1,720,970 research outputs found
Cystic Neoplasm of the Pancreas
No full textCystic neoplasms of the pancreas (CNPs) are not considered as rare entities any more. Imaging-based population studies attested an overall prevalence of 2 %, but that becomes five times higher on individuals of more than 70 year old. This family of neoplasms includes a wide spectrum of benign, borderline, and malignant lesions whose actual biological behavior has not been completely clarified yet. Moreover, the management of CNPs still represents a challenge for gastrointestinal (GI) specialists. While many CNPs have an indolent behavior that justifies surveillance, others should be resected because of the risk of progression to invasive cancer. Due to the high morbidity related to pancreatic resections, the surgeon should balance very carefully the advantages of a radical resection with the risks of an unrequested dangerous procedure. We reviewed the current issues regarding CNPs, with a particular focus on the clinical and radiological features that are integrated in the current guidelines and that drive the management of these patients
Pancreaticoduodenectomy for distal cholangiocarcinoma: surgical results, prognostic factors, and long-term follow-up
No full textPurpose Prognostic indicators for distal cholangiocarcinoma have not been widely confirmed because of its rarity. Despite the early appearance of symptoms, it has a very poor prognosis. The aim of this study was to identify prognostic factors in patients undergoing pancreaticoduodenectomy (PD) for distal bile duct cancer (DBDC) in a high-volume center for pancreatic disease. Methods From January 2000 to December 2013, 1490 PD were performed for periampullary disease. Data from all patients with histologically proven cholangiocarcinoma were reviewed. Preoperative data, post-operative complications, pathologic features, and survival were investigated. Results Among 50 histologically proven DBDC (3.3 %), 4 patients who underwent CBD resection were excluded. Thus, the study population consisted of 46 patients. Overall surgical morbidity rate was 67.4 %; mortality was nil. Major complications were pancreatic fistula (47.8 %), abdominal collections (34.8 %), post-pancreatectomy hemorrhage (21.7 %), and delayed gastric emptying (10.9 %). The majority of resections were R0 (73.9 %). The presence of metastatic lymph nodes (N1) was identified in 76.1 % of cases. Among N1 cases, the most frequently involved lymph nodes were pancreaticoduodenal nodes (50 %), hepatoduodenal ligament nodes (21.7 %), superior mesenteric artery nodes (8.7 %), and anterior hepatic artery nodes (4.3 %). Overall, survival rates were 88.8, 40, and 18 % at 1, 3, and 5 years, respectively. Median survival was 31 months. By univariate analysis, only tumor grading and nodal metastasis were predictors of poor prognosis (p<0.05). These findings were not confirmed in multivariate analysis. Conclusions This study shows that DBDC is a rare entity even if large surgical series are reviewed. Tumor differentiation and nodal status have been confirmed as important prognostic factors. Pancreaticoduodenectomy remains the procedure of choice in order to obtain free surgical margins and in order to harvest the correct number of lymph nodes for a correct staging
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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