1,720,968 research outputs found
PROPOSED RAT MODEL FOR THE EVALUATION OF THE INFLUENCE OF HP VARIATIONS ON HELICOBACTER PYLORI VIRULENCE
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
Local staging of rectal cancer with transrectal ultrasound and endorectal magnetic resonance imaging: comparison with histologic findings
PURPOSE: The aim of the present study was to compare the accuracy of endorectal coil magnetic resonance imaging with transrectal ultrasound in staging rectal carcinoma. METHODS: Twenty-six consecutive patients with rectal carcinoma, histologically proven by endoscopic biopsy, were staged with both endorectal coil magnetic resonance imaging and transrectal ultrasound and then underwent radical surgery. The preoperative staging was compared with histologic findings of the operative specimen according to TNM classification. RESULTS: Endorectal coil magnetic resonance imaging showed better results but was not statistically significantly different from transrectal ultrasound in evaluating T (accuracy, 84.6 vs. 76.9 percent): four overstaged and no understaged cases for the former and five overstaged cases and one understaged case for the latter. Both procedures showed similar results in evaluating N: 81 percent sensitivity and 66 percent specificity for endorectal coil magnetic resonance imaging and 72 percent sensitivity and 80 percent specificity for transrectal ultrasound. CONCLUSIONS: An accurate locoregional staging of rectal cancer is essential for the planning of optimal therapy for rectal cancer. Endorectal coil magnetic resonance imaging and transrectal ultrasound showed similar results; the former is more expensive, whereas the latter is operator dependent. At present the use of endorectal coil magnetic resonance imaging seems to be justified only in selected low rectal cancers where transrectal ultrasound yielded doubtful results. However, a more extensive study is necessary to compare the advantages of these diagnostic techniques
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
PREVALENCE OF GASTROESOPHAGEAL REFLUX DISEAS IN HELICOBACTER PYLORI-POSITIVE PEPTIC ULCER DISEAS AND SHORT TERM EFFECTS OF ERADICATION TERAPHY
Magnetic resonance colonography versus conventional colonoscopy for the detection of colonic endoluminal lesions
Background and Aims: The most effective prophylaxis for colorectal cancer is endoscopic polypectomy. Prompted by the disadvantages of conventional colonoscopy (CC), we assessed the diagnostic ability of a promising alternative technique for detecting endoluminal masses: magnetic resonance colonography (MRC). Methods: Seventy consecutive patients referred for CC underwent preliminary MRC. The diagnostic ability of this technique in detecting colonic endoluminal lesions was determined, compared with that of CC, and related to the findings from histologic examination. Results: In detecting endoluminal lesions, MRC achieved a diagnostic accuracy similar to CC (sensitivity, 96%; specificity, 93%; positive predictive value, 98%; and negative predictive value, 87.5%). Conclusions: MRC could be useful in screening programs of patients at high risk for colon cancer. Patients with MRC-detected endoluminal lesions must undergo CC for histologic diagnosi
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