105 research outputs found

    Isothermal omega assisted alpha phase precipitation and microstructural evolution of an aged Ti-30Nb-3Fe alloy

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    The mechanical behavior of metastable ÎČ Ti alloys can be controlled through heat treatments. Thus, the relationship between the precipitation of α phase and the mechanical properties of these alloys is of special interest. In this work, the microstructure evolution of Ti-30Nb-3Fe alloy during aging heat treatments was evaluated using optical microscopy, scanning electron microscopy and X-ray diffraction. Moreover, Vickers hardness and elastic modulus were measured as a function of aging time. Finally, the ultimate strength and ductility of the alloy aged at 500 °C was assessed by tensile tests. In comparison to a Ti-30Nb alloy, the addition of Fe lowered the ÎČ-transus temperature, decreased the martensite start temperature to a value below room temperature, increased the precipitation temperature and reduced the dissolution temperature of ω phase, and lastly, decreased the α phase precipitation temperature. Low heating rates enabled isothermal ω phase precipitation and growth, providing favorable conditions for α phase precipitation and increasing the amount of α phase precipitates. Compared to the solution heat-treated and water-quenched condition, aging heat-treated Ti-30Nb-3Fe alloy presented higher Vickers hardness and mechanical strength, without significant loss of ductility233CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP405054/2016-588887.357955/2019-002016/24693-3The authors gratefully acknowledge the LNNano (National Nanotechnology Laboratory) at the CNPEM (National Center for Research on Energy and Materials) for allowing access to its SEM facilities. We also acknowledge the financial support of the Brazilian research funding agencies FAPESP (State of SĂŁo Paulo Research Foundation) for Grant #2016/24693-3, CNPq (National Council for Scientific and Technological Development) for Grant #405054/2016-5, and CAPES/PNPD (Coordination for the Improvement of Higher Education Personnel) for Grant #88887.357955/2019-00. We thank the Brazilian Niobium Mining and Processing Company CBMM for supplying the Nb used in this stud

    Association between Metabolic Disorders and Cholangiocarcinoma: Impact of a Postulated Risk Factor with Rising Incidence

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    Introduction and objectives: The incidence of cholangiocarcinoma (CCA) has been increasing globally. Although a concomitant increase in the incidence of metabolic disorders might suggest a causal relationship, the data are scarce. We aimed to describe the prevalence of metabolic disorders in patients with CCA and report the clinical features and outcomes. Patients and Methods: Retrospective study including patients with CCA. Patients were divided into: (1) past history of diabetes or/and overweight/obesity (“metabolic disorder group”) and (2) without any of these features (“non-metabolic-disorder group”). A Cox regression model was used to determine the prognostic factors. Results: 122 patients were included. In total, 36 (29.5%) had overweight/obesity, 24 (19.7%) had diabetes, and 8 (6.6%) had both. A total of 29 (23.8%) patients had resectable disease and received upfront surgery. A total of 104 (85.2%) received chemotherapy for advanced/recurrent disease. The overall survival of the cohort was 14.3 months (95% CI: 10.1–17.3). ECOG-PS 0 (p < 0.0001), resectable disease (p = 0.018) and absence of vascular invasion (p = 0.048) were independently associated with better prognosis. The “metabolic disorder group” (n = 52) had a median survival of 15.5 months (95% CI 10.9–33.9) vs. 11.5 months (95% CI 8.4–16.5) in the “non-metabolic-disorder group” (n = 70) (HR: 1.10; 95% CI 0.62–1.94). Patients with resectable disease in the “metabolic group” had longer survival than patients in the “non-metabolic group” (43.4 months (95% CI 33.9-NR) vs. 21.8 months (95% CI 8.6–26.9); HR = 0.12, 95% CI 0.03–0.59). Conclusion: Metabolic disorders are frequent among CCA patients. Underlying metabolic comorbidities may be associated with prognosis in resectable CCA. There is a need to explore the mechanism that drives CCA carcinogenesis in a metabolic background

    Direito, emancipação e cidadania: a experiĂȘncia do projeto Promotoras Legais Populares no embate à violĂȘncia contra a mulher e na transformação de realidades

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    O artigo fala sobre o Projeto de ExtensĂŁo Promotoras Legais Populares, grupo que debate e discute temas relacionados ao direito, à discriminação de gĂȘnero, cidadania etc. O objetivo primordial do grupo Ă© fornecer às mulheres ”“ de diferentes contextos socioculturais ”“maior conhecimento e maior senso crĂ­tico sobre seus direitos, que sĂŁo constantemente sobrepostos e esquecidos dentro de uma sociedade machista. O projeto se funda, principalmente, em trĂȘs bases teĂłricas: na visĂŁo mais ampliada do direito, na educação jurĂ­dica popular e nas açÔes afirmativas em gĂȘnero

    O comportamento do consumidor de vinho no mercado portuguĂȘs

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    A presente investigação resultou da necessidade de perceber as razĂ”es que motivam e que eventualmente poderĂŁo condicionar a frequĂȘncia de consumo de vinho em Portugal. Deste modo, o principal objetivo deste trabalho Ă© compreender as motivaçÔes de compra e consumo, dependendo da situação de uso e de caraterĂ­sticas pessoais. A literatura existente sobre as motivaçÔes de consumo de vinho salienta a existĂȘncia de efeitos diretos sobre as motivaçÔes do gĂ©nero do comprador e da ocasiĂŁo de consumo. Este estudo introduz uma formulação alternativa destes efeitos, considerando-os indiretos, i.e. completamente mediados pelo conhecimento subjetivo do comprador e pelas emoçÔes que ele associa ao respetivo consumo. Foram desenvolvidos dois modelos, um para explicar as motivaçÔes, outro a frequĂȘncia de consumo, os quais foram posteriormente validados numa amostra de 523 compradores entrevistados no momento da compra em grandes superfĂ­cies retalhistas da Grande Lisboa e do Grande Porto. Os resultados apresentados no primeiro modelo apontam para a rejeição dos efeitos diretos, sendo o conhecimento subjetivo o mediador mais importante. Sugere-se que a autoconfiança e a eficĂĄcia na decisĂŁo, que aparecem associadas ao conhecimento subjetivo, justifiquem que os homens se sintam mais motivados para o consumo. Este efeito positivo do conhecimento na motivação Ă© ainda mais importante nas ocasiĂ”es regulares. No segundo modelo, verificou-se que a frequĂȘncia de consumo Ă© explicada predominantemente pela motivação por gratificação sensorial e, tambĂ©m, pela ocasiĂŁo de consumo no contexto de refeição normal (efetuada no dia-a-dia). O conhecimento subjetivo revelou-se tambĂ©m como elemento fundamental no comportamento do consumidor, quer pela sua influĂȘncia sobre as motivaçÔes, quer pela sua influĂȘncia sobre a frequĂȘncia de consumo. As conclusĂ”es retiradas desta investigação salientam a importĂąncia do conhecimento subjetivo no consumo de vinho. Realçam tambĂ©m que os efeitos de fatores como o gĂ©nero e a ocasiĂŁo sobre as motivaçÔes para consumir vinho, reportados na literatura, poderĂŁo dever-se a mediadores de ordem psicogrĂĄfica, como o conhecimento subjetivo. Esta conclusĂŁo tem implicaçÔes no marketing de vinhos para compradores regulares, nomeadamente pelo reconhecimento da necessidade de reforçar a perceção de confiança e de eficĂĄcia de decisĂŁo que costumam ser associadas aos elevados nĂ­veis de conhecimento percebido numa categoria de produto

    AlteraçÔes comportamentais em crianças portadoras de enfermidades crĂŽnicas e suas repercussĂ”es na famĂ­lia: Hospital da Criança – Obras Sociais de IrmĂŁ Dulce, Salvador, BA

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    It is a pilot study, involving 15 children that were commited at the Hospital da Criança: Obras Sociais de IrmĂŁ Dulce, Salvador, Bahia. The objective of this study is the investigation of family’s perception about the pediatric patient with chronic illness. The responsible for the patient answered a questionnaire that approached subjects regarding the partner demographic profile, family  knowledge degree about the disease, behavior alterations in child and its family, besides the impression of prognostic and  the medical services that were offered to the researched population. The results evidenced that some kind of behavior alteration were presented by all evaluated population, being more frequent symptoms of: sadness; anxiety; isolation and sleepness. The parents referred that after the appearance of the disease, the more common manifestations were: increase of the familiar union, feeling of fear, anxiety and concern with physical sequels. Regarding the model of hospital care, it was revealed that they were satisfied with the quality and efficiency of the medical service. However, they consider insufficient the psychological support to the child and the family throughout the confrontation of the chronic disease. The next phase of this study should make possible a more consistent and inclusive analysis concerning the proposed theme.Trata-se de um estudo piloto que envolve 15 crianças internadas no Hospital da Criança: Obras Sociais de IrmĂŁ Dulce, Salvador, Bahia, realizado com o objetivo de investigar a percepção da famĂ­lia perante o paciente pediĂĄtrico, portador de enfermidade crĂŽnica. Para tanto, o responsĂĄvel pelo paciente respondeu a um questionĂĄrio que abordou questĂ”es referentes a perfil sociodemogrĂĄfico, grau de conhecimento da famĂ­lia em relação Ă  doença, percepção quanto a alteraçÔes comportamentais ocorridas na criança e na famĂ­lia, alĂ©m da impressĂŁo quanto ao prognĂłstico e serviços mĂ©dicos prestados Ă  população pesquisada. Os resultados desta pesquisa evidenciaram que toda a população avaliada apresentou algum tipo de alteração comportamental, sendo mais freqĂŒentes os sintomas: tristeza, ansiedade, isolamento e sonolĂȘncia. Os pais referiram como manifestaçÔes mais comuns, apĂłs o surgimento da doença: maior uniĂŁo familiar, sentimento de medo, ansiedade e preocupação com seqĂŒelas fĂ­sicas. No que diz respeito ao padrĂŁo de assistĂȘncia hospitalar, revelaram-se satisfeitos com a qualidade e eficiĂȘncia do serviço mĂ©dico prestado. Entretanto, consideram insuficiente o suporte psicolĂłgico Ă  criança e Ă  famĂ­lia no enfrentamento da doença crĂŽnica. A prĂłxima fase deste estudo deverĂĄ possibilitar uma anĂĄlise mais consistente e abrangente acerca do tema proposto

    Effects of Temperature, Salinity and Fish in Structuring the Macroinvertebrate Community in Shallow Lakes: Implications for Effects of Climate Change

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    Climate warming may lead to changes in the trophic structure and diversity of shallow lakes as a combined effect of increased temperature and salinity and likely increased strength of trophic interactions. We investigated the potential effects of temperature, salinity and fish on the plant-associated macroinvertebrate community by introducing artificial plants in eight comparable shallow brackish lakes located in two climatic regions of contrasting temperature: cold-temperate and Mediterranean. In both regions, lakes covered a salinity gradient from freshwater to oligohaline waters. We undertook day and night-time sampling of macroinvertebrates associated with the artificial plants and fish and free-swimming macroinvertebrate predators within artificial plants and in pelagic areas. Our results showed marked differences in the trophic structure between cold and warm shallow lakes. Plant-associated macroinvertebrates and free-swimming macroinvertebrate predators were more abundant and the communities richer in species in the cold compared to the warm climate, most probably as a result of differences in fish predation pressure. Submerged plants in warm brackish lakes did not seem to counteract the effect of fish predation on macroinvertebrates to the same extent as in temperate freshwater lakes, since small fish were abundant and tended to aggregate within the macrophytes. The richness and abundance of most plant-associated macroinvertebrate taxa decreased with salinity. Despite the lower densities of plant-associated macroinvertebrates in the Mediterranean lakes, periphyton biomass was lower than in cold temperate systems, a fact that was mainly attributed to grazing and disturbance by fish. Our results suggest that, if the current process of warming entails higher chances of shallow lakes becoming warmer and more saline, climatic change may result in a decrease in macroinvertebrate species richness and abundance in shallow lakes

    EpIG‐DB: A database of vascular epiphyte assemblages in the Neotropics

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    Vascular epiphytes are a diverse and conspicuous component of biodiversity in tropical and subtropical forests. Yet, the patterns and drivers of epiphyte assemblages are poorly studied in comparison with soil‐rooted plants. Current knowledge about diversity patterns of epiphytes mainly stems from local studies or floristic inventories, but this information has not yet been integrated to allow a better understanding of large‐scale distribution patterns. EpIG‐DB, the first database on epiphyte assemblages at the continental scale, resulted from an exhaustive compilation of published and unpublished inventory data from the Neotropics. The current version of EpIG‐DB consists of 463,196 individual epiphytes from 3,005 species, which were collected from a total of 18,148 relevĂ©s (host trees and ‘understory’ plots). EpIG‐DB reports the occurrence of ‘true’ epiphytes, hemiepiphytes and nomadic vines, including information on their cover, abundance, frequency and biomass. Most records (97%) correspond to sampled host trees, 76% of them aggregated in forest plots. The data is stored in a TURBOVEG database using the most up‐to‐date checklist of vascular epiphytes. A total of 18 additional fields were created for the standardization of associated data commonly used in epiphyte ecology (e.g. by considering different sampling methods). EpIG‐DB currently covers six major biomes across the whole latitudinal range of epiphytes in the Neotropics but welcomes data globally. This novel database provides, for the first time, unique biodiversity data on epiphytes for the Neotropics and unified guidelines for future collection of epiphyte data. EpIG‐DB will allow exploration of new ways to study the community ecology and biogeography of vascular epiphytes
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