1,721,342 research outputs found
An Analytical Model of a Circular rotating basin under the effect of periodic wind forcing
No full textReduction of HDL- and LDL-associated cholesterylester and phospholipid hydroperoxides by phospholipid hydroperoxide glutathione peroxidase and Ebselen (PZ 51).
No full textOxidation of 3-hydroxyanthranilic acid to the phenoxazinone cinnabarinic acid by peroxyl radicals and by compound I of peroxidases or catalase
No full textSince 3-hydroxyanthranilic acid (3HAA), an oxidation product of tryptophan metabolism, is a powerful radical scavenger [Christen, S., Peterhans, E., ; Stocker, R. (1990) Proc. Natl. Acad. Sci. U.S.A. 87, 2506], its reaction with peroxyl radicals was investigated further. Exposure to aqueous peroxyl radicals generated at constant rate under air from the thermolabile radical initiator 2,2'-azobis[2-amid-inopropane] hydrochloride (AAPH) resulted in rapid consumption of 3HAA with initial accumulation of its cyclic dimer, cinnabarinic acid (CA). The initial rate of formation of the phenoxazinone CA accounted for approximately 75% of the initial rate of oxidation of 3HAA, taking into account that 2 mol of 3HAA are required to form 1 mol of CA. Consumption of 3HAA under anaerobic conditions (where alkyl radicals are produced from AAPH) was considerably slower and did not result in detectable formation of CA. Addition of superoxide dismutase enhanced autoxidation of 3HAA as well as the initial rates of peroxyl radical-induced oxidation of 3HAA and formation of CA by approximately 40-50%, whereas inclusion of xanthine/xanthine oxidase decreased the rate of oxidation of 3HAA by approximately 50% and inhibited formation of CA almost completely, suggesting that superoxide anion radical (O2.-) was formed and reacted with reaction intermediate(s) to curtail formation of CA. Formation of CA was also observed when 3HAA was added to performed compound I of horseradish peroxidase (HRPO) or catalytic amounts of either HRPO, myeloperoxidase, or bovine liver catalase together with glucose/glucose oxidase.(ABSTRACT TRUNCATED AT 250 WORDS
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
MODULATION OF CELLULAR CHOLESTEROL EFFLUX PATHWAYS BY DIFFERENT PROBUCOL-LIKE ANALOGUES
No full textProbucol is a phenolic lipid lowering agent, able to reduce atherosclerosis and restenosis following percutaneous coronary angioplasty in vivo model. In vitro probucol is an effective inhibitor of ABCA1-mediated cholesterol efflux. This effect may in part explain the reported in vivo HDL-lowering action of probucol. The aim of this study was to compare the activity of probucol and its analogues, the monosuccinate ester (AGI-1067), the probucol dithio-bisphenol (DTBP) and its monosuccinate (DTBPs), in modulating cholesterol efflux process trough the different pathways. To this aim cells were labeled with [3H]-cholesterol. Cells were then equilibrated in 0.2% BSA-containing medium and subsequently treated with probucol or its analogues. Cholesterol efflux to the different acceptors, was measured by the release of [3H]-cholesterol into the medium. None of the tested compounds had effect on either passive diffusion of cholesterol in MPM or on SRBI-mediated cholesterol efflux in Fu5AH rat hepatoma cells. The ABCA1-mediated efflux was measured in MPM stimulated with LXR-RXR agonists. The results showed AGI-1067 to be a stronger inhibitor of ABCA1-mediated efflux compared to probucol and DTBPs. The analogue DTBP had not any effect on efflux via ABCA1. AGI-1067 and DTBPs but not probucol and DTBP, were able to inhibit efflux of cholesterol in CHO cells over-expressing hABCG1 by about 50%. In conclusion the presence of a dithio ketal group on both probucol and probucol-like analogues may be required for the inhibition of ABCA1 cholesterol efflux. The esterification of one of the phenolic group of probucol may enhance the inhibitory effect of the ABCA1 pathway. In addition the presence of the esterified ossydrylic group may be required for the interaction of the molecule with the ABCG1 transporter. Identifying probucol-like analogues may help to explore the mechanism and function of ABCA1-, ABCG1- and SR-BI-mediated cholesterol efflux and their potential therapeutic role
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
EFFECT OF PROBUCOL DERIVATE SUCCINOBUCOL (AGI-1067) ON CELLULAR CHOLESTEROL EFFLUX PATHWAYS
No full textAppropriate 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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