889 research outputs found

    Strength and Durability of Hybrid Fibre Reinforced Binary Blend Geopolymer Concrete

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    This paper deals with an investigation on the influence of hybrid fibres on the strength and durability of binary blend geopolymer concrete. Geopolymer concrete was prepared using Fly ash and GGBS as source material and mix design was carried out as per the guidelines of Professor Rangan of Curtin University, Australia. Different fly ash-GGBS proportions namely 50-50%, 60-40%, 70-30%, 80-20% and 90-10% were considered. The tests on Geopolymer concrete reveal that the compressive strength increases as the percentage of GGBS increases up to 30%. Hence the combination of 70% fly ash and 30% GGBS was considered as a base material. In order to improve the engineering properties of the Geopolymer concrete, hybrid fibres which consist of metallic and non-metallic fibres were introduced in the base material. Metallic fibres considered was crimped steel fibres with different percentages of volume fraction viz. 0.5% and 1.0% and non-metallic fibres considered was basalt fibres with different percentages of volume fraction viz. 0.1%, 0.2% and 0.3%. Strength parameters such as compressive strength, split tensile strength, modulus of rupture and modulus of elasticity were obtained for various combinations of steel and basalt fibres. Similarly durability parameters which include permeability, water absorption, marine attack and sulphuric acid attack were also evaluated. The combination of fibres having 0.5% steel and 0.3% basalt gave better results with regard to both strength and durability of binary blend Geopolymer concrete

    INSILICO DOCKING STUDIES TO IDENTIFY POTENT INHIBITORS OF ALPHA-SYNUCLEIN AGGREGATION IN PARKINSON DISEASE

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    Background: Parkinson's disease (PD) is the second most common neurodegenerative disorder after Alzheimer's disease. Etiology of PD is progressive loss of dopaminergic neurons in Substantia nigra pars compacta (SNpc). One of the pathological hallmarks of PD is the presence of intracellular proteinaceous substances termed ‘Lewy bodies' composed of aggregated alpha-synuclein which is responsible for its toxic effect on SNpc. Hence any therapeutic target which blocks α-synuclein aggregation will provide a new channel to cure PD. Objective: The aim of the present study is to identify potent inhibitors (ligands) which binds to active site of α-synuclein and prevents self-association. Methods: In this study, insilico molecular docking was done against α-synuclein using five plant derived compounds namely (a) stimovul (b) 7,8dihydroxycoumarin, (c) etorphine (d) propoxyphene and (e) pentazdine. These compounds were analyzed for their Lipinski and ADMET properties using Accelrys Discovery studio 3.5. Molecular docking was performed between ligand and protein using Lead IT. Results: Results revealed that the best fit ligands against active site of α-synuclein were identified as Stimovul with a docking score of -4.5122 and the interacting amino acids were found to be SER 87 and VAL 95 followed by other compounds. Conclusion: These compounds which have the ability to bind to α-Synuclein insilico can be further developed using invitro and in vivo studies as a potent anti-parkinson drug.   Keywords: Parkinson disease, Substantia nigra, Molecular docking, Lipinski, ADMET

    Cancer cells adapt FAM134B/BiP mediated ER-phagy to survive hypoxic stress

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    In the tumor microenvironment, cancer cells experience hypoxia resulting in the accumulation of misfolded/unfolded proteins largely in the endoplasmic reticulum (ER). Consequently, ER proteotoxicity elicits unfolded protein response (UPR) as an adaptive mechanism to resolve ER stress. In addition to canonical UPR, proteotoxicity also stimulates the selective, autophagy-dependent, removal of discrete ER domains loaded with misfolded proteins to further alleviate ER stress. These mechanisms can favor cancer cell growth, metastasis, and long-term survival. Our investigations reveal that during hypoxia-induced ER stress, the ER-phagy receptor FAM134B targets damaged portions of ER into autophagosomes to restore ER homeostasis in cancer cells. Loss of FAM134B in breast cancer cells results in increased ER stress and reduced cell proliferation. Mechanistically, upon sensing hypoxia-induced proteotoxic stress, the ER chaperone BiP forms a complex with FAM134B and promotes ER-phagy. To prove the translational implication of our mechanistic findings, we identified vitexin as a pharmacological agent that disrupts FAM134B-BiP complex, inhibits ER-phagy, and potently suppresses breast cancer progression in vivo

    Profiling the differentially expressed genes in two rice varieties during rapid grain-filling stages

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    Grain filling is an important agronomic trait, which directly affects the final yield of rice. Partially filled and empty rice grains are among the factors that limit the yield of MR219, one of the highest yielding rice varieties in Malaysia. In this study, the NSF 20 K rice oligonucleotide array, which contains 20,000 70-mer oligonucleotide probes, was used for direct comparison of the transcriptomes of MR219 and MR84 (a rice variety that has higher percentage of filled grains compared to MR219), during rapid grain-filling period at 5 and 10 days after fertilization (DAF). A total of 155 and 233 genes were differentially expressed in MR219 compared to MR84 at 5 and 10 DAF, respectively; and 9 of these expression ratios were tested using quantitative real-time RT PCR. Among the differentially expressed genes identified were those encoding hexokinase, various sugar transporters, GSDL-like lipase/acylhydrolase, brassinosteroid-insensitive 1-associated receptor kinase 1 precursor and homeobox protein GLABRA2, which were analyzed by real-time RT PCR in this study. The differences demonstrated by these genes in their transcript levels and profiles, between the two rice varieties understudied at different stages of grain filling may contribute to the formulation of hypotheses toward the understanding of poor percentage of filled grains in MR219

    Predictive modeling for perinatal mortality in resource-limited settings

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    Importance: The overwhelming majority of fetal and neonatal deaths occur in low- and middle-income countries. Fetal and neonatal risk assessment tools may be useful to predict the risk of death.Objective: To develop risk prediction models for intrapartum stillbirth and neonatal death.Design, setting, and participants: This cohort study used data from the Eunice Kennedy Shriver National Institute of Child Health and Human Development Global Network for Women\u27s and Children\u27s Health Research population-based vital registry, including clinical sites in South Asia (India and Pakistan), Africa (Democratic Republic of Congo, Zambia, and Kenya), and Latin America (Guatemala). A total of 502 648 pregnancies were prospectively enrolled in the registry.Exposures: Risk factors were added sequentially into the data set in 4 scenarios: (1) prenatal, (2) predelivery, (3) delivery and day 1, and (4) postdelivery through day 2.Main outcomes and measures: Data sets were randomly divided into 10 groups of 3 analysis data sets including training (60%), test (20%), and validation (20%). Conventional and advanced machine learning modeling techniques were applied to assess predictive abilities using area under the curve (AUC) for intrapartum stillbirth and neonatal mortality.Results: All prenatal and predelivery models had predictive accuracy for both intrapartum stillbirth and neonatal mortality with AUC values 0.71 or less. Five of 6 models for neonatal mortality based on delivery/day 1 and postdelivery/day 2 had increased predictive accuracy with AUC values greater than 0.80. Birth weight was the most important predictor for neonatal death in both postdelivery scenarios with independent predictive ability with AUC values of 0.78 and 0.76, respectively. The addition of 4 other top predictors increased AUC to 0.83 and 0.87 for the postdelivery scenarios, respectively.Conclusions and relevance: Models based on prenatal or predelivery data had predictive accuracy for intrapartum stillbirths and neonatal mortality of AUC values 0.71 or less. Models that incorporated delivery data had good predictive accuracy for risk of neonatal mortality. Birth weight was the most important predictor for neonatal mortality

    Measurement of χ c1 and χ c2 production with s√ = 7 TeV pp collisions at ATLAS

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    The prompt and non-prompt production cross-sections for the χ c1 and χ c2 charmonium states are measured in pp collisions at s√ = 7 TeV with the ATLAS detector at the LHC using 4.5 fb−1 of integrated luminosity. The χ c states are reconstructed through the radiative decay χ c → J/ψγ (with J/ψ → μ + μ −) where photons are reconstructed from γ → e + e − conversions. The production rate of the χ c2 state relative to the χ c1 state is measured for prompt and non-prompt χ c as a function of J/ψ transverse momentum. The prompt χ c cross-sections are combined with existing measurements of prompt J/ψ production to derive the fraction of prompt J/ψ produced in feed-down from χ c decays. The fractions of χ c1 and χ c2 produced in b-hadron decays are also measured

    Measurement of the production of a W boson in association with a charm quark in pp collisions at √s = 7 TeV with the ATLAS detector

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    The production of a W boson in association with a single charm quark is studied using 4.6 fb−1 of pp collision data at s√ = 7 TeV collected with the ATLAS detector at the Large Hadron Collider. In events in which a W boson decays to an electron or muon, the charm quark is tagged either by its semileptonic decay to a muon or by the presence of a charmed meson. The integrated and differential cross sections as a function of the pseudorapidity of the lepton from the W-boson decay are measured. Results are compared to the predictions of next-to-leading-order QCD calculations obtained from various parton distribution function parameterisations. The ratio of the strange-to-down sea-quark distributions is determined to be 0.96+0.26−0.30 at Q 2 = 1.9 GeV2, which supports the hypothesis of an SU(3)-symmetric composition of the light-quark sea. Additionally, the cross-section ratio σ(W + +c¯¯)/σ(W − + c) is compared to the predictions obtained using parton distribution function parameterisations with different assumptions about the s−s¯¯¯ quark asymmetry

    Measurements of fiducial and differential cross sections for Higgs boson production in the diphoton decay channel at s√=8 TeV with ATLAS

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    Measurements of fiducial and differential cross sections are presented for Higgs boson production in proton-proton collisions at a centre-of-mass energy of s√=8 TeV. The analysis is performed in the H → γγ decay channel using 20.3 fb−1 of data recorded by the ATLAS experiment at the CERN Large Hadron Collider. The signal is extracted using a fit to the diphoton invariant mass spectrum assuming that the width of the resonance is much smaller than the experimental resolution. The signal yields are corrected for the effects of detector inefficiency and resolution. The pp → H → γγ fiducial cross section is measured to be 43.2 ±9.4(stat.) − 2.9 + 3.2 (syst.) ±1.2(lumi)fb for a Higgs boson of mass 125.4GeV decaying to two isolated photons that have transverse momentum greater than 35% and 25% of the diphoton invariant mass and each with absolute pseudorapidity less than 2.37. Four additional fiducial cross sections and two cross-section limits are presented in phase space regions that test the theoretical modelling of different Higgs boson production mechanisms, or are sensitive to physics beyond the Standard Model. Differential cross sections are also presented, as a function of variables related to the diphoton kinematics and the jet activity produced in the Higgs boson events. The observed spectra are statistically limited but broadly in line with the theoretical expectations

    Search for squarks and gluinos with the ATLAS detector in final states with jets and missing transverse momentum using √s=8 TeV proton-proton collision data

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    A search for squarks and gluinos in final states containing high-p T jets, missing transverse momentum and no electrons or muons is presented. The data were recorded in 2012 by the ATLAS experiment in s√=8 TeV proton-proton collisions at the Large Hadron Collider, with a total integrated luminosity of 20.3 fb−1. Results are interpreted in a variety of simplified and specific supersymmetry-breaking models assuming that R-parity is conserved and that the lightest neutralino is the lightest supersymmetric particle. An exclusion limit at the 95% confidence level on the mass of the gluino is set at 1330 GeV for a simplified model incorporating only a gluino and the lightest neutralino. For a simplified model involving the strong production of first- and second-generation squarks, squark masses below 850 GeV (440 GeV) are excluded for a massless lightest neutralino, assuming mass degenerate (single light-flavour) squarks. In mSUGRA/CMSSM models with tan β = 30, A 0 = −2m 0 and μ > 0, squarks and gluinos of equal mass are excluded for masses below 1700 GeV. Additional limits are set for non-universal Higgs mass models with gaugino mediation and for simplified models involving the pair production of gluinos, each decaying to a top squark and a top quark, with the top squark decaying to a charm quark and a neutralino. These limits extend the region of supersymmetric parameter space excluded by previous searches with the ATLAS detector

    Search for squarks and gluinos in events with isolated leptons, jets and missing transverse momentum at s√=8 TeV with the ATLAS detector

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    The results of a search for supersymmetry in final states containing at least one isolated lepton (electron or muon), jets and large missing transverse momentum with the ATLAS detector at the Large Hadron Collider are reported. The search is based on proton-proton collision data at a centre-of-mass energy s√=8 TeV collected in 2012, corresponding to an integrated luminosity of 20 fb−1. No significant excess above the Standard Model expectation is observed. Limits are set on supersymmetric particle masses for various supersymmetric models. Depending on the model, the search excludes gluino masses up to 1.32 TeV and squark masses up to 840 GeV. Limits are also set on the parameters of a minimal universal extra dimension model, excluding a compactification radius of 1/R c = 950 GeV for a cut-off scale times radius (ΛR c) of approximately 30
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