1,721,086 research outputs found
Detection of hepatitis B virus pre-S1 and pre-S2 determinants in paraffin wax embedded liver tissue: importance of reagents used.
No full textEvidence for hepatitis B and other virus infection in HBsAg-negative chronic active hepatitis.
No full textAntibody to the hepatitis B core antigen (anti-HBc) was detected in sera from 6 (19%) of 32 patients with HBsAg-negative chronic active hepatitis. In three cases with the highest anti-HBc titers, core antigen was detected in liver cell nuclei and in one case HBsAg was also present in hepatocytes, suggesting continuing hepatitis B virus infection. During follow-up, anti-HBc titers fell slowly in those with no viral antigens in liver tissue, and in two cases with virus in the liver at presentation, viral antigens were no longer demonstrable four and eight years later. In one case, clearance of virus was preceded by the appearance of HBsAg in liver and serum, suggesting reactivation of viral replication. In three of the anti-HBc-negative cases a nuclear antigen unrelated to the hepatitis B virus was detected by immunofluorescence, and it is possible that liver disease in these patients may be related to persistent non-A, non-B virus infection
Reactivation of hepatitis B virus infection in two patients: immunofluorescence studies of liver tissue.
No full textTwo patients, 1 with chronic active hepatitis, the other with Goodpasture's syndrome, became HBsAg-positive after the start of immunosuppressive drug therapy. At the same time of presentation, sera contained anti-HBc antibodies of IgM and IgG class in the absence of HBsAg or anti-HBs and immunofluorescent studies of liver biopsy specimens showed core antigen in the nuclei of liver cells. It is suggested that these findings reflected an unusual pattern of hepatitis B virus infection with a very low level of viral replication and that the appearance of HBsAg in both serum and liver cells after immunosuppressive drug therapy was due to reactivation of this infection, possibly as a result of changes in levels of antibodies which suppress viral replication. In 1 patients, the change in viral replication was associated with continuing liver cell necrosis and progressive deterioration in liver functio
Specificity of T lymphocyte cytotoxicity to autologous hepatocytes in chronic hepatitis B virus infection: evidence that T cells are directed against HBV core antigen expressed on hepatocytes.
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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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