1,721,196 research outputs found
Balloon pulmonary angioplasty in patients with CTEPH
No full textThe only curative treatment currently available for chronic thromboembolic pulmonary hypertension (CTEPH) is surgical pulmonary endoarterectomy (PEA). However, several patients may have high risk factors for surgery, or a peripheral disease not amenable to surgical treatment; or else a residual pulmonary hypertension after PEA. Balloon pulmonary angioplasty (BPA) was recently developed to offer an alternative treatment for these patients. Extensive data has since confirmed the efficacy and relative safety of this procedure. However, there are several technical issues that have yet to be resolved. In addition, many cardiologists and pneumologists still know very little about the procedure itself and its potential. Exploring the clinical indications and technical aspects of BPA, this book offers a valuable reference guide for all those who would like to introduce or improve a BPA program, and for all those whose work involves treating this complex patient population
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
Diagnosis of Chronic Thromboembolic Pulmonary Hypertension
No full textChronic thromboembolic pulmonary hypertension (CTEPH) is the only potentially curable form of pulmonary hypertension (PH) and a rapid and accurate diagnosis is pivotal for successful treatment. Current guidelines recommend that all patients with suspected CTEPH be referred to an expert centre for an accurate differential diagnosis and evaluation of the best treatment strategy to be performed by a multidisciplinary team. Ventilation/perfusion (V/Q) lung scan remains the screening method of choice; a normal scan rules out CTEPH. Despite the status of high-quality pulmonary angiography as the gold standard, techniques such as computed tomography pulmonary angiography (CTPA) and magnetic resonance imaging (MRI) are increasingly used for characterising the pulmonary vasculature and assessment of operability. Although there is increasing interest in non-invasive haemodynamic evaluation, given the complexity of pathophysiologic changes occurring in CTEPH, right-heart catheterisation (RHC) is still mandatory to confirm the diagnosis of pulmonary arterial hypertension (PAH) and to assess the degree of haemodynamic impairment. This chapter describes the diagnostic workup that is commonly used in clinical practice and recommended in the scientific literature
Metrics for Success of Balloon Pulmonary Angioplasty in Chronic Thromboembolic Pulmonary Hypertension
No full textBalloon pulmonary angioplasty (BPA) has been developed as a compassionate procedure for symptomatic patients with chronic thromboembolic pulmonary hypertension (CTEPH) who are not candidates for pulmonary endarterectomy. With increasing physicians’ expertise, improvement of clinical results, and worldwide diffusion of the technique, definition of treatment goals has become crucial. The efficacy of BPA could be assessed from the patient’s perspective according to clinical endpoints as well as through the evaluation of surrogate endpoints that are known to hold significant prognostic value. The principal objective of BPA should be the stable relief of pulmonary hypertension (PH), with normalization of mean pulmonary artery pressure (<25 mmHg) and pulmonary vascular resistance (PVR). Importantly, clinical outcomes of BPA are the results of multiple-staged procedures, each one addressing several lesions in different lung territories. Hence, definition of metrics for success at a lesion level is a necessary step to guide the BPA procedures. To date, the best targets for BPA at the lesion level are normalization of pulmonary flow grade (PFG = 3) and abrogation of pressure gradient through the lesion (Pd/Pa < 0.8). Patients undergoing BPA represent a heterogeneous group and different target goals could be reasonably set for different patients. The effect of extensive anatomic revascularization beyond normalization of mPAP is under investigation and might be the target for selected patients. Standardization of definitions for efficacy and safety endpoints, in this context, seems necessary. This chapter describes endpoints and metrics for BPA that are commonly used in clinical practice and in the scientific literature
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
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