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The left internal mammary artery implant combined with epicardiectomy and free omental graft provides three extra-coronary sources of blood. This operation tested in dogs with 92% main-stem occlusion of three coronary arteries protected 75% of the animals. Applied clinically in over 100 patients, the operation resulted in 90% improvement. To obtain complete myocardial revascularization, the right internal mammary artery has been used as a fourth source of extra-coronary blood. In 57 animals, the right internal mammary arteries were implanted into the anterior walls of the right ventricle; in 80% this vessel formed anastomoses with the right coronary tree, and in 65% with the right and left coronary arteriolar systems. Six patients are described who underwent right internal mammary artery implantation; five of these in addition had the combined operation of left internal mammary artery implant, epicardiectomy and free omental graft. All patients had completely blocked right coronary arteries; in addition, five had advanced disease of the left coronary arterial tree. 相似文献
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Benjamin Owen Nicholas Bojdo Andrey Jivkov Bernard Keavney Alistair Revell 《Biomechanics and modeling in mechanobiology》2018,17(5):1217-1242
Computational modelling of the cardiovascular system offers much promise, but represents a truly interdisciplinary challenge, requiring knowledge of physiology, mechanics of materials, fluid dynamics and biochemistry. This paper aims to provide a summary of the recent advances in cardiovascular structural modelling, including the numerical methods, main constitutive models and modelling procedures developed to represent cardiovascular structures and pathologies across a broad range of length and timescales; serving as an accessible point of reference to newcomers to the field. The class of so-called hyperelastic materials provides the theoretical foundation for the modelling of how these materials deform under load, and so an overview of these models is provided; comparing classical to application-specific phenomenological models. The physiology is split into components and pathologies of the cardiovascular system and linked back to constitutive modelling developments, identifying current state of the art in modelling procedures from both clinical and engineering sources. Models which have originally been derived for one application and scale are shown to be used for an increasing range and for similar applications. The trend for such approaches is discussed in the context of increasing availability of high performance computing resources, where in some cases computer hardware can impact the choice of modelling approach used. 相似文献
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Coral Reefs - Associations between resembling species have been noted long ago by naturalists and have been traditionally interpreted in terms of mimicry, whereby a mimetic species is naturally... 相似文献
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Benjamin T. Hutchins 《Biodiversity and Conservation》2018,27(2):475-501
Biodiversity conservation requires an objective and consistent method for evaluating the conservation status of species. Conservation status assessments can identify conservation priorities and can highlight data gaps, effective conservation strategies, and groups of taxa that are underrepresented in conservation efforts relative to charismatic flagship and umbrella species. Groundwater invertebrates have a suite of traits that make them inherently vulnerable. But they go largely unnoticed by the general public and conservation practitioners, and comprehensive conservation status assessments are lacking for most species. In this article, the conservation status of all sixty-nine described groundwater-obligate invertebrates recorded from Texas, U.S.A. was assessed using NatureServe methodology. Some of the smallest taxa (e.g. copepods, ostracods, and mites) are too poorly known to evaluate their conservation status. Species restricted to springs were generally more at risk than species in other groundwater habitats, and beetles and snails were the most imperiled taxonomic groups. Most species faced low or medium severity threats, and only seven percent faced high or very high magnitude threats. Threat level varied among aquifers and among sites within aquifers and was primarily dependent on human population density and the adequacy of regulatory mechanisms protecting groundwater quality and quantity. Regardless of threat severity, fifty-five percent of evaluated species were ranked as imperiled or critically imperiled, largely due to extreme small-range endemism. Relative to other regions, Texas’ groundwater fauna is not unique in terms of rarity and threat, suggesting that as an ecological group, groundwater-obligate species are probably among the world’s most imperiled taxa. 相似文献
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Matthew Calamia Benjamin D. Hill Mandi W. Musso Russell D. Pella Wm. Drew Gouvier 《Attention deficit and hyperactivity disorders》2018,10(3):177-188
The objective of this study was to assess the factor structure and clinical correlates of a 61-item version of the Wender Utah Rating Scale (WURS), a self-report retrospective measure of childhood problems, experiences, and behavior used in ADHD assessment. Given the currently mostly widely used form of the WURS was derived via a criterion-keyed approach, the study aimed to use latent variable modeling of the 61-item WURS to potentially identify more and more homogeneous set of items reflecting current conceptualizations of ADHD symptoms. Exploratory structural equation modeling was used to generate factor scores which were then correlated with neuropsychological measures of intelligence and executive attention as well as a broad measure of personality and emotional functioning. Support for a modified five-factor model was found: ADHD, disruptive mood and behavior, negative affectivity, social confidence, and academic problems. The ADHD factor differed somewhat from the traditional 25-item WURS short form largely through weaker associations with several measures of personality and psychopathology. This study identified a factor more aligned with DSM-5 conceptualization of ADHD as well as measures of other types of childhood characteristics and symptoms which may prove useful for both research and clinical practice. 相似文献