Anisotropy in the pion angular distribution of the reaction pp -> pp pi0 at 400 MeV

The reaction pp -> pp pi0 was studied with the WASA detector at the CELSIUS storage ring. The center of mass angular distribution of the pi0 was obtained by detection of the gamma decay products together with the two outgoing protons, and found to be anisotropic with a negative second derivative slope, in agreement with the theoretical predictions from a microscopic calculation.Comment: Revtex 4 style, 5 pages 7 figures, PACS numbers:13.60.Le, 13.75.Cs, 21.45.+v, 25.10.+

Clostridium difficile infection after cardiac surgery: Prevalence, morbidity, mortality, and resource utilization

ObjectiveDespite increasing efforts to prevent infection, the prevalence of hospital-associated Clostridium difficile infections (CDI) is increasing. Heightened awareness prompted this study of the prevalence and morbidity associated with CDI after cardiac surgery.MethodsA total of 22,952 patients underwent cardiac surgery at Cleveland Clinic from January 2005 to January 2011. CDI was diagnosed by enzyme immunoassay for toxins and, more recently, polymerase chain reaction (PCR) testing. Hospital outcomes and long-term survival were compared with those of the remaining population in propensity-matched groups.ResultsOne hundred forty-five patients (0.63%) tested positive for CDI at a median of 9 days postoperatively, 135 by enzyme immunoassay and 11 by PCR. Its prevalence more than doubled over the study period. Seventy-seven patients (48%) were transfers from outside hospitals. Seventy-three patients (50%) were exposed preoperatively to antibiotics and 79 (56%) to proton-pump inhibitors. Patients with CDI had more baseline comorbidities, more reoperations, and received more blood products than patients who did not have CDI. Presenting symptoms included diarrhea (107; 75%), distended abdomen (48; 34%), and abdominal pain (27; 19%). All were treated with metronidazole or vancomycin. Sixteen patients (11%) died in hospital, including 5 of 10 who developed toxic colitis; 3 of 4 undergoing total colectomy survived. Among matched patients, those with CDI had more septicemia (P < .0001), renal failure (P = .0002), reoperations (P < .0001), prolonged postoperative ventilation (P < .0001), longer hospital stay (P < .0001), and lower 3-year survival, 52% versus 64% (P = .03), than patients who did not have CDI.ConclusionsAlthough rare, the prevalence of CDI is increasing, contributing importantly to morbidity and mortality after cardiac surgery. If toxic colitis develops, mortality is high, but colectomy may be lifesaving

Adverse events during reoperative cardiac surgery: Frequency, characterization, and rescue

ObjectivesTo (1) determine frequency of occurrence and risk factors for intraoperative adverse events (IAE) during reoperative cardiac surgery, (2) characterize them with respect to structure injured, timing, and use of preventive strategies, and (3) identify the impact on outcome in terms of successful and unsuccessful rescue and cost.MethodsOperative notes of 1847 patients undergoing reoperative cardiac surgery were reviewed to identify and characterize documented intraoperative adverse events. Logistic regression modeling was used to identify risk factors for intraoperative adverse events and outcomes. Expected versus observed poor outcomes (stroke, myocardial infarction, death) was used to measure rescue.ResultsAmong 127 patients, 145 (7%) intraoperative adverse events occurred. These included injuries to bypass grafts (n = 47), heart (n = 38), and great vessels (n = 28) and ischemia without graft injury (n = 22). Most occurred on opening (n = 34, 23%) and during prebypass dissection (n = 57, 39%). Risk incremented as reoperations increased. Seventy-seven patients experienced 1 or more lapses in preventive strategies. Patients with intraoperative adverse events had a greater number of poor outcomes (n = 24 [19%] vs n = 107 [6.2%]; P < .0001) and incurred higher direct technical intraoperative and postoperative costs (ratio 1.3). Twelve patients with intraoperative adverse events were predicted to have poor outcomes versus 24 who did (P < .0001), indicating 12 “failures to rescue.”ConclusionsAdverse events still occur regularly during cardiac reoperation, are related to complexity of the procedure, and occur particularly during dissection and often when preventive strategies have not been used. Compensatory rescue measures are not always successful. Adverse events lead to poor patient outcome and higher cost

Luminescence from highly excited nanorings: Luttinger liquid description

We study theoretically the luminescence from quantum dots of a ring geometry. For high excitation intensities, photoexcited electrons and holes form Fermi seas. Close to the emission threshold, the single-particle spectral lines aquire weak many-body satellites. However, away from the threshold, the discrete luminescence spectrum is completely dominated by many-body transitions. We employ the Luttinger liquid approach to exactly calculate the intensities of all many-body spectral lines. We find that the transition from single-particle to many-body structure of the emission spectrum is governed by a single parameter and that the distribution of peaks away from the threshold is universal.Comment: 10 pages including 2 figure

Measurement of the Slope Parameter for the eta->3pi0 Decay in the pp->pp eta Reaction

The CELSIUS/WASA setup is used to measure the 3pi0 decay of eta mesons produced in pp interactions with beam kinetic energies of 1.36 and 1.45 GeV. The efficiency-corrected Dalitz plot and density distributions for this decay are shown, together with a fit of the quadratic slope parameter alpha yielding alpha = -0.026 +/- 0.010(stat) +/- 0.010(syst). This value is compared to recent experimental results and theoretical predictions.Comment: 4 pages, 7 Postscript figures, uses revtex4.st

Proceedings of the International Haemophilia Prophylaxis Study Group Meeting, November 2003, Montreal, PQ, Canada

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72691/1/j.1365-2516.2005.01053.x.pd