1,720,970 research outputs found
Primary carcinoid tumor of the cystic and common bile ducts.
No full textWe report a case of primary carcinoid tumor arising at the confluence of the cystic and common bile ducts. The patient was a 64-year-old woman who developed a sudden onset of biliary colic and jaundice. Computerized tomography and nuclear magnetic resonance showed a mass lesion close to the head of the pancreas. At laparotomy a nodular lesion was found at the confluence of the cystic and common bile ducts. Microscopic observation revealed a type B-C carcinoid (Soga's classification) with positive immunoreactivity to chromogranin and cytokeratin. The presence of neurosecretory intracytoplasmic granules was demonstrated by electron microscopy. Flow cytometry showed diploid DNA content of the neoplastic cells with less than 5% of the nuclei in the S-phase region
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
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
Gastric Epithelial Dyspalsia. How clinico-pathgologic background relates to management.
No full textBACKGROUND:
Gastric epithelial dysplasia (GED) in metaplastic mucosa is considered the most advanced preinvasive lesion in the multistep morphogenesis of intestinal-type gastric cancer (GC). The rate of GED's evolution into GC is still under debate and probably is related to pathologic and clinical parameters other than the dysplasia itself. The aim of this study was to evaluate whether clinical aspects (sex and age) and/or morphologic variables (GED grade, coexisting atrophic gastritis) are relevant to the outcome of dysplasia, with a view toward initiating the establishment of a rational follow-up protocol for practical GED management.
METHODS:
Ninety-three patients harboring GED (G1: 56, G2:34, G3:18) were followed for more than 12 months according to a previously-agreed protocol. Regression, progression, or evolution into GC were detected for each grade of GED. Multivariate analysis was used to check the independence of clinical and pathologic variables in the progression of GED into more severe dysplastic lesions and/or as risk factors for evolution into GC.
RESULTS:
Age, male sex, GED grade and grade of coexisting atrophic gastritis proved independent risk factors for GED progression, with no significant interactions. Only GED grade (G2 and G3) was significantly associated with carcinomatous evolution. In G1-GED, age and the grade of coexisting atrophy proved to be independent risk factors for carcinomatous evolution.
CONCLUSIONS:
In G1-GED, more stringent follow-up should be recommended for older patients with coexisting high grade atrophic gastritis; stringent follow-up is always mandatory for G2-GED; and a surgical approach is justified in G3-GED
Gastric epithelial dysplasia in the natural history of gastric cancer: a multicenter prospective follow-up study. Interdisciplinary Group on Gastric Epithelial Dysplasia.
No full textBackground/Aims: Because the precancerous significance of gastric epithelial dysplasia (GED) is still under debate, this study attempts to ascertain whether a prospective follow-up of GED can contribute to clarifying its clinical and pathological relationships with gastric cancer (GC). Methods: One hundred twelve patients with mild (Gi), moderate (G2), and severe (G3) GED or diagnosed as indefinite for dysplasia were prospectively followed up with a standardized endoscopic and bioptic protocol. Results: Evaluation of GED outcome refers only to 93 patients with a follow-up period longer than 12 months. Regression of dysplasia was documented in 36%, 27%, and 0% of G1, G2, and G3 GED cases, respectively. Progression to more severe dysplasia or evolution into GC was detected in 21%, 33%, and 57% of G1, G2, and G3 GED cases, respectively. Evolution into GC was documented for all grades of dysplasia and correlated significantly with high-grade atrophic gastritis. A high prevalence of early GC (86.9%) was also observed. Conclusions: GED is a preinvasive lesion, and carcinomatous evolution increases proportionally with its histological grade. Bioptical follow-up is mandatory for all histological grades of GED and significantly increases the likelihood of GC being detected in its early stages
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