1,720,963 research outputs found
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
Single-centre experience and preliminary Results of intravascular ultrasound in endovascular aneurysm repair
No full textIntravascular ultrasound (IVUS) has been introduced as diagnostic adjunct to provide new insights in the diagnosis and therapy of vascular disease. Herein we compared the outcomes of conventional endovascular aneurysm repair (EVAR) and EVAR with IVUS in patients presenting infrarenal abdominal aortic aneurysm using a propensity-matched cohort.
Methods
From May 2013 to August 2017, 221 patients were retrospectively analysed. 122 patients were eligible for inclusion and underwent to propensity score matching. Perioperative mortality and morbidity, renal function impairment, endoleak incidence, mean contrast medium usage, operative time, radiation exposure [including fluoroscopy time, dose-area product (DAP) and digital subtraction angiography (DSA) runs] , survival and freedom from reintervention were the outcomes measured.
Results
After matching, 52 patients were included, 26 in the conventional EVAR group and 26 in the EVAR with IVUS group. No perioperative mortality or type I/III endoleak were registered. One perioperative lymphatic fistula and one iliac limb occlusion were observed. In the EVAR with IVUS group, a significant reduction of contrast medium (92[vs51±17] vs 51[20-68] ml; P=.003) and radiation exposure including fluoroscopy time (12 [9-16] vs 20 [12-25] minutes; P=.001); DAP (15 [9-21] vs 32 [16-44] G*cm 2 ; P=.002); DSA runs (2 [1-3] vs 3 [2-4]; P=.04)was reported. No differences were observed in term of glomerular filtration rate (86[45-121] vs 90[38-117] ml/min; P=.14) and operation time (176[124-210] vs179[120-210]; P=.48). Survival at 36 months was 93% for standard EVAR and 92% for EVAR with IVUS (P=.845). Freedom from reintervention at 36 months was 85.5% in both groups (P=.834).
Conclusions
In this preliminary experience, the use of IVUS during EVAR was feasible with no registered post-operative complications. A significant reduction of contrast medium usage and radiation exposure was observer with the use of IVUS. The IVUS is an adjunctive tool to consider in the vascular surgeon armamentarium especially in centres where advanced radiological tools of imaging fusion are not available
Patologia aterosclerotica complessa degli arti inferiori: attualità nel trattamento
No full textNessun
Approccio vascolare nell’ischemia mesenterica cronica
No full textApproccio vascolare nell’ischemia mesenterica cronic
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
- …
