1,720,954 research outputs found
Role of ACE-inhibitors in preventing atrial fibrillation relapses in normotensive patients
No full textLa fibrillazione atriale (FA) rappresenta l’aritmia cardiaca più frequente ed un rilevante problema sanitario, in considerazione delle elevate percentuali di mortalità e morbilità ad essa legate. La FA riconosce molteplici cause di innesco: la più diffusa, nel mondo occidentale, è l’ipertensione arteriosa. L’aumento dei valori pressori determina modificazioni emodinamiche che hanno effetto diretto sulla funzione e sulla struttura del ventricolo e dell’atrio sinistro. Il sistema renina angiotensina aldosterone (RAAS) svolge un ruolo importante nella regolazione del volume ematico circolante e delle resistenze vascolari sistemiche. Studi recenti hanno dimostrato che il RAAS ha, inoltre, effetti favorevoli nel modulare la contrattilità e le caratteristiche anatomiche del ventricolo e dell’atrio sinistro.
Ricerche sperimentali e cliniche hanno evidenziato che gliACE-inibitori e i bloccanti dei recettori dell’angiotensina II sono efficaci nel prevenire la fibrillazione atriale nei pazienti con ipertensione arteriosa e/o altre cardiopatie. In una recente indagine abbiamo
dimostrato l’efficacia del ramipril nel prevenire le recidive di FA nei pazienti con FA isolata (fibrillazione atriale in assenza di segni clinici e ecocardiografici indicativi di malattie cardiache, polmonari o endocrine), indipendentemente dall’effetto sull’anatomia cardiaca
documentabile con l’ecocardiografia colorDoppler. In questo articolo discutiamo 1) il ruolo del ramipril nel prevenire le recidive di FA nei pazienti con FA isolata; 2) analizziamo i potenziali meccanismi di azione di questo farmaco; 3) valutiamo la possibilità di considerare la FA isolata come un marker di un danno d’organo subclinico in soggetti con valori pressori 130-139mmHg (pre-ipertensione secondo la classificazione del JNC-7 Report; e/o valori pressori normali alti in quella delle linee guida ESC/ESH 2007)
Prevention of recurrent lone atrial fibrillation by the angiotensin-II converting enzyme inhibitor ramipril in normotensive patients
Get PDFObjectives. The aim of the present study was to verify whether angiotensin-II converting enzyme (ACE) inhibition is also effective in preventing relapses of lone atrial fibrillation (LAF), that is, in the absence of hypertension and/or heart disease.
Background. Several studies have shown that ACE inhibitors are effective in preventing atrial fibrillation (AF) relapses in patients with arterial hypertension or several forms of heart disease, that is, in the presence of clinical conditions that are recognized as causing a higher risk of atrial arrhythmias.
Methods. Sixty-two patients admitted to the emergency department of our institution for a first-ever episode of LAF were enrolled in the study after excluding the presence of cardiac or extracardiac conditions known to be associated
with an increased risk of AF, by medical history, physical examination, complete echocardiographic study, and the evaluation of blood pressure, thyroid function, urinary catecholamines, serum electrolytes, blood glucose, red blood cell count, and arterial blood gases. After cardioversion to sinus rhythm by intravenous propafenone, patients were randomized to either ramipril 5 mg/day (n = 31) or placebo (n = 31). Holter monitoring and clinical examination were performed every 3 months.
Results. After a 3-year follow-up, AF relapses were observed in 3 patients treated with ramipril and in 10 patients allo-
cated to placebo (p < 0.03, Kaplan-Meier, log-rank test). During follow-up, none of the patients developed arterial hypertension or other cardiac or extracardiac condition known to be associated with increased risk of AF, that is, in all patients the diagnosis of LAF was confirmed.
Conclusions. Ramipril is effective in preventing relapses of LAF
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
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