1,720,982 research outputs found
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
PORTAL STUMP PRESSURE MONITORIZATION IN THE CONSCIOUS RAT AFTER PORTACAVL SHUNT ANF TOTAL LIVER ARTERIALIZATION WITH THE LEFT GASTRIC ARTERY
No full textHepatic regeneration induces normoglycemia in diabetic rats previously transplanted into the liver with a subtherapeutic islet mass
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Bone marrow derived liver stem cells (BDLSC) engraft more efficiently livers undergoing rejection than hepatocytes: a potential novel therapeutic approach for the treatment of liver rejection
No full textBACKGROUND: The definitive therapy for end-stage liver disease is orthotopic liver transplantation (OLT). However, rejection is still a major cause of mortality and morbidity following OLT. Hepatocyte transplantation has been used experimentally to treat liver diseases. The aim of this study was to investigate whether bone marrow-derived liver stem cells (BDLSC) and mature hepatocytes could repopulate transplanted livers undergoing rejection.
METHODS: OLT was carried out from D'Agouti (C3-positive female) into Lewis (C3-negative female) rats. BDLSC were transplanted from Lewis (male) into livers of D'Agouti (female) rats. Group A (n = 9) received intraportal normal saline. Groups B (n = 9) and C (n = 9) underwent intraportal transplantation of mature hepatocytes (Lewis female, 0.75 x 10(7)) and DBLSC (Lewis male, 5 x 10(4)) respectively. All groups received subtherapeutic immunosuppression (Cyclosporin 0.25 mg/kg/d) for 13 days. Liver repopulation was assessed using immunohistochemistry (C3 antigen-negative cells), in-situ hybridization, (Y-chromosome-positive BDLSC) and histologic assessment (hematoxylin and eosin) for rejection.
RESULTS: BDLSC and mature hepatocytes repopulated 62 +/- 12.3% and 2.5 +/- 1.7% of rejecting livers, respectively. BDLSC demonstrated formation of hepatic lobules and portal triads with little evidence of rejection 36 days after discontinuation of immunosuppression.
CONCLUSIONS: BDLSC can repopulate livers undergoing severe rejection. Moreover, BDLSC can differentiate into hepatocytes and cholangiocytes. This finding may have important clinical implications
Transplantation of bone marrow derived liver stem cells in a rodent model of liver transplantation
No full textIn vitro morphological and functional characterization of isolated porcine hepatocytes for extracorporeal liver support: bile acid uptake and conjugation.
No full textRecently, researchers have focused on the use of bioartificial liver (BAL) to support patients with fulminant hepatic failure (FHF). We have developed a cell-based BAL, consisting of porcine hepatocytes in a hollow- fiber bioreactor. To better characterize BAL metabolic functions in vitro, bioreactors were inoculated with 48-h-cultured, microcarrier-attached hepatocytes and perifused with recirculating human plasma that contained either 1 μCi of [24-14C] plasma-enriched cholate or 1 μCi of [24-14C] plasma-enriched taurocholate. Bile acids were sampled hourly and separated into four fractions (unconjugated, glycoconjugated, tauroconjugated, and sulfated) for radioactivity determination. Following 3 h perifusion, the glycoconjugated and sulfated bile acid fractions in the bioreactor extrafiber space were significantly elevated when compared to the recirculating plasma. During perifusion with taurocholate-enriched plasma, a relative decrease in the tauroconjugated fraction and an increase..
Serum bile acids in patients with acute liver failure supported with a bioartificial liver
No full textBACKGROUND: Serum bile acids are increased in liver failure, but the composition of the bile acid pool in this condition has not been studied in detail. This information is of interest because of dihydroxy bile acid toxicity.
METHODS: We measured serum bile acids by gas chromatography-mass spectrometry in 13 patients with fulminant liver failure and five patients with acute-on-chronic liver failure. Furthermore, serum bile acids were analysed in the same patients after 6 h of treatment with a bioartificial liver, consisting of a hollow-fibre cartridge with microcarrier-attached porcine hepatocytes and a charcoal column.
RESULTS: Pre-bioartificial liver serum bile acids demonstrated a high dihydroxy/trihydroxy ratio and were higher in patients with acute-on-chronic liver failure than in those with fulminant liver failure (452.8 +/- 98.6 vs. 182.1 +/- 39.7 micro mol/L; P < 0.05). Bioartificial liver treatment decreased significantly serum bile acids in patients with fulminant liver failure (-38.8%) and acute-on-chronic liver failure (-35.8%), with a decreased dihydroxy/trihydroxy ratio. In vitro, porcine hepatocytes in the bioreactor cleared most conjugated bile acid species from pooled patient plasma.
CONCLUSIONS: Acute liver failure is associated with very high serum levels of toxic bile acids that could contribute to the pathogenesis of the syndrome. Bioartificial liver treatment reduces both serum bile acid concentrations and the hydrophobicity of the bile acid pool
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