Search for standard model production of four top quarks in the lepton + jets channel in pp collisions at √s = 8 TeV

Open Access, Copyright CERN, for the benefit of the CMS Collaboration. Article funded by SCOAP3.Abstract: A search is presented for standard model (SM) production of four top quarks (Formula presented.) in pp collisions in the lepton + jets channel. The data correspond to an integrated luminosity of 19.6 fb−1 recorded at a centre-of-mass energy of 8 TeV with the CMS detector at the CERN LHC. The expected cross section for SM (Formula presented.) production is (Formula presented.). A combination of kinematic reconstruction and multivariate techniques is used to distinguish between the small signal and large background. The data are consistent with expectations of the SM, and an upper limit of 32 fb is set at a 95% confidence level on the cross section for producing four top quarks in the SM, where a limit of 32 ± 17 fb is expected

Epidemiology, prognostic factors, and outcome of trauma patients admitted in a Brazilian intensive care unit

Gabriella F Pogorzelski,1 Taline AAL Silva,1 Thamara Piazza,1 Tomás M Lacerda,1 Fernando AC Spencer Netto,2,3 Amaury Cesar Jorge,4 Péricles AD Duarte4 1College of Medicine, Western Parana State University, Cascavel, PR, Brazil; 2Department of Surgery, Western Parana State University Hospital, Cascavel, PR, Brazil; 3Department of Emergency Medicine, Western Parana State University Hospital, Cascavel, PR, Brazil; 4General ICU, Western Parana State University Hospital, Cascavel, PR, Brazil Background: Trauma is a major cause of hospital admissions and is associated with manifold complications and high mortality rates. However, data on intensive care unit (ICU) admissions are scarce in developing and low-income countries, where its incidence has been increasing. Objectives: To analyze epidemiological and clinical factors and outcomes in adult trauma patients admitted to the ICU of a public teaching hospital in a developing country as well as to identify risk factors for complications in the ICU. Patients and methods: Retrospective cohort of adult trauma patients admitted to the general ICU of a public teaching hospital in southern Brazil in the year 2012. Demographic, clinical, and outcome data from the ICU were analyzed. Results: During the study period, 144 trauma patients were admitted (83% male, Acute Physiology and Chronic Health Evaluation Score II =18.6±7.2, age =33.3 years, 93% required mechanical ventilation). Of these, 60.4% suffered a traffic accident (52% motorcycle), and 31.2% were victims of violence (aggressions, gunshot wounds, or stabbing); 71% had brain trauma, 37% had chest trauma, and 21% had abdominal trauma. Patients with trauma presented a high incidence of complications, such as infections, acute renal failure, acute respiratory distress syndrome, and thrombocytopenia. The ICU mortality rate was 22.9%. Conclusion: In a Brazilian public teaching ICU, there was a great variability of trauma etiologies (mainly traffic accidents with motorcycles and victims of violence); patients with trauma had a high incidence of complications and mortality in the ICU. Keywords: trauma, intensive care, epidemiology, mortalit

Neuraminidase inhibitors and hospital length of stay: a meta-analysis of individual participant data to determine treatment effectiveness among patients hospitalized with nonfatal 2009 pandemic iInfluenza A(H1N1) virus infection

BACKGROUND: The effect of neuraminidase inhibitor (NAI) treatment on length of stay (LoS) in patients hospitalized with influenza is unclear. METHODS: We conducted a one-stage individual participant data (IPD) meta-analysis exploring the association between NAI treatment and LoS in patients hospitalized with 2009 influenza A(H1N1) virus (A[H1N1]pdm09) infection. Using mixed-effects negative binomial regression and adjusting for the propensity to receive NAI, antibiotic, and corticosteroid treatment, we calculated incidence rate ratios (IRRs) and 95% confidence intervals (CIs). Patients with a LoS of <1 day and those who died while hospitalized were excluded. RESULTS: We analyzed data on 18 309 patients from 70 clinical centers. After adjustment, NAI treatment initiated at hospitalization was associated with a 19% reduction in the LoS among patients with clinically suspected or laboratory-confirmed influenza A(H1N1)pdm09 infection (IRR, 0.81; 95% CI, .78-.85), compared with later or no initiation of NAI treatment. Similar statistically significant associations were seen in all clinical subgroups. NAI treatment (at any time), compared with no NAI treatment, and NAI treatment initiated <2 days after symptom onset, compared with later or no initiation of NAI treatment, showed mixed patterns of association with the LoS. CONCLUSIONS: When patients hospitalized with influenza are treated with NAIs, treatment initiated on admission, regardless of time since symptom onset, is associated with a reduced LoS, compared with later or no initiation of treatment