52 research outputs found
Parton coalescence at RHIC
Using a covariant coalescence model, we study hadron production in
relativistic heavy ion collisions from both soft partons in the quark-gluon
plasma and hard partons in minijets. Including transverse flow of soft partons
and independent fragmentation of minijet partons, the model is able to describe
available experimental data on pion, kaon, and antiproton spectra. The
resulting antiproton to pion ratio is seen to increase at low transverse
momenta and reaches a value of about one at intermediate transverse momenta, as
observed in experimental data at RHIC. A similar dependence of the antikaon to
pion ratio on transverse momentum is obtained, but it reaches a smaller value
at intermediate transverse momenta. At high transverse momenta, the model
predicts that both the antiproton to pion and the antikaon to pion ratio
decrease and approach those given by the perturbative QCD. Both collective flow
effect and coalescence of minijet partons with partons in the quark-gluon
plasma affect significantly the spectra of hadrons with intermediate transverse
momenta. Elliptic flows of protons, Lambdas, and Omegas have also been
evaluated from partons with elliptic flows extracted from fitting measured pion
and kaon elliptic flows, and they are found to be consistent with available
experimental data.Comment: 12 pages, 11 figure
New results from NA49
Recent results of the NA49 experiment are presented. These cover first results on pion and kaon production, HBT, and charge fluctuations from Pb+Pb reactions at 40A GeV and their comparison to 158A GeV beam energy. Furthermore a study on baryon number transfer in p+p, centrality selected p+Pb and Pb+Pb collisions at 158A GeV and new results on the system size dependence of kaon yields, including C+C and Si+Si data, are presented. Additionally, a first result on correlations is shown
Chemical Derivatization Processes Applied to Amine Determination in Samples of Different Matrix Composition
Flame Ionization Detector Response Factors Using the Effective Carbon Number Concept in the Quantitative Analysis of Esters
Inhibition of Enzymatic Browning in Fresh Fruit and Vegetable Juices by Soluble and Insoluble Forms of β-Cyclodextrin Alone or in Combination with Phosphates
Risk of Major Hemorrhage after Kidney Transplantation
<b><i>Background:</i></b> Major hemorrhagic events are associated with significant morbidity and mortality. We examined the three-year cumulative incidence of hospitalization with major nontraumatic hemorrhage after kidney transplantation. <b><i>Methods:</i></b> We performed a retrospective cohort study using healthcare administrative data of all adult-incident kidney-only transplantation recipients in Ontario, Canada from 1994 to 2009. We calculated the three-year cumulative incidence, event rate, and incident rate ratio of hospitalization with major hemorrhage, its subtypes and those undergoing a hemorrhage-related procedure. Results were stratified by patient age and donor type and compared to a random and propensity-score matched sample from the general population. <b><i>Results:</i></b> Among 4,958 kidney transplant recipients, the three-year cumulative incidence of hospitalization with nontraumatic major hemorrhage was 3.5% (95% confidence interval [CI] 3.0-4.1%, 12.7 events per 1,000 patient-years) compared to 0.4% (95% CI 0.4-0.5%) in the general population (RR = 8.2, 95% CI 6.9-9.7). The crude risk of hemorrhage was 3-9-fold higher in all subtypes (upper/lower gastrointestinal, intra-cranial) and 15-fold higher for gastrointestinal endoscopic procedures compared to the random sample from the general population. After propensity score matching, the relative risk for major hemorrhage and its subtypes attenuated but remained elevated. The cumulative incidence of hemorrhage was higher for older individuals and those with a deceased donor kidney. <b><i>Conclusion:</i></b> Kidney transplantation recipients have a higher risk of hospitalization with hemorrhage compared to the general population, with about 1 in 30 recipients experiencing a major hemorrhage in the three years following transplant.</jats:p
Measurement of Hydroxyl-Radical Formation in the Rat Striatum by In Vivo Microdialysis and GC-MS
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