1,720,969 research outputs found
Radiolabelled semisolid test meal clearance in the evaluation of esophageal involvement in scleroderma and sjogren's syndrome
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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
Prevalence and risk factors of intraoperative identification failure of sentinel lymph nodes in patients affected by breast cancer
No full textINTRODUCTION: Sentinel lymph node biopsy (SLNB) has progressively replaced complete axillary lymph node dissection in the evaluation of breast cancer patients with clinically node-negative disease. Our study investigates the rate of and risk factors involved in sentinel node identification failure. MATERIALS AND METHODS: We collected data on SLNBs performed during 2002-2010, focusing on tumor, patient, and breast characteristics, radioactivity parameters, and operators' experience. Data were analyzed by R (v2.14.2), considering significance at P values lower than 0.05. RESULTS: Among 1050 women who underwent an SLNB, the rate of identification failure was 2% (23/1050), which, on bivariate analysis, was seen to be significantly influenced (P<0.05) by the preoperative and intraoperative low radiotracer uptake (axilla/lesion radiotracer uptake ratio<1%), low level of experience of the specialist in nuclear medicine, luminal A subtype, and radiotracer uptake localization in internal mammary lymph nodes. On multivariate analysis, significant risk factors for sentinel node identification failure were found to be: axilla/lesion radiotracer uptake ratio less than 1%, radiotracer uptake localization in internal mammary lymph nodes, and luminal A subtype. Considering only the preoperative variables in our multivariate analysis, axilla/lesion radiotracer uptake ratio less than 1%, negative lymph node scintiscan, and radiotracer uptake localization in internal mammary lymph nodes had an area under the curve (receiver operating characteristic curve) of 96% (95% confidence interval 92-100%). Further, we built a nomogram based on these simple parameters for counseling the patient about the probability of not finding the sentinel lymph node during the surgical procedure. CONCLUSION: The relatively low prevalence of SLNB failure (2%) is indicative of the accuracy of the procedure when performed by experienced surgeons. The sentinel node identification failure in our population seemed to be related to biological tumor factors (luminal A subtype) and probably to physiological or pathological variations in the lymphatic drainage (axilla/lesion radiotracer uptake ratio<1% and radiotracer uptake localization in internal mammary lymph nodes). © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins
Incidence and risk factors of the intraoperative localization failure of nonpalpable breast lesions by radio-guided occult lesion localization: A retrospective analysis of 579 cases
No full textBackground: The radio-guided occult lesion localization (ROLL) technique allows the identification of nonpalpable breast lesions by means of the preoperative, intratumoral injection of a radiotracer. Our study aimed to determine the incidence and risk factors of ROLL failure. Methods: We collected data about all women who underwent ROLL in our department from 2002 to 2009, focusing on patient characteristics such as breast size and density, lesion size, localization, histology, radiologist, and surgeon experience. Data were analyzed using R v2.10.1, considering p<0.05 significant. Results: A total of 579 ROLLs were performed on 555 women with a mean age of 58.7 (±10.96) years. Incidence of ROLL failure at the first intervention was 4 % (23/579). Through monovariate analysis, ROLL failure was significantly influenced by stereotactic mammography-guided procedure, invasive tumors, pathological and radiological lesion size ≤5 mm, and the lesion's location in the central or upper breast quadrants. Through multivariate analysis, the most predictive factors for ROLL failure were as follows: lesion localization in the central quadrant, lesion radiological size <5 mm, and radiologist inexperience. Conclusions: The main risk factors for ROLL failure were the radiologist's inexperience, lesion size B5 mm, and its localization in the central subareolar quadrant, probably due to an unfavorable radiological and surgical reaching of the breast area. © Société Internationale de Chirurgie 2012
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
Applicability of two different validated models to predict axillary non-sentinel lymph node status by sentinel node biopsy in a single Italian center
No full textBackground: The necessity of complete axillary lymph node dissection (CALND) after sentinel lymph node biopsy (SLNB) for women with sentinel lymph node metastases is a matter of debate because non-sentinel lymph nodes after CALND contain no further metastases in about 50 % of cases. Our study aims to determine the applicability in our setting of two different validated nomograms to predict axillary lymph node status after SLNB. Methods: We collected data about all women who underwent SLNB in our Department of Surgery from 2007 to 2010, focusing on tumor, patient, and breast characteristics. Data was analyzed by R (version 2.15.2); p < 0.05 was considered significant. Results: Among 511 women who underwent SLNB, 126 received CALND due to sentinel lymph node metastasis, and 73.0 % of these had no further metastatic non-sentinel lymph node. The area under the receiver operating characteristic (ROC) curves for the Memorial Sloan-Kettering Cancer Center (MSKCC) nomogram and the Tenon score were 78.5 % (95 % CI 70.1–86.8 %) and 77.0 % (95 % CI 67.9–86.0 %) (p = 0.678), respectively. Conclusions: Both the MSKCC nomogram and the Tenon score were predictive for the axillary non-sentinel lymph node status by SLNB. The MSKCC nomogram was the more accurate of the two and the Tenon score was the easier one to apply
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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