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- G., Aad, et al.
(författare)
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Measurement of the tt¯ production cross-section and lepton differential distributions in eμ dilepton events from pp collisions at √s=13TeV with the ATLAS detector
- 2020
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Ingår i: European Physical Journal C. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 80:6
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Tidskriftsartikel (refereegranskat)abstract
- The inclusive top quark pair (tt¯) production cross-section σtt¯ has been measured in proton–proton collisions at s=13TeV, using 36.1 fb- 1 of data collected in 2015–2016 by the ATLAS experiment at the LHC. Using events with an opposite-charge eμ pair and b-tagged jets, the cross-section is measured to be: σtt¯=826.4±3.6(stat)±11.5(syst)±15.7(lumi)±1.9(beam)pb,where the uncertainties reflect the limited size of the data sample, experimental and theoretical systematic effects, the integrated luminosity, and the LHC beam energy, giving a total uncertainty of 2.4%. The result is consistent with theoretical QCD calculations at next-to-next-to-leading order. It is used to determine the top quark pole mass via the dependence of the predicted cross-section on mtpole, giving mtpole=173.1-2.1+2.0GeV. It is also combined with measurements at s=7TeV and s=8TeV to derive ratios and double ratios of tt¯ and Z cross-sections at different energies. The same event sample is used to measure absolute and normalised differential cross-sections as functions of single-lepton and dilepton kinematic variables, and the results are compared with predictions from various Monte Carlo event generators. © 2020, CERN for the benefit of the ATLAS collaboration.
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| 3. |
- Mullier, G.A., et al.
(författare)
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Measurements of jet observables sensitive to b -quark fragmentation in t t ¯ events at the LHC with the ATLAS detector
- 2022
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Ingår i: Physical Review D. - : American Physical Society (APS). - 2470-0010 .- 2470-0029. ; 106:3
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Tidskriftsartikel (refereegranskat)abstract
- Several observables sensitive to the fragmentation of b quarks into b hadrons are measured using 36 fb-1 of s=13 TeV proton-proton collision data collected with the ATLAS detector at the LHC. Jets containing b hadrons are obtained from a sample of dileptonic tt¯ events, and the associated set of charged-particle tracks is separated into those from the primary pp interaction vertex and those from the displaced b-decay secondary vertex. This division is used to construct observables that characterize the longitudinal and transverse momentum distributions of the b hadron within the jet. The measurements have been corrected for detector effects and provide a test of heavy-quark-fragmentation modeling at the LHC in a system where the top-quark decay products are color connected to the proton beam remnants. The unfolded distributions are compared with the predictions of several modern Monte Carlo parton-shower generators and generator tunes, and a wide range of agreement with the data is observed, with p values varying from 5×10-4 to 0.98. These measurements complement similar measurements from e+e- collider experiments in which the b quarks originate from a color singlet Z/γ∗. © 2022 CERN.
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| 5. |
- Albert, Christian, et al.
(författare)
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Neutrophil Gelatinase-Associated Lipocalin Measured on Clinical Laboratory Platforms for the Prediction of Acute Kidney Injury and the Associated Need for Dialysis Therapy : A Systematic Review and Meta-analysis
- 2020
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Ingår i: American Journal of Kidney Diseases. - : Elsevier BV. - 0272-6386 .- 1523-6838. ; 76:6, s. 826-
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Forskningsöversikt (refereegranskat)abstract
- Rationale & Objective: The usefulness of measures of neutrophil gelatinase-associated lipocalin (NGAL) in urine or plasma obtained on clinical laboratory platforms for predicting acute kidney injury (AKI) and AKI requiring dialysis (AKI-D) has not been fully evaluated. We sought to quantitatively summarize published data to evaluate the value of urinary and plasma NGAL for kidney risk prediction.Study Design: Literature-based meta-analysis and individual-study-data meta-analysis of diagnostic studies following PRISMA-IPD guidelines.Setting & Study Populations: Studies of adults investigating AKI, severe AKI, and AKI-D in the setting of cardiac surgery, intensive care, or emergency department care using either urinary or plasma NGAL measured on clinical laboratory platforms.Selection Criteria for Studies: PubMed, Web of Science, Cochrane Library, Scopus, and congress abstracts ever published through February 2020 reporting diagnostic test studies of NGAL measured on clinical laboratory platforms to predict AKI.Data Extraction: Individual-study-data meta analysis was accomplished by giving authors data specifications tailored to their studies and requesting standardized patient-level data analysis.Analytical Approach: Individual-study-data meta analysis used a bivariate time-to-event model for interval-censored data from which discriminative ability (AUC) was characterized. NGAL cutoff concentrations at 95% sensitivity, 95% specificity, and optimal sensitivity and specificity were also estimated. Models incorporated as confounders the clinical setting and use versus nonuse of urine output as a criterion for AKI. A literature-based meta-analysis was also performed for all published studies including those for which the authors were unable to provide individual-study data analyses.Results: We included 52 observational studies involving 13,040 patients. We analyzed 30 data sets for the individual-study-data meta-analysis. For AKI, severe AKI, and AKI-D, numbers of events were 837, 304, and 103 for analyses of urinary NGAL, respectively; these values were 705, 271, and 178 for analyses of plasma NGAL. Discriminative performance was similar in both meta-analyses. Individual-study-data meta-analysis AUCs for urinary NGAL were 0.75 (95% CI, 0.73-0.76) and 0.80 (95% CI, 0.79-0.81) for severe AKI and AKI-D, respectively; for plasma NGAL, the corresponding AUCs were 0.80 (95% CI, 0.790.81) and 0.86 (95% CI, 0.84-0.8 6). Cutoff concentrations at 95% specificity for urinary NGAL were >580 ng/mL with 27% sensitivity for severe AKI and >589 ng/mL with 24% sensitivity for AKI-D. Corresponding cutoffs for plasma NGAL were >364 ng/mL with 44% sensitivity and >546 ng/mL with 26% sensitivity, respectively.Limitations: Practice variability in initiation of dialysis. Imperfect harmonization of data across studies. Conclusions: Urinary and plasma NGAL concentrations may identify patients at high risk for AKI in clinical research and practice. The cutoff concentrations reported in this study require prospective evaluation.
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| 6. |
- Balintescu, A., et al.
(författare)
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Glycaemic control and sepsis risk in adults with type 1 diabetes
- 2023
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Ingår i: Diabetes Obesity & Metabolism. - : Wiley. - 1462-8902 .- 1463-1326. ; 25:7, s. 1942-1949
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Tidskriftsartikel (refereegranskat)abstract
- Aims: To study the association between glycated haemoglobin (HbA1c) and sepsis in adults with type 1 diabetes, and to explore the relationship between HbA1c and mortality among individuals who developed sepsis.Materials and Methods: We included 33 549 adult individuals with type 1 diabetes recorded in the Swedish National Diabetes Register between January 2005 and December 2015. We used multivariable Cox regression and restricted cubic spline analyses to study the relationship between HbA1c values and sepsis occurrence and association between HbA1c and mortality among those with sepsis.Results: In total, 713 (2.1%) individuals developed sepsis during the study period. Com-pared with the HbA1c reference interval of 48-52 mmol/mol (6.5-6.9%), the adjusted hazard ratio for sepsis was: 2.50 [95% confidence interval (CI) 1.18-5.29] for HbA1c <43 mmol/mol; 1.88 (95% CI 0.96-3.67) for HbA1c 43-47 mmol/mol; 1.78 (95% CI 1.09-2.89) for HbA1c 53-62 mmol/mol; 1.86 (95% CI 1.14-3.03) for HbA1c 63-72 mmol/mol; 3.15 (95% CI 1.91-5.19) for HbA1c 73-82 mmol/mol; and 4.26 (95% CI 2.53-7.16) for HbA1c >82 mmol/mol. On multivariable restricted cubic spline analy-sis, we found a J-shaped association between HbA1c and sepsis risk, with the lowest risk observed at HbA1c of approximately 53 mmol/mol. We found no association between HbA1c and mortality among those individuals who developed sepsis.Conclusions: In our nationwide observational study of adult individuals with type 1 diabetes we found a J-shaped relationship between HbA1c and risk of sepsis, with the lowest risk at HbA1c levels about 53 mmol/mol (7.0%). HbA1c was not associ-ated with mortality in individuals affected by sepsis.
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| 8. |
- Holmqvist, Jacob, et al.
(författare)
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Patterns and determinants of blood transfusion in intensive care in Sweden between 2010 and 2018: A nationwide, retrospective cohort study
- 2022
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Ingår i: Transfusion. - : Wiley. - 0041-1132 .- 1537-2995. ; 62:6, s. 1188-1198
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Tidskriftsartikel (refereegranskat)abstract
- Background Intensive care unit (ICU) patients are transfused with blood products for a number of reasons, from massive ongoing hemorrhage, to mild anemia following blood sampling, combined with bone marrow depression due to critical illness. There's a paucity of data on transfusions in ICUs and most studies are based on audits or surveys. The aim of this study was to provide a complete picture of ICU-related transfusions in Sweden. Methods We conducted a register based retrospective cohort study with data on all adult patient admissions from 82 of 84 Swedish ICUs between 2010 and 2018, as recorded in the Swedish Intensive Care Register. Transfusions were obtained from the SCANDAT-3 database. Descriptive statistics were computed, characterizing transfused and nontransfused patients. The distribution of blood use comparing different ICUs was investigated by computing the observed proportion of ICU stays with a transfusion, as well as the expected proportion. Results In 330,938 ICU episodes analyzed, at least one transfusion was administered for 106,062 (32%). For both red-cell units and plasma, the fraction of patients who were transfused decreased during the study period from 31.3% in 2010 to 24.6% in 2018 for red-cells, and from 16.6% in 2010 to 9.4% in 2018 for plasma. After adjusting for a range of factors, substantial variation in transfusion frequency remained, especially for plasma units. Conclusion Despite continuous decreases in utilization, transfusions remain common among Swedish ICU patients. There is considerable unexplained variation in transfusion rates. More research is needed to establish stronger critiera for when to transfuse ICU patients.
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