Central University of Jharkhand

Ranchi, India

The Central University of Jharkhand is a Central University of India, established by an act of Indian Parliament in 2009. The President of India assented this act on 20 March 2009, however the university act deemed to come into force on 15 January 2009. Like other Central Universities of India it is a teaching and research university. Wikipedia.

Time filter
Source Type

Kuila B.K.,Central University of Jharkhand | Chakraborty C.,Indian Association for The Cultivation of Science | Malik S.,Indian Association for The Cultivation of Science
Macromolecules | Year: 2013

Here, we investigate a synergistic coassembly of a block copolymer, polystyrene-b-poly(4-vinylpyridine) (PS-b-P4VP), and a fluorescent probe molecule, pyrenebutyric acid (PBA), in thin film using block copolymer supramolecular assembly (SMA) strategy for a wide range of compositions tuned by varying the molar ratio (r) of PBA and 4VP units. The PBA molecules form supramolecules with PS-b-P4VP through H-bonding between the carboxylic acid group of 1-pyrenebutyric acid and pyridine ring of P4VP. For compositions r = 0, 0.1, 0.25, and 0.5, the SMAs exhibit cylindrical morphology, whereas for r = 0.75 and 1, the SMAs generate lamellar morphology. Interestingly, it has been observed that the orientation of the microdomains depends on the solvent used for annealing and can be switched reversibly on exposing the SMA films to corresponding solvent. In a nonselective solvent like chloroform, the microdomains are oriented normal to the substrate, whereas in a selective solvent like 1,4-dioxane, the microdomains are oriented parallel. The synergistic coassembly of PS-b-P4VP and PBA in SMAs with higher molar ratio results in a structure-within-structure pattern characterized by two length scales from phase separation of block copolymer and parallel π-π stacking of the pyrene moiety of PBA molecules inside the comb block. The photophysical properties of PBA in different SMAs of varying composition were studied both in solution and in thin film state and compared to pure PBA. The UV-vis study shows the H type of aggregation of PBA molecules inside the comb block by parallel stacking of the pyrene units, and the PBA molecules orient parallel to the substrate when the microdomains are oriented normal to the substrate. The pure PBA molecules in thin film exhibit excimer emission extensively, whereas the PBA molecules in different supramolecular assemblies exhibit emission ranging from monomer to mixture of monomer and excimer. The SMA shows more intense fluorescence emission compared to pure PBA both in solution and in thin film. © 2012 American Chemical Society.

Mishra R.,Central University of Jharkhand | Nagini S.,Annamalai University | Rana A.,Loyola University Chicago
Molecular Cancer | Year: 2015

Background: The study aims to evaluate the expression and activity of glycogen synthase kinase 3 isoforms α/β (GSK3α/β) and to assess their oncogenic potential through a correlation with the expression of cyclin D1 and p53 in oral cancer. Methods: The expression of total and phosphorylated GSK3α/β as well as cyclin D1 and p53 together with their interaction were assessed in human oral cancer tissue samples, apparently normal adjacent tissues, benign tumor samples, premalignant lesions and healthy normal tissues (total 179) using various methods, such as immunohistochemistry, Western blot assays, immunoprecipitation and RT-PCR analysis. Results: The expression of GSK3β was significantly higher relative to GSK3α indicating the greater role of the β isoform in oral cancer. Among various types of oral cancers, OSCC (of the lip and tongue) showed elevated expression of GSK3α/β, and the expression was correlated with disease progression. The increased expression of pS21GSK3α and pS9GSK3β not only correlated positively with cyclin D1 and p53 expression in tongue cancer progression but a gradual shift of their expression from the cytoplasmic to the nuclear compartment and overall disease severity was also observed. The interaction of GSK3β-cyclin D1 and the positive correlation of pS9GSK3β and the transcription of cyclin D1 were observed. Conclusions: These results demonstrate that the inactivation of GSK3β is an important event in OSCC and can be used as a marker for assessing disease severity and may be exploited for therapeutic intervention. © Mishra et al.

Mishra R.,Central University of Jharkhand
Oral Oncology | Year: 2012

Oral cancer is the sixth most common form of cancer worldwide, and the majority of cases occur in India and Southeast Asia. Its major risk factors in the western world include smoking and drinking alcohol, whereas in Asia, it is primarily caused by tobacco/areca nut/betel leaf chewing and/or human papillomavirus (HPV) infections. Little is known about this type of cancer despite recent advances in cancer biology. The generally asymptomatic nature of the early oral lesions causes them to remain undetected in many cases. Thus, the disease progresses substantially before the patients seek treatment and is a major contributing factor to the severity of this disease. Therefore, there is a great need to create awareness for its prevention and early diagnosis. The application of advanced molecular biological and biochemical methodologies to elucidate its biomarkers may aid in early detection; however, much more work must be done for this information to be effectively applied in the clinical setting. This review focuses on the need for systematic diagnoses in the early detection of oral cancer using molecular and biochemical approaches, thereby reducing the number of advanced cases in the chewing tobacco-dominated oral cancer population. © 2012 Elsevier Ltd. All rights reserved.

Ramchiary A.,Tezpur University | Samdarshi S.K.,Central University of Jharkhand
Applied Surface Science | Year: 2014

Photocatalyst nanoparticles of Ag deposited anatase titania with plasmonic junction and mixed phase titania with homo-junction were prepared and their physico-chemical characterization was done using different analytical techniques. Their photocatalytic performance in visible light was found to be comparable albeit ascribable to different junction characteristics with identical consequences in terms of photoactivity. It has been shown that co-junction of the combination of both in plasmonic Ag nanoparticle deposited mixed phase titania has a multiplying effect and yields a superior visible light photocatalyst. The combination showed 3.4 times more activity than the two in isolation in degradation of methylene blue. Standard photocatalyst Degussa P25 (DP25) is also used as a reference catalyst to compare the photoactivity. © 2014 Elsevier B.V.

Ramchiary A.,Tezpur University | Samdarshi S.K.,Central University of Jharkhand
Chemical Physics Letters | Year: 2014

The hydrogenation induced band-edge tailing with the resultant red-shift in the absorption spectrum and the creation of oxygen vacancies have incredible impact on the functionality of the monophasic titania photocatalyst in detoxification of aqueous pollutant under solar radiation. The mixed phase titania with optimum phase ratio consistently shows high activity in UV and/or visible radiation flux due to efficient separation of photo-generated charge carriers. We demonstrate that the hydrogenation of mixed phase titania (anatase-to-rutile ratio = 0.67) shows 15 times higher photocatalytic activity in the degradation of aqueous probe pollutant under the visible light, than the non-hydrogenated Degussa P25 catalyst. © 2014 Published by Elsevier B.V.

Das D.,Central University of Jharkhand | Mohapatra S.S.,Indian Institute of Technology Bhubaneswar | Roy S.,Indian Institute of Technology Bhubaneswar
Chemical Society Reviews | Year: 2015

Heterobimetallic catalysts, bearing a metal-metal bond between a transition metal (TM) and a tin atom, are very promising due to their ability in mediating a wide variety of organic transformations. Indeed the utilization of such catalysts is a challenging and evolving area in the field of homogeneous catalysis. Catalysis across a 'TM-Sn' motif is an emerging area in the broader domain of multimetallic catalysis. The present review apprises the chemists' community of the past, present and future scope of this versatile catalytic motif. The TM-Sn catalyzed reactions presented include, among others, Friedel-Crafts alkylation, carbonylation, polymerization, cyclization, olefin metathesis, Heck coupling, hydroarylation Michael addition and tandem coupling. The mechanistic aspects of the reactions have been highlighted as well. © The Royal Society of Chemistry 2015.

Mishra R.,Central University of Jharkhand
Oral Oncology | Year: 2013

Oral cancer is a growth-related disorder, and cyclins are the prime regulators of cell division. Cyclins are associated with the pathogenesis of oral cancer and are considered valuable biomarkers for diagnosis and prognosis. These important molecules are regulated in many ways to achieve a gain in function and are involved in promoting neoplastic growth. While the causes of most cyclin overexpression are varied, these cyclins may be induced by buccal mucosal insult mainly with carcinogens that alter various pathways propelling oral cancer. Substantial experimental evidences support a link between oncogenic signaling pathways and the deregulation of cyclins in oral cancer. This review focuses on the mechanisms by which cyclins are regulated and promote oral oncogenesis. © 2013 Elsevier Ltd. All rights reserved.

Rajbongshi B.M.,Tezpur University | Samdarshi S.K.,Central University of Jharkhand
Materials Science and Engineering B: Solid-State Materials for Advanced Technology | Year: 2014

Enhancement in photoactivity of zinc oxide, a UV active photocatalyst, can be achieved through nanostructuration in addition to doping induced red-shift in absorption spectrum. For this, nanorods of cobalt-doped-ZnO (Co-ZnO) were synthesized by hydrothermal method. As expected, Co-ZnO nano-rods showed high photocatalytic activity in degradation of methylene blue dye (MB) and phenol under visible radiation flux compared to pristine ZnO nano-rods, synthesized identically. XRD, SEM, TEM, EDX, UV-DRS, PL and FTIR studies were used to characterize the photocatalysts. ZnO and Co-ZnO, both had wurtzite phase of ZnO with nano-rod morphology having length:diameter of 440 nm:120 nm and 1460 nm:162 nm, respectively. Surprisingly, under UV light the ZnO-nanorods showed more activity than Co-ZnO. These contrasting results, when correlated with dopant-induced quenching of oxygen vacancies, indicated toward complementary role of oxygen vacancy in the photoactivity of the materials with the dominant role of band gap-assisted red-shift in the absorption spectrum. © 2013 Elsevier B.V.

Verma R.,Tezpur University | Samdarshi S.K.,Central University of Jharkhand
Journal of Alloys and Compounds | Year: 2015

The photocatalytic activity is a result of the synergy of a succession of phenomena-photogeneration, separation, and participation of the charge carriers in redox reaction at the catalyst surface. While the extent of photogeneration is assessable in terms of absorption spectrum (band gap), the redox reaction can be correlated to specific surface area. However the respective change in the photocatalytic activity has not been rationally and consistently correlated with the above mentioned parameters. A satisfactory explanation of suppression of recombination based on separation of carriers due to differential mobility/diffusivity in the material phase(s) and/or intrinsic potential barrier exists but its correlation with common identifiable parameter/characteristics is still elusive. This paper attempts to address this issue by correlating the carrier separation with the phase ratio (phase interface) in mixed phase titania and generalizing it with the presence of oxygen vacancy at the phase interface. It essentially appears to complete the quest for identifiable parameters in the sequence of phenomena, which endow a photocatalyst with an efficient activity level. It has been done basically using photoluminescence; X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy in addition to other characterization tools such as X-ray diffraction (XRD), transmission electron microscope (TEM), UV-Vis absorption (UV-Vis DRS), and Fourier transform infrared (FTIR) studies. © 2015 Elsevier B.V. All rights reserved.

Kuila B.K.,Leibniz Institute of Polymer Research | Kuila B.K.,Central University of Jharkhand | Stamm M.,Leibniz Institute of Polymer Research
Journal of Materials Chemistry | Year: 2011

Supramolecular assembly (SMA) of block copolymer and small molecule has received enormous research interest for its applications in high resolution surface patterning of different functional nanomaterials at different length scales. The patternability of block copolymer supramolecular system results from its ability to self-assemble into a wide range of periodic structures in nanoscopic length scale. The advantages of using supramolecular system over the pure block copolymer are easy tuning of morphology by changing the small molecule composition, introduction of new functionality into the block copolymer layer by using non-covalent interaction and simple removal of the minor component by dissolution from the block copolymer layer to transform it into a porous nanotemplate. In the last few years, our group has extensively studied block copolymer-small molecule supramolecular assembly in thin film and developed some novel SMA systems mostly with an aim to fabricate polymer nanotemplates for further surface patterning with various functional nanomaterials. In this feature article, we will discuss these recent developments in creating such patterns of various functional nanomaterials using block copolymer supramolecular assembly. © 2011 The Royal Society of Chemistry.

Loading Central University of Jharkhand collaborators
Loading Central University of Jharkhand collaborators