1,720,973 research outputs found
Amorphous carbon coatings for extending the service life of total knee replacements
No full text10.25593/open-fau-929Die Haltbarkeit einer Knie-Totalendoprothese – gerade bei jüngeren, aktiven Patient:innen – bei erhöhter Beanspruchung ist unzureichend. Demnach führen implantatassoziierte Verschleißpartikel zu einer asepti-schen Endoprothesenlockerung infolge von Osteolyse und somit zu vorzeitigem Endoprothesenversagen. Dabei können amorphe Kohlenstoffschichten die hohen Anforderungen an Implantate erfüllen. Sie vereinen ein tribologisch wirksames mit einem biokompatiblen Verhalten und hervorragenden mechanischen Eigenschaften. Der Fokus dieser Arbeit lag hierbei auf der Applikation sowie auf der mechanisch-biotribologischen präklinischen in vitro Untersuchung von amorphen Kohlenstoffschichten auf metallisch/polymeren Artikulationspartnern von Endoprothesen. Mithilfe rheologischer Untersuchungen und numerischer Simulationen wurde eine anwendungsbezogene, biotribologische Prüfkette, bestehend aus einem Kugel-Drei-Stifte-Tribometer, Stift-Scheibe-Tribometer und vollkinematischen Kniesimulator, aufgespannt. Diese Prüfkette erlaubte eine umfangreiche Verschleißanalyse vieler Kontaktkombinationen in vertretbarer Zeit bezüglich dominierender Verschleißmechanismen, typischer Partikelgrößen und -morphologien sowie deren Korrelation über die Prüfglieder hinweg. In allen Prüfgliedern zeigte sich die biotribologische Wirksamkeit der amorphen Kohlenstoffschichten, welche eine deutliche Erhöhung der Standzeit von Endoprothesen ermöglichen.The durability of a total knee endoprosthesis – especially in younger, active patients, is due to increased higher stresses insufficient. Accordingly, implant-associated wear particles lead to aseptic endoprosthesis loosening as a result of osteolysis and thus to premature failure of the endoprosthesis. Amorphous carbon coatings can meet the high requirements for implants. They combine tribologically effective behavior with high biocompatibility and excellent mechanical properties. The focus of this work was on the application and the mechanical-biotribological preclinical in vitro investigation of amorphous carbon coatings on metallic/polymeric articulation partners of endoprostheses. Using rheological investigations and numerical simulations, an application-related, biotribological test chain consisting of a ball-on-three-pin tribometer, pin-on-disk tribometer and fully kinematic knee simulator was established. This test chain allowed a comprehensive wear analysis of numerous contact combinations in a reasonable time with respect to dominant wear mechanisms, typical particle sizes and morphologies, as well as their correlation across the test links. In all test links, the biotribological effectiveness of the amorphous carbon coatings was shown, indicating a significant increase in the service life of endoprostheses
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
Diamond-like Carbon coatings for artificial implants
No full textThis chapter delves into the enhancement of implant performance through diamond-like carbon (DLC) coatings, recognized for their exceptional mechanical, chemical, and biocompatible properties, making them ideal for various biomedical applications. The chapter focuses on orthopedic applications, where DLC coatings improve wear resistance and longevity of implants, and promote osteointegration by enhancing cell adhesion and proliferation. In dental implants, DLC coatings boost biocompatibility and reduce infection risk, while also enhancing the durability of orthodontic brackets. This chapter details the requirements for DLC coatings in artificial implants and reviews their use in load bearing and dental implants, respectively. The chapter concludes with a summary of findings and identifies future research challenges, emphasizing the need for translating model-level advancements to component-level applications and addressing the reproducibility issues in dental applications. Overall, DLC coatings show significant potential to improve patient outcomes, reduce revision surgeries, and enhance comfort in both orthopedic and dental medicine
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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