788 research outputs found

    Fire safety applications for spacecraft

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    Fire safety for spacecraft is reviewed by first describing current practices, many of which are adapted directly from aircraft. Then, current analyses and experimental knowledge in low-gravity combustion, with implications for fire safety are discussed. In orbiting spacecraft, the detection and suppression of flames are strongly affected by the large reduction in buoyant flows under low gravity. Generally, combustion intensity is reduced in low gravity. There are some notable exceptions, however, one example being the strong enhancement of flames by low-velocity ventilation flows in space. Finally, the future requirements in fire safety, particularly the needs of long-duration space stations in fire prevention, detection, extinguishment, and atmospheric control are examined. The goal of spacecraft fire-safety investigations is the establishment of trade-offs that promote maximum safety without hampering the useful human and scientific activities in space

    Effect of age and sex on glomerular filtration rate measured by 51Cr-EDTA

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    l. The effect of age and sex on glomerular filtration rate (GFR) was measured by the 51Cr-EDTA radioisotopic method in 76 normal individuals (43 women and 33 men). 2. Age has a significant effect on GFR. Subjects aged 41 to 60 years have GFR values [104.5 ± 16.5 ml min"1 (1.73 m2)" 1 , N- 43]lower than younger individuals aged 20 to 40 years [116.6 ± 11.2 ml min"1 (1.73 m2 )" 1 , N- 33]. GFR decreases after 40 years of age by approximately 6.0 ml min"1 (1.73 m2)"1 per decade. 3. GFR values in women [105.9 ± 16.0 ml min" 1 (1.73 m2)" 1 , N- 43] were lower when compared to men [114.8 ± 14.3 ml min"1 (1.73 m2)" 1 , N = 33]. 4. We conclude that the effect of sex and age must be taken into account when establishing reference values for GFR

    Risk factors for development of proteinuria by type II (non-insulin dependent) diabetic patients

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    I. Renal involvement in non-insulin dependent diabetes mellitus patients is the single most important cause of renal failure. The aim of this study was to evaluate the clinical features and to assess the risk factors for the development of proteinuria by non-insulin dependent diabetic patients. 2. Risk factors (expressed as an odds ratio) were calculated by multiple logistic regression analysis taking into account age, sex, body mass index, known duration of diabetes, presence of arterial hypertension, fasting plasma glucose, cholesterol and triglycerides as independent variables and proteinuria as the dependent variable. Sixty-four normoalbuminuric (24-h albumin excretion rate 0.5 g, 31 females, mean age 59.3 years) were studied. 3. Protein uric patients were older, with a longer mean known duration of diabetes (12.4 vs 5.6 years), higher mean fasting plasma glucose (214 vs 168 mg/dl) and plasma creatinine (1.5 vs 1.1 mg/dl) and more frequently presented diabetic retinopathy (94% vs 23% ), peripheral neuropathy (94% vs 23%) and arterial hypertension (73% vs 16%) than normoalbuminuric patients. Age >50 years, body mass index >28.6 kgfm2, known duration of diabetes> 10 years, presence of arterial hypertension, and fasting plasma glucose> 160 mg/dl were significantly and independently associated with development of proteinuria

    Participation of women in HIV clinical trials: the IPEC-FIOCRUZ experience

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    Jordan E Lake1, Ruth K Friedman2, Cynthia B Cunha2, Sandra W Cardoso2, Valdilea G Veloso2, Judith S Currier1, Beatriz Grinsztejn21Division of Infectious Diseases, University of California at Los Angeles, Los Angeles, CA, USA; 2Fundação Oswaldo Cruz – Instituto de Pesquisa Clínica Evandro Chagas/IPEC, Rio de Janeiro, State of Rio de Janeiro, BrazilBackground: Fifty percent of people living with human immunodeficiency virus (HIV) or acquired immunodeficiency syndrome (AIDS) worldwide are female. In Brazil, for example, 240,000 women are infected with HIV, rates of infection in women have increased over the last two decades, and addressing HIV prevention and treatment for women at risk for, or living with, HIV/AIDS remains a challenge. To better address the needs of women living with HIV in Brazil, the Instituto de Pesquisa Clínica Evandro Chagas – Fundação Oswaldo Cruz (IPEC-FIOCRUZ) HIV Women’s Cohort was established in 1996 to study the natural history of women seeking HIV care. This analysis describes the characteristics of women in the cohort who participated in HIV clinical trials between 1999 and 2008.Methods: A total of 736 Women’s Cohort participants were in active follow-up and 665 participants from the Women’s Cohort were included in univariable and multivariable analyses to determine socioeconomic and sociodemographic factors associated with women’s participation in HIV clinical trials at our site.Results: Of the complete cohort, 23% participated in a clinical trial between January 1999 and July 2008. Odds of participation decreased for women who were younger than 35 years old, currently employed, had an HIV-positive sexual partner, and/or who reported a lifetime history of illicit drug use. Alternatively, the odds of participation increased for women who had more than 8 years of formal education, were living independently, and/or were married or cohabitating.Conclusion: The rate of participation in HIV clinical trials by women in the IPEC-Fiocruz Cohort was similar to other published cohorts, but identification of local risk factors and barriers to participation remains important. Our analysis offers a novel description of the factors associated with participation in HIV clinical trials among women in care at IPEC-FIOCRUZ in Rio de Janeiro, Brazil.Keywords: AIDS, Brazil, South America, clinical trial participation&nbsp

    Comparative Genomic Hybridization Analysis of Astrocytomas: Prognostic and Diagnostic Implications.

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    Astrocytoma is comprised of a group of common intracranial neoplasms that are classified into four grades based on the World Health Organization histological criteria and patient survival. To date, histological grade, patient age, and clinical performance, as reflected in the Karnofsky score, are the most reliable prognostic predictors. Recently, there has been a significant effort to identify additional prognostic markers using objective molecular genetic techniques. We believe that the identification of such markers will characterize new chromosomal loci important in astrocytoma progression and aid clinical diagnosis and prognosis. To this end, our laboratory used comparative genomic hybridization to identify DNA sequence copy number changes in 102 astrocytomas. Novel losses of 19p loci were detected in low-grade pilocytic astrocytomas and losses of loci on 9p, 10, and 22 along with gains on 7, 19, and 20 were detected in a significant proportion of high-grade astrocytomas. The Cox proportional hazards statistical modeling showed that the presence of +7q and -10q comparative genomic hybridization alterations significantly increased a patient\u27s risk of dying, independent of histological grade. This investigation demonstrates the efficacy of comparative genomic hybridization for identifying tumor suppressor and oncogene loci in different astrocytic grades. The cumulative effect of these loci is an important consideration in their diagnostic and prognostic implications

    Incidência e preditores de gestação em mulheres com HIV/Aids no Rio de Janeiro

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    OBJETIVO: Identificar incidencia y predictores de la primera gestación entre mujeres con VIH/Sida. MÉTODOS: Estudio prospectivo de cohorte conducido en Rio de Janeiro, Sureste de Brasil, entre 1996 y 2003. El estudio incluyó 225 mujeres acompañadas hasta la primera gestación o hasta el primer evento considerado censura (histerectomía, ligadura tubárica, menopausia, 50 años de edad, pérdida de acompañamiento, óbito o final de diciembre de 2003). Se estimaron las tasas de incidencia de gestación y de aborto, y se usaron modelos de riesgos proporcionales de Cox para identificar las características de la visita de inclusión asociadas con el riesgo de gestación. RESULTADOS: Las mujeres fueron acompañadas por 565 persona/años, con promedio de acompañamiento de 3 años por mujer. La edad promedio fue de 32 años (DP:7), y 54,7% eran blancas. Sesenta gestaciones fueron observadas en 39 mujeres y 18 resultaron en abortos inducidos (tasas de incidencia de 6,9% y 2,1% mujeres/año, respectivamente). Las gestaciones repetidas ocurrieron en 33,3% de las mujeres (13/39). Fue observado el mayor riesgo de gestación entre mujeres jóvenes (HR=3,42; IC 95%:1,69;6,95) y entre aquellas que vivían con sus parejas (HR=1,89; IC 95%: 1,00;3,57). El menor riesgo de gestación estuvo asociado a la mayor escolaridad (HR=0,43; IC95%:0,19;0,99) y al uso de terapia antirretroviral (HR=0,61; IC95%:0,31;1,17). CONCLUSIONES: La incidencia de gestación en la cohorte fue menor al compararse con aquella observada en la población general. Características sociodemográficas deben ser consideradas en el manejo de los deseos reproductivos de mujeres VIH-positivas en edad reproductiva. Los programas de VIH/SIDA deben incluir consejos reproductivos y contraceptivos para prevenir la transmisión del VIH para sus parejas y prole.OBJETIVO: Identificar incidência e preditores incidência da primeira gestação entre mulheres com HIV/Aids. MÉTODOS: Estudo prospectivo de coorte conduzido entre 1996 e 2003 no Rio de Janeiro, RJ, com 225 mulheres acompanhadas até a primeira gestação ou até o primeiro evento considerado censura (histerectomia, ligadura tubárea, menopausa, 50 anos de idade, perda de acompanhamento, óbito ou final de dezembro de 2003). Taxas de incidência de gestação e de aborto foram estimadas e modelos de riscos proporcionais de Cox foram usados para identificar as características da visita de inclusão associadas com o risco de gestação. RESULTADOS: As mulheres foram acompanhadas por 565 pessoas/ano, com média de acompanhamento de 3 anos por mulher. A idade média foi de 32 anos (DP: 7) e 54,7% eram brancas. Sessenta gestações foram observadas em 39 mulheres e 18 resultaram em abortos induzidos (taxas de incidência de 6,9% e 2,1% mulheres/ano, respectivamente). Gestações repetidas ocorreram em 33,3% das mulheres (13/39). Maior risco de gestação foi observado entre mulheres jovens (HR = 3,42; IC95%:1,69;6,95) e entre aquelas vivendo com seus parceiros (HR = 1,89; IC95%:1,00;3,57). Menor risco de gestação esteve associado à maior escolaridade (HR = 0,43; IC95%:0,19;0,99) e ao uso de terapia anti-retroviral (HR = 0,61; IC95%:0,31;1,17). CONCLUSÕES: A incidência de gestação na coorte foi menor se comparada àquela observada na população geral. Características sociodemográficas devem ser consideradas no manejo dos desejos reprodutivos de mulheres HIV-positivas em idade reprodutiva. Os programas de HIV/Aids devem incluir aconselhamento reprodutivo e contraceptivo para prevenir a transmissão do HIV para seus parceiros e prole.OBJECTIVE: To assess incidence and predictors of first pregnancy among women with HIV/AIDS. METHODS: Prospective cohort study was conducted in Rio de Janeiro, southeastern Brazil, between 1996 and 2003. This study comprised 225 women with HIV/AIDS followed up until their first pregnancy or first censored event (hysterectomy, tubal ligation, menopause, 50 years of age, loss to follow-up, death or the end of December 2003). Pregnancy and abortion rates were estimated, and Cox proportional hazards models were used to identify baseline characteristics associated with pregnancy risk. RESULTS: The women were followed up for 565 person/years with a median follow-up of 3 years per women. The mean age was 32 years (SD: 7), and 54.7% were white. There were 60 pregnancies in 39 women, and 18 were terminated (induced abortions), accounting for a rate of 6.9% and 2.1% women/year, respectively. Repeated pregnancies occurred in 33.3% of the women (13/39). Higher pregnancy risk was seen among younger women (HR=3.42; 95%CI: 1.69;6.95) and those living with their partners (HR=1.89; 95%CI: 1.00;3.57). Lower pregnancy risk was associated with higher education level (HR=0.43; 95%CI: 0.19;0.99) and use of antiretroviral therapy (HR=061; 95%CI: 0.31;1.17). CONCLUSIONS: Lower pregnancy rates were found in our cohort than in the general population. Sociodemographic characteristics should be taken into consideration in the management of reproductive health in HIV-positive childbearing age women. Reproductive and family planning counseling must be incorporated into HIV/AIDS programs for women to help preventing HIV transmission to their partners and offspring
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