533 research outputs found

    Alterations in vascular function in primary aldosteronism - a cardiovascular magnetic resonance imaging study

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    Introduction: Excess aldosterone is associated with increased cardiovascular risk. Aldosterone has a permissive effect on vascular fibrosis. Cardiovascular magnetic resonance imaging (CMR) allows study of vascular function by measuring aortic distensibility. We compared aortic distensibility in primary aldosteronism (PA), essential hypertension (EH) and normal controls and explored the relationship between aortic distensibility and pulse wave velocity (PWV).<p></p> Methods: We studied PA (n=14) and EH (n=33) subjects and age-matched healthy controls (n=17) with CMR, including measurement of aortic distensibility, and measured PWV using applanation tonometry. At recruitment, PA and EH patients had similar blood pressure and left ventricular mass.<p></p> Results: Subjects with PA had significantly lower aortic distensibilty and higher PWV compared to EH and healthy controls. These changes were independent of other factors associated with reduced aortic distensibility, including aging. There was a significant relationship between increasing aortic stiffness and age in keeping with physical and vascular aging. As expected, aortic distensibility and PWV were closely correlated.<p></p> Conclusion: These results demonstrate that PA patients display increased arterial stiffness compared to EH, independent of vascular aging. The implication is that aldosterone invokes functional impairment of arterial function. The long-term implications of arterial stiffening in aldosterone excess require further study.<p></p&gt

    A Higher-Order Logic for Concurrent Termination-Preserving Refinement

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    Compiler correctness proofs for higher-order concurrent languages are difficult: they involve establishing a termination-preserving refinement between a concurrent high-level source language and an implementation that uses low-level shared memory primitives. However, existing logics for proving concurrent refinement either neglect properties such as termination, or only handle first-order state. In this paper, we address these limitations by extending Iris, a recent higher-order concurrent separation logic, with support for reasoning about termination-preserving refinements. To demonstrate the power of these extensions, we prove the correctness of an efficient implementation of a higher-order, session-typed language. To our knowledge, this is the first program logic capable of giving a compiler correctness proof for such a language. The soundness of our extensions and our compiler correctness proof have been mechanized in Coq

    Inferring stabilizing mutations from protein phylogenies : application to influenza hemagglutinin

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    One selection pressure shaping sequence evolution is the requirement that a protein fold with sufficient stability to perform its biological functions. We present a conceptual framework that explains how this requirement causes the probability that a particular amino acid mutation is fixed during evolution to depend on its effect on protein stability. We mathematically formalize this framework to develop a Bayesian approach for inferring the stability effects of individual mutations from homologous protein sequences of known phylogeny. This approach is able to predict published experimentally measured mutational stability effects (ΔΔG values) with an accuracy that exceeds both a state-of-the-art physicochemical modeling program and the sequence-based consensus approach. As a further test, we use our phylogenetic inference approach to predict stabilizing mutations to influenza hemagglutinin. We introduce these mutations into a temperature-sensitive influenza virus with a defect in its hemagglutinin gene and experimentally demonstrate that some of the mutations allow the virus to grow at higher temperatures. Our work therefore describes a powerful new approach for predicting stabilizing mutations that can be successfully applied even to large, complex proteins such as hemagglutinin. This approach also makes a mathematical link between phylogenetics and experimentally measurable protein properties, potentially paving the way for more accurate analyses of molecular evolution

    A whey protein supplement decreases post-prandial glycemia

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    <p>Abstract</p> <p>Background</p> <p>Incidence of diabetes, obesity and insulin resistance are associated with high glycemic load diets. Identifying food components that decrease post-prandial glycemia may be beneficial for developing low glycemic foods and supplements. This study explores the glycemic impact of adding escalating doses of a glycemic index lowering peptide fraction (GILP) from whey to a glucose drink.</p> <p>Methods</p> <p>Ten healthy subjects (3M, 7F, 44.4 ± 9.3 years, BMI 33.6 ± 4.8 kg/m<sup>2</sup>) participated in an acute randomised controlled study. Zero, 5, 10 and 20 g of protein from GILP were added to a 50 g glucose drink. The control (0 g of GILP) meal was repeated 2 times. Capillary blood samples were taken fasting (0 min) and at 15, 30, 45, 60, 90 and 120 minutes after the start of the meal and analyzed for blood glucose concentration.</p> <p>Results</p> <p>Increasing doses of GILP decreased the incremental areas under the curve in a dose dependant manner (Pearson's r = 0.48, p = 0.002). The incremental areas (iAUC) under the glucose curve for the 0, 5, 10, and 20 g of protein from GILP were 231 ± 23, 212 ± 23, 196 ± 23, and 138 ± 13 mmol.min/L respectively. The iAUC of the 20 g GILP was significantly different from control, 5 g GILP and 10 g GILP (p < 0.001). Average reduction in the glucose iAUC was 4.6 ± 1.4 mmol.min/L per gram of ingested GILP.</p> <p>Conclusion</p> <p>Addition of GILP to a oral glucose bolus reduces blood glucose iAUC in a dose dependent manner and averages 4.6 ± 1.4 mmol.min/L per gram of GILP. These data are consistent with previous research on the effect of protein on the glycemic response of a meal.</p

    The stellar halo of the Galaxy

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    Stellar halos may hold some of the best preserved fossils of the formation history of galaxies. They are a natural product of the merging processes that probably take place during the assembly of a galaxy, and hence may well be the most ubiquitous component of galaxies, independently of their Hubble type. This review focuses on our current understanding of the spatial structure, the kinematics and chemistry of halo stars in the Milky Way. In recent years, we have experienced a change in paradigm thanks to the discovery of large amounts of substructure, especially in the outer halo. I discuss the implications of the currently available observational constraints and fold them into several possible formation scenarios. Unraveling the formation of the Galactic halo will be possible in the near future through a combination of large wide field photometric and spectroscopic surveys, and especially in the era of Gaia.Comment: 46 pages, 16 figures. References updated and some minor changes. Full-resolution version available at http://www.astro.rug.nl/~ahelmi/stellar-halo-review.pd

    Planck intermediate results. XLI. A map of lensing-induced B-modes

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    The secondary cosmic microwave background (CMB) BB-modes stem from the post-decoupling distortion of the polarization EE-modes due to the gravitational lensing effect of large-scale structures. These lensing-induced BB-modes constitute both a valuable probe of the dark matter distribution and an important contaminant for the extraction of the primary CMB BB-modes from inflation. Planck provides accurate nearly all-sky measurements of both the polarization EE-modes and the integrated mass distribution via the reconstruction of the CMB lensing potential. By combining these two data products, we have produced an all-sky template map of the lensing-induced BB-modes using a real-space algorithm that minimizes the impact of sky masks. The cross-correlation of this template with an observed (primordial and secondary) BB-mode map can be used to measure the lensing BB-mode power spectrum at multipoles up to 20002000. In particular, when cross-correlating with the BB-mode contribution directly derived from the Planck polarization maps, we obtain lensing-induced BB-mode power spectrum measurement at a significance level of 12 σ12\,\sigma, which agrees with the theoretical expectation derived from the Planck best-fit Λ\LambdaCDM model. This unique nearly all-sky secondary BB-mode template, which includes the lensing-induced information from intermediate to small (10≲ℓ≲100010\lesssim \ell\lesssim 1000) angular scales, is delivered as part of the Planck 2015 public data release. It will be particularly useful for experiments searching for primordial BB-modes, such as BICEP2/Keck Array or LiteBIRD, since it will enable an estimate to be made of the lensing-induced contribution to the measured total CMB BB-modes.Comment: 20 pages, 12 figures; Accepted for publication in A&A; The B-mode map is part of the PR2-2015 Cosmology Products; available as Lensing Products in the Planck Legacy Archive http://pla.esac.esa.int/pla/#cosmology; and described in the 'Explanatory Supplement' https://wiki.cosmos.esa.int/planckpla2015/index.php/Specially_processed_maps#2015_Lensing-induced_B-mode_ma

    Prácticas del enfermero en el contexto de la atención básica: scoping review

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    Objective: to identify and categorize the practices performed by nurses working in Primary Health Care and Family Health Strategy Units in light of responsibilities established by the profession’s legal and programmatic frameworks and by the Brazilian Unified Health System. Method: a scoping review was conducted in the following databases: LILACS, IBECS, BDENF, CINAHL and MEDLINE, and the Cochrane and SciELO libraries. Original research papers written by nurses addressing nursing practices in the primary health care context were included. Results: the review comprised 30 studies published between 2005 and 2014. Three categories emerged from the analysis: practices in the service; practices in the community; and management and education practices. Conclusion: the challenges faced by nurses are complex, as care should be centered on the population’s health needs, which requires actions at other levels of clinical and health responsibility. Brazilian nursing has achieved important advancements since the implementation of policies intended to reorganize work. There is, however, a need to shift work processes from being focused on individual procedures to being focused on patients so that an enlarged clinic is the ethical-political imperative guiding the organization of services and professional intervention.Objetivo: identificar e categorizar as práticas exercidas pelos enfermeiros junto às Unidades Básicas e às Equipes de Saúde da Família, à luz das atribuições previstas pelos marcos legais e programáticos da profissão e do Sistema Único de Saúde. Método: realizou-se uma revisão da literatura com o método scoping review, nas bases LILACS, IBECS, BDENF, CINAHL e MEDLINE, e nas bibliotecas Cochrane e SciELO. Incluíram-se artigos de pesquisa original, produzidos com enfermeiros, sobre as práticas de enfermagem no contexto dos cuidados de saúde primários. Resultados: a revisão abrangeu trinta estudos publicados entre 2005 e 2014. Da análise, resultaram três categorias: práticas no serviço, práticas na comunidade e práticas de gestão e formação. Conclusão: os desafios dos enfermeiros são complexos, posto que o cuidado deve estar centrado nas necessidades de saúde da população, o que remete à ação para outros níveis de responsabilidade clínica e sanitária. A enfermagem brasileira mostra importantes avanços desde a implantação das políticas de reorganização do trabalho. Necessita, entretanto, avançar no que se refere ao deslocamento dos processos de trabalho, focados em procedimentos individuais, para um processo mais voltado aos usuários, onde a clínica ampliada seja o imperativo ético-político da organização dos serviços e da intervenção profissional.Objetivo: identificar y categorizar las prácticas ejercidas por los enfermeros en las Unidades Básicas y los Equipos de Salud de la Familia, desde el punto de vista de las atribuciones previstas por los marcos legales y programáticos de la profesión y del Sistema Único de la Salud. Método: se realizó una revisión de la literatura con el método scoping review, en las bases LILACS, IBECS, BDENF, CINAHL y MEDLINE, y en las bibliotecas Cochrane y SciELO. Se incluyeron artículos de investigación original, producidos con enfermeros, sobre las prácticas de enfermería en el contexto de los cuidados de salud primarios. Resultados: la revisión abarcó treinta estudios publicados entre 2005 y 2014. Del análisis, resultaron tres categorías: prácticas en el servicio; prácticas en la comunidad; y, prácticas de administración y formación. Conclusión: los desafíos de los enfermeros son complejos, ya que el cuidado debe estar centrado en las necesidades de salud de la población, lo que conduce a la acción para otros niveles de responsabilidad clínica y sanitaria. La enfermería brasileña muestra importantes avances a partir de la implantación de las políticas de reorganización del trabajo. Necesita, entre tanto, avanzar en lo que se refiere al desplazamiento de los procesos de trabajo, enfocados en procedimientos individuales, para un proceso más dirigido a los usuarios, en donde la clínica ampliada sea el imperativo ético político de la organización de los servicios y de la intervención profesional.info:eu-repo/semantics/publishedVersio
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