10,097 research outputs found

    A first attempt towards reliability-based calibration of Brazilian structural design codes

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    This paper addresses the reliability-based calibration of partial safety factors for Brazilian design codes NBR8681:2003 (Actions and Safety of Structures) and NBR8800:2008 (Design of Steel and Steel-Concrete Composite Structures). To the author's knowledge, these codes have never been subject to reliability-based calibration of partial and load combination factors. This paper represents a first effort in reaching this goal. The present calibration effort is based on actual data for wind loads in south east of Brazil, but uses mainly international data for other problem parameters. So far, the investigation is limited to structural steel members. The investigation leads to a set of optimized partial safety factors, which are compared to partial factors currently used in Brazilian design codes. Results show that the optimized set of partial factors leads to more uniform reliability for different design situations and load combinations. The investigation includes an analysis of the economical impact of replacing the current set of partial factors by the calibrated factors found in this paper. It is shown that, with an optimized set of partial safety factors, it is possible to maintain the current level of reliability and still produce a 5% average reduction in expenditure with structural materials, nationwide. The paper also points to general similarities between Brazilian design codes, the new generation of EUROCODES and American ANSI/AISC codes. These codes are compared in terms of their ability to produce uniform reliability for different design situations.CNPqCoordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES

    Tuberculose orbitária diagnosticada por imunohistoquímica

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    PURPOSE: To describe three cases of orbital tuberculosis, with their clinical characteristics and respective diagnostic procedures, showing the importance of histopathology for the correct diagnosis. PATIENTS AND METHODS: Three patients diagnosed and treated for orbital tuberculosis, in the "Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo" during the years of 1999 and 2001. RESULTS: All of the patients were female and referred a chronic evolution of swelling of one eyelid associated or not with other symptoms. They had not HIV infection. Two of them had positive epidemiology for tuberculosis. However, the search for systemic evidence of the disease and staining for bacilli (Ziehl-Neelsen method) were negative in all three patients. In all the cases, only the biopsy with immunohistochemical analysis could confirm the diagnosis. COMMENTS: Orbital involvement is a rare ocular manifestation of tuberculosis. Even in a tertiary hospital, few cases, if any, are diagnosed per year. However, the global incidence and prevalence of M. tuberculosis infections is not under control yet, and it has been a serious public health problem. Thus, one must be aware of the possibility of tuberculosis among the orbital diseases.OBJETIVO: Este estudo descreve 3 casos de tuberculose orbitária, com suas características clínicas, procedimentos diagnósticos, mostrando a importância da histopatologia para o diagnóstico correto. PACIENTES E MÉTODOS: Descrição de 3 casos de pacientes com tuberculose orbitária diagnosticada e tratada no Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo entre os anos 1999 e 2001 RESULTADOS: Todos os casos apresentaram-se como massa orbitária de evolução lenta e progressiva em pacientes de sexo feminino, sem doença pulmonar concomitante evidente. Duas tinham epidemiologia positiva para tuberculose. A pesquisa de bacilo álcool ácido resistente (BAAR), pelo método de Ziehl-Neelsen, entretanto, havia sido negativa em todos os casos. O diagnóstico etiológico nos três pacientes foi realizado pela identificação imunohistoquímica de bacilos tuberculínicos intracitoplasmáticos. COMENTÁRIOS: Baseando-se na elevada prevalência da tuberculose nos países em desenvovimento, associada ao aumento de sua incidência na última década, torna-se necessário considerá-la no diagnóstico diferencial das massas orbitárias em nosso meio

    The trauma and acute care surgeon in the COVID-19 pandemic era

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    The World Health Organization recognized in March 2020 the existence of a pandemic for the new coronavirus that appeared in China, in late 2019, and whose disease was named COVID-19. In this context, the SBAIT (Brazilian Society of Integrated Care for Traumatized Patients) conducted a survey with 219 trauma and emergency surgeons regarding the availability of personal protective equipment (PPE) and the role of the surgeon in this pandemic by means of an electronic survey. It was observed that surgeons have been acting under inadequate conditions, with a lack of basic supplies as well as more specific equipment such as N95 masks and facial shields for the care of potential victims who may be contaminated. The latter increases the risk of contamination of professionals, resulting in potential losses in the working teams. Immediate measures must be taken to guarantee access to safety equipment throughout the country, since all trauma victims and/or patients with emergency surgical conditions must be treated as potential carriers of COVID-19
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