604 research outputs found

    Perioperative mortality after hemiarthroplasty related to fixation method: A study based on the Australian Orthopaedic Association National Joint Replacement Registry

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    Background and purpose: The appropriate fixation method for hemiarthroplasty of the hip as it relates to implant survivorship and patient mortality is a matter of ongoing debate. We examined the influence of fixation method on revision rate and mortality.----- ----- Methods: We analyzed approximately 25,000 hemiarthroplasty cases from the AOA National Joint Replacement Registry. Deaths at 1 day, 1 week, 1 month, and 1 year were compared for all patients and among subgroups based on implant type.----- ----- Results: Patients treated with cemented monoblock hemiarthroplasty had a 1.7-times higher day-1 mortality compared to uncemented monoblock components (p < 0.001). This finding was reversed by 1 week, 1 month, and 1 year after surgery (p < 0.001). Modular hemiarthroplasties did not reveal a difference in mortality between fixation methods at any time point.----- ----- Interpretation: This study shows lower (or similar) overall mortality with cemented hemiarthroplasty of the hip

    Exuberant fibroblast activity compromises lung function via ADAMTS4

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    Severe respiratory infections can result in acute respiratory distress syndrome (ARDS) . There are no effective pharmacological therapies that have been shown to improve outcomes for patients with ARDS. Although the host inflammatory response limits spread of and eventually clears the pathogen, immunopathology is a major contributor to tissue damage and ARDS . Here we demonstrate that respiratory viral infection induces distinct fibroblast activation states, which we term extracellular matrix (ECM)-synthesizing, damage-responsive and interferon-responsive states. We provide evidence that excess activity of damage-responsive lung fibroblasts drives lethal immunopathology during severe influenza virus infection. By producing ECM-remodelling enzymes-in particular the ECM protease ADAMTS4-and inflammatory cytokines, damage-responsive fibroblasts modify the lung microenvironment to promote robust immune cell infiltration at the expense of lung function. In three cohorts of human participants, the levels of ADAMTS4 in the lower respiratory tract were associated with the severity of infection with seasonal or avian influenza virus. A therapeutic agent that targets the ECM protease activity of damage-responsive lung fibroblasts could provide a promising approach to preserving lung function and improving clinical outcomes following severe respiratory infections

    CT coronary angiography in patients with suspected angina due to coronary heart disease (SCOT-HEART): an open-label,parallel-group, multicentre trial

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    Background The benefi t of CT coronary angiography (CTCA) in patients presenting with stable chest pain has not been systematically studied. We aimed to assess the eff ect of CTCA on the diagnosis, management, and outcome of patients referred to the cardiology clinic with suspected angina due to coronary heart disease. Methods In this prospective open-label, parallel-group, multicentre trial, we recruited patients aged 18–75 years referred for the assessment of suspected angina due to coronary heart disease from 12 cardiology chest pain clinics across Scotland. We randomly assigned (1:1) participants to standard care plus CTCA or standard care alone. Randomisation was done with a web-based service to ensure allocation concealment. The primary endpoint was certainty of the diagnosis of angina secondary to coronary heart disease at 6 weeks. All analyses were intention to treat, and patients were analysed in the group they were allocated to, irrespective of compliance with scanning. This study is registered with ClinicalTrials.gov, number NCT01149590. Findings Between Nov 18, 2010, and Sept 24, 2014, we randomly assigned 4146 (42%) of 9849 patients who had been referred for assessment of suspected angina due to coronary heart disease. 47% of participants had a baseline clinic diagnosis of coronary heart disease and 36% had angina due to coronary heart disease. At 6 weeks, CTCA reclassifi ed the diagnosis of coronary heart disease in 558 (27%) patients and the diagnosis of angina due to coronary heart disease in 481 (23%) patients (standard care 22 [1%] and 23 [1%]; p<0·0001). Although both the certainty (relative risk [RR] 2·56, 95% CI 2·33–2·79; p<0·0001) and frequency of coronary heart disease increased (1·09, 1·02–1·17; p=0·0172), the certainty increased (1·79, 1·62–1·96; p<0·0001) and frequency seemed to decrease (0·93, 0·85–1·02; p=0·1289) for the diagnosis of angina due to coronary heart disease. This changed planned investigations (15% vs 1%; p<0·0001) and treatments (23% vs 5%; p<0·0001) but did not aff ect 6-week symptom severity or subsequent admittances to hospital for chest pain. After 1·7 years, CTCA was associated with a 38% reduction in fatal and nonfatal myocardial infarction (26 vs 42, HR 0·62, 95% CI 0·38–1·01; p=0·0527), but this was not signifi cant. Interpretation In patients with suspected angina due to coronary heart disease, CTCA clarifi es the diagnosis, enables targeting of interventions, and might reduce the future risk of myocardial infarction. Funding The Chief Scientist Offi ce of the Scottish Government Health and Social Care Directorates funded the trial with supplementary awards from Edinburgh and Lothian’s Health Foundation Trust and the Heart Diseases Research Fund

    Inclusive quarkonium production in pp collisions at s=5.02\sqrt{s} = 5.02 TeV

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    This article reports on the inclusive production cross section of several quarkonium states, J/ψ\mathrm{J}/\psi, ψ(2S)\psi {\rm (2S)}, Υ(1S)\Upsilon\rm(1S), Υ(2S)\Upsilon\rm(2S), and Υ(3S)\Upsilon\rm(3S), measured with the ALICE detector at the LHC, in \pp collisions at s=5.02\sqrt{s} = 5.02 TeV. The analysis is performed in the dimuon decay channel at forward rapidity (2.5<y<42.5 < y < 4). The measured cross sections, assuming unpolarized quarkonia, are: σJ/ψ=5.88±0.03±0.34 μ\sigma_{\mathrm{J}/\psi} = 5.88 \pm 0.03 \pm 0.34\ \mub, σψ(2S)=0.87±0.06±0.10 μ\sigma_{\psi {\rm (2S)}} = 0.87 \pm 0.06 \pm 0.10\ \mub, σΥ(1S)=45.5±3.9±3.5\sigma_{\Upsilon\rm(1S)} = 45.5 \pm 3.9 \pm 3.5 nb, σΥ(2S)=22.4±3.2±2.7\sigma_{\Upsilon\rm(2S)} = 22.4 \pm 3.2 \pm 2.7 nb, and σΥ(3S)=4.9±2.2±1.0\sigma_{\Upsilon\rm(3S)} = 4.9 \pm 2.2 \pm 1.0 nb, where the first (second) uncertainty is the statistical (systematic) one. The transverse-momentum (pTp_{\rm T}) and rapidity (yy) differential cross sections for J/ψ\mathrm{J}/\psi, ψ(2S)\psi {\rm (2S)}, Υ(1S)\Upsilon\rm(1S), and the ψ(2S)\psi {\rm (2S)}-to-J/ψ\mathrm{J}/\psi cross section ratios are presented. For the first time, the cross sections of the three Υ\Upsilon states, as well as the ψ(2S)\psi {\rm (2S)} one as a function of pTp_{\rm T} and yy, are measured at s=5.02\sqrt{s} = 5.02 TeV at forward rapidity. These measurements also significantly extend the J/ψ\mathrm{J}/\psipTp_{\rm T} reach with respect to previously published results. A comparison with ALICE measurements in pp collisions at s=2.76\sqrt{s} = 2.76, 7, 8, and 13 TeV is presented and the energy dependence of quarkonium production cross sections is discussed. Finally, the results are compared with the predictions from several production models

    Neutral to charged kaon yield fluctuations in Pb – Pb collisions at sNN\sqrt{s_{\rm NN}} = 2.76 TeV

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    We present the first measurement of event-by-event fluctuations in the kaon sector in Pb – Pb collisions at sNN\sqrt{s_{\rm NN}} = 2.76 TeV with the ALICE detector at the LHC. The robust fluctuation correlator νdyn_{dyn} is used to evaluate the magnitude of fluctuations of the relative yields of neutral and charged kaons, as well as the relative yields of charged kaons, as a function of collision centrality and selected kinematic ranges. While the correlator νdyn_{dyn}[K+^+,K^−] exhibits a scaling approximately in inverse proportion of the charged particle multiplicity, νdyn_{dyn}[KS0_S^0,K±^\pm] features a significant deviation from such scaling. Within uncertainties, the value of νdyn_{dyn}[KS0_S^0,K±^\pm] is independent of the selected transverse momentum interval, while it exhibits a pseudorapidity dependence. The results are compared with HIJING, AMPT and EPOS–LHC predictions, and are further discussed in the context of the possible production of disoriented chiral condensates in central Pb – Pb collisions

    First study of the two-body scattering involving charm hadrons

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    This article presents the first measurement of the interaction between charm hadrons and nucleons. The two-particle momentum correlations of pDpD^- and pˉD+\bar{p}D^+ pairs are measured by the ALICE Collaboration in high-multiplicity pp collisions at s\sqrt{s} = 13 TeV. The data are compatible with the Coulomb-only interaction hypothesis within (1.1–1.5)σ. The level of agreement slightly improves if an attractive nucleon (N)Dˉ(N)\bar{D} strong interaction is considered, in contrast to most model predictions which suggest an overall repulsive interaction. This measurement allows for the first time an estimation of the 68% confidence level interval for the isospin I=0 inverse scattering length of the NDˉN\bar{D} state f0,I=01f_{0,I=0}^{-1}∈[-0.4,0.9] fm1^{-1}, assuming negligible interaction for the isospin I=1 channel

    Measurement of the angle between jet axes in Pb-Pb collisions at sNN=5.02\sqrt{s_{\rm NN}} = 5.02 TeV

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    International audienceThis letter presents the first measurement of the angle between different jet axes (denoted as ΔR{\Delta}R) in Pb-Pb collisions. The measurement is carried out in the 0-10% most-central events at sNN=5.02\sqrt{s_{\rm NN}} = 5.02 TeV. Jets are assembled by clustering charged particles at midrapidity using the anti-kTk_{\rm T} algorithm with resolution parameters R=0.2R=0.2 and 0.40.4 and transverse momenta in the intervals 40<pTchjet<14040 < p_{\rm T}^{\rm ch jet} < 140 GeV/cc and 80<pTchjet<14080 < p_{\rm T}^{\rm ch jet} < 140 GeV/cc, respectively. Measurements at these low transverse momenta enhance the sensitivity to quark-gluon plasma (QGP) effects. A comparison to models implementing various mechanisms of jet energy loss in the QGP shows that the observed narrowing of the Pb-Pb distribution relative to pp can be explained if quark-initiated jets are more likely to emerge from the medium than gluon-initiated jets. These new measurements discard intra-jet pTp_{\rm T} broadening as described in a model calculation with the BDMPS formalism as the main mechanism of energy loss in the QGP. The data are sensitive to the angular scale at which the QGP can resolve two independent splittings, favoring mechanisms that incorporate incoherent energy loss

    First measurement of the t|t|-dependence of incoherent J/ψ\psi photonuclear production

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    International audienceThe first measurement of the cross section for incoherent photonuclear production of J/ψ\psi vector meson as a function of the Mandelstam t|t| variable is presented. The measurement was carried out with the ALICE detector at midrapidity, y<0.8|y|<0.8, using ultra-peripheral collisions of Pb nuclei at a centre-of-mass energy per nucleon pair sNN=5.02\sqrt{s_{\mathrm{NN}}} = 5.02 TeV. This rapidity interval corresponds to a Bjorken-xx range (0.3(0.3-1.4)×1031.4)\times 10^{-3}. Cross sections are reported in five t|t| intervals in the range 0.04<t<10.04<|t|<1~GeV2^2 and compared to the predictions of different models. Models that ignore quantum fluctuations of the gluon density in the colliding hadron predict a t|t|-dependence of the cross section much steeper than in data. The inclusion of such fluctuations in the same models provides a better description of the data

    Charged-particle production as a function of the relative transverse activity classifier in pp, p-Pb, and Pb-Pb collisions at the LHC

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    International audienceMeasurements of charged-particle production in pp, p-Pb, and Pb-Pb collisions in the toward, away, and transverse regions with the ALICE detector are discussed. These regions are defined event-by-event relative to the azimuthal direction of the charged trigger particle, which is the reconstructed particle with the largest transverse momentum (pTtrigp_{\mathrm{T}}^{\rm trig}) in the range 8<pTtrig<158<p_{\mathrm{T}}^{\rm trig}<15 GeV/c/c. The toward and away regions contain the primary and recoil jets, respectively; both regions are accompanied by the underlying event (UE). In contrast, the transverse region perpendicular to the direction of the trigger particle is dominated by the so-called UE dynamics, and includes also contributions from initial- and final-state radiation. The relative transverse activity classifier, RT=NchT/NchTR_{\mathrm{T}}=N_{\mathrm{ch}}^{\mathrm{T}}/\langle N_{\mathrm{ch}}^{\mathrm{T}}\rangle, is used to group events according to their UE activity, where NchTN_{\mathrm{ch}}^{\mathrm{T}} is the charged-particle multiplicity per event in the transverse region and NchT\langle N_{\mathrm{ch}}^{\mathrm{T}}\rangle is the mean value over the whole analysed sample. The energy dependence of the RTR_{\mathrm{T}} distributions in pp collisions at s=2.76\sqrt{s}=2.76, 5.02, 7, and 13 TeV is reported, exploring the Koba-Nielsen-Olesen (KNO) scaling properties of the multiplicity distributions. The first measurements of charged-particle pTp_{\rm T} spectra as a function of RTR_{\mathrm{T}} in the three azimuthal regions in pp, p-Pb, and Pb-Pb collisions at sNN=5.02\sqrt{s_{\rm NN}}=5.02 TeV are also reported. Data are compared with predictions obtained from the event generators PYTHIA 8 and EPOS LHC. This set of measurements is expected to contribute to the understanding of the origin of collective-like effects in small collision systems (pp and p-Pb)

    Charm production and fragmentation fractions at midrapidity in pp collisions at s=13\sqrt{s} = 13 TeV

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    International audienceMeasurements of the production cross sections of prompt D0{\rm D^0}, D+{\rm D^+}, D+{\rm D^{\ast +}}, Ds+{\rm D_s^+}, Λc+{\rm \Lambda_{c}^{+}}, and Ξc+{\rm \Xi_{c}^{+}} charm hadrons at midrapidity in proton-proton collisions at s=13\sqrt{s}=13 TeV with the ALICE detector are presented. The D-meson cross sections as a function of transverse momentum (pTp_{\rm T}) are provided with improved precision and granularity. The ratios of pTp_{\rm T}-differential meson production cross sections based on this publication and on measurements at different rapidity and collision energy provide a constraint on gluon parton distribution functions at low values of Bjorken-xx (10510410^{-5}-10^{-4}). The measurements of Λc+{\rm \Lambda_{c}^{+}} (Ξc+{\rm \Xi_{c}^{+}}) baryon production extend the measured pTp_{\rm T} intervals down to pT=0(3)p_{\rm T}=0(3)~GeV/c/c. These measurements are used to determine the charm-quark fragmentation fractions and the cc{\rm c\overline{c}} production cross section at midrapidity (y<0.5|y|<0.5) based on the sum of the cross sections of the weakly-decaying ground-state charm hadrons D0{\rm D^0}, D+{\rm D^+}, Ds+{\rm D_s^+}, Λc+{\rm \Lambda_{c}^{+}}, Ξc0{\rm \Xi_{c}^{0}} and, for the first time, Ξc+{\rm \Xi_{c}^{+}}, and of the strongly-decaying J/psipsi mesons. The first measurements of Ξc+{\rm \Xi_{c}^{+}} and Σc0,++{\rm \Sigma_{c}^{0,++}} fragmentation fractions at midrapidity are also reported. A significantly larger fraction of charm quarks hadronising to baryons is found compared to e+^+e^- and ep collisions. The cc{\rm c\overline{c}} production cross section at midrapidity is found to be at the upper bound of state-of-the-art perturbative QCD calculations
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