1,721,041 research outputs found
Sinus augmentation using BMP-2 in a bovine hydroxyapatite collagen carrier in dogs
Full text link치과대학/박사Objective
The objective of this study was to determine the efficacy of bone morphogenetic protein 2 (BMP-2) in a bovine hydroxyapatite/collagen (BHC) carrier to augment bone formation in a canine nasal sinus model.
Material and Methods
Eight mongrel dogs, approximately 12 months old and 30 kg in weight were used. Following preparation of bilateral sinus access windows, BHC alone (control) or loaded with E.coli-derived BMP-2 at 0.1 mg/mL was implanted in 4 animals, and BHC loaded with E.coli-derived BMP-2 at 0.5 and 1.5 mg/mL was implanted in 4 animals. The animals were euthanized at 20 weeks when block sections were obtained for micro-computed tomography and histometric analyses.
Results
Total augmented volumes did not differ significantly between groups. Histometric analysis showed significantly enhanced bone formation for the BMP-2 groups compared with control.
Conclusion
BMP-2 in a BHC carrier, even at the low 0.1-mg/mL concentration, induces osteogenic activity, enhancing local bone formation in a canine sinus model.ope
Maxillary sinus augmentation with biphasic calcium phosphate : a clinical and radiographic study
Full text linkDept. of Dentistry/석사The aim of this study was to evaluate 3.5 years-cumulative survival rate of implants placed on augmented sinus using Osteon®, a bone graft material, and to assess the height of the grafted material through radiographic evaluation. Twenty patients were treated with maxillary sinus augmentation and 45 implant fixtures were installed simultaneously or after 6 months healing period. The height of the augmented sinus and the loss of marginal bone were measured by panoramic and intraoral radiographs immediately after augmentation and up to 42 months (mean 19.4) subsequently. Changes in the height of the sinus graft material were calculated radiographically. The cumulative survival rate was 95.56% in all 45 implants. Additionally, normal healing process without any complication was observed in all patients. The original sinus height was mean 4.3 mm and the augmented sinus height was mean 13.4 mm after the surgery. The mean marginal bone loss till 42 months was 0.52±0.56mm. The reduced height of Osteon® was 0.83±0.38 mm and it did not show significant correlation with the follow up periods (P=0.102). There were no statistically significant differences in reduced height of Osteon® according to the simultaneous/delayed implantation (P=0.299) and particle size of Osteon® (P=0.644). It can be suggested that Osteon® may have predictable result when it was used as a grafting material for sinus floor augmentation.ope
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
Strategies for implant surface decontamination in peri-implantitis therapy.
No full textPeri-implantitis is an infectious disease that leads to progressive bone loss. Surgical therapy has been advocated as a way of halting its progression and re-establishing peri-implant health. One of the most challenging but crucial tasks in the management of peri-implantitis is biofilm removal to achieve reosseointegration and promote the reduction of peri-implant pockets. A wide variety of strategies have been used for implant surface decontamination. Mechanical means have been demonstrated to be effective in eliminating calculus deposits and residual debris; however, the presence of undercuts and the grooves and porosities along the roughened implant surface make it difficult to achieve an aseptic surface. In conjunction with mechanical measures, use of chemical adjuncts has been advocated to dilute bacterial concentrations, destroy the bacteria's organic components and eliminate endotoxins. Pharmacological adjuncts have also been recommended to diminish the bacterial load. Other strategies, such as use of lasers, implantoplasty and electrolysis, have been suggested for implant surface decontamination to promote predictable clinical and radiographic outcomes
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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