49 research outputs found

    Thermal, mechanical and chemical analysis of poly(vinyl alcohol) multifilament and braided yarns

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    Poly(vinyl alcohol) (PVA) in multifilament and braided yarns (BY) forms presents great potential for the design of numerous applications. However, such solutions fail to accomplish their requirements if the chemical and thermomechanical behaviour is not sufficiently known. Hence, a comprehensive characterisation of PVA multifilament and three BY architectures (6, 8, and 10 yarns) was performed involving the application of several techniques to evaluate the morphological, chem- ical, thermal, and mechanical features of those structures. Scanning electron microscopy (SEM) was used to reveal structural and morphological information. Differential thermal analysis (DTA) pointed out the glass transition temperature of PVA at 76 °C and the corresponding crystalline melt- ing point at 210 °C. PVA BY exhibited higher tensile strength under monotonic quasi-static loading in comparison to their multifilament forms. Creep tests demonstrated that 6BY structures present the most deformable behaviour, while 8BY structures are the least deformable. Relaxation tests showed that 8BY architecture presents a more expressive variation of tensile stress, while 10BY of- fered the least. Dynamic mechanical analysis (DMA) revealed storage and loss moduli curves with similar transition peaks for the tested structures, except for the 10BY. Storage modulus is always four to six times higher than the loss modulus.This work was funded by European Regional Development funds (FEDER) through the Competitiveness and Internationalization Operational Program (POCI)—COMPETE andby Na-tional Funds through Portuguese Fundação para a Ciência e Tecnologia (FCT) under the project UID/EMS/50022/2020, UID/EEA/04436/2019 andUID/ CTM/00264/2019. Andrea Zille acknowledges financial support of the FCT through the project PTDC/CTM-TEX/28295/2017,and Nuno Dourado acknowledges financial support of the FCT through the project PTDC/EME-SIS/28225/2017. M.F.S.M. de Moura acknowledges the ‘Laboratório Associado de Energia, Transportes e Aeronáutica’ (LAETA) for the financial support

    CHADS2 and CHA2DS2VASc scores as predictors of cardioembolic sources in secondary stroke prevention

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    Introdução e objetivos: A cardioembolia representa uma das causas mais frequentes de lesões cerebrovasculares isquémicas, com prevalência estimada de 20-30% e implicações terapêuticas diretas que obrigam à sua correta avaliac¸ão. Apesar de a validação das escalas de risco cardioembólico (CHADS2 e, mais recentemente, CHA2DS2-VASc) em populações heterogéneas de doentes com fibrilhac¸ão furicular, desconhece-se ainda a sua validade em contexto de prevenc¸ão secundária cerebrovascular. É objetivo deste trabalho estudar a sensibilidade e especificidade diferencial das escalas de risco cardioembólico como preditoras de fonte cardioembólica documentada por ecocardiograma transesofágico (ETE) numa população de doentes com AVC isquémico. Métodos: Aplicámos as escalas CHADS2 e CHA2DS2-VASc a todos os doentes internados por evento cerebrovascular isquémico na Unidade de AVC/Enfermaria de Neurologia de um hospital central português com diagnóstico de fibrilhação auricular (prévio ou obtido durante/após o internamento), que realizaram ETE entre janeiro e agosto de 2011. Definimos como presença de fonte cardioembólica a observação em ETE de autocontraste espontâneo na aurícula e apêndice auricular esquerdo ou trombos nas cavidades cardíacas esquerdas. Resultados: Analisámos 94 doentes, 66,0% do sexo masculino, idade média: 64,4 anos (desvio padrão: 14,2). Foi detetada fonte cardioembólica em 20 doentes. A análise de curva Receiver Operating Characteristic (ROC) identifica como preditores de fonte cardioembólica pontuação CHADS2 ≥ 4; sensibilidade: 75,0%, especificidade: 66,0%, p = 0,014 e pontuac¸ão CHA2DS2-VASc ≥ 5; sensibilidade: 83,3%, especificidade: 58,0%, p = 0,009.Introduction and objectives: Cardioembolism is one of the most common causes of ischemic stroke, with an estimated prevalence of 20-30%, and correct diagnosis is essential given the therapeutic implications. Although stroke risk scores (CHADS2 and more recently CHA2DS2- VASc) have been validated in heterogeneous populations of patients with atrial fibrillation, their accuracy has not been ascertained for secondary stroke prevention. We set out to assess the sensitivity and specificity of the CHADS2 and CHA2DS2-VASc stroke risk scores as predictors of cardioembolic sources, documented by transesophageal echocardiography (TEE) in a population with ischemic stroke. Methods: The CHADS2 and CHA2DS2-VASc scores were applied to all patients admitted to the stroke unit/neurology ward of a Portuguese tertiary hospital with atrial fibrillation (diagnosed previously or during or after admission) who underwent TEE between January and August 2011. The presence of a cardioembolic source was defined as the observation by TEE of spontaneous echo contrast in the left atrium and atrial appendage or thrombi in the left cardiac chambers. Results: We studied 94 patients, 66.0% male, mean age 64.4 years (standard deviation 14.2). A cardioembolic source was detected in 20 patients. ROC curve analysis identified as predictors of cardioembolic source CHADS2 score ≥4 (sensitivity of 75.0%, specificity of 66.0%, p=0.014) and CHA2DS2-VASc score ≥5 (sensitivity of 83.3%, specificity of 58.0%, p=0.009). Conclusions: Both scores showed acceptable sensitivity as predictors of embolic risk in the context of secondary prevention of cardioembolic stroke. The CHA2DS2-VASc score has higher sensitivity than CHADS2 but lower specificity

    Effect of dietary palm oil on growth and carcass composition of Heterobranchus longifilis fingerlings

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    This study investigated the effects of dietary palm oil (PO) on growth performance and carcass composition of Heterobranchus longifilis with the goal of replacing dietary fish oil with palm oil. In this study triplicate groups of H. longifilis fingerlings were fed the experimental diets for 8 weeks. Five isonitrogenous (45% crude protein), isoenergetic (20 KJg-1) experimental diets were made containing either 6.0% FO and 0% PO, 4.5% FO and 1.5% PO; 3.0% FO and 3.0% PO; 1.5% FO and 4.5% PO; or 0% FO and 6.0% PO using soybean and fish meal as the protein source. Dietary palm oil had no significant effect on growth rate or feed conversion ratio. Similarly, No significant differences were observed between dietary treatments for moisture, protein and ash content in H. longifilis fingerlings. However, fillet saturated, monounsaturated fatty acids and liver lipid deposition were significantly (P0.05) higher in fish fed 6.0% PO diet. This study suggests that the replacement of cod liver oil by palm oil as lipid supplement in the diet permitted a clear improvement of growth and FCR of H. longifilis. This indicates that PO can effectively replace FO in the diet of the fish without compromising fish growth and feed efficiency

    Pervasive gaps in Amazonian ecological research

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    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

    Pervasive gaps in Amazonian ecological research

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    Transtorno bipolar em crianças: análise de relato de caso 2018-2023

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    O transtorno bipolar em crianças é uma realidade clínica que demanda atenção especializada. A compreensão dos sintomas, fatores de risco, prevalência e desafios diagnósticos é fundamental para proporcionar intervenções precoces e adequadas, visando melhorar a qualidade de vida desses jovens e reduzir o impacto a longo prazo dessa condição psiquiátrica. Trata-se de um estudo cujo objetivo foi objetivo revisar relatos de caso publicados entre 2018 e 2023 sobre transtorno bipolar em crianças, identificando o estado da arte desses estudos. Para isso, se realizou uma revisão sistemática de literatura utilizando as bases de dados Medical Literature Analysis and Retrieval System Online (MEDLINE), Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS) e Scientific Electronic Library Online (SCIELO). Com a análise e interpretação qualitativa dos resultados, a principal conclusão deste estudo é que o transtorno bipolar na infância é uma condição complexa, manifestando-se com comportamentos consistentes com o Transtorno de Conduta e sendo influenciado por fatores ambientais, familiares e genéticos. O tratamento eficaz requer uma abordagem multidisciplinar, integrando intervenções farmacológicas e não farmacológicas, personalizadas conforme as necessidades individuais. A supervisão familiar é crucial para a adesão ao tratamento, mas reconhece-se a necessidade contínua de pesquisa para aprimorar as estratégias terapêuticas diante da diversidade de casos

    Educomunicação e suas áreas de intervenção: Novos paradigmas para o diálogo intercultural

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    oai:omp.abpeducom.org.br:publicationFormat/1O material aqui divulgado representa, em essência, a contribuição do VII Encontro Brasileiro de Educomunicação ao V Global MIL Week, da UNESCO, ocorrido na ECA/USP, entre 3 e 5 de novembro de 2016. Estamos diante de um conjunto de 104 papers executivos, com uma média de entre 7 e 10 páginas, cada um. Com este rico e abundante material, chegamos ao sétimo e-book publicado pela ABPEducom, em seus seis primeiros anos de existência. A especificidade desta obra é a de trazer as “Áreas de Intervenção” do campo da Educomunicação, colocando-as a serviço de uma meta essencial ao agir educomunicativo: o diálogo intercultural, trabalhado na linha do tema geral do evento internacional: Media and Information Literacy: New Paradigms for Intercultural Dialogue

    Pervasive gaps in Amazonian ecological research

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    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost
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