1,720,962 research outputs found
Assessment of carotid elasticity during exercise: a reproducibility study.
No full textThe study aimed to evaluate the reproducibility of carotid elasticity during exercise. Eighteen healthy volunteers (nine males, age 34 ± 3 years, BMI 22 ± 6 kg/m(2)) underwent maximal exercise testing on a graded semi-supine cycle ergometer in two different sessions 3 days apart. Ultrasound B-mode image sequences of the right common carotid were acquired at different steps and analyzed by an automatic system; pressures were estimated by tonometry. Compliance (CC) and distensibility (DC) were significantly decreased at exercise peak and in the first recovery minute (CC from 1.6 ± 0.8 to 1 ± 0.6 mm^(2)/KPa, DC from 56.2 ± 25.3 to 34.5 ± 20 10^(-3)/KPa, p < 0.05). For the whole examination, intraclass coefficient was 0.780 for CC and 0.694 for DC. Mean coefficient of variation was maximum at peak exercise (CC = 19 ± 6%, DC = 24 ± 15%), but at first minute of recovery it was comparable to resting values (CC = 12 ± 9%, DC = 12 ± 11%). When designing future studies, acquisitions during first recovery minute might be preferred to peak measure
Patterns of left ventricular remodeling in chronic heart failure: Prevalence and prognostic implications
No full textAbstract
BACKGROUND AND AIM:
Many descriptors of left ventricular (LV) remodeling have important prognostic implications in patients with chronic systolic heart failure (HF). We sought to assess the prognostic value of the combination of increased LV mass with a disproportion between wall thickness and internal diameter.
METHODS AND PATIENTS:
Patients (n = 536) with chronic HF, ejection fraction 91 mL/m(2), classified according to LV mass index and relative wall thickness (RWT), were followed up for 33 ± 21 months. Ventricular mass was determined using a standard M-mode echocardiographic method. Relative wall thickness was defined as the ratio of (sum of interventricular septum thickness in diastole + posterior wall thickness in diastole)/LV end-diastolic diameter.
RESULTS:
Prevalence of the pattern of increased LV mass index, defined as LV mass index >148 g/m(2) in men and >122 g/m(2) in women, and decreased RWT (70 years (P 2 (P < .0001), increased LV mass index, and decreased RWT (P = .003), E wave deceleration time ≤140 ms (P = .005), and male gender (P = .025). Patients with increased LV mass index and decreased RWT had a worse survival (33%) than patients with less LV mass index and normal to reduced RWT (log-rank 23.92; P < .0001). Comparisons of Cox models showed that the combination of increased mass index and decreased RWT added prognostic value to a model that included ejection fraction and end-systolic volume index.
CONCLUSION:
In patients with systolic HF, an independent and incremental risk of adverse outcome was associated with increased mass index and decreased RWT
Valvulo-arterial impedance (Zva): a new index of global haemodynamic load in the evaluation of severe aortic stenosis treated by transcutaneous aortic valve prosthetic implantation (Corevalve)
No full textGoing 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
Prognostic value of valvulo-arterial impedance (Zva) in patients with symptomatic severe aortic valve stenosis undergoing to transcatheter aortic-valve implantation (CoreValve)
No full textVariations 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
GLOBAL 2D STRAIN AS NEW INDEX OF LEFT VENTRICULAR FUNCTION IN OBESITY BEFORE AND AFTER BARIATRIC SURGERY
No full textAppropriate 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
- …
