2,009 research outputs found

    Topological dynamical quantum phase transition in a quantum skyrmion phase

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    Quantum skyrmionic phase is modelled in a 2D helical spin lattice. This topological skyrmionic phase retains its nature in a large parameter space before moving to a ferromagnetic phase. Next nearest-neighbour interaction improves the stability and it also causes a shift of the topological phase in the parameter space. Nonanalytic behaviour of the rate function observed, when the system which is initially in a quantum skyrmion phase is quenched to a trivial quantum ferromagnetic phase, indicates a dynamical quantum phase transition. Dynamical quantum phase transition is absent when the system initially in a skyrmion phase is quenched to a helical phase

    COMPARATIVE DOCKING STUDIES ON THE EFFECT OF COMMERCIAL DRUGS ON DIPEPTIDYL PEPTIDASE-4 (DPP-4)

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    Objective: The aim of our study was to validate the accuracy of computational tools in drug discovery and molecular interaction studies by studying the inhibitory activity of various commercial drugs on DPP-4.Methods: In order to validate the accuracy of computational tools, 50 commercially available drugs were docked with DPP-4, a major target for type 2 diabetes treatment. Studies were performed using Discovery studio 3.5.Results: The analysis showed that out of the fifty selected drugs, 33 drugs passed the Lipinski's rule and commercially prescribed drugs namely Sulfonylurea, Pregabalin and Metaformin were found to have maximum interaction with the target.Conclusion: These major drugs which yielded the best results were found to be used in the treatment of diabetes which reconfirms the efficacy of these drugs, druggability of the target as well as the accuracy of the tool used

    Estimation of sea water salinity from dielectric measurements: Effect of temperature

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    Dielectric measurements have been carried out for distilled water and saline water solutions of salinities 10000, 20000, 30000, 40000 ppm, as well as sea water of Diu beach area, using Anritsu Shockline Vector Network Analyzer (VNA, model no: MS46322A) in the frequency range from 1 GHz to 20 GHz, over the temperatures of 20°, 30° and 40 °C. From the measured values of dielectric constant and dielectric loss, the values of tanδ, conductivity and emissivity of water solutions have been calculated. The variation in dielectric properties of water with salinity and temperature of measurement is compared with values calculated using Stogryn equations as well as Klein and Swift model and results are found to be in good agreement with corresponding values. From the dielectric loss values and the emissivity values of distilled water and saline water solutions at certain fixed frequencies, the salinity of sea water collected from Diu beach has been estimated to be 36,327 ppm which agrees very well with the physicochemical analysis report of laboratory

    Structural basis for CD1d presentation of a sulfatide derived from myelin and its implications for autoimmunity

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    Sulfatide derived from the myelin stimulates a distinct population of CD1d-restricted natural killer T (NKT) cells. Cis-tetracosenoyl sulfatide is one of the immunodominant species in myelin as identified by proliferation, cytokine secretion, and CD1d tetramer staining. The crystal structure of mouse CD1d in complex with cis-tetracosenoyl sulfatide at 1.9 Å resolution reveals that the longer cis-tetracosenoyl fatty acid chain fully occupies the A′ pocket of the CD1d binding groove, whereas the sphingosine chain fills up the F′ pocket. A precise hydrogen bond network in the center of the binding groove orients and positions the ceramide backbone for insertion of the lipid tails in their respective pockets. The 3′-sulfated galactose headgroup is highly exposed for presentation to the T cell receptor and projects up and away from the binding pocket due to its β linkage, compared with the more intimate binding of the α-glactosyl ceramide headgroup to CD1d. These structure and binding data on sulfatide presentation by CD1d have important implications for the design of therapeutics that target T cells reactive for myelin glycolipids in autoimmune diseases of the central nervous system

    Instruments of RT-2 Experiment onboard CORONAS-PHOTON and their test and evaluation III: Coded Aperture Mask and Fresnel Zone Plates in RT-2/CZT Payload

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    Imaging in hard X-rays of any astrophysical source with high angular resolution is a challenging job. Shadow-casting technique is one of the most viable options for imaging in hard X-rays. We have used two different types of shadow-casters, namely, Coded Aperture Mask (CAM) and Fresnel Zone Plate (FZP) pair and two types of pixellated solid-state detectors, namely, CZT and CMOS in RT-2/CZT payload, the hard X-ray imaging instrument onboard the CORONAS-PHOTON satellite. In this paper, we present the results of simulations with different combinations of coders (CAM & FZP) and detectors that are employed in the RT-2/CZT payload. We discuss the possibility of detecting transient Solar flares with good angular resolution for various combinations. Simulated results are compared with laboratory experiments to verify the consistency of the designed configuration.Comment: 27 pages, 16 figures, Accepted for publication in Experimental Astronomy (in press

    The co-occurrence of anemia and cardiometabolic disease risk demonstrates sex-specific sociodemographic patterning in an urbanizing rural region of southern India

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    BACKGROUND/OBJECTIVES: To determine the extent and sociodemographic determinants of anemia, overweight, metabolic syndrome (MetS), and the co-occurrence of anemia with cardiometabolic disease risk factors among a cohort of Indian adults. SUBJECT/METHODS: Cross-sectional survey of adult men (n=3,322) and non-pregnant women (n=2,895) aged 18 y and older from the third wave of the Andhra Pradesh Children and Parents Study that assessed anemia, overweight based on Body Mass Index, and prevalence of MetS based on abdominal obesity, hypertension, and blood lipid and fasting glucose measures. We examined associations of education, wealth and urbanicity with these outcomes and their co-occurrence. RESULTS: The prevalence of anemia and overweight was 40% and 29% among women, respectively, and 10% and 25% among men (P<0.001), respectively, while the prevalence of MetS was the same across sexes (15%) (P=0.55). The prevalence of concurrent anemia and overweight (9%), and anemia and MetS (4.5%) was highest among women. Household wealth was positively associated with overweight and MetS across sexes (P<0.05). Independent of household wealth, higher education was positively correlated with MetS among men (OR (95% CI): MetS: 1.4 (0.99, 2.0)) and negatively correlated with MetS among women (MetS: 0.54 (0.29, 0.99)). Similar sex-specific associations were observed for the co-occurrence of anemia with overweight and MetS. CONCLUSION: Women in this region of India may be particularly vulnerable to co-occurring anemia and cardiometabolic risk, and associated adverse health outcomes as the nutrition transition advances in India

    Physics Potential of the ICAL detector at the India-based Neutrino Observatory (INO)

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    The upcoming 50 kt magnetized iron calorimeter (ICAL) detector at the India-based Neutrino Observatory (INO) is designed to study the atmospheric neutrinos and antineutrinos separately over a wide range of energies and path lengths. The primary focus of this experiment is to explore the Earth matter effects by observing the energy and zenith angle dependence of the atmospheric neutrinos in the multi-GeV range. This study will be crucial to address some of the outstanding issues in neutrino oscillation physics, including the fundamental issue of neutrino mass hierarchy. In this document, we present the physics potential of the detector as obtained from realistic detector simulations. We describe the simulation framework, the neutrino interactions in the detector, and the expected response of the detector to particles traversing it. The ICAL detector can determine the energy and direction of the muons to a high precision, and in addition, its sensitivity to multi-GeV hadrons increases its physics reach substantially. Its charge identification capability, and hence its ability to distinguish neutrinos from antineutrinos, makes it an efficient detector for determining the neutrino mass hierarchy. In this report, we outline the analyses carried out for the determination of neutrino mass hierarchy and precision measurements of atmospheric neutrino mixing parameters at ICAL, and give the expected physics reach of the detector with 10 years of runtime. We also explore the potential of ICAL for probing new physics scenarios like CPT violation and the presence of magnetic monopoles.Comment: 139 pages, Physics White Paper of the ICAL (INO) Collaboration, Contents identical with the version published in Pramana - J. Physic

    The Sirt1 activator SRT3025 provides atheroprotection in Apoe−/− mice by reducing hepatic Pcsk9 secretion and enhancing Ldlr expression

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    Aims The deacetylase sirtuin 1 (Sirt1) exerts beneficial effects on lipid metabolism, but its roles in plasma LDL-cholesterol regulation and atherosclerosis are controversial. Thus, we applied the pharmacological Sirt1 activator SRT3025 in a mouse model of atherosclerosis and in hepatocyte culture. Methods and results Apolipoprotein E-deficient (Apoe−/−) mice were fed a high-cholesterol diet (1.25% w/w) supplemented with SRT3025 (3.18 g kg−1 diet) for 12 weeks. In vitro, the drug activated wild-type Sirt1 protein, but not the activation-resistant Sirt1 mutant; in vivo, it increased deacetylation of hepatic p65 and skeletal muscle Foxo1. SRT3025 treatment decreased plasma levels of LDL-cholesterol and total cholesterol and reduced atherosclerosis. Drug treatment did not change mRNA expression of hepatic LDL receptor (Ldlr) and proprotein convertase subtilisin/kexin type 9 (Pcsk9), but increased their protein expression indicating post-translational effects. Consistent with hepatocyte Ldlr and Pcsk9 accumulation, we found reduced plasma levels of Pcsk9 after pharmacological Sirt1 activation. In vitro administration of SRT3025 to cultured AML12 hepatocytes attenuated Pcsk9 secretion and its binding to Ldlr, thereby reducing Pcsk9-mediated Ldlr degradation and increasing Ldlr expression and LDL uptake. Co-administration of exogenous Pcsk9 with SRT3025 blunted these effects. Sirt1 activation with SRT3025 in Ldlr−/− mice reduced neither plasma Pcsk9, nor LDL-cholesterol levels, nor atherosclerosis. Conclusion We identify reduction in Pcsk9 secretion as a novel effect of Sirt1 activity and uncover Ldlr as a prerequisite for Sirt1-mediated atheroprotection in mice. Pharmacological activation of Sirt1 appears promising to be tested in patients for its effects on plasma Pcsk9, LDL-cholesterol, and atherosclerosi
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