2,748 research outputs found
The Hydrodynamical Limit of Quantum Hall system
We study the current algebra of FQHE systems in the hydrodynamical limit of
small amplitude, long-wavelength fluctuations. We show that the algebra
simplifies considerably in this limit. The hamiltonian is expressed in a
current-current form and the operators creating inter-Landau level and lowest
Landau level collective excitations are identified.Comment: Revtex, 16 page
Binding of SARS-CoV Covalent Non-Covalent Inhibitors to the SARS-CoV-2 Papain-Like Protease and Ovarian Tumor Domain Deubiquitinases
The urgent need for novel and effective drugs against the SARS-CoV-2 coronavirus pandemic has stimulated research worldwide. The Papain-like protease (PLpro), which is essential for viral replication, shares a similar active site structural architecture to other cysteine proteases. Here, we have used representatives of the Ovarian Tumor Domain deubiquitinase family OTUB1 and OTUB2 along with the PLpro of SARS-CoV-2 to validate and rationalize the binding of inhibitors from previous SARS-CoV candidate compounds. By forming a new chemical bond with the cysteine residue of the catalytic triad, covalent inhibitors irreversibly suppress the protein’s activity. Modeling covalent inhibitor binding requires detailed knowledge about the compounds’ reactivities and binding. Molecular Dynamics refinement simulations of top poses reveal detailed ligand-protein interactions and show their stability over time. The recently discovered selective OTUB2 covalent inhibitors were used to establish and validate the computational protocol. Structural parameters and ligand dynamics are in excellent agreement with the ligand-bound OTUB2 crystal structures. For SARS-CoV-2 PLpro, recent covalent peptidomimetic inhibitors were simulated and reveal that the ligand-protein interaction is very dynamic. The covalent and non-covalent docking plus subsequent MD refinement of known SARS-CoV inhibitors into DUBs and the SARS-CoV-2 PLpro point out a possible approach to target the PLpro cysteine protease from SARS-CoV-2. The results show that such an approach gives insight into ligand-protein interactions, their dynamic character, and indicates a path for selective ligand design
MOLECULAR DOCKING STUDIES ON THIADIAZOLE DERIVATIVES AS PROTEIN KINASE INHIBITORS
Objective: In the present study, a novel series of 1, 3, 4-thiadiazole derivatives were docked against the mycobacterium tuberculosis protein kinase G. 1, 3, 4–thiadiazole derivatives with a modified primary amine group at 5th position were used for docking studies.
Methods: The three-dimensional structure of the protein was obtained from PDB, and its active sites were predicted. The structures of all the compounds were drawn using chemdraw software version 8.0. The docking studies were done by using schrödinger software against the enzyme protein kinase G. Totally eighteen compounds was synthesized based on glide score
Results: In this Docking study the thiadiazole analogues were showing good binding energy. The amino acids residues GLU588, SER412, GLY410 and GLU 628 in the kinase domain active site form hydrogen bonds with the ligand.
Conclusion: The compounds D34, D16, D7, D25, D15, and D27 showed better interaction with protein kinase G (pknG) more than the other drug molecule
EFFECTS OF HOME EXERCISE PROGRAMME ON SHOULDER PAIN AND FUNCTIONAL STATUS IN MALE CONSTRUCTION WORKERS
Objective: To evaluate the effect of home exercise program on shoulder pain and functional status in male construction workers.Methods: Study design was quasi-experimental study, subjects were 30 male construction workers, n=15 Group A (experimental) and n=15 Group B (control). Subjects in the experimental group were instructed in a 6 weeks home exercise program, Group B subjects were treated with only ergonomic advices. The outcome measurements were visual analog scale and shoulder pain and disability index.Results: The results of this study showed that significant reduction in pain and improvement in the functional status of construction workers in Group A than Group B.Conclusion: The study concluded that there was a significant reduction in shoulder pain and improvement in functional status by home exercise program than ergonomic advices in male construction workers
Income Inequality and Consumption Pattern Among BOP Consumers in India
Marketing discipline has evolved through the context of the industrialized or developed world. However, the largest groups of consumers are also the poorest (Bottom of the Pyramid category) and economic inequality is still persisting among BOP consumers. Using the Gini co-efficient, economic inequality was measured with the help of World Bank report. The main aim of this paper is to know about the trends that took place in income inequality and consumption pattern among BOP consumers based on household surveys (from NSSO and World Bank). It shows that income inequality among BOP consumers has been increasing simultaneously with increase in consumption pattern among BOP consumers because income growth would leads to truly middle-class led one with growing of consumer spending from 6 trillion by 2030. Further, income growth lifts 25 million households from poverty and in 2030 among that fewer than 5 per cent of households will be in below poverty
Efficient Database Distribution Using Local Search Algorithm
A problem in railway database is identied. Focus of the problem is to reduce the average response
time for all the read and write queries to the railway database. One way of doing this is by opening
more than one database servers and distributing the database across these servers to improve the
performance. In this work we are proposing an ecient distribution of the database across these
servers considering read and write request frequencies at all locations.
The problem of database distribution across dierent locations is mapped to the well studied
problem called Uncapacitated Facility Location(UFL) problem. Various techniques such as greedy
approach, LP rounding technique, primal-dual technique and local search have been proposed to
tackle this problem. Of those, we are using local search technique in this work. In particular, poly-
nomial version of the local search approximation algorithm is used to solve the railway database
problem. Distributed database is implemented using postgresql database server and jboss appli-
cation server is used to manage the global transaction. On this architecture, database is distributed
using the local optimal solution obtained by local search algorithm and it is compared with other
solutions in terms of the average response time for the read and write requests
Human Cytomegalovirus glycoprotein UL16 causes intracellular sequestration of NKG2D ligands, protecting against NK cell cytotoxicity.
The activating receptor, NKG2D, is expressed on a variety of immune effector cells and recognizes divergent families of major histocompatibility complex (MHC) class I-related ligands, including the MIC and ULBP proteins. Infection, stress, or transformation can induce NKG2D ligand expression, resulting in effector cell activation and killing of the ligand-expressing target cell. The human cytomegalovirus (HCMV) membrane glycoprotein, UL16, binds to three of the five known ligands for human NKG2D. UL16 is retained in the endoplasmic reticulum and cis-Golgi apparatus of cells and causes MICB to be similarly retained and stabilized within cells. Coexpression of UL16 markedly reduces cell surface levels of MICB, ULBP1, and ULBP2, and decreases susceptibility to natural killer cell-mediated cytotoxicity. Domain swapping experiments demonstrate that the transmembrane and cytoplasmic domains of UL16 are important for intracellular retention of UL16, whereas the ectodomain of UL16 participates in down-regulation of NKG2D ligands. The intracellular sequestration of NKG2D ligands by UL16 represents a novel HCMV immune evasion mechanism to add to the well-documented viral strategies directed against antigen presentation by classical MHC molecules
Laves Phase in Alloy 718 Fusion Zone
The gas tungsten arc (GTA) welded fusion zone of alloy 718 has been well investigated on the formation of interdendritic Laves phase. This article deals with the various process control methodologies for minimizing the microsegregation and Laves phase such as the enhanced weld cooling rate in GTA welding (GTAW) process and modification in weld metal chemistry. Even though the high energy density welding processes such as electron beam (EB) and laser beam (LB) welding techniques are proven in minimizing the microsegregation and Laves phase, the requirement of conventional GTA welding process still exists in the aerospace industry due to the complex shapes of the components and the inaccessible conditions for executing the welding process. The enhancement in the weld cooling rate and modified weld metal chemistry resulted in the refined fusion zone microstructure and reduced microsegregation. Enhanced weld efficiency on ultimate tensile strength (UTS) and 0.2% YS at 25°C was observed to the tune of 85 to 93% by employing cryogenic cooling in GTA welding process. Similar improvement in weld efficiency at 650°C was observed. However, the evaluated weld efficiencies with cryogenically cooled weld metal were marginally lower than the previous works in EB and LB welds only by 2–3%
Strain rate effect on the mechanical behaviour of a textile reinforced cement composite
The static tensile behaviour of Textile Reinforced Cement Composites is known and can be modeled adequately. However, using these static material properties under dynamic loadings such as impact and seismic loadings, can cause over- or underestimation of the material due to effects of strain rate. This work focuses on the strain rate dependency of a specific textile reinforced cement composite under tensile loadings at strain rates equivalent to quasi static applications towards low velocity impacts. It was found that the main damage mechanisms of this material stay the same. However cracking of the cement matrix is delayed to higher stress levels
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