1,720,958 research outputs found
Mouth diseases and dental materials: potential for study with cytofluorometry,Flogosi orali e materiali dentari: potenzialit{\`a} di studio tramite citofluorimetria
No full textBackground: The potential dental materials have of inducing mouth diseases is well known, and various methods have been developed to investigate this phenomenon. Among these there are histological studies of the pulp and periodontium exposed to dental materials, both in vivo and in vitro in humans and animals. Other studies are based on the clinical observation of the effects induced by dental materials. Aim of the paper is to evaluate the use of flow cytometry to analyse crevicular fluid to study its content in terms of inflammatory cells and inflammation mediators.
Methods: Samples of crevicular fluid were collected by aspiration using a bevelled needle mounted on a 5 ml syringe from patients without periodontitis and with periodontitis and multiple heterogeneous dental restorations. This method was adopted since it allows to place the cells of the fluid in suspension. Part of the fluid was analysed by cytology and part by flow cytometry.
Results: In the patients without periodontal disease cytological examination revealed the presence of desquamated epithelial cells and colonies of cocci, rods and spirochaetae. In the patients with periodontal disease the same examination revealed, besides the above, the presence of inflammatory cells. Flow cytometry confirmed the findings of cytological examination, thus proving to be an effective method for studying crevicular fluid.
Conclusions: This method allows to identify specific inflammatory cells or mediators of inflammation in crevicular fluid and may therefore prove to be very useful in the study of alterations induced by some dental materials at the level of the gingival sulcus
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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