1,720,958 research outputs found
Heart failure due to right ventricular apical pacing: the importance of flow patterns
No full textIn patients receiving permanent cardiac electrical stimulation, a high burden of apical right ventricular pacing is associated with an increased incidence of heart failure. Despite the large body of electrocardiographic, echocardiographic, and pathological data, mechanisms underlying this serious complication are not fully understood. Moreover, the empirical use of alternative right ventricular pacing sites, both in the experimental and in the clinical setting, has not provided better results in terms of clinical outcome. Recent data derived by echocardiographic particle image velocimetry of intracardiac flows have shown abnormal flow patterns in patients with dyssynchrony of left ventricular wall contraction, and the reversion to normal flow dynamics after successful electrical cardiac resynchronization therapy. This suggests that a normal intraventricular flow pattern is strongly dependent on the highly coordinated contraction of the ventricular wall segments and that an abnormal sequence of wall contraction may trigger the development of overt heart failure. This review summarizes the state of the art on this topic, highlighting postulated underlying basic mechanisms linking abnormal flow with the development of pacing-induced heart failure. This research line suggests the importance of studying intraventricular fluid dynamics as a new powerful tool for a more complete understanding of mechanisms involved, and ultimately to prevent pacing-related heart failure
Therapeutic strategies aiming at the reduction of the antiplatelet intensity should not overlook the ischemic risk in patients with coronary syndromes
No full textDe-escalation of dual antiplatelet therapy (DAPT) is gaining traction as a strategy to reduce bleeding risks while ensuring ischemic outcomes. Undiscriminating de-escalation, notably in patients with high ischemic risk, might expose them to major adverse cardiac events. Platelet function and genetic tests are emerging tools to guide de-escalation, but both present specific drawbacks. Recent meta-analyses have aimed to consolidate the findings of individual trials to provide clearer insights. Yet, limitations remain for patients with concomitant high bleeding and ischemic risks. These high-risk patients are frequently underrepresented in clinical trials, and, therefore, currently available guidelines lack evidence-based recommendations for this subset. While DAPT de-escalation strategies hold promise, the choice of approach, whether clinically or assay-guided, remains complex and should be individualized
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
Clot-in-transit and pulmonary embolism: an urgent call for awareness and action
No full textPatients with acute pulmonary embolism (PE) have a wide spectrum of clinical presentations, from incidental findings to sudden cardiac death. Management and treatment recommendations in currently available guidelines vary according to patient risk and haemodynamic profile. A clot-in-transit (CiT) in the right heart chambers may be occasionally identified and is, therefore, an under-recognised but challenging condition, often preceding an abrupt clinical deterioration, and associated with increased mortality. Data on the detection of a CiT are sparse but consistent in attributing negative prognostic relevance, and therefore the presence of CiT should be systematically investigated and recorded in the setting of PE. In this review, the challenges related to the identification of a CiT are highlighted. Here, we propose an algorithm where the role of the Pulmonary Embolism Response Team (PERT) is reinforced. The PERT should convene once the CiT is suspected, to define the timeline for the diagnostic steps and subsequent management on a case-by-case basis. A patient with PE and CiT requires close bedside monitoring and rapid escalation therapy in case of clinical deterioration. Beyond anticoagulation alone, more aggressive strategies can be considered, including systemic thrombolysis, surgical pulmonary embolectomy and the currently emerging catheter-directed therapies
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