1,720,960 research outputs found
Current surgical management of peri-hilar and intra-hepatic cholangiocarcinoma
Full text linkCholangiocarcinoma accounts for approximately 10% of all hepatobiliary tumors and represents 3% of all new-diagnosed malignancies worldwide. Intrahepatic cholangiocarcinoma (i-CCA) accounts for 10% of all cases, perihilar (h-CCA) cholangiocarcinoma represents two-thirds of the cases, while distal cholangiocarcinoma accounts for the remaining quarter. Originally described by Klatskin in 1965, h-CCA represents one of the most challenging tumors for hepatobiliary surgeons, mainly because of the anatomical vascular relationships of the biliary confluence at the hepatic hilum. Surgery is the only curative option, with the goal of a radical, margin-negative (R0) tumor resection. Continuous efforts have been made by hepatobiliary surgeons in order to achieve R0 resections, leading to the progressive development of aggressive approaches that include extended hepatectomies, associating liver partition, and portal vein ligation for staged hepatectomy, preoperative portal vein embolization, and vascular resections. i-CCA is an aggressive biliary cancer that arises from the biliary epithelium proximal to the second-degree bile ducts. The incidence of i-CCA is dramatically increasing worldwide, and surgical resection is the only potentially curative therapy. An aggressive surgical approach, including extended liver resection and vascular reconstruction, and a greater application of systemic therapy and locoregional treatments could lead to an increase in the resection rate and the overall survival in selected i-CCA patients. Improvements achieved over the last two decades and the encouraging results recently reported have led to liver transplantation now being considered an appropriate indication for CCA patients
Discovery of a Rare Variant of the Arc of Bühler During Liver Procurement
No full textWe report a rare variant of the hepatic arterial supply observed during liver procurement from a 71-year-old female donor for whom an ischemic stroke caused brain death. Preoperative computed tomography showed a partially obliterated celiac trunk and an atypical arterial branch that coursed in a retropancreatic plane away from its origin at the superior mesenteric artery to anastomose with the common hepatic artery at the origin of the proper hepatic artery. The gastroduodenal artery and the dorsal pancreatic artery are the 2 conventional anastomotic arcades between the celiac trunk and the superior mesenteric artery. However, another potential anastomotic route is a rare physiological phenomenon known as the arc of Bühler, which, if present, connects the superior mesenteric artery with the celiac trunk or one of its branches. Although the arc of Bühler is known to occur in less than 3% of the general population, it could serve as a crucial anastomotic option in the case of median arcuate ligament syndrome or atheromatous obliteration of the celiac trunk. In our case, we were able to dissect and preserve the entire anastomotic arc from the donor. For arterial reconstruction during liver transplant, we anastomosed the arc of Bühler to the recipient’s hepatic artery at the origin of the gastroduodenal artery. The postoperative course was uneventful, and the recipient was in good health at the 6-month follow-up. The arc of Bühler, when present, is an important anastomotic option in hepatobiliary surgery to avoid potential damage to the arterial supply of the liver
Impact of the COVID-19 pandemic on liver donation and transplantation: A review of the literature
Full text linkThe coronavirus disease 2019 (COVID-19) pandemic has upended healthcare systems worldwide and led to an inevitable decrease in liver transplantation (LT) activity. During the first pandemic wave, administrators and clinicians were obliged to make the difficult decision of whether to suspend or continue a lifesaving procedure based on the scarce available evidence regarding the risk of transmission and mortality in immunosuppressed patients. Those centers where the activity continued or was heavily restricted were obliged to screen donors and recipients, design COVID-safe clinical pathways, and promote telehealth to prevent nosocomial transmission. Despite the ever-growing literature on COVID-19, the amount of high-quality literature on LT remains limited. This review will provide an updated view of the impact of the pandemic on LT programs worldwide. Donor and recipient screening, strategies for waitlist prioritization, and posttransplant risk of infection and mortality are discussed. Moreover, a particular focus is given to the possibility of donor-to-recipient transmission and immunosuppression management in COVID-positive recipients
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
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