8 resultados para Hahn, Archibald
em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo
Resumo:
Hematopoietic cell transplantation (HCT) is an emerging therapy for patients with severe autoimmune diseases (AID). We report data on 368 patients with AID who underwent HCT in 64 North and South American transplantation centers reported to the Center for International Blood and Marrow Transplant Research between 1996 and 2009. Most of the HCTs involved autologous grafts (n = 339); allogeneic HCT (n = 29) was done mostly in children. The most common indications for HCT were multiple sclerosis, systemic sclerosis, and systemic lupus erythematosus. The median age at transplantation was 38 years for autologous HCT and 25 years for allogeneic HCT. The corresponding times from diagnosis to HCT were 35 months and 24 months. Three-year overall survival after autologous HCT was 86% (95% confidence interval [CI], 81%-91%). Median follow-up of survivors was 31 months (range, 1-144 months). The most common causes of death were AID progression, infections, and organ failure. On multivariate analysis, the risk of death was higher in patients at centers that performed fewer than 5 autologous HCTs (relative risk, 3.5; 95% CI, 1.1-11.1; P = .03) and those that performed 5 to 15 autologous HCTs for AID during the study period (relative risk, 4.2; 95% CI, 1.5-11.7; P = .006) compared with patients at centers that performed more than 15 autologous HCTs for AID during the study period. AID is an emerging indication for HCT in the region. Collaboration of hematologists and other disease specialists with an outcomes database is important to promote optimal patient selection, analysis of the impact of prognostic variables and long-term outcomes, and development of clinical trials. Biol Blood Marrow Transplant 18: 1471-1478 (2012) (C) 2012 Published by Elsevier Inc. on behalf of American Society for Blood and Marrow Transplantation
Resumo:
Neutral-pion pi(0) spectra were measured at midrapidity (vertical bar y vertical bar < 0.35) in Au + Au collisions at root s(NN) = 39 and 62.4 GeV and compared with earlier measurements at 200 GeV in a transverse-momentum range of 1 < p(T) < 10 GeV/c. The high-p(T) tail is well described by a power law in all cases, and the powers decrease significantly with decreasing center-of-mass energy. The change of powers is very similar to that observed in the corresponding spectra for p + p collisions. The nuclear modification factors (RAA) show significant suppression, with a distinct energy, centrality, and p(T) dependence. Above p(T) = 7 GeV/c, R-AA is similar for root sNN = 62.4 and 200 GeV at all centralities. Perturbative-quantum-chromodynamics calculations that describe R-AA well at 200 GeV fail to describe the 39 GeV data, raising the possibility that, for the same p(T) region, the relative importance of initial-state effects and soft processes increases at lower energies. The p(T) range where pi(0) spectra in central Au + Au collisions have the same power as in p + p collisions is approximate to 5 and 7 GeV/c for root sNN = 200 and 62.4 GeV, respectively. For the root sNN = 39 GeV data, it is not clear whether such a region is reached, and the x(T) dependence of the x(T)-scaling power-law exponent is very different from that observed in the root sNN = 62 and 200 GeV data, providing further evidence that initial-state effects and soft processes mask the in-medium suppression of hardscattered partons to higher p(T) as the collision energy decreases.
Resumo:
We present measurements of the J/psi invariant yields in root s(NN) = 39 and 62.4 GeV Au + Au collisions at forward rapidity (1.2 < vertical bar y vertical bar < 2.2). Invariant yields are presented as a function of both collision centrality and transverse momentum. Nuclear modifications are obtained for central relative to peripheral Au + Au collisions (R-CP) and for various centrality selections in Au + Au relative to scaled p + p cross sections obtained from other measurements (R-AA). The observed suppression patterns at 39 and 62.4 GeV are quite similar to those previously measured at 200 GeV. This similar suppression presents a challenge to theoretical models that contain various competing mechanisms with different energy dependencies, some of which cause suppression and others enhancement. DOI: 10.1103/PhysRevC.86.064901
Resumo:
We report on charmonium measurements [J/psi (1S), psi' (2S), and chi(c) (1P)] in p + p collisions at root s = 200 GeV. We find that the fraction of J/psi coming from the feed-down decay of psi' and chi(c) in the midrapidity region (vertical bar y vertical bar < 0: 35) is 9.6 +/- 2.4% and 32 +/- 9%, respectively. We also present the p(T) and rapidity dependencies of the J/psi yield measured via dielectron decay at midrapidity (vertical bar y vertical bar < 0.35) and via dimuon decay at forward rapidity (1.2 < vertical bar y vertical bar < 2.2). The statistical precision greatly exceeds that reported in our previous publication [Phys. Rev. Lett. 98, 232002 (2007)]. The new results are compared with other experiments and discussed in the context of current charmonium production models.
Resumo:
The second Fourier component v(2) of the azimuthal anisotropy with respect to the reaction plane is measured for direct photons at midrapidity and transverse momentum (p(T)) of 1-12 GeV/c in Au + Au collisions at root s(NN) = 200 GeV. Previous measurements of this quantity for hadrons with p(T) < 6 GeV/c indicate that the medium behaves like a nearly perfect fluid, while for p(T) > 6 GeV/c a reduced anisotropy is interpreted in terms of a path-length dependence for parton energy loss. In this measurement with the PHENIX detector at the Relativistic Heavy Ion Collider we find that for p(T) > 4 GeV/c the anisotropy for direct photons is consistent with zero, which is as expected if the dominant source of direct photons is initial hard scattering. However, in the p(T) < 4 GeV/c region dominated by thermal photons, we find a substantial direct-photon v(2) comparable to that of hadrons, whereas model calculations for thermal photons in this kinematic region underpredict the observed v(2).
Resumo:
Background: Fungal infections are emerging as an important cause of human disease, especially among hospitalized patients with serious underlying disease and several risk factors. Aims: To evaluate epidemiological and clinical characteristics of patients with nosocomial candidiasis in university hospitals in Cuiaba - MT, Brazil. Methods: A descriptive study of 91 patients admitted to university hospitals in Cuiaba - MT, with clinical and laboratory diagnosis of nosocomial candidiasis, over a 20-month period. Results: A rate for nosocomial infections by Candida spp. of 5 per 1000 admissions, proportional mortality of 14.4% and lethality of 53.8% were determined. The patient age ranged from 29 days to 82 years-old, among which, 74.7% were adults and 25.3% children. The intensive care units contributed with the highest number of cases of infection by Candida spp. (69.2%). The most important underlying disease was gastrointestinal tract disease (11%). Prematurity and low birth weight were the most important risk factors among newborns. The use of antibiotics, invasive procedures, H-2 blockers, multiple blood transfusions and stay length of >= 21 days were the most frequent risk factors among adults. Candida albicans was the most common species in all cases. Conclusions: In this study, C. albicans was the most frequently detected species in candidiasis and risk factors increased the susceptibility of hospitalized patients to acquiring a nosocomial infection by Candida spp. (C) 2011 Revista Iberoamericana de Micologia. Published by Elsevier Espana, S.L. All rights reserved.
Resumo:
The PHENIX experiment has measured electrons and positrons at midrapidity from the decays of hadrons containing charm and bottom quarks produced in d + Au and p + p collisions at root S-NN = 200 GeV in the transverse-momentum range 0.85 <= p(T)(e) <= 8.5 GeV/c. In central d + Au collisions, the nuclear modification factor R-dA at 1.5 < p(T) < 5 GeV/c displays evidence of enhancement of these electrons, relative to those produced in p + p collisions, and shows that the mass-dependent Cronin enhancement observed at the Relativistic Heavy Ion Collider extends to the heavy D meson family. A comparison with the neutral-pion data suggests that the difference in cold-nuclear-matter effects on light- and heavy-flavor mesons could contribute to the observed differences between the pi(0) and heavy-flavor-electron nuclear modification factors R-AA. DOI: 10.1103/PhysRevLett.109.242301
Resumo:
Measurements of the anisotropy parameter v(2) of identified hadrons (pions, kaons, and protons) as a function of centrality, transverse momentum p(T), and transverse kinetic energy KET at midrapidity (vertical bar eta vertical bar < 0.35) in Au + Au collisions at root s(N N) = 200 GeV are presented. Pions and protons are identified up to p(T) = 6 GeV/c, and kaons up to p(T) = 4 GeV/c, by combining information from time-of-flight and aerogel Cerenkov detectors in the PHENIX Experiment. The scaling of v(2) with the number of valence quarks (n(q)) has been studied in different centrality bins as a function of transverse momentum and transverse kinetic energy. A deviation from previously observed quark-number scaling is observed at large values of KET/n(q) in noncentral Au + Au collisions (20-60%), but this scaling remains valid in central collisions (0-10%).