1,721,468 research outputs found
Horizontal mucosal thickness at implant sites as it correlates with the integrity and thickness of the buccal bone plate
No full textObjectivesTo histologically assess the association between the horizontal mucosal thickness (MT) at implant sites with the integrity and thickness of the buccal bone plate in a canine model. Materials and methodsTwo-piece titanium implants were placed at chronic-type lateral ridge defects. The resulting vestibular dehiscence-type defects (vertical dimensions of 2-8mm) were left untreated. After a submerged healing period of 2 and 8weeks (n=6 fox hounds each), dissected blocks were processed for histomorphometrical analyses [e.g. MT, bone thickness (BT) and residual defect length]. ResultsLinear regression revealed significant associations between vestibular MT and BT values after 2 (R-2=0.22, B=-0.37, P<0.0001) and 8weeks (R-2=0.37, B=-0.45, P<0.001) of healing. ConclusionThe present analysis has pointed to an inverse relationship between horizontal MT and BT values at the vestibular aspect of submerged titanium implants. MT was most pronounced in the absence of a buccal bone plate.ITI Foundation, Basel, Switzerland [528-2007
Automated 3D-2D registration of X-ray microcomputed tomography with histological sections for dental implants in bone using chamfer matching and simulated annealing
No full textWe propose a novel 3D-2D registration approach for micro-computed tomography (mu CT) and histology (HI), constructed for dental implant biopsies, that finds the position and normal vector of the oblique slice from mu CT that corresponds to HI. During image pre-processing, the implants and the bone tissue are segmented using a combination of thresholding, morphological filters and component labeling. After this, chamfer matching is employed to register the implant edges and fine registration of the bone tissues is achieved using simulated annealing. The method was tested on n = 10 biopsies, obtained at 20 weeks after non-submerged healing in the canine mandible. The specimens were scanned with mu CT 100 and processed for hard tissue sectioning. After registration, we assessed the agreement of bone to implant contact (BIC) using automated and manual measurements. Statistical analysis was conducted to test the agreement of the BIC measurements in the registered samples. Registration was successful for all specimens and agreement of the respective binary images was high (median: 0.90, 1.-3. Qu.: 0.89-0.91). Direct comparison of BIC yielded that automated (median 0.82, 1.-3. Qu.: 0.75-0.85) and manual (median 0.61, 1.-3. Qu.: 0.52-0.67) measures from mu CT were significant positively correlated with HI (median 0.65, 1.-3. Qu.: 0.59-0.72) between mu CT and HI groups (manual: R-2 = 0.87, automated: R-2 = 0.75, p < 0.001). The results show that this method yields promising results and that mu CT may become a valid alternative to assess osseointegration in three dimensions. (C) 2015 Elsevier Ltd. All rights reserved.Camlog Foundation, Basel, Switzerlan
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
The impact of dis‐/reconnection of laser microgrooved and machined implant abutments on soft‐ and hard‐tissue healing
No full textObjectives To (i) investigate the influence of different extensions of a laser microgrooved abutment zone on connective tissue attachment and (ii) assess the impact of a repeated abutment dis-/reconnection on soft- and hard-tissue healing. Materials and Methods Titanium implants were inserted epicrestally in the lower jaws of six dogs. Healing abutments with either partially (LP) or completely (LC) laser microgrooved margins or machined surface margins (M) were randomly allocated either to a single (1x)/repeated (2x) dis-/reconnection at 4 and 6weeks (test), respectively, or left undisturbed (control). At 6 and 8weeks, histomorphometrical (e.g. most coronal level of bone in contact with the implant [CBI], subepithelial connective tissue attachment [STC]) and immunohistochemical (Collagen Type-I [CI]) parameters were assessed. Results At control sites, LP/LC groups revealed lower mean CBL (8weeks, 0.95 +/- 0.51 vs. 0.54 +/- 0.63 vs. 1.66 +/- 1.26mm), higher mean STC (8weeks, 82.58 +/- 24.32% vs. 96.37 +/- 5.12% vs. 54.17 +/- 8.09%), but comparable CI antigen reactivity. A repeated abutment manipulation was associated with increased mean CBL (8weeks, 1.53 +/- 1.09 vs. 0.94 +/- 0.17 vs. 1.06 +/- 0.34mm), decreased STC (8weeks, 57.34 +/- 43.06% vs. 13.26 +/- 19.04% vs. 37.76 +/- 37.08%) and CI values. Conclusions It was concluded that (i) LC>LP abutments enhanced subepithelial connective tissue attachment and preserved crestal bone levels, (ii) repeated abutment dis-/reconnection during the initial healing phase (46weeks) may be associated with increased soft- and hard-tissue changes and (iii) LP and LC should be considered using a one abutment, one time approach.BioHorizons, Birmingham AL, US
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
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