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41.
Plasmonics - Spectral feature of gold nanowires-based hyperbolic metamaterial (NWHMM) absorber was investigated. The absorber has NWHMM surface as the top layer, which is composed of periodically... 相似文献
42.
Yue Deng Jingxu Zheng Alexander Warren Jiefu Yin Snehashis Choudhury Prayag Biswal Duhan Zhang Lynden A. Archer 《Liver Transplantation》2019,9(39)
Metallic sodium is receiving renewed interest as a battery anode material because the metal is earth‐abundant, inexpensive, and offers a high specific storage capacity (1166 mAh g?1 at ?2.71 V vs the standard hydrogen potential). Unlike metallic lithium, the case for Na as the anode in rechargeable batteries has already been demonstrated on a commercial scale in high‐temperature Na||S and Na||NiCl2 secondary batteries, which increases interest. The reversibility of room temperature sodium anodes is investigated in galvanostatic plating/stripping reactions using in situ optical visualization and galvanostatic polarization measurements. It is discovered that electronic disconnection of mossy metallic Na deposits (“orphaning”) is a dominant source of anode irreversibility in liquid electrolytes. The disconnection is shown by means of direct visualization studies to be triggered by a root‐breakage process during the stripping cycle. As a further step toward electrode designs that are able to accommodate the fragile Na deposits, electrodeposition of Na is demonstrated in nonplanar electrode architectures, which provide continuous and morphology agnostic access to the metal at all stages of electrochemical cycling. On this basis, nonplanar Na electrodes are reported, which exhibit exceptionally high levels of reversibility (Coulombic efficiency >99.6% for 1 mAh cm?2 Na throughput) in room‐temperature, liquid electrolytes. 相似文献
43.
Garsa Anita Kumari Choudhury Prasanta Kumar Puniya Anil Kumar Dhewa Tejpal Malik Ravinder Kumar Tomar Sudhir Kumar 《Probiotics and antimicrobial proteins》2019,11(4):1403-1413
Probiotics and Antimicrobial Proteins - Bovicin is a type AII lantibiotic, possessing two β-methyllanthionine and a disulfide bridge encoded by bovA gene hitherto unknown a couple of decades... 相似文献
44.
Banerjee S Mirsamadi N Anantharaman L Sivaram MV Gupta RB Choudhury D Roy RP 《The protein journal》2007,26(7):445-455
The identity of intermolecular contact residues in sickle hemoglobin (HbS) fiber is largely known. However, our knowledge
about combinatorial effects of two or more contact sites or the mechanistic basis of such effects is rather limited. Lys16,
His20, and Glu23 of the α-chain occur in intra-double strand axial contacts in the sickle hemoglobin (HbS) fiber. Here we
have constructed two novel double mutants, HbS (K16Q/E23Q) and (H20Q/E23Q), with a view to delineate cumulative impact of
interactions emanating from the above contact sites. Far-UV and visible region CD spectra of the double mutants were similar
to the native HbS indicating the presence of native-like secondary and tertiary structure in the mutants. The quaternary structures
in both the mutants were also preserved as judged by the derivative UV spectra of liganded (oxy) and unliganded (deoxy) forms
of the double mutants. However, the double mutants displayed interesting polymerization behavior. The polymerization behaviour
of the double mutants was found to be non-additive of the individual single mutants. While HbS (H20Q/E23Q) showed inhibitory
effect similar to that of HbS (E23Q), the intrinsic inhibitory propensity of the associated single mutants was totally quelled
in HbS (K16Q/E23Q) double mutant. Molecular dynamics (MD) simulations studies of the isolated α-chains as well as a module
of the fiber containing the double and associated single mutants suggested that these contact sites at the axial interface
of the fiber impact HbS polymerization through a coupled interaction network. The overall results demonstrate a subtle role
of dynamics and electrostatics in the polymer formation and provide insights about interaction-linkage in HbS fiber assembly. 相似文献
45.
Arup Kr. Malakar Debashree Choudhury Binata Halder Prosenjit Paul Arif Uddin Supriyo Chakraborty 《Journal of cellular physiology》2019,234(10):16812-16823
Coronary artery disease (CAD) is one of the major cardiovascular diseases affecting the global human population. This disease has been proved to be the major cause of death in both the developed and developing countries. Lifestyle, environmental factors, and genetic factors pose as risk factors for the development of cardiovascular disease. The prevalence of risk factors among healthy individuals elucidates the probable occurrence of CAD in near future. Genome-wide association studies have suggested the association of chromosome 9p21.3 in the premature onset of CAD. The risk factors of CAD include diabetes mellitus, hypertension, smoking, hyperlipidemia, obesity, homocystinuria, and psychosocial stress. The eradication and management of CAD has been established through extensive studies and trials. Antiplatelet agents, nitrates, β-blockers, calcium antagonists, and ranolazine are some of the few therapeutic agents used for the relief of symptomatic angina associated with CAD. 相似文献
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48.
Sen P Mukherjee S Bhaumik G Das P Ganguly S Choudhury N Raha S 《Mutation research》2003,529(1-2):87-94
Exposure of Chinese hamster V79 fibroblasts to mild and repetitive H2O2 doses in culture for 15 weeks produced no change in lipid peroxidation status, GSH/GSSG ratio and glutathione peroxidase activity of these cells (VST cells). In contrast, in VST cells catalase levels underwent a prominent increase which could be significantly inhibited and brought down to control levels after treatment with the catalase inhibitor 3-aminotriazole (3-AT). When control (VC) cells were exposed to UV radiation (UVC 5 J/m2) or H2O2 (7.5mM, 15 min), intracellular reactive oxygen species (ROS) levels rose prominently with significant activation of caspase-3. Marked nuclear fragmentation and lower cell viability were also noted in these cells. In contrast, VST cells demonstrated a significantly lower ROS level, an absence of nuclear fragmentation and an unchanged caspase-3 activity after exposure to UVC or H2O2. Cell viability was also significantly better preserved in VST cells than VC cells after UV or H2O2 exposures. Following 3-AT treatment of VST cells, UVC radiation or H2O2 brought about significantly higher elevations in intracellular ROS, increases in caspase-3 activity, significantly lowered cell viability and marked nuclear fragmentation, indicating the involvement of high catalase levels in the cytoprotective effects of repetitive stress. Therefore, upregulation of the antioxidant defense after repetitive oxidative stress imparted a superior ability to cope with subsequent acute stress and escape apoptotic death and loss of viability. 相似文献
49.
Dasgupta J Sen U Choudhury D Datta P Chakrabarti A Chakrabarty SB Chakrabarty A Dattagupta JK 《Biochemical and biophysical research communications》2003,303(2):619-623
Hemoglobin A(2) (alpha(2)delta(2)), a minor (2-3%) component of circulating red blood cells, acts as an anti-sickling agent and its elevated concentration in beta-thalassemia is a useful clinical diagnostic. In beta-thalassemia major, where there is a failure of beta-chain production, HbA(2) acts as the predominant oxygen delivery mechanism. Hemoglobin E, is another common abnormal hemoglobin, caused by splice site mutation in exon 1 of beta globin gene, when combines with beta-thalassemia, causes severe microcytic anemia. The purification, crystallization, and preliminary structural studies of HbA(2) and HbE are reported here. HbA(2) and HbE are purified by cation exchange column chromatography in presence of KCN from the blood samples of individuals suffering from beta-thalassemia minor and E beta-thalassemia. X-ray diffraction data of HbA(2) and HbE were collected upto 2.1 and 1.73 A, respectively. HbA(2) crystallized in space group P2(1) with unit cell parameters a=54.33 A, b=83.73 A, c=62.87 A, and beta=99.80 degrees whereas HbE crystallized in space group P2(1)2(1)2(1) with unit cell parameters a=60.89 A, b=95.81 A, and c=99.08 A. Asymmetric unit in each case contains one Hb tetramer in R(2) state. 相似文献
50.