1,720,969 research outputs found

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The 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

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    “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

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    We 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

    Bone augmentation at implant dehiscences and fenestrations. A systematic review of randomised controlled trials

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    Purpose: To evaluate the efficacy of the bone augmentation procedure at dehiscence or fenestration defects in one-stage implant insertion and to evaluate which is the most effective procedure. Materials and methods: A systematic review of articles selected from MEDLINE, Cochrane Central Register of Controlled Trials (CENTRAL) and Google Scholar was performed. Additional studies handsearched and found in printed versions of the principal dental implant journals were included. Only randomised controlled trials (RCTs) were included. Outcome variables considered were implant failure, complications, aesthetic and functional satisfaction, complete fill of the defect, clinical and radiological bone level variation, and vestibular peri-implant recession. Independent data extraction by two authors using predefined data fields, including study quality indicators, was completed. All pooled analyses were based on random effects models. Results: A total of 65 full-text articles were examined in detail. Forty-six of the 65 articles did not meet the inclusion criteria. Nineteen articles involving 15 trials were identified for inclusion in the review. Only one study was considered to be at a low risk of bias. The included studies involved 396 patients and 535 implants. Comparing the test group using membranes with the control without membranes, a statistically significant difference was obtained for vertical variation of the peri-implant defect; the difference was 1.64 mm (three RCTs, 95% CI from 0.47 to 2.80 mm; P = 0.006, I2= 0%) favouring the use of a membrane. Non-resorbable polytetrafluoroethylene (ePTFE) membranes obtained a complete clinical fill of defects more frequently than resorbable polylactide/polyglycolide (PLGA) membranes. The odds ratio was 0.15 (two RCTs, 95% CI from 0.04 to 0.64 mm; P = 0.01, I2= 0%), favouring the use of ePTFE membranes. No differences were observed comparing nonresorbable ePTFE membranes and resorbable collagen membranes. The comparison between crosslinked membranes and collagen native membranes yielded a very high heterogeneity for vertical variation of the peri-implant defect (two RCTs, I2= 91%, P = 0.001). Dehiscence complications were more frequent using cross-linked membranes but the odds ratio was not significant (three RCTs, odds ratio 0.44, 95% CI from 0.18 to 1.10; P = 0.08, I2= 4%). Conclusions: Overall, the evidence is not sufficiently robust to determine if any treatment is needed and which is the best treatment for dehiscence or fenestration defects at one-stage implant placement. Only 15 trials were included and the majority are of limited sample size, have short follow-ups as well as having a high risk of bias. The use of a membrane can contribute to the regeneration of the hard tissue in horizontal one-stage augmentation. The complete fill of the defect was obtained more frequently when a non-resorbable ePTFE membrane was used compared to a resorbable PLGA membrane. No differences were observed comparing non-resorbable ePTFE membranes and resorbable collagen membranes. No substantial differences were obtained using different non-resorbable membranes and grafts, and the results were positive for the variables examined. A high result of heterogeneity was observed in studies dealing with cross-linked membranes.Purpose: To evaluate the efficacy of the bone augmentation procedure at dehiscence or fenestration defects in one-stage implant insertion and to evaluate which is the most effective procedure. Materials and methods: A systematic review of articles selected from MEDLINE, Cochrane Central Register of Controlled Trials (CENTRAL) and Google Scholar was performed. Additional studies handsearched and found in printed versions of the principal dental implant journals were included. Only randomised controlled trials (RCTs) were included. Outcome variables considered were implant failure, complications, aesthetic and functional satisfaction, complete fill of the defect, clinical and radiological bone level variation, and vestibular peri-implant recession. Independent data extraction by two authors using predefined data fields, including study quality indicators, was completed. All pooled analyses were based on random effects models. Results: A total of 65 full-text articles were examined in detail. Forty-six of the 65 articles did not meet the inclusion criteria. Nineteen articles involving 15 trials were identified for inclusion in the review. Only one study was considered to be at a low risk of bias. The included studies involved 396 patients and 535 implants. Comparing the test group using membranes with the control without membranes, a statistically significant difference was obtained for vertical variation of the peri-implant defect; the difference was 1.64 mm (three RCTs, 95% CI from 0.47 to 2.80 mm; P = 0.006, I2= 0%) favouring the use of a membrane. Non-resorbable polytetrafluoroethylene (ePTFE) membranes obtained a complete clinical fill of defects more frequently than resorbable polylactide/polyglycolide (PLGA) membranes. The odds ratio was 0.15 (two RCTs, 95% CI from 0.04 to 0.64 mm; P = 0.01, I2= 0%), favouring the use of ePTFE membranes. No differences were observed comparing nonresorbable ePTFE membranes and resorbable collagen membranes. The comparison between crosslinked membranes and collagen native membranes yielded a very high heterogeneity for vertical variation of the peri-implant defect (two RCTs, I2= 91%, P = 0.001). Dehiscence complications were more frequent using cross-linked membranes but the odds ratio was not significant (three RCTs, odds ratio 0.44, 95% CI from 0.18 to 1.10; P = 0.08, I2= 4%). Conclusions: Overall, the evidence is not sufficiently robust to determine if any treatment is needed and which is the best treatment for dehiscence or fenestration defects at one-stage implant placement. Only 15 trials were included and the majority are of limited sample size, have short follow-ups as well as having a high risk of bias. The use of a membrane can contribute to the regeneration of the hard tissue in horizontal one-stage augmentation. The complete fill of the defect was obtained more frequently when a non-resorbable ePTFE membrane was used compared to a resorbable PLGA membrane. No differences were observed comparing non-resorbable ePTFE membranes and resorbable collagen membranes. No substantial differences were obtained using different non-resorbable membranes and grafts, and the results were positive for the variables examined. A high result of heterogeneity was observed in studies dealing with cross-linked membranes

    Masticatory Function in Stage IV Periodontitis Patients Treated with Fixed Prosthetic Rehabilitations: A Case Series

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    The present study assessed the impact of a fixed prosthetic rehabilitation on masticatory function in patients diagnosed with stage IV periodontitis. Eligible participants were adults in need of complex rehabilitation due to masticatory dysfunction. Masticatory function was evaluated using the two-colored chewing gum mixing ability test (VOH) at the diagnostic phase (T0), 1 week after delivery of the prosthetic prototype (T1), and 1 week after delivery of the final prosthetic solution (T2). Ten subjects were treated with a fixed prosthesis following periodontal and implant surgery using an individualized, fully digital workflow. Full-mouth plaque and bleeding scores, pocket depth, and clinical attachment level improved significantly. VOH was 0.472 ± 0.168 at T0, 0.358 ± 0.166 at T1, and 0.250 ± 0.123 at T2. A significant improvement in VOH was observed from T0 to T1 (difference: –0.114; 95% CI: –0.199 to –0.029; P = .014) and from T1 to T2 (difference: –0.108; 95% CI: –0.200 to –0.015; P = .027). From T0 to T2, VOH increased by 44.3%. Self-perceived assessment of masticatory function also improved from T0 to T2 (P = .002). The fixed prosthetic rehabilitation in patients with stage IV periodontitis allowed for a significant improvement in objective and subjective measurements of masticatory function. Int J Periodontics Restorative Dent 2024;44:103–113

    Dispelling the Myths Behind First-author Citation Counts

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    We 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

    The Multilayer GBR Technique: An Alternative Approach for One-Stage Transmucosal Implant Placement in the Presence of Horizontal Defects. A Case Series

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    This study presents a one-stage technique for horizontal guided bone regeneration and transmucosal implant placement in the presence of hard and soft tissue defects. The proposed technique uses autologous bone particles, deproteinized bovine bone matrix, collagen membranes, and concentrated growth factor membranes to create a multilayer barrier and enhance tissue regeneration. Four patients were treated with a total of seven implants. Digital analyses of intraoral scan data taken at baseline and at 6 months postsurgery showed a mean increase in tissue volume of 157.4 mm(3). The patient satisfaction was high, and no complications were observed

    Author Index

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