1,720,996 research outputs found
Timing and protocols of clinical and endoscopic surveillance of Barrett's esophagus
No full textBarrett’s esophagus (BE) is a premalignant lesion in which normal squamous epi- thelium of the esophagus is replaced by metaplastic columnar epithelium of any histological subtype [1]. Several guidelines for diagnosing and managing BE have been published; however, they differ significantly among and within countries [1–3]. Only few large well-designed trials have been conducted so far [4–6]
Diagnostic yield of upper endoscopy according to appropriateness: A systematic review
No full textBackground/aim: Despite some official guidelines are available, a substantial rate of inappropriateness for upper gastrointestinal (UGI) endoscopies has been reported. This study aimed to estimate the inappropriate rate of UGI in different countries, also including the diagnostic yield. Methods: A systematic review of studies on UGI endoscopy appropriateness was performed by adopting official guidelines as reference standard. Diagnostic yield of relevant endoscopic findings and cancers was compared between appropriate and inappropriate procedures. The Odd Ratio (OR) values and the Number-Needed-to-Scope (NNS) were calculated. Results: Data of 23 studies with a total of 53,392 patients were included. UGI indications were overall inappropriate in 21.7% (95% CI = 21.4–22.1) of the patients. The inappropriateness rate significantly (P < 0.0001) decreased from 35.1% in the earlier studies to 22.1%–23% in the more recent ones. A relevant finding was found in 43.3% of appropriate and in 35.1% of inappropriate endoscopies (P < 0.0001; OR: 1.42, 95% CI = 1.36–1.49; NNS = 12). Prevalence of cancers was also higher in appropriate than in inappropriate UGIs (2.98% vs. 0.09%, P < 0.0001; OR = 3.33; NNS = 48). The prevalence of detected cancers significantly (P < 0.004) increased from 1.38% in the earlier studies to 2.11% in the more recent ones, whilst prevalence of other relevant findings remained similar. Conclusions: Rate of inappropriate UGI endoscopies is still high. Diagnostic yield of appropriate endoscopies is higher than that of inappropriate procedures, including upper GI cancers. Therefore, implementation of guidelines in clinical practice is urged
Augmented endoscopy in Barrett's esophagus:zoom endoscopy, traditional and virtual chromoendoscopy
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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
Comparing intravenous and oral proton pump inhibitor therapy for bleeding peptic ulcers following endoscopic management: a systematic review and meta-analysis
No full textAppropriate 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
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