1,721,113 research outputs found
Right ventricular/pulmonary artery coupling in patients with heart failure with preserved ejection fraction. a clue for pulmonary hypertension
Full text linkpulmonary hypertension (PH) in left heart disease is a common condition, primarily caused by backward transmission of an elevated left atrial pressure (this hemodynamic picture is defined as isolated postcapillary PH). Through poorly understood mechanisms, the increase in pulmonary venous pressure
may cause a remodeling of the small pulmonary arteries with the development of a precapillary component that identifies a combined pre-post capillary PH. As pulmonary vascular resistance increases, right ventricular (RV) adaptation to the increased afterload may fail, and abnormal RV systolic function develops during exercise and at rest. The development of PH in patients affected by heart failure has a relevant prognostic impact, increasing morbidity and mortality; and, in particular, when associated with RV dysfunction, it represents an adverse clinical turning point in the history of the diseas
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
Echocardiography and Heart Failure: A Glimpse of the Right Heart
No full textThe catastrophic consequences for patients in the settings of certain clinical conditions such as acute right ventricular infarction or massive pulmonary embolism with right heart failure illustrate the essential role that the right ventricle plays in sustaining life. With the development of more sophisticated diagnostic imaging technologies at the end of the last century and the dawn of this century, the importance of the right ventricle has been clearly demonstrated. The continued and evolving nature of our understanding of the right ventricle was emphasized in 2006, when the National Heart, Blood, and Lung Institute formed a working group focused on developing a better understanding of the right ventricle in both healthy and disease states. The objective of this review paper is to examine the right ventricle structure and function and describe the role of echocardiography in the evaluation of the right ventricle and right heart failure. Special focus will be on echocardiographic images and major society guidelines.
2014, Wiley Periodicals, Inc
Gaps of evidence in pulmonary arterial hypertension
No full textThe authors discuss the main gas of evidence in the field of diagnosis, risk stratification and therapy of PAH patient
Prognostic impact of diabetes in chronic and acute heart failure
No full textA strong, bidirectional relationship exists between diabetes mellitus (DM) and heart failure (HF) and DM is responsible of the activation of several molecular and pathophysiological mechanisms that may, on the long term, damage the heart. However, the prognostic role of DM in the context of chronic and acute HF is still not yet defined and there are several gaps of evidence in the literature on this topic. These gaps are related to the wide phenotypic heterogeneity of patients with chronic and acute HF and to the concept that not all diabetic patients are the same, but there is the necessity to better characterize the disease and each single patient, also considering the role of other possible comorbidities. The aim of the present review is to summarize the pathophysiological mechanisms subtending the negative effect of DM in HF and analyze the available data exploring the prognostic impact of such comorbidity in both chronic and acute HF
- …
