1,720,985 research outputs found
A prospective study of plasma nitrates following human heart transplantation: relevance to myocardial function
No full textBackgroundNitric oxide (NO) has been shown to affect myocardial function in positive and negative inotropic ways. Expression of inducible nitric oxide synthase and release of nitric oxide into the circulation has been associated with acute rejection in animal studies. The role of NO and the associated myocardial dysfunction seen during acute rejection in humans has not been adequately defined. In a prospective sequential study, we have studied the relationship between plasma nitrate and biopsy-proven acute rejection, and systolic and diastolic function after heart transplantation.MethodsBiopsies were performed weekly and then fortnightly up to 12 weeks after transplantation and on clinical indication of rejection in 37 patients. Plasma nitrates were obtained on the morning of each biopsy (total 341). An echocardiogram was performed immediately prior to each biopsy in which the systolic parameters, ejection fraction (EF) and fractional shortening (fs), and the diastolic parameters, isovolumetric relaxation time (IVRT), mitral valve pressure half-time (MVPHT), mitral valve deceleration time (MVDT), e:a ratio, and a wave duration, were measured.ResultsPlasma-nitrate level showed no significant correlation with the systolic parameters, EF or fs, or with changes in EF or fs. No significant correlation was found between plasma-nitrate level and the diastolic parameters IVRT, MVPHT, MVDT, mitral valve a wave duration, or e:a ratio.ConclusionsThis study has shown no correlation between plasma nitrate and impaired systolic or diastolic function after heart transplantation. Instead there was a weak trend for elevated nitrate to be associated with better systolic function
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Tumor necrosis factor-? is expressed in donor heart and predicts right ventricular failure after human heart transplantation
No full textBackground—Myocardial failure is an important problem after heart transplantation. Right ventricular (RV) failure is most common, although its mechanisms remain poorly understood. Inflammatory cytokines play an important role in heart failure. We studied the expression of tumor necrosis factor (TNF)-? and other cytokines in donor myocardium and their relationship to the subsequent development of RV failure early after transplantation. Methods and Results—Clinical details were obtained, and ventricular function was assessed by transesophageal echocardiography in 26 donors before heart retrieval. A donor RV biopsy was obtained immediately before transplantation, and each recipient was followed for the development of RV failure. Reverse transcriptase–polymerase chain reaction was performed to detect TNF-?, interleukin-2, interferon-, and inducible nitric oxide synthase expression. Eight of 26 recipients (30.8%) developed RV failure. Seven of these 8 (87.5%) expressed TNF-?, but only 4 of the 18 (22.2%) who did not develop RV failure expressed TNF- (P<0.005). As a predictor of RV failure, TNF-? mRNA had a sensitivity of 87.5%, a specificity of 83.3%, a positive predictive value of 70%, and a negative predictive value of 93.7%. Western blotting demonstrated more TNF-? protein in the myocardium of donor hearts that developed RV failure (658±60 versus 470±57 optical density units, P<0.05). Immunocytochemistry localized TNF-? expression to cardiac myocytes. Reverse transcriptase–polymerase chain reaction detected interferon- in 2 (7.7%), interleukin-2 in 1 (3.8%), and inducible nitric oxide synthase mRNA in 1 (3.8%) of the 26 donor hearts, none of which developed RV failure. Conclusions—TNF-? expression in donor heart cardiac myocytes seems to predict the development of RV failure in patients early after heart transplantation
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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