1,721,095 research outputs found
In the Presence of Conceptual Heterogeneity, Results of Network Meta-analysis Comparing Therapies in Crohn's Disease Need to Be Interpreted With Caution
No full textTransbronchial needle aspiration: a systematic review on predictors of a successful aspirate.
No full textIs thrombolysis for intermediate-risk pulmonary embolism beneficial? The case of Emeritus Professor Crow
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Most appropriate animal models to study the efficacy of statins: A systematic review
No full textBackground: In animal models and clinical trials, statins are reported as effective in reducing cholesterol levels and lowering the risk of cardiovascular diseases. We have aggregated the findings in animal models - mice, rats and rabbits - using the technique of systematic review and meta-analysis to highlight differences in the efficacy of statins. Materials and methods: We searched Medline and Embase. After examining all eligible articles, we extracted results about total cholesterol and other blood parameters, blood pressure, myocardial infarction and survival. Weighted and standard mean difference random effects meta-analysis was used to measure overall efficacy in prespecified species, strains and subgroups. Results: We included in systematic review 161 animal studies and we analysed 120 studies, accounting for 2432 animals. Statins lowered the total cholesterol across all species, although with large differences in the effect size: -30% in rabbits, -20% in mice and -10% in rats. The reduction was larger in animals fed on a high-cholesterol diet. Statins reduced infarct volume but did not consistently reduce the blood pressure or effect the overall survival. Few studies considered strains at high risk of cardiovascular diseases or hard outcomes. Conclusions: Although statins showed substantial efficacy in animal models, few preclinical data considered conditions mimicking human pathologies for which the drugs are clinically indicated and utilized. The empirical finding that statins are more effective in lowering cholesterol derived from an external source (i.e. diet) conflicts with statin's supposed primary mechanism of action. © 2014 Stichting European Society for Clinical Investigation Journal Foundation
Systematic review with network meta-analysis: Comparative efficacy and safety of budesonide and mesalazine (mesalamine) for Crohn's disease
No full textBackground Budesonide and mesalazine (mesalamine) are commonly used in the medical management of patients with mild to moderate Crohn's disease. Aim To assess their comparative efficacy and harm using the methodology of network meta-analysis. Methods A comprehensive search of Medline, Embase, the Cochrane Library and ClinicalTrials.gov, through October 2014, was performed to identify randomised controlled trials (RCTs) that recruited adult patients with active or quiescent Crohn's disease, and compared budesonide or mesalazine with placebo, or against each other, or different dosing strategies of one drug. Results Twenty-five RCTs were combined using Bayesian network meta-analysis. Budesonide 9 mg/day, or at higher doses (15 or 18 mg/day), was shown superior to placebo for induction of remission [odds ratio (OR), 2.93; 95% credible interval (CrI), 1.52-5.39, and OR, 3.28; CrI, 1.46-7.55 respectively] and ranks at the top of the hierarchy of the competing treatments. For maintenance of remission, budesonide 6 mg/day demonstrated superiority over placebo (OR, 1.69; CrI, 1.05-2.75), being also at the best ranking position among all compared treatment strategies. No other comparisons (i.e. different doses of mesalazine vs. placebo or budesonide, for induction or maintenance of remission) reached significance. The occurrence of withdrawals due to adverse events was not shown different between budesonide, mesalazine and placebo, in both the induction and maintenance phases. Conclusions Budesonide, at the doses of 9 mg/day, or higher, for induction of remission in active mild or moderate Crohn's disease, and at 6 mg/day for maintenance of remission, appears to be the best treatment choice
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
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