1,720,967 research outputs found
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
Papillary thyroid carcinoma in thyroglossal duct cyst: Case reports and literature review
No full textAlthough thyroglossal duct cysts represent a common developmental abnormality of the thyroid gland, malignant transformation is rare and occurs in only 1% of cases. This article describes four clinical cases observed at the Surgical Science Department of "La Sapienza" University of Rome between 1996 and 2000. Histologic examination indicated two pure papillary carcinomas, a sclerosing papillary carcinoma, and a follicular variant of papillary carcinoma. In all cases, treatment involved removal of the body of the hyoid bone and total thyroidectomy, which we associated with removal of the thyroglossal duct cyst. In one case, laterocervical lymphectomy was performed. Carcinoma multifocality was found in one patient. We recommend associating total thyroidectomy with removal of the tumor of the thyroglossal duct and of the body of the hyoid bone, because the carcinoma may be multifocal and there may be lymphatic invasion of the thyroid and to ensure a correct follow-up
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
Analysis of prognostic factors for the indication of central lymphadenectomy in papillary thyroid carcinomas.
No full textBACKGROUND: In this study we examined whether it was possible following preoperative parameters statistically significant correlation with the presence of metastatic lymph nodes in the papillary thyroid carcinoma. We conducted a retrospective study in a group of patients with a preoperative diagnosis of papillary carcinoma who underwent total thyroidectomy associated with routine lymphadenectomy of the central compartment (level VI). PATIENTS AND METHODS: The study group consisted of patients whose definitive histological lymph node examination was positive for metastasis (N1), and the control group comprised patients found negative for metastasis (N0). RESULTS: Tumour diameter had a significance at 10% level [Pr(>|z|): 0.056], thus indicating that increased tumour size results in a higher probability of being in group N1. The logistic regression revealed that variables with a significance at 5% level for the presence of metastatic lymph nodes in the central compartment (N1) were: sex [Pr(>|z|): 0.019], overall patient age [Pr(>|z|): 0.012] and age >45 [Pr(>|z|): 0.022]. We performed a statistical analysis with the association of three preoperative variables (presence of ultrasound-revealed microcalcifications, presence of solid hypoechogenic nodule and type III vascularisation on echocolour-Doppler); this was found to result in a highly significant probability of entering into group N1. CONCLUSIONS: We found variables statistically significant for the presence of metastatic central compartment lymph nodes, including female sex, age >45 yrs and tumour diameter >1.5 cm. The association of papillary carcinoma with microcalcifications, solid hypoechogenic nodule structure and type III vascularisation on echocolour-Doppler also resulted in a statistically significant increase in the probability of positive level VI lymph nodes
Prognostic importance of sclerosing variant in papillary thyroid carcinoma
No full textThe diffuse sclerosing variant (DSV) of papillary thyroid carcinoma is known for its high aggressiveness, high incidence of lymph node metastases, and high incidence of pulmonary metastases, and thus its consequently poorer prognosis. In this study, we undertook a retrospective analysis of papillary thyroid carcinomas to assess whether DSV can be considered a predictive factor for prognosis. We performed a retrospective evaluation of the Department's database of patients with papillary thyroid carcinoma who had undergone total thyroidectomy from January 1992 to December 2000. Group I consisted of 83 DSV patients and Group II was 168 pure papillary carcinoma (PC) patients. A significant prevalence of multinodular thyroid disorder on diagnosis was found for PC (P < 0.05), whereas with DSV, there was a significantly higher prevalence of post-thyroiditis nodular thyroid disorder than with PC (P < 0.001). The incidence of laterocervical lymph node pathology on diagnosis was significantly higher for DSV (P < 0.05). In 3.6 per cent of PC patients and 15.7 per cent of DSV patients, we observed recurrences in the regional lymph nodes (P < 0.001). We found 1.2 per cent distant metastases in PC patients and 7.2 per cent in DSV patients (P < 0.05). One PC patient (0.6%) and three DSV patients (3.6%) died of tumor-related causes (P < 0.05). Our study demonstrated that diffuse sclerosing carcinoma leads to a poorer prognosis to the extent that its classification as an autonomous clinical pathological entity is justified. In conclusion, we can state that DSV is a form of papillary thyroid tumor characterized by its higher aggressiveness, diffuse intrathyroid growth, and high incidence of lymph node and pulmonary metastasis. Ultimately, this means a poorer prognosis. In the presence of risk factors indicating a possible increase in biological aggressiveness, adequate postoperative treatment and close follow-up become essential
Sclerosing papillary carcinoma arising in a lingual thyroid: Report of a case
No full textEctopic lingual thyroid tissue is an uncommon congenital anomaly. Tumors with identical pathological characteristics to those arising in thyroid tissue may be present in ectopic locations, but there are very few cases of malignant ectopic thyroid tumors reported in the literature. We present a review of this phenomenon and report a case of papillary carcinoma of the base of the tongue, located in ectopic lingual thyroid tissue, in a 30-year- old woman. The patient's presenting symptoms were dysphagia and oral bleeding, and we performed radical resection of the neoformation at the base of the tongue with part of the muscles of the floor of the mouth and the body of the hyoid bone, as well as total thyroidectomy. Histological examination revealed a "sclerosing" papillary carcinoma. The patient was treated with I-131 and substitutive thyroid hormonal therapy. An ultrasonogram done 5 years later showed bilateral laterocervical lymph node recurrence, which was effectively treated with bilateral laterocervical lymphectomy
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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