1,721,356 research outputs found

    Retrievable vena cava filters: Key considerations

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    Retrievable filters are a new generation of inferior vena cava (IVC) filters and represent an attractive option because they may be either left in place permanently or safety retrieved after a quite long period when they become unnecessary. In this review the currently available literature regarding retrievable IVC filters is summarized and their efficacy and safety is discussed. Moreover, the appropriate indications for their use are reviewed. Retrievable filters are becoming safer and easier to use; in fact the bioengineering research has optimized the technical characteristics of these devices, in order to reduce the incidence of possible complications. However, there are important unresolved issues, including the appropriate maximum implantation time, the possibility to safety and efficaciously remove the filters without being compromised by entrapped clots, and the use of anticoagulation during the implantation and periremoval periods. Large prospective cohort studies or randomized trials are strongly warranted to definitely clarify the beneficial rote of these devices. (C) 2007 Elsevier Ltd. All rights reserved

    Behçet: the syndrome

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    Behçet's syndrome (BS) is a systemic vasculitis characterized by a relapsing and remitting course. It can involve the skin, mucosa, joints, vessels (arteries and/or veins), eyes, and nervous and gastrointestinal systems, and so is referred to as a syndrome rather than as a unique and nosologically distinct condition. These involvements may present alone or co-exist in the same patient. Although all the possible combinations of the above-mentioned manifestations may occur, clusters of commonly co-existing involvements (also referred to as 'disease phenotypes') have been suggested, namely 'mucocutaneous and articular', 'peripheral vascular and extra-parenchymal neurological' and 'parenchymal neurological and ocular' phenotypes have been described. Patient-specific demographic and genetic features have been described as positively or negatively associated with specific disease phenotypes. This review will focus on the different clinical features of Behçet's syndrome, summarizing current evidence on the distinct disease manifestations as well as the major phenotypes

    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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