1,721,650 research outputs found
Comparative clinicopathologic and immunohistochemical analysis of uterine sarcomas diagnosed using the World Health Organization classification system
No full textUterine sarcomas are rare tumors that account for 3% to 7% of uterine cancers. Their histopathologic classification was revised by the World Health Organization (WHO) in 2003. The objectives of this study were to determine the frequency of different subtypes of uterine sarcoma applying the WHO criteria to a series of cases, compare the outcome of patients with different subtypes, and compare their immunoprofiles using a panel of immunomarkers. Thirty-four uterine sarcomas were identified for a 20-year period (1988-2008). Eighteen benign tumors of smooth muscle or endometrial stromal origin served as a comparison group. A tissue microarray was prepared and immunostaining performed for 10 selected oncoproteins involved in cell proliferation (Ki-67, P53, p16, and phosphatase and tensin homolog [PTEN]), cell differentiation (CD10, h-caldesmon, estrogen receptor, and progesterone receptor), and apoptosis (bcl-2 and Twist). Hierarchical clustering analysis of the immunohistochemical results was performed. The uterine sarcomas were classified as follows: 20 leiomyosarcomas, 9 endometrial stromal sarcomas, and 5 undifferentiated endometrial sarcomas. The outcome for patients with uterine sarcoma was poor, irrespective of histologic type, even for those with stage I tumors. Of the patients with follow-up available, 12 (67%) of 18 with leiomyosarcoma, 4 of 5 with undifferentiated sarcoma, and 4 of 7 with endometrial stromal sarcoma experienced recurrence and 8 patients with high-grade sarcomas died of tumor. In our series, most uterine sarcomas were leiomyosarcomas. Comparison was made between leiomyosarcomas that recurred and those with a favorable outcome and 3 patients with leiomyosarcoma without evidence of recurrence on long-term follow-up had tumors that were negative/low expressors of Ki-67, p53, p16, and Twist, with strong expression of bcl-2. A subset of undifferentiated endometrial sarcomas composed of cells with uniform nuclei may be a separate entity from those with nuclear anaplasia and may be related to low-grade endometrial stromal sarcomas. It may be possible to identify a subset of leiomyosarcomas with a favorable prognosis based on staining with a panel of immunomarkers for cell proliferation and apoptosis
Going 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
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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