1,720,967 research outputs found
Predictive value of noninvasive evaluation by exercise echocardiography and BNP measurement for early identification of pulmonary arterial hypertension in patients affected by systemic sclerosis: 5 years follow-up
Get PDFBackground. Systemic Sclerosis (SSc) is a chronic multisystem disease characterized by fibrosis of the skin and internal organs, microangiopathy and autoimmune disturbance. Pulmonary arterial hypertension (PAH) is one of the most severe complications of the disease, carrying a poor prognosis. Because of the aspecificity of the symptoms, diagnosis is often made when the disease is in an advanced stage and the pulmonary vascular bed involvement is already severe. For this reason it is essential to develop suitable screening tools to early detect the pathology, providing an appropriate therapy, that could improve the prognosis.
Aim of the study. To evaluate the pulmonary arterial systolic pressure (PAsP) during exercise echocardiography in a group of asymptomatic or mildly symptomatic patients affected to SSc. Patients were then submitted to a medium-long term follow-up performing a resting echocardiogram to evaluate the development of pulmonary hypertension, defining the predictive value of the exercise echocardiography to early identify such complication.
Material and methods. 40 patients affected by SSc (33 females and 7 males) with NYHA functional class I and II and with normal PAsP at rest, underwent exercise echocardiography. Resting and exercise PAsP values were estimated through measurement of tricuspidal regurgitant jet velocity by Doppler, considering values of exercise PAsP ≥ 48 mmHg to be pathological. We also analysed resting and exercise hemodynamic parameters, clinical characteristics of the patients and of the underlying rheumatic disease as well as measurement of resting and exercise BNP values. A medium-long term follow-up was done (5,1 ± 0,4 years), performing a clinical and resting echocardiographic evaluation to detect the development of pulmonary hypertension.
Results. Resting PAsP values were 26,5 ± 4,6 mmHg, reaching values of 45,1 ± 14,2 mmHg during exercise (p 0,00), with a mean increase of 18,7 ± 11,9 mmHg. 25 patients (62,5%) had normal values of exercise PAsP (group A), whereas 15 patients (37,5%), all women, had exercise-induced altered pulmonary vasoreactivity (group B). Comparing group A and B, we found significant differences regarding both resting and exercise PAsP values (respectively p 0,007 and p 0,00), but also regarding exercise BNP values and the variation between resting and exercise BNP (respectively p 0,02 and p 0,001). Out of 40 initial patients, 2 patients died because of extracardiac causes, and 2 patients were lost; therefore 36 patients were followed for a mean time of 5,1 ± 0,4 years. Data from follow-up showed mean resting PAsP of 29,67 ± 7,4 mmHg. 5 patients, belonging to group B, presented pathological resting PAsP values: 3 of these patients had PAsP values suggestive for the diagnosis of possible pulmonary arterial hypertension (PAsP > 37 mmHg), 2 patients had PAsP values suggestive for the diagnosis of probable PAH (PAsP > 50 mmHg). None of the group A patients developed pathological PAsP values at follow-up.
Conclusions. Prevalence of exercise-induced altered pulmonary vasoreactivity, detected by exercise echocardiography, is high in patients affected by SSc.
Such patients had a higher risk for developing pulmonary hypertension at medium- to long- term follow-up. Exercise echocardiography, associated with BNP testing, has been demonstrated to be useful to identify SSc patients presenting an abnormal increase of PAsP during exercise that could, far away, develop PAH
Microbubbles contrast inside the cyst: a pathognomonic sign of mitral valve blood cyst
No full textWe report a case of giant blood cyst originating from the anterior mitral valve leaflet in an 18-year-old white girl. Contrast real-time transthoracic echocardiogram showed the presence of microbubbles inside the cystic cavity during diastole, confirming the presence of blood passage between the ventricular cavity and the cyst lumen and suggesting that this is a pathognomonic sign of the presence of a blood cyst. Although, in previous cases, contrast microbubbles inside the cyst have been described during systole, we report the presence of microbubbles during diastole
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
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
- …
