1,720,970 research outputs found
Accessory mitral valve leaflet in an adult with coronary artery disease
No full textAccessory mitral valve leaflet is a very rare cause of left ventricular outflow tract obstruction. We report a patient presenting this cardiac abnormality who undergone cardiac surgery. A 60-year-old man, presented coronary artery disease and moderate left ventricular tract obstruction due to accessory mitral valve leaflet. The accessory mitral valve leaflet had the typical morphology of a parachute-shaped attached partially to the anterior mitral valve leaflet, with chordae tendinae attached to: 1) an accessory papillary muscle inserted at the free-wall closed to the apex; 2) interconnected with the chordae tendinae of the anterior mitral valve leaflet; 3) a second accessory papillary muscle inserted to the interventricular septum. He underwent successful coronary revascularization of 2 vessels and accessory leaflet excision. A review of 21 cases with accessory mitral valve leaflet is reported
Undergoing cardiopulmonary bypass using enoxaparin only during a cardiac transplantation procedure
No full textThe use of enoxaparin as a replacement drug to standard heparin, for anticoagulation during extracorporeal circulation, in patients with heparin-induced thrombocytopenia, is still very limited. Enoxaparin significantly reduces thrombin formation and activity during cardiopulmonary bypass. The prolonged circulating rate, slow elimination rate and non-total reversion of enoxaparin by protamine can induce important postoperative bleeding. We are describing the first case of cardiac transplantation where enoxaparin was used as a replacement drug to standard heparin. (C) 2000 Elsevier Science B.V. All rights reserved
Emergency management of spontaneous coronary artery dissection
No full textSix cases of spontaneous coronary arteries dissection are reported. in one patient, triple vessel spontaneous coronary artery dissection was identified. Another patient presented spontaneous left main coronary artery dissection. In one case we found the spontaneous dissection of the left anterior descending artery associated with distal aortic arch dissection. These conditions are very rare and may present a surgical dilemma. Causative factors and underlying pathology are clarified. Prompt diagnosis and surgical intervention is safe and effective. Early recognition of left main coronary artery dissection or three-vessel dissection is essential because urgent coronary artery bypass grafting may be life saving
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
Postoperative outcome in patients with accessory mitral valve tissue.
No full textAccessory mitral valve tissue (AcMVT) is a rare congenital malformation causing left ventricular outflow tract obstruction (LVOTO). The analysis of various published reports reveals 90 patients presenting with AcMVT, ranging in age from newborns to 77 years old. Severe LVOTO is present in most cases, though mild LVOTO was found in 15 patients (16.7%), and 3 other patients (3.3%) presented with no LVOTO. In our practice, we found this anomaly in 5 patients; one presenting with severe LVOTO, two with mild LVOTO, and another who developed moderate LVOTO after a myocardial infarction episode. 68 patients (75.5%) underwent cardiac surgery, with a postoperative mortality of 6 (8.9%). Postoperatively, a residual mild gradient across the left ventricular outflow tract was identified in 9 patients (13.2%). Nine other patients (13.2%) required reoperation due to severe LVOTO. Mild-to-moderate postoperative mitral or aortic valve regurgitation was found in 7 (10.3%) and 5 (7.3%) patients, respectively. Based on reported intraoperative findings, we have classified this anomaly as Type I-FIXED TYPE (A - nodular, B - Membranous), Type II-Mobile type (A - Pedunculated, B - leaflet-like). Type IIB is divided into 1) rudimentary chordae and 2) developed chordae. Based in our own experience and after the analysis of various reports, we conclude that patients with AcMVT causing LVOTO may undergo safe mass excision with acceptable postoperative mortality and morbidity. The removal of the AcMVT should in no way compromise mitral valve function, and its excision should be made subject to careful evaluation of the surrounding structures
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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