1,720,967 research outputs found

    Platelet activation, inflammatory mediators and hypercholesterolemia.

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    Atherogenic cofactors, such as altered cholesterol metabolism, may impact locally on inflammatory responses in atherosclerotic lesions. Blood levels of inflammatory markers (e.g., C-reactive protein, fibrinogen) have been associated with hypercholesterolemia and with overt atherothrombotic disorders. More recently. cytokines (e.g., interleukin-6, interleukin-1beta) and soluble adhesion molecules (e.g., selectins, intercellular adhesion molecule-1, vascular cell adhesion molecule-1) have been associated with both hypercholesterolemia and atherosclerotic disease, suggesting their use as potential therapeutic targets for the non-specific "anti-inflammatory" treatment of atherosclerosis. The inflammatory response associated with hypercholesterolemia involves not only the intrinsic cells of the artery wall. but also circulating cells. Platelets participate in this disease process through the release of a wide variety of biologically active substances. An imbalance of the hemostatic system and persistent in vivo platelet activation can be observed in hypercholesterolemia and may have pathophysiological implications in the development and progression of atherosclerotic plaques. Recent findings on the inflammatory actions of platelets have established the potential for a previously unrecognized biologic role for platelets in inflammation and vascular injury, and have opened new perspectives in the comprehension of the pathogenetic mechanism(s) of atherosclerosis. Stimulated platelets actively synthesize proinflammatory cytokines (e.g., CD40L, IL-1beta) and are able to release chemokines (i.e., platelet factor-4, RANTES) which have been all involved in the inflammatory process associated with hypercholesterolemia. This review will summarize the present understanding of the interplay between hypercholesterolemia, inflammation and platelet activation in the development and progression of atherosclerosis, and we also discuss the effects of lipid-lowering treatment on these phenomena

    Oxidant stress and platelet activation in hypercholesterolemia

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    Hypercholesterolemia is the dominant risk factor associated with atherothrombotic disorders in the western world. Consequently, much attention has been devoted to defining its role in the pathogenesis of atherosclerosis. It is currently recognized that hypercholesterolemia induces phenotypic changes in the microcirculation that are consistent with oxidative and nitrosative stresses. Superoxide is generated via several cellular systems and, once formed, participates in a number of reactions, yielding various free radicals, such as hydrogen peroxide, peroxynitrite, or oxidized low-density lipoproteins. Once oxidant stress is invoked, characteristic pathophysiologic features ensue, such as platelet activation and lipid peroxidation, which are both involved in the initiation and progression of the atherosclerotic lesions. Thus, therapeutic strategies that act to maintain the normal balance in the oxidant status of the vascular bed may prove effective in reducing the deleterious consequences of hypercholesterolemia

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed

    Variations on the Author

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    “Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship

    Appropriate Similarity Measures for Author Cocitation Analysis

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    We provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis

    Dispelling the Myths Behind First-author Citation Counts

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    We conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more sophisticated methods

    Author Index

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    koamabayili/VECTRON-author-checklist: VECTRON author checklist

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    We have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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