1,720,991 research outputs found
Patologia dell'aorta toracica : Generalità e problematiche dell'angiografia intraoperatoria
Aortic Graft Infections: Treatment With Arterial Allograft
Since its reintroduction by Kieffer in 1991, many authors have used arterial allografts for surgical management of vascular prosthetic graft infection. During a decade, 25 patients with aortic graft infection were treated using in situ revascularization with arterial allograft. There were 23 male and 2 female patients of mean age of 65.7 +/- 8.8 years (range, 43-78). Antibiotic therapy was administered for a mean time of 26 +/- 5 days (range, 21-45) in the postoperative period. The mean follow-up time was 2.3 +/- 3 years (range, 22 days-8.7 years). The mean in-hospital postoperative stay was 29.6 +/- 14 days (range, 9-68). An aorto-enteric fistula (AEF) was present in 11 patients (44%), producing gastrointestinal bleeding. The overall mortality rate was 13 of 23 (56.5%) patients. The allograft-related mortality rate was 5 of 23 (22%). The overall allograft-complicated patient rate was 15 of 23 (65%); we observed 18 allograft ruptures in 12 patients and 8 allograft thromboses in 6 patients. The overall amputation rate was 8.7% (2 of 23). Age of the recipient older than 69 years (P = .02), positive preoperative marked-leukocyte scanning (P = .04), and persistent postoperative leukocytosis (P = .03) were significant variables associated with an increased risk of allograft-related complications. The use of arterial allografts for aortic graft infections represents an interesting alternative for the treatment of graft infection. Nevertheless, there are some problems related to the durability of this type of graft, which can still be considered as a "bridge transplant.
Going Beyond Counting First Authors in Author Co-citation Analysis
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
“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
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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