1,720,975 research outputs found

    Submental Orotracheal Intubation: An Alternative to Tracheotomy in Transfacial Cranial Base Surgery

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    This retrospective study evaluated the safety and efficacy of submental intubation not only for trauma treatment but also for oncological cranial base surgery. The medical records of 24 patients who underwent submental intubation from 1996 to 2002 were reviewed. There were 6 procedures for craniofacial trauma, 12 transmaxillary approaches to the clivus for clivus chordomas, and 6 transmaxillary approaches to the cranial base for chondrosarcomas. Time required for intubation, accidental extubation, postoperative complications, and the healing of intraoral and submental scars were evaluated. The submental orotracheal intubation was completed successfully in all patients. No accidental extubations or tube injuries occurred. The mean time required for intubation was 5 minutes. The only complication was one case of superficial infection of the submental wound. The intraoral and submental accesses healed with minimal scarring in all patients. Submental orotracheal intubation is a useful and safe technique for airway management of craniomaxillofacial traumas and during transfacial approaches to the cranial base. It avoids the complications associated with tracheostomy. It also permits considerable downward retraction of the maxilla after a Le Fort I osteotomy and is associated with good clival exposure. Furthermore, it does not interfere with maxillomandibular fixation at the end of the surger

    Current therapeutic options and novel molecular markers in skull base chordomas

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    Chordomas are extremely rare tumours. They arise in the spheno-occipital region in 35% of cases. Chordomas usually present benign histopathological features but often exhibit a malignant clinical behaviour. Radical surgical removal and high-dose radiation therapy seem to be effective in tumour control and to improve survival rate. Despite the advancements in microsurgical techniques and the development of radiation therapies, clival chordomas still represent a challenge. Nevertheless it appears that chordomas that have been resected to the same extent and that received post-operative radiotherapy might exhibit different rates of regrowth. This result supports the hypothesis that the recurrence rate of chordomas might be dependent on biological variables other than the extent of resection and the post-operative radiotherapy. Genetic and molecular studies on oncogenesis of chordomas are still limited, but they represent the basis for the development of molecular targeted therapies. We present a review of the current knowledge about skull base chordomas biology, therapeutic options and related clinical outcom

    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

    Quantification of clival and paraclival exposure in the Le Fort I transmaxillary transpterygoid approach : a microanatomical study

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    The authors describe a modified Le Fort I maxillotomy with medial and posterior antrectomy and removal of the pterygoid plates, aimed at improving the lateral surgical exposure during open transmaxillary surgery for pathological conditions involving the clivus. A cadaveric microanatomical study was conducted to compare the planimetric exposures allowed by the transmaxillary transpterygoid (TMTP) approach and the standard Le Fort I maxillotomy (STM). METHODS: Six cadaveric specimens that had been fixed with glutaraldehyde and injected with latex were dissected to obtain morphometric measurements after both TMTP and STM approaches. The anatomical areas exposed by the surgical approaches were calculated using ImageJ 1.37a software. RESULTS: As expected, the TMTP approach allowed for a greater surgical exposure, with an incremental area exposed ranging from 4.9 to 7.6 cm(2) (mean ± standard deviation 6.4 ± 1.2 cm(2), 95% CI 5.4-7.4 cm(2)). The amount of additional anatomical area visualized, as recorded as a percentage increase after the TMTP approach when compared with the STM approach, ranged from 83 to 109% (mean 99%). CONCLUSIONS: The lateral surgical exposure allowed by the STM approach is limited by the pterygoid plates. The TMTP approach significantly improves the exposure of the anatomical regions lateral to the clivus, allowing access to the pterygopalatine and medial infratemporal fossae. In comparison with the STM, the TMTP approach allows for a surgical exposure that is nearly double. The authors conclude that the TMTP approach provides a significant improvement in the surgical exposure of the lateral paraclival areas, when compared with the STM approac

    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

    Author Index

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    koamabayili/VECTRON-author-checklist: VECTRON author checklist

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    We 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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