Time filter

Source Type

Basant N.,Environmental and Technical Research Center | Gupta S.,CSIR - Central Electrochemical Research Institute
Nanotoxicology | Year: 2017

The metal oxide nanoparticles (MeONPs) due to their unique physico-chemical properties have widely been used in different products. Current studies have established toxicity of some NPs to human and environment, hence, imply for their comprehensive safety assessment. Here, the potential of using a multi-target QSTR modeling for simultaneous prediction of multiple toxicity endpoints of various MeONPs has been investigated. A multi-target QSTR model has been established using four different experimental toxicity data sets of MeONPs. Diversity of the considered experimental toxicity data sets was tested using the Kruskal–Wallis (K–W) statistics. The optimal validated model yielded high correlations (R2 between 0.828 and 0.956) between the experimental and simultaneously predicted endpoint toxicity values in test arrays for all the four systems. The structural features (oxygen percent, LogS, and Mulliken’s electronegativity) identified by the QSTR model were mechanistically interpretable in view of the accepted toxicity mechanisms for NPs. Single target QSTR models were also established (R2 Test >0.882) for individual toxicity endpoint prediction of MeONPs. The performance of the multi-target QSTR model was closely comparable with individual models and with those reported earlier in the literature for toxicity prediction of NPs. The model reliably predicts the toxicity of all considered MeONPs, and the methodology is expected to provide guidance for the future design of safe NP-based products. The proposed multi-target QSTR can be successfully used for screening new, untested metal oxide NPs for their safety assessment within the defined applicability domain of the model. © 2017 Informa UK Limited, trading as Taylor & Francis Group

Manju S.,CSIR - Central Electrochemical Research Institute | Sagar N.,CSIR - Central Electrochemical Research Institute
Renewable and Sustainable Energy Reviews | Year: 2017

Fossil fuels such as coal, petroleum, and natural gas have been used as the major sources of energy in the recent past. However, the negative environmental impacts associated with the emission of the greenhouse gases from these conventional energy sources forced to realize the importance of renewable energy resources. At the same time, the average annual exponential rate of population growth in India needs increasing amounts of fresh-water for the basic necessities. This might result in water scarcity as the overall population in India is expected to increase to 1.60 billion by 2050. It has been forecasted that, by the year 2040, India will rank 40th in the world in terms of water scarcity. To meet the rising fresh-water demand, desalination is an intelligent and sustainable option for India, which has a very long coastline measuring 7517 km. In this paper, an attempt has been made to provide a comprehensive review of water scarcity in India and suggest a possible solution, which is implementing desalination technologies coupled with renewable resources. The paper reviews the ground water scenario in India and the global desalination market. We summarize the energy consumption in various desalination processes and provide a brief outlook of the desalination techniques in India. Apart from this, desalination using non-conventional sources such as solar, wind, and geothermal energy is discussed. In addition, factors affecting the environment due to desalination and the potential counter measures are presented. This review aims to provide an awareness of the projected water crisis in India, in the coming decades, and is also aimed to help the policy makers for selecting an appropriate desalination technology. © 2017 Elsevier Ltd

Das D.,CSIR - Central Electrochemical Research Institute | Chakraborty T.K.,Indian Institute of Science
Organic Letters | Year: 2017

Diastereoselective approaches toward the synthesis of a marine-derived sesquiterpenoid fungal metabolite, asperaculin A, are delineated, combining step economy and simplicity. Two distinct lactonization sequences from a common intermediate led to the first synthesis of 9-deoxyasperaculin A, a novel dioxa[]fenestrane, in 14 steps (16% overall yield) and 16 steps (18% overall yield), respectively. [2,3]-Wittig-Still rearrangement and Ti(III)-mediated epoxide opening-cyclization were employed as some of the key steps for the stereoselective generation of the vicinal all-carbon quaternary centers of the target molecule. © 2017 American Chemical Society.

Neog K.,CSIR - Central Electrochemical Research Institute | Dutta D.,CSIR - Central Electrochemical Research Institute | Das B.,Indian Institute of Technology Guwahati | Gogoi P.,CSIR - Central Electrochemical Research Institute
Organic Letters | Year: 2017

A novel transition-metal-free direct synthesis of 3-substituted isocoumarin from 4-hydroxycoumarin and a benzyne precursor is developed. This synthetic strategy proceeds via C-O and C-C bond cleavage as well as C-O and C-C bond formations in a single reaction vessel by simple treatment with CsF in the absence of catalyst. This methodology affords moderate to good yields of 3-substituted isocoumarins and is tolerant of a variety of functional groups including halide. © 2017 American Chemical Society.

Mandal P.,CSIR - Central Electrochemical Research Institute
Tectonophysics | Year: 2017

We herein present shear velocity structure extending down to 300 km depth below the Archean Singhbhum-Odisha Craton (SOC) and Proterozoic Chotanagpur granitic-gneissic terrain (CGGT), which has been obtained through the inversion modeling of P-receiver functions. We use three-component broadband recordings of 200 teleseismic earthquakes (30° ≤ ∆ ≤ 90°) from a 15 station seismic network that has been operational in the Eastern Indian shield since February 2013. We obtain the thinnest crust of 35 km overlying a thin lithosphere of 78 km, below the region near south Singhbhum shear zone, which could be attributed to the 1.6 Ga plume activity associated with Dalma volcanic. However, the thickest crust of 47 km overlying a thin lithosphere of 81 km is noticed below the region near the Singhbhum granite of 3.6 Ga. This thinning of lithosphere could be attributed to the delamination of lithospheric root due to the Himalayan orogeny with a shortening rate of 2 cm/year. This delamination model in SOC gets further support from the densification of the lower crust, which could result from repeated episodes of basaltic underplating associated with episodes related to Dalma (~ 1.6 Ga) and Rajmahal (~ 117 Ma) volcanisms. This led to relatively more mafic, heterogeneous and deformed crustal structure in SOC as well as EGMB (with an average crustal Vs of 4.0 km/s) in comparison to that in CGGT (with an average crustal Vs of 3.9 km/s), as seen through our modeling results. The thickest lithosphere of 100 km is observed in the southwestern SOC as well as northeastern CGGT. We also notice that a sharp and flat Moho in CGGT, which could be attributed to thermal reactivation and large volume melting of the mafic cratonic crust during the late Archean subduction process and associated volcanism episodes. This model gets further support from the estimated 169 km thick lower Vs zone in the upper mantle below CGGT. Our modeling results also support a northward subduction of Archean SOC under the Proterozoic CGGT during 1.0–1.6 Ga, as earlier proposed by the geological age data from the region. © 2017 Elsevier B.V.

Dawalbhakta M.,CSIR - Central Electrochemical Research Institute | Telang M.,CSIR - Central Electrochemical Research Institute
Recent Patents on Biotechnology | Year: 2017

Background: Saffron (Crocus sativus L.) has a long history of use as a food additive and a traditional medicine for treating a number of disorders. Prominent bioactives of saffron are crocin, crocetin and safranal. Objective: The aim of this study was to carry out an extensive patent search to collect information on saffron bioactives and their derivatives as therapeutic and cosmeceutical agents. All patents related to the area of interest published globally till date have been reviewed. Moreover, a recent synthetic biology approach to cost effective and consistent production of saffron bioactives has been highlighted. Methods: A patent search strategy was designed based on keywords and concepts related to Crocus sativus L. and its bioactives-safranal, crocin and crocetin in combination with different patent classification codes relevant to the technology areas. This search strategy was employed to retrieve patents from various patent databases. The patents which focused on therapeutic or cosmetic applications and claimed compositions comprising crocin, crocetin or safranal as the main active component were selected and analysed. Results: Maximum patenting activity was noticed towards the use of these bioactives in the treatment of neurological disorders followed by multiple uses of the same compound, use in treatment of metabolic disorders and use as cosmeceuticals. Interestingly, there were no patent records related to use of these bioactives in treating infectious disorders. Conclusion: Our patent analysis points out the populous and less explored uses of saffron bioactives and areas where there is further scope for research and growth. Recently developed synthetic biology approach is contributory in improving availability, consistency and cost effectiveness of saffron bioactives. © 2017 Bentham Science Publishers.

Punetha P.,CSIR - Central Electrochemical Research Institute | Mohanty P.,CSIR - Central Electrochemical Research Institute | Samanta M.,CSIR - Central Electrochemical Research Institute
Geotextiles and Geomembranes | Year: 2017

Interface shear strength between soil and geosynthetics mainly depends on the mechanical and physical properties of soil, geosynthetics and the normal stress acting at the interface. This paper presents results of an extensive experimental investigation carried out on sand-geosynthetic interface using modified large direct shear box. The study focusses on the shearing mechanism at the sand-geosynthetic interface and the effect of different parameters on the shearing mechanism. Smooth HDPE geomembrane, nonwoven needle punched geotextile and two types of sand having different mean particle size, have been used in the present study. Microstructural investigation of deformed specimen through Field Emission Scanning Electron Microscope (FESEM) reveals the shearing mechanism which includes interlocking and fiber stretching for sand-geotextile while sliding, indentation and plowing for sand-geomembrane interface. The shearing mechanism for sand-geomembrane interface highly depends on the normal stress and degree of saturation of sand. The critical normal stress that demarcates the sliding and plowing mechanism for sand-geomembrane interface is different for dry and wet sand. The amount of scouring (or plowing) of the geomembrane surface reduces with increase in the mean particle size of sand. FESEM images revealed that the sand particles get adhered to the geotextile fibers for tests involving wet sands. The present microstructural study aided in understanding the shearing mechanism at sand-geosynthetic interface to a large extent. © 2017 Elsevier Ltd.

Chandrasekaran S.S.,CSIR - Central Electrochemical Research Institute | Murugan P.,CSIR - Central Electrochemical Research Institute
Applied Surface Science | Year: 2017

First principles density functional calculations are carried out to investigate the structural, electronic, and electrochemical properties of the bilayered nanocomposite, which is composed of LiMPO4 (M =Fe and Co) as a positive electrode and γ-Li3PO4 as a solid-state electrolyte. The calculated interfacial energy reveals that the Li-O atomic layer terminated (010) LiMPO4 surface gives better stability than its Fe-O layer termination, for constructing the solid state interface with γ-Li3PO4. Further, structural optimization shows that inter-layer distances at the interface and surface of the electrolyte are increased ≈0.1 and 0.06Å, respectively, from its bulk value. Moreover, electronic structure calculations infer that the energy of top most occupied level in the electrode strongly depends on its thickness, whereas, this energy is almost constant for different thick electrolytes. Thus, our study suggests that by varying the thickness of LiMPO4-electrode, Li-ion vacancy formation and electrochemical performance of the nanocomposite can be altered favourably. © 2017 Elsevier B.V.

Rajkumar,CSIR - Central Electrochemical Research Institute
Optics InfoBase Conference Papers | Year: 2016

Diffraction-Lloyd mirror interferometer is used to generate different portions of the hyperboloid two-beam fringes in single interferogram. Diffraction at an optical fiber generates beam with large divergence and hence full circular fringes along-with other shapes. © OSA 2016.

Upadhyay S.K.,CSIR - Central Electrochemical Research Institute
Biopolymers | Year: 2017

The thermodynamics of DNA-ligand binding is important as it provides useful information to understand the details of binding processes. HIV-1 REV response element (RRE) located in the env coding region of the viral genome is reported to be well conserved across different HIV-1 isolates. In this study, the binding characteristics of Calf thymus DNA (ctDNA) and REV peptide from HIV-1 were investigated using spectroscopic (UV–visible, fluorescence, and circular dichroism (CD)) and isothermal titration calorimetric (ITC) techniques. Thermal stability and ligand binding properties of the ctDNA revealed that native ctDNA had a Tm of 75.5 °C, whereas the ctDNA–REV peptide complex exhibited an incremental shift in the Tm by 8 °C, indicating thermal stability of the complex. CD data indicated increased ellipticity due to large conformational changes in ctDNA molecule upon binding with REV peptide and two binding stoichiometric modes are apparent. The ctDNA experienced condensation due to large conformational changes in the presence of REV peptide and positive B→Ψ transition was observed at higher molar charge ratios. Fluorescence studies performed at several ligand concentrations revealed a gradual decrease in the fluorescence intensity of EtBr-bound ctDNA in response to increasing ligand concentrations. The fluorescence data further confirmed two stoichiometric modes of binding for ctDNA–REV peptide complex as previously observed with CD studies. The binding enthalpies were determined using ITC in the temperature range of 293 K–308 K. The ITC binding isotherm was exothermic at all temperatures examined, with low ΔH values indicating that the ctDNA–REV peptide interaction is driven largely by entropy. The heat capacity change (ΔCp) was insignificant, an unusual finding in the area of DNA-peptide interaction studies. The variation in the values obtained for ΔH, ΔS, and ΔG with temperature further suggests that ctDNA–REV peptide interaction is entropically driven. ITC based analysis of salt dependence of binding constant gave a charge value (Z) = +4.01, as determined for the δlnK/δln[Na+] parameter, suggesting the participation of only 3–4 Arg out of 11 Arg charge from REV peptide. The stoichiometry observed for the complex was three molar charge of REV peptide binding per molar charge of ctDNA. ITC based analysis further confirmed that the binding between ctDNA and REV peptide is governed by electrostatic interaction. Molecular interactions including H-bonding, van der Waals forces, and solvent molecules rearrangement, underlie the binding of REV peptide to ctDNA. © 2016 Wiley Periodicals, Inc.

Krishnakumar S.,Indian National Institute for Interdisciplinary Science and Technology | Gopidas K.R.,Indian National Institute for Interdisciplinary Science and Technology | Gopidas K.R.,CSIR - Central Electrochemical Research Institute
Langmuir | Year: 2017

A simple method for covalent functionalization of Fréchet-type dendron nanoparticles (FDNs) using tris-bipyridylruthenium(II) is described. Covalent functionalization is achieved by chemically reducing the diazo derivative of a ruthenium(II)bipyridine complex in the presence of FDNs wherein the radical species generated gets covalently linked to the nanoparticle surface. Simplicity, rapidity, and robustness are the advantages offered by the present approach. The nanoparticles, post functionalization, were characterized using transmission electron microscopy, thermogravimetric analysis, and infrared, energy-dispersive X-ray, UV-visible, and nuclear magnetic resonance spectroscopic techniques. Depending on the solvent, the ruthenium complex-linked FDN displays a range of morphologies, including nanoparticles, fiber-networks, and nanocapsules. In the nanocapsules and fiber-networks observed in organic solvents, the ruthenium complex is confined within the interior domain of the aggregate, whereas in the nanoparticles observed in water, it is present on the periphery. The formation of predictable morphologies in different solvents plays a key role in using such self-assembled structures for various applications such as sensing, catalysis, and light harvesting. Characterization of these nanoaggregates using different spectroscopic and microscopic techniques is also described. © 2017 American Chemical Society.

Hemalatha T.,CSIR - Central Electrochemical Research Institute | Ramaswamy A.,Indian Institute of Science
Journal of Cleaner Production | Year: 2017

The use of fly ash in concrete dates back to the late 20th century and its advantages and disadvantages had been widely researched. Despite the broad based research carried out across the globe in utilizing fly ash as a cement replacement material in concrete, the level of replacement is still limited to a maximum of 35% of cement by mass. In view of increasing the level of fly ash replacement in cement to minimize the carbon footprint, this work summarizes the following: firstly, the current state of fly ash applications in concrete by considering about 200 papers published since 1980 to till date. Secondly, the analysis of form-structure-property of fly ash reported in various literature and its correlation with strength and durability characteristics. Thirdly, the contradictions reported in literature regarding the performance of fly ash, particularly, in the context of shrinkage, high temperature curing, water demand etc. Overall, this review brings to light that, apart from chemical composition, the influence of other factors such as morphology, crystallinity, size etc. have major influence in altering the hydration mechanism which in turn bring changes in mechanical and durability properties of fly ash concrete. The critical examination of properties of fly ash provides insight for wider utilization of fly ash, facilitating a higher replacement of cement possibly upto 60% in a scientific way rather than by trial and error basis. Further, this review recommends for the classification of fly ash apart from the existing ASTM classification of fly ash as Class F and Class C. Furthermore, amendments in existing codes are recommended for high volume utilization of fly ash. © 2017 Elsevier Ltd

Shakilanishi S.,Vellore Institute of Technology | Chandra Babu N.K.,CSIR - Central Electrochemical Research Institute | Shanthi C.,Vellore Institute of Technology
Journal of Cleaner Production | Year: 2017

Chrome shavings (chromium complexed collagenous waste scrapings), one of the major proteinous solid wastes of leather industry are posing a pollution threat. Recovery and reuse of protein component of the waste can prevent their disposal as landfills. In the present work, the collagen hydrolysate derived from chrome shavings was screened as an inexpensive protein source in comparison with agro based protein wastes for the cost-effective production of dehairing protease. The chrome shavings used in the study were obtained during processing of goat skins. Maximum enzyme production of 203 ± 0.07 U/mL by Bacillus cereus VITSN04 was observed with the formulated medium (pH 8.0) containing, 12 g/L of collagen hydrolysate from chrome shavings, 15 g/L of molasses, 3 g/L of K2HPO4, 2 g/L of NaCl and 0.04 g/L of CaCl2. Fluorescence spectral analysis confirmed that collagen hydrolysate stabilized the protease and prolonged its activity. The protease was purified with a yield of 88.1% using 22% (w/v) of 2-propanol and 14% (w/v) of K2HPO4 aqueous two phase system. The purification and activity of the enzyme was confirmed by native-polyacrylamide gel electrophoresis. The purification yield of protease with aqueous two phase system was much higher than that with ultrafiltration system. Thus, approach made in the present study provides an attractive option for recycling chrome shavings waste as a cheaper protein source in the production of dehairing enzyme for use in cleaner leather processing. © 2017 Elsevier Ltd

Subalakshmi P.,CSIR - Central Electrochemical Research Institute | Sivashanmugam A.,CSIR - Central Electrochemical Research Institute
Journal of Alloys and Compounds | Year: 2017

Transition metal oxides (TMO) with admirable theoretical capacity acquired by their conversion reaction have been studied extensively as anode materials for Li-ion batteries. In the current inquisition, Cuo nano hexagons are synthesized by rapid hydrothermal method and characterized through various analytical techniques viz XRD, FESEM, TEM, FT-IR, and XPS analysis. Electrochemical cycling performance of CuO as anode material for Li-ion batteries is elucidated at different current densities between 215 mA g−1 and 4.3 A g−1. Nano CuO anode exhibits stable discharge performance of ∼575 mAh g−1 at current density of 215 mA g−1 with low irreversible capacity of 265 mA g−1 in the first cycle which is lesser than several reported values obtained from different nano morphological CuO and composites of CuO with conducting additives. Further, nano CuO anode exhibits high rate capability up to the current density of 4.3 A g−1 and resumes the initial capacity of 572 mAh g−1 at 215 mA g−1 current density and remains stable even beyond 100 cycles with zero capacity fading. These ensuing performance characteristics demonstrate nano CuO as a prospective anode material for lithium ion battery. © 2016 Elsevier B.V.

Rao E.V.S.P.,CSIR - Central Electrochemical Research Institute
CAB Reviews: Perspectives in Agriculture, Veterinary Science, Nutrition and Natural Resources | Year: 2015

Diversification of agriculture to support livelihoods and protect the environment has attracted the attention of scientists and policy makers. Aromatic plants have been considered as diversification crops in agricultural systems in many parts of the world. Aromatic plants synthesize secondary metabolites in the form of essential oils as a response to environmental and biotic stresses. These essential oils can be used in a variety of economic applications such as perfumes, flavours and fragrances as well as in pharmaceuticals, and provide additional economic returns to farmers. There is growing scientific evidence from different parts of the world suggesting that integration of aromatic crops in agricultural systems improves land use efficiencies as well as economic returns. The roles that aromatic plants play in ecological applications-such as soil erosion control, improvement of soil properties, carbon sequestration, phyto-remediation, utilization of low-quality irrigation waters and pest and disease management-have gained significance in agriculture. The present review discusses the role of aromatic plants in economic agriculture and in ecological services. © 2015 CAB International.

Deka Boruah H.P.,CSIR - Central Electrochemical Research Institute
Indian Journal of Experimental Biology | Year: 2017

North East region of India suffers from high sulphur coal mine overburden (OB) and plants those survive under such condition have adopted to such harsh environment. Here, we have investigated the effect of coal mine OB substrate on biochemical, physiological and growth of two shrubs Cassia (Cassia sofera L.) and Dhaincha (Sesbania rostrata L.); two tree species Gomari (Gmelina arborea L.) and Sisso (Dalbergia sisso L.); and two monocots Citronella Grass (Cymbopogon winterianus Jowitt) and Lemon Grass (Cymbopogon citratus L). The mine OB was found to be acidic (pH 2.0) with no true soil behavior, 12.5% sulphur and more than double the trace and heavy metals compared to normal control soil. Overall, high lipid peroxidation, membrane damage, peroxidase, glutathione reductase, ascorbate peroxidase, superoxide dismutase enzymes activities along with osmolyte proline and total soluble sugar was found in mine OB plants compared to control plants. While antioxidant activities were higher, nitrate reductase activity was significantly low but reduced leaf area, total shoot and root biomass. However, the responses of antioxidant activities in mine OB plants and control plants did not follow a standard pattern of higher activities in roots followed by old>young leaves or vice versa. Further, in mine OB plants, lipid peroxidation was found significantly higher for young citronella leaves. The levels of higher glutathione reductase was found in roots than the leaves except for old leaves in Gomari while ascorbate peroxidase was found in the leaves than the roots. Overall, all the species showed higher antioxidant enzyme activities, osmolyte accumulation and membrane damage possibly due to acidity and significantly higher limit of trace and heavy metals in mine OB substrate. © 2017, National Institute of Science Communication. All rights reserved.

Singh V.P.,CSIR - Central Electrochemical Research Institute | Katta S.,CSIR - Central Electrochemical Research Institute | Kumar S.,CSIR - Central Electrochemical Research Institute
BMC Cancer | Year: 2017

Background: WDR13 is a member of the WD repeat protein family and is expressed in several tissues of human and mice. Previous studies in our laboratory showed that the lack of this gene in mice resulted in mild obesity, hyperinsulinemia, enhanced beta cell proliferation and protection from inflammation. However, the molecular mechanism of WDR13 action is not well understood. Methods: In the present study, we used AOM/DSS to induce colitis-mediated colorectal tumor after establishing expression of Wdr13 gene in colon. Further, we have used human colon cancer cell lines, HT29 and COLO205, and mouse primary embryonic fibroblast to understand the molecular mechanism of WDR13 action. Results: We observed that mice lacking Wdr13 gene have reduced number of tumors and are more susceptible to DSS-induced colon ulcers. We also show that WDR13 is a part of multi protein complex c-Jun/NCoR1/HDAC3 and it acts as a transcriptional activator of AP1 target genes in the presence of JNK signal. Consistent with in vitro data, we observed reduced expression of AP1 target genes in colon after AOM/DSS treatment in Wdr13 knockout mice as compared to that in wild type. Conclusion: Mice lacking Wdr13 gene showed reduced expression of AP1 target genes and protection from colitis-induced colorectal tumors. © 2017 The Author(s).

Ravinder R.,Indian Institute of Technology Indore | Goyal N.,CSIR - Central Electrochemical Research Institute
Gene | Year: 2017

LIM domains are zinc-binding motifs that mediate protein–protein interactions and are found in a wide variety of cytoplasmic and nuclear proteins. The nuclear LIM domain family members have a number of different functions including transcription factors, gene regulation, cell fate determination, organization of the cytoskeleton and tumour formation exerting their function through various LIM domain interacting protein partners/cofactors. Nuclear LIM domain interacting proteins/factors have not been reported in any protozoan parasites including Leishmania. Here, we report for the first time cloning, characterization and subcellular localization of nuclear LIM interactor-interacting factor (NLI) like protein from Leishmania donovani, the causative agent of Indian Kala-azar. Primary sequence analysis of LdNLI revealed presence of characteristic features of nuclear LIM interactor-interacting factor. However, leishmanial NLI represents a distinct kinetoplastid group, clustered in a separate branch of the phylogenic tree. The sub-cellular distribution of LdNLI revealed the discreet localization in nucleus and kinetoplast only, suggesting that the gene may have a role in parasite gene expression. © 2017 Elsevier B.V.

Shukla J.,CSIR - Central Electrochemical Research Institute
Optics InfoBase Conference Papers | Year: 2016

The paper presents theoretical study for enhancement of sensitivity for long period grating based surrounding refractive index sensors. The sensitivity has been enhanced by the coating of high refractive index material than the cladding. © OSA 2016.

Kumar A.,Delhi Technological University | Saini T.S.,CSIR - Central Electrochemical Research Institute
Optics InfoBase Conference Papers | Year: 2016

We report the supercontinuum generation spanning 2 μm-13 μm in a few-mode step index fiber of 10mm length pumped with 50 fs laser pulses of 4 kW peak power at 3.1μm pump wavelength. © OSA 2016.

Gogoi G.,CSIR - Central Electrochemical Research Institute | Hazarika S.,CSIR - Central Electrochemical Research Institute
Separation and Purification Technology | Year: 2017

The work demonstrates the pretreatment of lignocellulosic biomass (Rice straw) in imidazolium based ionic liquids. Three different imidazolium based ionic liquids, 1-ethyl-3-methyl–imidazolium acetate, 1-methyl-3-octylimidazolium chloride and 1-butyl-3-methyl-imidazolium tetrafluoroborate were used to dissolve the lignocelluloses of rice straw and the dissolution process was optimised under several conditions viz. time, temperature and particle size of biomass. The dissolution process was investigated by characterizing the biomass before and after treatment by FTIR, XRD, SEM and Zeta Potential analysis. From the pretreated lignocelluloses, cellulose and lignin were separated using chemical methods. On the basis of investigations, the role of ionic liquids on dissolution of lignocelluloses and effect of different imidazolium based ionic liquids for the regeneration of cellulose and lignin were discussed. After the separation process ionic liquid was recovered using nano filtration membrane and was reused for further study. © 2016 Elsevier B.V.

Prawin J.,Academy of Scientific and Innovative Research | Rao A.R.M.,Academy of Scientific and Innovative Research | Rao A.R.M.,CSIR - Central Electrochemical Research Institute
Mechanical Systems and Signal Processing | Year: 2017

Most of the practical engineering structures exhibit nonlinearity due to nonlinear dynamic characteristics of structural joints, nonlinear boundary conditions and nonlinear material properties. Meanwhile, the presence of non-linearity in the system can lead to a wide range of structural behavior, for example, jumps, limit cycles, internal resonances, modal coupling, super and sub-harmonic resonances, etc. In this paper, we present a Volterra series approximation approach based on the adaptive filter concept for nonlinear identification of multi-degree of freedom systems, without sacrificing the benefits associated with the traditional Volterra series approach. The effectiveness of the proposed approach is demonstrated using two classical single degrees of freedom systems (breathing crack problem and Duffing Holmes oscillator) and later we extend to multi-degree of freedom systems. © 2016 Elsevier Ltd

Prakash A.,CSIR - Central Electrochemical Research Institute | Srinivasan S.M.,Indian Institute of Technology Madras | Rama Mohan Rao A.,CSIR - Central Electrochemical Research Institute
Materials and Structures/Materiaux et Constructions | Year: 2017

The application of fibre composites in the construction of protective structures for impact and blasts is an active area of research. Important mechanical properties like compressive strength, tensile strength, flexural toughness, acoustic impedance, mass density, ultrasonic pulse velocity, are required to determine the high velocity impact (HVI) resistance of the cementitious composite target panels. However, the above mechanical properties of steel fibre reinforced cementitious composites (SFRCC) for varying fibre volume fraction are difficult to find in existing literature. This paper presents results of an extensive experimental study, conducted to characterize the SFRCC for varied fiber volume fractions between 0 and 12 %. Hooked end steel fibres having an aspect ratio about 66 (fibre length 30 mm diameter 0.45 mm) are used in the preparation of control specimens. Important engineering properties like, compressive, tensile, and flexural strengths, toughness and acoustic impedances are determined through the laboratory tests. A total of 250 numbers standard cylinder, cube, prism and dog-bone specimens are prepared for the characterization of steel fibre reinforced cementitious composite. The significance of the present study in impact resistance applications is also demonstrated through the HVI tests on SFRCC panels. This study highlights various aspects related to judicious selection of materials in layered cementitious composite targets. © 2016, RILEM.

Subalakshmi P.,CSIR - Central Electrochemical Research Institute | Ganesan M.,CSIR - Central Electrochemical Research Institute | Sivashanmugam A.,CSIR - Central Electrochemical Research Institute
Materials and Design | Year: 2017

CuO micro balls and nano hexagons have been synthesized by time, cost effective rapid hydrothermal and precipitation methods respectively. Physical characterization is explained through various analytical techniques. Electrochemical performance of CuO as an active material for super capacitor application in 6 M KOH solution is illustrated. CuO micro balls exhibit specific capacitance of about 470 F g− 1 where as CuO nano hexagons exhibit only 103 F g− 1 at current density of 0.5 A g− 1. The superior electrochemical performance of CuO micro balls is attributed to 3D micro structure assembled from nano sheets eventually possess more active sites as evident from larger surface area observed in BET analysis. Further, co-existence of Cu2O phase enhances the electrochemical performance by reversible redox couple CuO/Cu2O and the entrapped hydroxyl group in micro balls increases the conductivity and accelerates the electrode kinetics in alkaline medium. © 2017 Elsevier Ltd

Mittal M.,CSIR - Central Electrochemical Research Institute
Journal of Loss Prevention in the Process Industries | Year: 2017

This article reports the results of an experimental study on explosion pressure measurement in closed vessel deflagration for methane-air mixtures over its entire flammable range at standard pressure and temperature in vessels with variable geometry and size- 20-L spherical, 27-L cubical, 0.8 m3rectangular and 25.6 m3spherical-under quiescent conditions using electric spark (3 J) as ignition source. The outcome of the study is comprehensive data that quantify the dependency of explosion severity parameters on gas concentration and vessel volume. The information is required to quantify the potential severity of an explosion, design the vessels able to withstand an explosion and to design explosion safety measures for installations handling this gas. The data presented include maximum explosion pressure, explosion time and rate of explosion pressure rise in terms of deflagration index over a range of methane-air equivalence ratio (φ: 0.53–1.52). The maximum explosion pressures are: 8.6, 8.4, 8.2 and 8.0 bar in 20-L sphere, 27-L cubical vessel, 0.8 m3rectangular vessel and 25.6 m3sphere, respectively, at φ=1.05. Time to reach the maximum explosion pressure varies from 80 ms in 20-L sphere to 680 ms in 25.6 m3sphere. The deflagration index values are: 82, 84, 86 and 106 bar m/s in 20-L sphere, 27-L cubical vessel, 0.8 m3rectangular vessel and 25.6 m3sphere, respectively, at φ=1.05. The deflagration index increases with increase in size of the test vessel. © 2017 Elsevier Ltd

Murugadoss G.,CSIR - Central Electrochemical Research Institute | Thangamuthu R.,CSIR - Central Electrochemical Research Institute | Senthil Kumar S.M.,CSIR - Central Electrochemical Research Institute
Solar Energy Materials and Solar Cells | Year: 2017

Copper (I) thiocyanate (CuSCN) is a cost-competitive hole selective contact for the emerging organic-inorganic hybrid perovskite solar cells. However, limitation of solvent is the main issue for getting an optimal thickness for pin-hole free selective contacts. We have developed various solvents such as mixture of propylsulfide with chlorobenzene (1:1), isopropanol with methylammonium iodide (10 mg/ml) and propylsulfide + isopropanol (1:2) + MAI (10 mg/ml) for dissolving CuSCN. It was found that perovskite layer was more stable once CuSCN coating laid on the top surface using the propylsulfide + isopropanol (1:2) + MAI (10 mg/ml) solvent than conventional propylsulfide by doctor blade technique. By employing low temperature solution-process techniques, power conversion achieved over 10% under full sun illumination by the proposed mixed solvent. CuSCN continues to offer promise as a chemically stable and straightforward replacement for the commonly used expensive organic hole conductor (2,2’,7,7’-tetrakis-(N,N-di-p-methoxyphenylamine)9,9’-spirobifluorene (Spiro-OMeTAD)). © 2017 Elsevier B.V.

Sharma S.,CSIR - Central Electrochemical Research Institute | Sarma J.N.,Dibrugarh University
Journal of the Geological Society of India | Year: 2017

The analysis of drainage basin morphotectonic indices is applied in assessment of the influence of tectonic activity on thirteen selected drainage basins of the streams having linear courses and flowing over two very prominent regional structures of northeast India, viz. the Belt of Schuppen and the Dauki fault. Such analysis has been made in order to assess the influence of tectonic activity of these structures on the morphology of the drainage basins of those streams.The different morphotectonic indices considered are: Basin elongation ratio, hypsometric integral, steepness index and profile concavity, drainage basin asymmetry, valley floor width to valley height ratio, longitudinal profiles, stream length gradient index and mountain front sinuosity. Results of the analysis of the morphotectonic indices of the drainage basins infer that morphology of both the streams and drainage basins have been influenced by the regional structures and the present tectonic status of these two structures varies from active to slightly active phase. No significant influence of lithology is seen in the distribution pattern of the anomalous knick points along the longitudinal profiles. The study also reveals that presently the state of tectonic activity is not uniform within the same regional structure and the Belt of Schuppen is relatively more active as compared to the Dauki fault. © 2017, Geological Society of India.

Vishnu Prataap R.K.,CSIR - Central Electrochemical Research Institute | Mohan S.,CSIR - Central Electrochemical Research Institute
Chemical Communications | Year: 2017

Herein, we present the electrochemical fabrication of a hydroxide surface-covered nickel-cobalt alloy and its superior catalytic activity towards the electrochemical oxygen evolution reaction in alkaline media. Electrodes were fabricated via the galvanostatic and potentiostatic electrodeposition methods in various electrolytic compositions, in which a nanopyramid-like morphology was obtained under the galvanostatic conditions and a porous structure was obtained under the potentiostatic deposition conditions. The optimized porous electrode shows the overpotential of 1.537 V (η = 307 mV) vs. RHE for the current density of 10 mA cm-2 in 1 M NaOH solution. Comparatively, the porous Ni-Co alloy electrode exhibits a better performance than the other morphologies obtained in this study. Owing to its highly active surface area with porous structures, it promotes the molecular oxygen evolution reaction. ©2017 The Royal Society of Chemistry.

Singh L.P.,CSIR - Central Electrochemical Research Institute | Zhu W.,University of West of Scotland | Howind T.,University of West of Scotland | Sharma U.,CSIR - Central Electrochemical Research Institute
Cement and Concrete Composites | Year: 2017

This paper presents the quantification and nanomechanical properties of calcium silicate hydrate (C-S-H), formed at early stage hydration of tricalcium silicate (major cement phase) in presence of silica nanoparticles (SNPs). SNPs showed dominant nucleation effect at 8 h and pozzolanic effect at 24 h and accelerate the hydration rate (∼83% at 8 h and ∼51% at 24 h) due to the formation of additional C-S-H nuclei. Further, 29Si-NMR and FTIR techniques showed the acceleration in polymerization of silicate chain leading to the formation of tobermorite like structure. Formation of polymerized and crystalline C-S-H gel in presence of SNPs increases the percentage of high density C-S-H (∼40%) and lowers the low density C-S-H (∼52%) at 24 h of hydration, as observed in nanoindentation results. © 2017 Elsevier Ltd

Daniel Ronald Joseph J.,CSIR - Central Electrochemical Research Institute | Prabakar J.,CSIR - Central Electrochemical Research Institute | Alagusundaramoorthy P.,Indian Institute of Technology Madras
Engineering Structures | Year: 2017

The behavior of precast concrete sandwich panels consisting of two thin R/C layers (wythes) separated by an expanded polystyrene core is examined through experiments on prototype panels subjected to four-point bending, for different values of panel thickness and mesh size, with/without either shear-resistant ribs or conventional steel rebars (besides the wire mesh) in the bottom wythe. The test results indicate that all the panels behave as composite member until failure, and the panel behavior is similar to conventional R/C one-way slabs under flexural load. Due to the presence of wire mesh, cracking behavior in terms of number of cracks and crack spacing of concrete sandwich panels is similar to that of ferrocement cracking behavior. Volume ratio and specific surface of reinforcement affect the cracking behavior of concrete sandwich panels similar to that of ferrocement panels. The crack spacing based on predictive models for concrete slab reinforced with wire mesh agrees with the experimental results. Presence/absence of shear-resistant ribs and/or rebars in the bottom wythe significantly affects the flexural behavior of the panels. Presence of conventional rebars in the bottom wythe together with the wire mesh increases the ultimate flexural load capacity of the panels. The load-deflection response of the concrete sandwich panels exhibits trilinear behavior, and is similar to ferrocement behavior under flexural loading. Analytical study includes strength predictions based on conventional R/C beam analysis. © 2017 Elsevier Ltd

Kumar V.,Jubail Industrial College | Yadav S.,CSIR - Central Electrochemical Research Institute
Sensors and Actuators, A: Physical | Year: 2017

Development of a low cost high pressure sensor with reasonable accuracy is always a challenge for researchers and metrologists. During last few decades, these relaxors have extensively been studied and found useful in several applications in capacitors, memories, optical wave guide, detectors, etc. The ferroelectric relaxor exhibits high strain response and high dielectric constant near the transition temperature. These properties attract researcher to use this material as pressure sensor. The present paper describes an effort made to find new application of ferroelectric material as pressure sensor. The present study carried out on pressure and temperature dependent dielectric properties of (1 − x) PbFe2/3W1/3O3–xPbTiO3 binary relaxor systems with x = 0, 0.02, 0.10 and 0.18 in the pressure range from atmospheric pressure to 416 MPa and temperature range from 283 to 323 K. In the present investigation, researchers have optimized the concentration of lead titanate (PT) in lead iron tungstate-lead titanate (PFW-PT) binary system to obtain high pressure coefficient and low temperature coefficient which is a prime requirement for a binary system to be used as a high pressure sensing element. The specimens are prepared by conventional mixed oxide route. The results thus obtained clearly establish the feasibility of use of PFW as pressure sensing element having low temperature and high pressure coefficient in the pressure range 0–416 MPa and temperature range 283–323 K. © 2017 Elsevier B.V.

Samanta M.,CSIR - Central Electrochemical Research Institute
International Journal of Geotechnical Engineering | Year: 2017

Present laboratory study investigated the geomechanical behaviour of cement-stabilised fly ash. Class F fly ash collected from two different power plants in India was used in the study. Fly ash was stabilised with varying proportions of cement up to 10%, added in the ratio of dry weight of fly ash. Effects of addition of cement were evaluated on compacted fly ash–cement mix at optimum moisture content for rest period of 7, 14, 21 and 28 days. Results showed that the hydraulic conductivity of both the fly ash samples decreased by an order in magnitude when added with 10% cement. Effects of rest periods on hydraulic conductivity of cement-stabilised fly ash were found to be insignificant. Unconfined compressive strength of the cement-stabilised fly ash samples increased with increase in the cement content and rest periods, while the compression index of the stabilised samples decreased with increase in cement content. Different geomechanical behaviour was correlated with the microstructural changes in cement-stabilised fly ash, obtained through Field Emission Scanning Electron Microscope (FMSEM). Test results showed that cement stabilisation improved the engineering behaviour of both the fly ash, which may aid in their application as resource geomaterial. © 2017 Informa UK Limited, trading as Taylor & Francis Group

Kumar R.,CSIR - Central Electrochemical Research Institute
Construction and Building Materials | Year: 2017

Coarse aggregate has notable influence on concrete properties. The sustainability in concrete is generally achieved through reduced mining of natural resources required for the manufacturing of its basic constituents, by recycling of suitable industrial by-products or post-consumer materials including construction and demolition waste (CDW). CDW is composed of several materials depending on its locality of the origin. Recycled concrete aggregate (RCA) is obtained by crushing the concretized components of CDW. RCA is inhomogeneous with respect to its dynamic properties unlike natural coarse aggregate (NCA). A pavement concrete has to possess a proper strength and adequate abrasion resistance to resist surface wearing due to a moving traffic. This study presents the influence of using RCA as a replacement of NCA in paving concrete. Two series of concrete mixes, at two different water-cement ratios, that is, 0.44 and 0.38, were used in this study. The study exhibited that RCA reduces the abrasion resistance significantly yet it could be effectively used in pavement concrete. © 2017

Suman S.,Indian Institute of Information Technology Allahabad | Mishra A.,Indian Institute of Information Technology Allahabad | Kulshrestha A.,CSIR - Central Electrochemical Research Institute
Molecular BioSystems | Year: 2017

Cervical intra-epithelial neoplasia 1 (CIN1) is a pre-cancerous cervical cancer condition characterized by changes in the squamous cells of the cervix. Early detection may facilitate treatment as CIN1 may increase the risk of developing cervical cancer. An extensive system level analysis has been carried out to detect crucial network components of CIN1. Differential expression analysis was performed to identify genes that are differentially expressed in CIN1 in comparison to normal cells. Gene Ontology (GO) and pathway enrichment analyses of DEGs were followed by the construction of a protein-protein interaction (PPI) network. Hubs were identified and module enrichment analysis was performed. A gene regulatory network incorporating DEGs, microRNAs (miRNAs) and transcription factors (TFs) was constructed. To integrate these DEGs with the pathophysiology of CIN1, assessment of interaction of these gene/proteins and crucial motifs with statistical parameters such as z-score and p-value was carried out. Microarray analysis revealed 71 differentially expressed genes including 39 upregulated and 32 downregulated genes. 4 genes, namely PABPC1, RPS27, RPL13A and RPL21, were found to be overlapping among hubs and module genes of the PPI network and also part of the significant motifs of the regulatory network. Gene regulation of the DEGs also revealed important TFs and miRNAs such as ELF1, SRF, has-mir-125b-5p and has-mir-644a. PABPC1, RPS27, RPL13A and RPL21 may serve as potential biomarkers for CIN1 and as prospective targets for therapeutic approaches. Though, further experimental studies are required to confirm our findings. © The Royal Society of Chemistry.

Dhanasekaran M.,CSIR - Central Electrochemical Research Institute | Dhathathreyan A.,CSIR - Central Electrochemical Research Institute
International Journal of Biological Macromolecules | Year: 2017

This work examines fibro-proliferation through interaction of myoglobin (Mb), a globular protein with collagen, an extracellular matrix fibrous protein. Designed colloids of Mb at pH 4.5 and 7.5 have been mixed with collagen solution at pH 7.5 and 4.5 in different concentrations altering their surface charges. For the Mb colloids, 100–200 nm sizes have been measured from Transmission electron micrographs and zeta sizer. CD spectra shows a shift to beta sheet like structure for the protein in the colloids. Interaction at Mb/Collagen interface studied using Dilational rheology, Quartz crystal microbalance with dissipation and Differential Scanning calorimetry show that the perturbation is not only by the charge compensation arising from the difference in pH of the colloids and collagen, but also by the organized assembly of collagen at that particular pH. Results demonstrate that positive Mb colloids at pH 4.5, having more% of entrained water stabilize the collagen fibrils (pH 7.5) around them. Ensuing dehydration leads to effective cross-linking and inherently anisotropic growth of fibrils/fibres of collagen. In the case of Mb colloids at pH 7.5, the fibril formation seems to supersede the clustering of Mb suggesting that the fibro-proliferation is both pH and hydrophilic-hydrophobic balance dependent at the interface. © 2017 Elsevier B.V.

Pal D.,Visva Bharati University | Dasgupta S.,Visva Bharati University | Dasgupta S.,CSIR - Central Electrochemical Research Institute | Kundu R.,Visva Bharati University | And 7 more authors.
Nature Medicine | Year: 2012

Toll-like receptor 4 (TLR4) has a key role in innate immunity by activating an inflammatory signaling pathway. Free fatty acids (FFAs) stimulate adipose tissue inflammation through the TLR4 pathway, resulting in insulin resistance. However, current evidence suggests that FFAs do not directly bind to TLR4, but an endogenous ligand for TLR4 remains to be identified. Here we show that fetuin-A (FetA) could be this endogenous ligand and that it has a crucial role in regulating insulin sensitivity via Tlr4 signaling in mice. FetA (officially known as Ahsg) knockdown in mice with insulin resistance caused by a high-fat diet (HFD) resulted in downregulation of Tlr4-mediated inflammatory signaling in adipose tissue, whereas selective administration of FetA induced inflammatory signaling and insulin resistance. FFA-induced proinflammatory cytokine expression in adipocytes occurred only in the presence of both FetA and Tlr4; removing either of them prevented FFA-induced insulin resistance. We further found that FetA, through its terminal galactoside moiety, directly binds the residues of Leu100g-Gly123 and Thr493g-Thr516 in Tlr4. FFAs did not produce insulin resistance in adipocytes with mutated Tlr4 or galactoside-cleaved FetA. Taken together, our results suggest that FetA fulfills the requirement of an endogenous ligand for TLR4 through which lipids induce insulin resistance. This may position FetA as a new therapeutic target for managing insulin resistance and type 2 diabetes. © 2012 Nature America, Inc. All rights reserved.

Kundu P.,Friedrich Miescher Institute for Biomedical Research | Kundu P.,University of Basel | Fabian M.R.,McGill University | Sonenberg N.,McGill University | And 4 more authors.
Nucleic Acids Research | Year: 2012

The microRNA (miRNA)-mediated repression of protein synthesis in mammalian cells is a reversible process. Target mRNAs with regulatory AU-rich elements (AREs) in their 3′-untranslated regions (3′-UTR) can be relieved of miRNA repression under cellular stress in a process involving the embryonic lethal and altered vision family ARE-binding protein HuR. The HuR-mediated derepression occurred even when AREs were positioned at a considerable distance from the miRNA sites raising questions about the mechanism of HuR action. Here, we show that the relief of miRNA-mediated repression involving HuR can be recapitulated in different in vitro systems in the absence of stress, indicating that HuR alone is sufficient to relieve the miRNA repression upon binding to RNA ARE. Using in vitro assays with purified miRISC and recombinant HuR and its mutants, we show that HuR, likely by its property to oligomerize along RNA, leads to the dissociation of miRISC from target RNA even when miRISC and HuR binding sites are positioned at a distance. Further, we demonstrate that HuR association with AREs can also inhibit miRNA-mediated deadenylation of mRNA in the Krebs-2 ascites extract, in a manner likewise depending on the potential of HuR to oligomerize. © 2012 The Author(s).

Sobana S.,Easwari Engineering College | Panda R.C.,CSIR - Central Electrochemical Research Institute
Reviews in Environmental Science and Biotechnology | Year: 2011

Dissolved salts in seawater or brackish water are reduced to a potable level through separation techniques, like, distillation, multiple effect vapor compression, evaporation, or by membrane processes such as electro-dialysis reversal, nano-filtration, and reverse osmosis (RO). RO is the most widely used desalination process. Recent advances in RO technology has led to more efficient separation and now is the most cost effective process to operate. The performance of the reverse osmosis process is dependent on concentration of dissolved solids in the feed-water, feed-water pressure, and the membrane strength to withstand system pressure, membrane solute rejection, membrane fouling characteristics, and the required permeate solute concentration. RO is a promising tool that uses cellulose acetate (or) polyamide membrane and is widely chosen as the cost of production is reduced by the use of energy efficient and process control techniques. This paper presents a review on modelling, identification of parameters from single input-outputs and multi input/output lumped systems, dynamic modelling and control of desalination systems in the past twenty years by collecting more than 60 literatures. © 2011 Springer Science+Business Media B.V.

Mehra N.K.,Dr Hari Singh Gour University | Verma A.K.,CSIR - Central Electrochemical Research Institute | Mishra P.R.,CSIR - Central Electrochemical Research Institute | Jain N.K.,Dr Hari Singh Gour University
Biomaterials | Year: 2014

Our main aim in the present investigation was to explore the invitro and invivo cancer targeting potential of the doxorubicin (DOX) laden d-α-tocopheryl polyethylene glycol 1000 succinate (vitamin E TPGS) tethered surface engineered MWCNTs nanoformulation (DOX/TPGS-MWCNTs) and compare it with pristine MWCNTs and free doxorubicin solution. The developed MWCNTs nanoformulations were extensively characterized by Fourier-transform infrared, Raman spectroscopy, x-ray diffraction, electron microscopy, and invitro and invivo studies using MCF-7 cancer cell line. The entrapment efficiency was determined to be 97.2±2.50% (DOX/TPGS-MWCNTs) and 92.5±2.62% (DOX/MWCNTs) ascribed to π-π stacking interactions. The developed formulations depicted the sustained release pattern at the lysosomal pH (pH 5.3). The DOX/TPGS-MWCNTs showed enhanced cytotoxicity, cellular uptake and were most preferentially taken up by the cancerous cells via endocytosis mechanism. The DOX/TPGS-MWCNTs nanoconjugate depicted the significantly longer survival span (44 days, p<0.001) than DOX/MWCNTs (23 days), free DOX (18 days) and control group (12 days). The obtained results also support the extended residence time and sustained release profile of the drug loaded surface engineered nanotubes formulations in body as compared to DOX solution. Overall we can conclude that the developed MWCNTs nanoconjugate have higher cancer targeting potential on tumor bearing Balb/c mice. © 2014 Elsevier Ltd.

Goyal R.,CSIR - Central Electrochemical Research Institute | Kumar P.,University of Surrey
Air Quality, Atmosphere and Health | Year: 2013

Three naturally and six mechanically ventilated microenvironments (MEs) of a mix-use commercial building in Delhi are used to study indoor-outdoor (I/O) relationships of particulate matter ≤10 μm (PM10), ≤2.5 μm (PM2.5), and ≤1 μm (PM1). Effect of environmental and occupancy parameters on the concentrations of PM during working and non-working hours (i.e., activity and non-activity periods, respectively) are also investigated. Average outdoor concentration of PM10 and PM2.5 were found to exceed the 24-h averaged national standard values, showing a polluted environment surrounding the studied building. During working hours, indoor PM10 concentration was found 6-10 times, both PM2.5 and PM1 were 1.5-2 times, higher than the non-working hours in the selected MEs. The variations of indoor concentrations were highest (17.1-601.2 μg/m3) for PM10 compared with PM2.5 (16.9-102.6 μg/m3) and PM1.0 (10.6-63.6 μg/m3). The I/O for PM10, PM2.5, and PM1.0 varied from 0.37-3.1, 0.2-3.2, and 0.17-2.9, respectively. The results suggest highest I/O for PM10, PM2.5, and PM1 as 3.1, 2.15, and 1.76, respectively, in all the three natural-ventilated MEs (canteen, kitchen, reception). Irrespective of PM types, the average I/O was <1 for mechanically ventilated MEs compared with >1 for naturally ventilated MEs. As opposed to PM1, better correlation (r > 0.6) was noted between indoor PM10, PM2.5, and CO2 concentrations in most of the airtight MEs. © 2013 Springer Science+Business Media Dordrecht.

Deb G.,University Hospitals Case Medical Center | Deb G.,Indian Institute of Technology Guwahati | Singh A.K.,CSIR - Central Electrochemical Research Institute | Gupta S.,University Hospitals Case Medical Center | And 2 more authors.
Molecular Cancer Research | Year: 2014

Seminal discoveries have established that epigenetic modifications are important for driving tumor progression. Polycomb group (PcG) proteins are highly conserved epigenetic effectors that maintain, by posttranslational modification of histones, the silenced state of genes involved in critical biologic processes, including cellular development, stem cell plasticity, and tumor progression. PcG proteins are found in two multimeric protein complexes called Polycomb repressive complexes: PRC1 and PRC2. Enhancer of zeste homolog 2 (EZH2), catalytic core subunit of PRC2, epigenetically silences several tumor-suppressor genes by catalyzing the trimethylation of histone H3 at lysine 27, which serves as a docking site for DNA methyltransferases and histone deacetylases. Evidence suggests that overexpression of EZH2 is strongly associated with cancer progression and poor outcome in disparate cancers, including hematologic and epithelial malignancies. The regulatory circuit and molecular cues causing EZH2 deregulation vary in different cancer types. Therefore, this review provides a comprehensive overview on the oncogenic role of EZH2 during tumorigenesis and highlights the multifaceted role of EZH2, as either a transcriptional activator or repressor depending on the cellular context. Additional insight is provided on the recent understanding of the causes and consequences of EZH2 overexpression in specific cancer types. Finally, evidence is discussed on how EZH2 has emerged as a promising target in anticancer therapy and the prospects for targeting EZH2 without affecting global methylation status. Thus, a better understanding of the complex epigenetic regulatory network controlling EZH2 expression and target genes facilitates the design of novel therapeutic interventions. © 2014 American Association for Cancer Research.

Lee K.-M.,National Central University | Chiu W.-H.,National Central University | Suryanarayanan V.,CSIR - Central Electrochemical Research Institute | Wu C.-G.,National Central University
Journal of Power Sources | Year: 2013

The present study focuses on enhancing the efficiency of bifacial and back-illuminated dye-sensitized solar cells (DSCs) by incorporating SiO 2 mesoporous layer on TiO2 electrode. The performance of DSCs is investigated by UV-visible spectroscopy, incident photon conversion efficiency (IPCE) and electrochemical impedance spectroscopy (EIS). It is observed that the current ratio of back- to front-DSC increases with the increase in the thickness of SiO2 layer, which in turn influences the incident light to dyed-TiO2 electrode, especially in the wavelength of 400-600 nm. The Ti foil based flexible small (0.28 cm2) and sub-module (5 cm × 10 cm) DSCs having this modification show high conversion efficiencies of 6.76 and 5.54% respectively under 100 mW cm -2 (AM 1.5). © 2012 Elsevier B.V. All rights reserved.

Kind R.,German Research Center for Geosciences | Kind R.,Free University of Berlin | Yuan X.,German Research Center for Geosciences | Kumar P.,German Research Center for Geosciences | Kumar P.,CSIR - Central Electrochemical Research Institute
Tectonophysics | Year: 2012

The lower boundary of the lithospheric plates has remained as an enigmatic boundary for seismologists, since it is relatively poorly observed by seismic means. There is traditionally a broad consensus that the asthenosphere is observable as a low velocity zone by seismic surface waves. Seismic techniques which use shorter period P-to-S or S-to-P converted body waves are now far enough developed to be successful in observing such a low velocity zone with a higher resolution. The principle of this technique (the so-called receiver function technique) is that a strong teleseismic mother phase (e.g. P, S, PP or SKS) incident from below on any seismic discontinuity beneath a station produces a converted phase (Ps or Sp) which indicates its depth and properties. We discuss details of this technique. A sufficient number of such observations exist already to indicate that the top of the low velocity zone is a globally observable discontinuity and it is sharper than previously thought. An intriguing observation is that in some cratons the new seismic data indicate that the low velocity zone exists already at shallower depths than obtained from surface waves. This confirms earlier results from controlled source observations (Thybo and Perchuc, 1997). We discuss possible interpretations of this shallow low velocity zone in cratonic regions. © 2012 Elsevier B.V.

Karthikeyan K.,Chonnam National University | Kalpana D.,CSIR - Central Electrochemical Research Institute | Amaresh S.,Chonnam National University | Lee Y.S.,Chonnam National University
RSC Advances | Year: 2012

Pristine Fe3O4 and Fe3O 4-graphene composites were synthesized by using a green and low cost urea-assisted microwave irradiation method and were utilized as electrode materials for symmetric supercapacitor applications. The Fe3O 4-graphene symmetric cell exhibited a better electrochemical performance than that of the Fe3O4 cell with enhanced rate performances. The Fe3O4-graphene symmetric cell delivered a stable discharge capacitance, energy and power densities of about 72 F g -1, 9 Wh kg-1 and 3000 W kg-1, respectively at 3.75 A g-1 current density over 100/000 cycles between 0-1 V. The impedance studies also suggested that the Fe3O4-graphene symmetric cell showed lower resistance and high conductivity due to the small particle size, large surface area and good interaction between Fe 3O4 particles and graphene layers. © 2012 The Royal Society of Chemistry.

Kumar N.,CSIR - Central Electrochemical Research Institute | Zeyen H.,University Paris - Sud | Singh A.P.,CSIR - Central Electrochemical Research Institute | Singh B.,CSIR - Central Electrochemical Research Institute
Geophysical Journal International | Year: 2013

For the present 2-D lithospheric density modelling, we selected three geotransects of more than 1000 km in length each crossing the southern Indian shield, south of 16°N, in N-S and E-W directions. The model is based on the assumption of local isostatic equilibrium and is constrained by the topography, gravity and geoid anomalies, by geothermal data, and where available by seismic data. Our integrated modelling approach reveals a crustal configuration with the Moho depth varying from ~40 km beneath the Dharwar Craton, and ~39 km beneath the Southern Granulite Terrane to about 15-20 km beneath the adjoining oceans. The lithospheric thickness varies significantly along the three profiles from ~70-100 km under the adjoining oceans to ~130-135 km under the southern block of Southern Granulite Terrane including Sri Lanka and increasing gradually to ~165-180 km beneath the northern block of Southern Granulite Terrane and the Dharwar Craton. This step-like lithosphere-asthenosphere boundary (LAB) structure indicates a normal lithospheric thickness beneath the adjoining oceans, the northern block of Southern Granulite Terrane and the Dharwar Craton. The thin lithosphere below the southern block of Southern Granulite Terrane including Sri Lanka is, however, atypical considering its age. Our results suggest that the southern Indian shield as a whole cannot be supported isostatically only by thickened crust; a thin and hot lithosphere beneath the southern block of Southern Granulite Terrane including Sri Lanka is required to explain the high topography, gravity, geoid and crustal temperatures. The widespread thermal perturbation during Pan-African (550 Ma) metamorphism and the breakup of Gondwana during late Cretaceous are proposed as twin cause mechanism for the stretching and/or convective removal of the lower part of lithospheric mantle and its replacement by hotter and lighter asthenosphere in the southern block of Southern Granulite Terrane including Sri Lanka. Unusually thinned LAB beneath the region near Bangalore apparently indicates the preserved tectonocompositional effect of late Proterozoic rifted margin of Dharwar Craton. © The Authors 2013. Published by Oxford University Press on behalf of The Royal Astronomical Society.

Mandal T.,CSIR - Central Electrochemical Research Institute | Bhowmik A.,CSIR - Central Electrochemical Research Institute | Chatterjee A.,CSIR - Central Electrochemical Research Institute | Chatterjee U.,Park Clinic | And 2 more authors.
Cellular Signalling | Year: 2014

Signal transducer and activator of transcription 3 (Stat3) is a transcription factor that is involved in cell survival and proliferation and has been found to be persistently activated in most human cancers mainly through its phosphorylation at Tyr-705. However, the role and regulation of Stat3 Ser-727 phosphorylation in cancer cells have not been clearly evaluated. In our findings, correlation studies on the expression of CK2 and Stat3 Ser-727 phosphorylation levels in human glioma patient samples as well as rat orthotopic tumor model show a degree of negative correlation. Moreover, brain tumor cell lines were treated with various pharmacological inhibitors to inactivate the CK2 pathway. Here, increased Stat3 Ser-727 phosphorylation upon CK2 inhibition was observed. Overexpression of CK2 (α, α' or β subunits) by transient transfection resulted in decreased Stat3 Ser-727 phosphorylation. Stat3 Tyr-705 residue was conversely phosphorylated in similar situations. Interestingly, we found PP2A, a protein phosphatase, to be a mediator in the negative regulation of Stat3 Ser-727 phosphorylation by CK2. In vitro assays prove that Ser-727 phosphorylation of Stat3 affects the transcriptional activity of its downstream targets like SOCS3, bcl-xl and Cyclin D1. Stable cell lines constitutively expressing Stat3 S727A mutant showed increased survival, proliferation and invasion which are characteristics of a cancer cell. Rat tumor models generated with the Stat3 S727A mutant cell line formed more aggressive tumors when compared to the Stat3 WT expressing stable cell line. Thus, in glioma, reduced Stat3 Ser-727 phosphorylation enhances tumorigenicity which may be regulated in part by CK2-PP2A pathway. © 2014 The Authors.

Reddy L.V.R.,CSIR - Central Electrochemical Research Institute | Reddy L.V.R.,Albany Molecular Research | Kumar V.,CSIR - Central Electrochemical Research Institute | Kumar V.,Indian Institute of Science | And 3 more authors.
Chemical Reviews | Year: 2013

The presence of hydroxyl functionalities and well-defined chiral centers in carbohydrates as well as their natural abundance have attracted chemists worldwide to exploit this class of molecules as precursors for synthesis of a large number of natural products and biologically active molecules during recent decades. Apart from that, various types of molecules have also been synthesized from carbohydrates with a view to using them to study biological phenomena taking place in living systems. Use of cycloadditions in organic synthesis is ubiquitous, mostly because in one step multiple stereocenters can be generated in the desired molecule with high selectivities and usually good yields. A close examination revealed that the size of the nitrogen substituent influenced the rotational preference with the larger substituent providing higher diastereomeric ratio.

Kumar R.,International Center for Material Science | Jayaramulu K.,International Center for Material Science | Maji T.K.,International Center for Material Science | Rao C.N.R.,International Center for Material Science | Rao C.N.R.,CSIR - Central Electrochemical Research Institute
Chemical Communications | Year: 2013

Hybrid nanocomposites of graphene oxide (GO) with ZIF-8 exhibit tunable nanoscale morphology and porosity, both determined by the GO content, coordination modulation being responsible for such properties. These materials also give rise to high CO2 storage capability and can be used as precursors to prepare GO@ZnS nanocomposites. This journal is © The Royal Society of Chemistry.

Mandal P.K.,CSIR - Central Electrochemical Research Institute | Dhara D.,Bose Institute of India | Misra A.K.,Bose Institute of India
Beilstein Journal of Organic Chemistry | Year: 2014

A straightforward convergent synthesis has been carried out for the tetrasaccharide repeating unit of the O-specific cell wall lipopolysaccharide of the strain Sp7 of Azospirillum brasilense. The target tetrasaccharide has been synthesized from suitably protected monosaccharide intermediates in 42% overall yield in seven steps by using a [2 + 2] block glycosylation approach. © 2014 Mandal et al; licensee Beilstein-Institut.

Lakshminarasimhan N.,Pohang University of Science and Technology | Lakshminarasimhan N.,CSIR - Central Electrochemical Research Institute | Bokare A.D.,Pohang University of Science and Technology | Choi W.,Pohang University of Science and Technology
Journal of Physical Chemistry C | Year: 2012

Two mesoporous TiO 2 samples (M1-TiO 2 and M2-TiO 2) with different morphologies were synthesized, and the photocatalytic and photoelectrochemical properties of both TiO 2 and their photoplatinized counterparts (0.05, 0.1, and 1.0 wt % of Pt) were systematically investigated. Electron microscopic analysis showed that M1-TiO 2 consists of densely packed nanoparticles forming spherical secondary particles (0.5 to 1.0 μm), whereas M2-TiO 2 is made up of loosely agglomerated nanoparticles. Subsequently, this morphological difference led to the formation of different Pt clusters (photodeposited on them): large Pt nanoparticles on M1-TiO 2 versus well-dispersed smaller Pt nanoparticles on M2-TiO 2. The photocatalytic activities of platinized M1-TiO 2 and M2-TiO 2 were investigated for H2 production and 4-chlorophenol degradation. Whereas M1-TiO 2 exhibited the highest photoactivity with 0.1 wt % Pt loading, the activity of M2-TiO 2 increased with increasing Pt loading (up to 1.0 wt %). The critical role of surface Pt morphology on the photocatalytic behavior of M1-TiO 2 and M2-TiO 2 was investigated using electrochemical impedance spectroscopy and photocurrent measurements. In the case of M1-TiO 2, an increase in Pt cluster size enhanced the charge-transfer resistance and reduced the interfacial electron transfer efficiency, whereas the same loading of Pt on M2-TiO 2 effectively enhanced the interfacial charge transfer. This dissimilar interfacial charge-transfer kinetics for M1-TiO 2 and M2-TiO 2 indicates that the TiO 2 microstructure controls the photodeposited Pt morphology, which subsequently affects the photocatalytic activity. This study reveals that the agglomerated state of TiO 2 nanoparticles can be an important parameter in determining the photocatalytic activity in both the suspension and film states. © 2012 American Chemical Society.

Majumdar D.,Bose Institute of India | Singha A.,Bose Institute of India | Mondal P.K.,Saha Institute of Nuclear Physics | Kundu S.,CSIR - Central Electrochemical Research Institute
ACS Applied Materials and Interfaces | Year: 2013

Stable metal nanoclusters (NCs) with uniform interior nanogaps reproducibly offer a highly robust substrate for surface-enhanced Raman scattering (SERS) because of the presence of abundant hot spots on their surface. The synthesis of such an SERS substrate by a simple route is a challenging task. Here, we have synthesized a highly stable wirelike cluster of silver nanoparticles (Ag-NPs) with an interparticle gap of ∼1.7 ± 0.2 nm using deoxyribonucleic acid (DNA) as the template by exploiting an easy and inexpensive chemical route. The red shift in the surface plasmon resonance (SPR) band of Ag-NCs compared to SPR of a single Ag-NP confirms the strong interplasmonic interaction. Methylene Blue (MB) is used as a representative Raman probe to study the SERS effect of the NCs. The SERS measurements reveal that uniform, reproducible, and strong Raman signals were observed up to the single-molecule level. The intensity of the Raman signal is not highly dependent on the polarization of the excitation laser. The DNA-based Ag-NCs as a substrate show better isotropic behavior for their SERS intensity compared to the dimer, as confirmed from both the experimental and theoretical simulation results. We believe that in the future the DNA-based Ag-NCs might be useful as a potential SERS substrate for ultrasensitive trace detection, biomolecular assays, NP-based photothermal therapeutics, and a few other technologically important fields. © 2013 American Chemical Society.

Beaume N.,CSIR - Central Electrochemical Research Institute | Pathak R.,CSIR - Central Electrochemical Research Institute | Yadav V.K.,CSIR - Central Electrochemical Research Institute | Kota S.,Bhabha Atomic Research Center | And 3 more authors.
Nucleic Acids Research | Year: 2013

A remarkable number of guanine-rich sequences with potential to adopt non-canonical secondary structures called G-quadruplexes (or G4 DNA) are found within gene promoters. Despite growing interest, regulatory role of quadruplex DNA motifs in intrinsic cellular function remains poorly understood. Herein, we asked whether occurrence of potential G4 (PG4) DNA in promoters is associated with specific function(s) in bacteria. Using a normalized promoter-PG4-content (PG4P) index we analysed >60 000 promoters in 19 well-annotated species for (a) function class(es) and (b) gene(s) with enriched PG4 P. Unexpectedly, PG4-associated functional classes were organism specific, suggesting that PG4 motifs may impart specific function to organisms. As a case study, we analysed radioresistance. Interestingly, unsupervised clustering using PG4P of 21 genes, crucial for radioresistance, grouped three radioresistant microorganisms including Deinococcus radiodurans. Based on these predictions we tested and found that in presence of nanomolar amounts of the intracellular quadruplex-binding ligand N-methyl mesoporphyrin (NMM), radioresistance of D. radiodurans was attenuated by ∼60%. In addition, important components of the RecF recombinational repair pathway recA, recF, recO, recR and recQ genes were found to harbour promoter-PG4 motifs and were also down-regulated in presence of NMM. Together these results provide first evidence that radioresistance may involve G4 DNA-mediated regulation and support the rationale that promoter-PG4s influence selective functions. © 2012 The Author(s). Published by Oxford University Press.

Chakraborty A.,CSIR - Central Electrochemical Research Institute | Mandloi S.,CSIR - Central Electrochemical Research Institute | Lanczycki C.J.,U.S. National Center for Biotechnology Information | Panchenko A.R.,U.S. National Center for Biotechnology Information | Chakrabarti S.,CSIR - Central Electrochemical Research Institute
Nucleic Acids Research | Year: 2012

Sites that show specific conservation patterns within subsets of proteins in a protein family are likely to be involved in the development of functional specificity. These sites, generally termed specificity determining sites (SDS), might play a crucial role in binding to a specific substrate or proteins. Identification of SDS through experimental techniques is a slow, difficult and tedious job. Hence, it is very important to develop efficient computational methods that can more expediently identify SDS. Herein, we present Specificity prediction using amino acids' Properties, Entropy and Evolution Rate (SPEER)-SERVER, a web server that predicts SDS by analyzing quantitative measures of the conservation patterns of protein sites based on their physico-chemical properties and the heterogeneity of evolutionary changes between and within the protein subfamilies. This web server provides an improved representation of results, adds useful input and output options and integrates a wide range of analysis and data visualization tools when compared with the original standalone version of the SPEER algorithm. Extensive benchmarking finds that SPEER-SERVER exhibits sensitivity and precision performance that, on average, meets or exceeds that of other currently available methods. SPEER-SERVER is available at http://www.hpppi.iicb.res.in/ss/. © 2012 The Author(s).

Sengupta D.,North Bengal University | Saha J.,CSIR - Central Electrochemical Research Institute | De G.,CSIR - Central Electrochemical Research Institute | Basu B.,North Bengal University
Journal of Materials Chemistry A | Year: 2014

Cationic and macroporous amberlite resins with formate (HCOO-) as the counter anion (ARF) have been used to prepare a new class of heterogeneous Pd/Cu bimetallic composite nanoparticles (NPs) (Pd/Cu-ARF). The physicochemical characteristics of Pd/Cu-ARF were examined with the help of FTIR spectroscopy, X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and atomic absorption spectroscopy (AAS). XRD and TEM showed the existence of composite NPs made of metallic Pd, PdO and CuO. The TEM analysis revealed fairly uniform distributions of composite NPs of average size ∼4.9 nm. The as-synthesized nanocomposite material (Pd/Cu-ARF) exhibited high catalytic activity in the Sonogashira cross-coupling reaction between aryl iodide and terminal alkynes. Heterogeneity of the catalytic activity was evidenced from different tests (hot-filtration and catalyst-poisoning experiments) and the recycling ability of the catalyst was examined for five consecutive runs without any significant loss of activity. © 2014 The Royal Society of Chemistry.

Mandotra S.K.,CSIR - Central Electrochemical Research Institute | Mandotra S.K.,Sam Higginbottom Institute of Agriculture, Technology and Sciences | Kumar P.,CSIR - Central Electrochemical Research Institute | Suseela M.R.,CSIR - Central Electrochemical Research Institute | Ramteke P.W.,Sam Higginbottom Institute of Agriculture, Technology and Sciences
Bioresource Technology | Year: 2014

Present investigation studied the potential of fresh water green microalga Scenedesmus abundans as a feedstock for biodiesel production. To study the biomass and lipid yield, the culture was grown in BBM, Modified CHU-13 and BG-11 medium. Among the tested nitrogen concentration using Modified CHU-13 medium, the highest biomass and lipid yield of 1.113±0.05g/L and 489±23mg/L respectively was found in the culture medium with 0.32g/L of nitrogen (KNO3). Different lipid extraction as well as transesterification methods were also tested. Fatty acid profile of alga grown in large scale indigenous made photobioreactor has shown abundance of fatty acids with carbon chain length of C16 and C18. Various biodiesel properties such as cetane number, iodine value and saponification value were found to be in accordance with Brazilian National Petroleum Agency (ANP255) and European biodiesel standard EN14214 which makes S. abundans as a potential feedstock for biodiesel production. © 2014 Elsevier Ltd.

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.

Yasumatsu H.,Toyota Technological Institute | Murugan P.,CSIR - Central Electrochemical Research Institute | Kawazoe Y.,Tohoku University
Physica Status Solidi (B) Basic Research | Year: 2012

We studied geometric and electronic structures of a platinum cluster disk consisting 30 Pt atoms on the Si(111)-7×7 surface by STM experiments (see left panel) and first principles calculations. It was found that the high stability of the cluster disk on the Si surface originates from the platinum-silicide bonds as strong as ∼45eV per cluster, which are formed by electron transfer from the 5d orbital of the Pt atoms to the 3s and 3p ones of the Si atoms. This finding gives an essential interpretation to the experimental discovery that valence electrons in an occupied molecular orbital of the Pt 30/Si system are distributed in a wider region than the locations of the Pt atoms. It appeared that electron accumulation at the interface between the cluster and the substrate induces two-dimensional charge polarization in a nanospace as shown in right panel due to a combination of a metallic nature of the cluster disk and a highly resistive nature of the Si surface. STM image (left) of a monatomic-layered platinum cluster disk, Pt 30, constructed on the Si(111) surface. Schematic image (right) of two-dimensional charge polarization; the Pt-5d electrons are distributed out of the cluster, so that the centre and the periphery of the cluster are charged positively and negatively, respectively. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Mahato S.K.,University of Johannesburg | Ul Islam R.,University of Johannesburg | Acharya C.,CSIR - Central Electrochemical Research Institute | Witcomb M.J.,University of Witwatersrand | Mallick K.,University of Johannesburg
ChemCatChem | Year: 2014

Polypyrrole stabilised palladium nanoparticles show good catalytic efficiency for the chemoselective transfer hydrogenation of α,β- unsaturated carbonyl compounds. The catalyst is very specific and selectively hydrogenates the olefins or acetylenes only, without affecting the carbonyl moiety, with an excellent yield of products for a wide range of substrates. Podium position for palladium: A palladium-polypyrrole composite is synthesized for the chemoselective transfer hydrogenation of α,β-unsaturated carbonyl compounds by using an in situ polymerisation and composite formation method. No semi-hydrogenated product was observed with alkyne systems and hydrodehalogenation of the haloarene segment of the substrate was not encountered in reactions with this catalyst. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Mitra A.,University of Calcutta | Ray A.,University of Calcutta | Datta R.,University of Calcutta | Sengupta S.,CSIR - Central Electrochemical Research Institute | Sarkar S.,University of Calcutta
Journal of Cellular Physiology | Year: 2014

Myocardial infarction (MI) is defined as cardiac cell death due to prolonged ischemia. Although necrotic cell death was considered to be solely responsible for myocyte death during MI, it was recently revealed that apoptosis also plays its part in this death process. Our laboratory has recently shown that endoplasmic reticulum (ER) stress-induced apoptosis is the predominant route for apoptosis during MI and the conventional mitochondrial pathway is bypassed by activation of a small heat shock protein α-crystallin B (CRYAB). Since CRYAB is a direct target of P38 mitogen-activated protein kinase (MAPK) cascade, we were prompted to check the role of P38 MAPK in 20-week-old male Wister rats immediately after infarct formation. Interestingly, parallel activation of mitochondrial apoptotic pathway with an increase in ER stress-induced apoptotic load was observed along with decreased activation of CRYAB and Nrf2 (a pro-survival protein activated in response to ER stress) in MI rats treated with SB203580, a specific inhibitor of P38α and P38β compared to the MI alone. As a cumulative effect, this inhibitor treatment also resulted in significant increase in the levels of caspase3 activity and TUNEL positivity, the end point apoptotic markers. Furthermore, SB203580-treated hypoxic adult cardiomyocytes showed formation of desmin aggregates which were previously associated with impaired cardiac function. Thus, this study shows for the first time the precise mechanism by which P38 MAPK plays a pro-survival role and confers protection of cardiomyocytes, during infarct formation. © 2014 Wiley Periodicals, Inc.

Vasudevan S.,CSIR - Central Electrochemical Research Institute | Oturan M.A.,University Paris Est Creteil
Environmental Chemistry Letters | Year: 2014

This article reviews both the pollution by the electrochemical industry and the use of electrochemistry to clean water. Main pollutants include Pd, Cd, Ni, Hg and other metals and cyanide as well as organic pollutants. The cause for water pollution by electrochemistry is due to the effluents from different electrochemical industries such as mercury from chlor-alkali industry; lead, cadmium and mercury from battery industry; heavy metals and organic contaminants from electroplating wastes; contaminants from corrosion processes; and persistent organic pollutants from the synthesis and use of pesticides, dyes and pharmaceuticals. Most pollutants can be successfully eliminated or converted to non-toxic materials by methods based on the electrochemical principles. Electrochemical depolluting methods are mainly electrodialysis, electrocoagulation, electroflotation, anodic processes, cathodic processes and electrochemical advanced oxidation processes. © 2013 Springer-Verlag Berlin Heidelberg.

Sekhar B.C.,CSIR - Central Electrochemical Research Institute | Babu G.,Wayne State University | Kalaiselvi N.,CSIR - Central Electrochemical Research Institute
RSC Advances | Year: 2015

Mn2O3 microcubes, symmetrically formed out of the systematic stacking of nanoflakes, built with nanoparticles in the 30-50 nm range have been obtained from a simple co-precipitation method. Excluding the requirement of a structure directing additive, the currently adopted synthesis protocol signifies the vital role of the rate of (NH4)HCO3 precursor addition, which has been optimized as 2 h for 300 mL to obtain uniformly stacked nanoflakes of Mn2O3 to form microcubes with desired morphological features. Cooked rice carbon (CRC), obtained from a filth-to-wealth conversion, has been used as conducting additive and an optimum concentration of 20 wt% CRC was found to be sufficient to form Mn2O3/CRC with improved lithium intercalation/de-intercalation behavior. The twin advantages, namely exploitation of a cheap and eco-benign composite additive obtained from a common domestic waste in the form of CRC and the optimized speed of addition of (NH4)HCO3 to form Mn2O3 microcubes obtained from nanoflakes offer advantages in terms of enhanced electronic conductivity and provision to buffer the volume changes of Mn2O3 anode, respectively. The optimized Mn2O3/CRC-20 composite anode exhibits an appreciable capacity of 830 mA h g-1 after formation cycle and an acceptable capacity of 490 mA h g-1 after completing 100 cycles, under the influence of 50 mA g-1 current density. Further, Mn2O3/CRC-20 anode exhibits a reasonable capacity of 450 mA h g-1 at 100 mA g-1 up to 50 cycles and qualifies itself as a potential anode material. © The Royal Society of Chemistry 2015.

Srinivasa Gowd S.,CSIR - Central Electrochemical Research Institute | Srinivasa Gowd S.,Yogi Vemana University | Ramakrishna Reddy M.,Yogi Vemana University | Govil P.K.,CSIR - Central Electrochemical Research Institute
Journal of Hazardous Materials | Year: 2010

Environmental geochemical studies were carried out in and around Jajmau (Kanpur) and Unnao industrial areas (80°15′-80°34′E longitude and 26°24′-26°35′N latitude), of Uttar Pradesh to find out the extent of chemical pollution in soil due to industrial waste. Jajmau and Unnao are prominent centers for leather processing clusters of tannery industries (about 450) along the banks of river Ganga, besides other industries. Geologically the study area is beset with alluvium of Quaternary age consisting of older alluvium of middle to upper Pleistocene and newer alluvium of Holocene. The climate of the study area is semi-arid type. Fifty-three soil samples were collected from Jajmau and Unnao industrial areas from top 15 cm layer of the soil and were analyzed for heavy metals by using Philips MagiX PRO-PW 2440 X-ray fluorescence spectrometer. The data reveals that the soil in the area is significantly contaminated with heavy metals such as chromium varies from 161.8 to 6227.8 mg/kg (average of 2652.3 mg/kg), Ba varies from 44.1 to 780.9 mg/kg (average of 295.7 mg/kg), Cu varies from 1.7 to 126.1 mg/kg (average of 42.9 mg/kg), Pb varies from 10.1 to 67.8 mg/kg (average of 38.3 mg/kg), Sr varies from 46.6 to 150.6 mg/kg (average of 105.3 mg/kg), V varies from 1.3 to 208.6 mg/kg (average of 54.4 mg/kg) and Zn varies from 43.5 to 687.6 mg/kg (average of 159.9 mg/kg). Soil contamination was assessed on the basis of geoaccumulation index, enrichment factor (EF), contamination factor and degree of contamination. Indiscriminate dumping of hazardous waste in the study area could be the main cause of the soil contamination, spreading by rainwater and wind. Distribution and correlation of heavy metals in soil along with possible remedial measures are discussed. © 2009 Elsevier B.V. All rights reserved.

Maiti S.,Indian School of Mines | Tiwari R.K.,CSIR - Central Electrochemical Research Institute
Environmental Earth Sciences | Year: 2014

Predictive modeling of hydrological time series is essential for groundwater resource development and management. Here, we examined the comparative merits and demerits of three modern soft computing techniques, namely, artificial neural networks (ANN) optimized by scaled conjugate gradient (SCG) (ANN.SCG), Bayesian neural networks (BNN) optimized by SCG (BNN.SCG) with evidence approximation and adaptive neuro-fuzzy inference system (ANFIS) in the predictive modeling of groundwater level fluctuations. As a first step of our analysis, a sensitivity analysis was carried out using automatic relevance determination scheme to examine the relative influence of each of the hydro-meteorological attributes on groundwater level fluctuations. Secondly, the result of stability analysis was studied by perturbing the underlying data sets with different levels of correlated red noise. Finally, guided by the ensuing theoretical experiments, the above techniques were applied to model the groundwater level fluctuation time series of six wells from a hard rock area of Dindigul in Southern India. We used four standard quantitative statistical measures to compare the robustness of the different models. These measures are (1) root mean square error, (2) reduction of error, (3) index of agreement (IA), and (4) Pearson's correlation coefficient (R). Based on the above analyses, it is found that the ANFIS model performed better in modeling noise-free data than the BNN.SCG and ANN.SCG models. However, modeling of hydrological time series correlated with significant amount of red noise, the BNN.SCG models performed better than both the ANFIS and ANN.SCG models. Hence, appropriate care should be taken for selecting suitable methodology for modeling the complex and noisy hydrological time series. These results may be used to constrain the model of groundwater level fluctuations, which would in turn, facilitate the development and implementation of more effective sustainable groundwater management and planning strategies in semi-arid hard rock area of Dindigul, Southern India and alike. © 2013 Springer-Verlag Berlin Heidelberg.

Tiwari B.M.,CSIR - Central Electrochemical Research Institute | Kannan N.,CSIR - Central Electrochemical Research Institute | Vemu L.,Nizam's Institute of Medical Sciences | Raghunand T.R.,CSIR - Central Electrochemical Research Institute
PLoS ONE | Year: 2012

The unique PE/PPE multigene family of proteins occupies almost 10% of the coding sequence of Mycobacterium tuberculosis (M.tb), the causative agent of human tuberculosis. Although some members of this family have been shown to be involved in pathways essential to M.tb pathogenesis, their precise physiological functions remain largely undefined. Here, we investigate the roles of the conserved members of the 'PE only' subfamily Rv0285 (PE5) and Rv1386 (PE15) in mediating host-pathogen interactions. Recombinant Mycobacterium smegmatis strains expressing PE5 and PE15 showed enhanced survival vs controls in J774.1 and THP-1 macrophages - this increase in viable counts was correlated with a reduction in transcript levels of inducible nitric oxide synthase. An up-regulation of anti- and down-regulation of pro-inflammatory cytokine levels was also observed in infected macrophages implying an immuno-modulatory function for these proteins. Induction of IL-10 production upon infection of THP-1 macrophages was associated with increased phosphorylation of the MAP Kinases p38 and ERK1/2, which was abolished in the presence of the pharmacological inhibitors SB203580 and PD98059. The PE5-PPE4 and PE15-PPE20 gene pairs were observed to be co-operonic in M.tb, hinting at an additional level of complexity in the functioning of these proteins. We conclude that M.tb exploits the PE proteins to evade the host immune response by altering the Th1 and Th2 type balance thereby favouring in vivo bacillary survival. © 2012 Tiwari et al.

Singh A.G.,Tribhuvan University | Kumar A.,CSIR - Central Electrochemical Research Institute | Tewari D.D.,Maharani Lal Kunwari Post Graduate College
Journal of Ethnobiology and Ethnomedicine | Year: 2012

Background: Nepal Himalayas have been known as a rich source for valuable medicinal plants since Vedic periods. Present work is the documentation of indigenous knowledge on plant utilization as natural remedy by the inhabitants of terai forest in Western Nepal.Methods: Study was conducted during 2010-2011 following standard ethnobotanical methods. Data about medicinal uses of plants were collected by questionnaire, personal interview and group discussion with pre identified informants. Voucher specimens were collected with the help of informants, processed into herbarium following standard methods, identified with the help of pertinent floras and taxonomic experts, and submitted in Department of Botany, Butwal Multiple Campus, Tribhuvan University, Nepal for future references.Results: During the present study 66 medicinal plant species belonging to 37 families and 60 genera has been documented. These plants were used to treat various diseases and ailments grouped under 11 disease categories, with the highest number of species (41) being used for gastro-intestinal disorders, followed by dermatological disorders (34). In the study area the informants' consensus about usages of medicinal plants ranges from 0.93 to 0.97 with an average value of 0.94. Herbs (53%) were the primary source of medicine, followed by trees (23%). Curcuma longa (84%) and Azadirachta indica (76%) are the most frequently and popularly used medicinal plant species in the study area. Acacia catechu, Bacopa monnieri, Bombax ceiba, Drymaria diandra, Rauvolfia serpentina, and Tribulus terrestris are threatened species which needs to be conserved for future use.Conclusions: The high degree of consensus among the informants suggests that current use and knowledge are still strong, and thus the preservation of today's knowledge shows good foresight in acting before much has been lost. The connections between plant use and conservation are also important ones, especially as the authors note that neither the local inhabitants nor the government is addressing the potential loss of valuable species in this region. © 2012 Singh et al.; licensee BioMed Central Ltd.

Gupta P.,University of Calcutta | Das P.K.,CSIR - Central Electrochemical Research Institute | Ukil A.,University of Calcutta
Antimicrobial Agents and Chemotherapy | Year: 2015

18β-Glycyrrhetinic acid (GRA), a natural immunomodulator, greatly reduced the parasite load in experimental visceral leishmaniasis through nitric oxide (NO) upregulation, proinflammatory cytokine expression, and NF-κB activation. For the GRA-mediated effect, the primary kinase responsible was found to be p38, and analysis of phosphorylation kinetics as well as studies with dominant-negative (DN) constructs revealed mitogen-activated protein kinase kinase 3 (MKK3) and MKK6 as the immediate upstream regulators of p38. However, detection of remnant p38 kinase activity in the presence of both DN MKK3 and MKK6 suggested alternative pathways of p38 activation. That residual p38 activity was attributed to an autophosphorylation event ensured by the transforming growth factor β-activated kinase 1 (TAK1)-binding protein 1 (TAB1)-p38 interaction and was completely abolished upon pretreatment with SB203580 in DN MKK3/6 double-transfected macrophage cells. Further upstream signaling evaluation by way of phosphorylation kinetics and transfection studies with DN constructs identified TAK1, myeloid differentiation factor 88 (MyD88), interleukin 1 receptor (IL-1R)-activated kinase 1 (IRAK1), and tumor necrosis factor (TNF) receptor-associated factor 6 (TRAF6) as important contributors to GRA-mediated macrophage activation. Finally, gene knockdown studies revealed Toll-like receptor 2 (TLR2) and TLR4 as the membrane receptors associated with GRA-mediated antileishmanial activity. Together, the results of this study brought mechanistic insight into the antileishmanial activity of GRA, which is dependent on the TLR2/4-MyD88 signaling axis, leading to MKK3/6-mediated canonical and TAB1-mediated noncanonical p38 activation. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Mitra A.,University of Calcutta | Basak T.,CSIR - Central Electrochemical Research Institute | Datta K.,University of Calcutta | Naskar S.,University of Calcutta | And 2 more authors.
Cell Death and Disease | Year: 2013

Cardiac hypertrophy and myocardial infarction (MI) are two major causes of heart failure with different etiologies. However, the molecular mechanisms associated with these two diseases are not yet fully understood. So, this study was designed to decipher the process of cardiomyocyte apoptosis during cardiac hypertrophy and MI in vivo. Our study revealed that mitochondrial outer membrane channel protein voltage-dependent anion channel-1 (VDAC1) was upregulated exclusively during cardiac hypertrophy, whereas 78 kDa glucose-regulated protein (GRP78) was exclusively upregulated during MI, which is an important upstream regulator of the endoplasmic reticulum (ER) stress pathway. Further downstream analysis revealed that mitochondrial pathway of apoptosis is instrumental in case of hypertrophy, whereas ER stress-induced apoptosis is predominant during MI, which was confirmed by treatment with either siRNA against VDAC1 or ER stress inhibitor tauroursodeoxycholic acid (TUDCA). Very interestingly, our data also showed that the expression and interaction of small heat-shock protein a-crystallin B (CRYAB) with VDAC1 was much more pronounced during MI compared with either hypertrophy or control. The study demonstrated for the first time that two different organelles-mitochondria and ER have predominant roles in mediating cardiomyocyte death signaling during hypertrophy and MI, respectively, and activation of CRYAB acts as a molecular switch in bypassing mitochondrial pathway of apoptosis during MI. © 2013 Macmillan Publishers Limited All rights reserved.

Santosh M.,China University of Geosciences | Yang Q.-Y.,China University of Geosciences | Shaji E.,Kerala University | Tsunogae T.,University of Tsukuba | And 2 more authors.
Gondwana Research | Year: 2015

Sandwiched between the Dharwar Craton in the north and the Neoarchean-Proterozoic crustal blocks to the south, the Coorg Block in southern India is composed dominantly of a suite of arc magmatic rocks including charnockites, TTG (tonalite-trondhjemite-granodiorite)-related granitoid suite and felsic volcanic tuffs together with minor accreted oceanic remnants along the periphery of the block. Coeval mafic and felsic magmatism with magma mixing and mingling in an arc setting is well represented in the block. Here we present the petrology, geochemistry, zircon U-Pb geochronology and Lu-Hf isotopes of all the major lithologies from this block. Computation of metamorphic P-T conditions from mineral chemical data shows consistent granulite-facies P-T conditions of 820-870°C and up to 6kbar. Our geochemical data from major, trace and REE on representative samples of the dominant rock types from the Coorg Block corroborate an arc-related signature, with magma generation in a convergent margin setting. The zircon data yield weighted mean 207Pb/206Pb ages of 3153.4±9 to 3184.0±5.5Ma for syenogranites, 3170.3±6.8Ma for biotite granite, 3275±5.1Ma for trondhjemite, 3133±12 to 3163.8 ±6.9Ma for charnockites, 3156±10 to 3158.3±8.2 for mafic enclaves, 3161±16Ma for diorite and 3173±16Ma for felsic volcanic tuff. An upper intercept age of 3363±59Ma and a lower intercept age of 2896±130Ma on zircons from a charnockite, as well as an evaluation of the Th/U values of the zircon domains against respective 207Pb/206Pb ages suggest that the Mesoarchean magma emplacement which probably ranged from >3.3 to 3.1Ga was immediately followed by metamorphism at ca. 3.0 to 2.9Ga. The ages of magmatic zircons from the charnockites and their mafic granulite enclaves, as well as those from the volcanic tuff and biotite granite, are all remarkably consistent and concordant marking ca. 3.1Ga as the peak of subduction-related crust building in this block, within the tectonic milieu of an active convergent margin. The majority of zircons from the Coorg rocks show Hf isotope features typical of crystallization from magmas derived from juvenile sources. Their Hf crustal model ages suggest that the crust building might have also involved partial recycling of basement rocks as old as ca. 3.8Ga. The crustal blocks in the Southern Granulite Terrane in India preserve strong imprints of major tectonothermal events at 2.5Ga, 2.0Ga, 0.8Ga and 0.55Ga associated with various subduction-accretion-collision or rifting events. However, the Coorg Block is exceptional with our data suggesting that none of the above events affected this block. Importantly, there is also no record in the Coorg Block for the 2.5Ga pervasive regional metamorphism that affected all the other blocks in this region. The geochronological data raise the intriguing possibility that this block is an exotic entity within the dominantly Neoarchean collage in the northern domain of the Southern Granulite Terrane of India. The Mesoarchean arc-related rocks in the Coorg Block suggest that the magma factories and their tectonic architecture in the Early Earth were not markedly different from those associated with the modern-style plate tectonics. © 2013 International Association for Gondwana Research.

Ojha M.,CSIR - Central Electrochemical Research Institute | Maiti S.,Indian Institute of Geomagnetism DST
Deep-Sea Research Part II: Topical Studies in Oceanography | Year: 2013

A novel approach based on the concept of Bayesian neural network (BNN) has been implemented for classifying sediment boundaries using downhole log data obtained during Integrated Ocean Drilling Program (IODP) Expedition 323 in the Bering Sea slope region. The Bayesian framework in conjunction with Markov Chain Monte Carlo (MCMC)/hybrid Monte Carlo (HMC) learning paradigm has been applied to constrain the lithology boundaries using density, density porosity, gamma ray, sonic P-wave velocity and electrical resistivity at the Hole U1344A. We have demonstrated the effectiveness of our supervised classification methodology by comparing our findings with a conventional neural network and a Bayesian neural network optimized by scaled conjugate gradient method (SCG), and tested the robustness of the algorithm in the presence of red noise in the data. The Bayesian results based on the HMC algorithm (BNN.HMC) resolve detailed finer structures at certain depths in addition to main lithology such as silty clay, diatom clayey silt and sandy silt. Our method also recovers the lithology information from a depth ranging between 615 and 655 m Wireline log Matched depth below Sea Floor of no core recovery zone. Our analyses demonstrate that the BNN based approach renders robust means for the classification of complex lithology successions at the Hole U1344A, which could be very useful for other studies and understanding the oceanic crustal inhomogeneity and structural discontinuities. © 2013 Elsevier Ltd. All rights reserved.

Gopal P.K.,Gurudas College | Paul M.,CSIR - Central Electrochemical Research Institute | Paul S.,Gurudas College
Asian Pacific Journal of Cancer Prevention | Year: 2014

Background: Curcumin has has been reported to exert anti-inflammatory, anti-oxidation and anti-angiogenic activity in various types of cancer. It has also been shown to induce apoptosis in leukemia cells. We aimed to unravel the role of the redox pathway in Curcumin mediated apoptosis with a panel of human leukemic cells. Materials and Methods: In this study in vitro cytotoxicity of Curcumin was measured by MTT assay and apoptotic effects were assessed by annexin V/PI, DAPI staining, cell cycle analysis, measurement of caspase activity and PARP cleavage. Effects of Curcumin on intracellular redox balance were assessed using fluorescent probes like H2DCFDA, JC1 and an ApoGSH Glutathione Detection Kit respectively. Results: Curcumin showed differential anti-proliferative and apoptotic effects on different human leukemic cell lines in contrast to minimal effects on normal cells. Curcumin induced apoptosis was associated with the generation of intracellular ROS, loss of mitochondrial membrane potential, intracellular GSH depletion, caspase activation. Conclusions: As Curcumin induces programmed cell death specifically in leukemic cells it holds a great promise as a future therapeutic agent in the treatment of leukemia.

Santosh M.,China University of Geosciences | Shaji E.,Kerala University | Tsunogae T.,University of Tsukuba | Ram Mohan M.,CSIR - Central Electrochemical Research Institute | And 2 more authors.
Precambrian Research | Year: 2013

The southern margin of the Dharwar Craton in Peninsular India preserves the records of an active convergent margin during the Neoarchean. Here we report the discovery of a relatively well-preserved suprasubduction zone ophiolite suite from the Agali hill in Attappadi, along the western extension of the Bhavani Shear Zone. In the Agali hill, from base to top, the rock sequence includes altered ultramafics with vestiges of dunite, thin layer of cumulate pyroxenite, a thick unit of metagabbro with the upper part grading into anorthositic gabbro and carrying thin layers of hornblendite, capped by metavolcanics (amphibolites) carrying veins and pools of trondhjemite. Fragments of metabasite (dolerite) dykes occur within the gabbroic horizon. Elongate bands of metamorphosed banded iron formation in association with amphibolite occur proximally. The lithological distribution in the area represents a typical 'Ocean Plate Stratigraphy' sequence with arc and exhumed sub-arc mantle material toward the north-west, followed by accreted remnants of suprasubduction zone ophiolites, large tracts of TTG gneisses, and amphibolites in association with BIF bands. The central domain is occupied by a granite batholith. Toward the south-east, the dominant lithology grades to a continental shelf sequence represented by metamorphosed psammitic and pelitic rocks (trench) and metacarbonates. The common occurrence of magnesite in association with ultramafic units in the area suggests CO2-induced metasomatism of peridotites in the mantle wedge through fluids released within the subduction zone. We present major, trace and REE data on the Agali Ophiolite Complex which clearly suggest magma derivation in a suprasubduction setting in the absence of any significant crustal contamination. The internal structure as imaged from CL images of zircons separated from metagabbro, trondhjemite and metagranite show features typical of magmatic crystallization, with the grains mantled by bright structureless thin rims developed during a dominantly dry metamorphic event. The U-Pb concordia ages of 2547 ± 17. Ma (MSWD 0.84) and 2547 ± 7.4. Ma (MSWD 2.4) obtained from zircons in the metagabbro and trondhjemite are indistinguishable; the zircons in the metagranite also show comparable magmatic age of 2532 ± 8.6. Ma (MSWD 2.5) with metamorphic overgrowth at ca. 2470. Ma. These ages correlate well with similar age data reported recently from suprasubduction zone and arc-related rocks elsewhere along the southern margin of the Dharwar Craton. We propose a tectonic model that envisages accretion of oceanic arcs and micro-continents onto the margin of the Dharwar Craton during Neoarchean, marking an important event of continental growth, and broadly coinciding with the global crustal growth event at this time. © 2013 Elsevier B.V.

Banerjee P.,CSIR - Central Electrochemical Research Institute | Singh V.S.,CSIR - Central Electrochemical Research Institute | Chatttopadhyay K.,Satyam Computer Services Ltd. | Chandra P.C.,Central Ground Water Board | Singh B.,Technology Bhavan
Journal of Hydrology | Year: 2011

The paper evaluates the prospect of artificial neural network (ANN) simulation over mathematical modeling in estimating safe pumping rate to maintain groundwater salinity in island aquifers. Feed-forward ANN model with quick propagation (QP) as training algorithm has been used to forecast the salinity under varied pumping rates. The accuracy, generalization ability and reliability of the model are verified by real-time field data. The model is trained with 2 years of real-time field data and prediction on water quality with varying pumping rate is made for a span of 5 years. The same is then compared with both real-time field data and the prediction based on SUTRA (Saturated-Unsaturated Transport) computations. The proposed ANN model has surfaced as a simpler and more accurate alternative to the numerical method techniques. The ANN methodology using minimal lag and number of hidden nodes, along with the optimal number of spatial and temporal variables consistently produced the best performing network based simulation models. The prediction accuracy of the ANN model has been extended for another 5 years to further define the limit of pumping at a permissible level of groundwater salinity. © 2010 Elsevier B.V.

Tiwari R.K.,CSIR - Central Electrochemical Research Institute | Maiti S.,Indian Institute of Geomagnetism DST
Nonlinear Processes in Geophysics | Year: 2011

A novel technique based on the Bayesian neural network (BNN) theory is developed and employed to model the temperature variation record from the Western Himalayas. In order to estimate an a posteriori probability function, the BNN is trained with the Hybrid Monte Carlo (HMC)/Markov Chain Monte Carlo (MCMC) simulations algorithm. The efficacy of the new algorithm is tested on the well known chaotic, first order autoregressive (AR) and random models and then applied to model the temperature variation record decoded from the tree-ring widths of the Western Himalayas for the period spanning over 1226-2000 AD. For modeling the actual tree-ring temperature data, optimum network parameters are chosen appropriately and then cross-validation test is performed to ensure the generalization skill of the network on the new data set. Finally, prediction result based on the BNN model is compared with the conventional artificial neural network (ANN) and the AR linear models results. The comparative results show that the BNN based analysis makes better prediction than the ANN and the AR models. The new BNN modeling approach provides a viable tool for climate studies and could also be exploited for modeling other kinds of environmental data. © Author(s) 2011.

Hokey D.A.,Aeras Global TB Vaccine Foundation | Misra A.,CSIR - Central Electrochemical Research Institute
Tuberculosis | Year: 2011

Pulmonary delivery of vaccines against airborne infection is being investigated worldwide, but there is limited effort directed at developing inhaled vaccines for tuberculosis (TB). This review addresses some of the challenges confronting vaccine development for TB and attempts to link these challenges to the promises of mucosal immunity offered by pulmonary delivery. There are several approaches working toward this goal including subunit vaccines, recombinant strains, a novel vaccine strain Mycobacterium w, and DNA vaccine approaches. While it is clear that lung-resident adaptive immunity is an attainable goal, vaccine platforms must ensure that damage to the lung is limited during both vaccination and when memory cells respond to pathogenic infection. © 2010 Elsevier Ltd. All rights reserved.

Kundu B.,National Institute of Technology Rourkela | Yadav R.K.,CSIR - Central Electrochemical Research Institute | Bali B.S.,University Of Kashmir | Chowdhury S.,CSIR - Central Electrochemical Research Institute | Gahalaut V.K.,CSIR - Central Electrochemical Research Institute
Tectonics | Year: 2014

We report GPS measurements of crustal deformation across the Kashmir Himalaya. We combined these results with the published results of GPS measurements from the Karakoram fault system and suggest that in the Kashmir Himalaya, the motion between the southern Tibet and India plate is oblique with respect to the structural trend. We estimated this almost north-south oblique motion to be 17 ± 2 mm/yr, which is partitioned between dextral motion of 5 ± 2 mm/yr on the Karakoram fault system and oblique motion of 13.6 ± 1 mm/yr with an azimuth of N198E in the northwest-southeast trending Kashmir Himalayan frontal arc. Thus, the partitioning of the India-Southern Tibet oblique motion is partial in the Kashmir Himalayan frontal arc. However, in the neighboring Nepal Himalaya, there is no partitioning; the entire India-Southern Tibet motion of 19-20 mm/yr is arc normal and is accommodated entirely in the Himalayan frontal arc. The convergence rate in the Kashmir frontal Himalaya is about 25% less than that in the Nepal Himalayan region. However, here the Karakoram fault system accommodates about 20% of the southern Tibet and Indian plate convergence and marks the northern extent of the NW Himalayan arc sliver. The Kaurik Chango rift, a north-south oriented seismically active cross-wedge transtensional fault appears to divide the sliver in two parts causing varying translatory motion on the Karakoram fault on either side of the Kaurik Chango rift. ©2014. American Geophysical Union. All Rights Reserved.

Mohan M.R.,CSIR - Central Electrochemical Research Institute | Satyanarayanan M.,CSIR - Central Electrochemical Research Institute | Santosh M.,Kochi University | Santosh M.,China University of Geosciences | Sylvester P.J.,Memorial University of Newfoundland
Gondwana Research | Year: 2013

The Sittampundi Anorthosite Complex (SAC) in southern India is one of the well exposed Archean layered anorthosite-gabbro-ultramafic rock associations. Here we present high precision geochemical data for the various units of SAC, coupled with zircon U-Pb geochronology and Hf isotopic data for the anorthosite. The zircon ages define two populations, the older yield a concordia age of 2541±13Ma, which is interpreted as the best estimate of the magmatic crystallization age for the Sittampundi anorthosite. A high-grade metamorphic event at 2461±15Ma is suggested by the upper intercept age of the younger zircon population. A Neoproterozoic event at 715±180Ma resulted in Pb loss from some of the metamorphic zircons. The magmatic age of the anorthosite correlates well with the timing of crystallization of the arc-related~2530Ma magmatic charnockites in the adjacent Salem Block, while the metamorphic age is synchronous with the regional metamorphic event. The geochemical data suggest that the rocks were derived from a depleted mantle source. Sub-arc mantle metasomatism of slab derived fluids and subsequent partial melting produced hydrous, aluminous basalt magma. The magma fractionated at depth to produce a variety of high-alumina basalt compositions, from which the anorthositic complex with its chromite-rich and amphibole-rich layers formed as cumulates within the magma chamber of a supra-subduction zone arc. The coherent initial176Hf/177Hf ratios and positive εHf values (1.7 - 4.5) of the magmatic zircons in the anorthosite are consistent with derivation of a rather homogeneous juvenile parent magma from a depleted mantle source. Our study further confirms that the southern part of the Dharwar Craton was an active convergent margin during the Neoarchean with the generation and emplacement of suprasubduction zone arc magmas which played a significant role in continental growth. © 2012 International Association for Gondwana Research.

Lavania U.C.,CSIR - Central Electrochemical Research Institute | Srivastava S.,CSIR - Central Electrochemical Research Institute | Lavania S.,University of Lucknow | Basu S.,CSIR - Central Electrochemical Research Institute | And 2 more authors.
Plant Journal | Year: 2012

Whole genome duplication leads to autopolyploidy and brings about an increase in cell size, concentration of secondary metabolites and enhanced cytosine methylation. The increased cell size offers a positive advantage to polyploids for cell-surface-related activities, but there is a differential response to change in body size across species and taxonomic groups. Although polyploidy has been very extensively studied, having genetic, ecological and evolutionary implications, there is no report that underscores the significance of native secondary metabolites vis-à-vis body size with ploidy change. To address this problem we targeted unique diploid-autotetraploid paired sets of eight diverse clones of six species of Cymbopogon- a species complex of aromatic grasses that accumulate qualitatively different monoterpene essential oils (secondary metabolite) in their vegetative biomass. Based on the qualitative composition of essential oils and the plant body size relationship between the diploid versus autotetraploid paired sets, we show that polyploidy brings about enhanced accumulation of secondary metabolites in all cases, but exerts differential effects on body size in various species. It is observed that the accumulation of alcohol-type metabolites (e.g. geraniol) does not inhibit increase in body size with ploidy change from 2× to 4× (r = 0.854, P < 0.01), but aldehyde-type metabolites (e.g. citral) appear to drastically impede body development (r = -0.895). Such a differential response may be correlated to the metabolic steps involved in the synthesis of essential oil components. When changed to tetraploidy, the progenitor diploids requiring longer metabolic steps in production of their secondary metabolites are stressed, and those having shorter metabolite routes better utilize their resources for growth and vigour. In situ immunodetection of 5-methylcytosine sites reveals enhanced DNA methylation in autopolyploids. It is underpinned that the qualitative composition of secondary metabolites found in the vegetative biomass of the progenitor diploid has a decisive bearing on the body size of the derived autotetraploids and brings about an enhancement in genome-wide cytosine methylation. © 2012 The Authors. The Plant Journal © 2012 Blackwell Publishing Ltd.

Nithya C.,CSIR - Central Electrochemical Research Institute | Nithya C.,National Institute of Technology Tiruchirappalli | Gopukumar S.,CSIR - Central Electrochemical Research Institute
ChemSusChem | Year: 2013

The electrochemical performance of reduced graphite oxide (RGO) anchored with nano Sn particles, which are synthesized by a reduction method, is presented. The Sn nanoparticles are uniformly distributed on the surface of the RGO matrix and the size of the particles is approximately 5-10 nm. The uniform distribution effectively accommodates the volume expansion experienced by Sn particles during cycling. The observed electrochemical performance (97% capacity retention) can be ascribed to the flexible RGO matrix with uniform distribution of Sn particles, which reduces the lithium-ion diffusion path lengths; therefore, the RGO matrix provides more stability to the Sn particles during cycling. Such studies on Sn nanoparticles anchored on RGO matrices have not been reported to date. © 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Sunder Raju P.V.,CSIR - Central Electrochemical Research Institute | Eriksson P.G.,University of Pretoria
Geological Society Memoir | Year: 2015

The geology and basin evolutionary history of the Dharwar Craton is discussed. The Dharwar Craton comprises western (WDC) and eastern (EDC) subdivisions (possibly separated by the Closepet granite), predicated on lithological contrasts and inferred metamorphic and magmatic evolution. A postulated genesis of the WDC comprises early, c. 3.5 Ga protocrust, which possibly formed as basement to the c. 3.35-3.2 Ga Sargur Group greenstone belts. The latter are thought to have formed through accretion of plume-related ocean plateaux. The approximately coeval Peninsular Gneiss Complex possibly originated from beneath plateau remnants, leading to metamorphism of Sargur Group belts at c. 3.13-2.96 Ga. At c. 2.9-2.6 Ga, the Dharwar Supergroup, comprising lower Bababudan (mainly braided fluvial, glaciomarine and subaerial volcanic strata) and upper Chitradurga (marine clastic, chemical sedimentary and subaqueous volcanic rocks) groups developed. This supergroup formed younger greenstone belts characterized by two distinct magmatic events, at 2.7-2.6 and 2.58-2.54 Ga; the latter was approximately coeval with c. 2.6-2.5 Ga granitic magmatism, which marked final cratonization of the WDC. The EDC consists of 2.7-2.55 Ga tonalite-trondhjemite-granodiorite gneisses and migmatites, essentially coeval greenstone belts (mainly volcanic lithologies), with minor inferred remnants of an older, c. 3.38-3.0 Ga crust, and voluminous 2.56-2.5 Ga granitoids (including the Closepet). An east-west accretion of EDC island arcs (or possibly of an assembled arc-granitic terrane) on to the WDC is postulated, and the Closepet granite perhaps accreted earlier on to the WDC to form a 'central Dharwar' terrane. A final voluminous granitic cratonization event affected the assembled Dharwar Craton at c. 2.5 Ga. © 2015 The Author(s).

Anu Bhushani J.,Indian Central Food Technological Research Institute | Anu Bhushani J.,CSIR - Central Electrochemical Research Institute | Anandharamakrishnan C.,Indian Central Food Technological Research Institute | Anandharamakrishnan C.,CSIR - Central Electrochemical Research Institute
Trends in Food Science and Technology | Year: 2014

Electrohydrodynamic processes namely electrospinning and electrospraying are facile, cost effective and flexible methods that utilize electrically charged jet of polymer solution for production of fibers or particles at micron, submicron and nanoscale. The electrospun fibers and electrosprayed particles possess many structural and functional advantages. However, their use in the field of food processing and preservation remains less explored. This review provides a succinct discussion on the potential food based applications of electrospinning and electrospraying techniques such as encapsulation, enzyme immobilization, food coating and development of materials for filtration and active food packaging. Further, the existing limitations and scope for future research are underscored. © 2014 Elsevier Ltd.

Sathiya M.,CSIR - Central Electrochemical Research Institute | Prakash A.S.,CSIR - Central Electrochemical Research Institute | Ramesha K.,CSIR - Central Electrochemical Research Institute | Tarascon J.-M.,CNRS Laboratory of Chemistry and Reactivity of Solids | Shukla A.K.,Indian Institute of Science
Journal of the American Chemical Society | Year: 2011

Functionalized multiwalled carbon nanotubes (CNTs) are coated with a 4-5 nm thin layer of V2O5 by controlled hydrolysis of vanadium alkoxide. The resulting V2O5/CNT composite has been investigated for electrochemical activity with lithium ion, and the capacity value shows both faradaic and capacitive (nonfaradaic) contributions. At high rate (1 C), the capacitive behavior dominates the intercalation as 2/3 of the overall capacity value out of 2700 C/g is capacitive, while the remaining is due to Li-ion intercalation. These numbers are in agreement with the Trasatti plots and are corroborated by X-ray photoelectron spectroscopy (XPS) studies on the V2O5/CNTs electrode, which show 85% of vanadium in the +4 oxidation state after the discharge at 1 C rate. The cumulative high-capacity value is attributed to the unique property of the nano V2O 5/CNTs composite, which provides a short diffusion path for Li +-ions and an easy access to vanadium redox centers besides the high conductivity of CNTs. The composite architecture exhibits both high power density and high energy density, stressing the benefits of using carbon substrates to design high performance supercapacitor electrodes. © 2011 American Chemical Society.

Nithya C.,CSIR - Central Electrochemical Research Institute | Nithya C.,National Institute of Technology Tiruchirappalli | Gopukumar S.,CSIR - Central Electrochemical Research Institute
Journal of Materials Chemistry A | Year: 2014

Lithium ion batteries exhibit high energy and power densities, thereby making them a promising power sources for multifarious applications. However, the abundance of lithium (Li) is one of the major critical issues for using Li battery technologies. Therefore, for large-scale applications a sodium (Na) ion battery is one of the apt alternatives for portable electronics instead of expensive Li ion batteries. One of the challenging issues in Na+ ion batteries is the difficulty to understand the chemistry involved in view of the large size of the Na+ ion as compared to the Li+ ion, which makes the alloying/dealloying difficult during cycling. Hence, in this present work, we explore an innovative concept of storing Na+ ions in reduced graphene oxide/antimony (Sb) metal composites. Such a concept of storing Na+ in the rGO/Sb composite is one of the simplest ways to enhance the electrochemical performance of metal-based anodes for sodium ion batteries. Furthermore, it is seen that the nano rGO sheet transforms to nanoribbons upon galvanostatic cycling, as evidenced by TEM. © 2014 the Partner Organisations.

Chakraborty A.,CSIR - Central Electrochemical Research Institute | Ghosh S.,CSIR - Central Electrochemical Research Institute | Chowdhary G.,Jadavpur University | Maulik U.,Jadavpur University | Chakrabarti S.,CSIR - Central Electrochemical Research Institute
Nucleic Acids Research | Year: 2012

Pathogenic bacteria produce protein toxins to survive in the hostile environments defined by the host's defense systems and immune response. Recent progresses in high-throughput genome sequencing and structure determination techniques have contributed to a better understanding of mechanisms of action of the bacterial toxins at the cellular and molecular levels leading to pathogenicity. It is fair to assume that with time more and more unknown toxins will emerge not only by the discovery of newer species but also due to the genetic rearrangement of existing bacterial genomes. Hence, it is crucial to organize a systematic compilation and subsequent analyses of the inherent features of known bacterial toxins. We developed a Database for Bacterial ExoToxins (DBETH, http:// www.hpppi.iicb.res.in/btox/), which contains sequence, structure, interaction network and analytical results for 229 toxins categorized within 24 mechanistic and activity types from 26 bacterial genuses. The main objective of this database is to provide a comprehensive knowledgebase for human pathogenic bacterial toxins where various important sequence, structure and physico-chemical property based analyses are provided. Further, we have developed a prediction server attached to this database which aims to identify bacterial toxin like sequences either by establishing homology with known toxin sequences/ domains or by classifying bacterial toxin specific features using a support vector based machine learning techniques. © The Author(s) 2011.

Singh S.P.,CSIR - Central Electrochemical Research Institute | Biswas G.,Indian Institute of Technology Kanpur | Biswas G.,Indian Central Mechanical Engineering Research Institute
Journal of Fluids and Structures | Year: 2013

Vortex induced vibration (VIV) of an elastically mounted square cylinder of low non-dimensional mass is simulated at subcritical Reynolds numbers (Re), i.e., Re≤50. The cylinder is allowed to vibrate in the transverse direction to the incoming flow. Four cases are considered for understanding the behavior of VIV of the square cylinder at subcritical Re. In the first case, the non-dimensional frequency varies as 3.1875/Re. In the second case, the non-dimensional frequency is kept constant at 0.1333. In both the cases, Re is varied. In third and fourth cases, studies are conducted for Re=25, 30 and 35, and Re=80, respectively. In the third and fourth cases, the non-dimensional velocity, U*, is varied. It is found that maximum transverse displacement is approximately 0.15D when the non-dimensional frequency, Fn, varies with Re. The maximum transverse displacement is 0.25D when the non-dimensional frequency is constant. For the first case, VIV starts at Re as low as 23.9 and it ceases at Re~33.5. In all these cases, it is observed that the phase difference between the lift coefficient and the transverse displacement depends upon non-dimensional mass, Re, and non-dimensional velocity. In all the cases, the lock-in phenomenon is observed. In the fourth case of supercritical Re, hysteresis is also observed and it is seen that its extent depends upon non-dimensional mass. Stabilized finite-element space-time formulations (SUPG and PSPG) are utilized to solve the two-dimensional incompressible Navier-Stokes equations together with the equations of motion of the body. © 2013 Elsevier Ltd.

Baruah S.,CSIR - Central Electrochemical Research Institute | Kayal J.R.,Jadavpur University
Bulletin of the Seismological Society of America | Year: 2013

An attempt is made to map the spatial variation of the tectonic stress pattern in northeast India and its adjoining south Asia region using stress tensor inversion of some 516 fault-plane solutions. The Bhutan Himalaya and the Arunachal Himalaya are mapped with north-south to north-northwest-south-southeast compression. The eastern Himalaya syntaxis zone, on the other hand, shows a clockwise rotation; a north-northeast compression is dominant. To the south, in the intraplate part of the region, the Shillong plateau, Assam valley, Bengal basin (Bangladesh), and Tripura fold belt exhibit north-northwest to north-northeast compression. Orthogonal horizontal extension is dominant in southern Tibet, Bhutan, and partly in the syntaxis zone, and the same is also observed in the Shillong plateau and Assam valley area of the intraplate region. The Indo-Burma ranges and the Sagaing fault in the Myanmar region show a northeast-southwest compression; an orthogonal horizontal northwest- southeast extension is also observed in the Sagaing fault zone. A depth variation of the tectonic stress is observed below the Indo-Burma ranges; it changes from north-south to northeast-southwest in the southern part, and from northeast-southwest to northnortheast- south-southwest in the northern part in the deeper seismogenic zone. The stress inversion results of clusters of events in individual zones, though mostly conformable with the average observations, indicate a variation in the Shillong plateau due to heterogeneity and tectonic complexity.

Kandhasamy S.,Murdoch University | Nallathamby K.,CSIR - Central Electrochemical Research Institute | Minakshi M.,Murdoch University
Progress in Solid State Chemistry | Year: 2012

The high rate capability and structural stability of the olivine phosphates attracted a lot of interest as promising cathode materials for high energy density batteries. Alteration on these cathode materials, for instance, reducing particle size, conductive coating and metal ion doping were performed in order to improve the conductivity and to obtain high specific capacity. Wide range of transition metal ions with range of valences (M 1+ to M 5+) was successfully doped both in M 1 site (Li) and M 2 site (M) of olivine LiMPO 4 (M = Fe, Mn, Co and Ni) cathode. The large charge difference between the doped supervalent ions and M cations at the M 2 site, limited the use of supervalent cations in the olivines. However, the supervalent dopants (namely; Cr 3+, Ti 4+, Nb 5+) are reported to be successfully substituted in the olivine with an improvement in electrical and ionic conductivity. The amount of defect can be reduced by low concentration of dopants, choosing suitable synthesis method and optimized reaction conditions. Charge compensation vacancies accomplished through aliovalent doping reduces the grain size and widens the Li + migration path resulting in faster Li + diffusion. However, the drastic improvement in electrical conductivity for the aliovalent doping is still unclear. Rather writing a lengthy standard review, this manuscript intends to describe briefly the lattice defects owing to metal ion doping and its influence in improving the cathode performance of the olivine phosphates. This gives a new approach in this field. © 2012 Elsevier Ltd. All rights reserved.

Nithya C.,National Institute of Technology Tiruchirappalli | Gopukumar S.,CSIR - Central Electrochemical Research Institute
Wiley Interdisciplinary Reviews: Energy and Environment | Year: 2015

Vehicle electrification is one of the most significant solutions that address the challenges of fossil fuel depletion, global warming, CO2 pollution, and so on. To mitigate these issues, recent research mainly focuses on finding clean energy storage devices such as batteries, supercapacitors, fuel cells, and so forth. Owing to the outstanding energy and power density, lithium-ion batteries (LIB) have captured the market for portable electronics, hybrid electric vehicles, plug-in hybrid electric vehicles, and so on. During 1970-1980s, electrode materials for both LIBs and sodium-ion batteries (NIBs) were investigated but higher energy and power density of LIBs have made it a popular candidate for portable electronics. Issues arise on the availability of lithium reserves, so it is high time we take a look at finding alternative energy storage system without compromising on the energy and power density of the state-of-the-art LIBs. Therefore, researchers have revisited NIBs and recent developments have contributed towards discovering new electrode materials to match the energy and power density of LIBs at low cost. While a variety of positive and negative electrode materials have been investigated for NIBs so far, the influence of voltage, capacity, cycle life, and volume expansion of negative electrodes on Na+ ion extraction and insertion are more as compared with LIBs. This affects the energy and power density of NIBs but cost-effective partial replacement of LIBs is viable and is widely pursued. © 2014 John Wiley & Sons, Ltd.

Saravanan M.,CSIR - Central Electrochemical Research Institute | Saravanan M.,Indian Central Food Technological Research Institute | Ganesan M.,CSIR - Central Electrochemical Research Institute | Ambalavanan S.,CSIR - Central Electrochemical Research Institute
Journal of Power Sources | Year: 2014

In this work, we report an in situ generated carbon from sugar as additive in the Negative Active Mass (NAM) which enhances the charge-discharge characteristics of the lead-acid cells. In situ formed sugar derived carbon (SDC) with leady oxide (LO) provides a conductive network and excellent protection against NAM irreversible lead sulfation. The effect of SDC and carbon black (CB) added negative plates are characterized by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), galvanostatic charge-discharge, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), respectively. The results show that subtle changes in the addition of carbon to NAM led to subsequent changes on the performance during partial-state-of-charge (PSoC) operations in lead-acid cells. Furthermore, SDC added cells exhibit remarkable improvement in the rate capability, active material utilization, cycle performance and charge acceptance compared to that of the conventional CB added cells. The impact of SDC with LO at various synthesis conditions on the electrochemical performance of the negative plate is studied systematically. © 2013 Elsevier B.V. All rights reserved.

Bhowmick S.K.,CSIR - Central Electrochemical Research Institute | Amritkar R.E.,Physical Research Laboratory | Dana S.K.,CSIR - Central Electrochemical Research Institute
Chaos | Year: 2012

We investigate synchronization of time varying networks and stability conditions. We derive interesting relations between the critical coupling constants for synchronization and switching times for time-varying and time average networks. The relations are based on the additive property of Lyapunov exponents and are verified experimentally in electronic circuit. © 2012 American Institute of Physics.

Devadas A.,University of Poitiers | Vasudevan S.,CSIR - Central Electrochemical Research Institute | Epron F.,University of Poitiers
Journal of Hazardous Materials | Year: 2011

An attempt is made to improve the catalytic nitrate reduction on Pd/CeO2 catalysts by the addition of a second metal. The influence of the second metal such as Sn, In and Ag on the Pd/CeO2 for nitrate reduction is explored. The second metal is introduced over monometallic Pd/CeO2 by a redox reaction. Pd/CeO2 is more active than the bimetallic catalysts under pure hydrogen flow. Whereas in presence of CO2 the monometallic Pd/CeO2 is inactive for nitrate reduction, bimetallic catalysts are found to be more active than under pure hydrogen flow and also than the monometallic catalyst with a low selectivity towards ammonium ions, undesired product of the reaction. The Pd-Sn/CeO2 catalyst is comparatively the most suited for nitrate reduction. © 2010 Elsevier B.V.

De D.,CSIR - Central Electrochemical Research Institute | Chakraborty P.D.,Albert David Ltd. | Bhattacharyya D.,CSIR - Central Electrochemical Research Institute
Journal of Cellular Physiology | Year: 2011

An aqueous extract of human placenta, used as wound healer, shows stabilization of trypsin against autodigestion as one of the peptides of the extract binds very strongly with the protease. Trypsin retains 40% of activity at constant level between 20 and 26 days in presence of the extract against complete inactivation in its absence. Inhibition of esterolytic activity and inability to react with p-nitrophenyl-p'-guanidinobenzoate, HCl, an active site directed reagent, by trypsin in presence of a peptide fraction of the extract indicated blocking of the catalytic site of the enzyme. Rayleigh scattering, size-exclusion HPLC, fluorescence resonance energy transfer, and surface plasmon resonance show that fibronectin type III-like peptide present in the extract interacts with trypsin. The peptide-trypsin complex is dissociated in presence of high concentration of substrates. Thus, regulation of trypsin activity by the placental extract is evident. © 2010 Wiley-Liss, Inc..

Berchmans S.,CSIR - Central Electrochemical Research Institute | Issa T.B.,Murdoch University | Singh P.,Murdoch University
Analytica Chimica Acta | Year: 2012

Determination of inorganic phosphate is of very high importance in environmental and health care applications. Hence knowledge of suitable analytical techniques available for phosphate sensing for different applications becomes essential. Electrochemical methods for determining inorganic phosphate have several advantages over other common techniques, including detection selectivity, stability and relative environmental insensitivity of electroactive labels. The different electrochemical sensing strategies adopted for the determination of phosphate using selective ionophores are discussed in this review. The various sensing strategies are classified based on the electrochemical detection techniques used viz., potentiometry, voltammetry, amperometry, unconventional electrochemical methods etc., The enzymatic sensing of phosphate coupled with electrochemical detection is also included. Various electroanalytical methods available in the literature are assessed for their merits in terms of selectivity, simplicity, miniaturisation, adaptability and suitability for field measurements. © 2012 Elsevier B.V.

Garai S.,Indian National Metallurgical Laboratory | Garai S.,CSIR - Central Electrochemical Research Institute | Jaisankar P.,CSIR - Central Electrochemical Research Institute | Singh J.K.,Indian National Metallurgical Laboratory | Elango A.,Jadavpur University
Corrosion Science | Year: 2012

Corrosion inhibition effects of crude methanolic extract of Artemisia pallens on mild steel in 1moll -1 HCl were studied by weight loss and electrochemical technique. Arbutin, an active principle from A. pallens and the crude methanolic extract exhibited inhibition efficiency of 93% and 98% in 400mgl -1 concentration at 30°C respectively. The results indicated that arbutin in acidic medium acted as good anti-corrosive agent synergistically with its hydrolyzed products hydroquinone and d-glucose. Adsorption of both the inhibitors on mild steel surface conformed to the Langmuir isotherm with standard adsorption free energy of -33.07kJmol -1 for arbutin. © 2012 Elsevier Ltd.

Sathiya M.,CSIR - Central Electrochemical Research Institute | Hemalatha K.,CSIR - Central Electrochemical Research Institute | Ramesha K.,CSIR - Central Electrochemical Research Institute | Tarascon J.-M.,CNRS Laboratory of Chemistry and Reactivity of Solids | Prakash A.S.,CSIR - Central Electrochemical Research Institute
Chemistry of Materials | Year: 2012

A layered phase, NaNi 1/3Mn 1/3Co 1/3O 2 (NaNMC), isostructural to NaCoO 2 has been synthesized. Stoichiometric NaNMC crystallizes in a rhombohedral R3̄m space group where Na is in an octahedral environment (O3-Type). Galvanostatic cycling on NaNMC vs Na cell indicated a reversible intercalation of 0.5 Na, leading to a capacity of 120 mAh•g -1 in the voltage range of 2-3.75 V and indicating its possible application in Na-ion batteries. The electrochemically driven Na insertion/deinsertion in NaNMC is associated with several phase transitions and solid solution regimes which are studied by in situ X-ray diffraction. Sodium deinsertion in Na xNMC resulted in sequential phase transitions composed of biphasic and monophasic domains. The composition driven structural evolution in Na xNMC follows the sequence O3 O1 P3 P1 phases with an increased 'c' parameter, while the 'a' parameter remains almost unchanged. © 2012 American Chemical Society.

Soni K.,CSIR - Central Electrochemical Research Institute | Choudhary A.,CSIR - Central Electrochemical Research Institute | Patowary A.,CSIR - Central Electrochemical Research Institute | Singh A.R.,CSIR - Central Electrochemical Research Institute | And 4 more authors.
Nucleic Acids Research | Year: 2013

MicroRNAs (miRNAs) are small, endogenous, regulatory RNA molecules that can bind to partially complementary regions on target messenger RNAs and impede their expression or translation. We rationalized that miRNAs, being localized to the cytoplasm, will be maternally inherited during fertilization and may play a role in early development. Although Dicer is known to be essential for the transition from single-celled zygote to two-cell embryo, a direct role for miRNAs has not yet been demonstrated. We identified miRNAs with targets in zygotically expressed transcripts in Drosophila using a combination of transcriptome analysis and miRNA target prediction. We experimentally established that Drosophila miRNA dme-miR-34, the fly homologue of the cancer-related mammalian miRNA miR-34, involved in somatic-cell reprogramming and having critical role in early neuronal differentiation, is present in Drosophila embryos before initiation of zygotic transcription. We also show that the Drosophila miR-34 is dependent on maternal Dicer-1 for its expression in oocytes. Further, we show that miR-34 is also abundant in unfertilized oocytes of zebrafish. Its temporal expression profile during early development showed abundant expression in unfertilized oocytes that gradually decreased by 5 days post-fertilization (dpf). We find that knocking down the maternal, but not the zygotic, miR-34 led to developmental defects in the neuronal system during early embryonic development in zebrafish. Here, we report for the first time, the maternal inheritance of an miRNA involved in development of the neuronal system in a vertebrate model system. © 2013 The Author(s).

Verma S.K.,CSIR - Central Electrochemical Research Institute | Goswami G.K.,Central Bureau of Investigation Academy
Forensic Science International | Year: 2014

Since the discovery of DNA fingerprinting technology in 1985 it has been used extensively as evidence in the court of law world-wide to establish the individual identity both in civil and criminal matters. In India, the first case of parentage dispute solved by the use of DNA fingerprinting technology was in 1989. Since then till date, the DNA technology has been used not only to resolve the cases of paternity and maternity disputes, but also for the establishment of individual identity in various criminal cases and for wildlife forensic identification. Since last half a decade, India is exercising to enact legislation on the use of DNA in the judicial realm and the draft 'Human DNA Bill-2012' is pending in the parliament. Largely, the promoters of forensic DNA testing have anticipated that DNA tests are nearly infallible and DNA technology could be the greatest single advance step in search for truth, conviction of the perpetrator, and acquittal of the innocent. The current article provides a comprehensive review on the status of DNA testing in India and elucidates the consequences of the admissibility of DNA as 'evidence' in the judicial dominion. In this backdrop of civil and criminal laws and changing ethical and societal attitudes, it is concluded that the DNA legislation in India and world-wide needs to be designed with utmost care. © 2014 Elsevier Ireland Ltd.

Bhuyan D.,CSIR - Central Electrochemical Research Institute | Sarma R.,Nalbari College | Dommaraju Y.,CSIR - Central Electrochemical Research Institute | Prajapati D.,CSIR - Central Electrochemical Research Institute
Green Chemistry | Year: 2014

A pot, atom and step economic (PASE) synthesis of tetrahydroquinazolines has been achieved via a microwave-assisted four-component catalyst- and solvent-free aza-Diels-Alder reaction strategy. The key step of the methodology is the in situ generation of both the diene and the dienophile and their subsequent reaction to give the desired product. © 2014 The Royal Society of Chemistry.

Liu Y.,China University of Petroleum - Beijing | Sen M.K.,University of Texas at Austin | Sen M.K.,CSIR - Central Electrochemical Research Institute
Journal of Computational Physics | Year: 2013

High-order finite-difference (FD) methods have been widely used for numerical solution of acoustic wave equations. It has been reported that the modeling accuracy is of 2nd-order when the conventional (2. M)th-order space domain FD and the 2nd-order time domain FD stencils are directly used to solve the acoustic wave equation. Under the same discretization, the present version of time-space domain dispersion-relation-based FD method can improve the accuracy from 2nd-order to (2. M)th-order along eight directions for the 2D acoustic wave equation. To increase the accuracy further, we propose a new FD stencil for 2D acoustic wave equation modeling. This new time-space domain dispersion-relation-based FD stencil can reach the same arbitrary even-order accuracy along all directions, and is more accurate and more stable than the conventional one for the same M. Dispersion analysis and modeling examples demonstrate its advantages. © 2012 Elsevier Inc.

Senthil Kumar R.,CSIR - Central Electrochemical Research Institute | Senthil Kumar S.,University of Texas at Austin | Anbu Kulandainathan M.,CSIR - Central Electrochemical Research Institute
Microporous and Mesoporous Materials | Year: 2013

Cu3(BTC)2 (Metal organic frameworks-MOF) synthesized through electrochemical route and is used as an catalyst for chemical reduction of nitrophenol in the presence of excess NaBH4. Optimization studies for the electrochemical parameters have been demonstrated in order to get 97.51% yield with respect to copper dissolution. Synthesized Cu3(BTC) 2 is characterized by XRD, FT-IR, SEM, TEM, EDX, BET, TGA and XPS and the results reveal that supporting electrolyte, current density play a crucial role in controlling the particle size and also improving the yield of MOF. The SEM and TEM studies show that the morphology of the synthesized particles is cubic in nature and the particle size is ∼10-20 nm. The oxidation state of Cu in the synthesized Cu3(BTC)2 found to be +2 from XPS studies. Synthesized Cu3(BTC)2-MOF function as an effective catalyst to activate the reduction of p -nitrophenol to p-aminophenol in the presence of excess NaBH4 and the calculated apparent rate constant of 8.69 × 10-2 s-1 is found to be higher than the other supported noble metal nanoparticle and polymer nanocomposites. © 2012 Elsevier Inc. All rights reserved.

Narayan R.,CSIR - Central Electrochemical Research Institute | Kumar P.,Jawaharlal Nehru Centre for Advanced Scientific Research | Narayan K.S.,Jawaharlal Nehru Centre for Advanced Scientific Research | Asha S.K.,CSIR - Central Electrochemical Research Institute
Advanced Functional Materials | Year: 2013

Well defined nanostructured polymeric supramolecular assemblies are formed when an asymmetric perylenebisimide substituted with ethylhexyl chains on one end and functionalized with 3-pentadecylphenol at the other termini (PDP-UPBI) is complexed with poly(4-vinylpyridine) (P4VP) via a non-covalent specific interaction such as hydrogen-bonding. The resulting P4VP(PDP-UPBI)n complexes are fully solution processable. The bulk structure and morphologies of the supramolecular film studied using small angle and wide angle X-ray scattering reveals highly crystalline nature of the complex. Thin film morphology of the 1:1 complex analyzed using transmission electron microscopy shows uniform lamellar structures in the domain range of 5-10 nm. A clear trend of improved electrical parameters in P4VP(PDP-UPBI) system compared to pristine (PDP-UPBI) is observed from space charge limited current measurements. In short, a simple and facile method to obtain spatially defined organization of n-type semiconductor perylenebisimide molecules using hydrogen bonding interactions with P4VP as the structural motif is showcased herein. Supramolecular complex formation of an asymmetrical perylenebisimide (PDP-UPBI) with poly(4-vinylpyridine) (P4VP) via non-covalent specific interaction such as hydrogen bonding is described. The complexation results in the formation of uniform lamellar structures in the domain range of 5-10 nm. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Kitoh A.,Meteorological Research Institute | Endo H.,Meteorological Research Institute | Krishna Kumar K.,Indian Institute of Tropical Meteorology | Cavalcanti I.F.A.,National Institute for Space Research | And 2 more authors.
Journal of Geophysical Research: Atmospheres | Year: 2013

We provide a new view of global and regional monsoonal rainfall, and their changes in the 21st century under RCP4.5 and RCP8.5 scenarios as projected by 29 climate models that participated in the Coupled Model Intercomparison Project phase 5. The model results show that the global monsoon area defined by the annual range in precipitation is projected to expand mainly over the central to eastern tropical Pacific, the southern Indian Ocean, and eastern Asia. The global monsoon precipitation intensity and the global monsoon total precipitation are also projected to increase. Indices of heavy precipitation are projected to increase much more than those for mean precipitation. Over the Asian monsoon domain, projected changes in extreme precipitation indices are larger than over other monsoon domains, indicating the strong sensitivity of Asian monsoon to global warming. Over the American and African monsoon regions, projected future changes in mean precipitation are rather modest, but those in precipitation extremes are large. Models project that monsoon retreat dates will delay, while onset dates will either advance or show no change, resulting in lengthening of the monsoon season. However, models' limited ability to reproduce the present monsoon climate and the large scatter among the model projections limit the confidence in the results. The projected increase of the global monsoon precipitation can be attributed to an increase of moisture convergence due to increased surface evaporation and water vapor in the air column although offset to a certain extent by the weakening of the monsoon circulation. ©2013. American Geophysical Union. All Rights Reserved.

Senthil Kumar S.,University of Texas at Austin | Senthil Kumar S.,CSIR - Central Electrochemical Research Institute | Bard A.J.,University of Texas at Austin
Analytical Chemistry | Year: 2013

The background electrogenerated chemiluminescence (ECL) emission observed only upon electrochemical oxidation of tri-n-propylamine (TPrAH) on a platinum electrode is a limiting factor in ECL analytical techniques and is poorly understood. We studied this reaction in aerated acetonitrile (MeCN) solution with TPrAH oxidized at a constant potential at the Pt surface and observed ECL spectra with an emission band at 630 nm, which is characteristic of the emission of the dimeric 1Δg state of O2. No ECL emission was observed when the same solution was deaerated. This background ECL emission is attributed to the reaction between dissolved oxygen and two different products of TPrAH oxidation: the TPrAH• radical that reduces O2 to the superoxide ion and the TPrAH•+ radical cation that oxidizes this species to singlet O2. © 2012 American Chemical Society.

Zhang R.,University of Texas at Austin | Sen M.K.,University of Texas at Austin | Sen M.K.,CSIR - Central Electrochemical Research Institute | Srinivasan S.,University of Texas at Austin
Geophysics | Year: 2013

Resolving thin layers and clearly delineating layer boundaries in inverted seismic sections are very important goals for exploration and production. Many seismic inversion methods based on a least-squares optimization approach with Tikhonov-type regularization can lead to unfocused transitions between adjacent layers. A basis pursuit inversion (BPI) algorithm based on the L1 norm optimization method can, however, resolve sharp boundaries between layers. We have formulated a BPI algorithm for amplitude-versus-angle inversion and investigated its potential to improve contrasts between layers. Like the BPI for poststack case, the sparse layer constraint, rather than the sparse spike constraint, is used to construct the model space as a wedge dictionary. All the elements of the dictionary are bed reflectivities, which include solutions consisting of thin beds as well. With this dictionary, we use an L1 norm optimization framework to derive three reflectivities, namely, Rp, Rs, and Rρ Although BPI does not require a starting model, highresolution absolute velocities (VP, VS) and density (ρ) can be obtained by incorporating initial models in the BPI derived reflectivities. Tests on synthetic and field data show that the BPI algorithm can indeed detect and enhance layer boundaries by effectively removing the wavelet interference. © 2012 Society of Exploration Geophysicists.

Late D.J.,CSIR - National Chemical Laboratory | Shirodkar S.N.,Jawaharlal Nehru Centre for Advanced Scientific Research | Waghmare U.V.,Jawaharlal Nehru Centre for Advanced Scientific Research | Dravid V.P.,Northwestern University | Rao C.N.R.,CSIR - Central Electrochemical Research Institute
ChemPhysChem | Year: 2014

We report the temperature-dependent Raman spectra of single- and few-layer MoSe2 and WSe2 in the range 77-700 K. We observed linear variation in the peak positions and widths of the bands arising from contributions of anharmonicity and thermal expansion. After characterization using atomic force microscopy and high-resolution transmission electron microscopy, the temperature coefficients of the Raman modes were determined. Interestingly, the temperature coefficient of the A22u mode is larger than that of the A1g mode, the latter being much smaller than the corresponding temperature coefficients of the same mode in single-layer MoS2 and of the G band of graphene. The temperature coefficients of the two modes in single-layer MoSe2 are larger than those of the same modes in single-layer WSe2. We have estimated thermal expansion coefficients and temperature dependence of the vibrational frequencies of MoS2 and MoSe2 within a quasi-harmonic approximation, with inputs from first-principles calculations based on density functional theory. We show that the contrasting temperature dependence of the Raman-active mode A1g in MoS2 and MoSe2 arises essentially from the difference in their strain-phonon coupling. Special effects in 2D: The temperature-dependent Raman spectra of single- and few-layer MoSe2 and WSe2 in the 77-700 K range are reported. Linear variation is observed in the peak positions and widths of the bands arising from contributions of anharmonicity and thermal expansion. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Demir-Cakan R.,University of Picardie Jules Verne | Morcrette M.,University of Picardie Jules Verne | Gangulibabu,University of Picardie Jules Verne | Gangulibabu,CSIR - Central Electrochemical Research Institute | And 5 more authors.
Energy and Environmental Science | Year: 2013

Although promising improvements have been made in the field of Li-S rechargeable batteries, they are still far from reaching the market place due to several drawbacks. To combat the solubility of polysulphides, confinement approaches aiming to trap sulphur within the cathode side have been pursued, but success has been limited. Herein, we drastically deviate from this approach and use a liquid cathode obtained either by dissolving polysulphides within the electrolyte or by placing sulphur powders in contact with the Li negative electrode. Such approaches are shown to result in greater performance than confinement approaches. Such a strategy eliminates the detrimental Li 2S formation inside a porous carbon matrix and moreover leads to the formation of a protective SEI layer at the Li electrode, as deduced by impedance spectroscopy and XPS, which seems beneficial to the cell cycling performance. © The Royal Society of Chemistry 2013.

Senthil Kumar R.,CSIR - Central Electrochemical Research Institute | Senthil Kumar S.,University of Texas at Austin | Anbu Kulandainathan M.,CSIR - Central Electrochemical Research Institute
Electrochemistry Communications | Year: 2012

The electrocatalytic reduction of carbon dioxide at Cu based metal organic framework film surface was studied in N,N-dimethylformamide containing tetrabutylammonium tetrafluoroborate with saturated CO 2. Cyclic voltammetric studies of the MOF film immobilized onto GC in 0.1 M KCl clearly showed the well defined Cu(II)/Cu(I) and Cu(I)/Cu(0) reversible redox responses. In the presence of saturated CO 2/TBATFB/DMF solution, the cyclic voltammetric studies revealed that the electrochemically generated Cu(I) formed adduct with carbon dioxide in-situ and on further formed oxalic acid. The formation of oxalic acid was confirmed by GCMS in bulk electrolysis experiment. A detailed mechanism for the formation of oxalic acid was also discussed in this communication. © 2012 Elsevier B.V.

Kolhe N.B.,CSIR - Central Electrochemical Research Institute | Ashar A.Z.,Jawaharlal Nehru Centre for Advanced Scientific Research | Narayan K.S.,Jawaharlal Nehru Centre for Advanced Scientific Research | Asha S.K.,CSIR - Central Electrochemical Research Institute
Macromolecules | Year: 2014

A series of alternating and random donor (D)-acceptor (A) copolymers based on naphthalene diimide (NDI) as the acceptor and oligo(p-phenylenevinylene) (OPV) or benzobisoxazole (BBO) as the strong and weak donor, respectively, were designed and synthesized by Suzuki coupling and Horner-Wadsworth-Emmons polymerization. The effect of the varying donor strength of OPV and BBO on the photophysical, electrochemical, and semiconducting properties of the polymers was investigated. Absorption and emission spectra recorded for dilute chloroform solution and thin film showed increased intramolecular charge transfer for NDI-alt-OPV polymer compared to NDI-alt-BBO polymer. Cyclic voltammetry studies along with DFT (density functional theory) studies at the B3LYP/6-31g* level gave insight into the energy level (HOMO/LUMO) and molecular orientation of donor and acceptor along the polymer backbone. NDI-alt-OPV polymer exhibited rigid coplanar structure with extended π-conjugation which induced backbone planarity and crystallinity to the polymer. The inherent poor solubility of the NDI-alt-BBO prevented further device characterization of this polymer. Random copolymer having maximum 30% incorporation of BBO comonomer in NDI-r-OPV/BBO was found to be soluble for further characterization. Compared to NDI-alt-OPV, lowering of both energy levels LUMO (∼0.2 eV) and HOMO (∼0.5 eV) was observed for both NDI-alt-BBO and the NDI-r-OPV/BBO. Bottom gate-top contact organic field effect transistors (OFETs) of NDI-alt-OPV exhibited balanced ambipolar charge transport with average electron and hole mobility of 3.09 × 10-3 cm2 V-1s-1 and 2.1 × 10-3 cm2 V-1 s-1, respectively, whereas the random copolymer incorporating both OPV and BBO units NDI-r-OPV/BBO showed dominant n-type charge transport with moderate 4 × 10-4 cm2 V-1 s-1 average electron mobility. The present work thus highlights the structure-property relationship and the electronic tunability required in this class of NDI-based polymers to produce ambipolar transistors. © 2014 American Chemical Society.

Absar N.,Pondicherry University | Sreenivas B.,CSIR - Central Electrochemical Research Institute
International Geology Review | Year: 2015

Geochemical and petrological studies of the well-preserved greywacke horizon of the Middle Aravalli Group were carried out to constrain the early evolution of the Aravalli basin. Petrological and geochemical attributes of Middle Aravalli greywackes (MAGs) such as very poor sorting, high angularity of framework grains, presence of fresh plagioclase and K-feldspars, variable Chemical Index of Alteration (CIA) index (46.7-74.5, avg. 61), and high Index of Compositional Variability (ICV) value (~1.05) suggest rapid physical erosion accompanying an active tectonic regime. The sediments record post-depositional K-metasomatism and extraneous addition of 0-25% (avg. ~10%) K is indicated. Assuming close system behaviour of immobile elements during sedimentation, various diagnostic element ratios such as Th/Sc, La/Sc, Zr/Sc, and Co/Th, Eu anomaly and rare earth element patterns of MAG suggest that the Archaean Banded Gneissic Complex (BGC) basement was not the major source of sediments. In conjunction with the dominant 1.8-1.6 Ga detrital zircon age peaks of Middle Aravalli clastic rocks, these data rather indicate that the sediments were derived from a young differentiated continental margin-type arc of andesite-dacite-rhyodacite composition. A highly fractionated mid-oceanic-ridge-basalt-normalized trace element pattern of MAGs, with characteristic enrichment of large-ion lithophile elements (LILEs), depletion of heavy rare earth elements, negative Nb-Ta, Ti and P anomalies, positive Pb anomaly, and distinctive Nb/Ta, Zr/Sm, Th/Yb, and Ta/Yb, Ce/Pb ratios envelop the composition of modern continental arc magmas (andesite-dacite) of the Andes, suggesting a subduction zone tectonic setting for precursor magma. High magnitude of LILE enrichment and high Th/Yb ratios in these sediments indicate that thick continental crust (~70 km) underlay the Middle Aravalli continental arc, similar to the Central Volcanic Zone of the modern Andes. We propose that eastward subduction of Delwara oceanic crust beneath the BGC continent led to the formation of a continental volcanic arc, which supplied detritus to the forearc basin situated to the west. This model also explains the opening of linear ensialic basins in the Bhilwara terrain, such as in Rajpura-Dariba and Rampura-Agucha in a classical back-arc extension regime, similar to the Andean continental margin of the Mesozoic. On the basis of the recent 207Pb/206Pb detrital zircon age of Middle Aravalli sediment, a time frame between 1772 and 1586 Ma can be assigned for Middle Aravalli continental arc magmatism. © 2015 Taylor & Francis.

Raj A.,Indian Institute of Toxicology Research | Kumar S.,Indian Institute of Toxicology Research | Haq I.,Indian Institute of Toxicology Research | Singh S.K.,CSIR - Central Electrochemical Research Institute
Ecological Engineering | Year: 2014

The present study deals with the bioremediation of potentially hazardous pulp and paper mill effluent by a laccase producing Paenibacillus sp. strain LD-1 (JX499920) isolated from contaminated soil sample by lignin enrichment method. The bacterium effectively reduced pollution parameters (colour 68%, lignin 54%, phenol 86%, BOD 83% and COD 78%) after 144. h of treatment at 34. ±. 1. °C and 120. rpm. GC-MS analysis of control and treated samples showed that concentration of most of the low molecular weight phenolic compounds like 2-methoxyphenol, 2,6-dimethoxy phenol, 2-methoxy-4-ethyl-phenol, 3-allyl-6-methoxyphenol, ethanone 1-(-4-hydroxy-3,5-dimethoxyphenyl), benzoic acid, 2-methoxy-4-(1-propenyl) phenol and 4-methoxycinnamic acid present in control untreated effluent were reduced after bacterial treatment. The toxicity assessments were carried out with treated and untreated effluent by studying the growth and germination of seeds of mung bean (Vigna radiata L.). The mung bean bioassay confirmed the detoxification of effluent after bacterial treatment. © 2014 Elsevier B.V.

Sarma D.S.,CSIR - Central Electrochemical Research Institute | McNaughton N.J.,Curtin University Australia | Belusova E.,Macquarie University | Ram Mohan M.,CSIR - Central Electrochemical Research Institute | Fletcher I.R.,Curtin University Australia
Gondwana Research | Year: 2012

The Western Dharwar Craton in peninsular India comprises a typical Meso- to Neo-Archean granite-greenstone terrain. Detrital zircons from two metagreywackes in a late basin from the Gadag Greenstone Belt preserve at least eight age populations ranging in age from ca 3.34 to 2.55Ga, and grains as old as ca 3.54Ga. The zircon provenances for the two samples appear to be the same up to ca 3.25Ga, with relatively juvenile ε Hf values largely between zero and depleted mantle values. After 3.25Ga, one sample has similar ε Hf values whereas the other has only negative values indicative of Hf-evolution in a crustal environment. After ca 3.25Ga the source regions for the two samples were distinctly different.The detrital zircons reflect the age and evolution of the upper crust of the Western Dharwar Craton. Modeling of Hf isotopic evolution of the detrital zircons suggests two major crust-forming events at ca. 3.6 and 3.36. Ga, and some indication of juvenile addition to the crust at ca 2.6. Ga. The maximum sedimentation age of the greywackes is constrained by the youngest detrital zircon population at 2547 ± 5. Ma. Gold mineralization in the belt is dated at 2522 ± 6. Ma and constrains greywacke sedimentation, deformation and metamorphism to a ca 25. my interval. © 2012 International Association for Gondwana Research.

Harshvardhan K.,Indian Central Salt and Marine Chemicals Research Institute | Harshvardhan K.,CSIR - Central Electrochemical Research Institute | Jha B.,Indian Central Salt and Marine Chemicals Research Institute | Jha B.,CSIR - Central Electrochemical Research Institute
Marine Pollution Bulletin | Year: 2013

Sixty marine bacteria isolated from pelagic waters were screened for their ability to degrade low-density polyethylene; among them, three were positive and able to grow in a medium containing polythene as the sole carbon source. The positive isolates were identified as Kocuria palustris M16, Bacillus pumilus M27 and Bacillus subtilis H1584 based on the 16S rRNA gene sequence homology. The weight loss of polyethylene was 1%, 1.5% and 1.75% after 30. days of incubation with the M16, M27 and H1584 isolates, respectively. The maximum (32%) cell surface hydrophobicity was observed in M16, followed by the H1584 and M27 isolates. The viability of the isolates growing on the polyethylene surface was confirmed using a triphenyltetrazolium chloride reduction test. The viability was also correlated with a concomitant increase in the protein density of the biomass. Polyethylene biodegradation was further confirmed by an increase in the Keto Carbonyl Bond Index, the Ester Carbonyl Bond Index and the Vinyl Bond Index, which were calculated from FT-IR spectra. © 2013 Elsevier Ltd.

Shukla R.K.,Indian Institute of Toxicology Research | Kumar A.,Indian Institute of Toxicology Research | Gurbani D.,Indian Institute of Toxicology Research | Pandey A.K.,Indian Institute of Toxicology Research | And 2 more authors.
Nanotoxicology | Year: 2013

Titanium dioxide nanoparticles (TiO2 NPs), widely used in consumer products, paints, pharmaceutical preparations and so on, have been shown to induce cytotoxicity, genotoxicity and carcinogenic responses in vitro and in vivo. The present study revealed that TiO2 NPs induce significant (p < 0.05) oxidative DNA damage by the Fpg-Comet assay even at 1 g/ml concentration. A corresponding increase in the micronucleus frequency was also observed. This could be attributed to the reduced glutathione levels with concomitant increase in lipid peroxidation and reactive oxygen species generation. Furthermore, immunoblot analysis revealed an increased expression of p53, BAX, Cyto-c, Apaf-1, caspase-9 and caspase-3 and decreased the level of Bcl-2 thereby indicating that apoptosis induced by TiO2 NPs occurs via the caspase-dependent pathway. This study systematically shows that TiO2 NPs induce DNA damage and cause apoptosis in HepG2 cells even at very low concentrations. Hence the use of such nanoparticles should be carefully monitored. © Informa UK, Ltd. © 2013 Informa UK, Ltd.

Bharmoria P.,CSIR - Central Electrochemical Research Institute | Rao K.S.,CSIR - Central Electrochemical Research Institute | Trivedi T.J.,CSIR - Central Electrochemical Research Institute | Kumar A.,CSIR - Central Electrochemical Research Institute | Kumar A.,Indian Central Salt and Marine Chemicals Research Institute
Journal of Physical Chemistry B | Year: 2014

3-Methyl-1-octylimidazolium dodecylsulfate, [C8mim][C 12OSO3], a vesicle forming biamphiphilic ionic liquid (BAIL) (J. Phys. Chem. B 2012, 116, 14363-14374), has been found to induce significant folding alterations in the structure of bovine serum albumin (BSA) in the aqueous medium at pH 7.0. Such alterations have been investigated in detail using various physicochemical and spectroscopic techniques. Different concentration regimes (monomeric, shared aggregation, and post-vesicular) of [C8mim][C12OSO3]-BSA interactions have been defined through adsorption and binding isotherms using tensiometry and isothermal titration calorimetry (ITC). Fluorimetry, circular dichroism (CD), and dynamic light scattering (DLS) measurements have shown that [C 8mim][C12OSO3] induces a small unfolding of BSA in the monomeric regime at low concentration (designated as Cf), which is followed by a refolding up to critical aggregation concentration (CAC) (designated as C1). Above C1, i.e., in the shared aggregation concentration regime, again a small unfolding of BSA was observed up to critical vesicular concentration (CVC) (designated as C2). In the vesicular and post-vesicular regimes, the BSA remained stable against folding alterations. The kinetic stability of BSA in the vesicular concentration regimes was studied for a month using turbidimetry. It has been found that [C 8mim][C12OSO3] stabilizes BSA against the aggregation which is the major cause of protein destabilization. The present study gives insights for the design of surface active ILs for protein stabilization as a potential replacement for the mixed micelles of conventional surfactants used in detergent industries for enzyme stabilization and as an artificial chaperone. © 2013 American Chemical Society.

Azarudeen R.S.,Oxford Engineering College | Subha R.,Oxford Engineering College | Jeyakumar D.,CSIR - Central Electrochemical Research Institute | Burkanudeen A.R.,Jamal Mohamed College Autonomous
Separation and Purification Technology | Year: 2013

Chelating terpolymer resin was synthesized from anthranilic acid and 2-amino pyridine with formaldehyde to remove the heavy metal ions present in the solutions. The synthesized terpolymer resin was characterized by spectral techniques such as FTIR, NMR (1H and 13C) and elemental analysis to elucidate the structure of the resin. The physico-chemical parameters have also been evaluated for the terpolymer resin. The surface morphology of the terpolymer resin without the metal ion uptake and with the incorporation of the metal ion was examined by scanning electron microscopy. The chelation ion-exchange property of the terpolymer resin was evaluated by batch equilibrium method for specific metal ions viz. Fe3+, Co 2+, Ni2+, Cu2+, Zn2+, and Pb 2+. The study was extended to three variations such as evaluation of metal ion uptake in presence of various electrolytes in different concentrations, evaluation of the distribution of metal ion uptake at different pH ranges and evaluation of the rate of metal ion uptake at different time intervals. The adsorption isotherm was evaluated by means of Langmuir and Freundlich isotherm models. The order of the kinetics was also determined and the resin follows first order kinetics which shows that physisorption may be involved in the ion-exchange process. From the results, it was observed that the terpolymer resin acts as an excellent cation-exchanger. Compared to the commercially available phenolic and polystyrene resins, the synthesized terpolymer resin showed an excellent ion-exchange capacity with the selected metal ions. © 2013 Elsevier B.V. All rights reserved.

Gahlot S.,Indian Central Salt and Marine Chemicals Research Institute | Kulshrestha V.,Indian Central Salt and Marine Chemicals Research Institute | Kulshrestha V.,CSIR - Central Electrochemical Research Institute
ACS Applied Materials and Interfaces | Year: 2015

Nanohybrid membranes of electrically aligned functionalized carbon nanotube f CNT with sulfonated poly ether ether ketone (SPEEK) have been successfully prepared by solution casting. Functionalization of CNTs was done through a carboxylation and sulfonation route. Further, a constant electric field (500 V·cm-2) has been applied to align CNTs in the same direction during the membrane drying process. All the membranes are characterized chemically, thermally, and mechanically by the means of FTIR, DSC, DMA, UTM, SEM, TEM, and AFM techniques. Intermolecular interactions between the components in hybrid membranes are established by FTIR. Physicochemical measurements were done to analyze membrane stability. Membranes are evaluated for proton conductivity (30-90 °C) and methanol crossover resistance to reveal their potential for direct methanol fuel cell application. Incorporation of f CNT reasonably increases the ion-exchange capacity, water retention, and proton conductivity while it reduces the methanol permeability. The maximum proton conductivity has been found in the S-sCNT-5 nanohybrid PEM with higher methanol crossover resistance. The prepared membranes can be also used for electrode material for fuel cells and batteries. © 2014 American Chemical Society.

Ramachandra Murthy A.,CSIR - Central Electrochemical Research Institute | Karihaloo B.L.,University of Cardiff | Iyer N.R.,CSIR - Central Electrochemical Research Institute | Raghu Prasad B.K.,Indian Institute of Science
Cement and Concrete Research | Year: 2013

The RILEM work-of-fracture method for measuring the specific fracture energy of concrete from notched three-point bend specimens is still the most common method used throughout the world, despite the fact that the specific fracture energy so measured is known to vary with the size and shape of the test specimen. The reasons for this variation have also been known for nearly two decades, and two methods have been proposed in the literature to correct the measured size-dependent specific fracture energy (Gf) in order to obtain a size-independent value (GF). It has also been proved recently, on the basis of a limited set of results on a single concrete mix with a compressive strength of 37 MPa, that when the size-dependent Gf measured by the RILEM method is corrected following either of these two methods, the resulting specific fracture energy GF is very nearly the same and independent of the size of the specimen. In this paper, we will provide further evidence in support of this important conclusion using extensive independent test results of three different concrete mixes ranging in compressive strength from 57 to 122 MPa. © 2013 Elsevier Ltd. All rights reserved.

Karihaloo B.L.,University of Cardiff | Murthy A.R.,CSIR - Central Electrochemical Research Institute | Iyer N.R.,CSIR - Central Electrochemical Research Institute
Cement and Concrete Research | Year: 2013

The methods proposed by Elices and co-workers [1-3] and by Hu and Wittmann [4] are commonly used to determine the size-independent specific fracture energy (GF) of concrete by correcting the size-dependent specific fracture energy (Gf) measured by the RILEM work-of-fracture method. In the boundary effect model of Hu and Wittmann [4], the change in the local fracture energy (gf) is approximated by a bilinear function, whereas the method of Elices et al. [1] consists in determining the non-measured work-of-fracture by adjusting the tail of the P-δ curve that corresponds to the final part of the test. Acoustic emission (AE) experiments on notched specimens (Muralidhara et al. [5,6]) have revealed that under loading the AE events follow approximately a tri-linear distribution; initially the number of events increases almost linearly reaching an extended plateau when the number of events remains nearly constant and eventually the number reduces as the crack approaches the back stress free boundary of the specimen, reminiscent of the development of R-curve in a finite size specimen. This paper exploits this observation and proposes a tri-linear model for the determination of the size-independent specific fracture energy for three different concrete mixes ranging in compressive strength from 57 to 122 MPa. Remarkably, it is found that the resulting size-independent specific fracture energy GF determined by this tri-linear model and by the bi-linear model of Hu and Wittmann [4] is very nearly the same and independent of the size of the specimen. © 2013 Elsevier Ltd.

Bandyopadhyay S.,Indian Institute of Toxicology Research | Tfelt-Hansen J.,Copenhagen University | Chattopadhyay N.,CSIR - Central Electrochemical Research Institute
Journal of Neuroscience Research | Year: 2010

The G-protein-coupled calcium-sensing receptor (CaSR), upon activation by Ca2+ or other physiologically relevant polycationic molecules, performs diverse functions in the brain. The CaSR is widely expressed in the central nervous system (CNS) and is characterized by a robust increase in its expression during postnatal brain development over adult levels throughout the CNS. Developmental increases in CaSR levels in brain correlate with myelinogenesis. Indeed, neural stem cells differentiating to the oligodendrocyte lineage exhibit the highest CaSR expression compared with those differentiating to astrocytic or neuronal lineages. In adult CNS, CaSR has broad relevance in maintaining local ionic homeostasis. CaSR shares an evolutionary relationship with the metabotropic glutamate receptor and forms heteromeric complexes with the type B-aminobutyric acid receptor subunits that affects its cell surface expression, activation, signaling, and functions. In normal physiology as well as in pathologic conditions, CaSR is activated by signals arising from mineral ions, amino acids, polyamines, glutathione, and amyloid-β in conjunction with Ca2+1 and other divalent cationic ligands. CaSR activation regulates membrane excitability of neurons and glia and affects myelination, olfactory and gustatory signal integration, axonal and dendritic growth, and gonadotrophin-releasing hormonalneuronal migration. Insofar as the CaSR is a clinically important therapeutic target for parathyroid disorders, development of its agonists or antagonists as therapeutics for CNS disorder could be a major breakthrough. © 2010 Wiley-Liss, Inc.

Ahamed M.A.R.,Oxford Engineering College | Jeyakumar D.,CSIR - Central Electrochemical Research Institute | Burkanudeen A.R.,Jamal Mohamed College
Journal of Hazardous Materials | Year: 2013

2-Amino-6-nitro-benzothiazole and thiosemicarbazide with formaldehyde (BTF) terpolymer was synthesized by the condensation polymerization technique. The elemental analysis and physico-chemical parameters of the terpolymer were measured. This chelation terpolymer was characterized by infrared, electronic and nuclear magnetic resonance (1H & 13C NMR) spectral studies. The molecular weight of the terpolymer was determined by gel permeation chromatography (GPC). Surface analysis of the terpolymer was analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD) method. The thermal stability of the terpolymer was analyzed by thermogravimetric analysis (TGA). The cation-exchange property of the terpolymer was determined by batch equilibrium method with the effect of pH, contact time and electrolytes. The reusability of the resin was also studied to estimate the effectiveness of the terpolymer resin. © 2013 Elsevier B.V.

Caldwell W.B.,Stanford University | Klemperer S.L.,Stanford University | Lawrence J.F.,Stanford University | Rai S.S.,National Geophysical Research Institute | Ashish,CSIR - Central Electrochemical Research Institute
Earth and Planetary Science Letters | Year: 2013

We use common conversion point (CCP) stacking of Ps receiver functions to image the crustal structure and Moho of the Garhwal Himalaya of India. Our seismic array of 21 broadband seismometers spanned the Himalayan thrust wedge at 79-80°E, between the Main Frontal Thrust and the South Tibet Detachment, in 2005-2006. Our CCP image shows the Main Himalayan Thrust (MHT), the detachment at the base of the Himalayan thrust wedge, with a flat-ramp-flat geometry. Seismic impedance contrasts inferred from geologic cross-sections in Garhwal imply a negative impedance contrast (velocity decreasing downward) for the upper flat, located beneath the Lower Himalaya, and a positive impedance contrast (velocity increasing downward) for the ramp, located beneath the surface trace of the Munsiari Thrust (or MCT-I). At the lower flat, located beneath the Higher Himalaya, spatially coincident measurements of very high electrical conductivities require the presence of free fluids, and we infer a negative impedance contrast on the MHT caused by ponding of these fluids beneath the detachment. Our seismic image indicates that the upper flat of the MHT is ~10 km below sea level and dips north at ~2 ° , connecting to a mid-crustal ramp which is ~10 km high and dips at ~16 ° The lower flat is 20-25. km below sea level and dips at ~4 ° The Main Central Thrust (MCT) appears as a negative impedance contrast, dipping at ~16 ° The Moho is nearly horizontal at 35-45. km depth beneath the Sub-Himalaya and Lower Himalaya, deepening to 50. km or more beneath the Higher Himalaya. This depth is 10-25. km shallower than in the NW Indian Himalaya and 5-10. km shallower than in central Nepal, requiring significant along-strike variations in crustal thickness. The observed thickness of subducted Indian crust in Garwhal is 20-28. km. © 2013 Elsevier B.V.

Park D.M.,University of Wisconsin - Madison | Park D.M.,Lawrence Livermore National Laboratory | Akhtar M.S.,University of Wisconsin - Madison | Akhtar M.S.,CSIR - Central Electrochemical Research Institute | And 3 more authors.
PLoS Genetics | Year: 2013

Despite the importance of maintaining redox homeostasis for cellular viability, how cells control redox balance globally is poorly understood. Here we provide new mechanistic insight into how the balance between reduced and oxidized electron carriers is regulated at the level of gene expression by mapping the regulon of the response regulator ArcA from Escherichia coli, which responds to the quinone/quinol redox couple via its membrane-bound sensor kinase, ArcB. Our genome-wide analysis reveals that ArcA reprograms metabolism under anaerobic conditions such that carbon oxidation pathways that recycle redox carriers via respiration are transcriptionally repressed by ArcA. We propose that this strategy favors use of catabolic pathways that recycle redox carriers via fermentation akin to lactate production in mammalian cells. Unexpectedly, bioinformatic analysis of the sequences bound by ArcA in ChIP-seq revealed that most ArcA binding sites contain additional direct repeat elements beyond the two required for binding an ArcA dimer. DNase I footprinting assays suggest that non-canonical arrangements of cis-regulatory modules dictate both the length and concentration-sensitive occupancy of DNA sites. We propose that this plasticity in ArcA binding site architecture provides both an efficient means of encoding binding sites for ArcA, σ70-RNAP and perhaps other transcription factors within the same narrow sequence space and an effective mechanism for global control of carbon metabolism to maintain redox homeostasis. © 2013 Park et al.

Nithiyanantham U.,CSIR - Central Electrochemical Research Institute | Ramadoss A.,Jeju National University | Kundu S.,CSIR - Central Electrochemical Research Institute
RSC Advances | Year: 2014

Shape-selective TiO2 nanomaterials with different morphology, namely wire-like, flake-like and flower-like, have been synthesized by utilizing a simple wet chemical route by the reaction of titanium isopropoxide with ethanol and water mixture in the presence of cetyltrimethylammonium bromide. The shape of the particles can be easily tuned by altering the concentration of surfactant relative to the metal salt and changing the other reaction parameters. The formation mechanism of different shapes has been elaborated in detail. The shape-selective TiO2 nanomaterials have been utilized for electrochemical supercapacitor and DSSC applications. It was observed that TiO2 nanomaterials with various shapes showed different specific capacitance (Cs) values, and the order of Cs values is as follows: wire-like > flower-like > flake-like. The highest Cs of 3.16 F g-1 and better cycling stability was observed for TiO 2 nanomaterials having wire-like shapes. At a high scan rate 150 mV s-1, the capacitance retention of wire-like TiO2 electrode remains at about 90% after 5000 cycles. DSSC study results show that all the differently shaped TiO2 nanomaterials can be used as potential anode materials, and, among the different shapes, the flower-like morphology shows better photo-conversion efficiency. The presented synthesis process is fast, cost-effective and environmentally friendly and could be utilized for other applications like gas sensors, photo-catalysts or elimination of pollutants from contaminated soils. © 2014 the Partner Organisations.

Bajpai S.K.,Polymer Research Laboratory | Chand N.,CSIR - Central Electrochemical Research Institute | Chaurasia V.,Polymer Research Laboratory
Journal of Applied Polymer Science | Year: 2010

This study is focused on the investigation of moisture uptake properties of chitosan films. The GAB isotherm model is found to fit well to the experimental moisture uptake data obtained at 10, 25, and 37°C. The water vapor permeability is found to increase with temperature. The use of plasticizer enhances the water vapor permeability. Finally, the films have been loaded with ZnO nanoparticles and characterized by X-ray diffraction, differential scanning calorimetry, surface plasma resonance, and scanning electron microscopic analyses. The crystal size as determined using Scherrer's equation is found to be around 15 nm. The films have shown excellent antibacterial action against the model bacterium Escherichia coli. © 2009 Wiley Periodicals, Inc.

Nithiyanantham U.,CSIR - Central Electrochemical Research Institute | Ramadoss A.,Jeju National University | Ede S.R.,CSIR - Central Electrochemical Research Institute | Kundu S.,CSIR - Central Electrochemical Research Institute
Nanoscale | Year: 2014

A new route for the formation of wire-like clusters of TiO2 nanomaterials self-assembled in DNA scaffold within an hour of reaction time is reported. TiO2 nanomaterials are synthesized by the reaction of titanium-isopropoxide with ethanol and water in the presence of DNA under continuous stirring and heating at 60°C. The individual size of the TiO 2 NPs self-assembled in DNA and the diameter of the wires can be tuned by controlling the DNA to Ti-salt molar ratios and other reaction parameters. The eventual diameter of the individual particles varies between 15 ± 5 nm ranges, whereas the length of the nanowires varies in the 2-3 μm range. The synthesized wire-like DNA-TiO2 nanomaterials are excellent materials for electrochemical supercapacitor and DSSC applications. From the electrochemical supercapacitor experiment, it was found that the TiO2 nanomaterials showed different specific capacitance (C s) values for the various nanowires, and the order of Cs values are as follows: wire-like clusters (small size) > wire-like clusters (large size). The highest Cs of 2.69 F g-1 was observed for TiO2 having wire-like structure with small sizes. The study of the long term cycling stability of wire-like clusters (small size) electrode were shown to be stable, retaining ca. 80% of the initial specific capacitance, even after 5000 cycles. The potentiality of the DNA-TiO2 nanomaterials was also tested in photo-voltaic applications and the observed efficiency was found higher in the case of wire-like TiO2 nanostructures with larger sizes compared to smaller sizes. In future, the described method can be extended for the synthesis of other oxide based materials on DNA scaffold and can be further used in other applications like sensors, Li-ion battery materials or treatment for environmental waste water. © 2014 the Partner Organisations.

Sharma A.L.,CSIR - Central Electrochemical Research Institute | Kumar K.,Government Degree College | Deep A.,CSIR - Central Electrochemical Research Institute
Sensors and Actuators, A: Physical | Year: 2013

Silicon (Si)-nanopolyaniline (PAni) conducting platform has been electrochemically developed for the sensitive sensing of ammonia. The nano PAni films are formed through the assembly of nano granules of the polymer. The average height of the film is in the range of 50 nm. The electrical conductivity of the Si-PAni is influenced in the presence of ammonia. The response of this conductometric sensor is almost linear within 5-50 ppm of ammonia. The response and the recovery times are observed to be 10 and 60 s, respectively for 10 ppm of ammonia. The response time of the sensor for other concentrations (viz. 20, 30, 40, 50 and 60 ppm ammonia) is also in the range of 10 ± 2 s. However, the recovery of the sensor takes slightly longer time (70 ± 3 s) in case of higher concentrations (≥40 ppm) of ammonia. © 2013 Elsevier B.V. All rights reserved.

Roy S.,CSIR - Central Electrochemical Research Institute | Chapman D.S.,University of Utah
Journal of Geophysical Research: Atmospheres | Year: 2012

Seventy-five borehole temperature-depth profiles in south India, located between 8 and 15N, are analyzed to infer past changes in surface ground temperature. Solutions for a linear surface temperature change indicate average warming of about 0.90.3C over the past 12725years at the 95% level of confidence for the entire data set, albeit with considerable geographic variability. Some sites in a restricted region exhibit surface ground temperature cooling during the last 50 to 100years while a number of other borehole sites show large surface warming amplitudes in the range 1-3C with onset times during the last few decades to less than a Century. Such rapid changes may represent effects of local land use changes superimposed on the long-term climate change. Results of borehole analysis do not support a latitude effect in climate change. A set of 28 meteorological surface air temperature (SAT) records, distributed in the three major climatic provinces (Interior Peninsula, West Coast and East Coast) in south India yield an average warming trend of 0.60.2C/100years over the period 1901-2006 for which records exist. Combined analysis of borehole temperatures and SAT data yields a long-term, pre-observational mean temperature (baseline) 0.60.1C lower than the 1961-1990 mean SAT. With an additional 0.35C of warming beyond the 1961-1990 mean, the total warming from the ∼1800 baseline is 0.95C. Given multiple uncertainties, we consider the 0.9C of warming from borehole temperature inversion and 0.95C of warming from the hybrid borehole temperature-SAT analysis to be consistent if significant warming occurred in the 19th Century, prior to the onset of SAT records. The present data set together with the set of 70 temperature profiles in India analyzed earlier constitute an extensive documentation of climatic warming for the low latitude region 0-20 N that was previously under-sampled in global geothermal climate change studies. Copyright 2012 by the American Geophysical Union.

Behera S.K.,CSIR - Central Electrochemical Research Institute | Srivastava P.,CSIR - Central Electrochemical Research Institute | Tripathi R.,Ministry of New and Renewable Energy | Singh J.P.,Ministry of New and Renewable Energy | Singh N.,CSIR - Central Electrochemical Research Institute
Biomass and Bioenergy | Year: 2010

Jatropha curcas L., a multipurpose, drought resistant, perennial plant belonging to Euphorbiaceae family has gained lot of importance for the production of biodiesel. The properties of the crop and its oil have persuaded investors, policy makers and clean development mechanism (CDM) project developers to consider Jatropha as a substitute for fossil fuels to reduce greenhouse gas emissions. However, basic agronomic properties of Jatropha are not thoroughly understood and the environmental effects have not been investigated yet. Grey literature reports are very optimistic on simultaneous wasteland reclamation capability and oil yields. Studies were undertaken at Solar Energy Centre, Gurgaon, India to evaluate the plant performance under different agro-practices with special reference to irrigation scheduling, VAM and biofertilizers' applications, plant spacing, pruning trials for maximizing tree architecture and higher biomass. Parallel experiments were undertaken to understand the scope of J. curcas for intercropping practices in the under storey of dominating monoculture tree stands (Prosopis, Acacia and Neem). © 2009 Elsevier Ltd. All rights reserved.

Hazarika N.,CSIR - Central Electrochemical Research Institute | Baishya G.,CSIR - Central Electrochemical Research Institute
European Journal of Organic Chemistry | Year: 2014

The first example of the direct conversion of benzaldehydes into their corresponding N-tert-butyl amides through a Schmidt reaction/Ritter reaction sequence is described. A reagent mixture consisting of NaN3 and HBF4•OEt2 in acetic acid efficiently reacts with aromatic and conjugated (α,β-unsaturated) aldehydes to produce nitrile derivatives, which in situ undergo a Ritter reaction with tert-butyl acetate to afford the corresponding N-tert-butyl amides in almost quantitative yields. The method needs no column chromatography purification. The wide substrate scope as well as the ready availability of the reagent system also make this protocol convenient. © 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Mandal P.K.,CSIR - Central Electrochemical Research Institute
Beilstein Journal of Organic Chemistry | Year: 2014

The pentasaccharide repeating unit of the O-antigen of E. coli O117:K98:H4 strain has been synthesized using a combination of sequential glycosylations and [3 + 2] block synthetic strategy from the suitably protected monosaccharide intermediates. Thioglycosides and glycosyl trichloroacetimidate derivatives have been used as glycosyl donors in the glycosylations. © 2014 Mandal; licensee Beilstein-Institut. License and terms: see end of document.

Basu A.,CSIR - Central Electrochemical Research Institute | Kumar G.S.,CSIR - Central Electrochemical Research Institute
International Journal of Biological Macromolecules | Year: 2013

The interaction of the dietary pigment curcumin with herring testes deoxyribonucleic acid was studied by biophysical and microcalorimetric techniques. Curcumin bound to DNA exhibiting hypochromic effect in absorbance and enhanced intensity of its fluorescence. The binding a affinity value evaluated from spectroscopy data was of the order 104M-1. The quantum efficiency value testified the occurrence of energy transfer from the DNA base pairs to the curcumin molecules. Displacement studies of DNA bound DAPI, Hoechst and ethidium bromide suggested binding of curcumin to be in the minor groove of the DNA. Moderate conformational perturbations of the B-form structure of DNA occurred on binding. The binding affinity weakened as the DNA GC content enhanced. The binding was characterized by negative enthalpy and positive entropy changes; the binding affinity from calorimetry was in good agreement with that evaluated from the spectral data. The binding was dominated by hydrophobic and other non-polyelectrolytic forces; the polyelectrolytic forces contributing only a quarter to the total Gibbs energy at 50mM [Na+]. © 2013 Elsevier B.V.

Kumar S.,CSIR - Central Electrochemical Research Institute
Annals of Library and Information Studies | Year: 2016

The study examines the conformity of Lotka’s law to authorship distribution in the field of Artificial Neural Networks research (ANNs) in India during 1991–2014 using Science Citation Index-Expanded. There were 3411 articles contributed by 5654 unique authors. Lotka’s law was tested using methodology suggested by Pao and compared with maximum likelihood method advocated by Nicholls. The main elements involved in fitting in Lotka’s law were identified. These includes criterion for taking a certain pair of observed data points for calculating Lotka’s gradient, the constant for measurement of single author productivity and assessing goodness-of-fit. The results suggested that author productivity distribution, predicted by the modified Lotka’s Law suggested by Pao, was confirmed to the ANNs discipline in India whereas methodology suggested by Nicholls was not able to explain the author productivity distribution for the same. Evaluation of the prolific authors indicated that most of them are among the top position in their respective institutions. However, they were not listed as first author in their publications supporting that all the authors should be considered while analysing author productivity. © 2016, National Institute of Science Communication and Information Resources (NISCAIR). All rights reserved.

Lakshmi J.,CSIR - Central Electrochemical Research Institute | Vasudevan S.,CSIR - Central Electrochemical Research Institute
Environmental Science and Pollution Research | Year: 2013

A batch adsorption process was applied to investigate the removal of perchlorate (ClO4 -) from water by graphene. In doing so, the thermodynamic adsorption isotherm and kinetic studies were also carried out. Graphene was prepared by a facile liquid-phase exfoliation. Graphene was characterized by Raman spectroscopy, Fourier-transform infrared spectroscopy, powder X-ray diffraction, scanning electron microscope, and zeta potential measurements. A systematic study of the adsorption process was performed by varying pH, ionic strength, and temperature. The adsorption efficiency of graphene was 99.2 %, suggesting that graphene is an excellent adsorbent for ClO4 - removal from water. The rate constants for all these kinetic models were calculated, and the results indicate that second-order kinetics model was well suitable to model the kinetic adsorption of ClO4 -. Equilibrium data were well described by the typical Langmuir adsorption isotherm. The experimental results showed that graphene is an excellent perchlorate adsorbent with an adsorbent capacity of up to 0.024 mg/g at initial perchlorate concentration of 2 mg/L and temperature of 298 K. Thermodynamic studies revealed that the adsorption reaction was a spontaneous and endothermic process. Graphene removed the perchlorate present in the water and reduced it to a permissible level making it drinkable. © 2013 Springer-Verlag Berlin Heidelberg.

Adarsh N.,Indian National Institute for Interdisciplinary Science and Technology | Krishnan M.S.,Indian National Institute for Interdisciplinary Science and Technology | Ramaiah D.,Indian National Institute for Interdisciplinary Science and Technology | Ramaiah D.,CSIR - Central Electrochemical Research Institute
Analytical Chemistry | Year: 2014

With an objective to develop optical probes for biologically important anions and neutral molecules, we synthesized three novel NIR absorbing aza-BODIPY derivatives, 3a?3c, and have systematically tuned their photophysical properties by changing the peripheral substitution. A profound red-shift was observed in the absorption and fluorescence spectra of the aza-BODIPY dyes with the change in substitution from azido (3a) to amino (3b) to dimethylamino (3c) groups. Theoretical calculations of 3a? 3c showed a consistent decrease in bandgap, which supports the observed spectral changes. The study of their interactions with various analytes revealed that the azido-aza-BODIPY 3a selectively interacts with hydrogen sulfide (H2S) when compared to other molecules. Uniquely, the detection of H2S can be visualized through a change in color from bright blue to purple with a detection limit of 0.5 ppm. The sensitivity of the probe was observed to be ∼20-fold higher than the allowed exposure limits of H2S as defined by EPA (10 ppm). The aza-BODIPY derivative 3b, on the other hand, exhibited selective interactions with nitrite ions (NO2 ?) and nitric oxide (NO) in aqueous medium through a visible color change from blue to green with a sensitivity of 20 and 0.15 ppb, respectively. In contrast, the dimethylamino-aza-BODIPY derivative, 3c, showed negligible affinity for the anions and neutral molecules tested. By tuning the photophysical properties through the judicious functionalization, the aza-BODIPY dyes thus synthesized can be utilized for the sensitive on-site detection and analysis of H2S, NO2 ?, and NO in the aqueous medium. © 2014 American Chemical Society.

Rao C.N.R.,CSIR - Central Electrochemical Research Institute
Chimia | Year: 2012

Single-layer graphene (SLG), the 3.4 Å thick two-dimensional sheet of sp2 carbon atoms, was first prepared in 2004 by mechanical exfoliation of graphite crystals using the scotch tape technique. Since then, SLG has been prepared by other physical methods such as laser irradiation or ultrasonication of graphite in liquid media. Chemical methods of synthesis of SLG are more commonly used; the most popular involves preparation of single-layer graphene oxide followed by reduction with a stable reagent, often assisted by microwave heating. This method yields single-layer reduced graphene oxide. Other methods for preparing SLG include chemical vapour deposition over surfaces of transition metals such as Ni and Cu. Large-area SLG has also been prepared by epitaxial growth over SiC. Few-layer graphene (FLG) is prepared by several methods; arc discharge of graphite in hydrogen atmosphere being the most convenient. Several other methods for preparing FLG include exfoliation of graphite oxide by rapid heating, ultrasonication or laser irradiation of graphite in liquid media, reduction of few-layer graphene oxide, alkali metal intercalation followed by exfoliation. Graphene nanoribbons, which are rectangular strips of graphene, are best prepared by the unzipping of carbon nanotubes by chemical oxidation or laser irradiation. Many graphene analogues of inorganic materials such as MoS2, MoSe2 and BN have been prepared by mechanical exfoliation, ultrasonication and by chemical methods involving high-temperature or hydrothermal reactions and intercalation of alkali metals followed by exfoliation. Scrolls of graphene are prepared by potassium intercalation in graphite or by microwave irradiation of graphite immersed in liquid nitrogen. © Schweizerische Chemische Gesellschaft.

Bhattacharya D.,CSIR - Central Electrochemical Research Institute
European Journal of Inorganic Chemistry | Year: 2014

A new N,O-bischelator-bridged dirhenium(I) metallacycle, [Re 2(CO)6(μ-η4-mpdo)(μ-4,4-tmdp)] (1, H2mpdo = 2-methylpyrimidine-4,6-diol, 4,4-trimethylenedipyridine) has been self-assembled in a one-pot reaction in p-xylene at 140 C. Compound 1 displays unusual multiple phosphorescence emissions at room temperature; an emission quantum yield of 0.26 ± 0.03 and triexponential decay with an average radiative decay constant of 0.052 μs (λmax = 342 nm) were determined. These results as well as those of DFT/TDDFT calculations confirmed the nature of the emitting states. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Gogoi J.,CSIR - Central Electrochemical Research Institute | Gogoi P.,CSIR - Central Electrochemical Research Institute | Boruah R.C.,CSIR - Central Electrochemical Research Institute
European Journal of Organic Chemistry | Year: 2014

A series of steroidal and non-steroidal β-ketoenamides have been synthesized from their corresponding β-halo α,β-unsaturated aldehydes. This synthetic methodology provides efficient access to (Z)-β-ketoenamides. The structures of these products have been unambiguously established by single crystal XRD studies. This process is found to be mild and inexpensive. The required β-halo α,β-unsaturated aldehydes are synthesized from corresponding ketones using the Vilsmeier formylation reaction. One of the prepared β-ketoenamides was transformed into its corresponding 2-aminodihydroisoquinoline derivative. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Maheswari S.,CSIR - Central Electrochemical Research Institute | Sridhar P.,CSIR - Central Electrochemical Research Institute | Pitchumani S.,CSIR - Central Electrochemical Research Institute
Electrocatalysis | Year: 2012

Carbon-supported silver in varying percentage viz. 40%, 60%, and 80% (Ag/C) is prepared by sodium citrate protecting method. The structure, dispersion, electrochemical characterization, and surface area and oxygen reduction reaction pathway of Ag/C are determined by XRD, TEM, CV, and LSV, respectively. The catalyst is evaluated for its electrocatalytic activity towards oxygen reduction reaction (ORR) in alkaline polymer electrolyte membrane fuel cells (APEMFCs); 60% Ag/C gives higher performance than 40%, and 80% Ag/C. Metal loading on cathode is optimized through the cell polarization studies using 60% Ag/C. A peak power density of 10 mW/cm 2 is obtained for APEMFC single cell comprising 60% Ag/C and 38% Pt/C as cathode and anode catalysts, respectively. © 2011 Springer Science+Business Media, LLC.

Dhathathreyan A.,CSIR - Central Electrochemical Research Institute
Journal of Physical Chemistry B | Year: 2011

In this work, we demonstrate the activity of enzyme invertase immobilized in the pores of nanoporous anodized 3 ?m thick aluminum oxide (AA). The porous anodic alumina has uniform nanosized pores with an interpore distance of p = 100 nm, with pore diameters on the order of 60-65 nm. The pores trap the enzyme and continuous monitoring of the activity is carried out in a flow cell where the substrate is made to flow and the product is detected. The activity of the immobilized enzyme has been determined for the different concentrations of sucrose and for pH ranging from 3 to 6.5. Maximum activity was found for pH 4.5. Adsorption of the enzyme followed by its interaction with the substrate have been analyzed using confocal laser scanning microscopy (CLSM) and surface plasmon spectroscopy (SPR) and the results obtained show excellent correlation. SPR results show a biphasic kinetics for the adsorption of the enzyme as well as its interaction with the substrate with rates of adsorption for the enzyme at k = 2.9-105M-1 s-1 and 1.17-105M-1 s-1. The rate of interaction of the substrate with the invertase is initially rapid with k = 4.49 - 105 M-1 s-1 followed by a slower rate 1.43 - 104 M-11. © 2011 American Chemical Society.

Mittala R.,CSIR - Central Electrochemical Research Institute
Annals of Library and Information Studies | Year: 2016

The paper discusses the steps taken for the system migration from DOS based CDS/ISIS to Windows Server platform. A web based system has been developed using SQL Server 2005 as backend and asp.net 3.5 Microsoft Technology as front end. The unique feature of the developed system is compatibility with web and Desktop Publishing (DTP) which makes it more useful. A brief description and need for the system migration/ development are discussed. © 2016, National Institute of Science Communication and Information Resources (NISCAIR). All rights reserved.

Singh M.,CSIR - Central Electrochemical Research Institute | Singh P.K.,CSIR - Central Electrochemical Research Institute | Misra-Bhattacharya S.,CSIR - Central Electrochemical Research Institute
Journal of Biotechnology | Year: 2012

The DExD/H box families of RNA helicases are a multifunctional group of proteins involved in unwinding of inter- and intra-molecular base-paired regions. Successful knockdown of DEAD box RNA helicase gene (BmL3-Helicase) of human lymphatic filarial parasite Brugia malayi was done with specifically designed and chemically synthesized siRNA of <20. bp to observe the role of enzyme in parasite biology and its worth as an antifilarial drug target. We made efforts to deliver siRNA into parasite by both electroporation and soaking that resulted into diminished helicase gene expression associated with decreased parasite motility, viability (97%) and release of microfilariae (81.0% reduction) from adult females in vitro. The specific gene knockdown also resulted into death of adult male worms in addition to phenotypic deformities in female worm intrauterine stages. RT-PCR of siRNA treated worms revealed a complete knockdown of BmL3-Helicase transcription within 16. h. The present findings thus illustrate that targeting helicase gene of B. malayi would not only interfere with embryogenesis and microfilarial production but also result into decreased motility and viability of microfilariae and adult parasites. The B. malayi helicase enzyme thus represents a possible antifilarial drug target. © 2011 Elsevier B.V..

Kumar N.,CSIR - Central Electrochemical Research Institute
Prosthetics and Orthotics International | Year: 2014

Background: Finite element analysis has been universally employed for the stress and strain analysis in lower extremity prosthetics. The socket adapter was the principal subject of interest due to its importance in deciding the knee motion range. Objectives: This article focused on the static and dynamic stress analysis of the designed hybrid adapter developed by the authors. A standard mechanical design validation approach using von Mises was followed. Four materials were considered for the analysis, namely, carbon fiber, oil-filled nylon, Al-6061, and mild steel. Study design: The paper analyses the static and dynamic stress on designed hybrid adapter which incorporates features of conventional male and female socket adapters. The finite element analysis was carried out for possible different angles of knee flexion simulating static and dynamic gait situation. Methods: Research was carried out on available design of socket adapter. Mechanical design of hybrid adapter was conceptualized and a CAD model was generated using Inventor modelling software. Static and dynamic stress analysis was carried out on different materials for optimization. Results: The finite element analysis was carried out on the software Autodesk Inventor Professional Ver. 2011. The peak value of von Mises stress occurred in the neck region of the adapter and in the lower face region at rod eye-adapter junction in static and dynamic analyses, respectively. Conclusions: Oil-filled nylon was found to be the best material among the four with respect to strength, weight, and cost. Copyright © 2013 The International Society for Prosthetics and Orthotics.

Prathap G.,CSIR - Central Electrochemical Research Institute
Journal of the American Society for Information Science and Technology | Year: 2014

The h-index, as originally proposed (Hirsch, 2005), is a purely heuristic construction. Burrell (2013) showed that efforts to derive formulae from the mathematical framework of Lotkaian informetrics could lead to misleading results. On this note, we argue that a simple heuristic " thermodynamical" model can enable a better three-dimensional (3D) evaluation of the information production process leading to what we call the zynergy-index. © 2013 ASIS&T.

Vasudevan S.,CSIR - Central Electrochemical Research Institute
Journal of Water Process Engineering | Year: 2014

The present study explores the removal of phenol from water by peroxi-electrocoagulation method using mild steel as anode and graphite as cathode. The various parameters like effect of pH, concentration of phenol, current density, temperature, and co-existing ions on the removal efficiency of phenol from the water was studied. These studies were carried out at an initial concentration of phenol of 2.5mg/L. The results showed that the maximum removal efficiency of 92% was achieved at a current density of 0.10A/dm2 and pH of 2.0. The results of pilot scale study show that the process was technologically feasible. © 2014 Elsevier Ltd.

Bera S.,CSIR - Central Electrochemical Research Institute | Panda G.,CSIR - Central Electrochemical Research Institute
ACS Combinatorial Science | Year: 2012

Diastereoselective trans-2,5-disubstituted amino acids derived diverse morpholines, piperazines and thiomorpholines were prepared in 30 min-1 h with high yields through iodine-mediated 6-exotrig type cyclization from a single common synthetic intermediate. The displacement of iodine with hydride ion gave a methyl substituent at the 2-position of morpholines which provides an additional opportunity for diversity oriented nucleophilic substitution on the rings as well as incorporation of substituents at the 5-position from amino acids constituents. © 2011 American Chemical Society.

Sashidhara K.V.,CSIR - Central Electrochemical Research Institute | Palnati G.R.,CSIR - Central Electrochemical Research Institute | Avula S.R.,CSIR - Central Electrochemical Research Institute | Kumar A.,CSIR - Central Electrochemical Research Institute
Synlett | Year: 2012

An efficient and general protocol for a rapid synthesis of different substituted 3-aryl coumarins is reported. A series of different substituted phenyl acetic acids have been successfully reacted with different substituted 2-hydroxy benzaldehydes in the presence of cyanuric chloride (2,4,6-trichloro-1,3,5-triazine) and N-methyl morpholine to afford 3-aryl coumarins in good to excellent yields. © Georg Thieme Verlag Stuttgart · New York.

Jalali S.,CSIR - Central Electrochemical Research Institute | Jayaraj G.G.,CSIR - Central Electrochemical Research Institute | Scaria V.,CSIR - Central Electrochemical Research Institute
Biology Direct | Year: 2012

Background: The availability of sequencing technology has enabled understanding of transcriptomes through genome-wide approaches including RNA-sequencing. Contrary to the previous assumption that large tracts of the eukaryotic genomes are not transcriptionally active, recent evidence from transcriptome sequencing approaches have revealed pervasive transcription in many genomes of higher eukaryotes. Many of these loci encode transcripts that have no obvious protein-coding potential and are designated as non-coding RNA (ncRNA). Non-coding RNAs are classified empirically as small and long non-coding RNAs based on the size of the functional RNAs. Each of these classes is further classified into functional subclasses. Although microRNAs (miRNA), one of the major subclass of ncRNAs, have been extensively studied for their roles in regulation of gene expression and involvement in a large number of patho-physiological processes, the functions of a large proportion of long non-coding RNAs (lncRNA) still remains elusive. We hypothesized that some lncRNAs could potentially be processed to small RNA and thus could have a dual regulatory output.Results: Integration of large-scale independent experimental datasets in public domain revealed that certain well studied lncRNAs harbor small RNA clusters. Expression analysis of the small RNA clusters in different tissue and cell types reveal that they are differentially regulated suggesting a regulated biogenesis mechanism.Conclusions: Our analysis suggests existence of a potentially novel pathway for lncRNA processing into small RNAs. Expression analysis, further suggests that this pathway is regulated. We argue that this evidence supports our hypothesis, though limitations of the datasets and analysis cannot completely rule out alternate possibilities. Further in-depth experimental verification of the observation could potentially reveal a novel pathway for biogenesis.Reviewers: This article was reviewed by Dr Rory Johnson (nominated by Fyodor Kondrashov), Dr Raya Khanin (nominated by Dr Yuriy Gusev) and Prof Neil Smalheiser. For full reviews, please go to the Reviewer's comment section. © 2012 Jalali et al.; licensee BioMed Central Ltd.

Jana A.,Indian Institute of Technology Kharagpur | Pahari P.,CSIR - Central Electrochemical Research Institute | Mal D.,Indian Institute of Technology Kharagpur
Synlett | Year: 2012

Anionic [4+2] annulation of lithiated furoindolones with dimethyl maleate followed by selective demethoxycarbonylation provides an efficient synthetic route to 3-methoxycarbonylcarbazoles. The route has led to the straightforward synthesis of two natural products, namely clausine E, mukonine, and their 4-prenyl analogues. A new route to cyclohepta[d,e,f]carbazole was also uncovered during the investigations. © 2012 Georg Thieme Verlag StuttgartNew York.

Banerjee S.,CSIR - Central Electrochemical Research Institute | Singh S.,CSIR - Central Electrochemical Research Institute | Rahman L.U.,CSIR - Central Electrochemical Research Institute
Biotechnology Advances | Year: 2012

Agrobacterium rhizogenes induced hairy root cultures are entering into a new juncture of functional research in generating pharmaceutical lead compounds by bringing about chemical transformations aided through its inherent enzyme resources. Rational utilization of hairy root cultures as highly effective biotransformation systems has come into existence in the last twenty years involving a wide range of plant systems as well as exogenous substrates and diverse chemical reactions. To date, hairy root cultures are preferred over plant cell/callus and suspension cultures as biocatalyst due to their genetic/biochemical stability, hormone-autotrophy, multi-enzyme biosynthetic potential mimicking that of the parent plants and relatively low-cost cultural requirements. The resultant biotransformed molecules, that are difficult to make by synthetic organic chemistry, can unearth notable practical efficacies by acquiring improved physico-chemical properties, bioavailability, lower toxicity and broader therapeutic properties. The present review summarizes the overall reported advances made in the area of hairy root mediated biotransformation of exogenous substrates with regard to their reaction types, plant systems associated, bacterial strains/molecules involved and final product recovery. © 2011 Elsevier Inc.

Chiliveri S.C.,CSIR - Central Electrochemical Research Institute | Deshmukh M.V.,CSIR - Central Electrochemical Research Institute
Biochemical Journal | Year: 2014

The association of RDE-4 (RNAi defective 4), a protein containing two dsRBDs (dsRNA-binding domains), with long dsRNA and Dcr-1 (Dicer1 homologue) initiates the siRNA pathway in Caenorhabditis elegans. Unlike its homologues in higher eukaryotes, RDE-4 dsRBDs possess weak (micromolar) affinity for short dsRNA. With increasing length of dsRNA, RDE-4 exhibits enhanced affinity due to co-operativity. The linker and dsRBD2 are indispensable for RDE-4's simultaneous interaction with dsRNA and Dcr-1. In the present study, we have determined the solution structures of RDE-4 constructs that contain both dsRBDs and the linker region. In addition to the canonical dsRBD fold, both dsRBDs of RDE-4 show modified structural features such as truncation in the ß1-ß2 loop that rationalize RDE-4's relatively weak dsRNA affinity. Structure and binding studies demonstrate that dsRBD2 plays a decisive role in the RDE-4-dsRNA interaction; however, in contrast with previous findings, we found ephemeral interaction of RDE-4 dsRBD1 with dsRNA. More importantly, mutations in two tandem lysine residues (Lys217 and Lys218) in dsRBD2 impair RDE-4's dsRNA-binding ability and could obliterate RNAi initiation in C. elegans. Additionally, we postulate a structural basis for the minimal requirement of linker and dsRBD2 for RDE-4's association with dsRNA and Dcr-1. © 2014 Biochemical Society.

Shil A.K.,CSIR - Central Electrochemical Research Institute | Das P.,CSIR - Central Electrochemical Research Institute
Green Chemistry | Year: 2013

Solid supported platinum(0) (SS-Pt) nanoparticles were developed as a heterogeneous catalyst following a reduction/deposition method and characterized by SEM, TEM, EDX and XRD analysis. The SS-Pt catalyst was applied in the chemo-selective reduction of nitroarenes to N-arylhydroxylamines using hydrazine hydrate as a hydrogen source. A wide variety of reducible functional groups such as halides, carboxylic acids, esters, amides, nitriles, keto, alkenes, alkynes and N-benzyl were well tolerated under the reaction conditions. This process was further successfully employed in 10 g scale reactions. N-Arylhydroxylamines were further applied for catalyst free synthesis of azoxybenzenes. Moreover, use of PEG-400 as cheap reaction medium, additive free methodology and the recyclability of SS-Pt catalyst up to ten times without significant loss of catalytic activity evidently follow the principles of green chemistry. © 2013 The Royal Society of Chemistry.

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.

Kumar S.,CSIR - Central Electrochemical Research Institute | Asif M.H.,CSIR - Central Electrochemical Research Institute | Chakrabarty D.,CSIR - Central Electrochemical Research Institute | Tripathi R.D.,CSIR - Central Electrochemical Research Institute | And 2 more authors.
Journal of Hazardous Materials | Year: 2013

Global industrial growth has contaminated the soil and water with many hazardous compounds, including heavy metals. These heavy metals are not only toxic to plants but also cause severe human health hazards when leach out into food chain. One of the approaches employed for the decontamination of environment includes identification and overexpression of genes involved in the detoxification mechanism of plants. Glutathione S-transferases (GSTs) are a superfamily of enzymes, principally known for their role in detoxification reactions. Different classes of GSTs have been used to develop plants with improved detoxification mechanism, but not much information is available for Lambda class of GSTs. Here, we studied expression of OsGSTLs in different rice genotypes under arsenic stress. The study suggests differential expression of these genes in arsenic sensitive and tolerant genotypes. Further, the role of one member of Lambda class OsGSTL2 was studied by expressing in heterologous system, Arabidopsis. Transgenic lines developed were analysed for their response to different abiotic stresses including heavy metals. Analysis suggests that OsGSTL2 provides tolerance for heavy metals and other abiotic stresses like cold, osmotic stress and salt. We conclude that OsGSTLs can be utilized for developing plant varieties tolerant to different abiotic stresses including heavy metals. © 2013 Elsevier B.V.

Kumar K.V.,CSIR - Central Electrochemical Research Institute | Patra D.D.,CSIR - Central Electrochemical Research Institute
Water, Air, and Soil Pollution | Year: 2013

pt?>Two cadmium- and nickel-resistant plant growth-promoting bacteria, Pseudomonas sp. ASSP 5 and ASSP 29, were isolated from fly ash-contaminated sites, and their plant growth promotion ability was tested by inoculating Lycopersicon esculentum plants grown in fly ash-amended soil. Parameters that were monitored included plant height, wet and dry weights, protein and chlorophyll content in leaves, and concentration of metals in plant root and shoot systems. Although both the bacterial isolates were effective, in most cases, ASSP 29 Pseudomonas sp. exerted a more pronounced effect on plant growth than did ASSP 5. The present observations also showed that both the strains ASSP 5 and ASSP 29 protect the plants against the inhibitory effect of nickel and cadmium, probably due to the production of indole acetic acid and siderophore, and solubilization of phosphate. © 2012 Springer Science+Business Media Dordrecht.

Kumar A.,CSIR - Central Electrochemical Research Institute | Saxena D.,CSIR - Central Electrochemical Research Institute | Gupta M.K.,CSIR - Central Electrochemical Research Institute
Green Chemistry | Year: 2013

The first ZnO-NP catalyzed Ugi type three-component (AB2C) reaction has been developed for the synthesis of 2-arylamino-2- phenylacetimidamide from an aldehyde, amine and isocyanide in aqueous media. This nanoparticle catalysed reaction (NPCR) is high yielding and has good atom economy as well as atom efficiency. The synthesized phenylacetimidamide yielded 2-amino-2-phenylacetamide on hydrolysis with I2-SDS-water, whereas alkaline hydrolysis afforded the N-substituted α-amino acid. This journal is © 2013 The Royal Society of Chemistry.

Tiwari P.,CSIR - Central Electrochemical Research Institute
Industrial Crops and Products | Year: 2016

Mentha arvensis L defines an important species of the genus Mentha, highlighting socio-economic and pharmacological importance. The plant species attributes its aromatic properties to the presence of essential oil rich in monoterpenes and sesquiterpenes and volatile constituents such as menthol, menthone, carvacol, pulgone and isomenthone, imparting characteristic mint flavor. The research on trichomes and essential oil biosynthesis has received considerable attention from scientific community owing to its pharmaceutical and economic benefits. Although, molecular and biochemical investigations have provided key insights into trichome-specific metabolic pathways and the corresponding genes, however the exact mechanism of action of the enzymes in various trichome developmental stages remains unreported. In an attempt to address the research on trichomes, the review article provides a comprehensive account of M. arvensis L, discussing its taxonomic distribution and cultivation to its commercial applications. Furthermore, genomic investigations on elucidation of essential oil biosynthetic pathway and the respective enzymes would provide a focused insight, opening new possibilities for genetic engineering and development of better varieties of Mentha with improved agro-economic traits. Such studies highlight good prospects of M. arvensis L in commercial applications, owing to its health benefits in aromatherapy and pharmacology. © 2015 Elsevier B.V.

Bala M.,CSIR - Central Electrochemical Research Institute | Verma P.K.,CSIR - Central Electrochemical Research Institute | Sharma U.,CSIR - Central Electrochemical Research Institute | Sharma U.,Indian Institute of Technology Bombay | And 2 more authors.
Green Chemistry | Year: 2013

An efficient and versatile iron phthalocyanine catalyzed method has been developed for N-alkylation of various amines with alcohols. Readily available alcohols were used as alkylating agents for direct N-alkylation of aminobenzothiazoles, aminopyridines and aminopyrimidines. N-Alkylation of ortho-substituted anilines (-NH2, -SH and -OH) led to the synthesis of 2-substituted benzimidazoles, benzothiazoles and benzoxazoles in one pot. © 2013 The Royal Society of Chemistry.

Haldar S.,CSIR - National Chemical Laboratory | Kolet S.P.,CSIR - National Chemical Laboratory | Thulasiram H.V.,CSIR - National Chemical Laboratory | Thulasiram H.V.,CSIR - Central Electrochemical Research Institute
Green Chemistry | Year: 2013

Basic limonoids carrying a 4,4,8-trimethyl-17-furanylsteroid skeleton are a class of triterpenoids and well-known for their insecticidal as well as a vast array of pharmacological activities. Rare and synthetically challenging 12β- and 17β-hydroxylation was achieved on the basic limonoid skeleton to produce a novel series of hydroxylated limonoids using fungi-mediated biocatalysis. The fungal system belonging to the genera of Mucor efficiently converted azadiradione, epoxyazadiradione, gedunin and their derivatives into corresponding 12β- and/or 17β-hydroxy derivatives. The position and stereochemistry of hydroxylation was determined by rigorous spectroscopic and crystallographic studies. This fungi-mediated stereo- and regio-selective hydroxylation process was highly efficient and mild enough to sustain chemically sensitive functional groups around the basic limonoid skeleton. Modifications of specific functional groups and variation in biocatalyst were shown to bring selectivity among 12β- or 17β-hydroxylation. © 2013 The Royal Society of Chemistry.

Ghantani V.C.,CSIR - National Chemical Laboratory | Ghantani V.C.,CSIR - Central Electrochemical Research Institute | Lomate S.T.,CSIR - National Chemical Laboratory | Dongare M.K.,CSIR - National Chemical Laboratory | And 2 more authors.
Green Chemistry | Year: 2013

A series of calcium hydroxyapatite (HAP) catalysts were synthesised with a Ca/P ratio ranging from 1.3 to 1.89 by a co-precipitation method that involved changing the pH of the calcium and phosphorous precursors. The physicochemical characterization by XRD, SEM, BET surface area and CO2 and NH 3-TPD techniques confirmed the hydroxyapatite formation. These HAP catalysts were used for the vapour phase dehydration of lactic acid to acrylic acid. The HAP catalyst with a Ca/P ratio of 1.3 was found to be the most efficient catalyst among the synthesised series, which gave 100% conversion of lactic acid and 60% selectivity towards acrylic acid at 375 °C when a 50% (w/w) aqueous solution of lactic acid was used. The higher selectivity towards acrylic acid has been correlated to the increased acidity and reduced basicity of the HAP catalyst with a Ca/P ratio of 1.3 compared to the other HAP catalysts. The catalyst was found to be very stable and no deactivation was observed even after 300 h of reaction time. In situ FTIR studies were performed for understanding the mechanistic aspects and showed the formation of calcium lactate as an intermediate species during the dehydration of lactic acid to acrylic acid. © 2013 The Royal Society of Chemistry.

Mahalakshmi S.,CSIR - Central Electrochemical Research Institute | Mahalakshmi S.,Osmania University | Sunayana M.R.,CSIR - Central Electrochemical Research Institute | Saisree L.,CSIR - Central Electrochemical Research Institute | Reddy M.,CSIR - Central Electrochemical Research Institute
Molecular Microbiology | Year: 2014

The outer membrane of Gram-negative bacteria is an asymmetric lipid bilayer consisting of an essential glycolipid lipopolysaccharide (LPS) in its outer leaflet and phospholipids in the inner leaflet. Here, we show that yciM, a gene encoding a tetratricopeptide repeat protein of unknown function, modulates LPS levels by negatively regulating the biosynthesis of lipid A, an essential constituent of LPS. Inactivation of yciM resulted in high LPS levels and cell death in Escherichia coli; recessive mutations in lpxA, lpxC or lpxD that lower the synthesis of lipid A, or a gain of function mutation in fabZ that increases the formation of membrane phospholipids, alleviated the yciM mutant phenotypes. A modest increase in YciM led to significant reduction of LPS and increased sensitivity to hydrophobic antibiotics. YciM was shown to regulate LPS by altering LpxC, an enzyme that catalyses the first committed step of lipid A biosynthesis. Regulation of LpxC by YciM was contingent on the presence of FtsH, an essential membrane-anchored protease known to degrade LpxC, suggesting that FtsH and YciM act in concert to regulate synthesis of lipid A. In summary, this study demonstrates an essential role for YciM in regulation of LPS biosynthesis in E.coli. © 2013 John Wiley & Sons Ltd.

Kumar A.,CSIR - Central Electrochemical Research Institute | Suman B.M.,CSIR - Central Electrochemical Research Institute
Building and Environment | Year: 2013

Better insulation having low thermal conductivity is a significant contributor for new construction and retrofitting existing buildings, when the emphasis is on energy efficiency. The objective of the study is to determine the impact of the thermal insulation materials in buildings enabling effective energy savings with minimal occupation of space. Although, the Energy Conservation Building Code (ECBC), India defines the prescriptive and mandatory requirements for the U-factor and R-value but the way to achieve these values is left to the designer and there is no published data on these values. To accomplish these objectives, the experiments for computation of thermal resistance and over all heat transfer coefficients have been carried out by measuring the thermal conductivity of the various types of materials available in the Indian market having different thicknesses by Automatic Guarded Hot Plate Apparatus. One hundred and twelve combinations of wall and roof sections have been computed and compared with different thicknesses of insulating materials for determining U-factor and R-value to satisfy ECBC requirements. The results of the study show that 50 mm thick Elastospray with conventional roof and wall satisfy the ECBC requirements whereas, other insulation materials require higher thickness to fulfill the recommended values. To validate the results, two prototype buildings are constructed at CSIR-CBRI campus; one with conventional burnt clay brick wall, reinforced cement concrete roof and 50 mm thick outside thermal insulation and the other without insulation. The results of the winter and summer season for six months are presented. © 2012 Elsevier Ltd.

Manglik A.,CSIR - Central Electrochemical Research Institute | Rai S.N.,CSIR - Central Electrochemical Research Institute | Singh V.S.,CSIR - Central Electrochemical Research Institute
Water Resources Management | Year: 2013

Mathematical models play a key role in assessing the future behavior of a groundwater system in response to various schemes of ground water resources development such as artificial recharging and in selecting an appropriate one out of many proposed schemes for its sustainable development. This paper presents an analytical solution of groundwater flow equation for unconfined, anisotropic, 2-D rectangular aquifer under the Boussinesq approximation to predict water table fluctuations in the aquifer in response to general time-varying intermittent recharge from multiple rectangular infiltration basins of different spatial dimensions. The horizontal anisotropy incorporated in the model is such that the principal axes of the hydraulic conductivity tensor are oriented parallel to the rectangular sides of the aquifer. The time-varying recharge rate is approximated by a series of line elements of different lengths and slopes depending on the nature of variation of recharge rate. The solution is obtained by using extended finite Fourier sine transform. Application of the solution is demonstrated with the help of synthetic examples. Numerical results of the analytical solutions are verified by comparison with the results obtained from MODFLOW. Numerical results indicate significant effect of anisotropy in hydraulic conductivity on the nature of water table variation. © 2012 Springer Science+Business Media B.V.

Rao C.N.R.,CSIR - Central Electrochemical Research Institute | Lingampalli S.R.,CSIR - Central Electrochemical Research Institute
Small | Year: 2016

Photosynthesis that occurs in plants involves both the oxidation of water and the reduction of carbon dioxide. Plants carry out these reactions with ease, by involving electron-transport chains. In this article, hydrogen generation by the reduction of water in the laboratory by using semiconductor nanostructures through artificial photosynthesis is examined. Dye-sensitized photochemical generation of hydrogen from water is also discussed. Hydrogen generation by these means has great technological relevance, since it is an environmentally friendly fuel. The way in which oxygen can be generated by the oxidation of water using metal oxide catalysts is also shown. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Amaravathy P.,Anna University | Sowndarya S.,CSIR - Central Leather Research Institute | Sathyanarayanan S.,CSIR - Central Electrochemical Research Institute | Rajendran N.,Anna University
Surface and Coatings Technology | Year: 2014

In recent years, magnesium alloys are considered as a new class of biodegradable alloys. Though they have several favourable properties, higher susceptibility to hydrogen evolution and corrosion have limited their applications in the biomedical field. Recently, several coatings have been developed to overcome their higher degradation rate. In this regard, a new attempt has been made to develop niobium oxide (Nb2O5) coating on magnesium alloys to increase the biocompatibility and reduce the corrosion rate. Phase structure, surface morphology and chemical composition of the coating have been studied by Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) Spectroscopy, X-ray Diffraction Analysis (XRD), Scanning Electron Microscopy (SEM) with Energy Dispersive X-ray (EDX) Spectroscopy and Transmission Electron Microscopy (TEM) analysis. The prepared coating possesses good bioactivity and hydrophilicity in Simulated Body Fluid (SBF). Corrosion rate and hydrogen evolution rate were enormously controlled and the coating possesses excellent bonding strength with the substrate. The higher cell attachment and cell growth with pseudopodia extensions were observed by controlling the release of magnesium ions into the surrounding body tissue. © 2014 Elsevier B.V.

Paul P.,CSIR - Central Electrochemical Research Institute | Kumar G.S.,CSIR - Central Electrochemical Research Institute
Journal of Hazardous Materials | Year: 2013

This study was designed to examine the toxic interaction of two phenothiazinium dyes thionine (TO) and toluidine blue O (TBO) with tRNAphe by spectroscopic and calorimetric techniques. While phenothiazinium dye complexation with DNA is known, their bindings to RNA are not fully investigated. The non cooperative binding of both the dyes to tRNA was revealed from absorbance and fluorescence studies. From absorption, steady-state emission, the effect of ferrocyanide ion-induced steady-state fluorescence quenching, circular dichroism, the mode of binding of these dyes into the tRNA helix has been substantiated to be principally by intercalative in nature. Both dyes enhanced the thermal stability of tRNA. Circular dichroism studies provided evidence for the structural perturbations associated with the tRNA structure with induction of optical activity in the CD inactive dye molecules. Results from isothermal titration calorimetry experiments suggested that the binding of both dyes was predominantly entropy driven with a smaller but favorable enthalpy term that increased with temperature. The binding was dependent on the Na+ concentration, but had a larger non-electrostatic contribution to the Gibbs energy. A small heat capacity value and the enthalpy-entropy compensation in the energetics of the interaction characterized the binding of the dyes to tRNA. This study confirms that the tRNAphe binding affinity is greater for TO compared to TBO. The utility of the present work lies in understanding the potential binding and consequent damage to tRNA by these toxic dyes in their development as therapeutic agents. © 2013 Elsevier B.V.

Wahajuddin,CSIR - Central Electrochemical Research Institute | Raju K.S.R.,CSIR - Central Electrochemical Research Institute | Singh S.P.,CSIR - Central Electrochemical Research Institute | Taneja I.,CSIR - Central Electrochemical Research Institute
Antimicrobial Agents and Chemotherapy | Year: 2014

In the quest to explore the reason for the low and variable bioavailability of lumefantrine, we investigated the possible role of P-glycoprotein (P-gp) in lumefantrine intestinal absorption. An in situ single-pass intestinal perfusion study in rats with the P-gp inhibitor verapamil or quinidine and an ATPase assay with human P-gp membranes indicated that lumefantrine is a substrate of P-gp which limits its intestinal absorption. To confirm these findings, an in vivo pharmacokinetic study was performed in rats. The oral administration of verapamil (10 mg/kg of body weight) along with lumefantrine caused a significant increase in its bioavailability with a concomitant decrease in clearance. The increase in bioavailability of lumefantrine could be due to inhibition of P-gp and/or cytochrome P450 3A in the intestine/liver by verapamil. However, in a rat intestinal microsomal stability study, lumefantrine was found to be resistant to oxidative metabolism. Further, an in situ permeation study clearly showed a significant role of P-gp in limiting the oral absorption of lumefantrine. Thus, the increase in lumefantrine bioavailability with verapamil is attributed in part to the P-gp-inhibitory ability of verapamil. In conclusion, lumefantrine is a substrate of P-gp, and active efflux by P-gp across the intestine partly contributed to the low/variable bioavailability of lumefantrine. © 2014, American Society for Microbiology.

Bansal A.R.,CSIR - Central Electrochemical Research Institute | Dimri V.P.,CSIR - Central Electrochemical Research Institute
Geophysical Prospecting | Year: 2014

Interpretation of magnetic data can be carried out either in the space or frequency domain. The interpretation in the frequency domain is computationally convenient because convolution becomes multiplication. The frequency domain approach assumes that the magnetic sources distribution has a random and uncorrelated distribution. This approach is modified to include random and fractal distribution of sources on the basis of borehole data. The physical properties of the rocks exhibit scaling behaviour which can be defined as P(k) = Ak-β, where P(k) is the power spectrum as a function of wave number (k), and A and β are the constant and scaling exponent, respectively. A white noise distribution corresponds to β = 0. The high resolution methods of power spectral estimation e.g. maximum entropy method and multi-taper method produce smooth spectra. Therefore, estimation of scaling exponents is more reliable. The values of β are found to be related to the lithology and heterogeneities in the crust. The modelling of magnetic data for scaling distribution of sources leads to an improved method of interpreting the magnetic data known as the scaling spectral method. The method has found applicability in estimating the basement depth, Curie depth and filtering of magnetic data. © 2013 European Association of Geoscientists & Engineers.

Krishnakumari V.,CSIR - Central Electrochemical Research Institute | Nagaraj R.,CSIR - Central Electrochemical Research Institute
Biophysical Chemistry | Year: 2015

Peptides spanning the C-terminal segment of bovine-β-defensin-2 (BNBD-2) rich in cationic amino acids, show antimicrobial activity. However, they exhibit considerably reduced activity at physiological concentration of NaCl. In the present study, we have investigated whether N-terminal acylation (acetylation and palmitoylation) of these peptides would result in improved antimicrobial activity. N-terminal palmitoylation though increased hydrophobicity of the peptides, did not enhance antimicrobial potency. However, antibacterial activity of these peptides was not attenuated by NaCl. Biophysical studies on the palmitoylated peptides have indicated that antibacterial activity in the presence of NaCl arises due to the ability of the peptides to interact with membranes more effectively. These peptides showed hemolytic activity which was attenuated considerably in the presence of serum and lipid vesicles. In defensin related peptides, fatty acylation would be a convenient way to generate analogs that are active in the presence of salt. © 2014 Elsevier B.V.

Mandal A.K.,CSIR - Central Electrochemical Research Institute | Pandey R.,CSIR - Central Electrochemical Research Institute | Jha V.,CSIR - Central Electrochemical Research Institute | Mukerji M.,CSIR - Central Electrochemical Research Institute
Nucleic Acids Research | Year: 2013

Non-coding RNAs from transposable elements of human genome are gaining prominence in modulating transcriptome dynamics. Alu elements, as exonized, edited and antisense components within same transcripts could create novel regulatory switches in response to different transcriptional cues. We provide the first evidence for cooccurrences of these events at transcriptome-wide scale through integrative analysis of data sets across diverse experimental platforms and tissues. This involved the following: (i) positional anchoring of Alu exonization events in the UTRs and CDS of 4663 transcript isoforms from RefSeq mRNAs and (ii) mapping on to them A→I editing events inferred from ∼7 million ESTs from dbEST and antisense transcripts identified from virtual serial analysis of gene expression tags represented in Cancer Genome Anatomy Project next-generation sequencing data sets across 20 tissues. We observed significant enrichment of these events in the 30UTR as well as positional preference within the embedded Alus. More than 300 genes had cooccurrence of all these events at the exon level and were significantly enriched in apoptosis and lysosomal processes. Further, we demonstrate functional evidence of such dynamic interactions between Alu-mediated events in a time series data from Integrated Personal Omics Profiling during recovery from a viral infection. Such 'single transcript-multiple fate' opportunity facilitated by Alu elements may modulate transcriptional response, especially during stress. © 2013 The Author(s).

Reddy G.S.,Arizona State University | Reddy G.S.,CSIR - Central Electrochemical Research Institute | Garcia-Pichel F.,Arizona State University
Journal of Microbiology | Year: 2015

A Gram-negative, aerobic, non spore-forming, non-motile, rod-shaped, yellow pigmented bacterium CP155-2T was isolated from a biological soil crusts sample collected in the Colorado plateau, USA and subjected to polyphasic taxonomic characterization. Strain CP155-2T contained summed feature 3 (C16:1ω5c/C16:1ω7c) and C18:1ω7c as major fatty acids and diphosphatidylglycerol (DPG) along with phosphatidylethanolamine (PE) and phosphatidylglycerol (PG) as major polar lipids. Based on these characteristics CP155-2T was assigned to the genus Pseudomonas. Phylogenetic analysis based on 16S rRNA gene sequence further confirmed the affiliation of CP155-2T to the genus Pseudomonas and showed a 16S rRNA gene sequence similarity of less than 98.7% with already described species of the genus. Pseudomonas luteola, Pseudomonas zeshuii, and Pseudomonas duriflava were identified as the closest species of the genus Pseudomonas with 16S rRNA gene sequence similarities of 98.7%, 98.6%, and 96.9%, respectively. The values for DNA¨CDNA relatedness between CP155-2T and Pseudomonas luteola and Pseudomonas zeshuii were 23% and 14% respectively a value below the 70% threshold value, indicating that strain CP155-2T belongs to a novel taxon of the genus Pseudomonas lineage. The novel taxon status was strengthened by a number of phenotypic differences wherein CP155-2T was positive for oxidase, negative for gelatin hydrolysis, could utilize D-cellobiose, D-raffinose, L-rhamnose, D-sorbitol but not L-aspartic acid and L-glutamic acid. Based on the collective differences strain CP155–2T exhibited, it was identified as a novel species and the name Pseudomonas asuensis sp. nov. was proposed. The type strain of Pseudomonas asuensis sp. nov. is CP155–2T (DSM 17866T =ATCC BAA-1264T =JCM13501T =KCTC 32484T). © 2015, The Microbiological Society of Korea and Springer-Verlag Berlin Heidelberg.

Guleria P.,CSIR - Central Electrochemical Research Institute | Yadav S.K.,CSIR - Central Electrochemical Research Institute
American Journal of Biochemistry and Molecular Biology | Year: 2013

Steviol glycosides are the major secondary metabolites synthesized through steviol glycoside biosynthesis pathway operating in the leaves of Stevia rebaudiana. Present article documents the structural analysis of enzymes specific to steviol glycoside biosynthesis pathway, kaurenoic acid-13 hydoxylase (KAH) and three UDP-glycosyltransferases (UGT85C2, UGT74G1 and UGT76G1). The in silico protein structure prediction server SWISS MODEL was used to predict and evaluate the models. The secondary structure data of predicted model for KAH was in accordance to that of cytochrome P450s suggesting its nativeness to the respective superfamily. Similarly, the secondary structure data of target UGTs also showed conservation with the structural information of glycosyltransferases superfamily. PROCHECK and QMEAN Z-score evaluations suggested that the models predicted for the 4 query enzymatic proteins were of good quality. In addition, Ligand binding site analysis and molecular docking analysis was carried out for the predicted models. The following data suggested a possibility of the presence of an alternate pathway for the synthesis of steviol glycosides. © 2013 Academic Journals Inc.

Kasana R.C.,CSIR - Central Electrochemical Research Institute
Critical Reviews in Microbiology | Year: 2010

Proteases are hydrolytic enzymes which catalyze the total hydrolysis of proteins in to amino acids. Although proteolytic enzymes can be obtained from animals and plants but microorganisms are the preferred source for industrial applications in view of scientific and economical advantage. Among various groups of microbes, psychrotrophs are ideal candidates for enzymes production keeping in mind that enzymes active at low temperature and stable under alkaline condition, in presence of oxidants and detergents are in large demand as laundry additive. The proteases from psychrotrophs also find application in environmental bioremediation, food and molecular biology. During the previous two decades, proteases from psychrotrophs have received increased attention because of their wide range of applications, but the full potential of psychrotrophic proteases has not been exploited. This review focuses attention on the present status of knowledge on the production, optimization, molecular characteristics, applications, substrate specificity, and crystal structure of psychrotrophic proteases. The review will help in making strategies for exploitation of psychrotrophic protease resources and improvement of enzymes to obtain more robust proteases of industrial and biotechnological significance. © 2010 Informa UK Ltd.

Paul R.,Rajiv Gandhi University | Prasad M.,CSIR - Central Electrochemical Research Institute | Sah N.K.,TNB College
Cancer Biology and Therapy | Year: 2011

Neem (Azadirachta indica), a member of the Meliaceae family, is a fast growing tropical evergreen tree with a highly branched and stout, solid stem. Because of its tremendous therapeutic, domestic, agricultural and ethnomedicinal significance, and its proximity with human culture and civilization, neem has been called "the wonder tree" and "nature's drug store." All parts of this tree, particularly the leaves, bark, seed-oil and their purified products are widely used for treatment of cancer. Over 60 different types of biochemicals including terpenoids and steroids have been purified from this plant. Pre-clinical research work done during the last decade has fine-tuned our understanding of the anticancer properties of the crude and purified products from this plant. The anticancer properties of the plant have been studied largely in terms of its preventive, protective, tumor-suppressive, immunomodulatory and apoptotic effects against various types of cancer and their molecular mechanisms. This review aims at scanning scattered literature on "the anticancer biology of A. indica," related toxicity problems and future perspectives. The cogent data on the anticancer biology of products from A. indica deserve multi-institutional clinical trials as early as possible. The prospects of relatively cheaper cancer drugs could then be brighter, particularly for the under-privileged cancer patients of the world. © 2011 Landes Bioscience.

Gupta S.,CSIR - Central Electrochemical Research Institute | Nishi,CSIR - Central Electrochemical Research Institute
Indian Journal of Medical Research | Year: 2011

Visceral leishmaniasis (VL) or kala-azar is a chronic protozoan infection in humans associated with significant global morbidity and mortality. The causative agent is a haemoflagellate protozoan Leishmania donovani, an obligate intracellular parasite that resides and multiplies within macrophages of the reticulo-endothelial system. Most of the existing anti-leishmanial drugs have serious side effects that limit their clinical application. As an alternate strategy, vaccination is also under experimental and clinical trials. The in vitro evaluation designed to facilitate rapid testing of a large number of drugs has been focussed on the promastigotes milt little attention on the clinically relevant parasite stage, amastigotes. Screening designed to closely reflect the situation in vivo is currently time consuming, laborious, and expensive, since it requires intracellular amastigotes and animal model. The ability to select transgenic Leishmania expressing reporter proteins, such as the green fluorescent proteins (GFP) or the luciferase opened up new possibilities for the development of drug screening models. Many experimental animal models like rodents, dogs and monkeys have been developed, each with specific features, but none accurately reproduces what happens in humans. Available in vitro and in vivo methodologies for antileishmanial drug screening and their respective advantages and disadvantages are reviewed.

Kumar S.,CSIR - Central Electrochemical Research Institute | Sharma S.,CSIR - Central Electrochemical Research Institute | Chattopadhyay S.K.,CSIR - Central Electrochemical Research Institute
Fitoterapia | Year: 2013

The diversity present in biological activities and the medicinal significance of natural products provide a renewed interest in the use of natural compounds and, more importantly, their role as a basis for drug development. Advancements in the field of natural product chemistry provide valuable information on Garcinia fruits which revealed the presence of biologically important secondary metabolites named as polyisoprenylated benzophenones (PIBs). They are mainly present in the genus Garcinia (Guttiferae) which occupies a prominent position in the history of natural products. Compared to the long history of medicinal uses and widespread research on Garcinia, the study of polyisoprenylated benzophenones was relatively limited. During recent years, these PIBs have been recognized as interesting and valuable biologically active secondary metabolites as many of the isolated polyisoprenylated benzophenones exhibited significant cytotoxic activity in in vitro and in vivo assay. During past decades, some promising advances had been achieved in understanding the chemistry and pharmacology of polyisoprenylated benzophenones. However, there has been not any systematic review on the ethnobotanical importance, chemistry, isolation techniques, structure activity relationships and the biological activities of polyisoprenylated benzophenones. In this review, the biological activity of different structures of polyisoprenylated benzophenones isolated from genus Clusia, Garcinia, Vismia, Allanblackia, Moronobea, Symphonia, Hypericum, Tovomita, Tovomiptosis and Ochrocarpus have been described. Therefore, the goal of this review article would be a valuable reference for the natural product chemists and biologistsworking on these PIBs. Furthermore, the review article on polyisoprenylated benzophenoneswould also be useful fromthe drug discovery point of view as cytotoxic agents in near future. This review focuses our understanding about the specific biological effects of Garcinia fruits, which may be useful for predicting other medicinal uses, potential drug or food interactions and may benefit people where the fruits are prevalent and healthcare resources are scarce. © 2013 Elsevier B.V. All rights reserved.

Bhowmik D.,CSIR - Central Electrochemical Research Institute | Kumar G.S.,CSIR - Central Electrochemical Research Institute
Molecular Biology Reports | Year: 2013

Isoquinoline alkaloids and their analogs represent an important class of molecules for their broad range of clinical and pharmacological utility. These compounds are of current interest owing to their low toxicity and excellent chemo preventive properties. These alkaloids can play important role in stabilising the nucleic acid triple helices. The present study has focused on the interaction of five 9-O-(ω-amino) alkyl ether berberine analogs with the DNA triplex poly(dT)·poly(dA)*poly(dT) and the parent duplex poly(dA)·poly(dT) studied using various biophysical techniques. Scatchard analysis of the spectral data indicated that the analogs bind both to the duplex and triplex in a non-cooperative manner in contrast to the cooperative binding of berberine to the DNA triplex. Strong intercalative binding to the DNA triplex structure was revealed from ferrocyanide quenching, fluorescence polarization and viscosity results. Thermal melting studies demonstrated higher stabilization of the Hoogsteen base paired third strand of the DNA triplex compared to the Watson-Crick strand. Circular dichroism studies suggested a stronger perturbation of the DNA triplex conformation by the alkaloid analogs compared to the duplex. The binding was entropy-driven in each case and the entropy contribution to free energy increased as the length of the alkyl side chain increased. The analogs exhibited stronger binding affinity to the triple helical structure compared to the parent double helical structure. © 2013 Springer Science+Business Media Dordrecht.

Ravikumar R.,CSIR - Central Electrochemical Research Institute | Gopukumar S.,CSIR - Central Electrochemical Research Institute
Journal of Power Sources | Year: 2015

(Figure Presented). The lithium ion battery electrolytic solvent, ethylene carbonate:di ethylene carbonate (EC:DEC), influences the exfoliation of semi exfoliated graphite oxide (srGO) further, to promote the better disperstion of Fe3O4 and to enhance the material performance. The composite, semi exfoliated reduced graphite oxide-Magnetite (srGO-Fe3O4) has been prepared using homogeneous co-precipitation method with the aid of microwave oven. The microwave has been introduced to reduce GO and improve the interstitial crystallisation of Fe3O4. srGO-Fe3O4 composite material has been subjected to structural and electrochemical characterization to evaluate their structure and aptness as a possible anode material for lithium ion batteries. srGO-Fe3O4 composite in the 1st cycle demonstrate a better charge capacity of ∼994 mAhg-1 at 75 mA g-1 in the potential range 0.01-3.0 V. Besides, interestingly the cyclability at higher rate (300 mA g-1) is encouraging and demonstrates increased in capacity than the initial over the studied 100 cycles. Thereby, providing proof for the exfoliation driven by EC:DEC in graphitic lamella and by assisting in the expansion of its reaction sites for the better insertion and desersion of lithium ion during cycling. This exfoliation and distribution of particles over srGO matrix has made evident from the FESEM images and Raman shift analysed for the cycled electrode. © 2015 Elsevier B.V. All rights reserved.

Kumar A.,CSIR - Central Electrochemical Research Institute | Kumar S.,CSIR - Central Electrochemical Research Institute | Kumar D.,CSIR - Central Electrochemical Research Institute | Mishra A.,CSIR - Central Electrochemical Research Institute | And 4 more authors.
Acta Crystallographica Section D: Biological Crystallography | Year: 2013

Bacterial N-acetylmuramoyl-l-alanine amidases are cell-wall hydrolases that hydrolyze the bond between N-acetylmuramic acid and l-alanine in cell-wall glycopeptides. Rv3717 of Mycobacterium tuberculosis has been identified as a unique autolysin that lacks a cell-wall-binding domain (CBD) and its structure has been determined to 1.7 Å resolution by the Pt-SAD phasing method. Rv3717 possesses an α/β-fold and is a zinc-dependent hydrolase. The structure reveals a short flexible hairpin turn that partially occludes the active site and may be involved in autoregulation. This type of autoregulation of activity of PG hydrolases has been observed in Bartonella henselae amidase (AmiB) and may be a general mechanism used by some of the redundant amidases to regulate cell-wall hydrolase activity in bacteria. Rv3717 utilizes its net positive charge for substrate binding and exhibits activity towards a broad spectrum of substrate cell walls. The enzymatic activity of Rv3717 was confirmed by isolation and identification of its enzymatic products by LC/MS. These studies indicate that Rv3717, an N-acetylmuramoyl-l-alanine amidase from M. tuberculosis, represents a new family of lytic amidases that do not have a separate CBD and are regulated conformationally. © 2013 International Union of Crystallography.

Singh D.,CSIR - Central Electrochemical Research Institute
CNS and Neurological Disorders - Drug Targets | Year: 2015

Crocus sativus L. (Iridaceae) is an important member of the genus Crocus having high medicinal value. Its dried stigmas, known as “saffron” are being widely used form past many centuries as a food additive, coloring agent, flavoring agent and a potential source of traditional medicine. The stigmas along with other botanical parts of Crocus sativus are being extensively used in ethnomedical treatment of varied central nervous system diseases. In line with its ethnomedical importance, several preclinical studies have been carried out to validate its traditional uses, identify active principle(s), understand pharmacological basis of therapeutic action and explore novel medicinal uses. The bioactive components of Crocus sativus have been found to modulate several synaptic processes via direct/indirect interplay with neurotransmitter receptor functions, interaction with neuronal death/survival pathways and alteration in neuronal proteins expression. Many clinical studies proving beneficial effect of Crocus sativus in depressive disorders, Alzheimer's disease and some other neurological abnormalities have also been carried out. Based on the vast literature reports available, an attempt has been made to comprehend the fragmented information on neuropharmacological aspects, chemistry and safety of Crocus sativus. Although the plant has been well explored, but still a large scope of future preclinical and clinical research exist to explore its potential in neurological diseases, that has been discussed in depth in the present review. © 2015 Bentham Science Publishers.

Kumar S.,CSIR - Central Electrochemical Research Institute | Maiti S.,CSIR - Central Electrochemical Research Institute | Maiti S.,CSIR - National Chemical Laboratory
Biochimie | Year: 2013

RNA-binding proteins are an important class of mediators that regulate cell function and differentiation. Methylation of arginine, a post-translational modification (PTM) found in these proteins, can modulate their function. Arginine can be monomethylated or dimethylated, depending on the type of methyl transferases involved. This paper describes a comparative study of the thermodynamics of unmodified and modified Tat peptide interaction with TAR RNA, where the peptide is methylated at epsilon (ε) and eta (η) nitrogen atoms of guanidinium group of arginine side chain at position 52 or 53. The results indicate that monomethylation of arginine at epsilon (ε) nitrogen atom enhances binding affinity, owing to a more favourable enthalpy component which overrides the less favourable entropy change. In contrast, monomethylation of arginine residue at η nitrogen results in reduced binding affinity originating exclusively from a less favourable enthalpy change leaving entropic component unaffected. However, in case of simultaneous methylation at ε and η positions, the binding parameters remain almost unaffected, when compared to the unmodified peptide. In case of symmetric dimethylation at η position the observed enthalpy change of the binding was found to be smaller than the values obtained for the unmodified peptide. Asymmetric dimethylation at η position showed the most reduced binding affinities owing to less favourable enthalpy changes. These results provide insights that enable elucidation of the biological outcome of arginine methylation as PTMs that regulate protein function, and will contribute to our understanding of how these PTMs are established in vitro and in vivo. © 2013 Elsevier Masson SAS. All rights reserved.

Swarnakar S.,CSIR - Central Electrochemical Research Institute
EXS | Year: 2012

The interest in gelatinases is increased because of their association in diverse human diseases, though the relationship between MMP expression and disease progression is very complex and varies in cell to cell. Targeting gelatinases in disease treatment is complicated by the fact that gelatinases are indispensable for normal development and physiology due to their multifunctionality, possible functional redundancy, context-dependent expression, and activity. They are secreted as inactive zymogens which are processed to become active by removal of N-terminal propeptide. The folded conformation of zymogen is required to keep the gelatinases in its latency. Acting on a broad spectrum of extracellular substrates, the gelatinases (both MMP-2 and MMP-9) are critical to the biological processes. Three-dimensional structures of gelatinase-inhibitor complexes and inhibition profiles of compounds screened on them provide an invaluable source to gain insight into the structural determinants as well as functional selectivity. The quest for selective MMP inhibitors (MMPIs) still remains a challenge in search of successful clinical candidates. An increased understanding of the structure, regulation, and function of the individual MMPs will likely lead to more effective strategies in the development of highly selective inhibitors for any given MMP that can then be exploited to achieve the desired drugs.

Gajula P.K.,CSIR - Central Electrochemical Research Institute | Asthana J.,Indian Institute of Technology Bombay | Panda D.,Indian Institute of Technology Bombay | Chakraborty T.K.,CSIR - Central Electrochemical Research Institute
Journal of Medicinal Chemistry | Year: 2013

We have synthesized eight analogues (D1-D8) of dolastatin 10 containing several unique amino acid subunits. Of these agents, D5 was found to be most effective in inhibiting both HeLa cell proliferation and microtubule assembly in vitro. At low nanomolar concentrations, D5 inhibited the proliferation of several types of cancer cells in culture. D5 bound to tubulin with a dissociation constant of 29.4 ± 6 μM. D5 depolymerized microtubules in cultured cells and produced mulitpolar spindles. At its half-maximal inhibitory concentration (15 nM), D5 strongly suppressed the dynamics of individual microtubules in live MCF-7 cells. D5 increased the accumulation of checkpoint proteins BubR1 and Mad2 at the kinetochoric region and caused G2/M block in these cells. The blocked cells underwent apoptosis with the activation of Jun N-terminal kinase. The results suggested that D5 exerts its antiproliferative action by dampening microtubule dynamics. © 2013 American Chemical Society.

Keshari R.S.,CSIR - Central Electrochemical Research Institute | Verma A.,Sanjay Gandhi Post Graduate Institute of Medical Sciences | Barthwal M.K.,CSIR - Central Electrochemical Research Institute | Dikshit M.,CSIR - Central Electrochemical Research Institute
Journal of Cellular Biochemistry | Year: 2013

Neutrophils/polymorphonuclear leukocytes (PMNs), an important component of innate immune system, release extracellular traps (NETs) to eliminate invaded pathogens; however understanding of the role of signaling molecules/proteins need to be elucidated. In the present study role of p38 MAPK and extracellular signal regulated kinase (ERK) against phorbol 12-myristate 13-acetate (PMA) induced reactive oxygen species (ROS) generation and NETs formation has been investigated. Human neutrophils were treated with PMA to induce free radical generation and NETs release, which were monitored by NBT reduction and elastase/DNA release, respectively. PMA treatment led to the time dependent phosphorylation of p38 MAPK and ERK in PMNs. Pretreatment of PMNs with SB202190 or U0126 did not significantly reduce PMA induce free radical generation, but prevented NETs release. Pretreatment of PMNs with NADPH oxidase inhibitor (diphenyleneiodonium chloride) significantly reduced free radical generation, p38 MAPK and ERK phosphorylation as well as NETs release, suggesting that p38 MAPK and ERK activation was downstream to free radical generation. The present study thus demonstrates ROS dependent activation of ERK and p38 MAPK, which mediated PMA induced NETs release from human neutrophils. J. Cell. Biochem. 114: 532-540, 2013. © 2012 Wiley Periodicals, Inc.

Ghosh S.,Saha Institute of Nuclear Physics | Kar A.,CSIR - Central Electrochemical Research Institute | Chowdhury S.,CSIR - Central Electrochemical Research Institute | Dasgupta D.,Saha Institute of Nuclear Physics
Biochemistry | Year: 2013

Polyguanine sequences fold into G-quadruplex structures in the presence of monovalent cations. It is accepted that the telomeric DNA region consists of G-quadruplex structure. There are reports that potential G-quadruplex forming motifs are also present in the promoter region of some proto-oncogenes such as c-myc, c-kit, KRAS, etc. Small molecules with the potential to stabilize the telomeric DNA quadruplex have emerged as potential anticancer agents. We have studied the interaction of ellipticine, a putative anticancer agent from a plant source, with a human telomeric DNA sequence (H24). Spectroscopic and calorimetric studies indicate that the association of ellipticine with H24 is an entropically driven phenomenon with a 2:3 (H24:ellipticine) stoichiometry. Though ellipticine binding does not induce any major structural perturbation in H24, the association leads to formation of a complex with enhanced thermal stability. An assay with the telomerase repeat amplification protocol shows that ellipticine inhibits telomerase activity in MDAMB-231 breast cancer cell line extracts. This is the first report of the quadruplex binding ability of ellipticine. Using the results, we propose that along with DNA intercalation and/or topoisomerase II inhibition, interaction with the telomeric DNA region and the resultant inhibition of telomerase activity might be an additional mode of action for its anticancer property. © 2013 American Chemical Society.

Hazra S.,CSIR - Central Electrochemical Research Institute | Hossain M.,CSIR - Central Electrochemical Research Institute | Hossain M.,Vidyasagar University | Suresh Kumar G.,CSIR - Central Electrochemical Research Institute
Molecular BioSystems | Year: 2013

Berberine, palmatine and coralyne, the isoquinoline alkaloids distributed in many botanical families, are extensively investigated due to their potential therapeutic actions and clinical utilities. In this work, their binding characteristics to hemoglobin (Hb) were studied by UV-vis absorption spectroscopy, fluorescence spectroscopy, circular dichroism spectroscopy, isothermal calorimetric titration and differential scanning calorimetric techniques. The results indicated that all the three alkaloids caused strong fluorescence quenching of Hb by the static quenching mechanism, but with differing quenching efficiencies. There was a single binding site on Hb for these alkaloids. According to the theory of Förster resonance energy transfer, the binding distances between β-Trp37 of Hb and berberine, palmatine and coralyne were evaluated to be 2.78 nm, 2.64 nm and 3.29 nm, respectively. The result of synchronous fluorescence, circular dichroism and 3D fluorescence revealed that the polarity around Trp residues experienced a significant increase in the presence of alkaloids. The binding was favoured by enthalpy and entropy changes. Results of circular dichroism, 3D and synchronous fluorescence studies confirmed that the binding of the alkaloids significantly changed the secondary structure of Hb. The studies revealed that berberine and palmatine bound to a site near to the α1β2 interface on Hb different than coralyne but the affinity of coralyne was one order higher than that of berberine and palmatine. © 2013 The Royal Society of Chemistry.

Agarwala P.,CSIR - Central Electrochemical Research Institute | Pandey S.,CSIR - Central Electrochemical Research Institute | Mapa K.,CSIR - Central Electrochemical Research Institute | Maiti S.,CSIR - Central Electrochemical Research Institute | Maiti S.,CSIR - National Chemical Laboratory
Biochemistry | Year: 2013

Transforming growth factor β2 (TGFβ2) is a versatile cytokine with a prominent role in cell migration, invasion, cellular development, and immunomodulation. TGFβ2 promotes the malignancy of tumors by inducing epithelial-mesenchymal transition, angiogenesis, and immunosuppression. As it is well-documented that nucleic acid secondary structure can regulate gene expression, we assessed whether any secondary motif regulates its expression at the post-transcriptional level. Bioinformatics analysis predicts an existence of a 23-nucleotide putative G-quadruplex sequence (PG4) in the 5′ untranslated region (UTR) of TGFβ2 mRNA. The ability of this stretch of sequence to form a highly stable, intramolecular parallel quadruplex was demonstrated using ultraviolet and circular dichroism spectroscopy. Footprinting studies further validated its existence in the presence of a neighboring nucleotide sequence. Following structural characterization, we evaluated the biological relevance of this secondary motif using a dual luciferase assay. Although PG4 inhibits the expression of the reporter gene, its presence in the context of the entire 5′ UTR sequence interestingly enhances gene expression. Mutation or removal of the G-quadruplex sequence from the 5′ UTR of the gene diminished the level of expression of this gene at the translational level. Thus, here we highlight an activating role of the G-quadruplex in modulating gene expression of TGFβ2 at the translational level and its potential to be used as a target for the development of therapeutics against cancer. © 2013 American Chemical Society.

Naganjaneyulu K.,CSIR - Central Electrochemical Research Institute | Santosh M.,Kochi University
Geological Journal | Year: 2012

The 800km-long Aravalli-Delhi Fold Belt (ADFB) in the Aravalli Mountains of Rajasthan defines the largest tectonic feature in the northwestern (NW) Indian shield, situated between the late Proterozoic Marwar Basin in the west and the Vindhyan Basin in the east. The final collision between the Aravalli and Delhi domains defining ocean closure and continental amalgamation is critical in understanding the culmination of the Proterozoic Wilson Cycle in NW India. We present for the first time a regional three-dimensional (3-D) gravity model to evaluate the architecture of the continental collision signature of this region. The deep seismic reflection data along a 400km-long profile across the ADFB highlights two sets of reflection bands with opposite dips. The prominent west-dipping reflections observed in the central domain, towards the western margin of the Mangalwar Complex could be related to the Palaeoproterozoic subduction of an oceanic lithosphere, and suggest a clear northwestward subduction polarity. The data showing gravity highs, the high elevation features, and the models proposed in the present study, together with the presence of high-density bodies in the deep crust, is interpreted as a signature of magmatic underplating and/or mafic-ultramafic intrusives. The high elevations and corresponding high-density anomalies at depth can also be explained by domal uplift, following the extrusion of metamorphic orogens into the mid crust, as well as the presence of eclogitized material at depth associated with the subduction-collision tectonics and continental amalgamation. © 2011 John Wiley & Sons, Ltd..

Tandon R.,CSIR - Central Electrochemical Research Institute
Parasitology | Year: 2013

The role of Mycobacterium w (Mw) vaccine as an immunomodulator and immunoprophylactant in the treatment of mycobacterial diseases (leprosy and pulmonary tuberculosis) is well established. The fact that it shares common antigens with leishmanial parasites prompted its assessment as an immunostimulant and as an adjunct to known anti-leishmanials that may help in stimulating the suppressed immune status of Leishmania donovani-infected individuals. The efficacy of Mw vaccine was assessed as an immunomodulator, prophylactically either alone or in combination with anti-leishmanial vaccine, as well as therapeutically as an adjunct to anti-leishmanial treatment in L. donovani-infected hamsters, representing a chronic human Visceral Leishmaniasis (VL) model. Similarly, its efficacy was also evaluated in L. donovani-infected BALB/c mice, representing an acute VL model. The preliminary studies revealed that Mw was ineffective as an immunostimulant and/or immunoprophylactant in hamsters infected with L. donovani, as estimated by T-cell immunological responses. However, in the BALB/c mice-VL model it appeared as an effective immunostimulant but a futile prophylactic agent. It is therefore inferred that, contrary to its role in managing tuberculosis and leprosy infections, Mw vaccine has not been successful in controlling VL infection, emphasizing the need to find detailed explanations for the failure of this vaccine against the disease.

Sengupta D.,CSIR - National Chemical Laboratory | Chattopadhyay A.,CSIR - Central Electrochemical Research Institute
Biochimica et Biophysica Acta - Biomembranes | Year: 2015

G protein-coupled receptors (GPCRs) are the largest class of molecules involved in signal transduction across cell membranes and represent major targets in the development of novel drug candidates. Membrane cholesterol plays an important role in GPCR structure and function. Molecular dynamics simulations have been successful in exploring the effect of cholesterol on the receptor and a general consensus molecular view is emerging. We review here recent molecular dynamics studies at multiple resolutions highlighting the main features of cholesterol-GPCR interaction. Several cholesterol interaction sites have been identified on the receptor that are reminiscent of nonannular sites. These cholesterol hot-spots are highly dynamic and have a microsecond time scale of exchange with the bulk lipids. A few consensus sites (such as the CRAC site) have been identified that correspond to higher cholesterol interaction. Interestingly, high plasticity is observed in the modes of cholesterol interaction and several sites have been suggested to have high cholesterol occupancy. We therefore believe that these cholesterol hot-spots are indicative of 'high occupancy sites' rather than 'binding sites'. The results suggest that the energy landscape of cholesterol association with GPCRs corresponds to a series of shallow minima interconnected by low barriers. These specific interactions, along with general membrane effects, have been observed to modulate GPCR organization. Membrane cholesterol effects on receptor structure and organization, that in turn influences receptor cross-talk and drug efficacy, represent a new frontier in GPCR research. This article is part of a Special Issue entitled: Lipid-protein interactions. Guest Editors: Amitabha Chattopadhyay and Jean-Marie Ruysschaert. © 2015 Elsevier B.V. All rights reserved.

Reddy M.S.,CSIR - Central Electrochemical Research Institute | Thirupathi N.,CSIR - Central Electrochemical Research Institute | Kumar Y.K.,CSIR - Central Electrochemical Research Institute
RSC Advances | Year: 2012

A practical method for the synthesis of substituted quinolines from 2-aminoarylketones (via 1-(2-aminoaryl)-2-yn-1-ols) using mild and simple reaction conditions is described. A study of several electrophiles in various reaction conditions is presented. Out of three electrophilic iodine sources (I 2, NIS and ICl) studied, I 2 was found to work efficiently for the synthesis of 3-iodoquinolines. Several Bronsted acids (pTSA, PPTS, AcOH, TFA, HCl) were able to catalyze the formation of 2,4-substituted quinolines from the same starting materials. Good to excellent overall yields were observed with both aromatic and aliphatic substitutions at the reaction center. © 2012 The Royal Society of Chemistry.

Nayak M.,CSIR - Central Electrochemical Research Institute | Batra S.,CSIR - Central Electrochemical Research Institute
RSC Advances | Year: 2012

Copper-catalyzed intramolecular amination followed by in situ oxidation of primary allylamines generated from the Morita-Baylis-Hillman adducts of 4-iodopyrazolecarbaldehydes for preparing substituted pyrazolo[4,3-b]pyridines is described. The synthetic methodology is versatile and is not affected by the stereochemistry of the allylamine. In contrast, similar coupling reactions employing secondary allylamines as the starting material were unsuccessful. © 2012 The Royal Society of Chemistry.

Sathyamoorthi S.,CSIR - Central Electrochemical Research Institute | Suryanarayanan V.,CSIR - Central Electrochemical Research Institute | Velayutham D.,CSIR - Central Electrochemical Research Institute
Journal of Power Sources | Year: 2014

Performance of activated charcoal based supercapacitor (SC) containing hydroquinone (HQ), as an organic redox shuttle, is evaluated in triethylammonium bis(trifluoromethane)sulfonimide (TEATFSI). Cyclic voltammograms of the SC show pseudocapacitive contribution of HQ and the galvanostatic charge-discharge measurement shows enhanced specific capacitance (72.0 F g-1) and specific energy (31.22 Wh Kg-1). The presence of HQ shows low charge transfer resistance, as confirmed by electrochemical impedance spectroscopy. Cyclic stability of the SC in the redox mediated electrolyte is comparable with that of the protic ionic liquid. © 2014 Elsevier B.V. All rights reserved.

Kumar A.V.N.,CSIR - Central Electrochemical Research Institute | Joseph J.,CSIR - Central Electrochemical Research Institute
Journal of Physical Chemistry C | Year: 2015

Electrochemical modification of electrodes with thin films of metal hexacyanoferrates (MHCF) enhances the interfacial properties such as electrocatalysis, electrochromism, and ion transport properties. Attempts to prepare hybrids of metal hexacyanoferrates along with Au nanoparticles or by substituting the structure of MHCF with another metal ion were reported from various research groups including us. In this work, we report modification of glassy carbon with a new single phase hybrid Zn-NiHCF (hexacyanoferrate prepared in the presence of Zn2+ and Ni2+) electrochemically for the first time. The hybrid film was characterized by a single well reversible redox process centered at 450 mV. The effect of the zinc and nickel ions in the deposition bath on the effectiveness of modification was studied in detail. The modified hybrid films were characterized by voltammetry, chronoamperometry, field emission scanning electron microscopy, X-ray diffractometry, etc. The modified films were used for the electro-oxidation of hydrazine. The deviation from the expected behavior of the hybrid porous films provides evidence for the thin layer mass transport prevailing in the film. Thin layer diffusion behavior in MHCF films for the electrocatalytic oxidation of hydrazine is reported for the first time. The electro-oxidation of hydrazine appears to take place on the glassy carbon (GC) surface. The need for caution in analyzing the electrocatalytic properties of MHCF interfaces is reiterated. © 2014 American Chemical Society.

Mani V.,CSIR - Central Electrochemical Research Institute | Babu G.,CSIR - Central Electrochemical Research Institute | Kalaiselvi N.,CSIR - Central Electrochemical Research Institute
Electrochimica Acta | Year: 2014

Newly identified Li2MnSnO4/C nanocomposite, found to exist as a hybrid consisting of electrochemically active and inactive phases in the form of Li2SnO3, Mn2SnO4 and Li2O has been prepared by oxalyl dihydrazide assisted combustion method. Due to the presence of electrochemically active Li2SnO 3 and Mn2SnO4 phases, an appreciable capacity of 610 and 400 mAh g-1 have been exhibited by Li 2MnSnO4/C anode under a current density of 100 and 500 mA g-1 respectively. The in-situ formed electrochemically inactive Li2O phase and the presence of conducting carbon network offer excellent capacity retention of ∼99% to the title anode. The study demonstrates the possibility of exploiting Li2MnSnO4/C as a high capacity and high rate lithium battery anode with appreciable coulombic efficiency. © 2014 Published by Elsevier Ltd.

Sasikala S.,CSIR - Central Electrochemical Research Institute | Meenakshi S.,CSIR - Central Electrochemical Research Institute | Bhat S.D.,CSIR - Central Electrochemical Research Institute | Sahu A.K.,CSIR - Central Electrochemical Research Institute
Electrochimica Acta | Year: 2014

Composite membranes comprising functionalized Bentonite (HSO 3-BEN)-sulfonated poly(ether ether ketone) (sPEEK) is fabricated as an alternative polymer electrolyte membrane (PEM) for direct methanol fuel cells (DMFCs). K+-Bentonite is functionalized through silane condensation to introduce organo sulfonic acid groups. Ion-exchange capacity, sorption and proton conductivity for the composite membranes have been investigated. These composite membranes are also characterised for their mechanical and thermal properties. DMFCs employing sPEEK-HSO3-BEN composite membrane delivered peak power density of 140 mW cm-2, while peak power density of 71 mW cm-2 is obtained for the DMFC employing pristine sPEEK membrane at 70 °C. The results show that these composite membranes exhibits lower methanol permeability in comparison to pristine sPEEK membrane. © 2014 Elsevier Ltd.

Sharma A.,CSIR - Central Electrochemical Research Institute
Biomolecular Concepts | Year: 2015

Transgenerational epigenetic inheritance in animals has increasingly been reported in recent years. Controversies, however, surround this unconventional mode of heredity, especially in mammals, for several reasons. First, its existence itself has been questioned due to perceived insufficiency of available evidence. Second, it potentially implies transfer of hereditary information from soma to germline, against the established principle in biology. Third, it inherently requires survival of epigenetic memory across reprogramming, posing another fundamental challenge in biology. Fourth, evolutionary significance of epigenetic inheritance has also been under debate. This article pointwise addresses all these concerns on the basis of recent empirical, theoretical and conceptual advances. 1) Described here in detail are the key experimental findings demonstrating the occurrence of germline epigenetic inheritance in mammals. 2) Newly emerging evidence supporting soma to germline communication in transgenerational inheritance in mammals, and a role of exosome and extracellular microRNA in this transmission, is thoroughly discussed. 3) The plausibility of epigenetic information propagation across reprogramming is highlighted. 4) Analyses supporting evolutionary significance of epigenetic inheritance are briefly mentioned. Finally, an integrative model of 'evolutionary transgenerational systems biology' is proposed to provide a framework to guide future advancements in epigenetic inheritance. © 2015 by De Gruyter.

Vijayalakshmy S.,CSIR - Central Electrochemical Research Institute | Subramanian B.,CSIR - Central Electrochemical Research Institute
Electrochimica Acta | Year: 2014

Zinc Oxide (ZnO) block layers of 300 and 600 nm thicknesses are prepared by Pulsed Laser Deposition (PLD) onto FTO coated glass substrates at substrate temperature of 400 °C. X-ray diffraction (XRD) analysis indicate that they are polycrystalline in nature and have hexagonal structure. The surface morphological studies by FESEM, reveal the uniform surface coverage of the grains on the surface of the films. Optical transmittance of 90% in the visible light region with the band gap value of 3.35 eV is measured. Mesoporous ZnO layers with thickness of about 9.8 μm prepared by a chemical method are applied onto the laser ablated ZnO blocking layer and this stack is used as the photoanode of dye sensitized solar cells (DSSCs). The formation of ZnO nanorods is observed in TEM image. Platinum thin films of 100 nm are electron beam evaporated on FTO coated glass substrates which are used as counter electrodes. The performance of the cell with a Voc of 0.551 V, a Jsc of 6.96 mA cm-2, a fill factor of 0.76 and an efficiency of 3.02% is obtained. It is noticed that the conversion efficiency of the DSSCs is affected by the thickness of the passivating layer. © 2014 Elsevier Ltd.

Rao C.N.R.,CSIR - Central Electrochemical Research Institute | Voggu R.,CSIR - Central Electrochemical Research Institute
Materials Today | Year: 2010

Charge-transfer between electron-donor and -acceptor molecules is a widely studied subject of great chemical interest. Some of the charge-transfer compounds in solid state exhibit novel electronic properties. In the last two to three years, occurrence of molecular charge-transfer involving single-walled carbon nanotubes (SWNTs) and graphene has been demonstrated. This interaction gives rise to significant changes in the electronic properties of these nanocarbons. We examine charge-transfer phenomenon in graphene and SWNTs in this article in view of its potential utility in device applications. © 2010 Elsevier Ltd.

Qidwai T.,CSIR - Central Electrochemical Research Institute | Khan F.,CSIR - Central Electrochemical Research Institute
Chemical Biology and Drug Design | Year: 2012

Plasmodium falciparum, a causitive agent of malaria, is the third most prevalent factor for mortility in the world. Falciparum malaria is an example of evolutionary and balancing selection. Because of mutation and natural selection, the parasite has developed resistance to most of the existing drugs. Under such circumstances, there is a growing need to develop new molecular targets in P. falciparum. A four membrane bound organelles called apicoplast, very much similar to that of chloroplast of plants, have been found in parasite. Therefore, the proteins involved in metabolic pathways of apicoplasts are important drug targets. Among the pathways in apicoplast, fatty acid biosynthetic pathway is the most important metabolic pathway in P. falciparum. Several studies have explored the role of different proteins involved in this pathway and antimalarial compounds against this target. In this review, we have studied the role of different proteins in fatty acid metabolism and designing, synthesis and evaluation of compounds against the targets identified in fatty acid metabolic pathway. © 2012 John Wiley & Sons A/S.

Vijayalakshmy S.,CSIR - Central Electrochemical Research Institute | Subramanian B.,CSIR - Central Electrochemical Research Institute
Electrochimica Acta | Year: 2014

Titanium dioxide (TiO2) thin films as block layers are prepared by DC reactive magnetron sputtering. X-ray diffraction (XRD) and TEM-(SAED) analyses of the films reveal that they are polycrystalline in nature and have tetragonal structure with preferred orientation along the (101) direction. The surface morphological studies by FESEM and AFM reveal the uniform surface coverage of the grains on the surface of the films. An optical transmittance value of 80% in the visible light region with the optical band gap value of 3.2 eV is measured. This sputtered TiO2 thin film is used as a blocking layer over which a thick layer of TiO2 of about 10 μm was prepared using TiO2 paste and this stack is used as the photoanode of a DSSC cell. Electron beam evaporated platinum thin film on FTO coated glass substrate is used as counter electrode. The performance of the cell with a Voc of 0.698 V, a Jsc of 6.8 mAcm-2 and an efficiency of 4.2% was achieved © 2013 Elsevier Ltd.

Vasudevan S.,CSIR - Central Electrochemical Research Institute
Environmental science and pollution research international | Year: 2011

PURPOSE AND AIM: The present study provides an optimization of electrocoagulation process for the simultaneous removal of heavy metals such as mercury, lead, and nickel from water. In doing so, the thermodynamic, adsorption isotherm and kinetic studies were also carried out. Magnesium alloy, magnesium, aluminum, and mild steel sheet of size 2 dm(2) were used as anode and galvanized iron as cathode. To optimize the maximum removal efficiency, different parameters like effect of initial concentration, effect of temperature, pH, and effect of current density were studied. Mercury-, lead-, and nickel-adsorbed magnesium hydroxide coagulant was characterized by SEM and EDAX. The results showed that the maximum removal efficiency was achieved for mercury, lead, and nickel with magnesium alloy as anode and galvanized iron as cathode at a current density of 0.15 Å/dm(2) and pH of 7.0. The adsorption of mercury, lead, and nickel are preferably fitting the Langmuir adsorption isotherm suggests monolayer coverage of adsorbed molecules. The adsorption process follows second-order kinetics. Temperature studies showed that adsorption was endothermic and spontaneous in nature. The magnesium hydroxide generated in the cell removes the heavy metals present in the water and reduces to a permissible level, making it drinkable.

Dhathathreyan A.,CSIR - Central Electrochemical Research Institute | Nair B.U.,CSIR - Central Electrochemical Research Institute
Journal of Physical Chemistry B | Year: 2010

This work reports the formation of stable nanoassemblies of short pentapeptides LKLKL (pepI) and their mutated sequence LKKLL (pepII) obtained from their Langmuir-Blodgett films transferred onto hydrophilic and hydrophobic silicon substrates. The adsorption and assembly of the LB films of these peptides on solid surfaces have been studied by quartz crystal microbalance, surface plasmon resonance, and scanning electron microscopy. Both pepI and pepII assemble into nanosized ribbons, with diameters around 20-25 nm and lengths greater than 5 μm on hydrophobic surface, and tend to aggregate on hydrophilic surfaces with pepII showing twisted structures. Circular dichroic spectra of the films on a hydrophobic surface showed formation of a β-sheet-like structure, while the corresponding solution spectra did not show any specific secondary structure. Our results demonstrate the formation of a two-dimensional dense array of nanoassemblies with either vertical or horizontal patterns from such short peptides that may find application in nanotechnology. © 2010 American Chemical Society.

Angulakshmi N.,CSIR - Central Electrochemical Research Institute | Stephan A.M.,CSIR - Central Electrochemical Research Institute
Electrochimica Acta | Year: 2014

Poly(vinylidene fluoride- hexafluoropropylene) (PVdF-HFP)/poly (vinyl chloride) (PVC)/(PVdF-HFP) based- trilayer porous polymeric membrane (PM) was prepared by electrospinning for lithium batteries. The formation of beads was significantly reduced by increasing the concentration and by reducing the surface tension of the polymer solutions. Although, single layer PVdF-HFP membrane exhibited high porosity and uptake of electrolyte, its mechanical integrity was found to be poor (not free-standing). On the other hand, electrospinning of PVC over PVdF-HFP enhanced the mechanical integrity of the membrane. The prepared membranes were subjected to SEM, ionic conductivity, electrolyte uptake and shrinkage analyses. A 2032-type coin cell composed of Li/PM/LiFePO4 has been assembled and its cycling profile was examined at different C-rates. The (PVdF-HFP)/PVC/(PVdF-HFP) trilayer membrane can be a strong contender for lithium battery applications. © 2014 Elsevier Ltd.

Biswas S.,CSIR - Central Electrochemical Research Institute | Batra S.,CSIR - Central Electrochemical Research Institute
European Journal of Organic Chemistry | Year: 2012

An efficient one-step synthesis of 2-amino-5H-pyrimido[5,4-b]indoles through a copper-catalyzed cascade reaction between 3-haloindole-2-carbaldehydes and guanidine hydrochloride is described. In contrast, the base-mediated reactions of either 3-haloindole-2-carbaldehydes or substituted indole-2-carbaldehydes with substituted amidine hydrochlorides in DMSO result in the formation of 2-(1,3,5-triazin-2-yl)-1H-indole derivatives in one step in excellent yields. Studies toward exploring the utility of the method demonstrate that even substituted benzaldehydes undergo a similar reaction to efficiently yield 2,4,6-trisubstituted 1,3,5-triazines. A plausible mechanism for the formation of substituted 1,3,5-triazines identifies the role of DMSO as an oxidant during the reaction. The synthesis of 2-amino-5H-pyrimido[5,4-b]indoles from 3-haloindole-2-carbaldehyde and guanidine hydrochloride is described. In contrast, 3-haloindole-2-carbaldehydes or indole-2-carbaldehydes react with substituted amidine hydrochlorides to give 2-(1,3,5-triazin-2-yl)-1H-indole derivatives in excellent yields. The latter protocol was used to prepare 2,4,6-trisubstituted 1,3,5-triazines. © 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Sarmah P.P.,CSIR - Central Electrochemical Research Institute | Dutta D.K.,CSIR - Central Electrochemical Research Institute
Applied Catalysis A: General | Year: 2014

Rh0-nanoparticles of around 5 nm size distributed homogeneously into the nanopores of acid activated Montmorillonite clay were generated by incipient wetness impregnation of RhCl3, followed by reduction with ethylene glycol. Acid activation of the Montmorillonite clay was carried out by treating with H2SO4 under controlled condition to increase the surface area by generating nanopores upto about 10 nm sizes, which act as a host and stabilize nanoparticles into the pores. The synthesized Rh 0-nanoparticles-clay composites characterized by PXRD, SEM-EDX, HRTEM, XPS and N2-adsorption confirm generation of Rh 0-nanoparticle below 5 nm size and fully reduced to metallic state. The supported metal nanoparticles serve as efficient heterogeneous catalyst for reduction of some important aromatic carbonyl compounds leading to corresponding alcohols through transfer hydrogenation up to 100% conversion (GC) and selectivity, where isopropanol was used as both solvent and reductant. The catalyst remained active for several runs without significant loss of its catalytic activities. © 2013 Elsevier Ltd. All rights reserved.

Hutait S.,CSIR - Central Electrochemical Research Institute | Biswas S.,CSIR - Central Electrochemical Research Institute | Batra S.,CSIR - Central Electrochemical Research Institute
European Journal of Organic Chemistry | Year: 2012

Acid-catalyzed Pomeranz-Fritsch-type reaction between the acetal group at C-1 and the arene unit of the benzyl group at N-9 in 9-substituted benzyl-1-(dimethoxymethyl)-9H-β-carboline affords fused-β-carbolines that can be readily oxidized to furnish a maxonine-type framework. Mechanistically, the reaction proceeds via a protonated aldehyde as the intermediate, which undergoes attack by the activated arene subunit of the benzyl moiety. On the other hand, the Morita-Baylis-Hillman adducts of 1-formyl-N-substituted benzyl-9H-β-carbolines undergo an efficient P 2O 5-mediated intramolecular Friedel-Crafts reaction between the secondary hydroxy group and the activated phenyl group of the benzyl subunit to yield fused-β-carbolines. Investigations into the scope of the substrates reveal that the success of the methodology relies on the degree of activation of the phenyl ring. For substrates having less-activated phenyl groups, indolizinoindole derivatives were isolated in moderate yields only. A simple and efficient synthesis of maxonine analogues from N-substituted benzyl 1-formyl-9H-β-carbolines through sequential Pomeranz-Fritsch reaction and oxidation is demonstrated. In an extension of the study, synthesis of new fused β-carbolines has been accomplished by P 2O 5-mediated Friedel-Crafts reaction of the Morita-Baylis-Hillman adducts of these aldehydes. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Nayak M.,CSIR - Central Electrochemical Research Institute | Rastogi N.,Sanjay Gandhi Post Graduate Institute of Medical Sciences | Batra S.,CSIR - Central Electrochemical Research Institute
European Journal of Organic Chemistry | Year: 2012

An efficient copper-catalyzed cascade reaction of 4- iodopyrazolecarbaldehydes and 4-iodopyrazolecarboxamides with substituted amidines for the preparation of substituted pyrazolo[4,3-d]pyrimidines and pyrazolo[4,3-d]pyrimidin-7(6H)-ones, respectively, is described. A copper-mediated, one-step synthesis of substituted pyrazolo[4,3-d]pyrimidines and pyrazolo[4,3-d]pyrimidin-7(6H)-ones by reaction between 4-iodopyrazole derivatives and substituted amidines is reported. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Kundu S.,CSIR - Central Electrochemical Research Institute
Colloids and Surfaces A: Physicochemical and Engineering Aspects | Year: 2014

A facile route for the formation of shape-selective ZnO nanoarchitectures has been demonstrated. ZnO nanostructures with variable sizes and shapes have been successfully synthesized using microwave (MW) heating for 5. min in an aqueous solution containing Zn(II) salt, CTAB, 2,7-DHN, and NaOH. The size and shape of the nanomaterials can be controlled by tuning the molar ratio of Zn(II) salt to CTAB and by controlling other reaction parameters. This process exclusively generates different shapes, e.g., 'bacteria-like', 'larva-like', 'flake-like' and 'flower-like', on a shorter time scale. The incorporation of alkaline 2,7-DHN plays a dual role; it controls the solution pH, and it directly affects the growth process of various ZnO crystal facets. Shape-selective ZnO nanostructures have been utilized as an excellent photo-catalyst for the degradation of methyl red (MeR) under UV illumination. Among the various shapes examined, the 'flower-like' nanostructure exhibited superior photo-catalyst activity due to its special structural features. Furthermore, the synthesized shape-selective ZnO nanostructures could be useful in large-scale heterogeneous photo-catalysis reactions to target wastewater contamination and environmental pollution. Moreover, they could also be useful as novel gas sensors and as suitable templates for the synthesis of other nanomaterials with uniform morphologies. © 2013 Elsevier B.V.

Borah B.J.,CSIR - Central Electrochemical Research Institute | Borah S.J.,CSIR - Central Electrochemical Research Institute | Saikia L.,CSIR - Central Electrochemical Research Institute | Dutta D.K.,CSIR - Central Electrochemical Research Institute
Catalysis Science and Technology | Year: 2014

The in situ generation of Cu0-nanoparticles into the nanopores of modified montmorillonite and their catalytic performance in the three component (A3) coupling reactions of aldehyde, amine and alkyne to synthesize propargylamines have been described here. The modification of montmorillonite was carried out with HCl under controlled conditions for generating nanopores into the matrix and these pores act as a "host" for the in situ generation of Cu0-nanoparticles. The Cu 0-nanoparticles were generated in the nanopores of the acid activated clay mineral matrix by the successful loading of a Cu(CH3COO) 2 metal precursor using an incipient wetness impregnation technique followed by reduction with NaBH4. The TEM study reveals that Cu 0-nanoparticles of below 10 nm in size are evenly distributed on the support. The synthesized Cu0-nanoparticles exhibit a face centered cubic (fcc) lattice. The Cu0-nanoparticles serve as an efficient green and heterogeneous catalyst for three-component coupling via C-H alkyne-activation to synthesize propargylamines with excellent yields (82-94%) and 100% selectivity under mild reaction conditions without requiring any additives or an inert atmosphere. The nanocatalysts can be recycled and reused several times without significant loss of their catalytic activity. This journal is © the Partner Organisations 2014.

Yadav A.K.,CSIR - Central Electrochemical Research Institute | Kumar D.,CSIR - Central Electrochemical Research Institute | Dash D.,CSIR - Central Electrochemical Research Institute
PLoS ONE | Year: 2012

The statistical validation of database search results is a complex issue in bottom-up proteomics. The correct and incorrect peptide spectrum match (PSM) scores overlap significantly, making an accurate assessment of true peptide matches challenging. Since the complete separation between the true and false hits is practically never achieved, there is need for better methods and rescoring algorithms to improve upon the primary database search results. Here we describe the calibration and False Discovery Rate (FDR) estimation of database search scores through a dynamic FDR calculation method, FlexiFDR, which increases both the sensitivity and specificity of search results. Modelling a simple linear regression on the decoy hits for different charge states, the method maximized the number of true positives and reduced the number of false negatives in several standard datasets of varying complexity (18-mix, 49-mix, 200-mix) and few complex datasets (E. coli and Yeast) obtained from a wide variety of MS platforms. The net positive gain for correct spectral and peptide identifications was up to 14.81% and 6.2% respectively. The approach is applicable to different search methodologies- separate as well as concatenated database search, high mass accuracy, and semi-tryptic and modification searches. FlexiFDR was also applied to Mascot results and showed better performance than before. We have shown that appropriate threshold learnt from decoys, can be very effective in improving the database search results. FlexiFDR adapts itself to different instruments, data types and MS platforms. It learns from the decoy hits and sets a flexible threshold that automatically aligns itself to the underlying variables of data quality and size. © 2012 Yadav et al.

Kumar V.K.R.,CSIR - Central Electrochemical Research Institute | Krishnakumar S.,CSIR - Central Electrochemical Research Institute | Gopidas K.R.,CSIR - Central Electrochemical Research Institute
European Journal of Organic Chemistry | Year: 2012

The synthesis and characterization of four generations of palladium nanoparticle-cored Fréchet-type dendrimers (Pd-G n) possessing direct palladium-carbon bonds are reported. These core-shell materials have been synthesized by the simultaneous reduction of different generation diazodendrons and Pd II in an organic medium. The resulting organic-inorganic hybrid materials were characterized by IR, NMR and UV/Vis spectroscopic techniques. The formation of nearly spherical particles of 2-4 nm diameter was confirmed by TEM studies. The efficiency of one member of this series, Pd-G 1, in catalysing important C-C bond-forming reactions such as Suzuki, Stille and Hiyama coupling reactions was investigated. The results clearly show that Pd-G 1 can efficiently catalyse the cross-coupling of arylboronic acids, aryl stannanes and organosilicon compounds with differently substituted aryl halides in addition to efficiently catalysing hydrogenation reactions. The catalyst exhibited good recovery and recyclability in Suzuki coupling reactions. The study suggests that a single catalyst capable of catalysing several reactions can be designed. Palladium nanoparticle-cored dendrimers synthesized by the reduction of Pd II in the presence of diazodendrons find use as efficient catalysts for different cross-coupling reactions with good recyclability. © 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Batchu H.,CSIR - Central Electrochemical Research Institute | Batra S.,CSIR - Central Electrochemical Research Institute
European Journal of Organic Chemistry | Year: 2012

A versatile synthesis of 2-(substituted phenyl)-6,7-dihydro-1H-indol-4(5H)- ones from adducts of the Morita-Baylis-Hillman reaction between 2-oxo-2-(substituted phenyl)acetaldehydes and cyclohex-2-enone under mild conditions is described. Application of adducts prepared by the Morita-Baylis-Hillman reaction between 2-oxo-2-(substituted phenyl)acetaldehydes and cyclohex-2-enone for the synthesis of 2-(substituted phenyl)-6,7-dihydro- 1H-indol-4(5H)-ones has been described. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Basu A.,CSIR - Central Electrochemical Research Institute
Scientometrics | Year: 2014

Due to recession in the world economy there is a trend towards a reduction in growth of R&D expenditure in the G7 countries. At the same time countries like China and Korea are investing more in scientific research. We compare the differences in the inputs to science for different countries and explore the level of efficiency in the output of scientific papers with respect to inputs such as manpower and investment. We find that the EU countries are relatively more efficient than Japan, the USA and also China and Korea so far as the production of papers is concerned. However, if efficiency is considered in terms of patents, Japan Korea and the USA are ahead. We compare our results with Albuquerque's model linking patent to paper ratios and development, and find significant deviations for some countries. We deduce that there has been a shift from publishing towards patenting in certain countries and link it to high contribution from the business sector to R&D expenditure. Preliminary results of this analysis have been presented in Basu (In Proceedings of the 14th International Society for Scientometrics and Informetrics (ISSI) Conference, 2013). © 2014 Akadémiai Kiadó, Budapest, Hungary.

Hazarika S.,CSIR - Central Electrochemical Research Institute | Dutta N.N.,CSIR - Central Electrochemical Research Institute | Rao P.G.,CSIR - Central Electrochemical Research Institute
Separation and Purification Technology | Year: 2012

The dissolution kinetics of lignocellulose from a suitable source of north east India has been studied in ionic liquid at room temperature. The measured profiles of time versus concentration of lignocelluloses were interpreted from a kinetic model and the rate constant was obtained by regression analysis of the data and the values of the rate constant was found to be 54.79 × 10 -8 cm/s. The dissolution profiles indicate clear prospect of separating the constituents by suitable methods. Recovery of ionic liquid has also been studied by membrane technology using commercial nanofiltration membrane. The effect of applied pressure gradient (ΔP) and concentration of lignocellulose on the rejection and membrane fouling was studied over a range of pressure and concentration of 2-5 bar and 0.01-0.03 mmole L -1 respectively. The solution flux increases with pressure in the pressure range studied indicate the effect of concentration polarization is not significant in this range. The permeation phenomenon has been analyzed on the basis of pore flow transport model and is well fitted with the experimental values. © 2012 Elsevier B.V. All rights reserved.

Nayak M.,CSIR - Central Electrochemical Research Institute | Batra S.,CSIR - Central Electrochemical Research Institute
European Journal of Organic Chemistry | Year: 2012

A facile and efficient synthesis of new fused pyrazoles through the Pd(OAc) 2-mediated heteroarylation of heteroarene C-H bonds in Morita-Baylis-Hillman derivatives of 4-iodopyrazolecarbaldehydes is described. © 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Karmakar R.,Indian Institute of Technology Kharagpur | Karmakar R.,TU Braunschweig | Pahari P.,Indian Institute of Technology Kharagpur | Pahari P.,CSIR - Central Electrochemical Research Institute | Mal D.,Indian Institute of Technology Kharagpur
Chemical Reviews | Year: 2014

Small molecule natural products have been the mainstay of research in organic chemistry since its early development. The established classes of natural products, like alkaloids, amino acids, flavonoids, quinonoids, steroids, and terpenoids, have played vital roles in the discovery of new drugs. Research on the chemistry of natural products is continuing to generate new leads in medicinal chemistry. A case in point is the emerging class of compounds called isobenzofuranones, commonly termed as phthalides. NBP is a viscous oil and occurs as the major component of celery oil. It also exhibits antibacterial, antiviral, and antihypertensive activity. Mycophenolic acid is in clinical trial for the prevention and reversal of transplant rejection and anticancer. Dimeric forms of this core structure feature a few natural products.

Prathap G.,CSIR - Central Electrochemical Research Institute
Scientometrics | Year: 2011

Quality, Quantity, Performance,...An unresolved challenge in performance evaluation in a very general context that goes beyond scientometrics, has been to determine a single indicator that can combine quality and quantity of output or outcome. Toward this end, we start from metaphysical considerations and propose introducing a new name called Quasity to describe those quantity terms which incorporate a degree of quality and best measures the output. The product of quality and quasity then becomes an energy term which serves as a performance indicator. Lessons from kinetics, bibliometrics and sportometrics are used to build up this theme. © 2011 Akadémiai Kiadó, Budapest, Hungary.

Basu A.,CSIR - Central Electrochemical Research Institute | Jaisankar P.,CSIR - Central Electrochemical Research Institute | Kumar G.S.,CSIR - Central Electrochemical Research Institute
RSC Advances | Year: 2012

This manuscript describes the interaction of 9-O-substituted analogues of the plant alkaloid berberine with single stranded (ss) poly(A). Three new analogues of berberine with aryl/arylalkyl amino carbonyl methyl substituents at the 9-position of the isoquinoline chromophore were evaluated for their binding to ss poly(A) by a wide variety of biophysical techniques. The results indicated that these analogues exhibited several-fold higher binding affinities than berberine. The Scatchard binding isotherms revealed that all the analogues retained the cooperative binding mode of berberine. Circular dichroism and FTIR studies unequivocally established the strong interaction potential of the analogues to ss poly(A). Optical melting and the unique dilution experiments revealed that these analogues induced self-structure formation in poly(A) and the nature of the substituent was important for the ease of formation of self-structure. Energetics of the binding suggested an entropy driven binding for the analogues in sharp contrast to the enthalpy driven binding of berberine. The introduction of the aryl/arylalkyl amino carbonyl methyl substituent thus switched the enthalpy driven binding of berberine to entropy dominated binding. Salt and temperature dependent calorimetric studies established the involvement of multiple weak noncovalent interactions in the binding process. The study also revealed that the spacer length at the 9-position had an important role in the self-structure induction. This journal is © 2012 The Royal Society of Chemistry.

Nithya C.,CSIR - Central Electrochemical Research Institute | Syamala Kumari V.S.,CSIR - Central Electrochemical Research Institute | Gopukumar S.,CSIR - Central Electrochemical Research Institute
Physical Chemistry Chemical Physics | Year: 2011

Layered mixed oxides LiNixCoyMn1-x-yO 2 (0 ≤ x, y ≤ 0.5) synthesized by a sol-gel method using tartaric acid as a chelating agent, and their structural and electrochemical properties are investigated by thermal analysis, XRD, SEM, FT-IR and XPS studies. The higher composition of Co leads to cation disorder and shrinks the cell volume. Electrochemical behaviour of the synthesized materials is evaluated by Galvanostatic charge/discharge studies using 2016 type coin cells. The cycling studies are carried out in the voltage limits of 2.7 to 4.6, 4.8 and 4.9 V at current rates of C/10 and C/5 respectively. The composition LiNi 0.4Co0.1Mn0.5O2 exhibits an average discharge capacity of 192 mA h g-1 at the current density of 0.612 mA cm-2 (C/5) in the voltage range of 2.7-4.9 V as compared to the discharge capacity of 155 and 175 mA h g-1 in the potential range of 2.7-4.6 and 2.7-4.8 V over the 50 investigated cycles. The effect of higher charge voltage at 4.9 V on the electrochemical performance of LiNi xCoyMn1-x-yO2 oxide materials has not previously been reported. © the Owner Societies. 2011.

Suresh Kumar G.,CSIR - Central Electrochemical Research Institute
Journal of Biosciences | Year: 2012

Studies on RNA targeting by small molecules to specifically control certain cellular functions is an area of remarkable current interest. For this purpose, a basic understanding of the molecular aspects of the interaction of small molecules with various RNA structures is essential. Alkaloids are a group of natural products with potential therapeutic utility, and very recently, their interaction with many RNA structures have been reported. Especially noteworthy are the protoberberines and aristolochia alkaloids distributed widely in many botanical families. Many of the alkaloids of these group exhibit excellent binding affinity to many RNA structures that may be exploited to develop RNA targeted therapeutics. This review attempts to present the current status on the understanding of the interaction of these alkaloids with various RNA structures, mainly highlighting the biophysical aspects. © Indian Academy of Sciences.

Rastogi N.,CSIR - Central Electrochemical Research Institute | Mishra D.P.,CSIR - Central Electrochemical Research Institute
Cell Division | Year: 2012

Proteasomes are multicatalytic protease complexes in the cell, involved in the non-lysosomal recycling of intra-cellular proteins. Proteasomes play a critical role in regulation of cell division in both normal as well as cancer cells. In cancer cells this homeostatic function is deregulated leading to the hyperactivation of the proteasomes. Proteasome inhibitors (PIs) are a class of compounds, which either reversibly or irreversibly block the activity of proteasomes and induce cancer cell death. Interference of PIs with the ubiquitin proteasome pathway (UPP) involved in protein turnover in the cell leads to the accumulation of proteins engaged in cell cycle progression, which ultimately put a halt to cancer cell division and induce apoptosis. Upregulation of many tumor suppressor proteins involved in cell cycle arrest are known to play a role in PI induced cell cycle arrest in a variety of cancer cells. Although many PIs target the proteasomes, not all of them are effective in cancer therapy. Some cancers develop resistance against proteasome inhibition by possibly activating compensatory signaling pathways. However, the details of the activation of these pathways and their contribution to resistance to PI therapy remain obscure. Delineation of these pathways may help in checking resistance against PIs and deducing effective combinational approaches for improved treatment strategies. This review will discuss some of the signaling pathways related to proteasome inhibition and cell division that may help explain the basis of resistance of some cancers to proteasome inhibitors and underline the need for usage of PIs in combination with traditional chemotherapy. © 2012 Rastogi and Mishra; licensee BioMed Central Ltd.

Verma R.S.,CSIR - Central Electrochemical Research Institute | Padalia R.C.,CSIR - Central Electrochemical Research Institute | Chauhan A.,CSIR - Central Electrochemical Research Institute
Journal of the Science of Food and Agriculture | Year: 2012

Background: Two Ocimum basilicum cultivars, 'Vikarsudha' and 'CIM-Saumya', grown in the Kumaon region of western Himalaya were evaluated for their essential oil yield and composition at different stages of plant growth during two distinct cropping seasons (spring-summer and rain-autumn). Results: The highest yield of essential oil was obtained at full bloom stage in both cultivars in both cropping seasons. The essential oils obtained from different stages in two cropping seasons were analysed by capillary gas chromatography with flame ionisation detection, and gas chromatography-mass spectrometry. The major component of cultivar 'Vikarsudha' was methyl chavicol (84.3-94.3%), while for cultivar 'CIM-Saumya' the main components were methyl chavicol (62.5-77.6%) and linalool (14.4-34.1%). Conclusion: This study clearly indicated that cultivar, cropping season, plant ontogeny and plant part had significant effects on the yield and quality of the essential oil of O. basilicum. Further, the amount of methyl chavicol in the cultivars grown in this region was higher than in cultivars from other parts of India. © 2011 Society of Chemical Industry.

Singh R.,CSIR - Central Electrochemical Research Institute | Saini N.,CSIR - Central Electrochemical Research Institute
Journal of Cell Science | Year: 2012

A number of anti-cancer strategies aim to target the mitochondrial apoptotic machinery to induce tumour cell death. Mitochondria play a key role as death amplifiers by releasing apoptogenic factors from the mitochondrial inter-membrane space into the cytosol. BCL2 proteins are known for their ability to regulate both mitochondrial physiology and cell death, and their deregulated expression often renders cancer cells insensitive to apoptosis-inducing anticancer drugs. Recently, a few microRNAs, a novel class of gene regulators, have been demonstrated to regulate expression of some members of the BCL2 family. Here, we have combined computational and experimental approaches to identify miRNAs that can regulate the anti-apoptotic protein BCL2. We report that miR-195, miR-24-2 and miR-365-2 act as negative regulators of BCL2 through direct binding to their respective binding sites in the 3'-UTR of the human BCL2 gene. Ectopic expression of miR-195, miR-24-2 and miR-365-2 individually led to a significant reduction of the levels of BCL2 protein. Additionally, we found that overexpression of these miRNAs induced dissipation of the mitochondrial membrane potential and release of cytochrome c from mitochondria into the cytosol. Furthermore, we demonstrated that overexpression of these miRNAs not only caused an increase in apoptosis but also augmented the apoptotic effect of etoposide in breast cancer MCF7 cells. These data not only show the apoptotic nature of miR-195, miR-24-2 and miR-365-2 but also highlight the therapeutic potential of these miRNAs. © 2012.

Randhawa V.,CSIR - Central Electrochemical Research Institute | Bagler G.,CSIR - Central Electrochemical Research Institute
OMICS A Journal of Integrative Biology | Year: 2012

Network-biology inspired modeling of interactome data and computational chemistry have the potential to revolutionize drug discovery by complementing conventional methods. We consider asthma, a complex disease characterized by intricate molecular mechanisms, for our study. We aim to integrate prediction of potent drug targets using graph-theoretical methods and subsequent identification of small molecules capable of modulating activity of the best target. In this work, we construct the protein interactome underlying this disease: Asthma Protein Interactome (API). Using a strategy based on network analysis of the interactome, we identify a set of potential drug targets for asthma. Topologically and dynamically, v-src sarcoma (Schmidt-Ruppin A-2) viral oncogene homolog (SRC) emerges as the most central target in API. SRC is known to play an important role in promoting airway smooth muscle cell growth and facilitating migration in airway remodeling. From interactome analysis, and with the reported role in respiratory mechanisms, SRC emerges as a promising drug target for asthma. Further, we proceed to identify leads for SRC from a public database of small molecules. We predict two potential leads for SRC using ligand-based virtual screening methodology. © Mary Ann Liebert, Inc. 2012.

Sankaranarayanan K.,CSIR - Central Electrochemical Research Institute | Sathyaraj G.,CSIR - Central Electrochemical Research Institute | Nair B.U.,CSIR - Central Electrochemical Research Institute | Dhathathreyan A.,CSIR - Central Electrochemical Research Institute
Journal of Physical Chemistry B | Year: 2012

Hydrated phenylalanine ionic liquid (Phe-IL) has been used to solubilize myoglobin (Mb). Structural stability of Mb in Phe-IL analyzed using fluorescence and circular dichroism spectroscopy shows that for low levels of hydration of Phe-IL there is a large red shift in the fluorescence emission wavelength and the protein transforms to complete β sheet from its native helical conformation. Rehydration or dilution reverses the β sheet to an α helix which on aging organizes to micrometer-sized fibrils. At concentrations higher than 200 μM, the protein changes from β to a more random coiled structure. Organization of the protein in Phe-IL in a Langmuir film at the air/water interface has been investigated using the surface pressure-molecular area isotherm and shows nearly the same surface tension for both pure Mb and Mb in Phe-IL. Scanning electron microscopy of the films of Mb in Phe-IL transferred using the Langmuir-Blodgett film technique show layered morphology. This study shows that the conformation of Mb is completely reversible going from β → helix → β sheet up to 200 μM of Phe-IL. Similar surface tension values for Mb in water and in Phe-IL suggests that direct ion binding interactions with the protein coupled with the change in local viscosity from the IL seems to not only alter the secondary structure of individual proteins but also drives the self-assembly of the protein molecules leading finally to fibril formation. © 2012 American Chemical Society.

Boopathi S.,CSIR - Central Electrochemical Research Institute | Narayanan T.N.,CSIR - Central Electrochemical Research Institute | Senthil Kumar S.,CSIR - Central Electrochemical Research Institute
Nanoscale | Year: 2014

Though graphitic carbons are commercially available for various electrochemical processes, their performance is limited in terms of various electrochemical activities. Recent experiments on layered carbon materials, such as graphene, demonstrated an augmented performance of these systems in all electrochemical activities due to their unique electronic properties, enhanced surface area, structure and chemical stabilities. Moreover, flexibility in controlling electronic, as well as electrochemical activities by heteroatom doping brings further leverage in their practical use. Here, we study the electron transfer kinetics of fluorinated graphene derivatives, known as fluorinated graphene oxide (FGO) and its reduced form, RFGO. Enhanced electron transfer kinetics (heterogeneous electron transfer (HET)) is observed from these fluorinated systems in comparison to their undoped systems such as graphene oxide (GO) and reduced GO. A detailed study has been conducted using standard redox probes and biomolecules revealing the enhanced electro-catalytic activities of FGO and RFGO, and electron transfer rates are simulated theoretically. This study reveals that fluorine not only induces defects in graphitic lattice leading to an enhanced HET process but also can modify the electronic structure of graphene surface. © 2014 the Partner Organisations.

Prakash R.,CSIR - Central Electrochemical Research Institute | Gogoi S.,CSIR - Central Electrochemical Research Institute
Advanced Synthesis and Catalysis | Year: 2016

The copper(II)-catalyzed decarboxylative coupling reactions of arylglyoxylic acids with isatins afford 4H-benzo[d][1,3]oxazin-4-ones via decarbonylation and concurrent C–N, C–O bond formation. (Figure presented.). © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Remith P.,CSIR - Central Electrochemical Research Institute | Kalaiselvi N.,CSIR - Central Electrochemical Research Institute
Nanoscale | Year: 2014

Novel lithium-rich layered Li1.2Mn0.6Ni0.1Co0.1O2 microspheres containing hierarchically arranged and interconnected nanostructures have been synthesized by a combination of template-free co-precipitation and solid-state methods. The in situ formed γ-MnO2 spherical template upon co-precipitation gets sacrificed during the course of solid-state fusion of cobalt, nickel and lithium precursors to produce the title compound in the form of microspheres constructed by nanoparticles as building blocks. Porous and hollow microspheres of Li1.2Mn0.6Ni0.1Co0.1O2 are formed out of the spontaneous aggregation of nanoparticles, obtained from the custom-designed synthesis protocol. The growth mechanism of Li1.2Mn0.6Ni0.1Co0.1O2 spheres could be understood in terms of the Kirkendall effect and Ostwald ripening. The nanocrystalline Li1.2Mn0.6Ni0.1Co0.1O2 compound is obtained as a solid solution consisting of rhombohedral R3m and monoclinic C2/m group symmetries, as evidenced by XRD, Raman spectra and HRTEM equipped with FFT and STEM. The currently synthesized Li1.2Mn0.6Ni0.1Co0.1O2 cathode exhibits an appreciable discharge capacity of 242 mA h g-1 at a current density of 50 mA g-1, due to the synergistic effect of the capacity obtained from the rhombohedral and monoclinic phases. This journal is © The Royal Society of Chemistry.

Sharma S.,CSIR - Central Electrochemical Research Institute | Singh B.,CSIR - Central Electrochemical Research Institute | Manchanda V.K.,CSIR - Central Electrochemical Research Institute
Environmental science and pollution research international | Year: 2015

Nuclear power reactors are operating in 31 countries around the world. Along with reactor operations, activities like mining, fuel fabrication, fuel reprocessing and military operations are the major contributors to the nuclear waste. The presence of a large number of fission products along with multiple oxidation state long-lived radionuclides such as neptunium ((237)Np), plutonium ((239)Pu), americium ((241/243)Am) and curium ((245)Cm) make the waste streams a potential radiological threat to the environment. Commonly high concentrations of cesium ((137)Cs) and strontium ((90)Sr) are found in a nuclear waste. These radionuclides are capable enough to produce potential health threat due to their long half-lives and effortless translocation into the human body. Besides the radionuclides, heavy metal contamination is also a serious issue. Heavy metals occur naturally in the earth crust and in low concentration, are also essential for the metabolism of living beings. Bioaccumulation of these heavy metals causes hazardous effects. These pollutants enter the human body directly via contaminated drinking water or through the food chain. This issue has drawn the attention of scientists throughout the world to device eco-friendly treatments to remediate the soil and water resources. Various physical and chemical treatments are being applied to clean the waste, but these techniques are quite expensive, complicated and comprise various side effects. One of the promising techniques, which has been pursued vigorously to overcome these demerits, is phytoremediation. The process is very effective, eco-friendly, easy and affordable. This technique utilizes the plants and its associated microbes to decontaminate the low and moderately contaminated sites efficiently. Many plant species are successfully used for remediation of contaminated soil and water systems. Remediation of these systems turns into a serious problem due to various anthropogenic activities that have significantly raised the amount of heavy metals and radionuclides in it. Also, these activities are continuously increasing the area of the contaminated sites. In this context, an attempt has been made to review different modes of the phytoremediation and various terrestrial and aquatic plants which are being used to remediate the heavy metals and radionuclide-contaminated soil and aquatic systems. Natural and synthetic enhancers, those hasten the process of metal adsorption/absorption by plants, are also discussed. The article includes 216 references.

Anandha Ganesh P.,CSIR - Central Electrochemical Research Institute | Jeyakumar D.,CSIR - Central Electrochemical Research Institute
Nanoscale | Year: 2014

For the first time, we are reporting the synthesis of Au100-xPtx nanoporous materials in the size range of 7-10 nm through the galvanic replacement of Ag by Pt from Au100-xAg2x spherical nano-alloys (x = 20, 15, 10 and 5) in an aqueous medium. The galvanic replacement reaction follows the 'Volmer-Weber' growth mode, resulting in the formation of surface bound platinum islands on a nanoporous gold surface. The high angle annular dark field image and low angle X-ray diffraction studies confirm the presence of nanoporous Au100-xPtx NPs. The electrochemical studies using the Au85Pt15/C catalyst show excellent methanol tolerance behaviour and better performance towards oxygen reduction reaction (ORR) in terms of high mass activity, mass-specific activity and figure of merit (FOM) when compared to HiSPEC Pt/C commercial catalyst. Preliminary studies on a full cell using nanoporous Au85Pt15/C (loading 1.0 mg cm-2) as the cathode material and Pt-Ru/C (loading: 0.5 mg cm-2) as the anode material performed better (38 mW cm-2) than the HiSPEC Pt/C cathode material (16 mW cm-2). © 2014 the Partner Organisations.

Parashar G.,Panjab University | Parashar N.C.,CSIR - Central Electrochemical Research Institute | Capalash N.,Panjab University
Molecular and Cellular Biochemistry | Year: 2012

Curcumin and resveratrol were evaluated for their potential to cause reversal of promoter hypermethylation and associated gene expression of FANCF in SiHa cell line. Methylation specific PCR along with bisulphite sequencing revealed the demethylation of 12 CpG sites out of 15 CpG sites spanning +280 to +432 region of FANCF promoter after treatment with curcumin and fivefold up regulation of FANCF gene expression as shown by qRT-PCR. In vitro methylation assay also showed that M.SssI an analogue of DNMT1 was effectively inhibited at 50 μM concentration of curcumin. Resveratrol was not found to be effective in causing reversal of promoter hypermethylation of FANCF gene when used at 20 μM for 4 days in SiHa cell line. © 2012 Springer Science+Business Media, LLC.

Singh H.B.,CSIR - Central Electrochemical Research Institute
Indian Journal of Traditional Knowledge | Year: 2011

This paper reports on a total of 10 plant species of different families which are used as indicators in forecasting weather, in predicting natural calamities, or as taboos or signals of bad omens, among the Meitei community of Manipur state in North eastern India. These plants belong to dicot (6 species), monocot (3 species) and pteridophyte (single species) and are both cultivated (5 species) and grown wildly (rest 5 species). The four species namely, Alocasia indica, Brassica campestris, Hibiscus cannabinus and Mangifera indica are cultivated purely for food purpose while Platycerium wallichi is cultivated as decorative pot plant. The species namely, Quercus serrata in not cultivated in private lands. This knowledge system is still prevalent among the local people, especially in rural areas.

Venkateshwarlu M.,CSIR - Central Electrochemical Research Institute
Journal of Earth System Science | Year: 2015

Magnetic polarity stratigraphy studies were carried out on Jabbar Khad section of Nurpur area, Kangra District, Himachal Pradesh, India. Oriented block samples were collected at 202 sites with 3–5 samples per site from a 2350-m thick continuous sedimentary sequence consisting of sandstone–mudstone alternating beds. Specimens were subjected to thermal demagnetization (100–700°C) after measuring their natural remanent magnetization (NRM). Palaeolatitudes of virtual geomagnetic pole (VGP) from each site were calculated from the acquired characteristic remanent magnetization (ChRM) directions. The observed remanence carrier could be haematite. Magnetic polarity scale (MPS) was erected. This MPS is correlated with the standard geomagnetic polarity time scale (GPTS) of Lourens et al. (2004). The MPS readily matched from chron C2An.1n to chron C4n.2n, therefore assigning an age 8.20–2.60 Ma to the middle and upper Siwalik sections at Nurpur. The rate of sedimentation in middle Siwalik is 29 mm/yr and upper Siwalik is 59 mm/yr. © Indian Academy of Sciences.

Yadav S.K.,CSIR - Central Electrochemical Research Institute | Guleria P.,CSIR - Central Electrochemical Research Institute
Critical Reviews in Food Science and Nutrition | Year: 2012

Stevia rebaudiana, a perennial herb from the Asteraceae family, is known to the scientific world for its sweetness and steviol glycosides (SGs). SGs are the secondary metabolites responsible for the sweetness of Stevia. They are synthesized by SG biosynthesis pathway operating in the leaves. Most of the genes encoding the enzymes of this pathway have been cloned and characterized from Stevia. Out of various SGs, stevioside and rebaudioside A are the major metabolites. SGs including stevioside have also been synthesized by enzymes and microbial agents. These are non-mutagenic, non-toxic, antimicrobial, and do not show any remarkable side-effects upon consumption. Stevioside has many medical applications and its role against diabetes is most important. SGs have made Stevia an important part of the medicinal world as well as the food and beverage industry. This article presents an overview on Stevia and the importance of SGs. © 2012 Copyright Taylor and Francis Group, LLC.

Goswami P.,CSIR - Central Electrochemical Research Institute | Baruah J.,CSIR - Central Electrochemical Research Institute
Meteorology and Atmospheric Physics | Year: 2011

The daily variations in the atmospheric pollutants like suspended particulate matter (SPM), respirable suspended particulate matter (RSPM), sulphur dioxide (SO2) and nitrogen dioxide (NO2) depend on both local meteorological processes and various natural as well as anthropogenic sources and sinks. It was shown in an earlier work (Goswami and Baruah in Mon Wea Rev 136(9):3597-3607, 2008) that the daily variations in SPM over a location could be simulated quite well by considering daily meteorological fields from NCEP Reanalysis in combination with a model for natural and anthropogenic sources over Delhi. In the present work, we extend the scope of the model to include three other pollutants: RSPM, SO2 and NO2. While the basic conservation equations and the meteorological fields are common to all the three (and SPM) pollutants, the sources and sinks for each is modeled in a species-specific manner to obtain maximum skill. As we do not consider active chemistry, the present model provides the minimal dynamics of pollution over an urban location in terms of annual load; the model error is about 10% on the average, with no significant bias for any of the species. © 2010 Springer-Verlag.

Mani D.,CSIR - Central Electrochemical Research Institute | Patil D.J.,CSIR - Central Electrochemical Research Institute | Dayal A.M.,CSIR - Central Electrochemical Research Institute
Chemical Geology | Year: 2011

The stable carbon isotopic compositions of light hydrocarbon gases adsorbed in near-surface soil and sediments from the Saurashtra basin were characterized for their origin and maturity. Saurashtra is considered geologically prospective for oil and gas reserves; however, a major part of the basin is covered by the Deccan Traps, hindering the exploration of Mesozoic hydrocarbon targets. Surface geochemical prospecting, based on micro-seepage of hydrocarbons from subsurface accumulations, could be advantageous in such areas. In light of this, 150 soil samples were collected from the northwestern part of Saurashtra, around the Jamnagar area, where a thick sedimentary sequence of about 2-3km exists under 1-1.5km of Deccan basalt. The concentration of acid desorbed alkane gases from soil samples was found to vary (in ppb) as: methane (C1)=3-518; ethane (C2)=0-430; propane (C3)=0-331; i-butane (iC4)=0-297; n-butane (nC4)=2-116; i-pentane (iC5)=0-31 and n-pentane (nC5)=0-23, respectively.Fifteen samples with high concentrations of alkane gases were measured for their δ13C1; δ13C2 and δ13C3 compositions using gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS). The values for methane varied from -27 to -45.4‰, ethane from -20.9 to -27.6‰, and propane from -20.4 to -29.1‰ versus the Vienna PeeDee Belemnite (VPDB). The carbon isotope ratio distribution pattern represents isotopic characteristics pertaining to hydrocarbon gases derived from thermogenic sources. Comparisons of carbon isotopic signatures and compositional variations with the standard carbon isotopic models suggest that hydrocarbon gases found in the shallow depths of the study area are not of bacterial origin but are formed thermally from deeply buried organic matter, likely to be mainly a terrestrial source rock with a partial contribution from a marine source. These gases may have migrated to the near-surface environment, where they represent an admixture of thermally generated hydrocarbon gases from mixed sources and maturity. The maturity scale (δ13C versus Log Ro %) applied to the surface sediment samples of the Jamnagar area indicated the source material to be capable of generating oil and gas. The detection of thermogenic alkane gases in near-surface sediments offers the possibility of hydrocarbons at depth in Saurashtra. © 2010 Elsevier B.V.

Sarmah M.M.,CSIR - Central Electrochemical Research Institute | Prajapati D.,CSIR - Central Electrochemical Research Institute
Current Organic Chemistry | Year: 2014

Aza heterocycles comprise some rousing structures in biological systems. The aza-Diels-Alder reaction is a [4π+2π] cycloaddition, involving a nitrogen atom in either diene or dienophile or both for the generation of unsaturated N-hexacycles. Although aza- Diels-Alder reaction has made a wonderful journey through different stages of development it is still considered as one of the hot topics of research because of procedural simplicity, high atom economy, regio- and stereoselectivity. Building blocks of many pharmaceutically as well as pharmacologically vital heterocycles have come out as a result of application of aza-Diels-Alder protocol in numerous chemical reactions. This review article describes the state of the art of the aza-Diels-Alder reactions highlighting some of the very first discovery of this pericyclic reaction to most important modern developments. Our discussion is highly focused on awesome versions of aza- Diels-Alder reaction under selected and magnificent catalytic systems and, will provide readers an overview on versatility of this special branch of Diels-Alder reaction towards the creation of a flood of N-containing molecules. © 2014 Bentham Science Publishers.

Mishra D.C.,CSIR - Central Electrochemical Research Institute
Journal of the Geological Society of India | Year: 2011

Most of the Proterozoic basins in India, viz. the Vindhyan, the Cuddapah and the Pakhal Basins have experienced long hiatus between the upper and the lower group of rocks. It is proposed that the older group of rocks of Paleoproterozoic period (∼1.9-1.6 Ga) formed during the rifting phase caused by large scale magmatism in respective basins possibly due to plume tectonics. On the other hand, the younger group of rocks of Neoproterozoic (∼1.0-0.7 Ga) are formed during the final phase of convergence after mountain building that supplied sediments. These geological processes explain large scale disturbances in the older group of rocks during subsequent convergence and collision as they usually occurred along the rifted margins of the cratons. These processes also explain the undisturbed nature, devoid of magmatic rocks of the younger group of rocks and hiatus of about 0.5-0.6 Ga in each case. It is suggested that the plume that was responsible for these rifting of the Indian cratons during Paleo-Mesoproterozoic might have also been responsible for the break up of contemporary Columbian agglomeration in this section. Same model can be used to explain the formation of Proterozoic basins and related hiatus any where else where similar geological environment exist. © 2011 Geological Society of India.

Jeyabharathi C.,CSIR - Central Electrochemical Research Institute | Venkateshkumar P.,CSIR - Central Electrochemical Research Institute | Rao M.S.,CSIR - Central Electrochemical Research Institute | Mathiyarasu J.,CSIR - Central Electrochemical Research Institute | Phani K.L.N.,CSIR - Central Electrochemical Research Institute
Electrochimica Acta | Year: 2012

Nitrogen-doped metal free carbon catalysts were prepared via pyrolysis of polyaniline-coated carbon in different ratios with varying nitrogen content. The surface states and surface composition were investigated using XPS (X-ray photoelectron spectroscopy). XPS analysis confirms the presence of pyridinic and pyrollic nitrogen in the carbon network that is responsible for the oxygen reduction activity. The shift in onset potential of oxygen reduction on C:N (1:1) is ∼0.3 V more positive compared to Vulcan carbon, shows improved activity toward oxygen reduction reaction in acidic electrolyte. Hydrodynamic voltammetric studies confirm that the reduction of oxygen follows the 4e - pathway which leads to the formation of water. © 2012 Elsevier Ltd.

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.

Bhorodwaj S.K.,CSIR - Central Electrochemical Research Institute | Dutta D.K.,CSIR - Central Electrochemical Research Institute
Applied Clay Science | Year: 2011

The esterification of acetic acid with primary (n-), secondary (sec-) and tertiary (ter-) butanol catalyzed by supported heteropoly acids (HPAs), such as dodecatungstophosphoric acid (TPA), dodecatungstosilicic acid (TSA) and dodecamolybdophosphoric acid (MPA) on acid activated Bentonite (AT-GMB) matrix have been carried out. The 20% loaded TPA on AT-GMB showed the highest catalytic activity. The conversions of different alcohols into the corresponding esters decrease in the following order: n-butanol > sec-butanol > ter-butanol. The selectivities for the corresponding esters are nearly 100%. The catalysts were characterized by surface area, thermal analysis, XRD and FTIR spectroscopy. The reusability study shows that the catalysts are stable and active. © 2011 Elsevier B.V.

Singh S.P.,Indian Institute of Chemical Technology | Singh S.P.,CSIR - Central Electrochemical Research Institute | Gayathri T.,Indian Institute of Chemical Technology | Gayathri T.,CSIR - Central Electrochemical Research Institute
European Journal of Organic Chemistry | Year: 2014

Enhancement of light-harvesting efficiency (LHE) in the red/near-IR (NIR) region (600-1000 nm) of the solar spectrum is a challenge to improvement of the photovoltaic performances of dye-sensitized solar cells (DSSCs). Therefore, design and development of effective red/NIR photosensitizers are currently a hot topic in DSSCs. BODIPY dyes can offer magnificent characteristics such as sharp and moderately strong absorption, large quantum yields, long excited state lifetimes, good solubility and easy chromatographic separation. From this perspective, recent progress in BODIPY-sensitized solar cells is reviewed. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Kanungo D.P.,CSIR - Central Electrochemical Research Institute | Sarkar S.,CSIR - Central Electrochemical Research Institute | Sharma S.,CSIR - Central Electrochemical Research Institute
Natural Hazards | Year: 2011

The landslide studies can be categorized as pre- and postdisaster studies. The predisaster studies include spatial prediction of potential landslide zones known as landslide susceptibility zonation (LSZ) mapping to identify the areas/locales susceptible to landslide hazard. The LSZ maps provide an assessment of the safety of existing habitations and infrastructural/functional elements and help plan further developmental activities in the hilly regions. Landslides are one of the natural geohazards that affect at least 15% of land area of India. Different types of landslides occur frequently in geodynamical active domains of the Himalayas. In India, various techniques have been developed and adopted for LSZ mapping of different regions. However, the technique for LSZ mapping is not yet standardized. The present research is an attempt in this direction only. In our earlier work (Kanungo et al. 2006), a detailed study on conventional, artificial neural network (ANN)- black box-, fuzzy set-based and combined neural and fuzzy weighting techniques for LSZ mapping in Darjeeling Himalayas has been documented. In this paper, other techniques such as combined neural and certainty factor concept along with combined neural and likelihood ratio techniques have been assessed in comparison with combined neural and fuzzy technique for the preparation of LSZ maps of the same study area in parts of Darjeeling Himalayas. It is observed from the present study that the LSZ map produced using combined neural and fuzzy approach appears to be the most accurate one as in this case only 2.3% of the total area is found to be categorized as very high susceptibility zone and contains 30.1% of the existing landslide area. This approach can serve as one of the key objective approaches for spatial prediction of landslide hazards in hilly terrain. © 2011 Springer Science+Business Media B.V.

Gahalaut V.K.,CSIR - Central Electrochemical Research Institute
Geomatics, Natural Hazards and Risk | Year: 2011

A strong earthquake (6.9 M w) occurred in the Sikkim-Nepal region of the Himalayan arc which caused the death of about 100 people. The earthquake involved predominantly strike-slip motion on a steep fault, which is transverse to the Himalaya. It implies that the rupture of this earthquake did not occur on the Himalayan detachment, which slips in a stick-and-slip manner to accommodate 2 cm/year of convergence within the Himalaya. Although there is uncertainty about the depth estimates and ambiguity in the fault plane, amongst many other rupture models of the earthquake it is suggested that this, and a similar such earthquake on 20 August 1988 in the Himalayan foothills, occurred in response to the subduction of the Munger-Saharsa ridge on the Indian plate. The occurrence of this earthquake highlights the role of transverse features in the Himalayan tectonics. © 2011 Copyright Taylor and Francis Group, LLC.

Khare P.,CSIR - Central Electrochemical Research Institute | Baruah B.P.,CSIR - Central Electrochemical Research Institute | Rao P.G.,CSIR - Central Electrochemical Research Institute
Tellus, Series B: Chemical and Physical Meteorology | Year: 2011

PM2.5 and PM10 samples collected at a suburban site of northeastern part of India have been analysed for particle mass, total carbon (TC), water-soluble total carbon (WSTC), water-soluble organic carbon (WSOC), water-soluble inorganic carbon (WSIC), organic acids (formic, acetic, proponoic and oxalic acids) along with inorganic ions (NO3 -, SO4 2- and NH4 -). Most of the PM10 consists of PM2.5 in the present site (ratio 54-74%). WSTC content in PM2.5 and PM10 corresponds to 21% and 16%, respectively, of their total particle masses. Thermo gravimetric analysis showed the presence of humic-like substances (16-22%) in particulate samples. Domestic heating and stagnant atmospheric conditions enhanced the levels of these carbonaceous compounds in PM2.5 and PM10 in winter. Qualitative estimation of various functional groups by Fourier transform infrared (FTIR) analysis indicates the presence of carboxylic, hydroxyl, aliphatic and aromatic hydrocarbons, amines and sulphurous compounds in these aerosols. Absolute principal component analysis applied on the aerosol data resolves four factors. These factors are associated with carbonaceous aerosols released from combustion of coal and wood, secondary inorganic and organic aerosols and water-soluble inorganic fraction. © 2011 The Authors Tellus B © 2011 John Wiley & Sons A/S.

Subbalakshmi C.,CSIR - Central Electrochemical Research Institute | Manorama S.V.,Indian Institute of Chemical Technology | Nagaraj R.,CSIR - Central Electrochemical Research Institute
Journal of Peptide Science | Year: 2012

The morphology of structures formed by the self-assembly of short N-terminal t-butyloxycarbonyl (Boc) and C-terminal methyl ester (OMe) protected and Boc-deprotected hydrophobic peptide esters was investigated. We have observed that Boc-protected peptide esters composed of either only aliphatic hydrophobic amino acids or aliphatic hydrophobic amino acids in combination with aromatic amino acids, formed highly organized structures, when dried from methanol solutions. Transmission and scanning electron microscopic images of the peptides Boc-Ile-Ile-OMe, Boc-Phe-Phe-Phe-Ile-Ile-OMe and Boc-Trp-Ile-Ile-OMe showed nanotubular structures. Removal of the Boc group resulted in disruption of the ability to form tubular structures though spherical aggregates were formed. Both Boc-Leu-Ile-Ile-OMe and H-Leu-Ile-Ile-OMe formed only spherical nanostructures. Dynamic light scattering studies showed that aggregates of varying dimensions were present in solution suggesting that self-assembly into ordered structures is facilitated by aggregation in solution. Fourier transform infrared spectroscopy and circular dichroism spectroscopy data show that although all four of the protected peptides adopt well-defined tertiary structures, upon removal of the Boc group, only H-Phe-Phe-Phe-Ile-Ile-OMe had the ability to adopt β-structure. Our results indicate that hydrophobic interaction is a very important determinant for self-assembly and presence of charged and aromatic amino acids in a peptide is not necessary for self-assembly. © 2012 European Peptide Society and John Wiley & Sons, Ltd.

Gupta S.,CSIR - Central Electrochemical Research Institute | Shanker K.,CSIR - Central Electrochemical Research Institute | Srivastava S.K.,CSIR - Central Electrochemical Research Institute
Journal of Pharmaceutical and Biomedical Analysis | Year: 2012

A new validated high-performance thin-layer chromatographic (HPTLC) method has been developed for the simultaneous quantitation of four antipsychotic indole alkaloids (IAs), reserpiline (RP, 1), α-yohimbine (YH, 2), isoreserpiline (IRP, 3) and 10-methoxy tetrahydroalstonine (MTHA, 4) as markers in the leaves of Rauwolfia tetraphylla. Extraction efficiency of the targeted IAs from the leaf matrix with organic and ecofriendly (green) solvents using percolation, ultrasonication and microwave techniques were studied. Non-ionic surfactants, viz. Triton X-100, Triton X-114 and Genapol X-80 were used for extraction and no back-extraction or liquid chromatographic steps were used to remove the targeted IAs from the surfactant-rich extractant phase. The optimized cloud point extraction was found a potentially useful methodology for the preconcentration of the targeted IAs. The separation was achieved on silica gel 60F 254 HPTLC plates using hexane-ethylacetate-methanol (5:4:1, v/v/v) as mobile phase. The quantitation of IAs (1-4) was carried out using the densitometric reflection/absorption mode at 520nm after post chromatographic derivatization using Dragendorff's reagent. The method was validated for peak purity, precision, accuracy, robustness, limit of detection (LOD) and quantitation (LOQ). Method specificity was confirmed using retention factor (R f) and visible spectral (post chromatographic scan) correlation of marker compounds in the samples and standard tracks. © 2012 Elsevier B.V.

Shil A.K.,CSIR - Central Electrochemical Research Institute | Sharma D.,CSIR - Central Electrochemical Research Institute | Guha N.R.,CSIR - Central Electrochemical Research Institute | Das P.,CSIR - Central Electrochemical Research Institute
Tetrahedron Letters | Year: 2012

Solid supported palladium(0) (SS-Pd) catalyzed highly chemoselective reduction of nitroarenes to the corresponding anilines was accomplished under a milder reaction condition. This catalyst showed high compatibility with various reducing agents (NaBH 4, Et 3SiH, and NH 2NH 2·H 2O) and a large number of reducible functional groups such as sulfonamide, amides, carboxylic acid, ester, alcohol, halide, hetero cycle, nitrile, alkene, carbonyl, O-benzyl, and N-benzyl were tolerated. Most of the reactions were clean and high yielding. The SS-Pd catalyst could be recycled up to seven runs without significant loss of activity. © 2012 Elsevier Ltd. All rights reserved.

Khan I.A.,CSIR - Central Electrochemical Research Institute | Saxena A.K.,CSIR - Central Electrochemical Research Institute
Tetrahedron | Year: 2012

The enantiopure non-natural amino acids 1 have been synthesized by insitu generation of iminium and iminium triflates from lactams using triflic anhydride in pyridine buffered media. These molecules with remote chiral centers may be useful in synthesis of natural product particularly Kopsia derived alkaloids. © 2011 Elsevier Ltd. All rights reserved.

Thirunakaran R.,CSIR - Central Electrochemical Research Institute | Ravikumar R.,CSIR - Central Electrochemical Research Institute | Gopukumar S.,CSIR - Central Electrochemical Research Institute | Sivashanmugam A.,CSIR - Central Electrochemical Research Institute
Journal of Alloys and Compounds | Year: 2013

LiMn2O4 and LiZnxWyMn 2-x-yO4 (x = 0.15-0.20; y = 0.10-0.05) powders are synthesized via co-precipitation method using terephthalic acid as chelating agent. The synthesized samples have been subjected to physical studies viz., thermo-gravimetric and differential thermal analysis (TG/DTA), Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), Transmission electron microscopy (TEM) and electrochemical characterization viz., electrochemical galvanostatic cycling studies. Zinc and tungsten doped particles of average 100 nm size are present with clear grain boundaries. Charge-discharge studies show the pristine LiMn2O 4 delivers the discharge capacity of 121 mAhg-1 in the first cycle. Among the investigated dopant concentrations, LiZn 0.15W0.10Mn1.75O4 sample delivers superior performance (120 mAhg-1) with very low capacity fade of 0.84 mAhg-1cycle-1 over the investigated 25 cycles as compared to the undoped and doped spinels and is well accorded with impedance measurements. © 2012 Elsevier B.V. All rights reserved.

Borah P.,CSIR - Central Electrochemical Research Institute | Seetham Naidu P.,CSIR - Central Electrochemical Research Institute | Bhuyan P.J.,CSIR - Central Electrochemical Research Institute
Tetrahedron Letters | Year: 2012

Some novel tetrazole fused pyrido[2,3-c]coumarin derivatives 5/7/9 were synthesized from a one-pot three-component reaction of 4-chloro-3- formylcoumarins 2, sodium azide 3, and alkyl/aryl acetonitriles 4/6/8. © 2012 Elsevier Ltd. All rights reserved.

Mishra A.,CSIR - Central Electrochemical Research Institute | Batra S.,CSIR - Central Electrochemical Research Institute
European Journal of Organic Chemistry | Year: 2010

A straightforward strategy for the synthesis of imidazolefused benzodiazocine from 1-(2-nitrophenyl)-1H-imidazole2-carbaldehyde via Morita-Baylls-Hillman reaction followed by reductive intramolecular cyclization is described. Alternatively the Horner-Wadsworth-Emmons reaction of this substrate with triethyl phosphonoacetate yielded (E)-ethyl 3-(1(2-nitrophenyl)- 1H-imidazol-2-yl)acrylate which upon sequential reduction, saponification and amide coupling furnished imidazole-fused diazocinones. On the other hand, 1(2-nitrophenyl)-1W-pyrrole-2-carbaldehyde failed to undergo the Morita-Baylls-Hillman reaction but successfully yields (B)-ethyl 3-(1-(2-nitrophenyl)-1H-pyrrol-2-yl)acrylate via Horner-Wadsworth-Bmmons reaction which through a similar series of reaction as for imidazole produced pyrrole-fused diazocinone in good yields. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Bindumadhavan K.,Indian Institute of Technology Kharagpur | Srivastava S.K.,Indian Institute of Technology Kharagpur | Mahanty S.,CSIR - Central Electrochemical Research Institute
Chemical Communications | Year: 2013

Molybdenum disulfide (MoS2)-multiwalled carbon nanotube (MWCNT) hybrids have been prepared by simple dry grinding. Excellent initial charge capacity (1214 mA h g-1) and ∼85% retention after 60 discharge-charge cycles at different current densities (100-500 mA g -1) make MoS2-MWCNT (1:1) hybrids a superior anode in Li-ion batteries. © 2013 The Royal Society of Chemistry.

Pulukuri K.K.,CSIR - Central Electrochemical Research Institute | Chakraborty T.K.,CSIR - Central Electrochemical Research Institute | Chakraborty T.K.,Indian Institute of Science
Organic Letters | Year: 2014

Formal synthesis of an actin binding macrolide rhizopodin was achieved in 19 longest linear steps. The key features of the synthesis include a stereoselective Mukaiyama aldol reaction, dual role of a Nagao auxiliary (first, as a chiral auxiliary of choice for installing hydroxy centers and, later, as an acylating agent to form an amide bond with an amino alcohol), late stage oxazole formation, and Stille coupling reactions. © 2014 American Chemical Society.

Krishna Y.,CSIR - Central Electrochemical Research Institute | Sharma S.,CSIR - Central Electrochemical Research Institute | Ampapathi R.S.,CSIR - Central Electrochemical Research Institute | Koley D.,CSIR - Central Electrochemical Research Institute
Organic Letters | Year: 2014

Described here is the design, synthesis, and conformational analysis of cyclic tetrapeptides (CTPs) with α3γ architecture containing a furan-based locked Z-vinylogous amino acid (Vaa). This unnatural amino acid locks into a γ-turn that induces type IαRS- turn in the CTPs. Stabilized by a 13-membered intramolecular H-bond, these CTPs show robust conformation in water and aprotic solvent irrespective of the sequence of tripeptide consisting of α-amino acids used. © 2014 American Chemical Society.

Seetham Naidu P.,CSIR - Central Electrochemical Research Institute | Borah P.,CSIR - Central Electrochemical Research Institute | Bhuyan P.J.,CSIR - Central Electrochemical Research Institute
Tetrahedron Letters | Year: 2012

Some novel functionalized dihydropyrido[2,3-d]pyrimidine derivatives 4 were synthesized using a one-pot three-component reaction of 6-aminouracils 1, aryl aldehydes 2 and 3-cyanoacetyl indole 3 using InCl3 as catalyst. © 2012 Elsevier Ltd. All rights reserved.

Arigela R.K.,CSIR - Central Electrochemical Research Institute | Mandadapu A.K.,CSIR - Central Electrochemical Research Institute | Sharma S.K.,CSIR - Central Electrochemical Research Institute | Kumar B.,CSIR - Central Electrochemical Research Institute | Kundu B.,CSIR - Central Electrochemical Research Institute
Organic Letters | Year: 2012

A rapid one-pot protocol for the synthesis of indole-based polyheterocycles via a sequential Lewis acid catalyzed intermolecular Michael addition and an intramolecular azide/internal alkyne 1,3-dipolar cycloaddition reaction has been described. The generality of the method has been demonstrated by treating a series of aromatic/aliphatic 2-alkynyl indoles with substituted (E)-1-azido-2-(2-nitrovinyl)benzenes to furnish annulated tetracyclic indolo[2,3-c][1,2,3]triazolo[1,5-a][1]benzazepines in good yields. © 2012 American Chemical Society.

Nayak M.,CSIR - Central Electrochemical Research Institute | Batchu H.,CSIR - Central Electrochemical Research Institute | Batra S.,CSIR - Central Electrochemical Research Institute
Tetrahedron Letters | Year: 2012

Straightforward synthesis of a variety of pyrrolo-fused pyrazoles via a cascade reaction between halopyrazolecarbaldehydes and ethylisocyanoacetate in the presence of copper and a base is described. © 2012 Elsevier Ltd. All rights reserved.

Singh V.,CSIR - Central Electrochemical Research Institute | Hutait S.,CSIR - Central Electrochemical Research Institute | Batra S.,CSIR - Central Electrochemical Research Institute
European Journal of Organic Chemistry | Year: 2010

The chemistry of the Morita-Baylis-Hillman adducts of 1formyl-ß- carbolines has been, extended for obtaining indolizino-indole derivatives which mimic the harmicine and homofascaplysin frameworks. Adducts of N-substituted methyl 1formyl-9H-ß-carboline-3-carboxylate yield indolizino-indole derivatives upon bromination followed by aqueous workup. On the other hand, N-substituted l-formyl-9H-ß-carbolines give rise to similar products in a one-pot DABCO-promoted reaction of activated alkenes. Alternatively, the DMAP-mediated Morita-Baylis-Hillman reaction of N-substituted methyl l-formyl-9H-ß-carboline-3-carboxylate with cycloalkenories yields adducts that cyclize intramolecularly in the presence of PBr3 to yield compounds with the homofascaplysin framework. In contrast, the DMAP-mediated reaction of N-substituted l-formyl-ß-carboline with cyclohexenone directly gives a product with similar framework in a single step. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Mayavan S.,CSIR - Central Electrochemical Research Institute | Siva T.,CSIR - Central Electrochemical Research Institute | Sathiyanarayanan S.,CSIR - Central Electrochemical Research Institute
RSC Advances | Year: 2013

Corrosion resistance of iron (Fe) was achieved by coating it with a reduced graphene oxide ink. The Fe surface with the graphene oxide ink coating exhibited improved corrosion resistance in an aggressive chloride environment, which is attributed to the excellent barrier property of graphene. The advantage of this method is that graphene can be deposited by using a solution process that is easy, reproducible, and can be used to coat objects of any dimensions just like conventional paints or coatings. This journal is © The Royal Society of Chemistry.

Ranjan R.,CSIR - Central Electrochemical Research Institute | Ahamad N.,CSIR - Central Electrochemical Research Institute | Ahmed S.,CSIR - Central Electrochemical Research Institute
DNA Repair | Year: 2014

DNA double strand breaks (DSBs) are the most critical types of DNA damage that can leads to chromosomal aberrations, genomic instability and cancer. Several genetic disorders such as Xeroderma pigmentosum are linked with defects in DNA repair. Human Rint1, a TIP1 domain containing protein is involved in membrane trafficking but its role in DNA damage response is elusive. In this study we characterized the role of Drp1 (damage responsive protein 1), a Rint1 family protein during DNA damage response in fission yeast. We identified that Drp1 is an essential protein and indispensable for survival and growth. Using in vitro random mutagenesis approach we isolated a temperature sensitive mutant allele of drp1 gene (. drp1-654) that exhibits sensitivity to DNA damaging agents, in particular to alkylation damage and UV associated DNA damage. The drp1-654 mutant cells are also sensitive to double strand break inducing agent bleomycin. Genetic interaction studies identified that Rad50 and Drp1 act in the same pathway during DNA damage response and the physical interaction of Drp1 with Rad50 was unaffected in drp1-654 mutant at permissive as well as non permissive temperature. Furthermore Drp1 was found to be required for the recovery from MMS induced DNA damage. We also demonstrated that the Drp1 protein localized to nucleus and was required to maintain the chromosome stability. © 2014 Elsevier B.V.

Rajesh N.,CSIR - Central Electrochemical Research Institute | Prajapati D.,CSIR - Central Electrochemical Research Institute
Organic and Biomolecular Chemistry | Year: 2015

A copper catalyzed one-pot, three component reaction between barbituric acid, aldehydes and terminal alkynes has been developed for the construction of pyrano[2,3-d]pyrimidines via a tandem conjugative alkynylation/6-endo cyclization pattern. Screening of barbituric acid derived organic acceptors in conjugative alkynylation reaction and the synthetic applicability of conjugative addition products under one-pot conditions were documented for the first time. © The Royal Society of Chemistry 2015.

Sharma P.,CSIR - Central Electrochemical Research Institute | Das M.R.,CSIR - Central Electrochemical Research Institute
Journal of Chemical and Engineering Data | Year: 2013

In this study, graphene oxide (GO) nanosheets have been used for the adsorption of methyl green, a cationic dye from aqueous solution. GO nanosheets consist of single layered graphite structure decorated with a number of oxygen containing functionalities such as carboxyl, epoxy, ketone, and hydroxyl groups which impart a negative charge density to it in aqueous solution at a wide range of pH. Thus, GO nanosheets can be predicted as a good adsorbent material for the adsorption of cationic species. The adsorption of the methyl green onto the GO nanosheets has been carried out at different experimental conditions such as adsorption kinetics, concentration of adsorbate, pH, and temperature. The kinetics of the adsorption data were analyzed using four kinetic models such as the pseudofirst-order model, pseudosecond-order model, intraparticle diffusion, and the Boyd model to understand the adsorption behavior of methyl green onto the GO nanosheets and the mechanism of adsorption. The kinetics of adsorption result shows that the adsorption maximum was reached at 60 min and follows the linear form of pseudosecond-order kinetics. The adsorption isotherm of adsorption of the methyl green onto the GO nanosheets has been investigated in the pH range of 4 to 9 at 25 C. The equilibrium data were fitted well to the Langmuir model. Various thermodynamic parameters such as the Gibbs free energy (ΔG), enthalpy (ΔH), and entropy (ΔS) change were also evaluated. The negative value of ΔG indicates spontaneity of the adsorption process of the methyl green-GO system. The interaction of methyl green onto the GO nanosheets has been investigated by diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy. © 2012 American Chemical Society.

Brahma K.,CSIR - Central Electrochemical Research Institute | Achari B.,CSIR - Central Electrochemical Research Institute | Chowdhury C.,CSIR - Central Electrochemical Research Institute
Synthesis (Germany) | Year: 2013

An elegant method for the synthesis of 1,2,3-triazoles fused with five-, six-, seven- and eight-membered benzoheterocycles, including isoindoline, tetrahydroisoquinoline, benzoazepine and benzoazocine, has been developed via palladium-copper catalysed reactions in one-pot. The broad scope of this reaction was illustrated by effecting bis-heteroannulations, synthesis of uracil derivatives of biological interest, and employment of acetylene gas as an inexpensive substrate. The reactions are experimentally simple and utilise easily accessible substrates of different types. © Georg Thieme Verlag Stuttgart · New York.

Gogoi S.,CSIR - Central Electrochemical Research Institute | Boruah R.C.,CSIR - Central Electrochemical Research Institute
Synthesis (Germany) | Year: 2013

This work describes a rapid and convenient synthesis of 3,5-disubstituted 2-chloropyridines from various α,β-unsaturated ketoximes utilizing the Vilsmeier reaction under microwave irradiation. The 3,5-disubstituted 2-chloropyridines were further converted into tetrazolo[1,5-a]pyridines by a microwave-mediated solid-phase reaction. The products were isolated in good yields within a very short reaction time. © Georg Thieme Verlag Stuttgart New York.

Kumar A.,CSIR - Central Electrochemical Research Institute | Gupta M.K.,CSIR - Central Electrochemical Research Institute | Kumar M.,CSIR - Central Electrochemical Research Institute | Saxena D.,CSIR - Central Electrochemical Research Institute
RSC Advances | Year: 2013

An efficient micelle promoted one-pot synthesis of 3-amino alkylated indoles has been developed via a three-component Mannich-type reaction from secondary amines, aldehydes and indoles in water under mild reaction conditions. In this Mannich-type reaction, micelles stabilize iminium ions, which undergo a nucleophilic addition of the indole to give 3-amino alkylated indoles in very good yields. © 2012 The Royal Society of Chemistry.

Lakshmi R.V.,CSIR - Central Electrochemical Research Institute | Yoganandan G.,CSIR - Central Electrochemical Research Institute | Kavya K.T.,CSIR - Central Electrochemical Research Institute | Basu B.J.,CSIR - Central Electrochemical Research Institute
Progress in Organic Coatings | Year: 2013

Sol-gel nanocomposite coatings have been investigated for Alclad AA2024 as a potential replacement for the hazardous and banned hexavalent chromate conversion coatings. The sol-gel coatings were prepared using a sol obtained by the hydrolysis and condensation of methyltriethoxysilane and colloidal silica. They were doped with cerium nitrate inhibitor to provide active corrosion protection and were deposited by spray-coating method. The sol-gel process conditions were optimized to obtain smooth and homogenous crack free films. The chemical composition and microstructure of the coatings were studied using EDX and FESEM respectively. The effect of cerium nitrate concentration on the corrosion protection efficiency of the sol-gel coatings was evaluated using potentiodynamic polarization, electrochemical impedance spectroscopy and salt spray tests. The results indicated that cerium nitrate doped coatings were more resistant to corrosion than undoped coating. The coatings doped with 6000 ppm cerium nitrate rendered improved protection after longer immersions due to the inhibitive action of Ce3+. © 2012 Elsevier B.V.

Vasudevan S.,CSIR - Central Electrochemical Research Institute | Lakshmi J.,CSIR - Central Electrochemical Research Institute | Sozhan G.,CSIR - Central Electrochemical Research Institute
Desalination | Year: 2013

The present work provides a critical study on the adsorption of boron by electrochemically generated zinc hydroxide. The various operating parameters on the removal efficiency of boron were investigated, such as initial pH, current density, electrode configuration, inter-electrode distance, co-existing ions and temperature. The results showed that the optimum removal efficiency of 93.2% was achieved at a current density of 0.2A dm-2, at pH of 7.0 with the energy consumption of 1.007kWh m-3. First- and second-order rate equations, Elovich and intraparticle models were applied to study adsorption kinetics. Adsorption isotherms of boron on Zn(OH)2 were determined and correlated with isotherm equations such as Langmuir, Freundlich and D-R models. Thermodynamic parameters, such as standard Gibb's free energy ({increment}Go), standard enthalpy ({increment}Ho), and standard entropy ({increment}So), were also evaluated by Van't Hoff equation. The adsorption process follows second-order kinetics. The adsorption of boron preferably fits with Langmuir adsorption isotherm suggesting monolayer coverage of adsorbed molecules for all current densities and concentration. The adsorption of boron onto Zn(OH)2 was found to be spontaneous and endothermic thermodynamically. © 2012 Elsevier B.V.

Grover S.,CSIR - Central Electrochemical Research Institute | Kukreti R.,CSIR - Central Electrochemical Research Institute
Pharmacogenetics and Genomics | Year: 2014

OBJECTIVE: A considerable heterogeneity exists in the literature on the role of different HLA alleles in carbamazepine (CBZ)-induced cutaneous adverse drug reactions (cADRs) of varying severity among diverse ethnic groups. The aim of the present study was to understand and summarize this heterogeneity and evaluate the contribution of common HLA alleles to susceptibility to cADRs in patients treated with CBZ through a meta-analysis. MATERIALS AND METHODS: A literature search of Embase, Medline, Web of Knowledge, and Cochrane database of systematic reviews was performed up to 28 September 2013. RESULTS: A total of 20 reports were identified as eligible studies, which included 720 CBZ-intolerant [Stevens-Johnson syndrome and toxic epidermal necrolysis (bullous lesions): n=277; hypersensitivity syndrome/maculopapular exanthema (nonbullous lesions): n=359; others: n=84], 1512 CBZ-tolerant, and 1113 normal controls. We observed HLA-A*3101 and HLA-B*1502 as risk markers and HLA-B*4001 as a protective marker for susceptibility to cADRs when comparing intolerant with tolerant patients. Stratification by clinical outcome showed HLA-B*1502 and HLA-B*1511 as risk and HLA-A*2402 as protective markers for bullous lesions in the Asians [HLA-B*1502: odds ratio (OR)=80.70; 95% confidence interval (CI)=45.62-142.77; P=1.8×10; I=33%, HLA-B*1511: OR=17.43; 95% CI=3.12-97.40; P=1.1×10; I=0%, HLA-A*2402: OR=0.27; 95% CI=0.11-0.64; P=2.7×10; I=0%]. Furthermore, HLA-A*3101 was observed to be a universal risk marker, irrespective of cADR type [OR (bullous lesions)=5.65; 95% CI =2.70-11.78; P=4.03×10; I=49%, OR (nonbullous lesions)=8.58; 95% CI=5.55-13.28; P=4.46×10; I=0%]. Sensitivity analysis showed HLA-B*4001 as a protective marker in Chinese population for showing bullous lesions (OR=0.14; 95% CI=0.06-0.32; P=3.2×10; I=0%). CONCLUSION: In summary, our meta-analysis showed the presence of HLA alleles contributing toward risk of as well as protection against various CBZ-induced cADRs. © 2014 Wolters Kluwer Health Lippincott Williams & Wilkins.