373 research outputs found

    Estimating Prognosis and Frailty in Persons Aged ≥75 Years in the Emergency Department: Further Validation of Dynamic Silver Code.

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    OBJECTIVES To assess concurrent validity of the Dynamic Silver Code (DSC), a tool based on administrative data that predicts prognosis in older adults accessing the emergency department (ED), in terms of association with markers of poor functional and cognitive status. DESIGN Cross-sectional. SETTING AND PARTICIPANTS Data were obtained in the AIDEA study, which enrolled a cohort of ≥75-year-old patients, accessing the ED of 2 hospitals in Florence, Italy. METHODS The DSC score and classes (I to IV, corresponding to an increasing risk of death) were obtained from administrative data. Information on health and functional status prior to ED access were collected from face-to-face, direct, or proxy interviews. The 4AT test was administered to screen for possible delirium. Bivariate comparisons of the prevalence of each functional and cognitive marker across 4 DSC classes were performed. Multinomial logistic regression was used to assess the multivariable risk of being in II, III, or IV DSC class vs I. RESULTS Among 3358 participants (mean age 83 years, men 44%), 32.9%, 30.3%, 19.5%, and 17.2% were in DSC class I, II, III, and IV. Preadmission abnormal functional and cognitive conditions, and delirium in the ED, were increasingly more common from DSC class I through IV (P < .001). In particular, the prevalence of total inability to walk increased from 2.9% (class I) to 23.4% (class IV). In multivariable analyses, this was the strongest predictor of being in progressively worse DSC classes, whereas feeling of exhaustion, reporting of serious falls, weight loss, and severe memory loss or diagnosis of dementia gave some contribution. CONCLUSIONS AND IMPLICATIONS The ability of the DSC to predict survival in older persons appears to rely on its prevailing association with markers of functional impairment. These results may support clinical use of the tool

    Pseudorapidity densities of charged particles with transverse momentum thresholds in pp collisions at √ s = 5.02 and 13 TeV

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    The pseudorapidity density of charged particles with minimum transverse momentum (pT) thresholds of 0.15, 0.5, 1, and 2 GeV/c is measured in pp collisions at the center of mass energies of √s=5.02 and 13 TeV with the ALICE detector. The study is carried out for inelastic collisions with at least one primary charged particle having a pseudorapidity (η) within 0.8pT larger than the corresponding threshold. In addition, measurements without pT-thresholds are performed for inelastic and nonsingle-diffractive events as well as for inelastic events with at least one charged particle having |η|2GeV/c), highlighting the importance of such measurements for tuning event generators. The new measurements agree within uncertainties with results from the ATLAS and CMS experiments obtained at √s=13TeV.

    Measurement of inclusive J/ψ\psi pair production cross section in pp collisions at s=13\sqrt{s} = 13 TeV

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    International audienceThe production cross section of inclusive J/ψ\psi pairs in pp collisions at a centre-of-mass energy s=13\sqrt{s} = 13 TeV is measured with ALICE. The measurement is performed for J/ψ\psi in the rapidity interval 2.502.5 0. The production cross section of inclusive J/ψ\psi pairs is reported to be 10.3±2.3(stat.)±1.3(syst.)10.3 \pm 2.3 {\rm (stat.)} \pm 1.3 {\rm (syst.)} nb in this kinematic interval. The contribution from non-prompt J/ψ\psi (i.e. originated from beauty-hadron decays) to the inclusive sample is evaluated. The results are discussed and compared with data

    Inclusive and multiplicity dependent production of electrons from heavy-flavour hadron decays in pp and p-Pb collisions

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    International audienceMeasurements of the production of electrons from heavy-flavour hadron decays in pp collisions at s=13\sqrt{s} = 13 TeV at midrapidity with the ALICE detector are presented down to a transverse momentum (pTp_{\rm T}) of 0.2 GeV/c/c and up to pT=35p_{\rm T} = 35 GeV/c/c, which is the largest momentum range probed for inclusive electron measurements in ALICE. In p-Pb collisions, the production cross section and the nuclear modification factor of electrons from heavy-flavour hadron decays are measured in the pTp_{\rm T} range 0.5<pT<260.5 < p_{\rm T} < 26 GeV/c/c at sNN=8.16\sqrt{s_{\rm NN}} = 8.16 TeV. The nuclear modification factor is found to be consistent with unity within the statistical and systematic uncertainties. In both collision systems, first measurements of the yields of electrons from heavy-flavour hadron decays in different multiplicity intervals normalised to the multiplicity-integrated yield (self-normalised yield) at midrapidity are reported as a function of the self-normalised charged-particle multiplicity estimated at midrapidity. The self-normalised yields in pp and p-Pb collisions grow faster than linear with the self-normalised multiplicity. A strong pTp_{\rm T} dependence is observed in pp collisions, where the yield of high-pTp_{\rm T} electrons increases faster as a function of multiplicity than the one of low-pTp_{\rm T} electrons. The measurement in p-Pb collisions shows no pTp_{\rm T} dependence within uncertainties. The self-normalised yields in pp and p-Pb collisions are compared with measurements of other heavy-flavour, light-flavour, and strange particles, and with Monte Carlo simulations

    Observation of medium-induced yield enhancement and acoplanarity broadening of low-pTp_\mathrm{T} jets from measurements in pp and central Pb-Pb collisions at sNN=5.02\sqrt{s_{\rm NN}}=5.02 TeV

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    International audienceThe ALICE Collaboration reports the measurement of semi-inclusive distributions of charged-particle jets recoiling from a high transverse momentum (high pTp_{\rm T}) hadron trigger in proton-proton and central Pb-Pb collisions at sNN=5.02\sqrt{s_{\rm NN}} = 5.02 TeV. A data-driven statistical method is used to mitigate the large uncorrelated background in central Pb-Pb collisions. Recoil jet distributions are reported for jet resolution parameter R=0.2R=0.2, 0.4, and 0.5 in the range 7<pT,jet<1407 < p_{\rm T,jet} < 140 GeV/c/c and trigger-recoil jet azimuthal separation π/2<Δφ<π\pi/2 < \Delta\varphi < \pi. The measurements exhibit a marked medium-induced jet yield enhancement at low pTp_{\rm T} and at large azimuthal deviation from Δφπ\Delta\varphi\sim\pi. The enhancement is characterized by its dependence on Δφ\Delta\varphi, which has a slope that differs from zero by 4.7σ\sigma. Comparisons to model calculations incorporating different formulations of jet quenching are reported. These comparisons indicate that the observed yield enhancement arises from the response of the QGP medium to jet propagation

    Probing the Chiral Magnetic Wave with charge-dependent flow measurements in Pb-Pb collisions at the LHC

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    International audienceThe Chiral Magnetic Wave (CMW) phenomenon is essential to provide insights into the strong interaction in QCD, the properties of the quark-gluon plasma, and the topological characteristics of the early universe, offering a deeper understanding of fundamental physics in high-energy collisions. Measurements of the charge-dependent anisotropic flow coefficients are studied in Pb-Pb collisions at center-of-mass energy per nucleon-nucleon collision sNN=\sqrt{s_{\mathrm{NN}}}= 5.02 TeV to probe the CMW. In particular, the slope of the normalized difference in elliptic (v2v_{2}) and triangular (v3v_{3}) flow coefficients of positively and negatively charged particles as a function of their event-wise normalized number difference, is reported for inclusive and identified particles. The slope r3Normr_{3}^{\rm Norm} is found to be larger than zero and to have a magnitude similar to r2Normr_{2}^{\rm Norm}, thus pointing to a large background contribution for these measurements. Furthermore, r2Normr_{2}^{\rm Norm} can be described by a blast wave model calculation that incorporates local charge conservation. In addition, using the event shape engineering technique yields a fraction of CMW (fCMWf_{\rm CMW}) contribution to this measurement which is compatible with zero. This measurement provides the very first upper limit for fCMWf_{\rm CMW}, and in the 10-60% centrality interval it is found to be 26% (38%) at 95% (99.7%) confidence level

    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)

    Forward rapidity J/ψ production as a function of charged-particle multiplicity in pp collisions at s \sqrt{s} = 5.02 and 13 TeV

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    International audienceThe production of J/ψ is measured as a function of charged-particle multiplicity at forward rapidity in proton-proton (pp) collisions at center-of-mass energies s \sqrt{s} = 5.02 and 13 TeV. The J/ψ mesons are reconstructed via their decay into dimuons in the rapidity interval (2.5 < y < 4.0), whereas the charged-particle multiplicity density (dNch_{ch}/dη) is measured at midrapidity (|η| < 1). The production rate as a function of multiplicity is reported as the ratio of the yield in a given multiplicity interval to the multiplicity-integrated one. This observable shows a linear increase with charged-particle multiplicity normalized to the corresponding average value for inelastic events (dNch_{ch}/dη/〈dNch_{ch}/dη〉), at both the colliding energies. Measurements are compared with available ALICE results at midrapidity and theoretical model calculations. First measurement of the mean transverse momentum (〈pT_{T}〉) of J/ψ in pp collisions exhibits an increasing trend as a function of dNch_{ch}/dη/〈dNch_{ch}/dη〉 showing a saturation towards high charged-particle multiplicities.[graphic not available: see fulltext

    Measurement of (anti)alpha production in central Pb-Pb collisions at sNN\sqrt{s_{\rm NN}} = 5.02 TeV

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    International audienceIn this letter, measurements of (anti)alpha production in central (0-10%) Pb-Pb collisions at a center-of-mass energy per nucleon-nucleon pair of sNN\sqrt{s_{\rm NN}} = 5.02 TeV are presented, including the first measurement of an antialpha transverse-momentum spectrum. Owing to its large mass, (anti)alpha production yields and transverse-momentum spectra are of particular interest because they provide a stringent test of particle production models. The averaged antialpha and alpha spectrum is included into a common blast-wave fit with lighter particles, indicating that the (anti)alpha also participates in the collective expansion of the medium created in the collision. A blast-wave fit including only protons, (anti)alpha, and other light nuclei results in a similar flow velocity as the fit that includes all particles. A similar flow velocity, but a significantly larger kinetic freeze-out temperature is obtained when only protons and light nuclei are included in the fit. The coalescence parameter B4B_4 is well described by calculations from a statistical hadronization model but significantly underestimated by calculations assuming nucleus formation via coalescence of nucleons. Similarly, the (anti)alpha-to-proton ratio is well described by the statistical hadronization model. On the other hand, coalescence calculations including approaches with different implementations of the (anti)alpha substructure tend to underestimate the data
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