1,720,973 research outputs found
Stereotactic ventricular tachycardia radioablation aided by CT-channels analysis in a patient with inaccessible transmural substrate
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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
Imaging-guided ventricular tachycardia ablation: preliminary experience from a multicenter clinical trial
No full textRadiofrequency catheter ablation is a safe and effective treatment for scar-related ventricular arrhythmias. Preliminary studies have shown that real time integration of late gadolinium enhancement magnetic resonance images (LGE-CMR) with electroanatomical mapping (EAM) systems can lead to improved procedural efficacy, efficiency and safety.
We present the preliminary results of a prespecified interim analysis of the VOYAGE trial, a prospective, randomized, multicenter controlled open label study aimed at comparing in terms of efficacy, efficiency and safety a CMR aided/guided approach to standard EAM-guided ventricular tachycardia (VT) ablation.
Patients with an ICD or with ICD implantation expected within 1 month with structural left ventricle heart disease and scar-related VT were randomized to a CMR-guided or a CMR-aided approach with LGE-CMR image post-processing performed with an artificial intelligence powered software (ADAS3D), while subjects unsuitable for imaging or with image quality deemed not sufficient for postprocessing were allocated to standard of care ablation.
Primary endpoint was defined as VT recurrence within 12-months follow up (either sustained or requiring ICD therapy), with a 1-month blanking period. Secondary endpoints included procedural efficiency, safety and impact on quality of life
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
Efficacia e sicurezza dell'ablazione della Fibrillazione Atriale: follow up a lungo termine in un centro ad alto volume di procedure
No full textBackground
La Fibrillazione Atriale è una aritmia ad elevata prevalenza e incidenza, con una significativa morbidità e mortalità. L’introduzione dell’ablazione transcatetere ha permesso di migliorare la cura dei pazienti affetti rispetto alla terapia farmacologica, e negli ultimi anni abbiamo assistito a un progressivo miglioramento dei risultati di tale trattamento interventistico.
Obiettivi
Lo studio si propone di valutare l’efficacia e la sicurezza dell’ablazione transcatetere della Fibrillazione Atriale presso un singolo centro ad alto volume di procedure. Abbiamo definito come end point primario l’efficacia a lungo termine e la sicurezza a 30 giorni, valutando i fattori preoperatori e intraoperatori predittivi sull’efficacia della procedura stessa. Mentre come end point secondari sono stati valutati l’efficacia a 12 mesi, dopo procedure multiple, l’impatto delle procedure redo sul successo a lungo termine e l’impatto di eventuali lesioni aggiuntive extrapolmonari sull’efficacia dell’ablazione delle forme persistenti di aritmia.
Materiali e metodi
Sono stati arruolati 669 pazienti consecutivi (489 uomini, 180 donne; età media di 59,12±10,47) sottoposti a procedura di ablazione transcatetere di Fibrillazione Atriale da Gennaio 2010 a Dicembre 2015. Il follow up (media di 958 giorni) è disponibile per 503 pazienti (75%). La valutazione dell’outcome procedurale è stata effettuata esclusivamente sui pazienti sottoposti a prima procedura nella vita (pazienti naive), escludendo le recidive comparse nel periodo di 90 giorni dopo l’intervento (blanking period).
Risultati
L’efficacia globale della procedura è stata del 72,84% a 12 mesi e del 55,58% a lungo termine, con un risultato migliore nelle forme parossistiche rispetto alle forme persistenti (efficacia a 12 mesi: 77,24% vs. 65,60%, p=0,0013; efficacia a lungo termine: 60,96% vs. 45,32%, p=0,002). Abbiamo osservato un trend di progressivo miglioramento nell’efficacia procedurale con, nell’ultimo anno di osservazione un risultato pari all’81,72% di efficacia globale e dell’85,48% per le forme parossistiche. L’1,5% dei pazienti ha sviluppato complicanze maggiori, decesso correlato alla procedura caso di mortalità (fistola atrioesofagea; 0,15%).
Sono risultati predittivi di efficacia a lungo termine: l’assenza di comorbidità (p=0,002), la presenza di ritmo sinusale a inizio procedura (p=0,002), l’uso di un catetere con sensore di contatto (p<0,001), la risoluzione dell’aritmia durante l’ablazione (p=0,03) l’esecuzione di lesioni aggiuntive in istmo destro nelle forme parossistiche (p=0,001).
Predittori di inefficacia sono risultati: l’ipertensione arteriosa (p=0,007), la dilatazione atriale sinistra (p<0,001), l’esecuzione di cardioversione elettrica intraprocedurale (p<0,001).
Conclusioni
L’ablazione transcatetere della Fibrillazione Atriale è una procedura sicura e complessivamente efficace, specialmente per le forme parossistiche. Una singola procedura risulta sufficiente nella maggior parte di tali pazienti (successo di circa l’80% a 12 mesi se utilizzati cateteri a sensore di contatto), con ulteriore aumento del 10% di efficacia con la prima procedura di redo. L’ablazione delle forme persistenti, e in particolare long standing, presenta ancora risultati non soddisfacenti, sebbene l’evoluzione tecnologica dei sistemi di mappaggio e di ablazione potrebbe in futuro garantire un’efficacia maggiore anche in queste forme di aritmia
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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