1,720,961 research outputs found

    COLOR MATCH EVALUATION OF TWO SINGLE SHADE COMPOSITES BEFORE AND AFTER BLEACHING PROCEDURE

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    Aim: the aim of this case report was to evaluate instrumental and visual color match of two single shade resin-based com- posites in human extracted teeth before and after bleaching treatments. Methods: two extracted human posterior sound teeth were used. Round shaped V class cavities (2x2x4mm) were prepa- red buccally 2mm away from the CEJ. Two single shade resin composites (ES-Essentia Universal, GC and CL-Clearfill Maje- sty ES2 Universal, Kuraray) were used for the restorations. To- oth color was measured 1mm beside the cavity and in the cen- ter of the restoration using a spectrophotometer (VITA Easysha- de V, VITA Zahnfabrik). Visual analysis were carried out by 16 calibrated observers and differences were graded as 0:excel- lent match; 1:very good match; 2:not so good match; 3:obvious mismatch; 4:huge mismatch. Teeth were then bleached using 40% H2O2 (Opalescence Boost PF, Ultradent) and instrumental and visual evaluations were replied after 24 hours. Results: at baseline, both ES restoration and tooth showed an A3 VITA scale grade, and respectively A2 and C2 after blea- ching. Color match visual analysis showed a mean value of 0.25 both prior and after bleaching. At baseline, both CL resto- ration and tooth showed an A4VITA scale grade, and respecti- vely A3 and C3 after bleaching. Color match visual analysis showed a mean value of 0.87 before and 0.31 after bleaching. Conclusions: within the limits of a single case report, both composites seem to have excellent color match properties with the surrounding tooth structure, from both instrumental and visual points of view

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The 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

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    “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

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    We 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

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    We 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

    Author Index

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    koamabayili/VECTRON-author-checklist: VECTRON author checklist

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    We 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

    Assessment of colour modifications in two different composite resins induced by the influence of chlorhexidine mouthwashes and gels, with and without anti-staining properties: An in vitro study

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    Objectives: Chlorhexidine (CHX)-based products are the most effective chemical agents used in plaque control and oral disinfection. One of their side effects is tooth and restoration staining. For this reason, CHX products with anti-discolouration systems (ADS) have been developed. The aim of this in vitro study was to compare different CHX-based products (gel and mouthwash) with or without ADS in composite colour modification.Methods: Two hundred specimens were created, 100 of which were made of packable composite and 100 of flowable composite. After 24 h, colour coordinates (L*, a*, b*, C*, h degrees) were recorded using a spectrophotometer (T0). Then, all samples were subjected to a CHX/tea staining model and immersed in human saliva for 2 min. Composite specimens were divided in 10 groups (N = 20). Control groups (PC, FC) were soaked in distilled water and test groups (PG, PGads, FG, FGads, PM, PMads, FM and FMads) were immersed in CHX-based solutions or brushed with CHX gel. Then the cycle was repeated 6 times, and colour differences (Delta E-ab and Delta E-00) were finally calculated.Results: Through flowable composites, FC and FG showed the highest colour differences, respectively Delta E-ab = 3.48 +/- 1.0, Delta E-00 = 2.24 +/- 0.6 and Delta E-ab = 2.95 +/- 1.3, Delta E-00 = 1.53 +/- 0.6. In the composite groups instead, PM and PMads showed the highest colour differences, respectively Delta Eab = 2.78 +/- 1.3,Delta E00 = 1.94 +/- 0.8 and Delta E-ab = 2.71 +/- 1.4, Delta E-00 = 1.84 +/- 0.9.Conclusions: CHX-containing products are able to cause stains on restorative composite materials. Discolouration is more likely to occur in flowable composites than packable composites, and ADS-containing products cause fewer pigmentations than CHX products without ADS. Packable composites showed more staining after mouthwash treatment, whereas flowable composites underwent higher discolouration after treatment with gels
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