1,720,955 research outputs found
99mTc-MIBI radio-guided minimally invasive parathyroidectomy: experience with patients with normal thyroids and nodular goiters
No full textThe surgical approach to primary hyperparathyroidism (HPT) is changing. In patients with a high probability to be affected by a solitary parathyroid adenoma (PA), a unilateral neck exploration (UNE) or a minimally invasive radio-guided surgery (MIRS) using the intraoperative gamma probe (IGP) technique have recently been proposed. We investigated the role of IGP in a group of 84 patients with primary HPT who were homogeneously evaluated before surgery by a single-day imaging protocol including 99mTcO4/MIBI subtraction scan and neck ultrasound (US) and then operated on by the same surgical team. Quick parathyroid hormone (QPTH) was intraoperatively measured in all cases to confirm successful parathyroidectomy. In 70 patients with scan/US evidence of a single enlarged parathyroid gland (EPG) and with a normal thyroid gland, MIRS was planned. In the other 14 patients, the IGP technique was utilized during a standard bilateral neck exploration (BNE) because of the presence of concomitant nodular goiter (11 cases) or multiglandular disease (MGD) (3 cases). The IGP technique consisted of the following: (1) in the operating room, a low 99mTc-MIBI dose (37 MBq) was injected intravenously during anesthesia induction; (2) subsequently, the patient's neck was scanned with the probe by the surgeon to localize the cutaneous projection of the EPG; (3) in patients who underwent MIRS, the EPG was detected intraoperatively with the probe and removed through a small, 2 to 2.5 cm skin incision; (4) radioactivity was measured on the EPG both in vivo and ex vivo, the thyroid, the background and the parathyroid bed after EPG removal. In patients with concomitant nodular goiter, the radioactivity was also measured on the thyroid nodules. Surgical and pathologic findings were consistent with a single PA in 78 patients, parathyroid carcinoma in 2, and MGD in 4. MIRS was successfully performed in 67 of the 70 patients (97.7%) in whom this approach was planned. It must be pointed out that the IGP technique was particularly useful in detecting the PAs located in ectopic site (5 in the upper mediastinum, 2 at the carotid bifurcation) and deep in the neck (6 in the paratracheal/paraesophageal space). Moreover, MIRS was also successfully performed in the seven patients who had undergone previous parathyroid or thyroid surgery. In the other 3 of 70 patients (4.3%), a conversion to BNE was required because a parathyroid carcinoma (2 cases) and a MGD (1 case) were diagnosed during surgical intervention. It is worth noting that in this latter patient affected by MGD, in contrast with the other patients from our series, QPTH remained elevated after the removal of the preoperatively visualized EPG suggesting the persistence of occult hyperfunctioning parathyroid tissue, and another contralateral EPG was found at BNE. Regarding the group of patients in whom a BNE was planned, the IGP helped the surgeon to localize a supernumerary EPG ectopic in the thymus in a patient with MGD, and to localize a PA ectopic to the right carotid bifurcation in a patient with nodular goiter. However, it has to be pointed out that it was difficult for the surgeon to differentiate intraoperatively with the probe the radioactivity of the EPG from that of thyroid nodule(s) in the other 10 patients with HPT with a concomitant nodular goiter, particularly in 6 patients in whom 99mTc-MIBI uptake was higher in thyroid nodule(s) than in EPG. On the basis of these data we can conclude that: (1) in patients with primary HPT with a high scan/US probability to be affected by a single PA and with a normal thyroid gland, IGP appears to be an useful technique with the aim of performing MIRS; (2) a 99mTc-MIBI dose as low as 37 MBq appears to be adequate to successfully perform MIRS; (3) the measurement of QPTH is strongly recommended in patients with HPT selected for MIRS to confirm complete removal of hyperfunctioning parathyroid tissue; (4) MIRS can be useful also in patients with HPT who previously received parathyroid/thyroid surgery with the aim of limiting surgical trauma at reoperation and minimizing the related risk of complications; (5) with the exception of PA located in ectopic sites, IGP does not seem to be a recommendable technique in patients with HPT concomitant nodular goiter
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
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