1,721,072 research outputs found
HMG CoA reductase inhibitors (statins) for people with chronic kidney disease not requiring dialysis
No full textBenefits and Harms of Statin Therapy for Persons With Chronic Kidney Disease A Systematic Review and Meta-analysis
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HMG CoA reductase inhibitors (statins) for dialysis patients
Full text linkBackground: Cardiovascular disease accounts for more than half the number of deaths among dialysis patients. The role of HMG CoA reductase inhibitors (statins) in the treatment of dyslipidaemia in dialysis patients is unclear and their safety has not been established. Objectives: To assess the benefits and harms of statins in peritoneal dialysis (PD) and haemodialysis patients (HD). Search strategy: We searched MEDLINE, EMBASE, the Cochrane Central Register of Controlled trials (CENTRAL, in The Cochrane Library), the Cochrane Renal Group's specialised register and handsearched reference lists of textbooks, articles and scientific proceedings. Selection criteria: Randomised controlled trials (RCTs) and quasi-RCTs comparing statins with placebo, no treatment or other hypolipidaemic agents in dialysis patients. Data collection and analysis: Two authors independently assessed study quality and extracted data. Statistical analyses were performed using the random effects model after testing for heterogeneity. The results were expressed as mean difference (MD) for continuous outcomes and risk ratios (RR) for dichotomous outcomes with 95% confidence intervals (CI). Main results: Fourteen studies (2086 patients) compared statins versus placebo or other lipid lowering agents. Compared to placebo, statins did not decrease all-cause mortality (10 studies, 1884 patients; RR 0.95, 95% CI 0.86 to 1.06) or cardiovascular mortality (9 studies, 1839 patients: RR 0.96, 95% CI 0.65 to 1.40). There was a lower incidence of nonfatal cardiovascular events with statins compared to placebo in haemodialysis patients (1 study, 1255 patients; RR 0.86, 95% CI 0.74 to 0.99). Compared with placebo, statin use was associated with a significantly lower end of treatment average total cholesterol (14 studies, 1823 patients; MD -42.61 mg/dL, 95% CI -53.38 to -31.84), LDL cholesterol (13 studies, 1801 patients; MD -43.06 mg/dL, 95% CI -53.78 to -32.35) and triglycerides (14 studies, 1823 patients: MD -24.01 mg/dL, 95% CI -47.29 to -0.72). There was similar occurrence of rhabdomyolysis and elevated liver function tests with statins in comparison to placebo. Authors' conclusions: Statins decreased cholesterol levels in dialysis patients similar to that of the general population. With the exception of one study, studies were of short duration and therefore the efficacy of statins in decreasing the mortality rate is still unclear. Statins appear to be safe in this high-risk population. Ongoing studies should provide more insight about the efficacy of statins in reducing mortality rates in dialysis patients. © 2009 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd
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
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