680 research outputs found

    Esofagite Eosinofílica

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    A esofagite eosinofílica constitui uma doença infl amatória do esófago, mundialmente emergente, caracterizada pela infiltração significativa e isolada da mucosa esofágica por eosinófilos. A sintomatologia de apresentação revela-se bastante variável, mas frequentemente manifesta -se como uma doença de refluxo gastroesofágico que não responde à terapêutica anti-refluxo. O impacto alimentar esofágico e o desenvolvimento de estenoses esofágicas são complicações graves que podem ocorrer, com necessidade de remoção urgente do alimento e dilatação esofágica via endoscópica,respectivamente. A potencial gravidade destes sintomas justifica a importância do reconhecimento e do tratamento da doença, sobretudo tendo em conta que a sua prevalência tem vindo a aumentar na última década. A presente revisão sumariza o actual conhecimento sobre epidemiologia, apresentação clínica, possíveis mecanismos fisiopatológicos, história natural, abordagem diagnóstica e terapêutica desta condição

    The case for corporate responsibility: arguments from the literature.

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    Heightened scrutiny of organisations and ever increasing stakeholder demands for organisations to respond to issues within broader society, make it imperative that organisational leaders understand why they should undertake corporate responsibility initiatives. This literature review (part one of a two part study) investigates the issues that should be addressed by organisations under the banner of corporate responsibility, including the definition of corporate responsibility, its extent and boundaries and the business case for corporate responsibility. This background provides a basis for an exploratory study (part two) of how South African organisations should frame the case for corporate responsibility and how investment in this area can be assessed

    Nanoindentation of functionally graded hybrid polymer/metal thin films

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    Hybrid functionally graded coatings (2D-FGC) were deposited by magnetron co-sputtering from poly(tetrafluoroethylene) (PTFE) and AISI 316L stainless steel (316L) targets. The carbon and fluorine content varied from 7.3 to 23.7 at.% and from 0 to 57 at.%, respectively. The surface modification was developed to change the surface of 316L vascular stents in order to improve the biocompatibility of the outmost layer of the metallic biomaterial. In-depth XPS analysis revealed the presence of a graded chemical composition accompanied by the variation of the film structure. These results were complemented by those of transmission electron microscopy (TEM) analysis that highlighted the nanocomposite nature of the coatings. The nanomechanical characterization of 2D-FGC was performed by nanoindentation at several loads on the thin films deposited onto two different steel substrates: 316L and AISI M2. The study allowed establishing 0.7 mN as the load that characterized the coatings without substrate influence. Both hardness and Young modulus decrease with the increase of fluorine content due to the evolution in chemical composition, chemical bonds and structure

    The effect of flooding on the exchange of the volatile Câ‚‚-compounds ethanol, acetaldehyde and acetic acid between leaves of Amazonian floodplain tree species and the atmosphere

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    The effect of root inundation on the leaf emissions of ethanol, acetaldehyde and acetic acid in relation to assimilation and transpiration was investigated with 2–3 years old tree seedlings of four Amazonian floodplain species by applying dynamic cuvette systems under greenhouse conditions. Emissions were monitored over a period of several days of inundation using a combination of Proton Transfer Reaction Mass Spectrometry (PTR-MS) and conventional techniques (HPLC, ion chromatography). Under non-flooded conditions, none of the species exhibited measurable emissions of any of the compounds, but rather low deposition of acetaldehyde and acetic acid was observed instead. Tree species specific variations in deposition velocities were largely due to variations in stomatal conductance. Flooding of the roots resulted in leaf emissions of ethanol and acetaldehyde by all species, while emissions of acetic acid were only observed from the species exhibiting the highest ethanol and acetaldehyde emission rates. All three compounds showed a similar diurnal emission profile, each displaying an emission burst in the morning, followed by a decline in the evening. This concurrent behavior supports the conclusion, that all three compounds emitted by the leaves are derived from ethanol produced in the roots by alcoholic fermentation, transported to the leaves with the transpiration stream and finally partly converted to acetaldehyde and acetic acid by enzymatic processes. Co-emissions and peaking in the early morning suggest that root ethanol, after transportation with the transpiration stream to the leaves and enzymatic oxidation to acetaldehyde and acetate, is the metabolic precursor for all compounds emitted, though we can not totally exclude other production pathways. Emission rates substantially varied among tree species, with maxima differing by up to two orders of magnitude (25–1700 nmol m−2 min−1 for ethanol and 5–500 nmol m−2 min−1 for acetaldehyde). Acetic acid emissions reached 12 nmol m−2 min−1. The observed differences in emission rates between the tree species are discussed with respect to their root adaptive strategies to tolerate long term flooding, providing an indirect line of evidence that the root ethanol production is a major factor determining the foliar emissions. Species which develop morphological root structures allowing for enhanced root aeration produced less ethanol and showed much lower emissions compared to species which lack gas transporting systems, and respond to flooding with substantially enhanced fermentation rates and a non-trivial loss of carbon to the atmosphere. The pronounced differences in the relative emissions of ethanol to acetaldehyde and acetic acid between the tree species indicate that not only the ethanol production in the roots but also the metabolic conversion in the leaf is an important factor determining the release of these compounds to the atmosphere

    Technological innovations in biomedical training and practice

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    As we become more integrated into a global world, technological advances and teaching innovation that are grounded in Science have become crucial. Rapid advancements in science education and information technology provide promising resources that require many academic disciplines to work together. Developing new tools and defining new methodologies to share educational experiences, including empirical studies that support their efficiency, constitute a promising approach to improve Health Sciences. The aim of this session is to encourage and enable the exchange of information related with the advance and support of Health Science Education. In this paper the authors summarize the recent advances in technological innovations in biomedical training and practice. Most of the main trends in this field are reviewed, including: training in health sciences through a variety of resources such as computer simulations, stereoscopic visualization systems with augmented reality glasses, computer platforms for managing and using resources and documents; the generation of three-dimensional images developed with commercial software for 3D reconstruction; medical and surgical simulation using Virtual Reality (RV) and Augmented Reality (AR); the role of stereoscopic vision systems in the health sciences; and the use of teaching medical material reconstructed with 3D printers.info:eu-repo/semantics/publishedVersio

    New technologies in health education and research

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    The studies in this track provided an updated overview of different technological innovation procedures in distinct health science fields. Thus, technological applications from medical imaging treatment and three-dimensional visualization to simulation systems useful in clinical practice training (simulations with mannequins, training with manual control devices, virtual reality techniques with stereo vision helmets, amongst others) are presented. The main objective of these procedures is to improve the quality of university teaching and continuing education, using the latest resources, which are starting to be implemented in different universities.info:eu-repo/semantics/publishedVersio

    Experimental study on the mechanical performance of steel ties for brick masonry veneers

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    Publicado em "Brick and block masonry: trends, innovations and challenges. ISBN 978-1-138-02999-6An experimental study was carried out to analyse the tension and compression behaviour of wall ties anchoring brick veneer walls to masonry infill walls as the backing support. Connection subassemblies were tested under monotonic and cyclic loading, simulating out-of-plane loading of veneer wall systems in order to understand the influence of six different ties with different design, thickness and attachment methods in the strength, stiffness and failure modes of the connection system. Experimental results from this study show more details about the behaviour of this system and importance of determined parameters. Tensile resistance capacity can be more influenced by wall tie design, while tie thickness was considered to be the most important parameter in compression behaviour. Attachment methods studied do not considered a very influential factor. This study can help to understand and justify the contribution of these elements for the mechanical masonry veneer walls under different loading conditions.Portuguese Science and Technology Foundation (FCT) - grant SFRH/BD/96484/2013FCT (Portuguese Foundation for Science and Technology), within ISISE, project UID/ECI/04029/201

    Silvicultura urbana em municípios brasileiros e]com maior concentração populacional.

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    A boa gestão da arborização urbana é um dos principais requisitos para propiciar qualidade de vida à população. Para o manejo e planejamento da silvicultura urbana é importante um diagnóstico detalhado. O diagnóstico da silvicultura urbana é obtido principalmente por inventário arbóreo e serve como subsídio para o planejamento urbano. As cidades brasileiras tem estrutura precária de gerenciamento da arborização e não há um plano nacional de inventário urbano. Objetivou-se identificar dentre os municípios mais populosos do Brasil, aqueles que contam com inventários e manejo da silvicultura urbana para futuras políticas públicas da área
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