1,720,989 research outputs found
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
SCIP flap in head and neck reconstruction after oncologic ablative surgery: a systematic review
Full text linkBackground In the surgical treatment of head and neck locally advanced malignancies, microvascular free flaps represent the most valuable solution to reconstruct the tissue defect after resection of the primary neoplasm. In particular, microvascular free flaps allow to restore the functional and aesthetical features of the head and neck compartments. The superficial circumflex iliac perforator (SCIP) flap represents, as an evolution of the groin flap, a valid alternative to the radial fasciocutaneous free (RFFF) flap or the anterolateral thigh (ALT) flap.Methods This systematic review adhered to the recommendations of the Preferred Reporting Items of Systematic Reviews and Meta-analysis (PRISMA) 2009 guidelines. A computerized MEDLINE search was performed using the PubMed service of the U.S. National Library of Medicine (www.pubmed.org) and Scopus database (www.scopus.com). Two authors screened the articles, then selected and extracted data on malignancies characteristics, reconstructive techniques, outcomes, and complications.Results A total of 25 articles were selected and reviewed among the 39 identified through the search string. Six out of the selected 25 articles were case reports, while the remaining 19 articles were retrospective case series. The whole study population was represented by 174 oncologic patients undergoing ablation of a head and neck tumor and reconstruction with a SCIP flap. The site of reconstruction was the oral cavity in 125 (71.0%) patients, being the tongue the most common subsite in 73 (41.5%) patients, the pharynx in 10 (5.7%) cases, the larynx in 3 (1.7%) and head and neck skin in 36 (20.4%) patients. Only two cases of total flap loss were reported. Partial flap loss or shrinkage requiring minor surgical revisions was observed in 11 patients (6.32%). Primary closure of the donor site was achieved in the whole study population, according to the available data.Conclusions In head and neck postoncological reconstruction, despite the caliber and the length of the pedicle, SCIP flap offers a pliable and thin skin paddle, allowing single-stage resurfacing, medium to large skin paddle, possibility of composite-fashion harvest and a well-concealed donor site
Facial sinus endoscopic evaluation, radiologic assessment, and classification
Full text linkObjectives: To describe facial sinus anatomy from an endoscopic perspective and present a radiologic classification. Methods: Facial sinus was studied by endoscopy and high-resolution computed tomography (HRCT) scan in 39 temporal bones that underwent exclusive transcanal endoscopic approach. A radiomorphologic classification based on the relationship between the facial sinus and the mastoid portion of the facial nerve is created as follows. In type A facial sinus, the pneumatization of the facial sinus did not extend medially or posteriorly to the mastoid portion of the facial nerve. In type B facial sinus, the pneumatization extended posteriorly to the mastoid portion of the facial nerve. In type C facial sinus, the pneumatization extended posteriorly and medially to the mastoid portion of the facial nerve. Results: In all the specimens that underwent HRCT (n = 31), facial sinus could be identified, and its depth classified, in relation to the facial nerve. In this group, 58% type A, 29% type B, and 13% type C facial sinuses were identified. In all the specimens (n = 39), the facial sinus could be assessed by means of an exclusive endoscopic transcanal approach, and anatomical variants of the chordiculus, previously known as chordal ridge, could be described: ridge (39%), bridge (18%), incomplete (15%), and absent (28%). Conclusion: Endoscopic exploration of the retrotympanum guarantees a very good exposure of the facial sinus, allowing detailed anatomic descriptions of its conformation and relationships with other structures. Improvement in our knowledge of its anatomy might decrease the possibility of residual disease during cholesteatoma surgery. Angled endoscopes (e.g. 45 °, 70 °) can guarantee a better view of the facial sinus. Level of Evidence: NA. Laryngoscope, 128:2397–2402, 2018
Novel Surgical and Radiologic Classification of the Subtympanic Sinus: Implications for Endoscopic Ear Surgery
Full text linkObjective: The aim of this study is to describe the endoscopic anatomy of the subtympanic sinus (STS), establish a classification according to its extension regarding the level of the facial nerve (FN), and assess the feasibility of the transcanal endoscopic approach to the STS. Study Design: Experimental anatomic research. Setting: Temporal bone laboratory. Methods: We performed endoscopic dissection of 34 human whole head and ear block specimens. Of those, 29 underwent high-resolution computed tomography. The STS was classified according to its extension regarding the level of the FN: type A, no extension medial to the FN; type B, extension to the medial limit of the FN; type C, extension of the sinus medially and posteriorly from the FN into the mastoid cavity. Results: The majority of cases (n = 21, 72%) showed a shallow type A STS. We observed a deep type B configuration in 6 cases (21%) and a type C in 2 cases (7%). The STS was completely exposable with a 0° endoscope in 44% of the specimens. Using a 45° endoscope, we gained complete insight in 79%. However, in 21% of the cases, the posteromedial extension of the STS was too deep to be completely explored by an endoscopic transcanal approach. Conclusion: The majority of the STS is shallow and does not extend medially from the FN. This morphologic variant allows complete transcanal endoscopic visualization. In more excavated STS, a complete endoscopic exploration is not achievable, and a retrofacial approach may be adopted to completely access the STS
An Integrated (Microscopic/Endoscopic) Dissection Ear Surgery Course
No full textTraditionally, otologic surgical training consisted of microscopic cadaveric dissections. However, during the last decades the endoscope has significantly changed the surgical perspective in the otologic field. Thus, the modern ear and lateral skull base surgeon should master the entire spectrum of endoscopic and microscopic approaches, with the aim of tailoring the procedure and guaranteeing the best possible functional outcome. This work proposes a step-by-step guided and illustrated dissection course, including indications for the setup of the cadaver lab and the integration of the microscope and endoscope to enhance the use of both instruments. The alternation of the endoscope and microscope allows the novice to train the correct handling of the instruments in the surgical field under both optical views. This aspect is of utmost importance since it is not advisable to start off a technique without practicing the other one, as both are important and complementary in the modern otologic surgery setting
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
The variants of the retro- and hypotympanum: an endoscopic anatomical study
Full text linkThe retro- and hypotympanum are hidden areas of the middle ear, only poorly recognized. Nevertheless, this region is of relevant clinical significance, since it is regularly affected by disease such as cholesteatoma. The aim of this study is to explore and describe the anatomical variants of the hypo- and retrotympanum by the means of transcanal endoscopy. We hypothesize a significant variability of this hidden region of the middle ear. Moreover, we believe that the minimal invasive, endoscopic access is suitable since angled scopes may be used to explore the region. To this end a total of 125 middle ears (83 cadaveric dissections, 42 surgical cases) were explored by the means of 3Â mm straight and angled scopes. The variants were documented photographically and tabularized. The bony crests ponticulus, subiculum and finiculus were most frequently represented as ridges. The ponticulus showed the highest variability with 38% ridge, 35% bridge and 27% incomplete presentation. The subiculum was bridge-shaped only in 8% of the cases, the finiculus in 17%. The sinus tympani had a normal configuration in 66%. A subcochlear canaliculus was detectable in 50%. The retro- and hypotympanum were classified, respectively, to the present bony crests and sinus in a novel classification type IâIV. In conclusion, we found abundant variability of the bony structures in the retro- and hypotympanum. The endoscopic access is suitable and offers thorough understanding and panoramic views of these hidden areas
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