1,720,958 research outputs found
Evaluation of left atrial appendage function and thrombi in patients with atrial fibrillation: from transthoracic to real time 3D transesophageal echocardiography
No full textThe detection of embolic sources in patients with atrial fibrillation (AF) is important to guide anticoagulant therapy. Two-dimensional transesophageal echocardiography (TEE) is the gold standard to study left atrial appendage (LAA) anatomy and morphology, despite some false-positive diagnosis. We hypothesized that real time 3D TEE (RT3DTEE) is superior to 2DTEE in detecting and/or excluding LAA thrombi. We studied 93 patients with non-valvular AF (60 males, age = 67.1 ± 14.2 years) referred for electric cardioversion with transthoracic, 2DTEE and RT3DTEE. Before cardioversion, TTE allowed a confident measurement of emptying velocity of LAA (LAAeV) only in 59/93 patients (63%). On the contrary a good quality TEE LAAeV was obtained in all patients with 49/93 (53%) dysfunctional LAA (LAAeV < 40 cm/s). A subgroup of 5 patients (7.2% of the 69 effective cardioversion) presented a persistent dysfunction after cardioversion (with LAAeV values of <40 cm/s on the TEE post-CV). TEE allowed to observe a bilobed shape in 45 patients (48.4%) and three lobes in 22 patients (23.7%). In addition, besides to several additional findings, 2DTEE managed to detect thrombi with certainty in 8/93 patients (8.6%). In other 5 cases with diagnostic doubts for thrombi with 2DTEE (5/93 patients: 5.4%), the addition of the RT3DTEE mode allowed to discriminate with certainty the presence of just pectinate muscles in 4 patients RT3DTEE in patients with AF at risk of embolism is feasible, accurate and showed an additional diagnostic capability in the differential diagnosis of selected cases with suspected LAA thrombi
[Vitamin D deficiency and cardiovascular diseases]
No full textVitamin D deficiency is a condition that affects a high percentage of individuals of all ages. Considerable attention has been paid recently to the possible role of deficiency of this vitamin in the development of several chronic diseases, including cardiovascular and metabolic diseases. In particular, vitamin D deficiency is associated with an increase in conditions such as obesity, insulin-resistance, hypertension, diabetes, and an increased risk of death from these pathologies. There is also a significant correlation with mortality for major cardiovascular events such as heart failure, myocardial infarction, sudden cardiac death, stroke, atrial fibrillation, and peripheral vascular disease. The pathophysiological mechanisms of these correlations are yet to be determined, but hyperactivity of the renin-angiotensin-aldosterone system seems to play a leading role. The role of therapy with vitamin D supplements in improving cardiovascular outcome in patients with low levels of vitamin D remains to be determined
Fulminant Peripartum myocarditis associated with sudden cardiac death: a case report
No full textMyocarditis is an inflammatory disease of myocardium, associated with nonischemic necrosis and degeneration of myocytes. Although the clinical course is rapid, myocarditis can lead to dilated cardiomyopathy with chambers dilatation and ventricular dysfunction. The pathophysiology of myocarditis in humans is not completely understood. There are several etiological agents implicated, mainly viral agents. The clinical presentation is extremely various, with nonspecific systemic symptoms until sudden death. The great variability of symptoms makes the diagnosis, therefore, extremely difficult. We report the case of a 40-year-old woman who developed, after childbirth, hyperthermia associated with neck and left arm pain; initially treated with acetaminophen, without any benefit, the young woman, after few days, died suddenly. The autopsy documented the presence of edematous lungs and enlarged and congested liver. The microbiological tests performed 4 days after death were negative. The heart was normal in shape and volume; a section of the left ventricle wall showed subendocardial discromic areas histologically characterized by multifocal perivascular and interstitial inflammatory infiltrates. These infiltrates consisted mainly of neutrophils with eosinophil component associated with myocyte necrosis and hemorrhagic interstitial infiltration
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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