50 research outputs found

    Elliptic flow of charged particles in Pb-Pb collisions at 2.76 TeV

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    We report the first measurement of charged particle elliptic flow in Pb-Pb collisions at 2.76 TeV with the ALICE detector at the CERN Large Hadron Collider. The measurement is performed in the central pseudorapidity region (|η\eta|<0.8) and transverse momentum range 0.2< pTp_{\rm T}< 5.0 GeV/cc. The elliptic flow signal v2_2, measured using the 4-particle correlation method, averaged over transverse momentum and pseudorapidity is 0.087 ±\pm 0.002 (stat) ±\pm 0.004 (syst) in the 40-50% centrality class. The differential elliptic flow v2(pT)_2(p_{\rm T}) reaches a maximum of 0.2 near pTp_{\rm T} = 3 GeV/cc. Compared to RHIC Au-Au collisions at 200 GeV, the elliptic flow increases by about 30%. Some hydrodynamic model predictions which include viscous corrections are in agreement with the observed increase.Comment: 10 pages, 4 captioned figures, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/389

    Higher harmonic anisotropic flow measurements of charged particles in Pb-Pb collisions at 2.76 TeV

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    We report on the first measurement of the triangular v3v_3, quadrangular v4v_4, and pentagonal v5v_5 charged particle flow in Pb-Pb collisions at 2.76 TeV measured with the ALICE detector at the CERN Large Hadron Collider. We show that the triangular flow can be described in terms of the initial spatial anisotropy and its fluctuations, which provides strong constraints on its origin. In the most central events, where the elliptic flow v2v_2 and v3v_3 have similar magnitude, a double peaked structure in the two-particle azimuthal correlations is observed, which is often interpreted as a Mach cone response to fast partons. We show that this structure can be naturally explained from the measured anisotropic flow Fourier coefficients.Comment: 10 pages, 4 figures, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/387

    Genetic mechanisms of critical illness in COVID-19.

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    Host-mediated lung inflammation is present1, and drives mortality2, in the critical illness caused by coronavirus disease 2019 (COVID-19). Host genetic variants associated with critical illness may identify mechanistic targets for therapeutic development3. Here we report the results of the GenOMICC (Genetics Of Mortality In Critical Care) genome-wide association study in 2,244 critically ill patients with COVID-19 from 208 UK intensive care units. We have identified and replicated the following new genome-wide significant associations: on chromosome 12q24.13 (rs10735079, P = 1.65 × 10-8) in a gene cluster that encodes antiviral restriction enzyme activators (OAS1, OAS2 and OAS3); on chromosome 19p13.2 (rs74956615, P = 2.3 × 10-8) near the gene that encodes tyrosine kinase 2 (TYK2); on chromosome 19p13.3 (rs2109069, P = 3.98 ×  10-12) within the gene that encodes dipeptidyl peptidase 9 (DPP9); and on chromosome 21q22.1 (rs2236757, P = 4.99 × 10-8) in the interferon receptor gene IFNAR2. We identified potential targets for repurposing of licensed medications: using Mendelian randomization, we found evidence that low expression of IFNAR2, or high expression of TYK2, are associated with life-threatening disease; and transcriptome-wide association in lung tissue revealed that high expression of the monocyte-macrophage chemotactic receptor CCR2 is associated with severe COVID-19. Our results identify robust genetic signals relating to key host antiviral defence mechanisms and mediators of inflammatory organ damage in COVID-19. Both mechanisms may be amenable to targeted treatment with existing drugs. However, large-scale randomized clinical trials will be essential before any change to clinical practice

    Long-range angular correlations on the near and away side in p&#8211;Pb collisions at

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    Diagnostic Tests for Female Bladder Outlet Obstruction: A Systematic Review from the European Association of Urology Non-neurogenic Female LUTS Guidelines Panel

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    Context: Female bladder outlet obstruction (fBOO) is a relatively uncommon condition compared with its male counterpart. Several criteria have been proposed to define fBOO, but the comparative diagnostic accuracy of these remains uncertain. Objective: To identify and compare different tests to diagnose fBOO through a systematic review process. Evidence acquisition: A systematic review of the literature was performed according to the Cochrane Handbook and Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) checklist. The EMBASE/MEDLINE/Cochrane databases were searched up to August 4, 2020. Studies on women ≥18 yr of age with suspected bladder outlet obstruction (BOO) involving diagnostic tests were included. Pressure-flow studies or fluoroscopy was used as the reference standard where possible. Two reviewers independently screened all articles, searched reference lists of retrieved articles, and performed data extraction. The risk of bias was assessed using Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2). Evidence synthesis: Overall, 28 nonrandomised studies involving 10 248 patients were included in the qualitative analysis. There was significant heterogeneity regarding the characteristics of women included in BOO cohorts (ie, mixed cohorts including both anatomical and functional BOO). Pressure-flow studies ± fluoroscopy was evaluated in 25 studies. Transperineal Doppler ultrasound was used to evaluate bladder neck dynamics in two studies. One study tested the efficacy of transvaginal ultrasound. The urodynamic definition of fBOO also varied amongst studies with different parameters and thresholds used, which precluded a meta-analysis. Three studies derived nomograms using the maximum flow rate (Qmax) and voiding detrusor pressure at Qmax. The sensitivity, specificity, and overall accuracy ranges were 54.6–92.5%, 64.6–93.9%, and 64.1–92.2%, respectively. Conclusions: The available evidence on diagnostic tests for fBOO is limited and heterogeneous. Pressure-flow studies ± fluoroscopy remains the current standard for diagnosing fBOO. Patient summary: Evidence on tests used to diagnose female bladder outlet obstruction was reviewed. The most common test used was pressure-flow studies ± fluoroscopy, which remains the current standard for diagnosing bladder outlet obstruction in women. Take Home Message: The available evidence on diagnostic tests for female bladder outlet obstruction is limited and heterogeneous. The most common test used was video-urodynamics, which remains the current standard for diagnosing bladder outlet obstruction in women. © 2021 European Association of Urolog

    Where Brain, Body and World Collide

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    The production cross section of electrons from semileptonic decays of beauty hadrons was measured at mid-rapidity (|y| &lt; 0.8) in the transverse momentum range 1 &lt; pt &lt; 8 Gev/c with the ALICE experiment at the CERN LHC in pp collisions at a center of mass energy sqrt{s} = 7 TeV using an integrated luminosity of 2.2 nb^{-1}. Electrons from beauty hadron decays were selected based on the displacement of the decay vertex from the collision vertex. A perturbative QCD calculation agrees with the measurement within uncertainties. The data were extrapolated to the full phase space to determine the total cross section for the production of beauty quark-antiquark pairs
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