1,720,960 research outputs found
Systemic-pulmonary arterial supply in pulmonary atresia with ventricular septal defect: postmortem angiograms and histologic survey.
No full textPostmortem angiographic and histologic studies of the pulmonary arterial circulation were performed in a patient with pulmonary atresia and a ventricular septal defect. While the left lung was supplied by a closing ductus arteriosus, the right lung was supplied by two systemic pulmonary arteries arising from the descending aorta. The examination disclosed that systemic pulmonary arteries lead into the pulmonary vascular bed and the capillaries of the alveolar walls. According to these observations, such collateral circulation is to be considered functional. The pulmonary vascular bed, supplied by the ductus arteriosus and the stenotic systemic pulmonary artery, showed a thin muscular layer in the small arteries and arterioles. On the contrary, medial hypertrophy and severe intimal proliferation were observed in the pulmonary segments perfused by the other large unobstructed systemic pulmonary artery, thus proving that asymmetric pulmonary vascular disease may complicate the natural history of this malformation
Giant blood cyst of tricuspid valve. Successful excision in an infant.
No full textA case of a giant blood-filled cyst of the tricuspid valve in described in a 4-month-old infant. The cyst caused obstruction of the right ventricular inflow and outflow tracts and a right-to-left shunt; it was successfully removed at open heart surgery. Pitfalls in differential diagnosis and the pathogenesis are discussed
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
Left atrial radiofrequency ablation during cardiac surgery in patients with atrial fibrillation
No full textVariations 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
[Evaluation of clinical data and effort test in patients with angina pectoris: an approach to a multivariate analysis in different groups].
No full textOne-hundred and eighty-nine patients who underwent cardiac catheterization for suspected ischemic heart disease were assigned to four different groups depending on the number of diseased vessels (0, 1, 2, 3), the dominant artery and the presence of left main coronary stenosis. Among the 45 parameters obtained from history, physical examination, E.C.G., and exercise test multivariate analysis identified (positive stress test, maximal systolic blood pressure, documented myocardial infarction, maximal heart rate, ipercholesterolemia, lateral myocardial infarction, angina during stress test) that were statistically significant. A score system was devised on the basis of the summed-up value of the seven parameters. When the patients were assigned, according to the score, to one of the previously mentioned 4 groups, the classification proved to be correct in 54% of the cases. When we divided the patients in two groups with or without coronary artery disease so that the attribution turned out to be correct in 92% of the cases (sensitivity 94%, specificity 77%), whereas when based on ST segment depression only, the classification was correct in 85% of the cases (sensitivity 84%, specificity 88%)
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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