1,721,231 research outputs found
Affinity of ucb 30889 for rat recombinant SV2A (wildtype and mutants) labeled with [<sup>3</sup>H]ucb 30889 (n = 3).
No full text<p>Affinity of ucb 30889 for rat recombinant SV2A (wildtype and mutants) labeled with [<sup>3</sup>H]ucb 30889 (n = 3).</p
(A) Change in RMSDs from 80 ns of the Inward-ucb 30889 simulation (green) and (B) the Outward-ucb 30889 simulation (red lines) from the initial snapshot from the respective apo simulations
No full text<p>. Helix conservation in the (C) Inward-ucb 30889 and (D) Outward-ucb 30889 simulations.</p
Binding characteristics of [3H]ucb 30889 to levetiracetam binding sites in rat brain.
No full textLevetiracetam (2S-(2-oxo-1-pyrrolidinyl)butanamide, KEPPRA, a novel antiepileptic drug, has been shown to bind to a specific binding site located in brain (levetiracetam binding site [Eur. J. Pharmacol. 286 (1995) 137]). However, [3H]levetiracetam displayed only micromolar affinity for these sites making it an unsuitable probe for further characterization. The present study describes the binding properties of an analogue of levetiracetam: [3H]ucb 30889, (2S)-2-[4-(3-azidophenyl)-2-oxopyrrolidin-1-yl]butanamide. [3H]ucb 30889 binds reversibly to specific binding sites in rat brain. Kinetics at 4 degrees C were biphasic with half-times of association and dissociation of, respectively, 3 and 4 min for the fast component and 47 and 61 min for the slow component. [3H]ucb 30889 saturation binding curves were compatible with the labelling of a homogenous population of binding sites having a B(max) of 4496+/-790 fmol/mg protein (mean+/-S.D. n=5) and a K(d) of 62+/-20 nM (mean+/-S.D. n=5), a 20-fold increase in affinity compared to [3H]levetiracetam. Competition binding curves with ligands known to interact with levetiracetam binding sites and tissue distribution restricted to the brain indicated that [3H]ucb 30889 and [3H]levetiracetam bind to the same site. Although levetiracetam binding sites and GABA(A) (gamma-aminobutyric acid) receptors share some ligands such as pentobarbital and pentylenetetrazol, experiments performed with [35S]TBPS (tert-butyl-bicyclo[2.2.2]phosporothionate), a probe for the GABA(A) Cl(-) channel do not support the hypothesis that levetiracetam binding sites are part of the GABA(A) receptor complex. Preliminary autoradiography studies in rat brain revealed that [3H]ucb 30889 labels specific sites in all brain regions and that this binding is concentration-dependently displaced by levetiracetam.Comparative StudyJournal ArticleSCOPUS: ar.jinfo:eu-repo/semantics/publishe
Characterization of [(3)H]ucb 30889 binding to synaptic vesicle protein 2A in the rat spinal cord.
No full textThe novel antiepileptic drug levetiracetam ((2S-(2-oxo-1-pyrrolidinyl)butanamide, KEPPRA possesses a specific binding site in brain, which has very recently been identified as the synaptic vesicle protein SV 2 A. The aim of this study was to evaluate the presence of a levetiracetam binding site in the spinal cord and compare its properties to that in rat brain. We used [(3)H]ucb 30889 ((2S)-2-[4-(3-azidophenyl)-2-oxopyrrolidin-1-yl]butanamide), a levetiracetam analogue, to perform binding assays, photoaffinity labelling and autoradiography experiments, and revealed the presence of SV 2 A by Western-blot analysis. [(3)H]ucb 30889 binding kinetics at 4 degrees C were biphasic and saturation binding curves were compatible with the labelling of a homogenous population of binding sites with a K(d) similar to that in brain. Competition curves with ligands known to interact with levetiracetam binding sites and photolabelling experiments indicated that [(3)H]ucb 30889 labels the same 90 kDa protein in both spinal cord and brain. Levetiracetam binding site was localised in the grey matter of the spinal cord and its expression was not modified in a model of neuropathic pain. This study demonstrates the presence of a specific levetiracetam binding site in the rat spinal cord, which is similar to that found in rat brain.Comparative StudyJournal ArticleSCOPUS: ar.jinfo:eu-repo/semantics/publishe
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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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