1,721,213 research outputs found

    Pathophysiological role of the renin-angiotensin system on erectile dysfunction.

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    BACKGROUND: The renin-angiotensin system (RAS) has been shown to play an active role within the erectile tissues. The aim of this narrative review is to summarize the literature addressing the pathophysiological role of RAS on erectile function. Additionally, we update evidence on recent findings on the role of the Ang-(1-7) and Mas receptor on the erectile function and its therapeutic potential for treating erectile dysfunction (ED). MATERIALS AND METHODS: This narrative review is based on the material searched and obtained via MEDLINE and PubMed up to November 2012. The search terms we used are 'angiotensin, erectile dysfunction, renin, Mas receptor' in combination with 'pathophysiology, fibrosis, pathways'. RESULTS: The levels of angiotensin (Ang) II, the main component of this system, are increased in the corpus cavernosum as compared to those found in the systemic circulation. Moreover, emerging evidence indicates that an increased activity of Ang II via AT1 receptor might contribute to the development of ED, whereas the pharmacological blockage of Ang II/AT1 actions has beneficial effects on the erection. On the other hand, the heptapeptide Ang-(1-7), known as a major endogenous counter-regulator of Ang II actions, favours penile erection via the activation of Mas receptor. CONCLUSIONS: Ang-(1-7) and Mas receptor pathway might be considered as a promising therapeutic target for the treatment of ED

    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
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