1,721,018 research outputs found
Role of narrow-band imaging in detection of head and neck unknown primary squamous cell carcinoma
No full textObjectives/Hypothesis: There is no general consensus on what kind of examination to include in an optimal detection strategy for head and neck squamous cell carcinomas of unknown primary (SCCUPs). This study investigates the role of narrow-band imaging (NBI) in their identification.Study Design: Case series.Methods: Twenty-nine consecutive patients affected by SCCUPs were referred at two academic institutions. Selection criteria were: 1) lymph node cytology positive for squamous cell carcinoma (SCC); 2) no evidence of any primary at white light (WL); 3) negative contrast-enhanced computed tomography (CT) and/or magnetic resonance imaging, and positron emission tomography-CT; and 4) no contraindication to general anesthesia. Each patient underwent office-based NBI panendoscopy. If a suspicious area was identified, a biopsy was performed for histological confirmation. When no suspicious area was detected in the office, patients underwent WL and NBI under general anesthesia. If this examination was still negative, bilateral tonsillectomy and base of the tongue (BOT) mucosectomy were performed.Results: Office-based NBI identified 10 SCCs (34.5%), one in the nasopharynx, three in the tonsil, four in the BOT, and two in the supraglottis. In only one (3.5%) NBI-negative patient was a primary found in the BOT. In one (3.5%) we found an NBI suspicious area during panendoscopy under general anesthesia, but histology did not confirm this finding after BOT mucosectomy. Seventeen (58.6%) patients remained as having true SCCUPs. NBI sensitivity, specificity, positive, negative predictive values, and accuracy were 91%, 95%, 91%, 95%, and 90%, respectively.Conclusions: In the present study, office-based NBI increased the detection rate of head and neck SCCUPs by 34.5% and should be strongly recommended as an adjunctive tool in their diagnostic workup
Microsurgical procedures during COVID‐19 pandemic: the VITOM® 3D‐HD exoscopic system as alternative to the operating microscope to properly use personal protective equipment (PPE)
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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
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
Endoscopic Preoperative Assessment, Classification of Stenosis, Decision-Making
No full textPediatric Laryngo-Tracheal Stenosis (LTS) comprises different conditions that require precise preoperative assessment and classification. According to the guidelines, the optimal diagnostic work-up of LTS patients relies both on a comprehensive anamnesis and on endoscopic and radiological assessments. All the causes of LTS result in an impairment in airflow, mucociliary clearance, phonation, and sometimes in swallowing disorders. The main goals of treatment are to maintain an adequate respiratory space and restore the Upper Aero-Digestive Tract (UADT) physiology. The first step when dealing with LTS patients is to properly assess their medical history. The main causes of pediatric LTS can be divided into two groups, i.e., congenital and acquired. The most common causes of congenital LTS are: laryngomalacia (60%), vocal fold paralysis (15–20%), subglottic stenosis (SGS) (10–15%), laryngeal webs and atresia (5%), subglottic hemangioma (1.5–3%), and others. On the other hand, 90% of acquired pediatric LTS cases are subsequent to post-intubation injuries. Other less frequent causes are: iatrogenic complications from endoscopic laryngeal interventions, benign tumors, caustic or thermal injuries, external blunt force injury or trauma, chronic inflammatory disorders, or idiopathic causes. Diagnostic work-up consists in a step-by-step investigation: awake and asleep transnasal fiberoptic laryngoscopy (TNFL), direct laryngoscopy with 0° and angled telescopes to investigate the type of stenosis (arytenoid mobility, craniocaudal extension, involved anatomical sites, and active or mature scar tissue), and broncho-esophagoscopy to rule out associated mediastinal malformations. To date there are several available classifications for each of the involved sites: Cohen's classification for anterior glottic stenosis, Bogdasarian's for posterior glottic stenosis (PGS) and Myer-Cotton's for subglottic stenosis, even though others are used in daily practice (Lano-Netterville, FLECS, etc.). The European Laryngological Society recently proposed a new classification which is applicable in all LTS cases. In this chapter we deal with preoperative assessment and staging, reviewing the most relevant classifications applicable in patients affected by LTS, conditio sine qua non in order to tailor the best treatment modality to each subject. We'll also detail the comprehensive radiological, endoscopic and functional assessment for the correct use of each staging classification
D1 versus D2 pancreatoduodenectomy in surgical therapy of pancreatic head cancer.
No full textBACKGROUND/AIMS - The aim of this study was to evaluate the influence of standard pancreatoduodenectomy versus pancreatoduodenectomy with extended lymphadenectomy and the role of adjuvant therapy on survival in patients with ductal adenocarcinoma of the pancreatic head. In addition the problems related to resection are discussed.
METHODOLOGY - A total number of 124 pts operated on between 1985 and 1999 were divided into three groups according to our different strategies. Standard resection (D1) was performed on 48 patients (group A), extended resection (D2) on 45 patients (group B) and combined treatment (extended resection plus adjuvant therapy) on 31 patients. The outcome of these three groups was compared with regard to postoperative morbidity and survival.
RESULTS - There was no significant difference in terms of survival between group A and B, while adjuvant therapy (group C), achieved statistical significance as factor influencing survival, together with tumor stage.
CONCLUSIONS - Our data suggest that no further improvement can be obtained on long-term survival by extended retroperitoneal dissection while chemoradiotherapy showed a doubling of median survival
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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