1,720,956 research outputs found
Elastography in the diagnosis of breast lesions: comparison of different elastographic features
No full textBackground Breast elastography is a non-invasive and widely accessible method used in the differential diagnostic procedure in addition to B-mode imaging. Purpose To assess the role of elastographic features in the differentiation of breast lesions and to evaluate the importance of depth in the choice of reference fat tissue for the calculation of strain ratio. Material and Methods From January to August 2015, 242 breast lesions were evaluated using elastographic assessment based on qualitative and semi-quantitative parameters (color map, strain ratio, length ratio) as well as elastographic analysis. Histological findings were considered as gold-standard. Results Sensitivity and specificity of B-mode ultrasound imaging were 90% and 60%, respectively. Color map sensitivity was 98% and specificity 46%; strain ratio sensitivity 81% and specificity 70%; length ratio sensitivity 64% and specificity 76%. Combined analysis of these three elastographic features improved the overall diagnostic performance of any of the three parameters alone, yielded sensitivity similar to that of color map (95%) and specificity comparable to strain ratio and length ratio (70%). There was no significant difference in strain ratio obtained from the reference fat tissue at the same depth as the lesion and at a different depth (sensitivity 77% versus 84%; specificity 70% versus 68%; P < 0.001). Conclusion In our experience, elastography can improve ultrasound characterization of the lesion, particularly if elastographic analysis is performed
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
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
Is pattern III as evidenced by US Color-Doppler useful in predicting thyroid nodule malignancy? Large-scale retrospective analysis
No full textObjective. To evaluate whether pattern III of color Doppler Ultrasound may identify malignant nodules. Materials and Methods. We have retrospectively analyzed data pertaining to 1090 patients of both genders (230 males, 860 females), with an average age of 53 years (min 17 years, max 81 years), who underwent thyroidectomy in Department of Surgical Sciences of Sapienza University of Rome since January 2003 through June 2009. We correlated color-Doppler characteristics and histological features through statistical analysis so as to verify statistical correlation between them. Results. Our study showed that 164/273 (60.1%) patients with malignant disease were associated with vascularization pattern III. Regarding benign disease, 152/268 (56.7%) patients showed a pattern of vascularization 3 at ultrasonography. The statistical analysis was not able to show any correlation between pattern III and malignancy. Conclusion. Pattern 111 cannot be used to predict malignancy with confidence, and FNA is still mandatory to rule out the nature of the nodule. Clin Ter 2010; 161(2):e49-e5
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