34 research outputs found

    Operation and performance of the ATLAS Tile Calorimeter in Run 1

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    The Tile Calorimeter is the hadron calorimeter covering the central region of the ATLAS experiment at the Large Hadron Collider. Approximately 10,000 photomultipliers collect light from scintillating tiles acting as the active material sandwiched between slabs of steel absorber. This paper gives an overview of the calorimeter’s performance during the years 2008–2012 using cosmic-ray muon events and proton–proton collision data at centre-of-mass energies of 7 and 8TeV with a total integrated luminosity of nearly 30 fb−1. The signal reconstruction methods, calibration systems as well as the detector operation status are presented. The energy and time calibration methods performed excellently, resulting in good stability of the calorimeter response under varying conditions during the LHC Run 1. Finally, the Tile Calorimeter response to isolated muons and hadrons as well as to jets from proton–proton collisions is presented. The results demonstrate excellent performance in accord with specifications mentioned in the Technical Design Report

    Effects of pre-operative isolation on postoperative pulmonary complications after elective surgery: an international prospective cohort study

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    We aimed to determine the impact of pre-operative isolation on postoperative pulmonary complications after elective surgery during the global SARS-CoV-2 pandemic. We performed an international prospective cohort study including patients undergoing elective surgery in October 2020. Isolation was defined as the period before surgery during which patients did not leave their house or receive visitors from outside their household. The primary outcome was postoperative pulmonary complications, adjusted in multivariable models for measured confounders. Pre-defined sub-group analyses were performed for the primary outcome. A total of 96,454 patients from 114 countries were included and overall, 26,948 (27.9%) patients isolated before surgery. Postoperative pulmonary complications were recorded in 1947 (2.0%) patients of which 227 (11.7%) were associated with SARS-CoV-2 infection. Patients who isolated pre-operatively were older, had more respiratory comorbidities and were more commonly from areas of high SARS-CoV-2 incidence and high-income countries. Although the overall rates of postoperative pulmonary complications were similar in those that isolated and those that did not (2.1% vs 2.0%, respectively), isolation was associated with higher rates of postoperative pulmonary complications after adjustment (adjusted OR 1.20, 95%CI 1.05-1.36, p = 0.005). Sensitivity analyses revealed no further differences when patients were categorised by: pre-operative testing; use of COVID-19-free pathways; or community SARS-CoV-2 prevalence. The rate of postoperative pulmonary complications increased with periods of isolation longer than 3 days, with an OR (95%CI) at 4-7 days or ≥ 8 days of 1.25 (1.04-1.48), p = 0.015 and 1.31 (1.11-1.55), p = 0.001, respectively. Isolation before elective surgery might be associated with a small but clinically important increased risk of postoperative pulmonary complications. Longer periods of isolation showed no reduction in the risk of postoperative pulmonary complications. These findings have significant implications for global provision of elective surgical care

    Corrigendum to "Search for flavour-changing neutral-current couplings between the top quark and the photon with the ATLAS detector at √s=13 TeV" (Physics Letters B, 842 (2023), 137379)

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    Search for dark matter produced in association with a single top quark and an energetic W boson in √s=13 TeV pp collisions with the ATLAS detector

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    This paper presents a search for dark matter, χ, using events with a single top quark and an energetic W boson. The analysis is based on proton–proton collision data collected with the ATLAS experiment at √s = 13 TeV during LHC Run 2 (2015–2018), corresponding to an integrated luminosity of 139 fb−1. The search considers final states with zero or one charged lepton (electron or muon), at least one b-jet and large missing transverse momentum. In addition, a result from a previous search considering two-charged-lepton final states is included in the interpretation of the results. The data are found to be in good agreement with the Standard Model predictions and the results are interpreted in terms of 95% confidence-level exclusion limits in the context of a class of dark matter models involving an extended twoHiggs-doublet sector together with a pseudoscalar mediator particle. The search is particularly sensitive to on-shell production of the charged Higgs boson state, H±, arising from the two-Higgs-doublet mixing, and its semi-invisible decays via the mediator particle, a: H± → W±a(→ χχ). Signal models with H± masses up to 1.5 TeV and a masses up to 350 GeV are excluded assuming a tan β value of 1. For masses of a of 150 (250) GeV, tan β values up to 2 are excluded for H± masses between 200 (400) GeV and 1.5 TeV. Signals with tan β values between 20 and 30 are excluded for H± masses between 500 and 800 GeV

    First proton-proton collisions at the LHC as observed with the ALICE detector: measurement of the charged-particle pseudorapidity density at root s=900 GeV

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    On 23rd November 2009, during the early commissioning of the CERN Large Hadron Collider (LHC), two counter-rotating proton bunches were circulated for the first time concurrently in the machine, at the LHC injection energy of 450 GeV per beam. Although the proton intensity was very low, with only one pilot bunch per beam, and no systematic attempt was made to optimize the collision optics, all LHC experiments reported a number of collision candidates. In the ALICE experiment, the collision region was centred very well in both the longitudinal and transverse directions and 284 events were recorded in coincidence with the two passing proton bunches. The events were immediately reconstructed and analyzed both online and offline. We have used these events to measure the pseudorapidity density of charged primary particles in the central region. In the range vertical bar eta vertical bar S collider. They also illustrate the excellent functioning and rapid progress of the LHC accelerator, and of both the hardware and software of the ALICE experiment, in this early start-up phase

    Efficacy of Lenalidomide in Different Clinical Settings in Patients with Relapsed or Progressive Multiple Myeloma: Updated Analysis of 111 Cases of the Spanish Compassionate Use Program

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    Abstract Aim: To evaluate the efficacy of Lenalidomide (Len) as compassionate use in relapsed or progressive Multiple Myeloma (MM) up to its approval in Spain. Patients and Methods: GEM-PETHEMA designed a transverse and retrospective, multicenter analysis of MM cases which Len compassionate use was requested until December, 2007. The decision to treat these patients was previous and independent from the decision to conduct the present analysis and depended only on the clinical criteria of the responsible doctors. At least, one response assessment was a must for efficacy analysis. Results: 111 MM patients have been included. Eligible patients for efficacy were 103. Mean age was 65.7 (38–85); 53 m, 50 f. Previous median lines of therapy were 3 (1–8): 92 (89.3%) have received bortezomib; 37 (35.9%) autologous PBSCT and 26 (25.2%) thalidomide. Extramedullary plasmocitomas were present in 25 (24.3%). Mean Len dose was 22.8 mg (± 4.9): 82 (79.6%) received the standard dose and schedule (25 mg d for 3 w every 4 w) and 21 (20.4%) received less dose and/or different schedule. 92 (89.3%) received Dexametasone (mean dose 58.33 mg/w) [± 35.8]). Response: 4 (3.9%) sCR, 11 CR (10.7%), 12 VGPR (11.7%), 41 PR (39.8%), 20 SD (19.4%), 13 PD (12.6%), 2 NE (1.9). Among groups, response equal or superior to PR was observed in all settings: 64.1% in prior exposed to bortezomib, 46.1% in prior exposed to thalidomide and 40.0% in patients with extramedullary plasmocitomas. Previous transplant, the number of previous lines received, renal failure, age, or cytogenetic did not affect significantly the overall response rate. Median duration of treatment was 7.7 m (1–21); median TTP was 8.3 m and median global survival since starting Len therapy was 11 m (6–22). Median survival since diagnostic was 49 m (40–60). At the time of analysis, 46 (45.5%) patients were still on Len therapy, and 72 (79.6%) were alive. Toxicity: ≥ grade II: neutropenia, 51 (46.4%); thrombocytopenia, 39 (35.5%); DVT, 5 (4.5%); rash, 3 (2.7%); neutropenic fever, 8 (7.3%); others, 13 (11.8%). DVT/PE prophylaxis was used in 89 (86.4%) patients: LWMH in 43.8 % and low dose aspirin in 48.3 %. No PE was reported. Conclusions: Lenalidomide is effective in this heavily pre-treated MM population-progressive or refractory to standard therapy-even in different clinical settings. The most frequent association to Len was intermediate dose of Dex. Although response rate was superior in patients exposed previously to bortezomib, no differences on duration and survival were observed. Patients with extramedullary plasmocitomas showed also response. Toxicity, mainly myelosupression was predictable and manageable with dose adjustments and cytokine support.</jats:p

    Discovery of X-Ray Polarization from the Black Hole Transient Swift J1727.8-1613

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    We report the first detection of the X-ray polarization of the bright transient Swift J1727.8-1613 with the Imaging X-ray Polarimetry Explorer. The observation was performed at the beginning of the 2023 discovery outburst, when the source resided in the bright hard state. We find a time- and energy-averaged polarization degree of 4.1% +/- 0.2% and a polarization angle of 2.degrees 2 +/- 1.degrees 3 (errors at 68% confidence level; this translates to similar to 20 sigma significance of the polarization detection). This finding suggests that the hot corona emitting the bulk of the detected X-rays is elongated, rather than spherical. The X-ray polarization angle is consistent with that found in submillimeter wavelengths. Since the submillimeter polarization was found to be aligned with the jet direction in other X-ray binaries, this indicates that the corona is elongated orthogonal to the jet

    The First X-Ray Polarization Observation of the Black Hole X-Ray Binary 4U 1630-47 in the Steep Power-law State

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    The Imaging X-ray Polarimetry Explorer (IXPE) observed the black hole X-ray binary 4U 1630-47 in the steep power-law (or very high) state. The observations reveal a linear polarization degree of the 2-8 keV X-rays of 6.8% +/- 0.2% at a position angle of 21.degrees 3 +/- 0.degrees 9 east of north (all errors at 1 sigma confidence level). Whereas the polarization degree increases with energy, the polarization angle stays constant within the accuracy of our measurements. We compare the polarization of the source in the steep power-law state with the previous IXPE measurement of the source in the high soft state. We find that, even though the source flux and spectral shape are significantly different between the high soft state and the steep power-law state, their polarization signatures are similar. Assuming that the polarization of both the thermal and power-law emission components are constant over time, we estimate the power-law component polarization to be 6.8%-7.0% and note that the polarization angle of the thermal and power-law components must be approximately aligned. We discuss the implications for the origin of the power-law component and the properties of the emitting plasma

    Identification of common variants influencing risk of the tauopathy progressive supranuclear palsy [Letter]

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    Progressive supranuclear palsy (PSP) is a movement disorder with prominent tau neuropathology. Brain diseases with abnormal tau deposits are called tauopathies, the most common of which is Alzheimer's disease. Environmental causes of tauopathies include repetitive head trauma associated with some sports. To identify common genetic variation contributing to risk for tauopathies, we carried out a genome-wide association study of 1,114 individuals with PSP (cases) and 3,247 controls (stage 1) followed by a second stage in which we genotyped 1,051 cases and 3,560 controls for the stage 1 SNPs that yielded P ≤ 10−3. We found significant previously unidentified signals (P < 5 × 10−8) associated with PSP risk at STX6, EIF2AK3 and MOBP. We confirmed two independent variants in MAPT affecting risk for PSP, one of which influences MAPT brain expression. The genes implicated encode proteins for vesicle-membrane fusion at the Golgi-endosomal interface, for the endoplasmic reticulum unfolded protein response and for a myelin structural component

    Timing of Cholecystectomy After Moderate and Severe Acute Biliary Pancreatitis

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    IMPORTANCE Considering the lack of equipoise regarding the timing of cholecystectomy in patients with moderately severe and severe acute biliary pancreatitis (ABP), it is critical to assess this issue.OBJECTIVE To assess the outcomes of early cholecystectomy (EC) in patients with moderately severe and severe ABP.DESIGN, SETTINGS, AND PARTICIPANTS This cohort study retrospectively analyzed real-life data from the MANCTRA-1 (Compliance With Evidence-Based Clinical Guidelines in the Management of Acute Biliary Pancreatitis) data set, assessing 5304 consecutive patients hospitalized between January 1, 2019, and December 31, 2020, for ABP from 42 countries. A total of 3696 patients who were hospitalized for ABP and underwent cholecystectomy were included in the analysis; of these, 1202 underwent EC, defined as a cholecystectomy performed within 14 days of admission. Univariable and multivariable logistic regression models were used to identify prognostic factors of mortality and morbidity. Data analysis was performed from January to February 2023.MAIN OUTCOMES Mortality and morbidity after EC.RESULTS Of the 3696 patients (mean [SD] age, 58.5 [17.8] years; 1907 [51.5%] female) included in the analysis, 1202 (32.5%) underwent EC and 2494 (67.5%) underwent delayed cholecystectomy (DC). Overall, EC presented an increased risk of postoperative mortality (1.4% vs 0.1%, P &lt;.001) and morbidity (7.7% vs 3.7%, P &lt; .001) compared with DC. On the multivariable analysis, moderately severe and severe ABP were associated with increased mortality (odds ratio [OR], 361.46; 95% CI, 2.28-57 212.31; P = .02) and morbidity (OR, 2.64; 95% CI, 1.35-5.19; P = .005). In patients with moderately severe and severe ABP (n = 108), EC was associated with an increased risk of mortality (16 [15.6%] vs 0 [0%], P &lt; .001), morbidity (30 [30.3%] vs 57 [5.5%], P &lt; .001), bile leakage (2 [2.4%] vs 4 [0.4%], P = .02), and infections (12 [14.6%] vs 4 [0.4%], P &lt; .001) compared with patients with mild ABP who underwent EC. In patients with moderately severe and severe ABP (n = 108), EC was associated with higher mortality (16 [15.6%] vs 2 [1.2%], P &lt; .001), morbidity (30 [30.3%] vs 17 [10.3%], P &lt; .001), and infections (12 [14.6%] vs 2 [1.3%], P &lt; .001) compared with patients with moderately severe and severe ABP who underwent DC. On the multivariable analysis, the patient's age (OR, 1.12; 95% CI, 1.02-1.36; P = .03) and American Society of Anesthesiologists score (OR, 5.91; 95% CI, 1.06-32.78; P = .04) were associated with mortality; severe complications of ABP were associated with increased mortality (OR, 50.04; 95% CI, 2.37-1058.01; P = .01) and morbidity (OR, 33.64; 95% CI, 3.19-354.73; P = .003).CONCLUSIONS AND RELEVANCE This cohort study's findings suggest that EC should be considered carefully in patients with moderately severe and severe ABP, as it was associated with increased postoperative mortality and morbidity. However, older and more fragile patients manifesting severe complications related to ABP should most likely not be considered for EC
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