1,721,044 research outputs found
New organ allocation criteria in liver transplantation
No full textSummary. The organ allocation modality in the liver transplant represents a fundamental step for the correct success of the transplantation procedure. The practical effects deriving from the adoption of the organ allocation models do not imply only clinical repercussions but also concern important ethical aspects. Alongside the general principles of fairness, justice and transparency, the organ allocation models should be aimed at providing for each patient who waits for an organ, the possibility of accessing it, preserving and maximizing the outcome of the transplant in terms of survival and quality of life. Balancing successfully the clinical and ethical aspects in an allocation model is particularly difficult and probably not completely feasible. In this brief review, the general principles governing the different models of organ allocation in liver transplantation are addressed. A particular description of the decision-making process that led to the sharing in Italy of a new allocation model based on the concept of the transplant benefit is illustrated. In this model we have tried to combine the two fundamental principles that for many years have guided the choice of allocation models, respectively based on the criteria of urgency and utility
Updates on antiviral therapy for chronic hepatitis C.
No full textHepatitis C virus (HCV) infection is a major public health problem around the world and it is estimated that there are about 200 million infections globally. The majority of HCV infected patients develop chronic infection, which can progress to liver cirrhosis, hepatocellular carcinoma, and liver failure. Since the discovery of the virus in 1989, impressive progress has been made in the treatment of HCV hepatitis. However, the actual standard of care in treating HCV infection, represented by the combination therapy of pegylated interferon alpha 2a or 2b with ribavirin, fails to cure near half of treated patients. This paper aimed to trace a brief overview of the progress made by interferon-based treatments for HCV hepatitis since their introduction in the early 1990s, and to highlight the results of recent clinical studies concerning new and emerging drugs
Challenges and future developments in liver transplantation
No full textLiver transplantation (LTLT) has become the treatment of choice for a wide range of liver diseases in both adult and pediatric patients. Until recently, the largest proportion of LTLT in adults, were performed in patients with hepatitis C (HCV) related cirrhosis. The recent availability of safe and effective direct antiviral agents to cure HCV infection in almost all patients whatever the HCV genotype and severity of liver disease, will reduce the need for LTLT in this category of recipients. Thus, it is presumed that in the next 1 to 2 decades HCV related liver disease will diminish substantially, whereas non-alcoholic steato-hepatitis (NAS H) will correspondingly escalate as an indication for LTLT. The greatest challenges facing LTLT remain the limited supply of donor organs, and the need for chronic immunosuppression, which represent the true obstacles to the greater application and durable success of the LTLT procedure. This review aimed to highlight, in different sections, the main open issues and future developments in LTLT. These will be focused to explore current and future strategies to maximize the use of limited organs, to offer an update on potential new approaches to immunosuppression and to imagine new indications for LTLT when the number of patients awaiting transplants for HCV related liver disease is reduced
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
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