1,721,003 research outputs found
[The thyroid nodule. Diagnostic considerations].
No full textThyroid nodule is extremely common. Its prevalence has been estimated to be more than 5% in the adult population. If thyroid nodule is a rare condition, 0.004% a year, identifying those nodules, which are likely to be malignant, is very important for physicians. The evaluation of thyroid is carried out using the fine needle aspiration biopsy (FNAB), the ultrasonography, and scanning with 131I and 99Tc. Before FNAB thyroid scans was the most common test in clinical evaluation of thyroid nodules, used to identify "hot" and "cold" lesions. Hot or warm nodules, about 5%, are seldom malignant, whereas cold or hypofunctional have a 10% to 25% chances of being malignant. FNAB is the elected laboratory test: this procedure is easily, simple, non traumatic, and very acceptable to the patients. Ultrasound is useful in several settings: it provides a non invasive and relatively inexpensive means of following the size of nodule, after medical therapy and FNAB
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
Il nodulo autonomo - Aspetti clinici
No full textAutonomously functioning thyroid nodule (AFTN) includes a wide spectrum of unique or multifocal diseases, either hyper or euthyroid, which share the same independence from thyroid stimulating hormone (TSH) regulation in terms of growth and function. The pathological basis and the recent molecular implications of the disease are briefly discussed. Clinical and epidemiologic data of 1572 patients with AFTN, out of a population of 14107 patients with thyroid diseases, sequentially evaluated from 1974 to 1992, have been retrospectively examined. The mean age of AFTN occurrence is 41 years and it appears more frequently in women (F/M = 5.3/1). Clinical hyperthyroidism occurs only in 17% of patients and is more frequently observed in men over 40 years of age. The presence of sonolucent area inside the nodule is detectable in 8.6% of cases and may be associated with spontaneous arrest of growth. When AFTN is submitted to cytologic evaluation, patterns similar to those observed in nodular goiter are shown (colloid lesion, cyst and nodular hyperplasia). Signs of hyperactivity are also shown by follicular cells. In the presence of a cyst, a fine needle aspiration was performed and a complete resolution was observed in 40% of cases. When cyst recurred after aspiration, a solution of tetracycline was inserted into the cavity. Sclerosing therapy was efficient in evacuating the volume of the nodule in 50% of the cases. Patients with AFTN were followed for a mean period of 61 months and 84.7% of them did not show any morphological or functional change, while the remaining 15.3% of cases became hyperthyroid
Diagnostic accuracy of conventional versus sonography-guided fine-needle aspiration biopsy of thyroid nodules.
No full textFine-needle aspiration biopsy (FNAB) is an accurate, slightly invasive, and safe method for the preoperative diagnosis of thyroid nodules. Recently, ultrasound guidance has been suggested as a valuable aid to enhance FNAB diagnostic performance. In this study, we have compared diagnostic accuracy of conventional FNAB (C-FNAB) versus sonography-guided FNAB (SG-FNAB) on a large sample population of 9683 patients with thyroid nodules. Over a 15-year period, 4986 patients were investigated by C-FNAB and 4697 underwent SG-FNAB. A valid cytological diagnosis was obtained in 85.9% of C-FNAB and in 91.5% of SG-FNAB cases, allowing detection of thyroid cancer in 1.6% and 2.1% of patients, respectively. The indeterminate pattern of follicular neoplasia was observed in 238 C-FNAB (5%) and in 272 (5.4%) SG-FNAB nodules. Specimens were cytologically inadequate in 433 C-FNAB (8.7%), but only in 167 SG-FNAB cases (3.5%). A total of 535 C-FNAB and 540 SG-FNAB nodules underwent surgery. False-negative results occurred in 7 C-FNAB nodules (2.3%), but only in 3 SG-FNAB cases (1%). Sensitivity, specificity, and global diagnostic accuracy of C-FNAB compared with SG-FNAB were 91.8% versus 97.1%, 68.8% versus 70.9%, and 72.6% versus 75.9%, respectively. Our results, based on a large population of thyroid nodules, demonstrate that SG-FNAB allows a more precise and adequate sampling of thyroid nodular lesions and is associated with a lower rate of false-negatives, thus improving global diagnostic accuracy in the preoperative selection of thyroid cancer
[Post-operative hypothyroidism].
No full textHypothyroidism is not a rare condition, since it represents about 10% of thyroid diseases. It is more frequent in women (F/M = 5/1), and in patients older than 60 years of age. Postoperative hypothyroidism is secondary to thyroidectomy, and the incidence varies, with a reported range between 14% and 75%. This may be related to the amount of thyroid removed, the experience of the surgeon, age of patient, the function of remaining thyroid, and duration of postoperative observation. The analysis of our cohort of more than 23,000 thyroid patients showed a prevalence of hypothyroidism of 11.1%. Postoperative hypothyroidism represents about 39.7% of all hypothyroid cases, and 44% of patients underwent surgery. The prevalence is six fold higher in patients over the age of 60. Factors favoring development are the presence of lymphocytic infiltration of the thyroid and a positive serological test for thyroid antibodies. Overt hypothyroidism represented the largest proportion, prevailing in 60% of postoperative hypothyroid patients. In view of the insidious development of postoperative hypothyroidism in some patients, an accurate follow-up should be required, allowing an opportune treatment with LT4
Pre- and post-construction characterization of an embankment fill material
No full textEach compaction method significantly affects the engineering properties of compacted soils by producing its own distinctive internal structure. Independently of the mechanics and type of compaction energy applied in field, the design requirements for embankments construction should satisfy standard Proctor moisture-density criteria. The aim of this paper is to investigate the pre- and post-construction strength of a clayey silt used as fill material on an experimental embankment built along the Po river, Italy. After seven years of the embankment construction, undisturbed specimens were obtained from the embankment body. Suction controlled triaxial test were conducted on the retrieved samples in order to determine the post-construction shear strength. The results have been compared with the obtained by Vasallo (2003) on samples compacted by using standard Proctor method. The experimental procedures, the post-construction results and the comparison with the pre-construction parameters are presented and discussed in the paper
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