Amit Singh

Bio: Amit Singh is an academic researcher from National Institute of Technology, Patna. The author has contributed to research in topics: Digital watermarking & Watermark. The author has an hindex of 57, co-authored 640 publications receiving 13795 citations. Previous affiliations of Amit Singh include Ithaca College & Center for Infectious Disease Research and Policy.

Discovery of Histone Deacetylase Inhibitor Using Molecular Modeling and Free Energy Calculations

Abstract: The histone acetylation–deacetylation at lysine regulates the functions of many cellular proteins. An increased expression of HDAC6 can cause an increased amount of deacetylated histones, which leads to an inhibition of gene expression and has been associated with cancer cell proliferation. The present study screened the ZINC database to find novel HDAC6 inhibitors using virtual high-throughput screening techniques. The docking score, free energy, and binding pattern of the complexes were used to select a best ligand for further study. Molecular dynamic simulations, binding interactions, and the stability of docked conformations were investigated. Several parameters that determine protein–ligand interactions, such as root-mean-square deviation (RMSD), root-mean-square fluctuation (RMSF), radius of gyration (Rg), and binding pattern, were observed. Hydrogen bonds were observed at His 573 and Gly 582 after a 150 ns simulation with identified compound ZINC000002845205, and they were similar to known inhibitor Panobinostat. The molecular mechanics with generalised Born and surface area solvation (MM/GBSA) free energy was comparable to known inhibitor Panobinostat. ZINC000002845205 qualifies drug-likeness according to Lipinski’s rule-of-five, rule-of-three, and the World Drug Index (WDI)-like rule, but there is one violation in the lead-like rule.

Yield and Economics of Okra Seed Production Influenced by Growth Regulators and Micronutrients

Abstract: Okra or Bhindi (Abelmoschus esculentus (L.) Moench) commonly known as lady’s finger, belong to the family Malvaceae. It is one of the important summer vegetable grown widely in sub-tropical region of the world for its tender pods. Okra is one of the most important vegetable crops grown extensively thought the country during summer and rainy seasons due to high adaptability over a wide range of environmental conditions. It is one of the economically important vegetable crops grown in India. As a vegetable in tender stage, okra is nutritious and it finds an important place in the Indian dietary. Besides the utility of its tender green fingers as vegetables, it is used in soups and curries. Green pods are rich source of Iodine, vitamin A, B and C. The stems and roots of okra can also be used in paper industry.

Mevo lectin specificity toward high-mannose structures with terminal αMan(1,2)αMan residues and its implication to inhibition of the entry of Mycobacterium tuberculosis into macrophages

Abstract: Mannose-binding lectins can specifically recognize and bind complex glycan structures on pathogens and have potential as antiviral and antibacterial agents We previously reported the structure of a lectin from an archaeal species, Mevo lectin, which has specificity toward terminal α1,2 linked manno-oligosaccharides Mycobacterium tuberculosis expresses mannosylated structures including lipoarabinomannan (ManLAM) on its surface and exploits C-type lectins to gain entry into the host cells ManLAM structure has mannose capping with terminal αMan(1,2)αMan residues and is important for recognition by innate immune cells Here, we aim to address the specificity of Mevo lectin toward high-mannose type glycans with terminal αMan(1,2)αMan residues and its effect on M tuberculosis internalization by macrophages Isothermal titration calorimetry studies demonstrated that Mevo lectin shows preferential binding toward manno-oligosaccharides with terminal αMan(1,2)αMan structures and showed a strong affinity for ManLAM, whereas it binds weakly to Mycobacterium smegmatis lipoarabinomannan, which displays relatively fewer and shorter mannosyl caps Crystal structure of Mevo lectin complexed with a Man7D1 revealed the multivalent cross-linking interaction, which explains avidity-based high-affinity for these ligands when compared to previously studied manno-oligosaccharides lacking the specific termini Functional studies suggest that M tuberculosis internalization by the macrophage was impaired by binding of Mevo lectin to ManLAM present on the surface of M tuberculosis Selectivity shown by Mevo lectin toward glycans with terminal αMan(1,2)αMan structures, and its ability to compromise the internalization of M tuberculosis in vitro, underscore the potential utility of Mevo lectin as a research tool to study host-pathogen interactions

Green synthesis, Characterization and In vitro Biological Studies of Quercetin complexes with Zn (II) Acetate and N^N Moiety

Abstract: Green synthesis of two coordination complexes of zinc acetate with N^N moiety on quercetin, which is a flavonoid is carried out. The complexes were obtained in high yields (> 97%) by grinding methods without the involvement of any solvent. Neither catalyst nor any additives were needed to perform the reactions. It was characterized by FT-IR, UV-Vis, NMR, HRMS, and elemental analysis. Antioxidant activity was done through the DPPH method which was compared with ascorbic acid and ligand (Quercetin). The study reveals that Complex 1 (IC50 163.093µg/ml) has significant free radical scavenging activity as compared to complex 2 (IC50 258.683µg/ml). Biological activity was performed against microbes (E. coli and S. aureus). MIC value of complex 1 (15.50µg/ml E. coli, 7.18µg/ml S. aureus) was found more significant as compared to complex 2 (22.51µg/ml E. coli, 18.62µg/ml S. aureus) and quercetin.

Opposing roles for sMAdCAM and IL‐15 in COVID‐19 associated cellular immune pathology

Abstract: Immune cell dysregulation and lymphopenia characterize COVID‐19 pathology in moderate to severe disease. While underlying inflammatory factors have been extensively studied, homeostatic and mucosal migratory signatures remain largely unexplored as causative factors. In this study, we evaluated the association of circulating IL‐6, soluble mucosal addressin cell adhesion molecule (sMAdCAM), and IL‐15 with cellular dysfunction characterizing mild and hypoxemic stages of COVID‐19. A cohort of SARS‐CoV‐2 infected individuals (n = 130) at various stages of disease progression together with healthy controls (n = 16) were recruited from COVID Care Centres (CCCs) across Mumbai, India. Multiparametric flow cytometry was used to perform in‐depth immune subset characterization and to measure plasma IL‐6 levels. sMAdCAM, IL‐15 levels were quantified using ELISA. Distinct depletion profiles, with relative sparing of CD8 effector memory and CD4+ regulatory T cells, were observed in hypoxemic disease within the lymphocyte compartment. An apparent increase in the frequency of intermediate monocytes characterized both mild as well as hypoxemic disease. IL‐6 levels inversely correlated with those of sMAdCAM and both markers showed converse associations with observed lympho‐depletion suggesting opposing roles in pathogenesis. Interestingly, IL‐15, a key cytokine involved in lymphocyte activation and homeostasis, was detected in symptomatic individuals but not in healthy controls or asymptomatic cases. Further, plasma IL‐15 levels negatively correlated with T, B, and NK count suggesting a compensatory production of this cytokine in response to the profound lymphopenia. Finally, higher levels of plasma IL‐15 and IL‐6, but not sMAdCAM, were associated with a longer duration of hospitalization.

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

Pattern Recognition and Machine Learning

Abstract: Probability Distributions.- Linear Models for Regression.- Linear Models for Classification.- Neural Networks.- Kernel Methods.- Sparse Kernel Machines.- Graphical Models.- Mixture Models and EM.- Approximate Inference.- Sampling Methods.- Continuous Latent Variables.- Sequential Data.- Combining Models.

Harrison's Principles of Internal Medicine

Abstract: The 11th edition of Harrison's Principles of Internal Medicine welcomes Anthony Fauci to its editorial staff, in addition to more than 85 new contributors. While the organization of the book is similar to previous editions, major emphasis has been placed on disorders that affect multiple organ systems. Important advances in genetics, immunology, and oncology are emphasized. Many chapters of the book have been rewritten and describe major advances in internal medicine. Subjects that received only a paragraph or two of attention in previous editions are now covered in entire chapters. Among the chapters that have been extensively revised are the chapters on infections in the compromised host, on skin rashes in infections, on many of the viral infections, including cytomegalovirus and Epstein-Barr virus, on sexually transmitted diseases, on diabetes mellitus, on disorders of bone and mineral metabolism, and on lymphadenopathy and splenomegaly. The major revisions in these chapters and many

Shape‐Controlled Synthesis of Metal Nanocrystals: Simple Chemistry Meets Complex Physics?

Abstract: Nanocrystals are fundamental to modern science and technology. Mastery over the shape of a nanocrystal enables control of its properties and enhancement of its usefulness for a given application. Our aim is to present a comprehensive review of current research activities that center on the shape-controlled synthesis of metal nanocrystals. We begin with a brief introduction to nucleation and growth within the context of metal nanocrystal synthesis, followed by a discussion of the possible shapes that a metal nanocrystal might take under different conditions. We then focus on a variety of experimental parameters that have been explored to manipulate the nucleation and growth of metal nanocrystals in solution-phase syntheses in an effort to generate specific shapes. We then elaborate on these approaches by selecting examples in which there is already reasonable understanding for the observed shape control or at least the protocols have proven to be reproducible and controllable. Finally, we highlight a number of applications that have been enabled and/or enhanced by the shape-controlled synthesis of metal nanocrystals. We conclude this article with personal perspectives on the directions toward which future research in this field might take.