367 research outputs found
Patients with ischaemic, mixed and nephrotoxic acute tubular necrosis in the intensive care unit – a homogeneous population?
INTRODUCTION: Acute tubular necrosis (ATN) is usually studied as a single entity, without distinguishing between ischaemic, nephrotoxic and mixed aetiologies. In the present study we evaluated the characteristics and outcomes of patients with ATN by aetiological group. METHOD: We conducted a retrospective comparison of clinical features, mortality rates and risk factors for mortality for the three types of ATN in patients admitted to the general intensive care unit of a university hospital between 1997 and 2000. RESULTS: Of 593 patients with acute renal failure, 524 (88%) were classified as having ATN. Their mean age was 58 years, 68% were male and 52% were surgical patients. The overall mortality rate was 62%. A total of 265 patients (51%) had ischaemic ATN, 201 (38%) had mixed ATN, and 58 (11%) had nephrotoxic ATN. There were no differences among groups in terms of age, sex, APACHE II score and reason for ICU admission. Multiple organ failure was more frequent among patients with ischaemic (46%) and mixed ATN (55%) than in those with nephrotoxic ATN (7%; P < 0.0001). The complications of acute renal failure (such as, gastrointestinal bleeding, acidosis, oliguria and hypervolaemia) were more prevalent in ischaemic and mixed ATN patients. Mortality was higher for ischaemic (66%; P = 0.001) and mixed ATN (63%; P = 0.0001) than for nephrotoxic ATN (38%). When ischaemic ATN patients, mixed ATN patients and all patients combined were analyzed by multivariate logistic regression, the independent factors for mortality identified were different except for oliguria, which was the only variable universally associated with death (odds ratio [OR] 3.0, 95% confidence interval [CI] 1.64–5.49 [P = 0.0003] for ischaemic ATN; OR 1.96, 95% CI 1.04–3.68 [P = 0.036] for mixed ATN; and OR 2.53, 95% CI 1.60–3.76 [P < 0.001] for all patients combined]). CONCLUSION: The frequency of isolated nephrotoxic ATN was low, with ischaemic and mixed ATN accounting for almost 90% of cases. The three forms of ATN exhibited different clinical characteristics. Mortality was strikingly higher in ischaemic and mixed ATN than in nephrotoxic ATN. Although the type of ATN was not an independent predictor of death, the independent factors related to mortality were different for ischaemic, mixed and all patients combined. These data indicate that the three types of ATN represent different patient populations, which should be taken into consideration in future studies
α-particle production in 6He + 120Sn collisions
The collision 6He+120Sn has been investigated at four energies near the Coulomb barrier. A large yield of α particles has been detected, with energies around the energy of the scattered 6He beam. The energy and angular distributions of the α particles have been analyzed and compared with breakup and neutron transfer calculations.Ministerio de Ciencia e Innovación (España) FPA2006-13807-c02-01Junta de AndalucÃa P07-FQM-02894Ministerio de Educación y Ciencia (España) PCI2006-A7-0654Programa Consolider-Ingenio 2010 (España) CSD2007-0004
Analysis of the elastic scattering measured with a 23.7 MeV 7Be beam on a 9Be target.
We present new data for the reaction 7Be+9Be measured at Elab =23.7 MeV. The elastic
scattering angular distribution has been analyzed using the phenomenological optical model and
the coupled-channels method. In the latter approach, we assumed a two-cluster model of the 7Be nucleus, and we included explicitly the ground state and first excited state of this nucleus. The contribution of the inelastic excitation of the 7Be nucleus to the quasielastic cross sections has been investigated.Ministerio de Educación y Ciencia (MEC). España FPA2006-13807-c02-01Spanish Consolider-Ingenio programme CPAN CSD2007-0004
Evidence of the effect of strong stripping channels on the dynamics of the 8 Li + 58Ni reaction
The 8
Li + 58Ni collision is investigated at 23.9, 26.1, 28.7, and 30 MeV bombarding energies. Quasielastic
angular distributions and the singles 7
Li angular and energy distributions are presented. Coupled-reaction
channels (CRC) calculations, which include the coupling of the elastic channel to 59Ni = 58Ni + n states above
and below the neutron threshold, provide a simultaneous description of the quasielastic and transfer distributions
and evidence the strong effect of the one-neutron transfer/breakup channels on the quasielastic scattering. The 7
Li angular and energy distributions have been also successfully analyzed combining the continuum discretized
coupled channels (CDCC) method, for the elastic breakup, and the IAV model of Ichimura, Austern, and Vincent
[Phys. Rev. C 32, 431 (1985)], for the nonelastic breakup. These calculations indicate that most of the 7
Li yields
are due to nonelastic breakup contributions (transfer), whereas elastic breakup plays a minor role.Fundação de Amparo à Pesquisa do Estado de São Paulo, FAPESP (Brazil), Contratos No. 2019/02759-0, No. 2019/07767-1, No. 2016/17612-7 y No. 2013/22100-7Coordenação de Aperfeiçoamento de Pessoal de Nével Superior, Brasil (CAPES), código de financiación: 88887.355019/2019Ministerio de Ciencia, Innovación y Universidades de España. proyecto No. FIS2017-88410-PFondo Europeo de Desarrollo Regional (FEDER)Programa Horizon 2020 de la Unión Europea No. 65400
Elastic scattering and total reaction cross section of 6He + 120Sn
The elastic scattering of 6He on 120Sn has been measured at four energies above the Coulomb barrier using the 6He beam produced at the RIBRAS (Radioactive Ion Beams in Brasil) facility. The elastic angular distributions have been analyzed with the optical model and three- and four-body continuum-discretized coupled-channels calculations. The total reaction cross sections have been derived and compared with other systems of similar masses.Ministerio de Educación y Ciencia PCI2006-A7-0654Ministerio de Ciencia e Innovación FPA2006-13807-c02-01Junta de AndalucÃa P07-FQM-02894Programa Consolider-Ingenio 2010 CSD2007-0004
Experimental study of 6He + 9Be elastic scattering at low energies
New data for the H6e+9Be reaction at Elab=16.2 and 21.3 MeV have been taken and analyzed. The effect of the collective couplings to the excited states of the target has been studied by means of coupled-channels calculations, using a double-folding potential for the bare interaction between the colliding nuclei, supplemented with a phenomenological imaginary part of Woods-Saxon type. In addition, three- and four-body continuum-discretized coupled-channels calculations have been performed to investigate the effect of the projectile breakup on the elastic scattering. Both effects, the coupling to target and projectile excited states, are found to affect significantly the elastic scattering. The trivial local polarization potential extracted from the continuum-discretized coupled-channels calculations indicates that continuum couplings produce a repulsive real part and a long-range imaginary part in the projectile-target interaction.Junta de AndalucÃaMinisterio de Ciencia e Innovación (España) FPA2009-07653 PCI2006-A7-0654Programa Consolider-Ingenio 2010 CSD2007-0004
Quantum Electronics
Contains research objectives and summary of research on eight projects in three sections and reports on two research projects.U. S. Air Force - Office of Scientific Research (Contract F44620-71-C-0051)Joint Services Electronics Program (Contract DAAB07-74-C-0630)University of California, Livermore (Subcontract No. 7877409)U. S. Army Research Office - Durham (Contract DAHC04-72-C-0044
Lack of lethal and sublethal effects of Cry1Ac Bt-toxin on larvae of the stingless bee Trigona spinipes
Abstract -Stingless bees, particularly Trigona spinipes, are important pollinators in tropical ecosystems and are potentially affected by environmental contaminants. In this study, we tested the possible negative effects on T. spinipes larvae of the ingestion of a diet contaminated with Cry1Ac Bt-toxin. This toxin is expressed in genetically modified cotton plants. A method of rearing stingless bee larvae is described in this paper. The larvae were provided with either pure larval diet, diluted larval diet, or larval diet diluted in a Cry1Ac solution compatible with the lethal pest-exposure level (50 μg/mL). Cry1Ac ingestion did not impair the development of worker larvae, but the diluted diet slightly increased larval mortality. These results indicate that harmful effects on stingless bee larvae due to the ingestion of pollen-expressed Cry1Ac toxin are unlikely under field conditions. Bacillus thuringiensis toxin / transgenic plants / environmental impact / native pollinator / risk assessmen
Spin-orbit effects in the 8Li+58Ni elastic scattering
In this work we present an elastic scattering angular distribution for the 8Li+58Ni
system measured at Elab = 26.1 MeV. The 8Li beam was produced in the Radioactive Ion
Beams in Brasil (RIBRAS) facility using the 7Li primary beam delivered by the 8-UD Pelletron
accelerator. The angular distribution covers the angular range from 20 to 85 degrees in the
center of mass frame. The data have been analysed by optical model and coupled channels
calculations, including couplings to low-lying states in 8Li and the spin-orbit interaction. Our
results indicate that the inclusion of the spin-orbit interaction in the calculations is important
to describe the data at backward angles.Coordenação de Aperfeiçoamento de Pessoal de Nivel Superior (CAPES) y Funda¸c˜ao de Amparo `a Pesquisa do Estado de S˜ao Paulo (FAPESP)013/22100-7 y 2016/17612-7Coordenação de Aperfeiçoamento de Pessoal de Nivel Superior de Brasil (CAPES) y Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)-013/22100-7 y 2016/17612-
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