1,721,085 research outputs found
Multicenter evaluation of a next-generation balloon-expandable transcatheter aortic valve
No full textAbstractBackgroundThe SAPIEN 3 (Edwards Lifesciences Inc., Irvine, California) transcatheter valve incorporates features designed to address the well-known deficiencies of transcatheter aortic valve replacement (TAVR). An ultra–low-profile delivery system facilitates safe, controlled, and accurate implantation and an external seal minimizes paravalvular regurgitation.ObjectivesThe study evaluated whether TAVR with this third-generation valve would be a viable alternative to high- or intermediate-risk surgery for severe aortic stenosis.MethodsThe prospective study enrolled 150 patients at 16 sites in Europe and Canada. Clinical and echocardiographic outcomes were assessed at baseline, post-procedure, and 30 days. New sizing recommendations were developed during the course of the study.ResultsPatients were 83.6 ± 5.0 years of age, with multiple comorbidities reflected by a Society of Thoracic Surgeons score of 7.4 ± 4.5% and logistic EuroSCORE of 21.6 ± 12.3%. A transfemoral approach was chosen in 64.0% and alternative access (transapical/direct aortic) in the remainder. At 30 days, paravalvular regurgitation was none to mild in 96.4% and moderate in 3.5%. No patient had severe regurgitation. Transfemoral implantation was associated with low mortality (2.1%), no disabling stroke (0.0%), and fully percutaneous access and closure in 95.8%. Nontransfemoral alternative access was associated with higher rates of mortality (11.6%) and stroke (5.6%).ConclusionsThis third-generation device addresses major deficiencies of earlier valves in terms of ease of use, accuracy of positioning, and paravalvular sealing. The rates of mortality and stroke with transfemoral access are among the lowest reported and support further evaluation as an alternative to open surgery in intermediate-risk patients. (Safety and Performance Study of the Edwards SAPIEN 3 Transcatheter Heart Valve [SAPIEN3]; NCT01808287
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
Untersuchungen und semiquantitative Symmetrie-Analysen zur Extrazellulärmatrix von Kalbs-Stimmlippen
Full text linkZusammenfassung
Hintergrund und Ziele
Ziel dieser Arbeit war die Analyse der Extrazellulärmatrix (EZM) der Lamina propria von Kalbsstimmlippen. Im ersten Teil der Arbeit wurde die qualitative Zusammensetzung der EZM untersucht. Im zweiten Teil dieser Studie wurde die EZM der Stimmlippen semiquantitativ untersucht, um herauszufinden ob eine symmetrische Verteilung zwischen linker und rechter Seite vorliegt.
Methoden
Diese Arbeit basiert auf histologischen und immunhistochemischen Untersuchungen von 13 paarigen Kalbsstimmlippen. Für den qualitativen Teil wurden zusätzlich Immunfluoreszenz- Färbungen angefertigt. Den semiquantitativen Teil der Arbeit betreffend, wurde die Dichte der angefärbten EZM-Komponenten densitometrisch gemessen und die Differenz zwischen beiden Seiten der Stimmbänder analysiert.
Ergebnisse und Beobachtungen
Im qualitativen Teil der Arbeit fanden die Kollagene I, IV, VI und VII, die Laminin-Ketten α1, α2, α5, β1, β2, β3 und γ1 nähere Betrachtung. Des Weiteren wurde die Verteilung der retikulären sowie elastischen Fasern untersucht. Das Verteilungsmuster von Vimentin und Hyaluronsäure wurde ebenfalls analysiert.
Im semiquantitativen Teil der Arbeit wurden verschiedene EZM-Komponenten untersucht. Die Komponenten Vimentin, Hyaluronsäure, elastische Fasern, retikuläre Fasern, kollagene Fasern und die Anzahl der Blutgefäße wurden im Hinblick auf symmetrische Verteilung analysiert. Des Weiteren wurde die Länge der Stimmlippen und die Epitheldicke gemessen und verglichen. Hierbei lagen alle Werte im Konfidenzintervall. Lediglich ein Tier (Kalb 16) lag bei der immunhistochemischen Färbung gegen Elastin außerhalb dieses Bereichs.
Schlussfolgerungen
Die Verteilung der analysierten EZM-Komponenten ist größtenteils vergleichbar zu bereits beschriebenen Färbe-Mustern der Lamina propria anderer Spezies.
Innerhalb dieser Arbeit konnten keine Auffälligkeiten bzgl. der Symmetrie der Stimmlippen gefunden werden. Bei Kalb 16 handelt es sich am ehesten um einen Messfehler, da in anderen Färbungen dieses Tieres keine Auffälligkeiten auftraten. Weitere Untersuchungen an einer größeren Zahl an Individuen wären nötig um noch validere Aussagen machen zu können. Weitere Untersuchungen im Hinblick auf Narbenbildung und Veränderungen im Alter sollten an älteren Versuchstieren initiiert werden
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
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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