44 research outputs found

    Microwave plasma chemical vapour deposition diamond nucleation on ferrous substrates with Ti and Cr interlayers

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    Diamond-coated steel is considered an important issue in synthetic diamond technology due to the great economical importance of enhancing the wear resistance and surface hardness of commercial Fe-based alloys. However, direct diamond coating by chemical vapour deposition (CVD) is rather problematic-adhesion and growth are seriously affected. The use of interlayers is a common approach to minimise these problems. This work reports an investigation on the establishment of good nucleation and growth conditions of diamond films by microwave plasma CVD (MPCVD) on ferrous substrates coated with Ti and Cr interlayers. Commercial grade ferrous substrates were pre-coated with commercial interlayers by sputtering (Ti, Cr) and electroplating (Cr) techniques. Steel substrates led to better results than iron cast substrates. The best films were obtained on Ti pre-coated steel substrate. The results on Cr interlayers pointed to the advantage of electroplating over the physical vapour deposition (PVD) sputtering. From the two selected parameter sets for diamond deposition, the one using lower power level conducted to the best results. Initial roughness and growth parameters were found to counteract on the uniformity of the diamond films. The morphology was studied by scanning electron microscopy (SEM), the roughness was estimated by profilometry, while diamond quality and stress state were evaluated by mu-Raman spectroscopy. (C) 2002 Elsevier Science B.V. All rights reserved

    Hypericum sp.: essential oil composition and biological activities

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    Phytochemical composition of Hypericum genus has been investigated for many years. In the recent past, studies on the essential oils (EO) of this genus have been progressing and many of them have reported interesting biological activities. Variations in the EO composition of Hypericum species influenced by seasonal variation, geographic distribution, phenological cycle and type of the organ in which EO are produced and/or accumulated have also been reported. Although many reviews attributed to the characterization as well as biological activities of H. perforatum crude extracts have been published, no review has been published on the EO composition and biological activities of Hypericum species until recently (Crockett in Nat Prod Commun 5(9):1493–1506, 2010; Bertoli et al. in Global Sci Books 5:29–47, 2011). In this article, we summarize and update information regarding the composition and biological activities of Hypericum species EO. Based on experimental work carried out in our laboratory we also mention possible biotechnology approaches envisaging EO improvement of some species of the genus.Fundação para a Ciência e a Tecnologia (FCT) - project PTDC/AGR AAM/70418/2006, SFRH/BD/ 13283/2003

    Maior sobrevida em pacientes com marcadores imunogenéticos de rápida progressão para a AIDS: subsídios para a assistência de enfermagem

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    This study sought subsidies for improving nursing care programs for AIDS patients and aimed to verify the influence of changes in sexual behavior, including the adoption of safe sex practices, associated with the survival of AIDS patients with immunogenetic markers of rapid disease progression. 27 AIDS patients were interviewed, with genetic predisposition to rapid progression to AIDS. Genes were typified through the polymerase chain reaction. In spite of the presence of immunogenetic factors, associated with individual predisposition to a rapid evolution of the disease, changes in sexual behavior, including safe sex practices and antiretroviral therapy, may be related to greater survival. This suggests that counseling, detection of risk attitudes and health education, focusing on positive health behavior, are tools nursing must use with HIV-positive patients, with a view to better quality of life and greater survival among these individuals, even among those with genetic predisposition to rapid disease progression.Los autores buscan apoyo para el perfeccionamiento de programas de enfermería, orientados a pacientes con SIDA. La finalidad de este estudio fue la de verificar la influencia del comportamiento sexual en la supervivencia de pacientes con SIDA, portadores de genes asociados a la rápida progresión de la enfermedad. Fueron estudiados 27 pacientes con SIDA. Las tipificaciones de genes fueron realizadas por la reacción en cadena de la polimerasa. No obstante la presencia de factores inmunogenéticos, asociados a la predisposición individual a la rápida evolución de la enfermedad, cambios en el comportamiento sexual, con prácticas sexuales seguras y el uso de terapia antiretroviral, pueden estar relacionados con mayor supervivencia. La orientación, la detección de actitudes de riesgo y la educación de salud con enfoque en el comportamiento positivo de salud son herramientas que la enfermería debe utilizar con portadores del VIH, buscando la mejor calidad de vida y mayor supervivencia de esos individuos, incluso en aquellos que tienen predisposición genética a la rápida progresión de la enfermedad.Com enfoque em subsídios para o aperfeiçoamento de programas de enfermagem, direcionados a pacientes com aids, o presente estudo foi realizado com o objetivo de verificar a influência do comportamento sexual na sobrevida de pacientes com aids, portadores de genes associados à rápida progressão da doença. Foram entrevistados 27 pacientes com aids, geneticamente predispostos à rápida progressão da doença. As tipificações dos genes foram realizadas pela reação em cadeia da polimerase. Os resultados sugerem que, apesar da presença de fatores imunogenéticos, associados à predisposição individual para rápida evolução da doença, as mudanças do comportamento sexual, com adoção de práticas de sexo seguro, junto ao uso da terapia anti-retroviral, podem estar relacionadas com maior sobrevida. O aconselhamento, a detecção de atitudes de risco e a educação para saúde, enfocando o comportamento positivo de saúde, são ferramentas que a enfermagem deve utilizar a portadores do HIV, visando à melhor qualidade de vida e maior sobrevida desses indivíduos, mesmo naqueles geneticamente predispostos à rápida progressão da doença

    Genetic diversity among volunteer donors of bone marrow in southeastern Brazil, according to the HLA system

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    CONTEXTO E OBJETIVO:Para a realização de transplantes de medula óssea com material alogênico, é necessária a verificação de histocompatibilidade das moléculas do sistema HLA (human leukocyte antigen), fundamental para o sucesso desses transplantes. O objetivo desta pesquisa foi caracterizar os doadores de medula óssea segundo gênero, idade, etnia e grupos HLA de um centro regional de hemoterapia brasileiro.TIPO DE ESTUDO E LOCAL:Estudo descritivo dos doadores cadastrados em um centro regional de hemoterapia de um hospital público universitário da região Sudeste do Brasil.MÉTODOS:Foram consultadas as fichas dos 66.780 doadores cadastrados entre 2005 e junho de 2011 e tabuladas as variáveis estudadas.RESULTADOS:Encontrou-se distribuição equilibrada entre os gêneros, e 82,8% dos doadores tinham até 45 anos de idade. Quanto à etnia auto-referida, 77,3% se apresentaram como brancos, 15,0% como pardos, 5,7% como negros, os 2% restantes dividindo-se em outras etnias. Quanto à caracterização imunogenética, no grupo alélico HLA-A, o mais frequente foi o HLA-A*02, com 39,20%; no grupo alélico HLA-B, o mais comum foi o HLA-B*35, com 14,18%; no grupo alélico HLA-DRB1, o mais frequente foi o HLA-DRB1*03, com 17,03% do total de doadores. Quando esses resultados são comparados com os dados do cadastro nacional de doadores (REDOME), observam-se diferenças demográficas e imunogenéticas, que se explicam pelo histórico de imigração da região de Ribeirão Preto, no Sudeste brasileiro.CONCLUSÕES:Os resultados encontrados reforçam a importância de conhecer o perfil demográfico e imunogenético das regiões do Brasil, para reduzir o tempo de espera por um doador histocompatível.CONTEXT AND OBJECTIVE:Checking the histocompatibility of the molecules of the human leukocyte antigen (HLA) system is vital for performing bone marrow transplantation with allogeneic material. The objective of this study was to characterize bone marrow donors according to gender, age, ethnicity and HLA groups at a regional hemotherapy center in Brazil.DESIGN AND SETTING:Descriptive study on registered donors at a regional hemotherapy center in a public university hospital in the southeastern region of Brazil.METHODS:The records of 66,780 donors who were registered between 2005 and June 2011 were consulted, and the variables studied were tabulated.RESULTS:There were equal numbers of male and female donors and 82.8% of them were under 45 years of age. In terms of ethnicity, 77.3% declared themselves to be white, 15.0% mixed race, 5.7% black and 2% others. In terms of immunogenetic characterization, the most frequent HLA-A allelic group was HLA-A*02, with 39.20% of the donors; in the HLA-B allelic group, the most common was HLA-B*35, with 14.18%; while in the HLA-DRB1 allelic group, the most frequent was HLA-DRB1*03, with 17.03%. Comparison between these results and data from the Brazilian Bone Marrow Donor Registry (REDOME) showed that there were demographic and immunogenetic differences due to the history of immigration in the region of Ribeirão Preto, in southeastern Brazil.CONCLUSIONS:The results reinforce the importance of understanding the demographic and immunogenic profile of regions of Brazil, in order to reduce the waiting time for a histocompatible donor.Universidade de São Paulo Faculdade de Medicina de Ribeirão Preto Biomedical Scientist in the Regional Center for HematologyUniversidade Estadual Paulista Department of Biological SciencesUniversidade Estadual Paulista Department of Social DentistryUniversidade Estadual Paulista Department of Biological SciencesUniversidade Estadual Paulista Department of Social Dentistr

    Evaluation of babassu meal in feed for layer hens during the growth phase

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    Studies were conducted to evaluate the nutritional value and inclusion levels of babassu meal (BM) in the diet of grower layer pullets in substitution to wheat meal. Digestibility, metabolism and growth trials were conducted. Twelve cecectomized roosters were used in the digestibility assay to determine the coefficients of standardized digestibility of amino acids (CSDAA). The metabolism trial was conducted with 30 adult roosters to determine the apparent metabolizable energy corrected for nitrogen (AMEn) of BM. A growth trial was performed to determine replacement levels of wheat midds by BM diet using 360 six-week-old commercial layer pullets. BM was included at the 0, 75 and 150 g/kg of BM, during grower and development rearing phases, respectively. Feed intake, body weight gain, and feed conversion were evaluated. BM AMEn was determined as 1,474 kcal/kg, on as-fed basis. The CSDAA determined for BM were below 88% for all AA. The inclusion of BM in the feed of grower layers (7-18 week) significantly decreased feed intake (p < 0.05), but significantly improved body weight gain and feedconversion ratio (p < 0.05) at 15% inclusion level. Considering the nutritional value and performance results, BM can replace wheat midds in diets of grower layer pullets.Universidade Estadual do Maranhão Departamento de ZootecniaUniversidade Estadual Paulista Faculdade de Ciências Agrárias e VeterináriaUniversidade Estadual Paulista Faculdade de Ciências Agrárias e Veterinári
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