1,721,112 research outputs found

    Effect of the Etiology of Viral Cirrhosis on the Survival of Patients with Hepatocellularr Carcinoma

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    OBJECTIVES: The aim of this study was to assess whether hepatocellular carcinoma occurring in the setting of hepatitis B or C virus infection has different prognosis. METHODS: We performed a multicentric case-control study comparing 102 pairs of patients affected by hepatitis B virus- or hepatitis C virus-related hepatocellular carcinoma. Patients were matched for sex (male/female: 84/18 pairs), age, center, and period of enrollment, underlying chronic liver disease (cirrhosis/chronic hepatitis: 97/5 pairs), Child-Pugh class (A/B/C: 70/25/7 pairs), hepatocellular carcinoma stage (nonadvanced/advanced: 50/52 pairs) and, when possible, modality of cancer diagnosis (75 pairs: 47 during and 28 outside surveillance). RESULTS: In the whole population, patients with hepatitis B tended to have a poor prognosis than those with hepatitis C (p = 0.160), and this difference became statistically significant among the patients with an advanced hepatocellular carcinoma (p = 0.025). Etiology, Child-Pugh class, gross pathology, and alpha-fetoprotein were the significant independent prognostic factors in the whole population. The distribution of these prognostic factors did not differ between patients with hepatitis B or hepatitis C, both in the whole population and in the subgroup of advanced hepatocellular carcinomas. CONCLUSION: Hepatitis B virus-related hepatocellular carcinomas have a greater aggressiveness than hepatitis C virus-related tumors, which becomes clinically manifest once they have reached an advanced stage

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    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

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    “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

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    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

    Randomized Control Trials on Chemoembolization for Hepatocellular Carcinoma.

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    Hepatocellular carcinoma (HCC) generally occurs in patients with cirrhosis. Curative options, such as liver transplantation, hepatic resection, and percutaneous alcohol injection, are applicable to a minority of cases. Because systemic chemotherapy and radiation therapy provide dismal results, transarterial chemoembolization (TACE) remains the sole approach to antagonizing the cancer growth in most patients. Although most tumors show an extensive necrosis after TACE, the beneficial effect on survival has not been properly substantiated, so that its application still remains a matter of debate. This review analyzes the results of randomized clinical trials on TACE. In most studies, TACE did not increase the survival of patients as compared with the palliative treatment. However, several methodologic and technical pitfalls may have adversely affected the results of these trials, such as inadequate patient selection and statistical power of the study design, a nonoptimal procedure, and treatment repetition not tailored to the cancer response and patient tolerance. Nonetheless, the literature will hardly be enriched by new trials including untreated patients because, wrong or right, TACE is currently considered the standard treatment of unresectable HCC. It seems more realistic to expect randomized studies comparing different techniques and time schedules of treatment, as well as TACE alone versus combined procedures

    Dispelling the Myths Behind First-author Citation Counts

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    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

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