493 research outputs found

    High yielding synthesis of N-ethyl dehydroamino acids

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    Recently we reported the use of a sequence of alkylation and dehydration methodologies to obtain N-ethyl-α, β-dehydroamino acid derivatives. The application of this N-alkylation procedure to several methyl esters of β, β-dibromo and β--bromo, β-substituted dehydroamino acids protected with standard amine protecting groups was subsequently reported. The corresponding N-ethyl, β-bromo dehydroamino acid derivatives were obtained in fair to high yields and some were used as substrates in Suzuki cross coupling reactions to give N-ethyl, β, β-disubstituted dehydroalanine derivatives. Herein, we further explore N-ethylation of β-halo dehydroamino acid derivatives using triethyloxonium tetrafluoroborate as alkylating agent but substituting N,N-diisopropylethylamine for potassium tert-butoxide as auxiliary base. In these conditions, for all β-halo dehydroamino acid derivatives, reactions were complete and the N-ethylated derivative could be isolated in high yield. This method was also applied for N-ethylation of non-halogenated dehydroamino acids. Again, with all compounds the reactions were complete and the N-ethyl dehydroamino acid derivatives could be isolated in high yields. Some of these N-ethyl dehydroamino acid methyl ester derivatives were converted in high yields to their corresponding acids and coupled to an amino acid methyl ester to give N-ethyl dehydrodipeptide derivatives in good yields. Thus, this method constitutes a general procedure for high yielding synthesis of N-ethylated dehydroamino acids, which can be further applied in peptide synthesis.Foundation for Science and Technology (FCT)-Portugal and Fundo Europeu de Desenvolvimento Regional (FEDER) for financial support to Chemistry Centre of University of Minho. The NMR spectrometer Bruker Avance II+ 400 is part of the National NMR Network and was purchased in the framework of the National Program for Scientific Re-equipment; contract REDE/1517/RMN/2005, with funds from POCI 2010, FEDER and FCT

    Large volume leukapheresis for autologous peripheral blood stem cell collection in children weighting less than 25 kg

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    Universidade Federal de São Paulo, GRAACC, Pediat Oncol Inst, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Pathol, São Paulo, BrazilUniversidade Federal de São Paulo, GRAACC, Pediat Oncol Inst, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Pathol, São Paulo, BrazilWeb of Scienc

    Climate services in Brazil: Past, present, and future perspectives

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    From the devastating effects of the 1877–1879 Great Drought in the Northeast region to the creation of the Center for Weather Forecast and Climate Studies (CPTEC) at the National Institute for Space Research (INPE) in the early 1990 s, Brazil went from a total absence of meteorological expertise to becoming a member of a select group of nations with the infrastructure and technical expertise to build and run a global general circulation model. This article reviews the most critical moments in the development of climate services in Brazil, addressing the evolution of its infrastructure for observation, monitoring, modeling, and prediction, the still incipient efforts in systematically understanding users’ perspectives and needs, and the work required to incorporate the usable science and co-production paradigms into the main centers of production of climate information. Advances and challenges are analyzed, and actions for strengthening the climate services framework are proposed

    Integrating Phosphorylation Network with Transcriptional Network Reveals Novel Functional Relationships

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    Phosphorylation and transcriptional regulation events are critical for cells to transmit and respond to signals. In spite of its importance, systems-level strategies that couple these two networks have yet to be presented. Here we introduce a novel approach that integrates the physical and functional aspects of phosphorylation network together with the transcription network in S.cerevisiae, and demonstrate that different network motifs are involved in these networks, which should be considered in interpreting and integrating large scale datasets. Based on this understanding, we introduce a HeRS score (hetero-regulatory similarity score) to systematically characterize the functional relevance of kinase/phosphatase involvement with transcription factor, and present an algorithm that predicts hetero-regulatory modules. When extended to signaling network, this approach confirmed the structure and cross talk of MAPK pathways, inferred a novel functional transcription factor Sok2 in high osmolarity glycerol pathway, and explained the mechanism of reduced mating efficiency upon Fus3 deletion. This strategy is applicable to other organisms as large-scale datasets become available, providing a means to identify the functional relationships between kinases/phosphatases and transcription factors

    Analysis of Nursing Dissertations and Theses on Mental Health, Brazil, 1979-2007

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    This bibliographic study analyzes scientific texts published in the CEPEn database in the mental health field (1979-2007). A total of 280 abstracts were investigated, of which 208 were Master’s theses. The individuals investigated in these studies were professionals (57), patients (50), and professors and/or students (18). Among the themes addressed between 2000 and 2007 were the following: Nursing Care in Mental Health (40), Perception in Mental Health (37); and Transversality in Mental Health Care (27). This study provided an overview of the scientific research produced in the mental health field in Brazilian nursing graduate programs. We expect this study to elicit reflections concerning mental health care practice and enable new approaches for nursing promoting health and the prevention of diseases in order to enable patients to recover their citizenship, autonomy and quality of life.Se trata de un estudio bibliográfico, con el objetivo de analizar los textos científicos divulgados en la base de datos CEPEn en el área de salud mental (1979-2007). El total de resúmenes estudiados fueron 280, de los cuales 208 eran disertaciones de maestría. Los sujetos que se destacaron fueron los profesionales (57) y pacientes (50). Entre las temáticas abordadas se evidenciaron (2000-2007): el Cuidado de Enfermería en Salud Mental (40) y la Percepción en Salud Mental (37). Este trabajo posibilitó obtener una visión panorámica sobre la producción científica en salud mental en los cursos de Posgraduación en Enfermería en Brasil. Esperamos que el estudio incentive la reflexión sobre las prácticas de cuidado en salud mental y posibilite nuevos abordajes en enfermería con el objetivo de promover la salud y prevenir daños, de forma a favorecer la ciudadanía, la autonomía y la calidad de vida de los sujetos envueltos.Trata-se de estudo bibliográfico, com o objetivo de analisar os textos científicos, divulgados na base de dados CEPEn, na área de saúde mental (1979-2007). O total de resumos estudados foi 280, dos quais 208 constituíam-se de dissertações de mestrado. Os sujeitos que se destacaram foram os profissionais (57) e pacientes (50). Dentre as temáticas abordadas evidenciaram-se (2000-2007): o cuidado de enfermagem em saúde mental (40) e a percepção em saúde mental (37). Este trabalho possibilitou visualização panorâmica acerca da produção científica em saúde mental nos cursos de pós-graduação em enfermagem, no Brasil. Espera-se, aqui, que o estudo suscite reflexões acerca das práticas de cuidado em saúde mental e possibilite novas abordagens em enfermagem, com vistas à promoção da saúde e prevenção de agravos que favoreçam a cidadania, autonomia e qualidade de vida dos sujeitos envolvidos
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