1,721,054 research outputs found
Flow Cytometric Analysis In Squamous Cell Head and Neck Cancers - Invivo Evaluation By Using Bromodeoxyuridine Evaluation
No full textProliferative Characteristics of Head and Neck Tumors - In-vivo Evaluation By Bromodeoxyuridine Incorporation and Flow-cytometry
No full textCell proliferation of head and neck cancers was studied in 52 patients using in vivo bromodeoxyuridine (BUDR) incorporation. Patients received 250 mg BUDR intravenously several hours prior to biopsy of the tumor tissue. Bivariate flow cytometry was used and enabled us to rapidly obtain DNA ploidy, labelling index (LI), DNA synthesis time (TS) and tumor potential doubling time (Tpot). This method was found to be suitable to obtain complete cytokinetic data in 46/52 (88.5%) patients. The mean BUDR LI was 7.9% (range 2-18%); mean TS was 11.6 h (range 6-28.5 h); mean Tpot was 5.7 days (range 2-30 days). BUDR LI and TS were significantly correlated with histological differentiation grading: G(3) tumors showed higher LI values and shorter TS values than G(1)/G(2) tumors. A similar correlation was found between LI or TS and tumor dimensions. Tpot was also significantly lower in larger tumors, such as in those with a higher grading. No significant correlation was found between LI or TS and DNA ploidy (50% of the tumors in our series were DNA aneuploid), while Tpot was found to be 10 days in diploid tumors, compared to only 6.3 days for the aneuploid tumors (p < 0.05). All cases with documented lymph node involvement (N+) showed significantly higher LI, and shorter TS and Tpot values if related to nodal free ones (Tpot = 10 days in N+ patients and 6.3 days in N- patients; p < 0.05). The results of this study suggest that the method employed is clinically feasible and could be a useful aid in defining the prognosis of head and neck cancer patients. Since cell kinetic information is readily available using this method, it could be incorporated into clinical trials to improve the design of therapeutic strategies for cancer patients
Invitro Evaluation of Multiple Kinetic-parameters In Human-leukemia By Quantitative C-14 Autoradiography
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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
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