1,720,980 research outputs found
Seven-Year Retrospective Study on Conometric Retention for Complete Fixed Prosthesis
Full text linkThe aim of the present work was to evaluate retrospectively, after seven years of function, the efficacy of a conometric retention to stabilize complete prostheses (CPs) on four implants. Data from twenty-three patients with CPs supported by four implants, with at least seven years of follow up were retrieved. All the CPs were immediately fixed to the implants using a conometric retention. Outcome measures were prosthesis and implant success, biological and prosthetic complications, probing pocket depth changes, marginal bleeding, and plaque index changes. A total of 92 implants were evaluated. No fixture or abutment fractures were reported. No abutment unscrewing was reported. Four framework fractures occurred after three, four, six, and seven years of function. The overall success rate of the rehabilitation was 82.6%. Mucositis was observed in eight patients and 13 implants. No peri-implantitis was recorded. A 0.55 mm difference of PPD and 0.74 mm of MBL was recorded after seven years (p < 0.001). The present implant-supported conometric retention system proved to be effective in giving fixed retention to a CP supported by four implants. Biological complications were easily detected and treated. An adequate metal framework should be provided to the definitive restoration to avoid fractures in the long term
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
Centriolar defects, centrin 1 alterations, and FISH studies in human spermatozoa of a male partner of a couple that produces aneuploid embryos in natural and artificial fertilization
Full text linkPurpose: To study the potential paternal contribution to aneuploidies in the man of a couple who obtained trisomic embryos with natural and assisted fertilization. Methods: Semen analysis, immunofluorescence for localization of tubulin and centrin 1, transmission electron microscopy (TEM), and fluorescence in situ hybridization (FISH) analysis for chromosomes 18 and 9 were performed. Sperm of fertile men were used as controls. Results: The percentages of sperm motility and normal forms were decreased. The percentages of sperm with tail reduced in dimension, headless tails, coiled tails, and altered head-tail junction were significantly higher (P < 0.01) in the patient than in controls, whereas the percentage of sperm with a normal centrin 1 localization (two spots in the centriolar area) was significantly reduced (P < 0.01) in the patient. Immunofluorescence with anti-tubulin antibody showed that in most of the patient’s sperm connecting pieces (83.00 ± 1.78%), two spots were present, indicating prominent proximal centriole/centriolar adjunct and evident distal centriole, whereas controls’ sperm displayed a single spot, indicating the proximal centriole. The percentage of sperm with two spots was significantly higher (P < 0.01) in the patient than in controls. TEM analysis showed that centriolar adjuncts of the patient’s sperm were significantly longer (721.80 ± 122.26 nm) than in controls’ sperm (310.00 ± 64.11 nm; P < 0.001). The aneuploidy frequencies of the patient’s sperm, detected by FISH analysis, were increased with respect to controls. Conclusion: A paternal contribution to sperm aneuploidies cannot be excluded since the patient’s sperm showed altered morphology, immature centriolar adjunct, presence of evident distal centriole, scarce presence of centrin 1, and high aneuploidy frequency
Accuracy of 3d digital modeling of dental arches
Full text linkObjective: The aim of the study was to verify and compare the accuracy of full-arch digital impressions obtained using two intraoral scanners and three scanning methodologies. Methods: A resin model created with dental 3-D printing was scanned by a reference scanner (Zfx Evolution-Zimmer Biomet, Palm Beach Gardens, FL) in order to obtain a 3D reference; the same resin model was then scanned with two different intraoral scanners (Zfx IntraScan and Carestream 3600-CS 3600®, Carestream, Rochester, NY, USA) using: Technique A (from tooth #27 up to tooth #17); Technique B (from tooth #11 up to tooth #17 and then from tooth #21 up to tooth #27) and Technique C (from tooth #22 up to tooth #17, and then from tooth #12 up to tooth #27 — the MeshLab software v. 1.3.3 was then used to match the two scans). The scans obtained were superimposed over the reference scan by means of a software, and the volumetric discrepancies were calculated. Results: The mean results for the Zfx Intrascan scanner were: Technique A = 302.47 ± 37.42 μm; Technique B = 180.45 ± 29.86 μm; Technique C = 147.34 ± 28.23 μm. The mean results for the Carestream 3600 scanner were: Technique A = 303.59 ± 40.20 μm; Technique B = 181.53 ± 29.61 μm; Technique C = 142.28 ± 35.33 μm. Technique C, used by both scanners, produced less volumetric discrepancies compared to the other techniques. Conclusions: The scanning technique had a statistically significant effect on the quality of the scan (p < 0.0001), whereas the scanner did not present any significant influence (p = 0.91)
Medication-related osteonecrosis of the jaw and dental implants failures: a systematic review
No full textCentriolar defects, centrin 1 alterations and FISH studies in hu- man spermatozoa of a man of a couple that produces aneuploid embryos in natural and artificial fertilization
No full textBacterial adhesion to grade 4 and grade 5 turned and mildly acid-etched titanium implant surfaces: An in vitro and ex vivo study
Full text linkThe aim of the present study was to investigate the bacterial adhesion to titanium (Ti) implant surfaces, different for composition and topographic features. Grade 4 and 5 turned (T-4, T-5,) and mildly acid-etched (MA-4, MA-5) Ti 6 × 1 mm disks were topographically analyzed by scanning electronic microscopy and 3D profilometry. Bacterial cultures (Streptococcus sanguinis) were in vitro seeded and, after two and six hours, adherent bacteria were quantified by colony-forming unit (CFU) counting. Ti samples were also exposed to the oral environment of six periodontally healthy volunteers and, after 12 h, the formed biofilm was evaluated by CFU counting. Inter-group differences were tested by the Mann–Whitney U-Test (α = 0.05). MA surfaces were significantly rougher than T ones, whereas no difference between grade 4 and grade 5 disks was detected. Significantly higher in vitro bacterial adhesion for MA than T disks was shown at two and six hours. Significantly higher values of CFU counting for MA than T surfaces and for grade 5 than grade 4 disks were found at the 12 h-ex vivo test. Bacterial adhesion showed to be sensitive to both Ti surface topography and composition, with possible implications on peri-implant tissue health maintenance
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