1,720,974 research outputs found
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
Lipid composition in atheromatous plaque: evaluation of the lipid three-phase percentage
No full textThere is a renewed interest in the study of plaque lipid composition because it is recognized that it, rather than the luminal narrowing, influences the plaque stability and determines patient symptoms. At this purpose, we quantitatively evaluated in the carotid plaque of different categories of patients the expression of triglycerides, phospholipids, cholesterol, free cholesterol, esters of cholesterol, and the percentages of the three-phases (cholesterol, esters of cholesterol, phospholipids) by using the "Roozeboom triangle". Significant differences in the content of specific lipid and the percentage of the three-phases were detected among the different types of plaque evaluated in this study. The analysis of the three-phases by "Roozeboom triangle" may open a new approach in the study of atheromatous plaque and give new information on development of the disease
Biochemical aspects of carotid artery plaque [Aspetti biochimici della placca ateromatosa carotidea]
No full textBackground. The purpose of this study was to examine and quantify a series of biochemical parameters (proteins, nucleic acids, hypoxanthine, xanthine, uric acid, allantoin, free radicals, electrolytes, lipids and fatty acids) in carotid atheromatous plaque. Some of these substances were compared with the corresponding plasma values. Methods. Carotid artery plaque samples and plasma samples were obtained from 95 subjects (76 male, 80% and 19 female, 20%) of average age 73 years (73±5 years) subjected to carotid thromboendarteriectomy. Forty-six of these subjects were symptomatic and 49 asymptomatic. Stenosis <70% was present in 46 patients while in 49 stenosis was ≥70%. The plaque was characterised morphologically by echo color-Doppler. The methods adopted, and at times modified, for the extraction and quantitative analysis of the various biochemical parameters analysed, starting from often only small quantities of plaque, are described. Results. The results showed that plaque presents various significant differences in various metabolites that are not always related to the clinical data. Conclusions. Even though at the moment it is not possible to reach definitive conclusions, of all the substances analysed the parameters for oxidative stress and the study of nucleic acids and proteoma are the most promising and interesting fields for characterising plaque "at risk"
Purine nucleotide catabolism in rat liver labelling of uric acid and allantoin after administration of various labelled precursors.
No full textEffects of testosterone on triglycerides levels and fatty acid composition in the liver and serum of rat
No full textTriacyglycerol content and fatty acid composition has been determined in the liver and in the serum of normal, castrated and testosterone-treated rats. Most variations were found in UNS/SAT ratio, which were referred to an action of the hormone on the delta 5-delta 6-delta 9 desaturases. Results concerning the behaviour of delta 9 desaturase suggest that either different isoenzymes are involved or that a single enzyme undergoes a different regulation according to the substrate involved
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