1,720,981 research outputs found
Technological improvements in the treatment of haemorrhoids and obstructed defaecation syndrome
No full textRandomised clinical trial of adjuvant postoperative RT vs. sequential postoperative RT plus 5-FU and levamisole in patients with stage II-III resectable rectal cancer: a final report.
No full textA randomised clinical trial was performed in patients undergoing radical surgery for rectal cancer to compare the efficacy and toxicity of adjuvant postoperative radiation therapy (RT) to sequential RT and chemotherapy (CT) with 5-fluorouracil (5-FU) plus levamisole (LEV). The primary end point was overall survival (OS); secondary end points were disease-free survival (DFS), the rate of loco-regional recurrence, and treatment-related toxicity; the final results of this trial are reported.Patients in arm I underwent RT (50 Gy) in daily fractions of 2 Gy, 5 days/week for 5 weeks. Patients in arm II began with 5-FU (450 mg/sqm/day intravenous (i.v.) bolus, days 1-5) plus LEV (150 mg/day orally, days 1-3); postoperative RT was delivered during week 2 at the same dosage and schedule as in arm I. The other five cycles of CT (5-FU every 28 days and LEV every 15 days for the length of 5-FU administration) continued after the end of RT if clinical and hemato-biochemical parameters were in the normal range.From May 1992 to December 1998, 218 patients were enrolled into the randomised clinical trial (144 men, 74 women; age range: 28-75, median 64 years). The median follow-up time was 58.1 months (range: 1-3,271 days). No significant difference was observed between the two arms of treatment as regards OS and DFS (P = 0.18 and P = 0.66, respectively). Cox regression analysis for OS confirmed what was observed by univariate analysis for all variables except age. Older age (>60 years) and pathologic lymph-node involvement defined the subgroups with the worst prognosis. Cox regression analysis for DFS confirmed what was observed by univariate analysis for all variables: the only independent variable in predicting DFS was pathologic lymph-node involvement.Our findings suggest no difference in OS, loco-regional and distant site progressions of postoperative RT alone compared to sequential postoperative RT and CT; notably, this latter regimen was associated with higher toxicity which seriously impaired the patient's compliance to CT. The low loco-regional recurrence rate (9.2\%) observed in our patients undergoing postoperative RT alone compared to similarly treated patients in previously performed clinical trials (20-25\%) underline the role of radical surgery (mesorectal excision) coupled with a complete postoperative RT regimen. On the other hand, the similar efficacy of these two adjuvant modalities of treatment might be conditioned by both the low compliance (59\%) to the CT regimen as well as the sequential, instead of concurrent, schedule of administration of RT and CT, which may have decreased further the expected efficacy of the combined regimen
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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