1,720,966 research outputs found
SEM analysis of the interference between bleaching and enamel etching
No full textAim. SEM (Scanning Electron Microscope) evaluation of the existance of micromorphological differences between unbleached enamel (SNS) and bleached enamel (SS) and between etched enamel (SM) and etched after bleaching enamel (SSM). In the latter cases the etching agent has been applied right after bleaching to explore potential interferences between the two processes.
Methods. 12 upper incisors have been selected. The professional bleaching agent Opalescence Quick 45% PF (Ultradent Products Inc.) has been applied for 30 minutes on part of the vestibular surface of each specimen. After rinsing the specimens, a 37% ortophosphoric acid (Best Etch – Vista Dental Products) has been applied for 45 seconds on the whole surface, including the enamel part that had been bleached. The effect on the enamel surface has been evaluated with the scanning electron microscope (SEM).
Results. and Conclutions. We obtained 48 pictures that showed micromorphological differences between SNS and SS. In most of the cases (9 specimens on 12 examined) there are no micromorphological differences between SM and SSM; but since on the other 25% of the cases, the difference between SM and SSM is rimarkable, we can hypothesize that is the natural composition of the idrossiapathite of each element that determines the final answer to the consecutive use of peroxide and ortophosphoric acid
Histopathological and therapeutical aspects of cervical lesions
No full textThe term "cervical lesions" definies all the alterations consisting in a loss of hard dental tissues located along the cement-enamel junction, and may be more specifically defined as carious lesions (LCC) and non-carious lesions (NCCL). The non-carious cervical lesions are characterized by the loss of mineralised dental tissue in the absence of a carious process. This definition includes three different lesion categories: abrasion, erosion and the cervical lesions caused by stress (abfractions). In this paper the authors explain the histological, clinical, preventive findings of NCCL and try to give some guidelines to choose the appropriate material to restore different types of non carious cervical lesions
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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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