1,721,042 research outputs found
Endoscopic endonasal clipping of a ruptured vertebral-posterior inferior cerebellar artery aneurysm: technical case report
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Management of cerebrospinal fluid leaks according to size. Our experience
No full textObjective: We present our experience in the reconstruction of cerebrospinal fluid (CSF) leaks according to their size and location. Material and methods: Fifty-four patients who underwent advanced skull base surgery (large defects) and 62 patients with CSF leaks of different origin (small and medium-sized defects) were included. Large defects were reconstructed with a nasoseptal pedicled flap positioned on fat and fascia lata and lumbar drainage was used. In small and medium-sized leaks of other origin, intrathecal fluorescein 5% was applied previously to identify the defect. Fascia lata in an underlay position was used for reconstruction, which was then covered with mucoperiosteum from the turbinate. Perioperative antibiotics were administered for 5-7 days. Nasal packing was removed after 24-48 hours. Results: The most frequent aetiology for small and medium-sized defects was spontaneous (48.4%), followed by trauma (24.2%), iatrogenic (5%) and others. The success rate was of 91% after the first surgery and 98% in large skull base defects and small/medium-sized respectively. After rescue surgery, the rate of closure achieved was 100%. The follow-up was 15.6 +/- 12.4 months for large defects and 75.35 +/- 1.3 months for small/medium-sized defects without recurrence. Conclusions: Endoscopic surgery for closure of any type of skull base defect is the gold standard approach. Defect size does not play a significant role in the success rate. Fascia lata and mucoperiosteum allow a reconstruction of small/medium-sized defects. For larger skull base defects, a combination of fat, fascia lata and nasoseptal pedicted flaps provide a successful reconstruction. (C)2013 Elsevier Espana, S.L. All rights reserved
Neurosurgeon-otolaryngologist collaboration in endonasal approaches to the clivus and suprasellar region
No full textGoing Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Endoscopic endonasal surgery for skull base tumours: technique and preliminary results in a consecutive case series report
No full textBackground: The introduction of the endoscope in transsphenoidal surgery has allowed access to lesions located in complex regions of the skull base under direct visual control. With the application of this technique, our group started treating pituitary tumours and from 2009 onwards began treating skull base lesions through extended endoscopic endonasal approaches. The aim of the present study is to report our experience with extended endoscopic approaches. Indications, results, limitations and complications of this new technique are also discussed. Material and methods: From January 2007 to January 2012, the endonasal approach was used in 40 patients with different cancerous lesions. Results: Total tumour removal, as assessed by postoperative magnetic resonance imaging, occurred in 30/40 patients (75%), but in 10 patients only partial removal was possible. Major complications, including cerebrospinal fluid leak, were observed in 5/40 patients (8%). One patient died 3 months after surgery due to a severe systemic sepsis. Conclusion:The extended endoscopic endonasal approach could be used as a minimally invasive and innovative technique for the removal of selected skull base lesions
Variations on the Author
Get PDF“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
Get PDFWe 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
Get PDFWe 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
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