1,720,977 research outputs found
Amniotic membrane reduces bile duct ligation-induced liver fibrosis
No full textRecently, stem/progenitor cell transplantation has been proposed as potential treatment for chronic liver disorders as an alternative to organ/hepatocyte transplantation. In this study, based on the fact that amniotic membrane (AM) has long been applied in clinic due to its anti-inflammatory and anti-scarring properties and that AM-derived cells display multipotent differentiation potential and immunomodulatory features, we investigated the potential application of human AM as an innovative therapeutic approach.
We evaluated the effects of hAM on biliary-type liver fibrosis induced in rats through bile duct ligation (BDL). A fragment of hAM was applied onto the liver surface after BDL and the rats were euthanised after 2, 4 and 6 weeks. The severity of liver fibrosis was assessed both semi-quantitatively by the Knodell scoring system and quantitatively, by digital image analysis, evaluating liver areas occupied by the ductular reaction (CK 19-positive cells), activated myofibroblasts (alpha-SMA-positive cells) and collagen deposition (Masson's staining).
hAM-treated rats displayed significantly lower liver fibrosis with respect to control rats. Indeed, in contrast with BDL rats which showed a progression of fibrosis to cirrhosis from week 4 to week 6, fibrosis in BDL+hAM rats was confined at the portal/periportal area, with collagen deposition at about 50% of levels observed in control rats. Concomitantly, AM application slowed progression of the ductular reaction and significantly reduced the area occupied by myofibroblasts.
These findings suggest that human AM patching might counteract fibrosis progression in BDL-injured livers and could represent a new strategy to limit hepatic damage associated with fibrotic degeneratio
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Application of human amniotic membrane on rat liver following left hepatectomy : evaluation of liver reaction
No full textOver past decades, the numerous unique characteristics of human amniotic membrane (hAM), such as its anti-inflammatory and antifibrotic properties, justified the frequent use of this material in human reparative surgery and experimental animal disease models. In order to investigate the potential of amniotic membrane to promote hepatic regeneration, we applied the membrane to the external surface of hepatectomized rat livers and assessed hepatocyte proliferation rate and tissue reaction at 1, 3, 7 and 14 days after surgery. Clinical and histopathological data were collected and compared with hepatectomized control rats which received no hAM transplantation and were sacrificed at the same intervals.
In both control and hAM-transplanted animals, a rapid rise in mitotic activity was first observed near the resection, followed by a higher peak in mitoses at day 3 in distant areas. The number of binucleated cells, which decreased after partial hepatectomy, increased during liver regeneration, and this was observed more so in hAM transplanted animals. In this group, at day 7, hAM was adherent to the liver capsule in association with interposed palisades of tightly packed fibroblast-like cells. Discrete areas of partial resorption of hAM were observed at day 14. The parenchyma did not show any morphologically appreciable signs of degeneration or inflammatory infiltration in hAM-transplanted animals.
Our data suggest that application of hAM membrane to the surface of resected rat livers does not impede normal recovery and actually induces a slight improvement in hepatocyte proliferation without any evident signs of rejection against xenogeneic human transplanted membran
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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