1,720,961 research outputs found
Bilateral internal mammary artery grafting in obese: outcomes, concerns and controversies.
No full textObese patients are generally considered unsuitable to receive bilateral internal mammary arteries (BIMA) during coronary artery bypass grafting (CABG) due to the perceived vulnerability to sternal wound infection and lack of evidence supporting long-term survival benefit. However, no consistent evidence currently discourages the use of BIMA in obese patients. The present review questions the common perception that obesity unacceptably increases the risk of sternal wound complications in patients receiving BIMA grafting. Moreover, the use of skeletonization harvesting technique is expected to further minimize such a risk. Our institutional experience confirmed that BIMA grafting is a safe strategy which does not increase operative mortality and does not significantly affect the incidence of sternal wound complications. On the other hand, a long term benefit in terms of overall survival and freedom from repeat revascularization from the use of BIMA was found
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
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
Association of the European Society of Cardiology echocardiographic probability grading for pulmonary hypertension with short and mid-term clinical outcomes after heart valve surgery
No full textBackground and aims: Pulmonary hypertension (PH) is associated with higher mortality and morbidity after valvular heart surgery, mainly through its adverse effect on right ventricular hemodynamic. Recently, the European Society of Cardiology (ESC) PH guidelines introduced a PH probability grading that lists additional parameters related to right ventricular dimensions. We evaluated the impact of such score on short- and mid-term outcomes in patients undergoing left heart valvular surgery. Methods and results: We included 60 consecutive patients (mean age 70 ± 9 years) undergoing left heart valvular surgery with or without coronary artery bypass. Patients were divided into 3 groups according to the PH probability: “low” (n = 18), “intermediate” (n = 18), or “high” (n = 24). The high PH probability group had higher rate of World Health Organization-Functional Class (WHO-FC) III and IV, hemodynamic complications, deaths, major bleeding events and infections after heart surgery than the other groups. A “high” PH probability was associated with reduced right ventricular systolic function, as measured by the fractional area change (FAC), but not with the tricuspid annular plane systolic excursion (TAPSE). Conclusion: The high PH probability as evaluated by the ESC PH echocardiographic probability model, is associated with increased short- and mid-term mortality and morbidity and reduced right ventricular systolic function after cardiac surgery, Thus, additional echocardiographic parameters assessing PH probability are valuable tools to stratify risk in patients undergoing cardiac surgery
Miniaturized extracorporeal circulation versus off-pump coronary artery bypass grafting: A meta-analysis of randomized controlled trials
Get PDFBackground: Controversies exist whether off-pump coronary artery bypass (OPCAB) is superior to miniaturized extracorporeal circulation (MECC) in reducing deleterious effects of cardiopulmonary bypass as only a number of smaller randomized controlled trials (RCT) currently provide a limited evidence base. The main purpose of conducting the present meta-analysis was to overcome the expected low power in RCTs in an attempt to establish whether MECC is comparable to OPCAB.Methods: A MEDLINE/PubMed search was conducted to identify eligible RCTs. A pooled summary effect estimate was calculated by means of Mantel-Haenszel method.Results: The search yielded 7 RCTs included in this meta-analysis enrolling 271 patients in the OPCAB group and 279 in the MECC group. The OPCAB and MECC groups were comparable in terms of incidence of in-hospital mortality (Risk Difference [RD] 0.01; 95%CI -0.02, 0.03; P = 0.55; I-2 = 0%), stroke (RD -0.01; 95%CI -0.05, 0.04; P = 0.69; I-2 = 0%), need for renal replacement therapy (RD 0.00; -0.06, 0.06; P = 1; I-2 = 0%), postoperative atrial fibrillation (RD -0.03; -0.17, 0.10; P = 0.64; I-2 = 0%), re-exploration for bleeding (RD -0.01; 95%CI -0.03, 0.02; P = 0.65; I-2 = 0%), transfusion rate (RD -0.01; 95%CI -0.03, 0.02; P = 0.65; I-2 = 0%) and the amount of blood loss (weighted mean difference -25 mL; 95%CI -71, 21; P = 0.28; I-2 = 0%).Conclusions: Using a meta-analytic approach, MECC achieves clinical results comparable to OPCAB including postoperative blood loss and blood transfusion requirement. On the basis of our findings, MECC should be considered as a valid alternative to OPCAB in order to reduce surgical morbidity of conventional cardiopulmonary bypass. (C) 2015 Surgical Associates Ltd. Published by Elsevier Ltd. All rights reserved
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