1,720,956 research outputs found
Extensive Dental Caries in Patients with Oral Chronic Graft-versus-Host Disease
No full textThe oral cavity is one of the sites most frequently affected by chronic graft-versus-host disease (cGVHD) after allogeneic hematopoietic cell transplantation (alloHCT) and can be a significant source of patient morbidity due to both mucosal and salivary gland involvement. The development of dental decay is a potentially devastating oral complication that has only rarely been reported in the transplantation literature. The purpose of this study was to comprehensively characterize a cohort of patients with cGVHD who subsequently developed extensive dental caries. A retrospective case-record review was conducted for patients who had undergone alloHCT at Dana-Farber/Brigham and Women's Cancer Center between 1990 and 2010 and developed cGVHD-associated rampant dental decay. All patients underwent dental evaluation, involving soft and hard tissue examination and dental radiography, before and after alloHCT. Any dental caries diagnosed at the pre-alloHCT evaluation were treated definitively, such that all patients were considered free of caries at the time of admission for alloHCT. A total of 21 patients were identified, with a median time of cGVHD onset of 5.4 months (range, 2.2-18.5 months) after alloHCT. All patients were diagnosed with oral cGVHD, with 90% demonstrating mucosal involvement and 95% demonstrating salivary gland involvement. Post-alloHCT dental evaluation was performed at a median of 22 months (range, 4-81) after alloHCT, when 10 patients were diagnosed with gross caries and 8 patients had 4 or more affected teeth. Cervical and interproximal patterns of dental caries were frequently diagnosed. The proportions of patients with gross caries, one surface caries, and more than one surface caries (classified as 0, 1-3, and ≥4, respectively) were significantly higher after alloHCT than before alloHCT, with at least 50% of patients experiencing an increase. Patients with oral cGVHD who were free of caries at the time of transplantation developed extensive areas of cervical decay at a median of less than 2 years after alloHCT. This is the first comprehensive characterization of this severe late complication of alloHCT and oral cGVHD. Greater awareness by transplantation oncologists and dentists, as well as more aggressive preventive measures, are needed, as are further prospective studies to better elucidate the incidence of this complication, identify risk factors, and evaluate the effectiveness of preventive interventions
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
Development of an advanced numerical model of heat transfer in a bone-implant system
No full textOBJECTIVES: Implant removal can be required in case of malpositions, biological or mechanical failures. This procedure, performed with trephine burs, piezosurgery or counter-torque ratchets, often results in bone defects requiring corrections with advanced regenerative techniques. Few case reports describe implant removal after weakening the bone-implant interface by applying a localized heating to the fixture: however, this procedure must be standardized to obtain a predictable result, avoiding extensive bone damage. Aim of this preliminary study is to create a high-fidelity numerical model of the bone-implant system, to be validated by in vitro and in vivo tests, for predicting the most appropriate parameters necessary for a minimally invasive implant removal using heating.
MATERIAL AND METHODS: A 3-D virtual advanced numerical model was created using ANSYS CFX, in order to simulate the behavior of a bone-implant system under thermal variations. Various parameters can be adjusted to set the model: heating modalities (temperature and/or heat flux, time and source) and system characteristics (implant geometry and material, type of bone). In vitro tests were performed using titanium implants (Premium, Sweden & Martina, Italy - 3.85 x 8.5, 10 and 13 mm). Implants were inserted in bovine bone (stabilized at 37 ± 0.5 °C), and then heated using an endodontic heat carrier (System B, Sybron Endo, USA). Bone temperatures were recorded using thermocouples at different depths (1 mm, middle and apex of implant) and at different distances from the implant [0.5 mm (T1), 1 mm (T2), 1.5 mm (T3) and 2 mm (T4)]. Non parametric data were analyzed using Friedman and Wilcoxon tests.
RESULTS: The heat carrier, set at 100 °C, was placed in contact with the inner part of the implants for 140 sec. The threshold temperature of 47 °C was reached in T1 after 65.2 ± 11.7 sec, in T2 after 89.3 ± 29.1 sec, in T3 after 110.9 ± 29.6 sec, in T4 the temperature of 47 °C was never reached within 140 sec. Differences between T1, T2, T3 and T4 resulted statistically significant (p<0.05). Implant length and distance from heat source are factors influencing temperature variations.
CONCLUSIONS: From the results of this preliminary study, it seems possible to produce a controlled thermally-induced injury to the bone-implant interface, allowing for a minimally invasive implant removal. Various parameters (implant geometry and material, bone characteristics) must be considered to set temperature and heating duration. In vivo histologic studies are necessary to analyze quality and quantity of bone-implant interface modifications after heat-induced injury, before starting any clinical application
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
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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