Sudipta Biswas - Academia.edu (original) (raw)

Papers by Sudipta Biswas

Tuning Na2Ti3O7 Nanostructures for Tailoring High-Performance Na-Ion Supercapacitors

Energy & Fuels

Improper footwear has been attributed to poor fitting with discomfort, and resulting the ultimate... more Improper footwear has been attributed to poor fitting with discomfort, and resulting the ultimate major foot defects. Previous studies on footwear have investigated the effect of material composition, sole stiffness and thickness, heel height, motion etc. and minute amount is known regarding the effects of toe profile variation on forefoot. In consequence, the aim of this study is to investigate the impact of different toe shapes with different shoe sizes on foot bone alignment. An adult male as convenience subject with unknown foot difficulties was recruited for the study. After assessment of foot size and other associated demographic information, anteroposterior view of the participant’s foot was captured for each of the nine different footwear as well as barefoot condition. Data like hallux valgus angle (HVA), intermetatarsal angle (IMA), and hallux valgus interphalangeal angle (HVIPA) were collected from the radiographs and analyzed as well. Shoes with plain toe and smaller size...

Tribal Land Rights: A Situational Analysis in the Context of West Bengal

Journal of Land and Rural Studies, 2020

Tribal communities in India are most deprived. Socio-economically, they are poor and marginalised... more Tribal communities in India are most deprived. Socio-economically, they are poor and marginalised. The root cause of socio-economic marginalisation can be attributed to alienation of tribal people from their land, territory and resources. The overall situation of the tribal population of West Bengal is not better than the national average, even more deprived than the tribal population of other states. Despite progressive land reform laws and political commitment to implement such laws, issues of tribal land rights have not been addressed adequately. There is no such exclusive study to understand the situation of tribal land rights in the state of West Bengal. This article analyses the status of tribal land rights in the state context and makes some suggestions for improving the situation. It is found that despite distribution of land titles, a large section of the tribal population remains landless. A sizable portion has not received received record-of-rights. Claims of many tribal ...

Over the last several years, capabilities to simulate the progression and effects of degradation ... more Over the last several years, capabilities to simulate the progression and effects of degradation in critical structures in light water reactor (LWR) nuclear power plants have been under development in the Grizzly code. Age-related material degradation is important for a number of systems in LWRs, but the main focus for Grizzly development has been on reactor pressure vessels (RPVs) and concrete structures because of their central role and the difficulty of replacement of these structures if they are found to be degraded to an unacceptable degree. The capabilities for analyzing both RPVs and concrete structures in Grizzly have reached a point where the feature sets are sufficiently complete to perform credible analyses of those types of structures. Because of this, the emphasis has shifted from foundational development to assessing the accuracy of these modeling capabilities on representative problems of interest and on improving the physical basis of those models to improve their ability to predict the actual response of those structural systems. This report documents a first set of test cases that have been developed to assess the Grizzly code on real-world problems for these two types of structures. For RPVs, these test cases consist of a set of benchmark problems where Grizzly is compared to another code. For concrete structures, a set of models of experimental specimens designed to characterize the multidimensional swelling response of reinforced concrete members due to alkali-silica reaction (ASR) has been developed and compared with experimental results. Both the RPV and concrete test cases developed here are much more computationally intensive than the small regression tests that are used in the testing that Grizzly undergoes every time a proposed set of changes is made to ensure that those changes do not adversely affect previously established behavior. A system for regularly running these large problems to monitor the behavior of the code as it is developed has been instituted. While these test cases generally indicate good comparison with the benchmark results, they also indicate areas where further development is warranted.

International Journal of Advances in Scientific Research, 2016

The Indian fresh water eel, Mastacembelus pancalus (Ham) was chronically exposed to lead nitrate ... more The Indian fresh water eel, Mastacembelus pancalus (Ham) was chronically exposed to lead nitrate for 30 days exposed at dose of LC20 value (in respect to 925ppm 96-h LC50 value). Results show reduced fecundity and GSI and deteriorated ootoxic conditions. Oolytic alteration includes lesion of oocytes, which resulted in dearth of any interfollicular spaces. Distorted appearance of oocytes was a major alteration observed. No distinct follicular normal histology was seen and also usual ovular conditions on the whole been lost. The effects of chronic exposure on growth and reproduction parameters were investigated in M. pancalus. The study demonstrated that toxic heavy metal lead can cause reproductive defect in fishes. Present study insured that the growth of body weight and gonadal development along with egg laying capacity that is the fecundity and histological alteration of ovary of Mastacembelus pancalus is noticeably changed after 30 days exposure of lead nitrate. Lead exposure and...

Facile synthesis of asymmetric patchy Janus Ag/Cu particles and study of their antifungal activity

Frontiers of Materials Science, 2020

Asymmetric patchy Ag/Cu Janus nanoparticles (NPs) were synthesized via a “seed-mediated” approach... more Asymmetric patchy Ag/Cu Janus nanoparticles (NPs) were synthesized via a “seed-mediated” approach. This is the first report of synthesis of nanometer sized metal-based Janus NPs without using complicated methods. Selective adsorption of the surfactant onto the seed NPs leads to the formation of Janus type structure. Subsequently the reduction potential of Ag + /Ag 0 and Cu 2+ /Cu 0 systems directs the formation of the “patch”. The patchy Janus NPs show significant antifungal activity towards a potent rice pathogen thus offering the prospect of future application in crop protection.

Circulation Research, 2017

Rationale: Platelet hyperreactivity, which is common in many pathological conditions, is associat... more Rationale: Platelet hyperreactivity, which is common in many pathological conditions, is associated with increased atherothrombotic risk. The mechanisms leading to platelet hyperreactivity are complex and not yet fully understood. Objective: Platelet hyperreactivity and accelerated thrombosis, specifically in dyslipidemia, have been mechanistically linked to the accumulation in the circulation of a specific group of oxidized phospholipids (oxPC CD36 ) that are ligands for the platelet pattern recognition receptor CD36. In the current article, we tested whether the platelet innate immune system contributes to responses to oxPC CD36 and accelerated thrombosis observed in hyperlipidemia. Methods and Results: Using in vitro approaches, as well as platelets from mice with genetic deletion of MyD88 (myeloid differentiation factor 88) or TLRs (Toll-like receptors), we demonstrate that TLR2 and TLR6 are required for the activation of human and murine platelets by oxPC CD36 . oxPC CD36 induc...

Frontiers in Materials, 2019

Single phase NaFePO 4 can works as economically viable cathode material for Na-systems similar to... more Single phase NaFePO 4 can works as economically viable cathode material for Na-systems similar to LiFePO 4-a material that led to the commercialization of Li-ion based energy systems. The reported microstructures of hollow NaFePO 4 particles, with porous walls, establish their advantages over solid morphologies. The hollow structures deliver stable electrochemical specific capacitance of 115 F g −1 in 2 M NaOH electrolyte, over a large number of cycles. This observation is directly attributed to the increased surface area, transport channels and redox sites, which become available in the porous-hollow particles. Hitherto unreported electrochemical performance under non-ambient environment is also discussed. In contrast to recently reported in Fe-based metal oxides, where significant change in specific capacitance has been reported as a function of magnetic field, it is observed that NaFePO 4 can protect itself and suppress modifications. More importantly, NaFePO 4 can work as an efficient electrode material in the temperature range RT to 65 • C, which makes it useful for automotive industry.

Advanced Energy Materials, 2018

A simple question, which remains ignored in the field of supercapacitors is: will the device perf... more A simple question, which remains ignored in the field of supercapacitors is: will the device performance be affected near a magnetic field, if it is fabricated using electrode materials that are also magnetic? It is shown in this paper that the answer is: yes, it will be appreciably affected! The modulation in the specific capacitance is a convoluted picture of variation: diffusion mechanics of solvated cations, Nernst layer at the interface, magnetoresistance, and associated I–V response. The magnetic field also has direct control on the value at which saturation in specific capacitance is observed in such devices. Nearly a 170% increase in energy density at 1 A g−1 is observed by varying the magnetic field from 0 to 5 mT and a ten fold increase in power density is observed at 5 mT when current density is increased from 1 to 5 A g−1. These results clearly show that electronic circuitry designed using supercapacitors needs to be reworked/designed if it is to be used in or around mag...

Journal of Nanoelectronics and Optoelectronics, 2017

In this work, we investigate the transport phenomena in III-V material based buried channel Quant... more In this work, we investigate the transport phenomena in III-V material based buried channel Quantum Well MOSFET with a view to develop a simple and effective model for the device current. Device simulation has been performed in quantum ballistic regime using non equilibrium Green's function (NEGF) formalism. The simulated I-V characteristics using a novel concept of effective transmission coefficient has been found to define the reported experimental data with high accuracy. The proposed model has also been effective to capture the transport characteristics reported for other III-V material based field effect transistors. The concept of the proposed effective transmission coefficient and hence the model lends itself to be a simple and powerful device analysis tool which can be extensively used to predict the performance of a wide variety of compound semiconductor devices in the pre-fabrication stage. It has also demonstrated consistency with device characteristics for doping concentration and channel length scaling. Thus the model can help the device/process engineers to tune the devices for the best possible performance.

ACS Nano, 2015

Foremost among the challenges facing single molecule sequencing of proteins by nanopores is the l... more Foremost among the challenges facing single molecule sequencing of proteins by nanopores is the lack of a universal method for driving proteins or peptides into nanopores. In contrast to nucleic acids, the backbones of which are uniformly negatively charged nucleotides, proteins carry positive, negative and neutral side chains that are randomly distributed. Recombinant proteins carrying a negatively charged oligonucleotide or polypeptide at the Ctermini can be translocated through a α-hemolysin (α-HL) nanopore, but the required genetic engineering limits the generality of these approaches. In this present study, we have developed a chemical approach for addition of a charged oligomer to peptides so that they can be translocated through nanopores. As an example, an oligonucleotide PolyT 20 was tethered to peptides through first selectively functionalizing their N-termini with azide followed by a click reaction. The data show that the peptide-PolyT 20 conjugates translocated through nanopores whereas the unmodified peptides did not. Surprisingly, the conjugates with their peptides tethered at the 5′-end of PolyT 20 passed the nanopores more rapidly than the PolyT 20 alone. The PolyT 20 also yielded a wider distribution of blockade currents. The same broad distribution was found for a conjugate with its peptide tethered at the 3′-end of PolyT 20 , suggesting that the larger blockades (and longer translocation times) are associated with events in which the 5′-end of the PolyT 20 enters the pore first.

Contact manifolds isometrically immersed in a manifold of constant curvature

Circulation research, Jan 31, 2015

Oxidative stress is an important contributing factor in several human pathologies ranging from at... more Oxidative stress is an important contributing factor in several human pathologies ranging from atherosclerosis to cancer progression; however, the mechanisms underlying tissue protection from oxidation products are poorly understood. Oxidation of membrane phospholipids, containing the polyunsaturated fatty acid docosahexaenoic acid, results in the accumulation of an end product, 2-(ω-carboxyethyl)pyrrole (CEP), which was shown to have proangiogenic and proinflammatory functions. Although CEP is continuously accumulated during chronic processes, such as tumor progression and atherosclerosis, its level during wound healing return to normal when the wound is healed, suggesting the existence of a specific clearance mechanism. To identify the cellular and molecular mechanism for CEP clearance. Here, we show that macrophages are able to bind, scavenge, and metabolize carboxyethylpyrrole derivatives of proteins but not structurally similar ethylpyrrole derivatives, demonstrating the high s...

The object of the present paper is to study LP-Sasakian manifolds satisfying certain conditions.

Facile synthesis of luminescent TiO2 nanorods using an anionic surfactant: Their photosensitization and photocatalytic efficiency

Materials Chemistry and Physics, 2014

Mixed phase (rutile/anatase)TiO2 nanorods have been synthesized using an anionic surfactant templ... more Mixed phase (rutile/anatase)TiO2 nanorods have been synthesized using an anionic surfactant template. Nanorod synthesis has been achieved using mild reaction conditions and without using any rod-shaped template. The shape and crystallinity of the TiO2 nanomaterials can be modulated by careful control of the surfactant concentration. The novelty of the present work is that the anatase/rutile mixed phase nanorods were formed without using the well-known layer by layer assembly method or the hydrothermal method. These mixed phase TiO2 nanorods are highly luminescent, can be easily sensitized by fluorescent dyes, show significant dye adsorption ability and function as efficient photocatalysts. (C) 2014 Elsevier B.V. All rights reserved.

Bull. Malays. Math. Sci. Soc.(2), 2006

BULLETIN of the Malaysian Mathematical Sciences Society http://math.usm.my/bulletin ... A Note on... more BULLETIN of the Malaysian Mathematical Sciences Society http://math.usm.my/bulletin ... A Note on ξ-Conformally Flat Contact Manifolds ... UC De and Sudipta Biswas Department of Mathematics, University of Kalyani, Kalyani – 741235, West Bengal, India ucde@klyuniv. ...

Journal of Mathematics, Novi Sad, 2003

In 1977, T. Takahashi [2] introduced the notion of locally φ–symmetric Sasakian manifolds and stu... more In 1977, T. Takahashi [2] introduced the notion of locally φ–symmetric Sasakian manifolds and studied their several interesting properties. In this paper we introduce the notion of φ–recurrent Sasakian manifolds which generalizes the notion of locally φ–symmetric ...

PLoS ONE, 2013

Oxygen sensing transcription factor HIF-1 is activated due to accumulation of regulatory subunit ... more Oxygen sensing transcription factor HIF-1 is activated due to accumulation of regulatory subunit HIF-1a by posttranslational stability mechanism during hypoxia or by several other stimuli even in normoxia. HIF-1a is also regulated by NF-kB mediated transcription mechanism. Reactive oxygen species (ROS) act as an important regulator of HIF-1 either by affecting prolyl hydroxylase activity, the critical determinant of HIF-1a stabilization or by activating NF-kB to promote HIF-1a transcription. Insulin is known to activate HIF-1 by a ROS dependent mechanism but the molecular mechanism of HIF-1a regulation is not known so far. Here we show that insulin regulates HIF-1a by a novel transcriptional mechanism by a ROSsensitive activation of Sp1 in 3T3-L1 preadipocyte. Insulin shows little effect on HIF-1a protein stability, but increases HIF-1a promoter activity. Mutation analyses, electrophoretic mobility shift assay and chromatin immunoprecipitation assay confirm the role of Sp1 in HIF-1a transcription. We further demonstrate that insulin-induced ROS generation initiates signaling pathway involving phosphatidylinositol 3-kinase and protein kinase C for Sp1 mediated HIF-1a transcription. In summary, we reveal that insulin regulates HIF-1a by a novel transcriptional mechanism involving Sp1.

PLoS ONE, 2012

Recent evidence established a crucial role for mammalian oxygen sensing transcription factor hypo... more Recent evidence established a crucial role for mammalian oxygen sensing transcription factor hypoxia inducible factor-1 (HIF-1) in innate immunity against intracellular pathogens. In response to most of these pathogens host phagocytes increase transcription of HIF-1a, the regulatory component of HIF-1 to express various effector molecules against invaders. Leishmania donovani (LD), a protozoan parasite and the causative agent of fatal visceral leishmaniasis resides in macrophages within mammalian host. The mechanism of HIF-1 activation or its role in determining the fate of LD in infected macrophages is still not known. To determine that J774 macrophages were infected with LD and about four-fold increase in HIF-1 activity and HIF-1a expression were detected. A strong increase in HIF-1a expression and nuclear localization was also detected in LD-infected J774 cells, peritoneal macrophages and spleen derived macrophages of LDinfected BALB/c mice. A twofold increase in HIF-1a mRNA was detected in LD-infected macrophages suggesting involvement of a transcriptional mechanism that was confirmed by promoter activity. We further revealed that LD also induced HIF-1a expression by depleting host cellular iron pool to affect prolyl hydroxylase activity resulting in to stabilization of HIF-1a. To determine the role of HIF-1 on intracellular LD, cells were transfected with HIF-1a siRNA to attenuate its expression and then infected with LD. Although, initial infection rate of LD in HIF-1a attenuated cells was not affected but intracellular growth of LD was significantly inhibited; while, over-expression of stabilized form of HIF-1a promoted intracellular growth of LD in host macrophage. Our results strongly suggest that LD activates HIF-1 by dual mechanism for its survival advantage within macrophage.