1,721,020 research outputs found

    Small-for-flow liver failure after extended hepatectomy: hot questions and an update

    No full text
    Small-for-size liver syndrome and posthepatectomy liver failure remain a major challenge for surgeons. Recently, updates in literature points to describe this two syndrome as two face of the same coin. These syndromes are characterized by hyperbilirubinemia, coagulopathy, hyper-GGT, high portal pressure and flow in liver remnant, occurring within the first postoperative week. It can lead to post-operative sepsis and bleeding, increasing mortality and morbidity. Despite the large experience in the field of transplantation, few studies are focused on small-for-size syndrome after major hepatectomy. For years, scientists were focused on the size of liver remnant, supposing a small liver remnant, in relation with the primary liver size, was the cause of the syndrome. The strategies used to prevent it after transplantation, have however shown a predominant role of high portal pressure and flow, leading to an alteration in functional regeneration of liver parenchyma, as the prevalent mechanism. According to these evidences, we suggest adopting another nomenclature for the two syndromes: small-for-flow-liver failure. In this article, we analyze and summarize different experiences, proposing our inward algorithm, including the role of portal flow and pressure measurements. This review seeks to be an operative instrument for surgeons and hepatologists in an effort to find a common point of view regarding small for flow liver failure and its management strategies

    Going Beyond Counting First Authors in Author Co-citation Analysis

    Full text link
    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

    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 link
    We 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

    Hepatic uptake index in the hepatobiliary phase of gadolinium ethoxybenzyl diethylenetriamine penta acetic acid-enhanced magnetic resonance imaging estimates functional liver reserve and predicts post-hepatectomy liver failure

    No full text
    Background: Recent evidence suggests that gadolinium ethoxybenzyl diethylenetriamine penta acetic acid-enhanced (Gd-EOB-DTPA) magnetic resonance imaging may be used to evaluate liver function. The aim of this study was to assess whether the signal intensity of Gd-EOB-DTPA magnetic resonance imaging may be used to predict functional liver reserve and posthepatectomy liver failure in patients undergoing hepatectomy for liver tumors.Methods: This is an observational retrospective study on 137 preoperative Gd-EOB-DTPA magnetic resonance imaging of patients undergoing hepatectomy between 2015 and 2018. Mean signal intensity of liver (L-20) and spleen (S-20) were measured on T1-weighted single-breath-hold 3-dimensional fatsaturated gradient echo sequences acquired 20 minutes after Gd-EOB-DTPA administration. The hepatocellular uptake index of liver volume (V-L) was calculated with the formula V-L(L-20/S-20] - 1) and was tested with several score systems for liver diseases and to the occurrence of post-hepatectomy liver failure.Results: Patients with diseased liver had significantly lower values of hepatic uptake index in comparison with those with normal function. This was found for a Model for End-Stage Liver Disease score <= 9 versus >9 (P = .04), combination of bilirubin and cholinesterases levels score <= 2 versus >2 (P = .02), albumin to bilirubin grades (P = .03), and Humanitas score <= 6 versus >6 (P = .03). Twenty-two patients (16%) developed posthepatectomy liver failure, and 2 (1.4%) died within 90 days. The hepatocellular uptake index was significantly lower in those patients with post-hepatectomy liver failure (P < .01). Receiver operating characteristics curve analysis revealed valuable hepatocellular uptake index ability in predicting post-hepatectomy liver failure (area under the curve = 0.84; 95% confidence interval, 0.71-0.92; P < .01), with a cutoff value of 574.33 (98% sensitivity; 83% specificity).Conclusion: The hepatocellular uptake index hepatocellular uptake index measured on preoperative Gd-EOB-DTPA magnetic resonance imaging identifies patients with diseased liver and predicts post-hepatectomy liver failure. This index could be used to discern those patients at higher risk of complications after hepatectomy. (C) 2020 Elsevier Inc. All rights reserved

    Dispelling the Myths Behind First-author Citation Counts

    Full text link
    We 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

    Author Index

    No full text
    Nao informado
    corecore