1,720,966 research outputs found
Transthyretin amyloidosis in aortic stenosis: clinical and therapeutic implications
No full textAbout one in seven elderly patients with severe calcific aortic stenosis (AS) also have ATTR amyloid cardiomyopathy (AC-TTR). The reasons for this close association are not fully known, but the two entities are not only related by common epidemiology. For example, it is possible to hypothesize that an amyloidotic infiltration of the aortic valve, even partial, can act as a trigger for the development of endothelial damage and subsequent calcification. Another hypothesis is the increased myocardial strain induced by AS may locally favour the process of amyloidogenesis and tissue infiltration. In a patient with AS, the coexistence of AC-TTR can be suspected by careful analysis of the echocardiogram and the ECG, especially if a clinical history of carpal tunnel syndrome coexists. Bone tracer scintigraphy allows a diagnosis of certainty. Recently, several studies have evaluated the prognostic implications of the coexistence of the two entities in candidates for percutaneous aortic valve replacement, showing how amyloidosis would not significantly impact the results of the procedure, but would only be associated with a greater risk of distant heart failure. In patients with AS associated with AC-TTR, valve replacement should not be ruled out in the presence of the usual clinical-haemodynamic indications
Unsolved Questions in the Revascularization of Older Myocardial Infarction Patients with Multivessel Disease
No full textBackground: In cardiology, the global phenomenon of population ageing poses new major challenges, ranging from more comorbid and frail patients to the presence of complex, calcified and multiple coronary lesions. Considering that elderly patients are under-represented in randomized clinical trials (RCT), the aim of this systematic review is to summarize the current knowledge on the revascularization of the elderly patient with myocardial infarction and multivessel coronary artery disease. Methods: A systematic review following PRISMA guidelines has been performed. The search was conducted on Pubmed (Medline), Cochrane library, Google Scholar and Biomed Central databases between January and February 2022. We selected the articles focusing on patients hospitalized for myocardial infarction (MI) with multivessel disease and aged 75 years or older. A total of 36 studies have been included. Results: Multivessel coronary artery disease is present in around 50–60% of older patients with MI. The in-hospital mortality rate of patients older than 75 years is double compared to their younger counterpart, and the most prevalent complications after revascularization are bleeding and renal failure. In the treatment of patients with ST elevation MI (STEMI), primary percutaneous coronary intervention should be the first choice over fibrinolysis. However, it is not clear whether this population would benefit from complete revascularization or not. In patients with non-ST elevation MI (NSTEMI), an invasive approach with either percutaneous coronary intervention or coronary artery bypass graft may be chosen, but a conservative strategy is also accepted. There are no data from large trials about the comparison of possible revascularization strategies in NSTEMI patients. Conclusions: This systematic review shows that this field of research lacks randomized clinical trials to guide revascularization strategy in older STEMI or NSTEMI patients with MI. New results are expected from ongoing trials
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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