1,720,962 research outputs found
Short-term activation by low 17beta-estradiol concentrations of the Na+/H+ exchanger in rat aortic smooth muscle cells: physiopathological implications
No full textLipophilic beta-adrenoceptor antagonists stimulate low density lipoprotein receptor activity in human skin fibroblasts.
No full textGastric antisecretory, antiulcer and cytoprotective properties of 9-hydroxy-19,20-bis-nor-prostanoic acid in experimental animals
No full text9-Hydroxy-19,20-bis-nor-prostanoic acid (IBI-C83) was evaluated on gastric acid secretion and gastric lesions induced in laboratory animals by a variety of experimental conditions: compound IBI-C83 is proved effecttive in decreasing basal, histamine- and pentagastrin-stimulated total acid output in rats and in pentagastrin perfused dogs. The concentration of N-acetylneuraminic acid in the gastric fluid, a marker of mucus secretion, is enhanced in rats by IBI-C83. This drug prevents gastric damage induced by non-steroidal antiinflammatory compounds such as acetylsalicylic acid, indometacin and phenylbutazone, gastric ulcers following pylorus ligation, and facilitates healing of the gastric ulcers evoked by subserosal injection of acetic acid. A prominent feature of IBI-C83 is its capacity to protect the rat from gastric damage elicited by necrotizing agents such as absolute ethanol, hydrochloric acid and hypertonic saline. This property, called 'cytoprotection' and common to naturally occurring prostaglandins, is independent on the antisecretory activity of IBI-C83 and is not shared, at least in the reported experimental models, by the H2-receptor antagonist cimetidine. In spite of the prostaglandin-like properties displayed in its cytoprotective activity, compound IBI-C83 does not affect cardiovascular functions, gastrointestinal transit and uterine motility
On the growth of cultured bovine aortic endothelial cells. Preliminary observations of ultrastructural (freeze-etching) morphology and quantitation of growth speed at phase-contrast microscopic examination: Effect of glycosaminoglycans (GAGs) [Sull' accrescimento in coltura di cellule endoteliali di aorta bovina. Osservazioni preliminari di morfologia ultrastrutturale al crio-decappaggio e quantizzazione della velocita' di crescita in microscopia a contrasto di fase: effetto di glicosaminoglicani]
No full textBovine aortic endothelial cells (BAEC), detached from thoracic aorta by collagenase treatment, have been studied after adding a mixture of glycosaminoglycans (GAGs) (the composition of which has been studied by Casu et al. -6), at different concentrations. GAGs at the concentration of 90 mg/100 ml of medium (Dulbecco's modification of Eagle's MEM with 10% foetal calf serum) produced an increase in the growth speed. We have quantitized these data both by counting the number of cells 24 h after trypsinization in phase-contrast-microscopy, and by measuring the time necessary to reach a certain number of influences. Ultrastructural observation at transmission electron microscope after freeze-etching preparation, didn't show any relevant modification either in the organization of cell membrane or in the cytoplasmatic structures. An increase of "vesicular openings" ("pits") on the plasma-membrane was evident
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
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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