1,720,954 research outputs found
3D MR vs conventional X-ray hysterosalpingography in the evaluation of female infertility
No full textPurpose: Aim of this work was to compare the new 3D MR-histerosalpingography with the X-ray conventional one in the evaluation of female infertility.
Method and materials: 15 infertile female patients (aging 29 - 43 years, mean 35) were studied with a 1.5 T magnet unit (GE Horizon 8.5) using a T2 weighted FSE sequences on axial and coronal plane and a 3D Fast SPGR sequence (3D MRA sequence) on coronal plane after injection of a diluted gadolinium solution into the uterine cavity via a balloon catheter. All the data were compared with conventional X-ray hysterosalpingography.
Results: The tomographic images provided a complete evaluation of the uterus and ovaries. The 3D MR technique provided the evidence of the uterine cavity and the patency of the Fallopian tube with a complete concordance with X ray histerosalpingography. However the accuracy in detecting the Fallopian tube calibre was considered inferior with MRI than X-ray by two expert radiologists. Two Fallopian tube stenosis were missed at 3D MR-histerosalpingography.
Conclusion: 3D MR histerosalpingography may represent a real promising technique in the non-invasive evaluation of the infertile female. The main advantage is related to the lack of ionising radiation in these young females. Up to date, in our experience, the MR technique does not have the same accuracy as X-ray in detecting the Fallopian tube. Improvement in spatial resolution probably have to be considered
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
Volume rendered 3D reconstruction of MRA images vs MRA MIP reconstruction in the evaluation of aortic dissection
No full textPurpose: To evaluate the potential advantages of the volume rendering (VR) 3D algorithm vs maximum intensity projection (MIP) reconstruction in the MR evaluation of aortic dissection.
Materials and Methods: Thirty-four patients affected by aortic dissection underwent MRA evaluation employing a 1.5 T superconductive magnet (GE Signa Horizon 8.3) with phased-array coil. The examination was performed using a 3D SPGR sequence acquired during automatic injection of 0.2 mmol/kg of Gd-BOPTA. Images were double-blindly reviewed by two radiologists after MIP and VR reconstruction algorithm. Evidence of intimal flap, aortic branch involvement and extension of the aortic dissection were analyzed. Interobserver agreement was obtained after source image evaluation.
Results: Both algorithms required at least 3 min of post-processing. VR reconstruction provided better 3D effects compared with MIP reconstruction, with more precise detection of the intimal flap (VR x/34 p= x; MIP x/34 p=x) and its aortic extension (VR x/34 p= x; MIP x/34 p=x). Aortic branch involvement was better seen on VR reconstructions (VR x/34 p= x; MIP x/34 p=x).
Conclusion: VR reconstruction is an efficient technique for generation of 3D images from MR data set. It provides a better comprehension of the intimal flap, especially when there is an involvement of tortuous vessels, in comparison with MIP reconstruction
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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