1,721,093 research outputs found
Magnetic resonance spectroscopy in epilepsy
No full textKey points \ud
• The clinical aims of MR spectroscopy (MRS) in \ud
seizure disorders are to help identify, localize \ud
and characterize epileptogeic foci. \ud
• Lateralizing MRS abnormalities in temporal lobe \ud
epilepsy (TLE) may be used clinically in combi- \ud
nation with structural and T2measurements. \ud
• Characteristic metabolite abnormalities are \ud
decreased N-acetylaspartate (NAA) with \ud
increased choline (Cho) and myoinositol (mI) \ud
(short-echo time). \ud
• Contralateral metabolite abnormalities are \ud
frequently seen in TLE, but are of uncertain \ud
significance. \ud
• In extra-temporal epilepsy, metabolite abnor- \ud
malities may be seen where MR imaging (MRI) \ud
is normal; but may not be sufficiently local- \ud
ized to be useful clinically. \ud
• MRS may help to characterize epileptogenic \ud
lesions visible on MRI (aggressive vs. indolent \ud
neoplastic, dysplasia). \ud
• Spectral editing techniques are required to \ud
evaluate specific epilepsy-relevant metabolites \ud
(e.g. -aminobutyric acid (GABA)) which may \ud
be useful in drug development and evaluation. \ud
• MRS with phosphorus (31P) and other nucleii \ud
probe metabolism of epilepsy, but are less \ud
useful clinically
Magnetisation transfer saturation (MTsat) processing
No full textMATLAB processing script and functions for MTsat and MTR parametric maps with example dataset and processed output.York, Elizabeth; Thrippleton, Michael J; Waldman, Adam. (2020). Magnetisation transfer saturation (MTsat) processing, [software]. University of Edinburgh. Centre for Clinical Brain Sciences. https://doi.org/10.7488/ds/2965
Magnetic resonance spectroscopy in seizure disorders
No full textKey points\ud
• The clinical aims of MR spectroscopy (MRS) in seizure disorders are to help identify, localize and characterize epileptogenic foci.\ud
• Lateralizing MRS abnormalities in temporal lobe epilepsy (TLE) may be used clinically in combination with structural and T2 MRI measurements together with other techniques such as EEG, PET and SPECT.\ud
• Characteristic metabolite abnormalities are decreased N-acetylaspartate (NAA) with increased choline (Cho) and myoinositol (mI) (short-echo time).\ud
• Contralateral metabolite abnormalities are frequently seen in TLE, but are of uncertain significance.\ud
• In extra-temporal epilepsy, metabolite abnormalities may be seen where MR imaging (MRI) is normal; but may not be sufficiently localized to be useful clinically.\ud
• MRS may help to characterize epileptogenic lesions visible on MRI (aggressive vs. indolent neoplastic, dysplasia).\ud
• Spectral editing techniques are required to evaluate specific epilepsy-relevant metabolites (e.g. -aminobutyric acid (GABA)), which may be useful in drug development and evaluation.\ud
• MRS with phosphorus (31P) and other nuclei probe metabolism of epilepsy, but are less useful clinically.\ud
• There is potential for assessing the of drug mode of action and efficacy through 13C carbon metabolite measurements, while changes in sodium homeostasis resulting from seizure activity may be detected with 23Na MRS.\u
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
The implications of extensive cerebral vascular dysplasia in surgical repair of coarctation of the aorta and ventricular septal defect
No full textAlthough acute neurologic problems are relatively common postoperatively in patients with arch anomalies,1 associated anomalies of the head and neck vessels are not routinely excluded preoperatively. In this report we describe the case of a patient with severe dysplasia of the intracerebral vessels and incomplete circle of Willis who underwent successful concomitant repair of a long-segment aortic coarctation and ventricular septal defect (VSD) under hypothermic circulatory arrest. Despite a satisfactory cardiovascular outcome, he had a cerebral infarction during follow-up. Modern magnetic resonance (MR) methods may assist in the diagnostic work-up of patients with arch anomalies, including coarctation. Ischemic stroke caused by cerebroarterial disease in children with congenital heart disease will also be 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
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