503 research outputs found

    IN-SITU RAMAN-SPECTROSCOPIC STUDY OF OXYGEN ADSPECIES ON A TH-LA-O-X CATALYST FOR METHANE OXIDATIVE COUPLING REACTION

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    The superoxide adspecies O-2(-) is identified by in situ Raman spectroscopy on a functioning Th-La-O-x catalyst for methane oxidative coupling reaction at 680-860 degrees C

    The Role of the p38 MAPK Signaling Pathway in High Glucose-Induced Epithelial-Mesenchymal Transition of Cultured Human Renal Tubular Epithelial Cells

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    Epithelial-mesenchymal transition of tubular epithelial cells, which is characterized by a loss of epithelial cell characteristics and a gain of ECM-producing myofibroblast characteristics, is an essential mechanism that is involved in tubulointerstitial fibrosis, an important component of the renal injury that is associated with diabetic nephropathy. Under diabetic conditions, p38 MAPK activation has been reported in glomeruli and mesangial cells; however, studies on p38 MAPK in TECs are lacking. In this study, the role of p38 MAPK in AP-1 activation and in the EMT in the human proximal tubular epithelial cell line (HK-2) under high glucose concentration conditions is investigated.A vector for small interfering RNA that targets p38 MAPK was constructed; the cells were then either transfected with p38 siRNA or pretreated with a chemical inhibitor of AP-1 and incubated with low glucose plus TGF-β1 or high glucose for 48 h. Cells that were not transfected or pretreated and were exposed to low glucose with or without TGF-β1 or high glucose for 48 h were considered to be the controls. We found that high glucose induced an increase in TGF-β1. And high glucose-induced p38 MAPK activation was inhibited by p38 siRNA (P<0.05). A significant decline in E-cadherin and CK expression and a notable increase in vimentin and α-SMA were detected when exposed to low glucose with TGF-β1 or high glucose, and a significant raise of secreted fibronectin were detected when exposed to high glucose; whereas these changes were reversed when the cells were treated with p38 siRNA or AP-1 inhibitor (P<0.05). AP-1 activity levels and Snail expression were up-regulated under high glucose conditions but were markedly down-regulated through knockdown of p38 MAPK with p38 siRNA or pretreatment with AP-1 inhibitor (P<0.05).This study suggests that p38 MAPK may play an important role in the high glucose-induced EMT by activating AP-1 in tubular epithelial cells

    MUC2 polymorphisms are associated with endometriosis development and infertility: a case-control study

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    <p>Abstract</p> <p>Background</p> <p>Mucins are highly glycosylated proteins protecting and lubricating epithelial surface of respiratory, gastrointestinal and reproductive tracts. Members of the mucin protein family have been suggested to play an important role in development of endometriosis and infertility. This study investigates genetic association of mucin2 (<it>MUC2</it>) with the risk of endometriosis and endometriosis-related infertility.</p> <p>Methods</p> <p>This case-control study was conducted at China Medical University Hospital, with 195 endometriosis patients and 196 healthy controls enrolled. Genotyping of six SNPs (rs2856111, rs11245936, rs10794288, rs10902088, rs7103978 and rs11245954) within <it>MUC2 </it>gene were performed by using <it>Taqman </it>genotyping assay; individual SNP and haplotype associations with endometriosis and endometriosis-related infertility were assessed by <it>χ</it><sup>2 </sup>test.</p> <p>Results</p> <p>Endometriosis patients exhibit significantly lower frequency of the rs10794288 C allele, the rs10902088 T allele and the rs7103978 G allele (<it>P </it>= 0.030, 0.013 and 0.040, respectively). In addition, the rs10794288 C allele and the rs10902088 T allele were also less abundant in patients with infertility versus fertile ones (<it>P </it>= 0.015 and 0.024, respectively). Haplotype analysis of the endometriosis associated SNPs in <it>MUC2 </it>also showed significantly association between the most common haplotypes and endometriosis or endometriosis-related infertility.</p> <p>Conclusions</p> <p><it>MUC2 </it>polymorphisms, especially rs10794288 and rs10902088, are associated with endometriosis as well as endometriosis-related infertility. Our data present MUC2 as a new candidate involved in development of endometriosis and related infertility in Taiwanese Han women.</p

    Studying the Underlying Event in Drell-Yan and High Transverse Momentum Jet Production at the Tevatron

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    We study the underlying event in proton-antiproton collisions by examining the behavior of charged particles (transverse momentum pT > 0.5 GeV/c, pseudorapidity |\eta| < 1) produced in association with large transverse momentum jets (~2.2 fb-1) or with Drell-Yan lepton-pairs (~2.7 fb-1) in the Z-boson mass region (70 < M(pair) < 110 GeV/c2) as measured by CDF at 1.96 TeV center-of-mass energy. We use the direction of the lepton-pair (in Drell-Yan production) or the leading jet (in high-pT jet production) in each event to define three regions of \eta-\phi space; toward, away, and transverse, where \phi is the azimuthal scattering angle. For Drell-Yan production (excluding the leptons) both the toward and transverse regions are very sensitive to the underlying event. In high-pT jet production the transverse region is very sensitive to the underlying event and is separated into a MAX and MIN transverse region, which helps separate the hard component (initial and final-state radiation) from the beam-beam remnant and multiple parton interaction components of the scattering. The data are corrected to the particle level to remove detector effects and are then compared with several QCD Monte-Carlo models. The goal of this analysis is to provide data that can be used to test and improve the QCD Monte-Carlo models of the underlying event that are used to simulate hadron-hadron collisions.Comment: Submitted to Phys.Rev.

    Measurement of the W+WW^+W^- Production Cross Section and Search for Anomalous WWγWW\gamma and WWZWWZ Couplings in ppˉp \bar p Collisions at s=1.96\sqrt{s} = 1.96 TeV

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    This Letter describes the current most precise measurement of the WW boson pair production cross section and most sensitive test of anomalous WWγWW\gamma and WWZWWZ couplings in ppˉp \bar p collisions at a center-of-mass energy of 1.96 TeV. The WWWW candidates are reconstructed from decays containing two charged leptons and two neutrinos, where the charged leptons are either electrons or muons. Using data collected by the CDF II detector from 3.6 fb1^{-1} of integrated luminosity, a total of 654 candidate events are observed with an expected background contribution of 320±47320 \pm 47 events. The measured total cross section is σ(ppˉW+W+X)=12.1±0.9(stat)1.4+1.6(syst)\sigma (p \bar p \to W^+ W^- + X) = 12.1 \pm 0.9 \textrm{(stat)} ^{+1.6}_{-1.4} \textrm{(syst)} pb, which is in good agreement with the standard model prediction. The same data sample is used to place constraints on anomalous WWγWW\gamma and WWZWWZ couplings.Comment: submitted to Phys. Rev. Let

    Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

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    Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

    Feebly-interacting particles: FIPs 2020 workshop report

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    With the establishment and maturation of the experimental programs searching for new physics with sizeable couplings at the LHC, there is an increasing interest in the broader particle and astrophysics community for exploring the physics of light and feebly-interacting particles as a paradigm complementary to a New Physics sector at the TeV scale and beyond. FIPs 2020 has been the first workshop fully dedicated to the physics of feebly-interacting particles and was held virtually from 31 August to 4 September 2020. The workshop has gathered together experts from collider, beam dump, fixed target experiments, as well as from astrophysics, axions/ALPs searches, current/future neutrino experiments, and dark matter direct detection communities to discuss progress in experimental searches and underlying theory models for FIPs physics, and to enhance the cross-fertilisation across different fields. FIPs 2020 has been complemented by the topical workshop Physics Beyond Colliders meets theory, held at CERN from 7 June to 9 June 2020. This document presents the summary of the talks presented at the workshops and the outcome of the subsequent discussions held immediately after. It aims to provide a clear picture of this blooming field and proposes a few recommendations for the next round of experimental results

    Corporate boards and the performance of Asian firms: A meta-analysis

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    The prevalence of ownership concentration in Asian firms presents a challenge to the influential agency theory-based understanding of the role of corporate boards. In this paper we develop and test hypotheses about board attributes and firm performance that reflect Asian institutional conditions. We present the first meta-analysis of the relationship between board attributes and performance of Asian firms using a varied set of meta-analytical techniques on a database of 86 studies covering nine Asian countries. First, we find that board structure and composition preferences are influenced by the identity of the concentrated owner. Second, consistent with US data, we find very limited evidence of a direct relationship between board attributes and firm financial performance in the Asian context. Third, we find that the relationship between board structure and composition and firm performance is mediated by the revealed strategic preferences of Asian firms specifically by the level of R&D investment

    The Forward Physics Facility at the High-Luminosity LHC

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    High energy collisions at the High-Luminosity Large Hadron Collider (LHC) produce a large number of particles along the beam collision axis, outside of the acceptance of existing LHC experiments. The proposed Forward Physics Facility (FPF), to be located several hundred meters from the ATLAS interaction point and shielded by concrete and rock, will host a suite of experiments to probe standard model (SM) processes and search for physics beyond the standard model (BSM). In this report, we review the status of the civil engineering plans and the experiments to explore the diverse physics signals that can be uniquely probed in the forward region. FPF experiments will be sensitive to a broad range of BSM physics through searches for new particle scattering or decay signatures and deviations from SM expectations in high statistics analyses with TeV neutrinos in this low-background environment. High statistics neutrino detection will also provide valuable data for fundamental topics in perturbative and non-perturbative QCD and in weak interactions. Experiments at the FPF will enable synergies between forward particle production at the LHC and astroparticle physics to be exploited. We report here on these physics topics, on infrastructure, detector, and simulation studies, and on future directions to realize the FPF's physics potential
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