1,720,970 research outputs found
Radiation Exposure in Biliary Procedures Performed to Manage Anastomotic Strictures in Pediatric Liver Transplant Recipients: Comparison Between Radiation Exposure Levels Using an Image Intensifier and a Flat-Panel Detector-Based System
No full textThe aim of this study was to estimate radiation exposure in pediatric liver transplants recipients who underwent biliary interventional procedures and to compare radiation exposure levels between biliary interventional procedures performed using an image intensifier-based angiographic system (IIDS) and a flat panel detector-based interventional system (FPDS
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
Diagnosis of sclerosing cholangitis in children: Blinded, comparative study of magnetic resonance versus endoscopic cholangiography
No full textBACKGROUND:Magnetic resonance cholangiography (MRC) has been validated as comparable to endoscopic retrograde cholangiography (ERC) for the diagnosis of sclerosing cholangitis (SC) in adult patients. In children, MRC is widely used based mainly on non-comparative studies.
PATIENTS AND METHODS: ERCs and MRCs of seven children (median age 9, range: 7-20 years) with SC and 17 controls (median age 6, range: 2months-20years) with other chronic liver diseases were reviewed in a blinded, random and independent way. All patients underwent both examinations within a 6-months slot. All ERCs and 17 MRCs were performed under general anesthesia. One radiologist evaluated both ERCs and MRCs and one interventional endoscopist independently reviewed only ERCs. Reviewers did not receive any clinical information. Diagnosis of SC, established on the basis of history, laboratory data, radiological examinations and clinical course, was used as gold standard to compare ERC and MRC diagnostic accuracy.
RESULTS:
Overall image quality was graded as very good in 57% of MRC and in 71% of ERC cases; difference was not statistically significant (P=0.24) although the probability for MRC to be diagnostic increased with patient's age. Depiction of first, second and fourth-order intrahepatic bile duct was better in ERC (P=0.004, 0.02 and 0.023, respectively); depiction of the extrahepatic bile duct was comparable (P=0.052). Diagnostic accuracy of MRC and ERC was very high, without statistically significant difference (P=0.61).
CONCLUSION: Despite an overall better depiction of the biliary tree by ERC, MRC is comparable for the diagnosis of SC in children. These data support MRC as the first imaging approach in children with suspected SC
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
Measurement of hepatic vein pressure gradient in children with chronic liver diseases
No full textThe aim of this study is to present our preliminary experience with Hepatic Vein Pressure Gradient (HVPG) measurements in pediatric patients with chronic liver disease.
HVPG was measured in 20 pediatric patients, mean age 82+/-54 months, with chronic liver disease, without extrahepatic portal vein obstruction. In nine patients the end-stage liver disease was secondary to biliary atresia; in the remaining 11, to various causes. Eleven patients had esophageal varices at endoscopy, 14 had perigastric and periesophageal collaterals at imaging scan, three had ascites, 12 had low platelet count, and all had splenomegaly.
Hepatic vein catheterization was technically possible in all patients without complications. HVPG values were elevated in all but three patients, ranging between 2 and 33 mmHg (mean 11.3+/-7.2 mmHg), thus indicating a sinusoidal component in portal hypertension. A salient finding was the presence of hepatic venovenous shunts in 7 out of 9 patients with biliary atresia; however, the HVPG could still be measured distal to the shunts, but in three patients (with an HVPG of 8 mmHg) it was determined in an area with a small venovenous communication still visible, therefore underestimating the actual portal pressure gradient. No venovenous shunts were detected in the non-biliary atresia patients.
In conclusion, HVPG is a feasible procedure in pediatric patients. Patients with biliary atresia very frequently have communicating vessels between hepatic veins. This hitherto unacknowledged finding can lead to the underestimation of portal pressure by HVPG measurement
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