1,721,012 research outputs found
Identifizierung epigenetischer Alterationen als Biomarker für Genese, Progression und Therapieansprechen des Nierenzellkarzinoms
Full text linkDifferential expression of urocortin in human testicular germ cells in course of spermatogenesis: role for urocortin in male fertility ?
No full textTo provide the first insights into the potential role of urocortin in mammalian spermatogenesis, we studied the expression of urocortin and corticotropin-releasing factor receptors 1 and 2 in the human testis. Urocortin is a bioactive peptide with antiapoptotic and antiproliferative properties. The proper regulation of apoptosis and proliferation is of high physiologic relevance in the control of spermatogenesis in adulthood and of the noncycling stage of gonocytes in fetal life
Differenzierte Betrachtung der Lernkurven eines erfahrenen offen-Operateurs bei Einführung des Roboting am Beispiel der radikalen Prostatektomie
Full text linkDurch Bewertung des Outcomes und Erkennen von Fehlentwicklungen kann die Qualität neuer OP-Verfahren verbessert werden. Es sollen die steigende Erfahrung des Operateurs der ersten 250 RALPs (2011-2013) mit steigender Anzahl durchgeführter Operationen durch differenzierte Lernkurven dargestellt sowie direkte und indirekte Einflussfaktoren identifiziert werden. Die Auswertung umfasst u.a. Operationszeit, Komplikationsrate, Anzahl der Nerverhalte sowie funktionelles und onkologisches Outcome. Es wurden 5 Zeitgruppen zu je 50 Patienten gebildet und ihre Homogenität bezüglich präoperativer Parameter (cT, GS, PSA, BMI, Komorbiditäten, präoperative Gesundheit, Lebensqualität, Potenz und Kontinenz) festgestellt. Aus der Analyse von OP-Zeiten, Komplikationen, onkologischem Outcome, Kontinenz, Potenz und Hospitationsdauer wurden Lernkurven erstellt. Mit steigender Erfahrung nahm die Rate der Nerverhalte bei fallender Prostatapräparationszeit und konstanter Gesamtkomplikationsrate zu. Potenzrate nach 12 Monaten, Leckagerate, Katheterverweildauer und Hospitalisationsdauer waren konstant, Lebensqualität, Gesundheit und Kontinenz nach 12 Monaten wurden besser eingeschätzt. Alle OP-Zeiten fielen bis zu Zeitgruppe 3 ab, ein Anstieg ab Gruppe 4 erklärt sich durch Einarbeitung weiterer Assistenten und Oberärzte. Die max. R1-Rate (32%) in Zeitgruppe 3 war auf ein signifikant häufigeres Auftreten von lokal fortgeschrittenen Tumoren zurückzuführen. Durch die Lernkurven wurde eine Verbesserung der prozeduralen Qualität bei stabilem onkologischem Outcome und niedriger Komplikationsrate nachgewiesen. Die Assistenz durch unerfahrene Kollegen führte ohne Beeinflussung von Outcome oder Komplikationsrate zu einer längeren OP-Zeit. Die Lernkurve des Hauptoperateurs zeigte eine Verbesserung der OP-Zeit und Zunahme vollständiger Nerverhalte. Kontinenz, Gesundheitszustand und Lebensqualität wurden 12 Monate postoperativ besser bewertet
Urocortin and corticotropin-releasing factor receptor 2 in human renal cell carcinoma : disruption of an endogenous inhibitor of angiogenesis and proliferation
Full text linkUrocortin (Ucn) exerts its actions through activation of two corticotropin-releasing factor receptors (CRFRs), CRFR1 and CRFR2. Involvement of Ucn/CRFR2 system in pathophysiological conditions such as the regulation of angiogenesis and inhibition of proliferation has been already reported. Suppression of neovascularization through reduction of vascular endothelial growth factor and inhibition of tumor cell cycling is modulated mainly through activation of CRFR2. To find out a possible involvement of Ucn/CRFR2 in kidney tumor, we examined the expression of Ucn and CRFR2 in normal and tumoral kidney specimens
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
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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