1,721,353 research outputs found
Frontal Sinus Osteoma Complicated by Extended Intracranial Mucocele and Cerebral Abscess: Neurosurgical Strategy of a Rare Clinical Entity
No full textThe combination of paranasal sinus osteoma, mucocele and brain abscess is rare. Only one other case has been reported so far, where the cerebral abscess was diagnosed intraoperatively. We report here on a second patient with combined frontal sinus osteoma, intracerebral mucocele as well as cerebral abscess. However, in our case, the diagnosis of cerebral abscess was reached prior to surgery, which allowed for a tailored treatment strategy with abscess puncture under neuronavigational guidance and, after 3 weeks of antibiotic therapy with documented abscess shrinkage, osteoma and mucocele resection as well as reconstruction of the eroded dura
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
A Radiologic Score to Distinguish Autoimmune Hypophysitis from Nonsecreting Pituitary Adenoma Preoperatively
No full textBACKGROUND AND PURPOSE: Autoimmune hypophysitis (AH) mimics the more common nonsecreting pituitary adenomas and can be diagnosed with certainty only histologically. Approximately 40% of patients with AH are still misdiagnosed as having pituitary macroadenoma and undergo unnecessary surgery. MR imaging is currently the best noninvasive diagnostic tool to differentiate AH from nonsecreting adenomas, though no single radiologic sign is diagnostically accurate. The purpose of this study was to develop a scoring system that summarizes numerous MR imaging signs to increase the probability of diagnosing AH before surgery. MATERIALS AND METHODS: This was a case-control study of 402 patients, which compared the presurgical pituitary MR imaging features of patients with nonsecreting pituitary adenoma and controls with AH. MR images were compared on the basis of 16 morphologic features besides sex, age, and relation to pregnancy. RESULTS: Only 2 of the 19 proposed features tested lacked prognostic value. When the other 17 predictors were analyzed jointly in a multiple logistic regression model, 8 (relation to pregnancy, pituitary mass volume and symmetry, signal intensity and signal intensity homogeneity after gadolinium administration, posterior pituitary bright spot presence, stalk size, and mucosal swelling) remained significant predictors of a correct classification. The diagnostic score had a global performance of 0.9917 and correctly classified 97% of the patients, with a sensitivity of 92%, a specificity of 99%, a positive predictive value of 97%, and a negative predictive value of 97% for the diagnosis of AH. CONCLUSIONS: This new radiologic score could be integrated into the management of patients with AH, who derive greater benefit from medical as opposed to surgical treatment
Preprocedural C-reactive protein levels predict stroke and death in patients undergoing carotid stenting
No full textBackground and Purpose: Elevated baseline levels of C-reactive protein (CRP) are associated with an adverse outcome during coronary stent placement. The aim of this study was to evaluate whether preprocedural CRP levels also are predictive of stroke and death in patients undergoing carotid stent placement (CAS). Materials and Methods: We reviewed data prospectively collected from 130 patients (97 men, 33 women; mean age, 68.5 +/- 10.1 years; range, 43-89 years) who underwent CAS for symptomatic carotid stenosis and from whom preprocedural CRP values had been obtained. A CRP value of >5 mg/L was considered to be elevated. The frequency of stroke and death within 30 days was compared between patients with and without elevated baseline CRP levels using chi(2) and multivariate logistic regression analysis. Results: Baseline CRP values were normal in 94 (72.3%) patients but were elevated in 36 (27.7%) patients. The demographic and clinical characteristics were similar in both treatment groups. The 30-day stroke and death rate was significantly higher in patients with elevated CRP values (8/36; 22.2%) than in those without (3/94; 3.2%; P < .01). After adjusting for demographic characteristics, degree of carotid stenosis, and use of cerebral protection devices and/or statin therapy, an elevated CRP value before CAS remained a significant and independent predictor of stroke and death within 30 days after CAS (odds ratio, 7.7; 95% confidence interval: 1.8-32.8, P = .006). Conclusions: Baseline CRP is a powerful predictor of outcome in patients undergoing CAS, which underscores the role of inflammation in the pathogenesis of embolic complications during this procedure
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
- …
