1,720,964 research outputs found
Differential regulation of V-ATPase and NHE3 in rat cholangiocytes after bile duct ligation
No full textManagement of Coeliac and Hepatic Artery Aneurysms: An Experience of 84 Cases
Full text linkObjective: To report outcomes following open or endovascular treatment of true hepatic and coeliac artery aneurysms at a single referral centre. Methods: This was a retrospective cohort study of consecutive patients treated for true hepatic and coeliac artery aneurysms between May 2002 and December 2021. Outcome measures included complications, graft patency, and survival rate. Results: Overall, 84 patients were included with a median age of 63 years (interquartile range 55, 79). The majority (76%) of the patients were men. Frequent comorbidities included a history of tobacco (69%), hypertension (65%), hyperlipidaemia (32%), and diabetes (15%). Multiple synchronous aneurysms were detected in 22 patients (26%). There were 33 (39%) symptomatic aneurysms (abdominal pain without rupture [n = 18], rupture [n = 10], and sepsis [n = 5]). Seventeen patients (20%) had mycotic aetiology. Fifty patients (60%) underwent endovascular treatment with either covered stent placement (n = 29) or coil embolisation (n = 21), and 34 patients (40%) were treated with open surgery using allogenic iliac artery (n = 15), autologous saphenous vein (n = 15), GoreTex graft (n = 2), or ligation (n = 2). The complication rate was 32% in the open group and 18% in the endovascular group (p = .048). The overall 90 day post-operative mortality rate was 1.2%, five year primary patency was 90.0%, five year survival rate was 81.2%, and mean follow up was 6.9 ± 4.2 years. Conclusion: Endovascular treatment is the preferred approach whenever technically possible. Despite higher post-operative morbidity, an open approach with vascular reconstruction using autologous or allogenic vascular grafts yields acceptable long term results
Differential regulation of vacuolar H+-ATPase and Na+/H+ exchanger 3 in rat cholangiocytes after bile duct ligation
No full textThe cholangiocytes lining the intrahepatic bile ducts modify the primary secretion from the hepatocytes. The cholangiocytes secrete HCO3- into bile when stimulated with secretin in many species, including man. However, in rats, secretin stimulation neither affects biliary HCO3- concentration nor bile flow, whereas following bile duct ligation (BDL) it induces hypercholeresis with significant increase of NaHCO3 concentration. We hypothesized that BDL might affect the expression of cholangiocyte H+ transporters and thereby choleresis, and determined the expression and localization of the 31 kDa vacuolar type H+-ATPase (V-ATPase) subunit and of Na+/H+ exchanger NHE3 in the livers of control and BDL rats by real- time PCR, in situ hybridization, immunoblotting, and immunohistochemistry. In controls, secretin had no effect on bile flow, whereas following BDL, secretin increased bile flow similar to threefold. V-ATPase and NHE3 were expressed in control cholangiocytes showing intracellular and apical distribution, respectively. BDL significantly up-regulated V-ATPase mRNA and protein expression and was associated with redistribution to the apical pole in similar to 60% of the cholangiocytes lining the small bile ductules. In contrast, NHE3 expression was significantly down-regulated by BDL at the mRNA and protein level. The data demonstrate expression of V-ATPase in rat cholangiocytes. BDL-induced down-regulation of NHE3 may contribute to a reduction of Na+ and HCO3- reabsorption and thus to their net secretion into bile. Apical localization of V-ATPase in cholangiocytes may indicate its involvement in pH regulation and/or HCO3- salvage to compensate for NHE3 down-regulation in BDL
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
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