1,720,988 research outputs found

    Infant mandibular distraction in absence of ascending ramus: case series

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    Background: Severe microretrognathia with the absence of ascending mandibular ramus is a challenging deformity and treatment must aim to avoid tracheostomy or remove it as soon as possible. Although it is not often reported, mandibular distraction osteogenesis represents a valid treatment option in infants affected by hypoplastic mandible Pruzansky-Kaban type IIb and III. Case presentation: The authors describe 3 cases of infants affected by severe respiratory insufficiency due to congenital mandibular hypoplasia, with follow up ranging from 4 to 8 years. Clinical and technical considerations on treatment choices and outcomes are discussed starting from review of the literature and direct clinical experience. Conclusion: Early mandibular distraction, specifically bidirectional distraction, is an effective and repeatable technique that leads to mandible lengthening with counterclockwise rotation, pogonion projection increase, anteropositioning of the tongue base, and expansion of oropharyngeal volume with positive effect on the respiratory problems of the infant. Even in Treacher Collins patients, known to have a low decannulation rate, all of these elements are essential for effective speech and swallowing therapy and for a subsequent attempt of decannulation

    Design and Development of Patient-Specific Medical Devices for Maxillofacial Surgery Through 3D Modeling, Topology Optimization, and Additive Manufacturing

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    Additive manufacturing presents unique opportunities for developing patient-specific medical devices and tools in orthognathic surgery. Devices used in maxillofacial surgery present several constraints which refer to the specific characteristics of the patient and the stress conditions that are in place during the surgery. This paper describes an integrated workflow used for the identification, design, optimization, and production of patient-specific devices while promoting synergy among specialists of vastly different backgrounds. Medical specialist interprets Computed Tomography scans with three-dimensional reconstruction of the patient and, supported by a CAD specialist design the required tools to restore the patient functionality. Preliminary tooling designs are checked for strength and stiffness by a structural engineer considering the mechanical properties of the perspective AM materials and passed in digital form to the AM technologist who will be responsible of the 3D printing. The medical specialist uses the devices through physical prototypes to assess effectiveness and usability. The integrated workflow allows to increase accuracy while reducing surgical time and costs

    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

    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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