1,721,005 research outputs found
Hypotony after 25-gauge vitrectomy
No full textPurpose To describe the incidence of hypotony after 25-gauge vitrectomy and to identify preoperative and intraoperative factors that influence the occurrence of hypotony. Design Retrospective, nonrandomized, interventional case series. Methods We reviewed 122 consecutive cases of 25-gauge vitrectomy for all surgical indications. The primary outcome measure was intraocular pressure (IOP) at postoperative day 1, measured with Goldmann tonometry. Secondary outcome measures were clinical signs of hypotony and other complications. Results Hypotony, defined as an IOP of 5 mm Hg or less, was found in 13.1% of cases on postoperative day 1. Clinical signs of hypotony were encountered in 7 eyes (5.7%). The risk of hypotony was significantly lower in cases with air or gas tamponade (3.3%) than in cases without tamponade (22.4%). Hypotony was encountered more often in reoperations (29.9%) than in primary operations (9.2%; statistically significant difference). In cases in which intravitreal triamcinolone was used, the risk of hypotony was significantly higher (35.3%) than in cases without triamcinolone (10.3%). Phakic eyes had significantly less chance of hypotony (6.7%) than pseudophakic eyes (15.6%) and eyes undergoing combined phacoemulsification and vitrectomy (25.0%). At postoperative day 7, all cases of hypotony recovered spontaneously. None of our cases developed endophthalmitis. Conclusion Our results show that a transient hypotony occurs commonly after 25-gauge vitrectomy. Hypotony was significantly influenced by tamponade, reoperation, intraoperative lens status, and use of intravitreal triamcinolone. Although all cases of hypotony recovered spontaneously without permanent damage, the high frequency of hypotony does impose potential risks. Increased vigilance with focus on perioperative antisepsis and low tolerance of sclerotomy leakage are important for the prevention of endophthalmitis. Strategies aimed at lowering the risk of hypotony are needed to improve the safety of this promising technique
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Surgery for floaters
No full textOur results show that straylight values decreased signif- icantly following vitrectomy. The straylight value of most eyes returned into the normal range. The impressive de- crease in straylight may explain the previously described uniformly high satisfaction of patients undergoing this pro- cedure.1 If validated in prospective studies, quantifying straylight may be valuable to help understand the subjective complaints of glare disability in patients with floaters. We believe that in carefully selected individuals, vitrectomy may be effective in decreasing glare. Straylight measure- ment can guide clinician and patient in the often difficult decision on surgical treatment of floaters
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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
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