1,586 research outputs found
Measurement of the cross-section and charge asymmetry of bosons produced in proton-proton collisions at TeV with the ATLAS detector
This paper presents measurements of the and cross-sections and the associated charge asymmetry as a
function of the absolute pseudorapidity of the decay muon. The data were
collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with
the ATLAS experiment at the LHC and correspond to a total integrated luminosity
of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements
varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the
1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured
with an uncertainty between 0.002 and 0.003. The results are compared with
predictions based on next-to-next-to-leading-order calculations with various
parton distribution functions and have the sensitivity to discriminate between
them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables,
submitted to EPJC. All figures including auxiliary figures are available at
https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13
Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector
A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13 TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139 fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV
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
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
A joint SZ-X-ray-optical analysis of the dynamical state of 288 massive galaxy clusters
We use imaging from the first three years of the Dark Energy Survey to
characterize the dynamical state of 288 galaxy clusters at detected in the South Pole Telescope (SPT) Sunyaev-Zeldovich (SZ)
effect survey (SPT-SZ). We examine spatial offsets between the position of the
brightest cluster galaxy (BCG) and the center of the gas distribution as traced
by the SPT-SZ centroid and by the X-ray centroid/peak position from Chandra and
XMM data. We show that the radial distribution of offsets provides no evidence
that SPT SZ-selected cluster samples include a higher fraction of mergers than
X-ray-selected cluster samples. We use the offsets to classify the dynamical
state of the clusters, selecting the 43 most disturbed clusters, with half of
those at , a region seldom explored previously. We find that
Schechter function fits to the galaxy population in disturbed clusters and
relaxed clusters differ at but not at lower redshifts. Disturbed
clusters at have steeper faint-end slopes and brighter characteristic
magnitudes. Within the same redshift range, we find that the BCGs in relaxed
clusters tend to be brighter than the BCGs in disturbed samples, while in
agreement in the lower redshift bin. Possible explanations includes a higher
merger rate, and a more efficient dynamical friction at high redshift. The
red-sequence population is less affected by the cluster dynamical state than
the general galaxy population.Comment: 21 pages, 12 Figures, 4 Tables. Accepted for publication in MNRA
Impact of chronic obstructive pulmonary disease on short-term outcome in patients with ST-elevation myocardial infarction during COVID-19 pandemic: insights from the international multicenter ISACS-STEMI registry
Background: Chronic obstructive pulmonary disease (COPD) is projected to become the third cause of mortality worldwide. COPD shares several pathophysiological mechanisms with cardiovascular disease, especially atherosclerosis. However, no definite answers are available on the prognostic role of COPD in the setting of ST elevation myocardial infarction (STEMI), especially during COVID-19 pandemic, among patients undergoing primary angioplasty, that is therefore the aim of the current study. Methods: In the ISACS-STEMI COVID-19 registry we included retrospectively patients with STEMI treated with primary percutaneous coronary intervention (PCI) between March and June of 2019 and 2020 from 109 high-volume primary PCI centers in 4 continents. Results: A total of 15,686 patients were included in this analysis. Of them, 810 (5.2%) subjects had a COPD diagnosis. They were more often elderly and with a more pronounced cardiovascular risk profile. No preminent procedural dissimilarities were noticed except for a lower proportion of dual antiplatelet therapy at discharge among COPD patients (98.9% vs. 98.1%, P = 0.038). With regards to short-term fatal outcomes, both in-hospital and 30-days mortality occurred more frequently among COPD patients, similarly in pre-COVID-19 and COVID-19 era. However, after adjustment for main baseline differences, COPD did not result as independent predictor for in-hospital death (adjusted OR [95% CI] = 0.913[0.658–1.266], P = 0.585) nor for 30-days mortality (adjusted OR [95% CI] = 0.850 [0.620–1.164], P = 0.310). No significant differences were detected in terms of SARS-CoV-2 positivity between the two groups. Conclusion: This is one of the largest studies investigating characteristics and outcome of COPD patients with STEMI undergoing primary angioplasty, especially during COVID pandemic. COPD was associated with significantly higher rates of in-hospital and 30-days mortality. However, this association disappeared after adjustment for baseline characteristics. Furthermore, COPD did not significantly affect SARS-CoV-2 positivity. Trial registration number: NCT 04412655 (2nd June 2020)
Age-Related Effects of COVID-19 Pandemic on Mechanical Reperfusion and 30-Day Mortality for STEMI: Results of the ISACS-STEMI COVID-19 Registry
Background: The constraints in the management of patients with ST-segment elevation myocardial infarction (STEMI) during the COVID-19 pandemic have been suggested to have severely impacted mortality levels. The aim of the current analysis is to evaluate the age-related effects of the COVID-19 pandemic on mechanical reperfusion and 30-day mortality for STEMI within the registry ISACS-STEMI COVID-19. Methods: This retrospective multicenter registry was performed in high-volume PPCI centers on four continents and included STEMI patients undergoing PPCI in March-June 2019 and 2020. Patients were divided according to age (= 75 years). The main outcomes were the incidence and timing of PPCI, (ischemia time longer than 12 h and door-to-balloon longer than 30 min), and in-hospital or 30-day mortality. Results: We included 16,683 patients undergoing PPCI in 109 centers. In 2020, during the pandemic, there was a significant reduction in PPCI as compared to 2019 (IRR 0.843 (95%-CI: 0.825-0.861, p < 0.0001). We found a significant age-related reduction (7%, p = 0.015), with a larger effect on elderly than on younger patients. Furthermore, we observed significantly higher 30-day mortality during the pandemic period, especially among the elderly (13.6% vs. 17.9%, adjusted HR (95% CI) = 1.55 [1.24-1.93], p < 0.001) as compared to younger patients (4.8% vs. 5.7%; adjusted HR (95% CI) = 1.25 [1.05-1.49], p = 0.013), as a potential consequence of the significantly longer ischemia time observed during the pandemic. Conclusions: The COVID-19 pandemic had a significant impact on the treatment of patients with STEMI, with a 16% reduction in PPCI procedures, with a larger reduction and a longer delay to treatment among elderly patients, which may have contributed to increase in-hospital and 30-day mortality during the pandemic
Age-Related Effects of COVID-19 Pandemic on Mechanical Reperfusion and 30-Day Mortality for STEMI : Results of the ISACS-STEMI COVID-19 Registry
Background: The constraints in the management of patients with ST-segment elevation
myocardial infarction (STEMI) during the COVID-19 pandemic have been suggested to have severely
impacted mortality levels. The aim of the current analysis is to evaluate the age-related effects of
the COVID-19 pandemic on mechanical reperfusion and 30-day mortality for STEMI within the
registry ISACS-STEMI COVID-19. Methods: This retrospective multicenter registry was performed
in high-volume PPCI centers on four continents and included STEMI patients undergoing PPCI
in March–June 2019 and 2020. Patients were divided according to age (< or ≥75 years). The main
outcomes were the incidence and timing of PPCI, (ischemia time longer than 12 h and door-to-balloon
longer than 30 min), and in-hospital or 30-day mortality. Results: We included 16,683 patients
undergoing PPCI in 109 centers. In 2020, during the pandemic, there was a significant reduction in
PPCI as compared to 2019 (IRR 0.843 (95%-CI: 0.825–0.861, p < 0.0001). We found a significant agerelated reduction (7%, p = 0.015), with a larger effect on elderly than on younger patients. Furthermore,
we observed significantly higher 30-day mortality during the pandemic period, especially among the
elderly (13.6% vs. 17.9%, adjusted HR (95% CI) = 1.55 [1.24–1.93], p < 0.001) as compared to younger
patients (4.8% vs. 5.7%; adjusted HR (95% CI) = 1.25 [1.05–1.49], p = 0.013), as a potential consequence
of the significantly longer ischemia time observed during the pandemic. Conclusions: The COVID-19
pandemic had a significant impact on the treatment of patients with STEMI, with a 16% reduction in
PPCI procedures, with a larger reduction and a longer delay to treatment among elderly patients,
which may have contributed to increase in-hospital and 30-day mortality during the pandemic
Gender Difference in the Effects of COVID-19 Pandemic on Mechanical Reperfusion and 30-Day Mortality for STEMI: Results of the ISACS-STEMI COVID-19 Registry
Background. Several reports have demonstrated the impact of the COVID-19 pandemic on
the management and outcome of patients with ST-segment elevation myocardial infarction (STEMI).
The aim of the current analysis is to investigate the potential gender difference in the effects of the
COVID-19 pandemic on mechanical reperfusion and 30-day mortality for STEMI patients within the
ISACS-STEMI COVID-19 Registry. Methods. This retrospective multicenter registry was performed
in high-volume primary percutaneous coronary intervention (PPCI) centers on four continents and
included STEMI patients undergoing PPCIs in March–June 2019 and 2020. Patients were divided
according to gender. The main outcomes were the incidence and timing of the PPCI, (ischemia time
≥ 12 h and door-to-balloon ≥ 30 min) and in-hospital or 30-day mortality. Results. We included
16683 STEMI patients undergoing PPCIs in 109 centers. In 2020 during the pandemic, there was a
significant reduction in PPCIs compared to 2019 (IRR 0.843 (95% CI: 0.825–0.861, p < 0.0001). We did
not find a significant gender difference in the effects of the COVID-19 pandemic on the numbers of
STEMI patients, which were similarly reduced from 2019 to 2020 in both groups, or in the mortality
rates. Compared to prepandemia, 30-day mortality was significantly higher during the pandemic
period among female (12.1% vs. 8.7%; adjusted HR [95% CI] = 1.66 [1.31–2.11], p < 0.001) but not
male patients (5.8% vs. 6.7%; adjusted HR [95% CI] = 1.14 [0.96–1.34], p = 0.12). Conclusions. The
COVID-19 pandemic had a significant impact on the treatment of patients with STEMI, with a
16% reduction in PPCI procedures similarly observed in both genders. Furthermore, we observed
significantly increased in-hospital and 30-day mortality rates during the pandemic only among
females. Trial registration number: NCT 04412655
Impact of chronic obstructive pulmonary disease on short-term outcome in patients with ST-elevation myocardial infarction during COVID-19 pandemic: insights from the international multicenter ISACS-STEMI registry
Background Chronic obstructive pulmonary disease (COPD) is projected to become the third cause of mortality worldwide. COPD shares several pathophysiological mechanisms with cardiovascular disease, especially atherosclerosis. However, no definite answers are available on the prognostic role of COPD in the setting of ST elevation myocardial infarction (STEMI), especially during COVID-19 pandemic, among patients undergoing primary angioplasty, that is therefore the aim of the current study. Methods In the ISACS-STEMI COVID-19 registry we included retrospectively patients with STEMI treated with primary percutaneous coronary intervention (PCI) between March and June of 2019 and 2020 from 109 high-volume primary PCI centers in 4 continents. Results A total of 15,686 patients were included in this analysis. Of them, 810 (5.2%) subjects had a COPD diagnosis. They were more often elderly and with a more pronounced cardiovascular risk profile. No preminent procedural dissimilarities were noticed except for a lower proportion of dual antiplatelet therapy at discharge among COPD patients (98.9% vs. 98.1%, P = 0.038). With regards to short-term fatal outcomes, both in-hospital and 30-days mortality occurred more frequently among COPD patients, similarly in pre-COVID-19 and COVID-19 era. However, after adjustment for main baseline differences, COPD did not result as independent predictor for in-hospital death (adjusted OR [95% CI] = 0.913[0.658-1.266], P = 0.585) nor for 30-days mortality (adjusted OR [95% CI] = 0.850 [0.620-1.164], P = 0.310). No significant differences were detected in terms of SARS-CoV-2 positivity between the two groups. Conclusion This is one of the largest studies investigating characteristics and outcome of COPD patients with STEMI undergoing primary angioplasty, especially during COVID pandemic. COPD was associated with significantly higher rates of in-hospital and 30-days mortality. However, this association disappeared after adjustment for baseline characteristics. Furthermore, COPD did not significantly affect SARS-CoV-2 positivity. Trial registration number: NCT 04412655 (2nd June 2020)
Impact of Smoking Status on Mortality in STEMI Patients Undergoing Mechanical Reperfusion for STEMI : Insights from the ISACS–STEMI COVID-19 Registry
The so-called “smoking paradox”, conditioning lower mortality in smokers among STEMI
patients, has seldom been addressed in the settings of modern primary PCI protocols. The ISACS–
STEMI COVID-19 is a large-scale retrospective multicenter registry addressing in-hospital mortality,
reperfusion, and 30-day mortality among primary PCI patients in the era of the COVID-19 pandemic.
Among the 16,083 STEMI patients, 6819 (42.3%) patients were active smokers, 2099 (13.1%) previous smokers, and 7165 (44.6%) non-smokers. Despite the impaired preprocedural recanalization
(p < 0.001), active smokers had a significantly better postprocedural TIMI flow compared with nonsmokers (p < 0.001); this was confirmed after adjustment for all baseline and procedural confounders,
and the propensity score. Active smokers had a significantly lower in-hospital (p < 0.001) and 30-day
(p < 0.001) mortality compared with non-smokers and previous smokers; this was confirmed after
adjustment for all baseline and procedural confounders, and the propensity score. In conclusion, in
our population, active smoking was significantly associated with improved epicardial recanalization
and lower in-hospital and 30-day mortality compared with previous and non-smoking histor
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