

Richa,Banaras Hindu University | Sinha R.P.,Banaras Hindu University | H A Der D.-P.,Friedrich - Alexander - University, Erlangen - Nuremberg
Topics in Current Chemistry | Year: 2015

Solar ultraviolet (UV) radiation, mainly UV-B (280–315 nm), is one of the most potent genotoxic agents that adversely affects living organisms by altering their genomic stability. DNA through its nucleobases has absorption maxima in the UV region and is therefore the main target of the deleterious radiation. The main biological relevance of UV radiation lies in the formation of several cytotoxic and mutagenic DNA lesions such as cyclobutane pyrimidine dimers (CPDs), 6-4 photoproducts (6-4PPs), and their Dewar valence isomers (DEWs), as well as DNA strand breaks. However, to counteract these DNA lesions, organisms have developed a number of highly conserved repair mechanisms such as photoreactivation, excision repair, and mismatch repair (MMR). Photoreactivation involving the enzyme photolyase is the most frequently used repair mechanism in a number of organisms. Excision repair can be classified as base excision repair (BER) and nucleotide excision repair (NER) involving a number of glycosylases and polymerases, respectively. In addition to this, double-strand break repair, SOS response, cell-cycle checkpoints, and programmed cell death (apoptosis) are also operative in various organisms to ensure genomic stability. This review concentrates on the UV-induced DNA damage and the associated repair mechanisms as well as various damage detection methods. ©Springer-Verlag Berlin Heidelberg 2014

Tripathi A.,Banaras Hindu University | Shrivastav T.G.,National Institute of Health and Family Welfare Baba Gang Nath Marg Munirka | Chaube S.K.,Banaras Hindu University
Journal of Assisted Reproduction and Genetics | Year: 2012

Objective: Present study was aimed to determine whether aqueous neem leaf extract (NLE) induces generation of reactive oxygen species (ROS) and apoptosis through mitochondria-mediated pathway in rat oocytes. Design: A controlled prospective study. Setting: Laboratory research setting at Department of Zoology of Banaras Hindu University. Animal(s): Forty eight sexually immature female rats that were 20-30 days of age. Intervention(s): Sexually immature female rats were fed palatable dose of NLE (10 mg/g dry feed palate) for 10 days and then subjected to superovulation induction protocol. Thereafter, rats were euthanized, ovulated cumulus oocyte complexes were collected from oviduct and oocytes were denuded. Main outcome measure(s): Rate of morphological apoptotic changes, measurement of hydrogen peroxide, nitric oxide and cytochrome c concentrations, caspase-9, caspases-3 activities and DNA fragmentation in oocytes. Results: In vivo NLE treatment induced morphological apoptotic changes were associated with increased hydrogen peroxide, nitric oxide and cytochrome c concentrations, caspase-9, caspase-3 activities and DNA fragmentation in oocyte. Conclusion: NLE induces generation of ROS that leads to oocytes apoptosis through mitochondria-mediated pathway. © 2011 Springer Science+Business Media, LLC.

Singh S.P.,Friedrich - Alexander - University, Erlangen - Nuremberg | Hader D.-P.,Friedrich - Alexander - University, Erlangen - Nuremberg | Sinha R.P.,Banaras Hindu University
Ageing Research Reviews | Year: 2010

Cyanobacteria are primitive photosynthetic oxygen-evolving prokaryotes that appeared on the Earth when there was no ozone layer to protect them from damaging ultraviolet radiation (UVR). UVR has both direct and indirect effects on the cyanobacteria due to absorption by biomolecules and UVR-induced oxidative stress, respectively. However, these organisms have developed several lines of mitigation strategies/defense mechanisms such as avoidance, scavenging, screening, repair and programmed cell death to counteract the damaging effects of UVR. This review presents an update on the effects of UVR on cyanobacteria and the defense mechanisms employed by these prokaryotes to withstand UVR stress. In addition, recent developments in the field of molecular biology of UV-absorbing compounds such as mycosporine-like amino acids and scytonemin, are also added and the possible role of programmed cell death, signal perception as well their transduction under UVR stress is being discussed. © 2009 Elsevier Ireland Ltd. All rights reserved.

Lal B.,Banaras Hindu University | Sarang M.K.,Banaras Hindu University | Kumar P.,Rajiv Gandhi University
General and Comparative Endocrinology | Year: 2013

Many hormones are known for their role in the regulation of metabolic activities and somatic growth in fishes. The present study deals with the effects of malathion (an organophosphorous pesticide) on the levels of metabolic hormones that are responsible for promotion of somatic and ovarian growth of the freshwater catfish, Clarias batrachus. Malathion treatment for thirty days drastically reduced the food intake and body weight of fish. These fish also exhibited a great avoidance to food. Exposure of catfish to malathion reduced the levels of thyroxine (T4), triiodothyronine (T3), growth hormone (GH), insulin like growth factor-I (IGF-I), testosterone (T) and estradiol-17β (E2) in a dose dependent manner during all the studied reproductive phases, in general, except that malathion increased the level of GH during the quiescence phase. Significant reduction in muscle and hepatic protein content also occurred in the malathion-treated fish. Malathion exposure induced lipolysis too in the liver and muscle. The results thus support that malathion treatment disrupts the endocrine functions and the olfactory sensation responsible for food intake and gustatory feeding behavior, which ultimately leads to retardation of fish growth. © 2012 Elsevier Inc.

Singh S.P.,Friedrich - Alexander - University, Erlangen - Nuremberg | Klisch M.,Friedrich - Alexander - University, Erlangen - Nuremberg | Sinha R.P.,Banaras Hindu University | Hader D.-P.,Friedrich - Alexander - University, Erlangen - Nuremberg
Genomics | Year: 2010

Mycosporine-like amino acids (MAAs) are a family of more than 20 compounds having absorption maxima between 310 and 362 nm. These compounds are well known for their UV-absorbing/screening role in various organisms and seem to have evolutionary significance. In the present investigation we tested four cyanobacteria, e.g., Anabaena variabilis PCC 7937, Anabaena sp. PCC 7120, Synechocystis sp. PCC 6803 and Synechococcus sp. PCC 6301, for their ability to synthesize MAA and conducted genomic and phylogenetic analysis to identify the possible set of genes that might be involved in the biosynthesis of these compounds. Out of the four investigated species, only A. variabilis PCC 7937 was able to synthesize MAA. Genome mining identified a combination of genes, YP_324358 (predicted DHQ synthase) and YP_324357 (O-methyltransferase), which were present only in A. variabilis PCC 7937 and missing in the other studied cyanobacteria. Phylogenetic analysis revealed that these two genes are transferred from a cyanobacterial donor to dinoflagellates and finally to metazoa by a lateral gene transfer event. All other cyanobacteria, which have these two genes, also had another copy of the DHQ synthase gene. The predicted protein structure for YP_324358 also suggested that this product is different from the chemically characterized DHQ synthase of Aspergillus nidulans contrary to the YP_324879, which was predicted to be similar to the DHQ synthase. The present study provides a first insight into the genes of cyanobacteria involved in MAA biosynthesis and thus widens the field of research for molecular, bioinformatics and phylogenetic analysis of these evolutionary and industrially important compounds. Based on the results we propose that YP_324358 and YP_324357 gene products are involved in the biosynthesis of the common core (deoxygadusol) of all MAAs. © 2009 Elsevier Inc. All rights reserved.

Srivastava A.,Banaras Hindu University | Singh H.K.,National Physical Laboratory India | Awana V.P.S.,National Physical Laboratory India | Srivastava O.N.,Banaras Hindu University
Journal of Alloys and Compounds | Year: 2013

This report underlines the systematic studies of crystalline structure, magnetic and ferroelectric properties of polycrystalline Bi 1-x yLaxPryFeO3 ceramic samples, in which × changes continuously from 0 to 0.2 for y = 0 and y from 0 to 0.2 for × = 0.2. X-ray diffraction (XRD) patterns revealed that La and Pr substitution at Bi site in the ceramic eliminates the usual impurity phases completely. Rietveld refinement of the XRD patterns shows that the crystal structure changes gradually from Rhombohedral (R3c) to Orthorhombic (pbnm) with increasing La and Pr concentration. This transition has significant effects on the multiferroic properties of Bi1 × yLaxPr yFeO3 ceramics. Substantial enhancement in magnetization of Bi1 × yLaxPryFeO3 has been observed and this is found to be correlated with the evolution of structural phase change with doping of Pr in samples having lanthanum concentration of × = 0.2. This leads to the suppression of helical spin order. However, the enhancement in magnetic behavior also takes place due to nanocrystallite nature of Bi1 × yLaxPryFeO3 (x = 0.2, y = 0.05-0.2). For the nanocrystallites having sizes lower than 62 nm, which is the period of spin cycloid, this spin configuration will get destroyed resulting in the enhancement of magnetization. The studies of microstructures employing SEM and TEM revealed that Bi1 × yLa xPryFeO3 consists of nano size grained microstructures. It is also found that dielectric constant and dielectric loss get improved by La and Pr co-substitution. The dielectric constant for x = 0.0, y = 0.0 is 81 which changes to 354 for × = 0.2, y = 0.15 at 100 Hz. Dielectric losses are strongly diminished from 0.960 for × = 0.0, y = 0.0, 0.321 for × = 0.2, y = 0.0 and to 0.20 for × = 0.2, y = 0.05 at 100 Hz. This improvement in dielectric properties is likely due to the changes of lattice parameters and suppression of oxygen vacancies caused by La and Pr co substitution. © 2012 Elsevier B.V. All rights reserved.

Mouli Pandey C.,National Physical Laboratory India | Mouli Pandey C.,Banaras Hindu University | Sumana G.,National Physical Laboratory India | Tiwari I.,Banaras Hindu University
Biosensors and Bioelectronics | Year: 2014

Here, we report a simple and reproducible method for large scale fabrication of novel flower and palm-leaf like 3D cystine microstructures (CMs) with high uniformity having a size of 50μm and 10μm respectively, through a facile aqueous solution route as a function of pH and concentration. In a proof-of-concept study, the 3D CMs have been further explored to fabricate a label-free high-performance electrochemical immunosensor by immobilizing monoclonal antibodies. Electrochemical methods were employed to study the stepwise modification of the system and the electronic transduction for the detection. The fabricated immunosensor design demonstrates high performance with enhanced sensitivity (4.70 cfu ml-1) and linear sensing range from 10 to 3 x 109 cfu ml-1 a long shelf-life (35 days) and high selectivity over other bacterial pathogens. The enhanced performance originates from a novel nanostructuring in which the CMs provide higher surface coverage for the immobilization of antibodies providing excellent electronic/ionic conductivity which result in the enhanced sensitivity. © 2014 Elsevier B.V.

Singh M.P.,Purvanchal University | Singh V.K.,Banaras Hindu University
Cellular and Molecular Biology | Year: 2012

Edible oyster mushroom Pleurotus sapidus was cultivated, on pea pod shell, cauliflower leaves, radish leaves, brassica straw in various combinations of paddy straw. The mushroom failed to grow on these vegetable wastes separately. However, it grew very well on these vegetable wastes when mixed with various combinations of paddy straw as substrate. Total yield and biological efficiency of the mushroom cultivated on substrate containing 20% and 30% vegetable wastes mixed with 70% and 80% (w/w) of paddy straw was found to be better, when compared with yield and efficiency obtained with paddy straw alone (100%). The protein content in the fruit bodies was found to be higher in the mushroom grown on paddy straw mixed with vegetable wastes than that obtained with paddy straw alone. Similarly, six amino acids (Leu, Ile, Val, Thr, Met and Phe) showed a significant increase when the mushroom was grown on a mixed substrate containing both vegetable wastes and paddy straw. On the contrary, the total sugar and reducing sugar content declined in the mushroom grown on the mixture of paddy straw and other wastes, when compared with the results obtained with paddy straw alone. © 2012.

Mishra A.K.,Banaras Hindu University | Shukla E.,Banaras Hindu University | Singh S.S.,Guru Ghasidas University
Protoplasma | Year: 2013

Phylogenetic comparison has been done among the selected heterocystous cyanobacteria belonging to the sections IV and V. The hierarchical cluster analysis based on antibiotics sensitivity showed a distant relationship between the members of Nostocales and Stigonematales. Thus, multiple antibiotic resistance pattern used as marker provide easy, fast, and reliable method for strain discrimination and genetic variability. However, morphological, physiological (both based on principal component analysis) and biochemical analysis grouped true branching cyanobacteria along with the members of section IV. Molecular analysis based on 16S rRNA gene sequences revealed that Hapalosiphon welwitschii and Westiellopsis sp. were grouped in cluster I whereas Scytonema bohnerii, a false branching genera showed a close proximity with Calothrix brevissima in cluster II. Cluster III of clade 2 included Nostoc calcicola and Anabaena oryzae which proved the heterogeneity at the generic level. Cluster IV the largest group of clade 2 based on 16S rRNA gene sequences includes six strains of the genera Nostoc, Anabaena, and Cylindrospermum showing ambiguous evolutionary relationship. In cluster IV, Anabaena sp. and Anabaena doliolum were phylogenetically linked by sharing 99% sequence similarity. Probably, they were of the same genetic makeup but appear differently under the diverse physiological conditions. Section IV showed polyphyletic origin whereas section V showed monophyletic origin. Results suggested that either morphological or physiological or biochemical or molecular attribute is not sufficient to provide true diversity and phylogeny of the cyanobacteria at the generic level and thus, a polyphasic approach would be more appropriate and reliable. © 2012 Springer-Verlag.

Marla S.S.,Govind Ballabh Pant University of Agriculture & Technology | Singh V.K.,Banaras Hindu University
Functional and Integrative Genomics | Year: 2012

Plant Lipoxygenases (LOX) are known to play major role in plant immunity by providing front-line defense against pathogen-induced injury. To verify this, we isolated a full-length OsLOX3 gene and also 12 OsLOX cDNA clones from Oryza sativa indica (cultivar Pusa Basmati 1). We have examined the role played by LOXs in plant development and during attack by blast pathogen Magnaporthe grisea. Gene expression, promoter region analysis, and biochemical and protein structure analysis of isolated OsLOX3 revealed significant homology with LOX super family. Protein sequence comparison of OsLOXs revealed high levels of homology when compared with japonica rice (up to100%) and Arabidopsis (up to 64%). Isolated LOX3 gene and 12 OsLOX cDNAs contained the catalytic LOX domains much required for oxygen binding and synthesis of oxylipins. Amino acid composition, protein secondary structure, and promoter region analysis (with abundance of motifs CGTCA and TGACG) support the role of OsLOX3 gene in providing resistance to diseases in rice plants. OsLOX3 gene expression analysis of root, shoot, flag leaf, and developing and mature seed revealed organ specific patterns during rice plant development and gave evidence to association between tissue location and physiological roles played by individual OsLOXs. Increased defense activity of oxylipins was observed as demonstrated by PCR amplification of OsLOX3 gene and upon inoculation with virulent strains of M. grisea and ectopic application of methyl jasmonate in the injured leaf tissue in adult rice plants. © Springer-Verlag 2012.

Nair P.,Institute of Chemical Technology | Singh B.,Banaras Hindu University | Upadhyay S.N.,Banaras Hindu University | Sharma Y.C.,Banaras Hindu University
Journal of Cleaner Production | Year: 2012

Biodiesel was produced from waste frying oil (WFO) using powdered calcined clamshell (Mereterix mereterix) as a heterogeneous catalyst. Clamshell calcined at 1173 K for 2.5 and 3.5 h showed different catalytic activities. Calcination for 3.5 h resulted in a catalyst of higher activity and reduced transesterification reaction time. The raw and calcined clamshells were characterized by XRD, FTIR, XRF spectroscopy and BET analysis. The XRD peaks showed the characteristics peaks of CaO at 2θ = 37.4, 47.3, and 54.4°. A few high intensity peaks of Ca(OH) 2 at 2θ = 17.9 and 34.1° in the calcined catalyst were also obtained which might have formed due to exposure of CaO with atmospheric air. The used catalyst showed peaks at 8.2 and 10.1° which were characteristic of calcium glyceroxide which was formed due to reaction of calcium oxide and glycerol. Formation of Ca(OH) 2 in the calcined clamshell was also confirmed by FTIR spectra which showed a sharp OH - stretching band. The catalyst was found to comprise principally of calcium (97%) and a few minor elements (Si, Na, Fe, Al, Sr, S, Mn) as analyzed by XRF. The surface area of the calcined clamshell was found to be 2.6 m 2 g -1. The optimum values for various parameters were found to be 3.0 g of catalyst and 25 ml of methanol per 100 ml of oil (6.03:1, methanol to oil molar ratio) at 333 K in 3 h. A high yield (>89%) and conversion (>97%) were obtained on optimization of variables. With the mandatory compulsion by National Biofuel Policy in India to blend 20% of biofuels i.e. bioethanol and biodiesel in the spark ignition and compression ignition engines respectively from 2017 strengthens the applicability of the present study that utilizes waste resources as feedstock and catalyst in the production of a green fuel i.e. biodiesel. © 2012 Elsevier Ltd. All rights reserved.

Ahamad I.,Banaras Hindu University | Prasad R.,Sant Gadge Baba Amravati University | Quraishi M.A.,Banaras Hindu University
Materials Chemistry and Physics | Year: 2010

Three derivatives of 2-[2-(hydrazinecarbonothioyl)hydrazinecarbonyl]benzoic acid (IL1) have been evaluated as new corrosion inhibitors for the corrosion of mild steel in 1 M HCl solutions using weight loss, polarization and electrochemical impedance spectroscopy (EIS) techniques. The adsorption of these compounds has been tested thermodynamically which was found to be of neither a typical physisorption nor a typical chemisorption mode. The thermodynamic functions (such as Ea, ΔH°ads, ΔS°ads and ΔG°ads) of dissolution and adsorption processes have been evaluated. The polarization measurements indicated that the inhibitors are of mixed type. The adsorption of the compounds was found to obey Langmuir's adsorption isotherm. In addition, quantum chemical calculations have been made to correlate inhibition efficiencies determined experimentally. © 2010 Elsevier B.V. All rights reserved.

Sonkar V.K.,Banaras Hindu University | Kulkarni P.P.,Banaras Hindu University | Kulkarni P.P.,Bharati Vidyapeeth Deemed University | Dash D.,Banaras Hindu University
FASEB Journal | Year: 2014

Platelets contribute to 95% of circulating amyloid precursor protein in the body and have widely been employed as a "peripheral" model of neurons in Alzheimer's disease. We sought to analyze the effects of amyloid β (Aβ) on platelets and to understand the underlying molecular mechanism. The Aβ active fragment containing amino acid sequence 25-35 (Aβ25-35; 10-20 μM) was found to induce strong aggregation of human platelets, granule release, and integrin activation, similar to that elicited by physiological agonists. Platelets exposed to Aβ25-35 retracted fibrin clot and displayed augmented adhesion to collagen under arterial shear, reflective of a switch to prothrombotic phenotype. Exposure of platelets to Aβ peptide (20 μM) resulted in a 4.2- and 2.3-fold increase in phosphorylation of myosin light chain (MLC) and MLC phosphatase, respectively, which was reversed by Y27632, an inhibitor of Rho-associated coiled-coil protein kinase (ROCK). Aβ25-35- induced platelet aggregation and clot retraction were also significantly attenuated by Y27632. Consistent with these findings, Aβ25-35 elicited a significant rise in the level of RhoA-GTP in platelets. Platelets pretreated with reverse-sequenced Aβ fragment (Aβ35-25) and untreated resting platelets served as controls. We conclude that Aβ induces cellular activation through RhoA-dependent modulation of actomyosin, and hence, RhoA could be a potential therapeutic target in Alzheimer's disease and cerebral amyloid angiopathy. © FASEB.

Kumar S.,Banaras Hindu University | Li M.S.,Polish Academy of Sciences
Physics Reports | Year: 2010

Recent advances in single molecule experiments have raised many challenges. These challenges can be met by a proper understanding of the inter- and intra-molecular interactions in the framework of physics followed by suitable theoretical models substantiated by extensive numerical simulations. In this review, we briefly discuss experimental, theoretical and numerical techniques used to examine the dynamics of biomolecules under the application of external mechanical force. We focus on issues which require special attention: the relationship between the mechanical stability of a protein and the secondary structure of its native conformation, the dependence of the free energy landscape on the pulling direction and secondary structure content, unfolding of a protein through a pore, protein re-folding under quenched force etc. We pay special attention to a single stranded DNA, where the force-extension curve shows a multi-step plateau for the chain made up of adenine while poly-thymine exhibits entropic response only. There are many interesting predictions related to unzipping of double stranded DNA e.g. re-entrance in the force-temperature phase diagram, existence of an "Eye-phase", effects of random disorder etc. based on model studies which require further investigation. We will also discuss cases where the theoretical descriptions of the models fail to explain the experimentally observed behavior and when further refinement is needed in order to describe the outcomes of experiments. Finally we suggest certain experimental protocols to observe theoretical predictions in vitro. © 2009 Elsevier B.V.

Singh R.K.,Central University of Bihar | Singh A.K.,Banaras Hindu University
Acta Mechanica Sinica/Lixue Xuebao | Year: 2012

In the present paper, we have considered the steady fully developed laminar natural convective flow in open ended vertical concentric annuli in the presence of a radial magnetic field. The induced magnetic field produced by the motion of an electrically conducting fluid is taken into account. The transport equations concerned with the considered model are first recast in the non-dimensional form and then unified analytical solutions for the velocity, induced magnetic field and temperature field are obtained for the cases of isothermal and constant heat flux on the inner cylinder of concentric annuli. The effects of the various physical parameters appearing into the model are demonstrated through graphs and tables. It is found that the magnitude of maximum value of the fluid velocity as well as induced magnetic field is greater in the case of isothermal condition compared with the constant heat flux case when the gap between the cylinders is less or equal to 1.70 times the radius of inner cylinder, while reverse trend occurs when the gap between the cylinders is greater than 1.71 times the radius of inner cylinder. These fields are almost the same when the gap between the cylinders is equal to 1.71 times the radius of inner cylinder for both the cases. It is also found that as the Hartmann number increases, there is a flattening tendency for both the velocity and the induced magnetic field. The influence of the induced magnetic field is to increase the velocity profiles. © The Chinese Society of Theoretical and Applied Mechanics and Springer-Verlag Berlin Heidelberg 2012.

Bhuin T.,University of Burdwan | Roy J.K.,Banaras Hindu University
Experimental Cell Research | Year: 2014

Vesicular/membrane trafficking essentially regulates the compartmentalization and abundance of proteins within the cells and contributes in many signalling pathways. This membrane transport in eukaryotic cells is a complex process regulated by a large and diverse array of proteins. A large group of monomeric small GTPases; the Rabs are essential components of this membrane trafficking route. Most of the Rabs are ubiquitously expressed proteins and have been implicated in vesicle formation, vesicle motility/delivery along cytoskeleton elements and docking/fusion at target membranes through the recruitment of effectors. Functional impairments of Rabs affecting transport pathways manifest different diseases. Rab functions are accompanied by cyclical activation and inactivation of GTP-bound and GDP-bound forms between the cytosol and membranes which is regulated by upstream regulators. Rab proteins are characterized by their distinct sub-cellular localization and regulate a wide variety of endocytic, transcytic and exocytic transport pathways. Mutations of Rabs affect cell growth, motility and other biological processes. © 2014 Elsevier Inc.

Ahamad I.,Banaras Hindu University | Prasad R.,Sant Gadge Baba Amravati University | Quraishi M.A.,Banaras Hindu University
Corrosion Science | Year: 2010

Inhibition of mild steel corrosion in 1 M HCl solution by Pheniramine drug was studied using weight loss, electrochemical impedance spectroscopy, linear polarization resistance, and potentiodynamic polarization measurements. The values of activation energy (Ea) and different thermodynamic parameters such as adsorption equilibrium constant (Kads), free energy of adsorption (Δ Gads °), adsorption enthalpy (Δ Hads °) and adsorption entropy (Δ Sads °) were calculated and discussed. The adsorption process of studied drug on mild steel surface obeys the Langmuir adsorption isotherm. Potentiodynamic polarization measurements showed that Pheniramine is mixed-type inhibitor. Further, theoretical calculations were carried out and relations between computed parameters and experimental inhibition efficiency were discussed. © 2010 Elsevier Ltd. All rights reserved.

Mohanta K.,Banaras Hindu University | Bhargava P.,Indian Institute of Technology Bombay
Journal of the American Ceramic Society | Year: 2010

Fused silica slurries with a maximum ceramic loading of 70 vol% were prepared using aqueous premixes with egg white (0.5-1.5 vol%) and/or sucrose (5-20 vol%). The egg white and sucrose content in the premix were optimized to obtain a shear-thinning slurry. Observation indicated the existence of an optimum composition (Si70-(S+E)10-E10), for which slurry viscosity was minimum. Thermal analysis confirms the interaction between egg white and sucrose molecules, which influence interparticle interaction and slurry properties. Green samples cast from optimum slurry composition exhibited the highest mechanical properties. Linear drying and sintering shrinkage of samples were 0.5% and 1.0%, respectively. © 2010 The American Ceramic Society.

The intracellular redox environment plays an important role in the maintenance of proper cellular homeostasis and functions. Disturbances in redox equilibrium of cells result in pro-inflammatory conditions, and these inflammatory conditions can induce carcinogenesis or increase the malignant potential of the tumor. Oxidative stress or tissue damage can trigger toll-like receptor (TLR) family of receptors that are involved in altering the innate immune system. The present study was aimed at evaluating the level of oxidative damage markers in breast diseases by measuring the 8-hydroxydeoxyguanosine (8-OHdG), protein carbonyl (PC), malondialdehyde (MDA), and total antioxidant status (TAS) alterations in relation to expression of TLR-9. A significant increase in the level of oxidative damage markers was observed in breast carcinoma patients in comparison to benign and normal controls, which was accompanied by a significant decrease in TAS and expression of TLR-9 concentrations. 8-OHdG, PC, and MDA were negatively correlated with expression of TLR-9 and TAS levels. Altered levels of biomarkers of oxidative stress and TLR-9 among the malignant, benign, and controls suggest a correlation of oxidative stress and TLR signaling in the progression of disease in breast carcinoma patients. Receiver operating characteristic analysis depicts that expression of TLR-9 is a good indicator for distinguishing cancer patients from benign and normal controls. High accuracy, specificity, and sensitivity of oxidative stress markers and expression of TLR-9 can be used as discriminatory marker/s for efficient diagnosis.

Ramakrishnan T.V.,Indian Institute of Science | Ramakrishnan T.V.,Banaras Hindu University
Annual Review of Condensed Matter Physics | Year: 2016

This is an account of a professional life in the field that was generally known as solid-state physics when I started working in it; India and the United States of America are the countries in which this life was largely played out. My attempts to understand various things in condensed matter physics, and efforts to put together people and activities in India in this field, are mainly the story. © Copyright 2016 by Annual Reviews. All rights reserved.

Chaurasia R.N.,Banaras Hindu University
BMJ case reports | Year: 2013

Cysticercosis in humans is caused by Taenia solium larvae infestation. Oral cysticercosis is a rare condition and is challenging to diagnose. We present a case of masseter cysticercosis in a young woman who presented with painful recurrent cheek swelling. Diagnosis confirmed it after neuroimaging and histopathological examination of the excised lesion from masseter muscle.

Cervical cancer is a major cause of morbidity and mortality in women worldwide. In recent years, benzothiazole analogues have attracted considerable attention in anticancer research. Therefore, in this study, the earlier reported amide series of benzothiazole derivatives were investigated for their antiproliferative activity. The activity of amide derivatives was evaluated using the 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, flow cytometric analysis, apoptosis assay, and DNA fragmentation on two human cervical cancer cell lines: SiHa and C33-A. The data reported from this investigation indicated that benzothiazole derivatives show pronounced cytotoxicity in the HPV16-positive SiHa cells compared with HPV-negative C-33A cells. The in-vitro cytotoxicity of the compounds on the HEK-293 noncancer cell line was evaluated to establish selectivity. Cells treated with benzothiazole derivatives showed prominent morphological features as evidenced by cell shrinkage, membrane blebbing, apoptotic nuclei, and DNA fragmentation. The benzothiazole derivatives show accumulation of cells in the sub-G1 and S-phase of the cell cycle in SiHa and C33-A, respectively. In addition, these derivatives exert their beneficial effect by inducing apoptosis, in the chemoprevention of cervical cancer cells, and were further ascertained using a DNA fragmentation assay. The compounds studied showed potent cytotoxic and apoptotic properties against SiHa and C33-A cancer cell lines and thus represent an excellent starting point for further optimization of therapeutically effective anticancer drugs. Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved.

Yadav T.P.,University of Liverpool | Yadav T.P.,Banaras Hindu University | Srivastava O.N.,Banaras Hindu University
Ceramics International | Year: 2012

We have synthesized pure nanocrystalline CeO 2 powders of nearly spherical shape using high-energy attritor ball mill. Milling parameters such as the milling speed of 400 rpm, ball to powder ratio (40:1), milling time (30 h) and water cooled media were determined to be suitable for synthesizing nanosize (∼10 nm) powders of CeO 2. The powders after milling for various durations (up-to 50 h) were characterized by X-ray Diffraction, Scanning Electron Microscopy, Energy-dispersive X-ray Spectrometry and Transmission Electron Microscopy. An average particle size of 10 nm was obtained at 30 h milling, after which the particle agglomeration started, and a mixture of nanocrystalline and amorphous phase was observed after 50 h milling. © 2012 Elsevier Ltd and Techna Group S.r.l. All rights reserved.

Singh R.P.,Banaras Hindu University
Reviews of Environmental Contamination and Toxicology | Year: 2011

As a result of rapid urbanization, industrialization, and uncontrolled population increase, waste management has become a worldwide problem. In the 2001 census, the urban population of India comprised 285 millions, which accounted for 27% of the total population of the country. The share of urban population has increased from 19.9% in the year 1971 to 27.8% in the year 2001 (Vaidya 2009). The decadal growth from 1991 to 2001 of the urban population was 31.2%. One of the main reasons for increasing urbanization is the migration of rural populations to urban centers for employment. The unprecedented growth of this urban population has put tremendous pressure on the quality of life regarding housing, water, and power supply, and water, air, and soil quality deterioration. A decline in environmental quality from waste generation in these urban centers, especially solid waste, is of major and growing concern. © 2011 Springer Science+Business Media, LLC.

Rab11, an evolutionary conserved, ubiquitously expressed subfamily of small monomeric GTPase has been known to regulate diverse cellular and developmental events, by regulating the exocytotic and transcytotic events inside the cell. Our studies show that Rab11 regulates Drosophila adult myogenesis by controlling proliferation and differentiation of the Adult muscle precursors (AMPs). Blocking Rab11 in the AMPs, which fuse to form the Indirect Flight Muscles (IFMs) of fly, renders flies completely flightless and non-viable. The indirect flight musculature, comprising of the differentially patterned dorsal longitudinal muscles (DLMs) and dorsal ventral muscles (DVMs), is affected to different extents. Abrogating or knocking down normal Rab11 function results in severely disrupted IFMs. DLMs forming from larval templates are reduced in number along with a significant reduction in their fibre size. The de novo developing DVMs are frequently absent. The DLMs in Rab11 hypomorphs are highly reduced, showing as a small constricted mass in one half of the thorax. Further, Rab11 function is essential for growth of these muscles during later half of adult myogenesis, as down regulation of Rab11 in IFMs results in degenerated muscles and broken fibres. Finally, we show that loss of Rab11 activity in the AMPs result in acquisition of migratory characteristic of myoblast as they show cellular protrusion at their polar ends accompanied with loss of cell-cell contacts. Our data provide the first evidence of a trafficking protein playing an indispensable role in regulating early stages of adult muscle development.

Yadav R.K.,Banaras Hindu University | Khare A.,Indian Institute of Science | Mandal B.P.,Banaras Hindu University
Annals of Physics | Year: 2013

The scattering amplitude for a recently discovered exactly solvable shape invariant potential, which is isospectral to the generalized Pöschl-Teller potential, is calculated explicitly by considering the asymptotic behavior of the X1 Jacobi exceptional polynomials associated with this system. © 2013 Elsevier Inc.

Yadav R.K.,Banaras Hindu University | Khare A.,Indian Institute of Science | Mandal B.P.,Banaras Hindu University
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2013

We consider the recently discovered, one parameter family of exactly solvable shape invariant potentials which are isospectral to the generalized Pöschl-Teller potential. By explicitly considering the asymptotic behavior of the Xm Jacobi polynomials associated with this system (m=1, 2, 3, ...), the scattering amplitude for the one parameter family of potentials is calculated explicitly. © 2013 Elsevier B.V.

Shukla U.K.,Banaras Hindu University | Ram P.,Banaras Hindu University
Environmental Monitoring and Assessment | Year: 2011

The hydrogeochemical parameters for groundwater samples of the Varanasi area, a fast-urbanizing region in India, were studied to evaluate the major ion chemistry, weathering and solute acquisition processes controlling water composition, and suitability of water quality for domestic and irrigation uses. Sixty-eight groundwater samples were collected randomly from dug wells and hand pumps in the urban Varanasi area and analyzed for various chemical parameters. Geologically, the study area comprises Quaternary alluvium made up of an alternating succession of clay, silty clay, and sand deposits. The Total dissolved solids classification reveals that except two locations, the groundwater samples are desirable for drinking, and all are useful for irrigation purposes. The cationic and anionic concentrations indicated that the majority of the groundwater samples belong to the order of Na > Ca > Mg > K and HCO3 > Cl > SO4 types, respectively. Geochemical classification of groundwater based on the Chadha rectangular diagram shows that the majority (81%) of groundwater samples belong to the calcium-bicarbonate type. The HCO3/ (HCO3 + SO 4) ratio (0.87) indicates mostly carbonic acid weathering process due to presence of kankar carbonate mixed with clay/fine sand. The high nitrate concentration (>45 mg/l) of about 18% of the groundwater samples may be due to the local domestic sewage, leakage of septic tanks, and improper management of sanitary landfills. In general, the calculated values of sodium adsorption ratio, percent sodium, residual sodium carbonate, and permeability index indicate good to permissible use of water for irrigation, and only a few locations demand remedial measures for better crop yields. © 2010 Springer Science+Business Media B.V.

Paital B.,Banaras Hindu University | Paital B.,Indian Institute of Science
Ecotoxicology and Environmental Safety | Year: 2013

Many fishes are exposed to air in their natural habitat or during their commercial handling. In natural habitat or during commercial handling, the cat fish Heteropneustes fossilis is exposed to air for >24h. Data on its oxidative metabolism in the above condition are not available. Oxidative stress (OS) indices (lipid and protein oxidation), toxic reactive oxygen species (ROS: H2O2) generation, antioxidative status (levels of superoxide dismutase, catalase, glutathione peroxidase and reductase, ascorbic acid and non-protein sulfhydryl) and activities of electron transport chain (ETC) enzymes (complex I-IV) were investigated in brain tissue of H. fossilis under air exposure condition (0, 3, 6, 12 and 18h at 25°C). Decreased activities of antioxidant (except catalase) and ETC enzymes (except complex II) with increased H2O2 and OS levels were observed in the tissue under water deprivation condition. Positive correlation was observed for complex II activity and non-protein thiol groups with time period of air exposure. The critical time period to induce OS and to reduce most of the studied antioxidant level in brain was found to be 3-6h air exposure. The data can be useful to minimize the stress generated during commercial handling of the live fishes those exposed to air in general and H. fossilis in particular. © 2013 Elsevier Inc.

Sonkar G.K.,Banaras Hindu University
Saudi journal of kidney diseases and transplantation : an official publication of the Saudi Center for Organ Transplantation, Saudi Arabia | Year: 2011

Immunoglobulins (Ig) and complement, which are components of humoral immunity, are supposed to play a role in renal transplant rejection. The present study was undertaken to study the level of complement C3, C4 and IgG, A and M in patients with chronic renal failure (CRF) and in those with renal transplant rejection (Tx Rej) as well as stable transplant recipients (Tx Stb) and normal healthy controls (NHC) in order to assess their role in transplant rejection and to correlate them with histopathological findings. The mean level of C3 and C4 in the CRF, Tx Rej and Tx Stb groups was not significantly different from the NHC group (P > 0.05). The mean level of C3 in the Tx Rej group was not different from that in the Tx Stb group. However, the C4 level was significantly reduced in the Tx Rej group when compared with the Tx Stb group (P < 0.05). There was no histopathological correlation between C3 levels and acute cellular rejection (ACR) or chronic allograft nephropathy (CAN); however, C4 levels were reduced in about 50% of the cases with CAN. The mean serum IgG level was significantly reduced in patients with CRF and transplant recipients as compared with NHC. The serum IgA level was also significantly reduced in Tx Rej cases. Correlation of serum IgA with histopathology in cases with rejection showed that in ACR, a lower mean level of IgA was seen as compared with that seen in cases with CAN. The serum IgM level was significantly higher in the Tx Rej group as compared with the Tx Stb group. There was no significant correlation between serum IgM levels and renal histopathology in patients with ACR and CAN. The C3 level showed a significant positive correlation with IgG (r = +0.50, P < 0.05) in the Tx Stb group. This study shows that cell-mediated immunity is the main cause of rejection in both ACR and CAN while humoral immunity is also involved along with cellular immunity in some cases with CAN.

Goyal N.K.,Banaras Hindu University
Saudi journal of kidney diseases and transplantation : an official publication of the Saudi Center for Organ Transplantation, Saudi Arabia | Year: 2010

To compare the accuracy of artificial neural network (ANN) analysis and multi-variate regression analysis (MVRA) for renal stone fragmentation by extracorporeal shock wave lithotripsy (ESWL). A total of 276 patients with renal calculus were treated by ESWL during December 2001 to December 2006. Of them, the data of 196 patients were used for training the ANN. The predictability of trained ANN was tested on 80 subsequent patients. The input data include age of patient, stone size, stone burden, number of sittings and urinary pH. The output values (predicted values) were number of shocks and shock power. Of these 80 patients, the input was analyzed and output was also calculated by MVRA. The output values (predicted values) from both the methods were compared and the results were drawn. The predicted and observed values of shock power and number of shocks were compared using 1:1 slope line. The results were calculated as coefficient of correlation (COC) (r2 ). For prediction of power, the MVRA COC was 0.0195 and ANN COC was 0.8343. For prediction of number of shocks, the MVRA COC was 0.5726 and ANN COC was 0.9329. In conclusion, ANN gives better COC than MVRA, hence could be a better tool to analyze the optimum renal stone fragmentation by ESWL.

Singh K.,Banaras Hindu University
Reproductive sciences (Thousand Oaks, Calif.) | Year: 2011

Infertility is a major reproductive health problem affecting 10% to 15% of couples, with approximately equal contributions. Spermatogenesis is a dynamic and multistep process of male germ cell proliferation and differentiation by which spermatozoa are produced from primordial germ cells. The causes of spermatogenic defects in infertile men are multifactorial and many environmental, nutritional, behavioral and genetic factors affect male infertility. In most of the infertile cases, the underlying mechanisms remain obscure. Genomics and proteomics offer new tools for better understanding the genetics of male infertility. The current review provides insights into the plausible chromosomal, genetic and epigenetic alterations, which may result into infertile phenotype.

This study aimed to assess correlation of urinary monocytic chemoattractant protein-1 (UMCP-1) with severity of lupus nephritis and its role as predictor of outcome. Twenty patients with lupus nephritis flare were included in the study. Ten patients in each group of stable systemic lupus erythematosus and non-renal flare were taken as controls. Biopsy was done to define lupus nephritis stage. UMCP-1 levels were measured in all patients at the time of entry and at four and eight weeks of follow-up. Mild, moderate and severe lupus nephritis flare was noted in one, five and 15 patients, respectively. UMCP-1 levels were high in patients with severe lupus nephritis flare (2.74 ± 0.95 ng/mg creatinine) as compared to patients with moderate (1.43 ± 0.46 ng/mg creatinine) and mild lupus nephritis flare (0.76 ± 0.57 ng/mg creatinine) (P = 0.0093). Baseline mean UMCP-1 levels in lupus nephritis flare, non-renal flare and stable SLE patients were 2.32 ± 1.06, 0.171 ± 0.03 and 0.213 ± 0.026 ng/mg creatinine, respectively. The difference among the three groups was very significant (P < 0.001). Also, mean UMCP-1 levels correlated significantly with severity of lupus nephritis class (P = 0.0358). During follow-up, 15 patients achieved complete or partial remission, and in these patients mean UMCP-1 levels had significant decline at eight weeks (P < 0.0001). However, mean UMCP-1 levels in the remaining five non-responders did not show significant changes at four and eight weeks (P = 0.4858). Mean UMCP-1 levels were significantly higher in the lupus nephritis flare group as compared to non-renal flare and stable patients. Baseline mean UMCP-1 levels significantly correlated with both lupus nephritis class and severity of lupus nephritis flare, hence UMCP-1 could be used as a non-invasive marker for the judgement of lupus flare and lupus nephritis class.

Background/objectives:Choline is an essential nutrient involved in one-carbon metabolism, but its role in mechanisms underlying meiotic non-disjunction is poorly known. The relationship between folate-homocysteine metabolic pathway gene polymorphism and Down syndrome (DS) risk has been widely analyzed, but there are limited reports on its correlation with choline metabolism. In the present case–control association study, we investigated the relationship of three single-nucleotide polymorphisms (SNPs) (phosphatidylethanolamine N-methyltransferase (PEMT) rs12325817, choline dehydrogenase (CHDH) rs12676 and homocysteine methyltransferase (BHMT) rs3733890) of choline metabolism with risk for DS.Subject/methods:Genotyping of 228 mothers of a down syndrome child (DSM) and 200 control mothers (CMs) for all SNPs was performed by PCR coupled with restriction fragment length polymorphism method.Results:A significantly increased risk for BHMT +742AA genotype with an odds ratio of 4.96 (95% confidence interval (CI): 1.66–14.88, P=0.0036) was observed. For PEMT rs12325817 and CHDH rs12676, no significant difference in allelic and genotypic frequencies was observed. In genotypic combination analysis considering PEMT −744GG/CHDH +432GG/BHMT +742GG as the reference combination, PEMT −744GC/CHDH +432GG/BHMT +742GG genotypic combination was significantly higher in DSM compared with that in CMs with an odds ratio of 2.061 (95% CI: 1.10–3.86, P=0.0342). We also observed an epistatic interaction between methylenetetrahydrofolate reductase (MTHFR) rs1801133 and choline metabolic pathway gene variants.Conclusions:Our findings indicate impaired choline metabolism showing a greater risk for DS, especially in a population associated with homocysteine-folate impairment. Further studies are required to confirm our findings.European Journal of Clinical Nutrition advance online publication, 28 September 2016; doi:10.1038/ejcn.2016.190. © 2016 Macmillan Publishers Limited, part of Springer Nature.

Mishra O.P.,Banaras Hindu University
Journal of tropical pediatrics | Year: 2013

The objective of the present study was to find out the predictors of relapse. One hundred fifty children with a first episode of idiopathic nephrotic syndrome were followed for 12 months after initial treatment. Sixty-one (40.7%) children had no relapse, and 89 (59.3%) had relapses. A significantly higher proportion of children with disease onset between 1 and 3 years were relapsers in comparison with those with disease onset at 4-6 (p < 0.03) and 7-13 (p < 0.001) years. Risk of relapse was 2.99 times higher in this 1-3 year age-group as compared with patients aged >6 years (p = 0.001). Children responding between 1 and 2 weeks after start of treatment had a 0.423 times lesser risk of relapse than those who responded after 4 weeks (p = 0.023). Relapsers had significantly higher incidence of infection at relapse than at other time points (p < 0.001). Onset of disease in younger age and delayed response to prednisolone therapy were found as significant predictors for relapse.

Sahu D.R.,Banaras Hindu University | Yao J.C.,National Sun Yat - sen University
Journal of Global Optimization | Year: 2011

It is known, by Rockafellar (SIAM J Control Optim 14:877-898, 1976), that the proximal point algorithm (PPA) converges weakly to a zero of a maximal monotone operator in a Hilbert space, but it fails to converge strongly. Lehdili and Moudafi (Optimization 37:239-252, 1996) introduced the new prox-Tikhonov regularization method for PPA to generate a strongly convergent sequence and established a convergence property for it by using the technique of variational distance in the same space setting. In this paper, the prox-Tikhonov regularization method for the proximal point algorithm of finding a zero for an accretive operator in the framework of Banach space is proposed. Conditions which guarantee the strong convergence of this algorithm to a particular element of the solution set is provided. An inexact variant of this method with error sequence is also discussed. © 2011 Springer Science+Business Media, LLC.

Mishra B.,Banaras Hindu University
Current drug targets | Year: 2015

Drug nanocrystals have been studied since the 1990s and there are already six therapeutic nanocrystal products on market and many more in clinical trials. Nanocrystals are encapsulating-carrier free nanoparticles wherein 100% drug loading could be achieved. This signifies that nanocrystals, among other nanoparticulate products, could be more easily manufactured even at the initial formulation development stages to evaluate the effect of size reduction on the bioavailability of drugs. Additionally, a drug nanocrystal is considered not as a generic product but as a "new drug" by FDA. Process characterization, equipment choice, robust formulation and stability are discussed as four basic prerequisites for formulation development and scale-up of drug nanocrystals. The fast growing and relatively superior market profile of nanocrystals amongst other nanoparticle systems is due to their rational formulation design and production simplicity. In this emerging scenario, keeping an eye on the four basic prerequisites can further improve the success of drug nanocrystals.

Pandey A.,Banaras Hindu University
Skinmed | Year: 2010

Infantile hemangioma is a common disease. Steroids have been used for its treatment; however, intralesional steroids cause pain and other problems. A treatment modality that can avoid these problems is desirable. The authors evaluated the role of topical steroids as an alternative to intralesional steroids in the treatment of superficial hemangioma. Inclusion criteria were <2 superficial type ofhemangiomas <5 cm. The topical steroid mometasone furoate was applied twice daily. Intralesional triamcinolone acetonide was injected at monthly intervals using a 24-gauge needle at doses of 1 to 2 mg/kg. Forty-five (86.5%) patients responded to treatment with the topical steroids, of which 50% had excellent and 36.5% had good response. In the intralesional group, the response rate was 95.7%, of which 63.8% had excellent and 31.9% had good response. Complications in the topical steroid group were mild itching and irritation (19.2%) and hypopigmentation (7.6%). Complications in the intralesional group were pain (100%), bleeding (17%), infection (17%), cutaneous atrophy (8.5%), cushingoid facies (2.1%), and growth retardation (2.1%). Topical steroids are a reasonably good alternative to intralesional steroids as an initial choice for treating superficial hemangioma.

Agrawal D.,Banaras Hindu University
The Indian journal of chest diseases & allied sciences | Year: 2012

Pulmonary blastoma is a rare but aggressive malignancy of the lung comprising epithelial and mesenchymal elements that resemble fetal lung tissue. This report described a case of an 18-year-old male who presented with cough and weight loss for a month. Computed tomography (CT) of the thorax revealed a large mass with mixed solid and cystic lesions on the right side of chest along with pleural effusion and mediastinal lymphadenopathy. Massive debulking was performed followed by chemotherapy. A biphasic pulmonary blastoma was diagnosed on histopathology.

Mixed metal-hexacyanoferrates (MHCF) have shown promising applications for technological development particularly in energy storage technologies, ferromagnetic materials, and electrode materials. However, the challenge of controlling their chemical synthesis, solubility, polycrystallinity and nanogeometry have restricted the practical implementation of MHCF in commercial designs. Further, MHCFs have shown potential as peroxidase mimetics. There is still challenging demand to enhance the catalytic efficiency of such materials to the equivalent of biocatalytic activity thereby allowing the precise control of the mimetic character and ultimately leading to the development of new materials as powerful peroxidases i.e. Horseradish peroxidase (HRP) replacement during enzyme and immuno-sensors development. We report herein a new process that allows the controlled synthesis of biocompatible mixed MHCF nanoparticles with a variety of transition metal ions. The resulting polycrystalline mixed MHCF shows enhanced catalytic efficiency to hydrogen peroxide (H2O2) as compared to that of polycrystalline Prussian blue (PB) made under similar conditions with significant increase in catalytic efficiency as a function of respective hetero-transition metal ion of mixed FeHCF in the order of FeHCF < Mn-FeHCF < Ni-FeHCF < Cu-FeHCF justifying as perfect peroxidase replacement.

Kumar S.,Banaras Hindu University
Indian journal of pathology & microbiology | Year: 2010

CONTEXT: Von Willebrand disease is the most common inherited bleeding disorder with a prevalence of approximately 1% in the general population. Studies available from India are limited, showing a prevalence of approximately 10% of vWD amongst inherited bleeding disorders. AIMS: This study aims to know the prevalence and subtypes of vWD in patients presenting with various bleeding manifestations to university hospital. SETTINGS AND DESIGN: We investigated 840 patients presenting with bleeding manifestations in the period from August 2004 to August 2008 for bleeding disorders. MATERIALS AND METHODS: Tests performed for the diagnosis of vWD included platelet count, bleeding time (BT), prothrombin time (PT), activated partial thromboplastin time (APTT), Factor VIII:C assay, von Willebrand Factor Antigen assay and Ristocetin-induced platelet aggregation. RESULTS: Amongst 840 patients, 230 (27.38%) had inherited bleeding disorder. Out of these, 40 (17.39%) patients were identified as vWD. Type 1 in 17 (42.5%), Type 2 in 11 (27.5%) and Type 3 vWD was present in 12 (30.0%) patients. Patients' age ranged from five months to 45 years, with 17 males and 23 females. Positive family history was seen in 12 patients (30%). Muco-cutaneous bleeding was the most common presentation. Menorrhagia was present in 100% women of reproductive age group, and hemarthrosis was seen in two male patients. CONCLUSIONS: We felt that Type I vWD with infrequent and mild bleeding episodes remain undiagnosed either because of unawareness of the disease in society or due to paucity of diagnostic facilities available in our country. Therefore, an awareness program along with enhancement of diagnostic facilities for vWD is required in our country to identify these patients for proper management thus avoiding hemorrhagic complications.

Abhilash P.C.,Banaras Hindu University | Powell J.R.,University of Western Sydney | Singh H.B.,Banaras Hindu University | Singh B.K.,University of Western Sydney
Trends in Biotechnology | Year: 2012

Soil remediation that revitalizes degraded or contaminated land while simultaneously contributing to biomass biofuel production and carbon sequestration is an attractive strategy to meet the food and energy requirements of the burgeoning world population. As a result, plant-based remediation approaches have been gaining in popularity. The drawbacks of phytoremediation, particularly those associated with low productivity and limitations to the use of contaminant-containing biomass, could be addressed through novel biotechnological approaches that harness recent advances in our understanding of chemical interactions between plants and microorganisms in the rhizosphere and within plant tissues. This opinion article highlights three promising approaches that provide environmental and economic benefits of bioremediation: transgenics, low-input 'designer' plants and nanotechnology. © 2012 Elsevier Ltd.

Singh A.,Udai Pratap Autonomous College | Ahamad I.,Banaras Hindu University | Singh V.K.,Udai Pratap Autonomous College | Quraishi M.A.,Banaras Hindu University
Journal of Solid State Electrochemistry | Year: 2011

The inhibition of the corrosion of mild steel in hydrochloric acid solution by the seed extract of Karanj (Pongamia pinnata) has been studied using weight loss, electrochemical impedance spectroscopy, potentiodynamic polarization, and linear polarization techniques. Inhibition was found to increase with increasing concentration of the extract. The effect of temperature, immersion time, and acid concentration on the corrosion behavior of mild steel in 1 M HCl with addition of extract was also studied. The adsorption of the extract on the mild steel surface obeyed the Langmuir adsorption isotherm. Values of inhibition efficiency calculated from weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopy are in good agreement. Polarization curves showed that Karanj (P. pinnata) seed extract behaves as a mixed-type inhibitor in hydrochloric acid. The activation energy as well as other thermodynamic parameters for the inhibition process was calculated. The adsorbed film on mild steel surface containing Karanj (P. pinnata) seed extract inhibitor was also measured by Fourier transform infrared spectroscopy. The results obtained showed that the seed extract of Karanj (P. pinnata) could serve as an effective inhibitor of the corrosion of mild steel in hydrochloric acid media. © 2010 Springer-Verlag.

Gupta V.,Banaras Hindu University
Advances in Experimental Medicine and Biology | Year: 2010

Dyskeratosis congenita (DC) is an inheritable bone marrow failure syndrome characterized by reticulated hyperpigmentation, dystrophic nails and oral leukoplakia. Another name for the condition is Zinsser-Cole-Engman syndrome. Hematologic manifestations usually do not appear in childhood but later in early adulthood. Patients are also prone to carcinomas, particularly of the head and neck. The disease has X-linked or autosomal dominant/recessive inheritance. Early childhood variants (Hoyeraal-Hreidarsson syndrome) are associated with immunological abnormalities in the form of low T- and B-cell numbers. Four genes, namely DKC1 (codes for dyskerin), TERC and TERT (code for telomerase) and NOP10, have been implicated in the pathogenesis; the short telomeres provide a marker for genetic linkage studies. Androgens, with or without granulocyte colony stimulating factor, have been tried in the treatment of the conditions with variable results. Stem cell transplantation from matched sibling donor is currently the treatment of choice. It requires modified nonmyeloablative conditioning protocols, since the patients with DC are prone to pulmonary and hepatic complications. © 2010 Landes Bioscience and Springer Science+Business Media.

Bhadauria B.S.,Banaras Hindu University | Agarwal S.,Banaras Hindu University
Transport in Porous Media | Year: 2011

The effect of local thermal non-equilibrium on linear and non-linear thermal instability in a horizontal porous medium saturated by a nanofluid has been investigated analytically. The Brinkman Model has been used for porous medium, while nanofluid incorporates the effect of Brownian motion along with thermophoresis. A three-temperature model has been used for the effect of local thermal non-equilibrium among the particle, fluid, and solid-matrix phases. The linear stability is based on normal mode technique, while for nonlinear analysis, a minimal representation of the truncated Fourier series analysis involving only two terms has been used. The critical conditions for the onset of convection and the heat and mass transfer across the porous layer have been obtained numerically. © 2011 Springer Science+Business Media B.V.

Singh R.N.,Banaras Hindu University | Awasthi R.,Banaras Hindu University
Catalysis Science and Technology | Year: 2011

Graphene nanosheets (GNS) were synthesized by the NaBH4 reduction of freshly prepared graphite oxide and utilized as a catalyst support of palladium nanoparticles for the electrooxidation of ethanol and methanol. Home-made GNS were characterized by Raman spectroscopy and XRD. The study has shown that Pd nanoparticles dispersed on GNS were highly active for the electrooxidation of ethanol and methanol in 1 M KOH. It is observed that Pd nanoparticles dispersed on GNS are more active compared to those dispersed on nanocarbon particles (NC) or multiwall carbon nanotubes (MWCNTs) for ethanol/methanol electrooxidation under similar experimental conditions. The enhanced electrochemical activity of Pd/GNS toward alcohol oxidation can be ascribed to the greatly enhanced electrochemical active surface area of Pd nanoparticles on the GNS support. © 2011 The Royal Society of Chemistry.

Tripathi S.,Banaras Hindu University | Tripathi B.D.,Banaras Hindu University
Bioresource Technology | Year: 2011

The present work was aimed at studying the efficiency of the combined process of biofiltration with ozonation to improve the quality of secondary effluent. The secondary effluent from the Dinapur Sewage Treatment Plant Varanasi, India was used in this work. The process of biofiltration with the plant species of Eichornia crassipes and Lemna minor, at a flow rate of 262mlmin -1 and plant density of 30mgL -1 for 48h, in combination with the process of ozonation with ozone dose of 10mgL -1 and contact time of 5min was applied. Results revealed that combined process was statistically most suitable for the highest degradation of physico-chemical and microbial parameters with improving BDOC value. The biofiltration process is able to remove highest percentage of toxic heavy metals from the secondary effluent without production of toxicity. This technique is highly recommendable for tropical wastewater where sewage is mixed with industrial effluents. © 2011 Elsevier Ltd.

Kumari A.,Banaras Hindu University | Kayastha A.M.,Banaras Hindu University
Journal of Molecular Catalysis B: Enzymatic | Year: 2011

α-Amylase from soybeans was immobilized on two different matrices, Chitosan beads and Amberlite MB-150. Maximum immobilization of 62% and 70.4% was obtained with Chitosan and Amberlite MB-150, respectively. The optimum pH obtained was 8.0 and 7.0 for the α-amylase immobilized on Chitosan beads and Amberlite MB-150, respectively; free enzyme showed an optimum pH of 5.5. The optimum temperature for both free and Chitosan immobilized enzymes was 70 °C whereas it was 75 °C for enzyme immobilized on Amberlite MB-150. α-Amylase immobilized on Chitosan showed an apparent K m of 4 mg/mL, whereas Amberlite immobilized enzyme showed an apparent K m of 2.5 mg/mL. The immobilized enzyme showed a high operational stability by retaining 38% and 58% of initial activity after 10 uses for Chitosan and Amberlite, respectively. The easy accessibility of soybean α-amylase, the ease of its immobilization on low-cost matrices, increased stability upon immobilization make it a suitable product for future applications. Both the matrices used for enzyme immobilization are non-toxic, cheap, renewable, biodegradable and have importance in food, cosmetics, biomedical, or pharmaceuticals applications. © 2010 Elsevier B.V.

Kumar D.,Banaras Hindu University | Gaur J.P.,Banaras Hindu University
Bioresource Technology | Year: 2011

The present study explores the suitability of chemical reaction-based and diffusion-based kinetic models for defining the biosorption of Cu(II), Cd(II) and Pb(II) by Phormidium sp.-dominated mat. The time-course data of metal sorption by the test mat significantly (r 2=0.932-0.999) fitted to the chemical reaction-based models namely pseudo-first-order, -second-order, and the general rate law. However, these models fail to accurately describe the kinetics of metal biosorption due either to prefixed order or unjustifiable change in rate constant and reaction order with varying concentrations of metal and biomass in the solution. The diffusion-based models, namely, the intra-particle diffusion model and the external mass transfer model fitted well to the time-course metal sorption data, thus suggesting involvement of both external and intra-particle diffusion processes in sorption of test metals by mat biomass. However, the Boyd kinetic expression clearly showed that the external mass transfer is the dominant process. © 2010 Elsevier Ltd.

Tripathi S.,Banaras Hindu University | Pathak V.,Banaras Hindu University | Tripathi D.M.,Banaras Hindu University | Tripathi B.D.,Banaras Hindu University
Bioresource Technology | Year: 2011

The present work was aimed at studying the efficiency of ozone in oxidation processes, coliform inactivation and Disinfection Byproducts (DBPs) formation, associated with the potential of ozone to increase the Biodegradable Dissolved Organic Carbon (BDOC) in secondary effluent with applied ozone doses of 5.0, 10.0 and 15.0mg/L for contact times of 2, 5 and 10min. The wastewater used in this work was collected from the Bhagwanpur Sewage Treatment Plant, Varanasi, India. Results of this experiment showed that 10mg O 3/L O 3 for 5min exposure was found most suitable dose for highest degradation of COD, TOC, UV 254, color, turbidity and total nitrogen parameters. The inactivation range of microbial biomass range was found in between 95% and 98%. Experiment revealed the fact that aldehydes and carboxylic acid formation were significantly related with the ozone dose and exposure time and ozone might enhance the treatment efficiency of secondary effluent treatment. © 2010 Elsevier Ltd.

Bhadauria B.S.,Banaras Hindu University | Agarwal S.,Banaras Hindu University
Transport in Porous Media | Year: 2011

The present paper deals with linear and nonlinear analysis of thermal instability in a rotating porous layer saturated by a nanofluid. Momentum equation with Brinkman term, involving the Coriolis term and incorporating the effect of Brownian motion along with thermophoresis has been considered. Linear stability analysis is done using normal mode technique, while for nonlinear analysis, a minimal representation of the truncated Fourier series, involving only two terms, has been used. Stationary and oscillatory modes of convection have been studied. A weak nonlinear analysis is used to obtain the concentration and thermal Nusselt numbers. The behavior of the concentration and thermal Nusselt numbers is investigated by solving the finite amplitude equations using a numerical method. Obtained results have been presented graphically and discussed in details. © 2011 Springer Science+Business Media B.V.

Pandey S.K.,Banaras Hindu University | Banik R.M.,Banaras Hindu University
Bioresource Technology | Year: 2011

A study was made to find out maximum partitioning of Bacillus licheniformis alkaline phosphatase in different ATPSs composed of different molecular weight of PEG X (X = 2000, 4000, 6000) with salts (magnesium sulphate, sodium sulphate, sodium citrate) and polymers (dextran 40, dextran T500). Physicochemical factors such as effect of system pH, system temperature and production media were evaluated for partitioning of alkaline phosphatase. PEG 4000 [9.0% (w/v)] and dextran T500 [9.6% (w/v)] were selected as most suitable system components for alkaline phosphatase production by B. licheniformis based on greater partition coefficient (k = 5.23). The two-phase system produced fewer enzymes than the homogeneous fermentation (control) in early stage of fermentation, but after 72. h the enzyme produced in the control system was less than that in the ATPS. Total alkaline phosphatase yield in ATPS fermentation was 3907.01. U/ml and in homogeneous fermentation 2856.50. U/ml. © 2010 Elsevier Ltd.

Kumar D.,Banaras Hindu University | Gaur J.P.,Banaras Hindu University
Bioresource Technology | Year: 2011

The pH-dependent metal sorption by Oscillatoria- and Phormidium-dominated mats was effectively expressed by the Hill function. The estimated Hill functions can fruitfully predict the amount of metal sorbed at a particular initial pH. Pretreatment of biomass with 0.1mmolL -1 HCl was more effective than pretreatment with CaCl 2, HNO 3, NaOH, and SDS in enhancing metal sorption ability of the biomass. Desorption of metal ions in the presence of 100mmolL -1 HCl from metal-loaded mat biomass was completed within 1h. After six cycles of metal sorption/desorption, sorption decreased by 6-15%. Only 6% and 11% of the biomass derived from the Oscillatoria sp.- and Phormidium sp.-dominated mats was lost during the cycling. The cyanobacterial mats seem to have better potential than several biomass types for use in metal sorption from wastewaters as they are ubiquitous, self-immobilized, and have good reusability. © 2010 Elsevier Ltd.

Paramanik V.,Banaras Hindu University | Thakur M.K.,Banaras Hindu University
Cellular and Molecular Neurobiology | Year: 2010

Following binding to cognate ligand, estrogen receptor (ER) β interacts with specific responsive elements of the target genes and recruits a host of nuclear proteins for hormone dependent gene regulation. However, it is poorly known which proteins interact with ER β in mouse brain and whether their interaction and expression change with age. In this report, we have used his-tag mouse ER β for interaction with nuclear proteins of cerebral cortex of young (6 ± 1 weeks), adult (25 ± 2 weeks), and old (70 ± 5 weeks) female mice. We have identified estrogen receptor-associated protein (ERAP) 140 as one of the interacting proteins and studied its interaction by pull down immunoblotting, far-Western blotting and immunoprecipitation, and expression by western blotting. The data show that ERAP 140 interacts with ER β and its interaction decreases but its expression increases with age in mouse cerebral cortex, suggesting its role in estrogen-mediated brain functions during aging. © 2010 Springer Science+Business Media, LLC.

Sharma R.,Banaras Hindu University | Vinayak M.,Banaras Hindu University
Leukemia and Lymphoma | Year: 2012

Overproduction of reactive oxygen species (ROS) due to environmental challenge or metabolic imbalance leads to oxidative stress, causing overactivation of a number of oncogenes that promote cancer development. Therefore, antioxidants should be able to check cancer growth by modulating oncogene activity. The requirement of high energy during unlimited cell proliferation is fulfilled by the switching of cancerous cells to a fast glycolytic pathway bypassing the oxygen dependent respiratory pathway. Almost all cancers exhibit a high expression of lactate dehydrogenase A (LDH-A) to ensure a high energy supply. The present study focused on modulating redox-sensitive oncogenes such as protein kinase C (PKC) and c-Myc by treatment of lymphoma bearing mice with the antioxidant α-tocopherol, the most active component of vitamin E. Further, the impact of α-tocopherol on LDH activity was tested. The results showed down-regulation of expression of stress-activated genes PKC-α, c-Myc and LDH-A by α-tocopherol in cancerous mice. α-Tocopherol contributes to the check of cell proliferation by decreasing the activity of LDH-A. © 2012 Informa UK, Ltd.

Kant S.,Banaras Hindu University | Kumar A.,Banaras Hindu University | Singh S.M.,Banaras Hindu University
Biochimica et Biophysica Acta - General Subjects | Year: 2012

Background: De novo fatty acid synthesis catalyzed by fatty acid synthase (FASN) is crucial for tumor cell survival. Thus therapeutic targeting of FASN is considered as a novel antineoplastic strategy. However, little is understood in this respect regarding malignancies of hematological origin. The present investigation was therefore, undertaken to study the molecular mechanisms of the antitumor action of FASN inhibitor orlistat (tetrahydrolipstatin) using a murine model of a T cell lymphoma. Methods: The antitumor efficacy of orlistat was investigated in vitro by estimating cell survival by MTT assay and apoptosis by Wright Giemsa, TUNEL, Annexin-V/PI staining and % DNA fragmentation. Generation of reactive oxygen species (ROS) in tumor cells was studied using fluorescence microscopy. Expression of genes and proteins was carried out by RT-PCR and western blot analyses respectively. FASN and CPT-1 activity was estimated by spectrophotometer. Cytokines expression was analyzed by ELISA. Results: We report that inhibition of FASN with its specific inhibitor orlistat manifests tumor-specific inhibition of cell survival, accompanied by induction of apoptosis. Orlistat-treated tumor cells showed an altered ROS generation, shift in cytokine balance and modulated expression of cell survival regulatory molecules like HSP70, Bcl2, p53, PUMA, Caspase-3 and CAD. It was observed that IFN-γ mediates orlistat-dependent modulation of FASN expression. Conclusion and general significance: In this study, we report some of the so far unexplored novel aspects underlying the molecular mechanisms associated with orlistat-dependent modulation of tumor cell survival. These observations will help in designing antineoplastic therapeutic protocols using orlistat against malignancies of hematological origin. © 2012 Elsevier B.V.

Sundar S.,Banaras Hindu University | Chakravarty J.,Banaras Hindu University
International Journal of Environmental Research and Public Health | Year: 2010

Antimony toxicity occurs either due to occupational exposure or during therapy. Occupational exposure may cause respiratory irritation, pneumoconiosis, antimony spots on the skin and gastrointestinal symptoms. In addition antimony trioxide is possibly carcinogenic to humans. Improvements in working conditions have remarkably decreased the incidence of antimony toxicity in the workplace. As a therapeutic, antimony has been mostly used for the treatment of leishmaniasis and schistosomiasis. The major toxic side-effects of antimonials as a result of therapy are cardiotoxicity (~9% of patients) and pancreatitis, which is seen commonly in HIV and visceral leishmaniasis co-infections. Quality control of each batch of drugs produced and regular monitoring for toxicity is required when antimonials are used therapeutically. © 2010 by the authors; licensee MDPI, Basel, Switzerland.

Azad U.P.,Banaras Hindu University | Ganesan V.,Banaras Hindu University
Electrochimica Acta | Year: 2011

Polymeric [NiII(teta)]2+ (poly(Ni); teta = C-meso-(5,5,7,12,12,14-hexamethyl-1,4,8,11-tetra-azacyclotetradecane)) modified glassy carbon and Nafion (Nf)-coated glassy carbon electrodes (GC/poly(Ni) and GC/Nf/poly(Ni), respectively) were used for the efficient electrocatalytic oxidation of hydrazine (HZ) in 0.1 M NaOH. The catalytic currents were proportional to the concentration of HZ with a wide linear calibration range (LCR). GC/poly(Ni) had a LCR from 1.0 μM to 10.0 mM, whereas that of GC/Nf/poly(Ni) ranged from 1.0 μM to 100.0 mM. The latter is the widest LCR reported to date. The presence of the Nf film (i.e., in GC/Nf/poly(Ni)) not only increased the stability of the poly(Ni) film but also widened the LCR. The electrocatalytic oxidation of HZ obeyed first-order kinetics with respect to HZ concentration. The kinetic parameters were investigated by cyclic voltammetry and chronoamperometry. © 2011 Elsevier Ltd. All rights reserved.

Kumar P.,Banaras Hindu University | Singh K.,Banaras Hindu University
Journal of Nanoparticle Research | Year: 2011

The projection of integrating optical, magnetic and electronic functionalities into a single material have aggravated passionate attention in mounting wide band gap diluted magnetic semiconductor (DMS) in the midst of room temperature ferromagnetism. We report the evidence of ferromagnetism in Cu-doped ZnSe quantum dots (QDs) below room temperature, grown from a single source precursor by lyothermal method with the sizes of approximately 3.2-5.14 nm. QDs mainly exhibit paramagnetic behavior between 80 and 300 K, with a weak ferromagnetic/anti-ferromagnetic exchange at lower temperature as observed by superconducting quantum interference device (SQUID) magnetometer. From the Curie-Weiss behavior of the susceptibility, Curie temperature (T c) of Cu-doped ZnSe sample has been evaluated. From EPR, we obtain the Lande-g factor in the Zeeman interaction term as 2.060. Photoluminescence and EPR measurements support and confirm the view that Cu2+ substitutes for Zn2+ in Cu-doped ZnSe quantum dots. © 2010 Springer Science+Business Media B.V.

Allam B.K.,Banaras Hindu University | Singh K.N.,Banaras Hindu University
Synthesis | Year: 2011

The present report describes an efficient and simple protocol for phosphine-free Heck reactions in water using a Pd(l-proline)2 complex as the catalyst under controlled microwave irradiation conditions. This methodology is versatile and provides excellent yields of products in short reaction times and minimizes costs, operational hazards and environmental pollution. © Georg Thieme Verlag Stuttgart.

Guntreddi T.,Banaras Hindu University | Vanjari R.,Banaras Hindu University | Singh K.N.,Banaras Hindu University
Tetrahedron | Year: 2014

A new strategy for the synthesis of a variety of dithiocarbamates and thioamides has been developed employing inexpensive and readily available methylarenes under metal-free and solvent-free conditions. The approach offers a one-pot procedure and has also been extended to the synthesis of a diverse range of benzyl esters. © 2014 Elsevier Ltd. All rights reserved.

Tiwari M.P.,Banaras Hindu University | Prasad B.B.,Banaras Hindu University
Journal of Chromatography A | Year: 2014

Molecularly imprinted micro-solid phase extraction fiber was developed by modifying molecularly imprinted polymer film on the surface of silica fiber exploring "grafting via surface attached monomer" (method I) and "grafting via sol-gel" (method II) approaches. The latter approach was found to be inferior to the former one in terms of the sensitivity of insulin detection [method I, LOD=0.009ngmL-1; method II, LOD=0.064ngmL-1, RSD=1.21%]. Notably, either of the techniques, molecularly imprinted micro-solid phase extraction or complementary sensor, was found to be incompetent to monitor the stringent level of insulin in the real samples. However, the combination of these techniques has been found quite suitable for achieving the high detection sensitivity of ultra-trace insulin in human blood serum and Huminsulin injection, without any non-specific (false-positives) contributions. The proposed hyphenated device could serve as a possible marker for risk of developing type 2 diabetes mellitus and diabetic coma due to insulin resistance in human beings. © 2014 Elsevier B.V.

The present study was conducted to investigate if anti-inflammatory drug aspirin could alter the cytotoxic action of cisplatin on tumor cells. Using a transplantable T cell lymphoma in a murine model, we demonstrate that exposure to aspirin exerts a priming action on tumor cells, rendering them susceptible to induction of cell death by cisplatin with consequences on retardation of tumor progression. The priming action of aspirin on tumor cells was found to be dependent on an altered constitution of tumor microenvironment with respect to decline of acidosis and modulation in the expression of cell cycle and survival regulatory molecules like cyclin B1, cyclin D, bcl-2, bcl-xL, p53, and cytokines: IL-4, IL-10, IFN- γ & VEGF. The study also discusses possible mechanisms underlying augmentary action of aspirin on cisplatin-mediated tumor cells killing. This is the first report showing that pre-exposure of tumor cells to aspirin lowers the concentration of cisplatin to exert its cytotoxic action. The finding of this study will help in designing novel antitumor protocols with reduced dose of cisplatin. © 2012 Springer Science+Business Media, LLC.

Pandey S.,Banaras Hindu University | Rai R.,Banaras Hindu University | Rai L.C.,Banaras Hindu University
Journal of Proteomics | Year: 2012

Proteomics in conjunction with morphological, physiological and biochemical variables has been employed for the first time to unravel survival strategies of the diazotrophic cyanobacterium Anabaena sp. PCC7120 under Arsenic (As) stress. Significant reduction in growth, carbon fixation, nitrogenase activity and chlorophyll content after 1. day (1. d) and recovery after 15. days (15. d) of As exposure indicates the acclimation of the test organism against As stress. The formation of akinete like structures is a novel observation never reported before in Anabaena sp. PCC7120. Proteomic characterization using 2-DE showed average 537, 422 and 439 spots in control, 1 and 15. d treatment respectively. MALDI-TOF and LC-MS of As-treated Anabaena revealed a total of 45 differentially expressed proteins, of which 13 were novel (hypothetical) ones. Down-regulation of phosphoglycerate kinase (PGK), fructose bisphosphate aldolase II (FBA II), fructose 1,6 bisphosphatase (FBPase), transketolase (TK), and ATP synthase on day 1 and their significant recovery on the 15th day presumably maintained the glycolysis, pentose phosphate pathway (PPP) and turnover rate of Calvin cycle, hence survival of the test organism. Up-regulation of catalase (CAT), peroxiredoxin (Prx), thioredoxin (Trx) and oxidoreductase appears to protect the cells from oxidative stress. Appreciable induction in phytochelatin content (2.4 fold), GST activity (2.3 fold), and transcripts of phytochelatin synthase (5.0 fold), arsenate reductase (8.5 fold) and arsenite efflux genes - asr1102 (5.0 fold), alr1097 (4.7 fold) reiterates their role in As sequestration and shielding of the organism from As toxicity. While up-regulated metabolic and antioxidative defense proteins, phytochelatin and GST work synchronously, the ars genes play a central role in detoxification and survival of Anabaena under As stress. The proposed hypothetical model explains the interaction of metabolic proteins associated with the survival of Anabaena sp. PCC7120 under As stress. © 2011 Elsevier B.V.

Prasad V.,Banaras Hindu University | Kale R.R.,Banaras Hindu University | Mishra B.B.,Banaras Hindu University | Kumar D.,Banaras Hindu University | Tiwari V.K.,Banaras Hindu University
Organic Letters | Year: 2012

A novel, one-pot, and highly facile protocol has been devised for an easy access of a series of novel glycosyl carboxamides from aldehydes using diacetoxyiodobenzene in the presence of ionic liquid at ambient temperature. © 2012 American Chemical Society.

Upadhyay K.K.,Banaras Hindu University | Kumar A.,Banaras Hindu University
Organic and Biomolecular Chemistry | Year: 2010

A new fluorescent probe (5-[(4-diethylamino-2-hydroxy-benzylidene)-amino]- 1H-pyrimidine-2, 4-dione) (Receptor1) has been synthesized by the Schiff base condensation of 5-aminouracil with 4-(diethylamino)salicylaldehyde. The receptor 1 exhibits high selectively for Al3+ in DMSO as well as in aqueous solution even in the presence of biologically relevant cations such as Na +, K+, Ca2+, Mg2+, Pb2+ and several transition metal ions. The lowest detection limit for the receptor 1 was found to be 1.62 × 10-10 M with its linear response towards Al3+ in the concentration range of 1.75 × 10 -9 to 3.3 × 10-8 M in DMSO. Receptor 1 is the first ever example where a single molecular probe is able to show imine (CN) isomerization inhibition along with twisted intramolecular charge transfer (TICT) in combinatorial fashion. © 2010 The Royal Society of Chemistry.

Singh M.S.,Banaras Hindu University | Nandi G.C.,Banaras Hindu University | Samai S.,Banaras Hindu University
Green Chemistry | Year: 2012

An efficient and convergent route to 3-aroyl-4-aryl-2-arylamino-4,6,7,8- tetrahydrochromen-5-ones and hitherto unreported 3-aroyl-4-aryl-2-arylamino-4H- pyrano[3,2-c]chromen-5-ones has been developed by an one-pot three-component domino coupling of α-oxoketene-N,S-arylaminoacetals, aromatic aldehydes, and dimedone/4-hydroxycoumarin in the presence of DABCO under solvent-free conditions in high yields. Further, suitably substituted pyrano[3,2-c]chromen-5- ones undergo intramolecular aromatic nucleophilic substitution (S NAr) to give pentacyclic pyrano[3,2-c]chromenoquinolines in excellent yields. The merit of this cascade Knoevenagel condensation/Michael addition/cyclization sequence is highlighted by its high atom-economy, good yields, efficiency of producing three new bonds (two C-C and one C-O), and one stereocenter in a single operation. The protocol avoids the use of expensive catalysts, toxic organic reagents/solvents, and anhydrous condition. In particular the attractive feature of this approach is the synthesis of three important bioactive heterocyclic frameworks from the same α-oxoketene-N,S-arylaminoacetal under the similar reaction conditions making this new strategy highly useful in diversity oriented synthesis (DOS). © 2012 The Royal Society of Chemistry.

Pandey P.C.,Banaras Hindu University | Chauhan D.S.,Banaras Hindu University
Analyst | Year: 2012

The in situ synthesis is reported of noble metal nanoparticles via 3-glycidoxypropyltrimethoxysilane mediated reduction of 3- aminopropyltrimethoxysilane treated metal salts during sol-gel processing. The method described involves the synthesis of uniform spherical nanoparticles of gold, silver and palladium with controlled size that can be directly utilized for thin film preparation. A detailed study of the synthesis and application of gold nanoparticles to the electrochemical detection of hydrogen peroxide was carried out and reveals that the amplification of hydrogen peroxide sensing is size-dependent. In addition, these nanoparticles exhibit excellent compatibility towards composite preparation. As an example, a nanocomposite with Prussian Blue (PB) is synthesized and found to be useful for the fabrication of chemically modified electrodes (CME). The resulting CME shows dramatic improvement in the electrochemistry of PB with gradual enhancement in electrocatalytic efficiency towards hydrogen peroxide sensing. The nanocomposite is used to study the direct and horseradish peroxidase (HRP)-catalyzed reduction of hydrogen peroxide. The results recorded for hydrogen peroxide analysis show an improvement in sensitivity and limit of detection on decreasing the size of gold nanoparticles in all cases. © 2012 The Royal Society of Chemistry.

Haldar C.,Banaras Hindu University | Ahmad R.,Banaras Hindu University
Journal of Photochemistry and Photobiology B: Biology | Year: 2010

The seasons, and daily physical rhythms can have a profound effect on the physiology of the living organism, which includes immune status. The immune system can be influenced by a variety of signals and one of them is photic stimulus. Light may regulate the immunity through the neuroendocrine system leading to the most recent branch of research the "Photoimmunomodulation". Mammals perceive visible light (400-700 nm) through some specialized photoreceptors located in retina like retinal ganglion cells (RGC). This photic signal is then delivered to the visual cortex from there to the suprachiasmatic nucleus (SCN) of the hypothalamic region. Melatonin - one of the universally accepted chronobiotic molecule secreted by the pineal gland is now emerging as one of the most effective immunostimulatory compound in rodents and as oncostatic molecule at least in human. Its synthesis decreases with light activation along with norepinephrine and acetylcholine. The changes in level of melatonin may lead to alterations (stimulatory/inhibitory) in immune system. The evidences for the presence of melatonin receptor subtypes on lymphoid tissues heralded the research area about mechanism of action for melatonin. Further, melatonin receptor subtypes-MT1 and MT2 was noted on pars tuberalis, SCN and on lymphatic tissues suggesting a direct action of melatonin in modulation of immunity by photoperiod as well. The nuclear receptors (ROR, RZR etc.) of melatonin are known for its free radical scavenging actions and might be indirectly controlling the immune function. © 2009.

Kushwaha D.,Banaras Hindu University | Singh R.S.,Banaras Hindu University | Tiwari V.K.,Banaras Hindu University
Tetrahedron Letters | Year: 2014

Carbohydrate based fluorescent sensors S1 and S2 have been developed by fluorogenic dual click chemistry and are characterized by various spectroscopic techniques. Both the fluorescent probes displayed highly selective detection of Cu2+ ions by means of fluorescence quenching. The job plot experiment suggested 1:1 complexation of probes S1 and S2 with Cu2+ ions having detection limit of 6.99 μM and 7.30 μM, respectively. The binding constants for S1-Cu2+ and S2-Cu2+ complexation were evaluated to be 3.34 × 103 M-1 and 5.93 × 103 M-1, respectively. © 2014 Elsevier Ltd. All rights reserved.

Prasad B.B.,Banaras Hindu University | Jauhari D.,Banaras Hindu University | Tiwari M.P.,Banaras Hindu University
Biosensors and Bioelectronics | Year: 2014

A rapid, selective, and sensitive double-template imprinted polymer nanofilm-modified pencil graphite electrode was fabricated for the simultaneous analysis of phosphorus-containing amino acid-type herbicides (glyphosate and glufosinate) in soil and human serum samples. Since both herbicides respond overlapped oxidation peaks and only glyphosate is prone to nitrosation, n-nitroso glyphosate and glufosinate were used as templates for obtaining the well-resolved quantitative differential pulse anodic stripping voltammetric peaks on the proposed sensor. Toward sensor fabrication, a nano-structured polymer film was first grown directly on the electrode via initial immobilization of gold nanoparticles at its surface. This was followed by linking of monomeric (N-methacryloyl-l-cysteine) molecules through S-Au bonds. Subsequently, these molecules were subjected to free radical polymerization, in the presence of templates, cross linker, initiator, and multiwalled carbon nanotubes as pre-polymer mixture. The modified sensor observed wide linear ranges (3.98-176.23ngmL-1 and 0.54-3.96ngmL-1) of simultaneous analysis with detection limits as low as 0.35 and 0.19ngmL-1 (S/N=3) for glyphosate and glufosinate, respectively, in aqueous samples. The respective oxidation peak potentials of both analytes were found to be substantially apart by 265mV. This enabled the simultaneous determination of one target in the presence of other, without any cross reactivity, interferences, and false-positives, in real samples. © 2014 Elsevier B.V.

Prasad B.B.,Banaras Hindu University | Tiwari M.P.,Banaras Hindu University | Madhuri R.,Banaras Hindu University | Sharma P.S.,Banaras Hindu University
Journal of Chromatography A | Year: 2010

Thyroxine is a known disease biomarker which demands a highly sensitive and selective technique to measure ultratrace level with enantiodifferentiation of its optical isomers (d- and l-), in real samples. In this work, an approach of hyphenation between molecularly imprinted micro-solid phase extraction and a complementary molecularly imprinted polymer-sensor was adopted for enantioseparation, preconcentration, and analysis of d- and l-thyroxine. In both techniques, the same imprinted polymer, coated on a vinyl functionalized self-assembled monolayer modified silver wire, was used as the respective extraction fiber as well as sensor material. This combination enabled enhanced preconcentration of test analyte substantially so as to achieve the stringent limit [limit of detection: 0.0084ngmL-1, RSD=0.81%, S/N=3 (d-thyroxine); 0.0087ngmL-1, RSD=0.63%, S/N=3 (l-thyroxine)] of clinical detection of thyroid-related diseases, without any problems of non-specific false-positive contribution and cross-reactivity. © 2010 Elsevier B.V.

Ahmad R.,Banaras Hindu University | Gupta S.,Banaras Hindu University | Haldar C.,Banaras Hindu University
Free Radical Research | Year: 2012

Age-dependent declining level of melatonin induces free radical load and thereby deteriorates immune function. However, reports are lacking about age-dependent melatonin membrane receptor (MT1 & MT2) expression, their role in regulation of reactive nitrogen species (RNS) and eventually how they affect immunity of a tropical rodent F. pennanti. We checked MT1R, MT2R and iNOS expression in lymphoid organs of young middle and old aged squirrels. Nitrite and nitrate ion concentration (NOx) in lymphoid organs, testes and plasma, lymphocyte proliferation and IL-2 level was recorded. Age-dependent decrease in MT1 and MT2 receptor expression, lymphocyte proliferation, IL-2 level and increased RNS in lymphoid organs, testes and plasma was observed with decreased circulatory melatonin. Androgen and AR expression was increased in middle-aged while declined in old-aged squirrels. Present study suggests that age associated immunosenescence is consequence of increased RNS which might have important relationship with melatonin membrane receptors in F. pennanti. © 2012 Informa UK, Ltd.

Kumar A.,Banaras Hindu University | Bhadauria B.S.,Banaras Hindu University
Transport in Porous Media | Year: 2011

Double diffusive convection in a rotating anisotropic porous layer, saturated by a viscoelastic fluid, heated from below and cooled from above has been studied making linear and non-linear stability analyses. The fluid and solid phases are considered to be in equilibrium. In momentum equation, we have employed the Darcy equation which includes both time derivative and Coriolis terms. The linear theory based on normal mode method is considered to find the criteria for the onset of stationary and oscillatory convection. A weak non-linear analysis based on minimal representation of truncated Fourier series analysis containing only two terms has been used to find the Nusselt number and Sherwood number as functions of time. We have solved the finite amplitude equations using a numerical scheme. The results obtained, during the above analyses, have been presented graphically and the effects of various parameters on heat and mass transfer have been discussed. Finally, we have drawn the steady and unsteady streamlines, isotherms, and isohalines for various parameters. © 2010 Springer Science+Business Media B.V.

Das L.,Banaras Hindu University | Vinayak M.,Banaras Hindu University
Bioscience Reports | Year: 2012

NF-κB (nuclear factor κB) plays a significant role in inflammation, immunity, cell proliferation, apoptosis and malignancy. ROS (reactive oxygen species) are among the most important regulating factors of NF-κB. Intracellular ROS are mainly regulated by an endogenous antioxidant defence system. Any disruption of redox balance leads to oxidative stress, which causes a number of pathological conditions including inflammation and malignancy. Increased metabolic activity in cancerous cells leads to oxidative stress, which is further enhanced due to depletion of the endogenous antioxidant defence system. However, the activation and signalling of NF-κB are reported to be inhibited by overexpression and induced activity of antioxidant enzymes. Therefore the present study focuses on the correlation between the endogenous antioxidant defence system, ROS and NF-κB activation during lymphoma growth in mice. The study highlights the anti-carcinogenic role of curcumin by modulation of NF-κB activation and oxidative stress via the endogenous antioxidant defence system. Oxidative stress was monitored by lipid peroxidation, protein carbonylation and antioxidant enzyme activity. NF-κB-mediated signalling was tested by DNA-binding activity. The results reflect that intracellular production of H 2O 2 in oxidative tumour micro-environment regulates NF-κB activation. Curcumin inhibits oxidative state in the liver of lymphoma-bearing mice by enhancing the transcription and activities of antioxidant enzymes, which in turn modulate activation of NF-κB, leading to a decrease in lymphoma growth. Morphological changes as well as cell proliferation and cell survival assays confirmed reduced lymphoma growth. Thus curcumin contributes to cancer prevention by disrupting the vicious cycle of constant ROS production, responsible for a high oxidative micro-environment for tumour growth. ©The Authors Journal compilation ©2012 Biochemical Society.

Singh A.,Banaras Hindu University | Krishna A.,Banaras Hindu University
General and Comparative Endocrinology | Year: 2012

The aim of this study was to evaluate the seasonal variation in serum adiponectin levels and ovarian expression of adiponectin and its receptor in the Scotophilus heathi bat and their relationship to the changes in the body fat mass, serum insulin and luteinizing hormone (LH) levels, and ovarian activity. A very high level of circulating adiponectin was found during recrudescence, whereas a very low level of circulating adiponectin was observed during pre-ovulatory period. The increased circulating adiponectin level coincided with fat deposition, insulin resistance and hyperinsulinemia (HI) in S. heathi. Immunocytochemical study in the ovary of bat showed localization of adiponectin mainly in thecal-interstitial cells (TICs), and adiponectin receptor 1 (AdipoR1) in the granulosa cells of growing follicles, but showed no staining in atretic follicle. Seasonal changes in ovarian adiponectin and AdipoR1 levels showed two peaks (during recrudescence and ovulatory phases) coinciding with two periods of follicular development. Adiponectin in the absence of LH, as occur during recrudescence, stimulates androstenedione (A4) synthesis in vitro by up-regulating the insulin receptor (IR). Adiponectin in presence of LH, as occur during pre-ovulatory phase, inhibits A4 synthesis in vitro by down-regulating androgen receptor (AR). Further, the in vitro study showed that adiponectin, in presence of LH, also promotes luteinizing hormone receptor (LH-R) and steroidogenic acute regulatory protein (StAR) level in the ovary, which might help in development of ovulatory follicles. In brief, adiponectin in the absence of LH induces increased A4 synthesis and consequently the condition of delayed ovulation, whereas in the presence LH suppresses both synthesis and action of A4 and thus induces preovulatory condition in the ovary of S. heathi. © 2012 Elsevier Inc.

Mishra A.K.,Banaras Hindu University | Rai R.,Banaras Hindu University | Agrawal S.B.,Banaras Hindu University
Field Crops Research | Year: 2013

In past few years, atmospheric concentrations of carbon dioxide (CO2) and tropospheric ozone (O3) have increased due to anthropogenic activities. CO2 enhances the plant growth and surface level of O3 is a well-known phyto-toxic pollutant. Present study was conducted to assess the impact of elevated levels of CO2 and O3, singly and in combination on two wheat cultivars HUW-37 and K-9107 on their growth, yield attributes and grain quality in open top chambers (OTCs). Wheat plants under elevated CO2 (EC) showed increment in growth parameters while exposure to elevated O3 (EO) showed an opposite trend than EC. In elevated CO2+O3 (ECO) exposure, elevated CO2 fully protected wheat cultivars against negative effects of O3. Yield parameters showed significant increase in EC followed by ECO and in EO, significant reductions in yield were noticed in both the cultivars. Protein and total free amino-acids decreased in grains of EC, ECO and EO in both the test cultivars. Total soluble sugars and starch contents in grains increased due to EC and ECO and decreased in EO, however reducing sugars showed an opposite trend in both the cultivars. The yield data obtained from the experiment showed cultivar specific response as cultivar HUW-37 proved to be sensitive as compared to K-9107 against ambient and elevated levels of O3. The study also concludes that elevated CO2 nullified the negative impact of elevated O3 in both the test cultivars of wheat. © 2013 Elsevier B.V.

Pandey P.C.,Banaras Hindu University | Pandey A.K.,Banaras Hindu University
Analyst | Year: 2012

A nanocomposite of nickel hexacyanoferrate (NiHCF) was made with gold nanoparticles (AuNPs) of two different sizes (20 and 80 nm as AuNP red and AuNP blue respectively), synthesized via 3- glycidoxypropyltrimethoxysilane mediated reduction of 3- aminopropyltrimethoxysilane treated gold chloride and characterized by scanning electron microscopy and UV-VIS spectroscopy. The size of AuNPs was found to influence the two pairs of reversible voltammetric peaks of cation rich and cation deficient NiHCF. Such influence was identified from cyclic voltammetry of nanocomposite modified electrodes and applications during electrochemical sensing of two different analytes hydrazine and glutathione (GSH). Electrochemical sensing of hydrazine was based on cyclic voltammetry and differential pulse voltammetry (DPV) found as a function of sodium deficient NiHCF and was greatly amplified with increasing AuNPs nanogeometry. NiHCF alone is not an efficient electrode material for GSH analysis at the level required, however, the presence of AuNPs introduces size dependent sensitive and selective detection of GSH. GSH sensing based on linear sweep voltammetry (LSV) was found to be mediated by the potassium rich form of NiHCF redox couple in the presence of AuNPs. The results justified electrochemical detection of these analytes based on a mediated mechanism and support the role of AuNPs for facilitated electrochemical activity of NiHCF based systems as a function of nanogeometry. © 2012 The Royal Society of Chemistry.

Kumar V.,Banaras Hindu University | Kumar A.,Banaras Hindu University | Diwan U.,Banaras Hindu University | Upadhyay K.K.,Banaras Hindu University
Dalton Transactions | Year: 2013

A coumarin-based Schiff base (receptor 1) exhibited fluorescence enhancement selectively with Zn2+ at a nanomolar level in near-aqueous medium (EtOH-H2O; 1:1, v/v). The response was instantaneous with a detection limit of 3.26 × 10-9 M. The sensing event is supposed to incorporate a combinational effect of intramolecular charge transfer (ICT), chelation-enhanced fluorescence (CHEF) and CN isomerization mechanisms. Various spectroscopic methods, viz. IR, UV-visible, fluorescence and NMR in association with single crystal XRD studies, were used for thorough investigation of the structure of receptor 1 as well as of the sensing event. The Zn2+ complex of receptor 1 exhibited a very nice 1D chain coordination polymeric framework in its single crystal XRD. This journal is © 2013 The Royal Society of Chemistry.

Madhu,Banaras Hindu University | Singh R.N.,Banaras Hindu University
International Journal of Hydrogen Energy | Year: 2011

Palladium selenides, PdSe, Pd3Se and PdSe2 have been prepared by the hydrothermal method and investigated for their structural and electrocatalytic properties toward the oxygen reduction reaction (ORR) using SEM/TEM, XRD, cyclic and linear sweep voltammetries. The crystallites of PdSe and PdSe2 are found to follow tetragonal and orthorhombic crystal structures, respectively. The PdSe electrode in 0.5 M H2SO 4 exhibits significantly higher electrocatalytic activity than the Pd3Se or PdSe2 electrode under similar experimental conditions. Further, a change in the palladium/selenium ratio from unity in the catalyst results in low ORR activity. © 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

Kushwaha S.,Banaras Hindu University | Bahadur L.,Banaras Hindu University
International Journal of Hydrogen Energy | Year: 2011

We report the photoelectrochemical characteristics of some biologically used dye: Bromophenol, Ponceau S, Sudan IV, Giemsa, and Acridine Orange as sensitizers. The JSC from 2.5 to 0.47 mA cm-2 with the order Bromophenol > Ponceau S > Sudan IV > Giemsa > Acridine orange, the VOC from 642 to 384 mV, the fill factor (FF) from 0.61 to 0.40, and Pmax from 855 to 84 μW cm-2 were obtained from the DSSCs sensitized with these metal free organic dyes. Among these dyes, Bromophenol gave the best performance as sensitizer with maximum current, which is due to the better interaction between the hydroxyl groups of the dye on the surface of ZnO porous film. Incident photon- to-current conversion efficiency (IPCE) achieved with the use of these dyes follows the order Ponceau S > Sudan IV > Bromophenol > Giemsa > Acridine orange. © 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

Singh A.K.,Banaras Hindu University | Quraishi M.A.,Banaras Hindu University
Corrosion Science | Year: 2011

The corrosion inhibition properties of disulfiram (DSR) for mild steel in HCl solution were analyzed by electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, atomic force microscopy, scanning electron microscopy and gravimetric methods. Physical adsorption is proposed for the inhibition and the process followed the Langmuir adsorption isotherm and kinetic/thermodynamic model of El-Awady et al. Constant phase elements describing the non-ideal characteristics of the electrochemical interface are introduced. The occurrence of inductive loop is also dealt with, through the introduction of an inductive element L. The use of these elements significantly improved the quality of fit of simulation to the EIS data. © 2011 Elsevier Ltd.

Singh R.,Banaras Hindu University | Allam B.K.,Banaras Hindu University | Raghuvanshi D.S.,Banaras Hindu University | Singh K.N.,Banaras Hindu University
Tetrahedron | Year: 2013

A new synthetic strategy is developed for the construction of C-N bond through the assistance of Brønsted acid/[DBU][HOAc] without adding any metal catalyst. This is the first efficient SNAr methodology utilizing fluoro, chloro, bromo, and iodoarenes as coupling partners, which offers excellent yield up to 94% within a very short time. © 2012 Elsevier Ltd. All rights reserved.

Kumari K.,Banaras Hindu University | Raghuvanshi D.S.,Banaras Hindu University | Singh K.N.,Banaras Hindu University
Tetrahedron | Year: 2013

2H-Chromen-3-yl-methylenemalononitriles/cyanoacrylates/cyanoacrylamides with variant structural features have been serendipitously formed during an endeavour to prepare 5H-chromeno[3,4-c]pyridine using CuI/(NH4) 2HPO4 catalyzed reaction of O-propargyl salicylaldehyde with malononitrile/ethyl cyanoacetate/cyanoacrylamide. The process is convenient, speedy and high yielding, and the products formed have been finally characterized by X-ray diffraction analysis. © 2012 Elsevier Ltd. All rights reserved.

Balsora H.K.,Banaras Hindu University | Mondal M.K.,Banaras Hindu University
Journal of Chemical and Engineering Data | Year: 2011

This work presents experimental results on the solubility of CO 2 in a new blend of diethanolamine (DEA) and trisodium phosphate (TSP) at temperatures ranging from (303.14 to 333.14) K and partial pressures from (10.133 to 20.265) kPa. Total concentrations of aqueous DEA + TSP blends were taken as (1.0, 1.5, and 2.0) mol·dm -3. In a particular blend, the mole fraction of TSP was in the range 0.02 to 0.20. The results show that CO 2 solubility in a blend with a particular total concentration increases with increasing mole fraction of TSP at fixed temperature and partial pressure of CO 2. The solubility of CO 2 in the blend decreases with increasing temperature but increases with increasing CO 2 partial pressure. The maximum CO 2 solubility in DEA + TSP blends was found to be 0.869 (mol of CO 2)·(mol of absorbent) -1 at 313.14 K, a total concentration of 2.0 mol·dm -3, and a TSP mole fraction of 0.2. The experimental results of the present study are compared with those for other blends available in the literature. © 2011 American Chemical Society.

Vanjari R.,Banaras Hindu University | Allam B.K.,Banaras Hindu University | Singh K.N.,Banaras Hindu University
Tetrahedron Letters | Year: 2013

An easy acylation and formylation of amines has been achieved via transamidation using 1,4-dioxane. The investigation works efficiently without an added catalyst and completes within short time under microwave irradiation. © 2013 Elsevier Ltd. All rights reserved.

Upadhyay S.,Banaras Hindu University
Bulletin of Materials Science | Year: 2013

Polycrystalline powder of BaSnO3 was prepared at 1300 °C using a high-temperature solid-state reaction technique. X-ray diffraction analysis indicated the formation of a single-phase cubic structure with lattice parameter: a = (4.1158 ± 0.0003) Å. The synthesized powder was characterized using X-ray diffraction (XRD) scanning electron micrographs, energy dispersive X-ray analysis, differential thermal analysis, thermogravimetric analysis and Fourier transform infrared techniques. Electrical properties were studied using a.c. impedance spectroscopy technique in the temperature range of 50-650 °C and frequency range of 10 Hz-13 MHz. The complex impedance plots at temperature ≥300 °C show that total impedance is due to the contributions of grains, grain boundaries and electrode. Resistance of these contributions has been determined. Variation of these resistances with temperature shows the presence of two different regions with different slopes. The nature of variation for the above three resistances, in both the temperature regions confirms that conducting species (phases) responsible for grain, grain boundaries and electrode are the same. Based on the value of activation energy, it is proposed that conduction via hopping of doubly ionized oxygen vacancies (V••o) is taking place in the temperature region of 300-450 °C, whereas in the temperature region of 450-650 °C, hopping of proton, i.e. OH• ions occurs. © 2013 Indian Academy of Sciences.

Mohanty A.,Banaras Hindu University | Srivastava V.K.,Banaras Hindu University
Materials and Design | Year: 2013

Epoxy/alumina nanocomposites were prepared by reducing micron size alumina into nanosize during the casting process. In our current investigation it was found that, at low concentration alumina nanoparticles exhibit uniform dispersion of alumina nanoparticles in epoxy nanocomposite while at higher concentration they depict aggregation of alumina particle. Since uniform dispersion of alumina nanoparticles results in improved thermal stability and viscoelastic behavior. It leads to remarkable improvement in breakdown voltage, and breakdown time of epoxy/alumina nanocomposites as compared to neat epoxy. Epoxy nanocomposites containing 2. wt.% of alumina particles results in increase of breakdown voltage by 91% and breakdown time by 155% as compared to neat epoxy. Hence, the nanocomposites developed can be used as insulating material in electrical instruments which require high breakdown voltage as well as improved viscoelastic behavior and thermal stability. © 2012 Elsevier Ltd.

Singh L.,Banaras Hindu University | Rai U.S.,Banaras Hindu University | Mandal K.D.,Banaras Hindu University
Journal of Alloys and Compounds | Year: 2013

Effect of doping of Mg2+ at Cu2+ site has been examined in CaCu3Ti4O12. CaCu 2.70Mg.30Ti4O12 was synthesized by semi- wet chemical method, for the first time, using solid TiO2 and metal nitrate solutions. XRD analysis confirmed the formation of single-phase material, and the structure does not change on doping of Mg and it remains cubic similar to CaCu3Ti4O12 (CCTO). The average particle size in sintered powder of the ceramic obtained from XRD and Transmission electron microscopy (TEM) was found 59 ± 05 and 90 ± 25 nm, respectively. SEM image shows the presence of bimodal grains while EDX analysis confirmed copper oxide rich phase a grain boundary. We found exceptionally very high dielectric constant 86,084 at 500 K on partially substituted Mg2+ at Cu-site in CCTO ceramic at 1 kHz. The nature of relaxation behavior of the ceramic was also rationalized by impedance and modulus spectroscopic analysis. Modulus spectroscopic studies confirmed the Maxwell-Wagner relaxation arising due to the interfaces between grain and grain boundary. © 2012 Elsevier B.V. All rights reserved.

Mishra S.,Banaras Hindu University
European Journal of Clinical Microbiology and Infectious Diseases | Year: 2013

Helicobacter pylori remains a controversial organism with regards to humans, with its epidemiology still being unclear nearly two decades after its discovery. The association between H. pylori infection and subsequent development of chronic active gastritis, peptic ulcer disease, gastric cell carcinoma, and B cell mucosa-associated lymphoid tissue (MALT) lymphoma has been well established. Current studies, however, suggest that fewer than 20 % of all infected patients will develop any consequences from their infection. Hence, should the infection be considered a disease not at all or, on the contrary, is the microorganism harmful in only some circumstances? This article attempts to weigh the currently available evidence supporting that H. pylori may be good and not always bad. © 2012 Springer-Verlag Berlin Heidelberg.

Raghubanshi H.,Banaras Hindu University | Hudson M.S.L.,Banaras Hindu University | Srivastava O.N.,Banaras Hindu University
International Journal of Hydrogen Energy | Year: 2011

In this communication, we report the synthesis of helical carbon nanofibres (HCNFs) by employing hydrogen storage intermetallic LaNi5 as the catalyst precursor. It was observed that oxidative dissociation of LaNi 5 alloy (2LaNi5 + 3/2O2 → La 2O3 + 10Ni) occurred during synthesis. The Ni particles obtained through this process instantly interacted with C2H 2 and H2 gases, and fragmented to nanoparticles of Ni (∼150 nm) with polygonal shape. These polygonal shapes of Ni nanoparticles were decisive for the growth of helical carbon nanofibres (HCNFs) at 650 °C. TEM, SAED and EDAX studies have shown that HCNFs have grown on Ni nanoparticles. Typical diameter and length of the HCNFs are ∼150 nm and 6-8 μm respectively. BET surface area of these typical HCNFs has been found to be 127 m2/g. It was found that at temperature 750 °C, spherical shapes of Ni nanoparticles were produced and decisive for the growth of planar carbon nanofibres (PCNFs). The diameter and length of the PCNFs are ∼200 nm and 6-8 μm respectively. In order to explore the application potential of the present as-synthesized CNFs, they were used as a catalyst for enhancing the hydrogen desorption kinetics of sodium aluminum hydride (NaAlH4). We have found that the present as-synthesized HCNFs, with metallic impurities, indeed work as an effective catalyst. The pristine NaAlH4 and 8 mol% as-synthesized HCNFs admixed NaAlH4, at 160 °C-180 °C and for the duration of 5 h, liberate 0.8 wt% and 4.36 wt% of hydrogen, respectively. Thus there is an enhancement of ∼5 times in kinetics when as-synthesized HCNFs are used as the catalyst. To the best of our knowledge, the use of hydrogen storage alloy LaNi5 as the catalyst precursor for the growth of HCNFs has not yet been done and thus represents a new feature relating to the growth of HCNFs. Furthermore, we have shown that the as-synthesized HCNFs work as an effective new catalyst for improving the dehydrogenation kinetics of the complex hydride, NaAlH4. © 2010, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

Singh D.K.,Banaras Hindu University | Singh V.B.,Banaras Hindu University
Journal of the Electrochemical Society | Year: 2011

Electrodeposited Ni-SiC composite deposits with 10.5 wt % SiC were produced on copper substrate using a non-aqueous organic solvent. N-Methylformamide was found to be the most suitable solvent as it has a high dielectric constant (182) that allows high tolerance of the electrolyte in the bath, which is ordinarily not obtained in other solvents. The optimum condition arrived for deposition was nickel acetate 200 g/l, boric acid 35 g/l, SiC 10 g/l, current density 2.0 A dm-2, duration of electrolysis 30 min, and bath temperature 60°C. Satisfactory bright composite deposits were obtained, which were quite adherent to the copper base. Scanning electron microscope, energy-dispersive analysis by x ray, and X-ray diffraction studies have been performed to characterize the composites. Effect of current density on composition and microhardness of the composite deposits was investigated. Also, the effect of annealing on the microhardness of the deposits was studied. © 2010 The Electrochemical Society.

Upadhyay K.K.,Banaras Hindu University | Kumar A.,Banaras Hindu University
Talanta | Year: 2010

An interference-free naked-eye recognition of Al3+ at its micromolar level has been done in 5% aqueous DMSO solution employing a Schiff base 5-[(2-hydroxy-5-nitro-benzylidene)-amino]-1H-pyrimidine-2,4-dione (receptor 1) which is an intramolecular charge transfer (ICT) probe. The pyrimidine and nitrophenyl groups serve as electron rich (donor) and deficient (acceptor) pockets in receptor 1 exhibiting a broad ICT band at 434 nm (olive green). The concomitant additions of Al3+ as its chloride salt to the 5 × 10-5 M aqueous DMSO solution of the receptor 1 lead hypsochromic shifting of its ICT band to 395 nm (colorless). The same ICT band undergoes a marginal bathochromic shifting (6 nm) along with a hyperchromic shift on separate additions of a basic anion like F-, CH3COO - and H2PO4 - to the receptor 1 and faced almost similar fate on concomitant additions of Al3+ as mentioned above. © 2010 Elsevier B.V. All rights reserved.

Singh A.K.,Banaras Hindu University | Lakhotia S.C.,Banaras Hindu University
Journal of Biosciences | Year: 2012

Hrp36/Hrb87F is one of the most abundant and well-characterized hnRNP A homolog in Drosophila and is shown to have roles in regulation of alternative splicing, heterochromatin formation, neurodegeneration, etc. Yet, hrp36 null individuals were reported to be viable and without any apparent phenotype, presumably because of overlapping functions provided by Hrp38 and related proteins. Here we show that loss of both copies of hrp36 gene slows down development with significant reduction in adult life span, decreased female fecundity and high sensitivity to starvation and thermal stresses. In the absence of Hrp36, the nucleoplasmic omega speckles are nearly completely disrupted. The levels of nuclear matrix protein Megator and the chromatin remodeller ISWI are significantly elevated in principal cells of larval Malpighian tubules, which also display additional endoreplication cycles and good polytene chromosomes. We suggest that besides the non-coding hsrΩ-n transcripts, the Hrp36 protein is also a core constituent of omega speckles. The heat-shock-induced association of other hnRNPs at the hsrΩ locus is affected in hrp36 null cells, which may be one of the reasons for their high sensitivity to cell stress. Therefore, in spite of the functional redundancy provided by Hrp38, Hrp36 is essential for normal development and for survival under conditions of stress. © Indian Academy of Sciences.

Sisodia S.,Banaras Hindu University | Singh B.N.,Banaras Hindu University
Journal of Thermal Biology | Year: 2010

Exposure of various Drosophila species to mild increase or decrease in temperature has consistently been shown to result in increased resistance to subsequent temperature extremes. We investigated cold tolerance in 45 Indian natural populations of Drosophila ananassae collected from all over India by monitoring the time taken by adults to recover from chill-coma after a treatment for 16 h at 4 °C. Significant latitudinal and altitudinal differentiation was observed for chill coma recovery in D. ananassae. Chill-coma recovery was closely associated with local climatic factors like average annual temperature and relative humidity of origin of populations. Role of growth temperature on chill-coma recovery was also analyzed. In all cases, recovery time decreased when growth temperature was lowered and linear reaction norms were observed. Populations from higher latitudes were more cold resistance than low latitude populations. Our results also suggest that within species cold adaptation and response may vary with latitude as a consequence of direct or indirect effects of selection. Our study extends evidence for a higher cold tolerance in north Indian populations that seems to have evolved during the colonization of D. ananassae and supports the hypothesis of an adaptive response of plasticity to the experienced environment. © 2010 Elsevier Ltd. All rights reserved.

Chaturvedi R.K.,Banaras Hindu University | Raghubanshi A.S.,Banaras Hindu University
Forest Ecology and Management | Year: 2015

We investigated vegetation characteristics, carbon density (CD) and carbon accumulation (CA) of trees in mono- and multi-specific, Tectona grandis (Teak) and Shorea robusta (Sal) forest stands in a tropical dry region of India to address the following questions: (i) How are the mono- and multi-specific stands structured in terms of relative basal area of tree species? (ii) What are the levels of CD and CA in the stem component of tree species in the mono- and multi-specific stands? (iii) Which vegetation characteristics strongly account for the variations in CD and CA in the tree species in the mono- and multi-specific stands? We established 15 stands (six mono- and nine multi-specific stands), each having 4ha area in the forest region. Total number of species across the stands was 46 belonging to 25 families. Average tree density ha-1 and stem basal area (BA, m2ha-1), across the stands were 522 and 11.1, respectively. Margalef's index of species richness (SR), Whittaker's index of species evenness (Ew) and Shannon-Wiener index (H') were greater at multi-specific stands compared to mono-specific stands. Average wood specific gravity (WSG) across species for the mono-specific (Teak) was greatest compared to the other categories. Across the mono- and multi-specific stands, WSG among species ranged between 0.47 and 0.79gcm-3, with 26.2% having WSG≥0.70gcm-3. Across the plots in mono- and multi-specific stands, stem density showed positive correlation with BA and aboveground stem biomass (AGB). The associations of SR with Ew and H', and Ew with H' were significantly positive. The AGB was positively associated with SR, Ew and BA. Repeated measures ANOVA indicated significant effects of year, stand and species for DBH, height and AGB. Average aboveground CD and CA across the stands were 136t-Cha-1 and 5.3t-Cha-1yr-1, respectively. Results of step-wise multiple regression indicated that across the stands, CD was influenced by BA and H', and CA was affected by SR and BA. Principal component analysis exhibited strong association of CA and CD with multi-specific stands compared to mono-specific stands. Teak and Sal trees showed maximum CA per unit BA at multi-specific stand compared to mono-specific stand. These findings can be used by the forest managers to increase the carbon density and accumulation in Teak and Sal forests of India. © 2014.

Kumari M.,Banaras Hindu University | Tripathi B.D.,Banaras Hindu University
International Journal of Environmental Science and Technology | Year: 2015

The present work deals with a promising approach for the removal of heavy metals from secondary treated wastewater using aquatic plants, which are economic and effective in separating metals from polluted water. Since the conventional sewage treatment processes were inefficient to remove heavy metals from wastewater, batch experiments of Phragmites australis, Typha latifolia and P. australis and T. latifolia grown in association and reference (unplanted) were carried out for 15 days of retention time for the removal of copper (Cu), cadmium (Cd), chromium (Cr), nickel (Ni), iron (Fe), lead (Pb), and zinc (Zn) from the secondary treated effluent. Significantly, higher removal of the heavy metals in planted set than the reference revealed role of plants in their removal (analysis of variance, p < 0.05). Higher removal of Cr, Fe, and Zn (66.2 ± 3.5, 70.6 ± 1.2, and 71.6 ± 3.9 %) in the combination of the P. australis and T. latifolia than their individual culture suggested synergistic effect of both the plants in the removal of these metals. Positive relationship was observed between retention time and the removal of heavy metals. Mass balance equation has revealed that the loss of heavy metals in wastewater was equivalent to the net accumulation of heavy metals in plant and loss of heavy metals in natural degradation. P. australis showed higher accumulative capacities for Cu, Cd, Cr, Ni, Fe, and Pb than those of T. latifolia. The P. australis and T. latifolia grown in association might be utilized for the heavy metal removal in the tropical environment. © 2013, Islamic Azad University (IAU).

Banerjee G.,Banaras Hindu University
Clean Technologies and Environmental Policy | Year: 2012

Owing to lack of rational basis, design of radial collector (RC) well often becomes a confusing task for the designers arising out of a wide difference between the anticipated yield and the observed yield from RC wells. In this study, a long-term pumping test was carried out at three different sites (near Kharagpur City, India) on Kasai river bed and in its close proximity in order to design subsurface RC well for water supply to Kharagpur City. The appropriate hydrological approaches were employed to estimate values of aquifer parameters, viz. storage coefficient (S) and coefficient of transmissibility (T) for the aforesaid sites under study, which were found to be in the ranges of 0.00129-0.068 and 810-2573 m3/day-m, respectively. This article reports the rationality of design methods of sub-surface RC well, based on image theory and model study, which was adequately supported with geophysical investigations. An RC well-system was designed following the aforesaid two methods and was constructed at the proposed Site-II, which was found to be the most favourable one based on remote sensing survey, geophysical studies, and hydrological investigations. In the trial operating stage of the RC well, commissioned at Site II, the observed yield was compared with the designed (predicted) values. Trial field (yield) test data at Site II showed that the designed yield of 24 million litres per day (MLD) based on model study was closer to field data (21 MLD) than that (8 MLD) obtained based on image theory. © Springer-Verlag 2011.

Verma M.,Banaras Hindu University
Natural Resource Modeling | Year: 2016

The overexploitation of wildlife species is a serious problem in the field of biodiversity conservation. The species subjected to natural Allee effects are even more threatened by exploitation. Moreover, for many wildlife species, their rarity can fuel their exploitation by making them disproportionately desirable and consequently increasing their market price. In this paper, a mathematical model is proposed and analyzed to study how the value that consumers place on rarity can threaten the survival of a species subjected to natural Allee effects. It is assumed that the value of a species increases as its density declines. The analysis of model shows that the increase in the consumers' response to rarity can drive the system to admit Hopf-bifurcation and heteroclinic bifurcation. The occurrence of the heteroclinic cycle indicates that the increase in consumers' response to rarity can cause the extinction of the species. It is found that an increase in the Allee threshold causes a decrease in the threshold value of consumers' response below which extinction is inevitable. Copyright © 2016 Wiley Periodicals, Inc.

Agrawal N.K.,Banaras Hindu University | Sharma B.,Banaras Hindu University
Archives of Osteoporosis | Year: 2013

Bone mineral density was studied in 200 healthy Indian men above 50 years age, without fractures or osteoporosis. Mean vitamin D was 18.96 ng/ml; other biochemical evaluations were normal. Bone density (femur neck) decreased with age; there was osteoporosis in 8.5 %, osteopenia in 42 %, while 49.5 % were normal. Vitamin D deficiency may have caused osteoporosis. Purpose: Osteoporosis is recognized as the disease of females; however, males are also affected and have serious consequences thereof. The present study aimed at studying the prevalence of osteoporosis in otherwise healthy Indian males aged 50 years or more and studying the factors affecting bone mineral density (BMD). Methods: With informed consent, 200 healthy males aged 50 years or more without the history of fractures or diseases affecting the BMD were evaluated clinically (including anthropometry) and biochemically (serum calcium, phosphate, alkaline phosphatase, creatinine, albumin, 25-OH Vitamin D, intact parathyroid hormone (iPTH), and testosterone). The BMD was measured by single observer on Lunar DPX-NT at right proximal femur for least effects of artifacts. Calculation of T score and categorization as osteoporosis, osteopenia, and normal BMD was done as per WHO classification. Results: The mean age was 62.61 ± 7.64 years, and BMI was 23.90 ± 3.73 kg/m2. The testosterone levels were normal in 84 % subjects. The mean 25-OH vitamin D level was 18.96 ± 10.23 ng/ml; only 13.5 % subjects had normal levels. The mean iPTH level was 72.60 ± 43.77 pg/ml; 57 % subjects had normal iPTH (12-72 pg/ml). The other parameters studied were normal. The osteoporosis and osteopenia were more prevalent when BMD was evaluated at neck of femur (osteoporosis 8.5 vs 8 % at trochanter and 7.5 % at total right hip; osteopenia 42 vs 37 % at trochanter and 41 % at total right hip). The BMD deteriorated with age. Conclusion: The osteoporosis affects 8.5 % of otherwise healthy males aged 50 years and above. Vitamin D deficiency is common in such group and maybe responsible for osteoporosis. © 2013 International Osteoporosis Foundation and National Osteoporosis Foundation.

Sharma Y.C.,Banaras Hindu University
Journal of Chemical and Engineering Data | Year: 2011

Adsorption characteristics of a low-cost activated carbon, rice husk activated carbon (RHAC), for the removal of malachite green (MG), a basic dye from aqueous solutions, have been investigated. Rice husk is peel-off from paddies and is a well-known agricultural waste material. Characterization of the activated carbon was carried out using different sophisticated methods. RHAC was characterized by Fourier transformation infrared spectrometry (FTIR), scanning electron microscopy (SEM), X-ray diffractometry (XRD), and thermogravimetric analysis (TGA). A nitrogen adsorption isotherm study revealed that the RHAC possessed micropores and mesopores. The porous properties of activated carbon were determined, and its surface area was found to be 180.50 m2/g. The RHAC was used for the removal of MG from its aqueous solutions. The effect of initial concentration and contact time, temperature, and pH on the removal of MG was investigated. The removal of MG decreased from (94.91 to 93.75) % by increasing the initial dye concentration from (60 to 100) mg/L. A study of the effect of temperature revealed the process of removal of dye to be endothermic. Kinetic studies of the process of adsorption were also carried out. The experimental data were used to study the Langmuir and Frendulich adsorption isotherms. © 2011 American Chemical Society.

Singh V.P.,Banaras Hindu University | Singh S.,Banaras Hindu University
Acta Crystallographica Section E: Structure Reports Online | Year: 2010

The title compound, C 15H 15N 3O, was obtained by a condensation reaction between o-amino-acetophenone and benzoyl hydrazine. The molecule displays an E configuration about the C=N bond. Intra-molecular N - H⋯N hydrogen bonds are formed between the 2-amino-phenyl and imine groups. In the crystal, dimers are formed between molecules linked by intermolecular N - H⋯O hydrogen bonds from the 2-amino-phenyl group. In addition there are intermolecular N - H⋯O hydrogen bonds between the amine and carbonyl groups of adjacent molecules. The molecule is twisted rather than planar due to a steric inter-action between the central amide group and the two outer benzene rings. The dihedral angles between this central group and the two rings are 23.29 (9) and 24.96 (9)°. © 2010.

In this paper, the approximate analytical solutions of BenneyLin equation with fractional time derivative are obtained with the help of a general framework of the reduced differential transform method (RDTM) and the homotopy perturbation method (HPM). RDTM technique does not require any discretization, linearization or small perturbations and therefore it reduces significantly the numerical computation. Comparing the methodology (RDTM) with some known technique (HPM) shows that the present approach is effective and powerful. The numerical calculations are carried out when the initial conditions in the form of periodic functions and the results are depicted through graphs. The eight different cases have studied and proved that the method is extremely effective due to its simplistic approach and performance. © 2011 Elsevier Ltd. All rights reserved.

Pathak R.S.,Banaras Hindu University
International Journal of Wavelets, Multiresolution and Information Processing | Year: 2011

Translation and convolution associated with the discrete wavelet transform are investigated using properties of Calderón-Zygmund operator and Riesz fractional integral operator. Dual convolution is also studied. The wavelet convolution is applied to approximate functions belonging to certain L p-spaces. © 2011 World Scientific Publishing Company.

Tripathi M.M.,Banaras Hindu University
Differential Geometry and its Application | Year: 2011

We present Chen-Ricci inequality and improved Chen-Ricci inequality for curvature like tensors. Applying our improved Chen-Ricci inequality we study Lagrangian and Kaehlerian slant submanifolds of complex space forms, and C-totally real submanifolds of Sasakian space forms. © 2011 Elsevier B.V.

Srivastava G.,Banaras Hindu University | Kayastha A.M.,Banaras Hindu University
PloS one | Year: 2014

Fenugreek (Trigonella foenum-graecum) seeds do not contain starch as carbohydrate reserve. Synthesis of starch is initiated after germination. A β-amylase from ungerminated fenugreek seeds was purified to apparent electrophoretic homogeneity. The enzyme was purified 210 fold with specific activity of 732.59 units/mg. Mr of the denatured enzyme as determined from SDS-PAGE was 58 kD while that of native enzyme calculated from size exclusion chromatography was 56 kD. Furthermore, its identity was confirmed to be β-amylase from MALDI-TOF analysis. The optimum pH and temperature was found to be 5.0 and 50°C, respectively. Starch was hydrolyzed at highest rate and enzyme showed a Km of 1.58 mg/mL with it. Antibodies against purified Fenugreek β-amylase were generated in rabbits. These antibodies were used for localization of enzyme in the cotyledon during different stages of germination using fluorescence and confocal microscopy. Fenugreek β-amylase was found to be the major starch degrading enzyme depending on the high amount of enzyme present as compared to α-amylase and also its localization at the periphery of amyloplasts. A new finding in terms of its association with protophloem was observed. Thus, this enzyme appears to be important for germination of seeds.

Singh A.,Banaras Hindu University | Singh B.N.,Banaras Hindu University
Behavioural Processes | Year: 2013

Intra- and interspecific variations in female and male remating frequency, latency, and duration of copulation in first and second matings were analyzed in four species of the Drosophila bipectinata complex, employing four strains of each species i.e. D. bipectinata, D. parabipectinata, D. malerkotliana and D. pseudoananassae. Chi-square test revealed significant intraspecific variation in the number of remated females and males in D. malerkotliana and D. bipectinata, whereas D. parabipectinata showed insignificant intraspecific variations in number of remated females and males. D. pseudoananassae showed significant intraspecific variation in the number of remated females, but the frequency of remating was least. One way ANOVA depicted significant intraspecific variation in female and male remating time in D. bipectinata and D. parabipectinata. D. bipectinata took the shortest time to remate and the duration of copulation in first mating was longest. However, D. pseudoananassae exhibited the longest remating time and long duration of copulation in first mating. Results of t-test depicted that all four species exhibited shorter duration of copulation in second mating as compared to the first. Our study puts D. bipectinata and D. pseudoananassae at two extremes, and D. parabipectinata and D. malerkotliana at an intermediate position in a hierarchy of remating behaviours. © 2013 Elsevier B.V.

Srivastava P.,Banaras Hindu University | Kumar P.,Banaras Hindu University | Singh K.,Banaras Hindu University
Journal of Nanoparticle Research | Year: 2011

Manipulation of carrier spins in semiconductors for spintronics applications has received great attention driven by improved functionalities and higher speed operation. Doping of semiconductor nanocrystals by transition-metal ions pronounced as diluted magnetic semiconductors (DMS) has attracted tremendous attention. Such doping is, however, difficult to achieve in low-dimensional strongly quantum-confined nanostructures by conventional growth procedures. In the present case, magic-sized, pure, and Cr-doped CdS DM-QDs have been synthesized by solution phase chemistry (lyothermal method). Structural, optical, and magnetic investigation suggest an intrinsic nature of ferromagnetism with highly quantum-confined system. Optical and magnetic results of pure and doped QDs reveal major physical consequences of dopant localization within the capacity to engineer dopant-carrier exchange interactions introducing magnetic functionalities within the host semiconductor lattice. Unpaired Cr ions in Cd substitutional sites could create spin ordering and ferromagnetic coupling. The results presented herein illustrate some of the remarkable and unexpected complexities that can arise in doped QDs. © 2011 Springer Science+Business Media B.V.

Shahid M.,Banaras Hindu University | Srivastava P.,Banaras Hindu University | Misra A.,Banaras Hindu University
New Journal of Chemistry | Year: 2011

A fluorescent bischromophoric dyad combining anthracene and naphthalic anhydride units has been synthesized and characterized. The dyad shows a FRET mediated emission signal at ∼535 nm when excited at λex. = 380/360 nm, with efficient energy transfer efficiency (ET = 93%) and quantum yield (Φ = 0.155). Upon interaction with F- and Hg 2+ ions selectively, a diminished (switched-Off) FRET signal is observed and the naked-eye sensitive color of the solution changed to dark red with enhanced emission corresponding to an anthracene moiety (switched-On). Job's plot analysis revealed a 1:1 stoichiometry between dyad and F -/AcO- and Hg2+ ions. The output fluorescence signals exhibited by dyad on chemical inputs of F-, AcO- and Hg2+ ions mimicked OR, XNOR and INHIBIT logic functions. A 1H NMR titration experiment suggested deprotonation of -NH proton and "Y-type or tweezer-like" H-bonding interaction in the presence of F- and AcO-, respectively, involving -NH, -CHN- and anthracene ring protons. © 2011 The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.

Singh A.K.,Banaras Hindu University | Quraishi M.A.,Banaras Hindu University
Journal of Applied Electrochemistry | Year: 2011

The inhibition effect of ceftobiprole against the corrosion of mild steel in 1 M HCl solution was studied by weight loss, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization and atomic force microscopy techniques. Inhibition efficiency increased with inhibitor concentration where as decreased with acid concentration. Data obtained from EIS studies were analyzed to model the corrosion inhibition process through appropriate equivalent circuit models. The adsorption of ceftobiprole obeyed Langmuir adsorption isotherm. Both thermodynamic and activation parameters were calculated and discussed. Polarization curves indicated that they are mixed type of inhibitors. Polarization curves showed that ceftobiprole act as mixed-type inhibitor. The results obtained from weight loss, EIS and Potentiodynamic polarization are in good agreement. © Springer Science+Business Media B.V. 2010.

Singh M.P.,Banaras Hindu University | Singh R.K.,Banaras Hindu University
Fluid Phase Equilibria | Year: 2011

Ultrasonic velocity, density, viscosity and surface tension of ionic liquids 1-butyl-3-methyl imadazolium hexafluorophosphate [BMIM][PF 6], 1-butyl-3-methyl imadazolium octyl sulfate [BMIM][OcSO 4] and 1-ethyl-3-methyl imadazolium methane sulfonate [EMIM][MeSO 3] have been measured from 303K to 333K. Using these experimental data, inter relationships among ultrasonic velocity, density, viscosity and surface tension have been examined for these ionic liquids. It has been found that (a) ultrasonic velocity (u), surface tension (σ) and density (ρ) can be correlated linearly using equation, logu=ψlog σ/ρ+ξ (with typical values of ψ=1.61 and ξ=10.459) (b) surface tension is linearly correlated with viscosity by the relation ln σ=lna+bη -0.125, where ln a and b are constants. These correlations among physicochemical properties of the ionic liquids can be used to evaluate the properties (viz. ultrasonic velocity) not available in literature. © 2011 Elsevier B.V.

Hasan S.H.,Banaras Hindu University | Srivastava P.,Banaras Hindu University
Industrial and Engineering Chemistry Research | Year: 2011

The present study deals with the successful utilization of bacterial biosorbent Arthrobacter sp. for the removal of Cd(II) ion from water in a batch and a continuous system. The maximum uptake capacity of free and immobilized biomass in batch system was 270.27 and 188.67 mg/g, respectively. The maximum removal percentage Cd2+ of 88.9% was obtained at flow rate of 1.0 mL/min and 19 cm bed height in the column system. The bed depth service time (BDST) model was applied, which was found to be in good agreement with the experimental data with high correlation coefficient (>0.997) and low chi-square value (>1.62). Thomas and Yoon-Nelson models were also applied to the experimental data, and the Yoon-Nelson model provided a better description of experimental kinetic data in comparison to the Thomas model. Column regeneration studies were also carried out using 0.1 mol/L HCl as desorbent for seven sorption-desorption cycles. Furthermore, an attempt has been made to optimize the process conditions for the maximum removal using the central composite design, and the result predicted by optimization plots was 89.64%, which is close to the experimental data, that is, 88.9% at the same process conditions. © 2010 American Chemical Society.

Tiwari S.,Banaras Hindu University | Chand Mishra P.,Banaras Hindu University
Journal of Molecular Modeling | Year: 2011

The photoisomerization of urocanic acid (UCA)-which is present in human skin epidermis, where it acts as a sunscreen-from its trans isomer to its cis isomer upon exposure to UV-B radiation is known to cause immunosuppression. In recent years, the antioxidant properties of UCA (it acts as a hydroxyl radical scavenger) have also been recognized. In view of this, the mechanisms of stepwise reactions of trans-UCA with up to four hydroxyl radicals were investigated. The molecular geometries of the different species and complexes involved in the reactions (reactant, intermediate and product complexes, as well as transition states) were optimized via density functional theory in the gas phase. Solvation in aqueous media was treated with single point energy calculations using DFT and the polarizable continuum model. Single point energy calculations in the gas phase and aqueous media were also carried out using second-order Møller-Plesset perturbation theory (MP2). The AUG-cc-pVDZ basis set was employed in all calculations. Corrections for basis set superposition error (BSSE) were applied. Vibrational frequency analysis was performed for each optimized structure to ensure the validity of the optimized transition states. It was found that the binding of the first OH· radical to UCA involves a positive energy barrier, while subsequent reactions of OH· radicals are exergonic. Transition states were successfully located, even in those cases where the barrier energies were found to be negative. The cis-trans isomerization barrier energy of UCA and that of the first OH· radical addition to UCA are comparable, meaning that both processes can occur simultaneously. It was found that UCA could serve as an antioxidant in the form of an efficient OH· radical scavenger. © 2010 Springer-Verlag.

Prasanna Kumari N.K.,Banaras Hindu University | Jagannadham M.V.,Banaras Hindu University
Colloids and Surfaces B: Biointerfaces | Year: 2011

The molten globule state can be an intermediate in the protein-folding pathway and its detailed description can help understand the protein folding and an insight into the molecular structure of a protein. Sodium dodecyl sulfate (SDS), an anionic surfactant is known to induce molten globule sate in some proteins. SDS-induced changes in heynein were monitored by CD, fluorescence, 8-anilino-1-napthalenesulfonic acid (ANS) binding and proteolytic activity measurements. An enhancement in the α-helicity of protein with increasing concentration of SDS along with exposure of tryptophans is seen. At a concentration of SDS (∼2. mM) heynein loses activity and rigid tertiary structure but possesses considerable amount of secondary structure along with strong ANS binding, indicating the presence of an intermediate state, which is like molten globule state seen in the case heynein. Chemical and temperature induced unfolding of SDS-induced state of heynein is non-cooperative contrary to the protein in the absence of detergent. Further, the cooperative unfolding transition curve of heynein in the absence of SDS intersects at a point where the second transition of SDS-induced state starts suggesting that the molecule of heynein consist of at least two structural domains which are stabilized differentially and unfolds sequentially. Enhancement of α-helicity of heynein in the presence of SDS suggests the α-rich domain of the protein was stabilized and unfold later as compared with β-rich domain during temperature and chemical induced denaturation. Equilibrium unfolding pathway of heynein in SDS-induced state provides knowledge of the structure and stability of this plant cysteine protease at domain level. © 2010 Elsevier B.V.

Pandey D.,Banaras Hindu University | Agrawal M.,Banaras Hindu University | Bohra J.S.,Banaras Hindu University
Agriculture, Ecosystems and Environment | Year: 2012

Global agriculture lies in intersection of two inescapable issues of the present times, viz. keeping pace with growing food demand and participating in climate change mitigation efforts. Rice cultivation is a major emitter of greenhouse gases (GHGs) and no tillage of soil is becoming popular due to low economic investments with improved soil conditions. However, how these arrangements will affect GHG emissions need to be quantified. Therefore, monitoring over diverse agricultural practices is essential for optimum utilization of cultivable land and resources, while identifying the chances of emission reductions. We assessed the impacts of four tillage practices in rice-wheat cultivation system on fluxes of GHGs (CH 4, N 2O and CO 2) and yield of rice. The tillage practices were tilling of soil before sowing of every crop (RCT-WCT), tillage before sowing of rice but no tillage before sowing of wheat (RCT-WNT), tillage before sowing of wheat but no tillage before sowing of rice (RNT-WCT), and no tillage before sowing of rice as well as wheat (RNT-WNT). Reduction in tillage frequency led to significant reductions in fluxes of CH 4 and N 2O, but increased CO 2 while permutations of tillage and no tillage influenced grain yield. RNT-WCT produced next to or comparable to the most yielding RCT-WCT. Although it is difficult to select the best performer since no single tillage permutation showed consistent increment in yield with accompanied emission reductions, RNT-WCT, however may be considered as better agricultural practice for the study region. Long term and extensive spatio-temporal monitoring is still required before making any recommendation. It is also essential for understanding the factors that cause declination in yields under no tillage. © 2012 Elsevier B.V.

Prasad B.B.,Banaras Hindu University | Kumar D.,Banaras Hindu University | Madhuri R.,Banaras Hindu University | Tiwari M.P.,Banaras Hindu University
Electrochimica Acta | Year: 2011

A new class of composite electrodes made of sol-gel derived ceramic-multiwalled carbon nanotubes is used for the growth of a nanometer thin film adopting "surface grafting-from approach". For this the multiwalled carbon nanotubes-ceramic electrode surface is first modified with an iniferter (benzyl N,N-diethyldithiocarbamate) and then dopamine imprinted polymer, under UV irradiation, for differential pulse anodic stripping voltammetric sensing of dopamine in aqueous, blood serum, cerebrospinal fluid, and pharmaceutical samples (detection limit 0.143-0.154 ng mL-1, 3σ), without any cross reactivity, interferences and false-positive contributions. Such composite electrodes offer higher stability, electron kinetics, and renewable porous surface of larger electroactive area (with insignificant capacitance) than carbon ceramic electrodes. Additional cyclic voltammetry (stripping mode) and chronocoulometry experiments were performed to explore electrodics and kinetics of electro-oxidation of dopamine. © 2011 Elsevier Ltd. All rights reserved.

Nair R.R.,Banaras Hindu University | Khanna A.,Banaras Hindu University | Singh K.,Banaras Hindu University
Reproductive Sciences | Year: 2012

Recurrent early pregnancy loss (REPL) is a multifactorial disorder as both genetic and environmental factors contribute to the development of disease. Folate metabolism is an important mechanism to ensure proper fetal growth. Hyperhomocysteinemia leads to a number of disorders and REPL is one of them. In a case-control study DNA from 106 cases with the history of 3 or more REPL and 140 healthy fertile controls with successful pregnancy outcomes were genotyped for C677T single-nucleotide polymorphism (SNP) of the MTHFR (methylenetetrahydrofolate reductase) gene through polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), which was further confirmed by sequencing. Allele frequencies of REPL cases were compared with healthy controls and a statistically significant association was found between REPL and the mutant T allele (χ 2 = 8.786, odds ratio [OR] = 2.20, 95% confidence interval [CI] = 1.323-3.9658, P =.003). The genotype frequencies of SNP C677T also differ significantly between these 2 groups (χ 2 = 8.237, P =.016). The OR for heterozygous CT in the REPL versus controls is 1.9591 (95% CI = 1.0285-3.7318, P =.04). The OR for TT homozygous is 6.3009 (95% CI = 1.2065, P =.02). Combined odds ratio of CT and TT against the control has been calculated as 2.2194 (95% CI = 1.2029-4.0952, P =.02) which is also significant. Thus the present study clearly indicates that homozygosity and heterozygosity for the MTHFR C677T polymorphism confer a 6.3009- and 1.9591-fold increased risk of idiopathic REPL, respectively. © The Author(s) 2012.

Sundar S.,Banaras Hindu University | Chakravarty J.,Banaras Hindu University
Expert Opinion on Pharmacotherapy | Year: 2015

Introduction: Leishmaniasis broadly manifests as visceral leishmaniasis (VL), cutaneous leishmaniasis (CL) and mucocutaneous leishmaniasis. The treatment of leishmaniasis is challenging and the armamentarium of drugs is small, duration of treatment is long, and most drugs are toxic. Areas covered: A literature search on treatment of leishmaniasis was done on PubMed. Single dose of liposomal amphotericin B (L-AmB) and multidrug therapy (L-AmB + miltefosine, L-AmB + paromomycin (PM), or miltefosine + PM) are the treatment of choice for VL in the Indian subcontinent. A 17-day combination therapy of pentavalent antimonials (Sbv) and PM remains the treatment of choice for East African VL. L-AmB at a total dose of 18 - 21 mg/kg is the recommended regimen for VL in the Mediterranean region and South America. Treatment of CL should be decided by the severity of clinical lesions, etiological species and its potential to develop into mucosal leishmaniasis. Expert opinion: There is an urgent need to implement a single-dose L-AmB or combination therapy in the Indian subcontinent. Shorter and more acceptable regimens are needed for the treatment of post - kala-azar dermal leishmaniasis. Combination therapy with newer drugs needs to be tested in Africa. Due to the toxicity of systemic therapy, a trend toward local treatment for New World CL is preferred in patients without risk of mucosal disease. © 2015 Informa UK, Ltd. All rights reserved.

Nath G.,Banaras Hindu University | Maurya P.,Banaras Hindu University
International Journal of Antimicrobial Agents | Year: 2010

Fluoroquinolone-resistant Salmonella enterica subspecies enterica serotype Typhi are being increasingly reported from the Asian subcontinent. This has been hypothesised to be due to a double mutation in the gyrA gene. A total of 113 S. Typhi strains isolated during 1987-2006 in a tertiary-level hospital of North India were monitored for their antibiotic susceptibility by the disk diffusion and minimum inhibitory concentration (MIC) methods. The study period was arbitrarily divided into four equal parts, each comprising 5 years. The antibiotics tested showed an extremely wide range of MICs during all four periods except for ceftriaxone, which showed no resistance during the study period. However, a gradual increase in the MIC of this drug was observed, i.e. 0.047. mg/L, 0.098. mg/L, 0.211. mg/L and 0.3652. mg/L during the four study periods. Ninety-one percent of the strains isolated in the final study period were observed to have MIC levels ≥0.125. mg/L to ciprofloxacin. Furthermore, g. yrA restriction analysis showed no mutation at the two reported sites of the gene, suggesting that the double mutation theory in the development of ciprofloxacin resistance may not be the only mechanism responsible for fluoroquinolone resistance. © 2010 Elsevier B.V. and the International Society of Chemotherapy.

Mukherjee A.,Banaras Hindu University | Haldar C.,Banaras Hindu University
Journal of Photochemistry and Photobiology B: Biology | Year: 2014

Photoperiodic modulation of melatonin membrane receptor (MT1R) expression in testis has never been reported for any seasonal breeder. Thus, the aim of the present study was to investigate the expression dynamics of MT1R in testis and its interaction with testicular steroidogenesis in a long-day breeder, Mesocricetus auratus. Hamsters were exposed to different photoperiodic conditions i.e. critical- (CP; 12.5L:11.5D); short-day- (SD; 8L:16D) and long-day- (LD; 16L:8D) for 10 weeks wherein testicular steroidogenesis, local melatonin synthesis and the expression of MT1R were analyzed. SD induced melatonin suppressed testicular steroidogenesis as evident from regressed testicular histoarchitecture, decreased expression of AR, StAR, LH-R, P450SCC and enzyme activities of 3β- and 17β-HSD. Differential photoperiodic regulation of MT1R expression in testis suggests its involvement in photoperiodic signal transduction for seasonal adjustment of reproduction. Increased S-NAT (Serotonin N-acetyl transferase) activity and local testicular melatonin under SD condition suggest an inhibitory effect of the local melatonergic system on testicular steroidogenesis. Completely opposite responses were recorded for all the parameters analyzed when hamsters were exposed to CP or LD conditions. In conclusion, we may suggest that photoperiod via regulating circulatory and local melatonin level as well as MT1R expression in testes fine tunes the steroidogenesis and thereby, the reproductive status of male golden hamster. © 2014 Elsevier B.V. All rights reserved.

Shah K.,Banaras Hindu University | Nahakpam S.,Banaras Hindu University
Plant Physiology and Biochemistry | Year: 2012

A 0-500 μM Cd2+ alone and/or heat stress in rice cv. DR-92 (sensitive) and cv. Bh-1 (tolerant), altered the banding patterns of SOD, CAT, POD and APX enzymes in roots/shoots. In controls, six/seven activity bands for POD in roots/shoots were observed. The band intensities of some decreased under combination of Cd2+ + heat stress. Six SOD isoforms in shoots of cv. Bh-1 and three in cv. DR-92 appeared. In sensitive cv. DR-92 a trinuclear Cu/Zn/Mn-SOD 1 isozyme was upregulated in shoots under Cd/HS/Cd + HS treatments whereas a suppression in the same was noticed in roots. Under Cd alone the Cu/Zn/Mn-SOD 2 was strongly induced in roots which was otherwise absent in all HS treatments. POD R7 band was absent in HS alone but was induced under Cd2+ + HS treatments in rice cv. DR-92. In tolerant cv. Bh-1, isozyme Mn-SOD 3 was induced under Cd alone but was absent under HS. Cu/Zn/Mn-SOD 2 and Cu/Zn/Mn-SOD 3 were strongly induced in roots and shoots under low or moderate Cd2+ + HS treatments. APX R4/CATR2 isozymes which were absent under Cd2+ alone or HS alone were induced under combination of Cd2+ + HS indicating de novo synthesis of enzyme proteins under combined stressors. Decreased band intensities under Cd2+ + HS suggest a cross-talk between response pathways of Cd2+ and heat stress in rice. Results suggest Cd2+ specific, heat-specific, tissue specific and differential expression of SOD/POD/APX/CAT and that Mn-SOD 3/APXR4/CATR2 seem to form important components of antioxidant defense in rice roots under combination of Cd2+ + HS which helps to mitigate the effect of low Cd2+ toxicity in tolerant rice cv. Bh-1. © 2012 Elsevier Masson SAS.

Gupta S.,Banaras Hindu University | Haldar C.,Banaras Hindu University
Journal of Steroid Biochemistry and Molecular Biology | Year: 2013

Immunoenhancing attributes of melatonin (Mel) on the immunocompromised state induced by glucocorticoid is well known, but the involvement of their receptors in the modulation of immunity has never been studied in any rodent. The present study explores the role of Mel and its receptors (MT1 and MT2) in amelioration of immunocompromised state induced by a synthetic glucocorticoid, dexamethasone (Dex) in a tropical rodent Funambulus pennanti. Immune parameters viz. DTH response, Lymphocyte proliferation, cytokine (IL-2) and antibody production were assessed following pretreatment of Mel and Dex alone or in combination. Mel enhanced the IL-2 production, thymic and splenic lymphocyte proliferation thereby increasing T helper cell associated immune responses and anti-KLH-IgG production. MT1 and MT2 receptor expression was downregulated following Dex treatment while glucocorticoid receptors (GR) expression was downregulated in Mel treated groups suggesting that the immunomodulatory effects of glucocorticoids and Mel are mediated via their receptors. To gain further insights on the role of Mel receptors, we used nonselective melatonin receptor antagonist luzindole which resulted in reversal of most of the immunomodulatory actions of Mel. Therefore, it may be suggested that a physiological cross talk exist between Mel and GR which is of high adaptive significance in wild animals for balancing the immunity during ecologically stressful conditions. © 2012 Elsevier Ltd.

Sharma R.,Banaras Hindu University | Vinayak M.,Banaras Hindu University
Molecular Biology Reports | Year: 2013

Increased level of ROS causes oxidative stress and leads to various pathological conditions including cancer. Therefore antioxidants should contribute to cancer prevention by improving antioxidant defense system and thereby protecting the cell from oxidative damage. In the present study we have validated the hypothesis by evaluating the antioxidant action of α-tocopherol. The effect of α-tocopherol is analyzed on oxidative stress as well as its regulation on antioxidant defense system. Oxidative stress is measured in terms of reduced glutathione and protein carbonylation. To evaluate the role of α-tocopherol on antioxidant defense system, the activities and expressions of antioxidant enzymes like glutathione peroxidase, catalase and superoxide dismutase are analyzed by activity gel assay and by RT-PCR respectively. These enzyme activities and/or expressions are found to be improved by α-tocopherol in lymphoma bearing mice which brings down the oxidative stress as reflected by increased level of reduced glutathione as well as decreased protein carbonylation. The effect of α-tocopherol is further analyzed on general characteristics of lymphoma growth like body weight, longevity, accumulation of ascites fluid, angiogenesis in peritoneum, morphology of liver and abundance of lymphocytes. The antioxidant α-tocopherol is found to check lymphoma growth. The results suggest that α-tocopherol contributes to lymphoma prevention by improving antioxidant defence system of mice. © 2012 Springer Science+Business Media Dordrecht.

Mishra S.,Banaras Hindu University | Vinayak M.,Banaras Hindu University
Molecular Biology Reports | Year: 2013

Protein Kinase C (PKC) isozymes are key components involved in cell proliferation and their over activation leads to abnormal tumor growth. PKC follows signalling pathway by activation of downstream gene NF-kB and early transcription factor c-Myc. Over activation of NF-kB and c-Myc gene are also linked with unregulated proliferation of cancer cells. Therefore any agent which can inhibit the activation of Protein kinase C, NF-kB and c-Myc may be useful in reducing cancer progression. To investigate this hypothesis we have tested the effect of ellagic acid on these genes in Dalton's lymphoma bearing (DL). The role of ellagic acid was also tested in regulation of tumor suppressor gene Transforming growth factor-β1 (TGF-β1). DL mice were treated with three different doses (40, 60 and 80 mg/kg body weight) of ellagic acid. Ascites cells of mice were used for the experiments. Ellagic acid administration to DL mice decreased oxidative stress by reducing lipid peroxidation. Ellagic acid also down regulates the expression of classical isozymes of PKC i.e. PKCα, PKCβ, and PKCγ as well as activity of total PKC and NF-kB, indicating its antitumor action. The anticarcinogenic action of ellagic acid was also confirmed by up regulation of TGF-β1 and down regulation of c-Myc. Lymphoma prevention by ellagic acid is further supported by decrease in cell proliferation, cell viability, ascites fluid accumulation and increase in life span of DL mice. All these findings suggest that ellagic acid prevents the cancer progression by down regulation of PKC signaling pathway leading to cell proliferation. © 2012 Springer Science+Business Media Dordrecht.

Gupta R.K.,Banaras Hindu University | Kanungo M.,Banaras Hindu University
Age | Year: 2013

Glial cells, besides participating as passive supporting matrix, are also proposed to be involved in the optimization of the interstitial space for synaptic transmission by tight control of ionic and water homeostasis. In adult mouse brain, inwardly rectifying K+ (Kir4.1) and aquaporin-4 (AQP4) channels localize to astroglial endfeets in contact with brain microvessels and glutamate synapses, optimizing clearance of extracellular K+ and water from the synaptic layers. However, it is still unclear whether there is an age-dependent difference in the expressions of Kir4.1 and AQP4 channels specifically during postnatal development and aging when various marked changes occur in brain and if these changes region specific. RT-PCR and immunoblotting was conducted to compare the relative expression of Kir4.1 and AQP4 mRNA and protein in the early and mature postnatal (0-, 15-, 45-day), adult (20-week), and old age (70-week) mice cerebral and cerebellar cortices. Expressions of Kir4.1 and AQP4 mRNA and protein are very low at 0-day. A pronounced and continuous increase was observed by mature postnatal ages (15-, 45-days). However, in the 70-week-old mice, expressions are significantly up-regulated as compared to 20-week-old mice. Both genes follow the same age-related pattern in both cerebral and cerebellar cortices. The time course and expression pattern suggests that Kir4.1 and AQP4 channels may play an important role in brain K+ and water homeostasis in early postnatal weeks after birth and during aging. © 2011 American Aging Association.

Sukla K.K.,Banaras Hindu University | Raman R.,Banaras Hindu University
European Journal of Clinical Nutrition | Year: 2012

Background/Objectives: Unlike most Western populations, MTHFR 677T is a rare allele and a risk factor for a variety of disorders in India. What kind of nutritional (environmental) and/or genetic factors could contribute to the genetic risk is not known. To assess the incidence of hyperhomocysteinemia and its correlation with the polymorphism in homocysteine (Hcy)-pathway genes and associated cofactors in the native populations of eastern India. Subjects/Methods: Healthy population from four eastern states of India. Genotyping of SNPs, HPLC and chemiluminescence-based assay for homocysteine, vitamin B12 and folic acid. Results: Approximately 30% of the population has hyperhomocysteinemia (>15 μmol/lit; hypHcy) with varying frequencies in the four states from where samples were collected (n1426). Polymorphisms of MTR and CBS do not affect hypHcy. 677T and 1298C alleles of MTHFR and G80 RFC-1 show association with hypHcy. In contrast, RFC-1 80AA is protective even in presence of 677T MTHFR. Addition of each mutant allele has an additive effect on Hcy level. Vitamin B12 (cofactor in methionine synthesis) clearly modulates the genotypic effect on Hcy level. Although frequency of individuals with low folic acid is ∼ 11, 49% of the population is vitamin B12 deficient (<220 pg/lit) and has a significant negative correlation with Hcy. Individuals with optimum vitamin B 12 and folic acid generally have low Hcy, even in risk genotypes.Conclusions:One of the plausible reasons for susceptibility of individuals with MTHFR C677T in the studied population to various disorders is the high frequency of hyperhomocysteinemia and vitamin B12 deficiency in the healthy population. Apparently, supplementation of vitamin B 12 to this health-impoverished community may help lessen the risk of several multifactorial disorders. © 2012 Macmillan Publishers Limited All rights reserved.

Goswami S.,Banaras Hindu University | Haldar C.,Banaras Hindu University
British Journal of Dermatology | Year: 2014