1,720,954 research outputs found
Ricerca della mutazione BRAFV600E e del riarrangiamento RET/PTC negli agoaspirati tiroidei in pazienti sardi
No full textSearch of BRAFV600E mutation and RET/PTC rearrangement in thyroid fine-needle aspiration
biopsies in sardinian patients. In recent years, the use combined of molecular biology techniques
with traditional cytology allowed the study of the expression pattern of oncogenes involved in the genesis of papillary
thyroid carcinoma. In this prospective study, the prevalence of BRAFV600E mutation and the RET/PTC1 rearrangement
were evaluated in 260 thyroid fine-needle aspiration biopsies (FNAB), and the results compared with the cytological and
histological diagnosis. The study also aimed to ascertain whether the frequency and the diagnostic value of these
molecular markers in the Sardinian population (showing genetic peculiarities), differ from those of other series from other
geographical areas. In 32 nodules with malignant or suspect cytology (all surgically treated, of whom 29 [90,6%]
malignant) BRAFV600E mutation was found in 12 patients (37,5%) and RET/PTC1 in 3 patients (9,4%). In contrast, no
mutation was found in nodules with indeterminate (n=43), benign (n=62) and inadequate (n=20) cytology, although of 33
operated patients of this group, 8 (24.2%) had histologically confirmed malignant tumors. These results confirm that the
presence of BRAFV600E and RET/PTC1 in thyroid FNAB is highly specific of malignancy, although the test does not attain
sufficient diagnostic sensitivity if only these oncogenes are sought. Finally, comparison with previously published studies
shows that the frequency of BRAFV600E and RET/PTC1 in thyroid FNAB from Sardinian patients is similar to that reported
in most other geographical areas
RET proto-oncogene in Sardinia: V804M is the most frequent mutation and may be associated with FMTC/MEN-2A phenotype
No full textOBJECTIVE:
Genetic screening of RET proto-oncogene is a powerful tool for the early identification of familial cases of medullary thyroid carcinoma (MTC), comprising isolated familial thyroid medullary carcinoma (FMTC) and multiple endocrine neoplasia syndromes 2A (MEN-2A) and 2B (MEN-2B). We report the results obtained by RET mutation analysis of subjects living in Sardinia, an Italian island whose inhabitants display a peculiar genetic background due to geographic isolation and low immigration rate for several centuries.
DESIGN:
Retrospective study reporting data on 67 patients referred during the last 5 years for RET analysis because affected by MTC or first degree relatives of MTC patients.
MAIN OUTCOME:
Only three mutations were identified affecting codons 620 (exon 10), 634 (exon 11), and 804 (exon 14); surprisingly, the most prevalent mutation found was V804M (overall prevalence: 59%). This finding is quite different from previous studies carried out in other Caucasian and non-Caucasian populations, in which the frequency of the V804M mutation is consistently reported less than 5%. The phenotype associated to V804M mutation was mostly FMTC (16/17 cases = 94.1%), but in one case (5.9%) primary hyperparathyroidism was found, suggesting a MEN-2A.
CONCLUSIONS:
These results underline the importance of the genetic background in the distribution of RET mutations and should be taken into consideration when performing genetic evaluation of MTC patients
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
- …
