1,720,982 research outputs found
Antiproliferative and Cytotoxic Effects on Malignant Melanoma Cells of Essential Oils from the Aerial Parts of Genista sessilifolia and G. tinctoria
No full textGenista species (family Leguminosae) show interesting biological properties. In this paper we describe the biological activity of the essential oils extracted from the aerial parts of G. sessilifolia DC. and G. tinctoria L. against M14 human melanoma cells, testing several biochemical parameters, such as cell vitality, cell membrane integrity and genomic DNA fragmentation. In addition, we report for the first time the study of the composition of the essential oil obtained from G. tinctoria. The most abundant components of the oil were carbonylic compounds such as (E)-β-ionone (9.1%), dihydroactinidiolide (7.3%), nonanal (5.1%) and hexahydrofarnesylacetone (4.3%). The essential oils from aerial parts of both G. sessilifolia and G. tinctoria showed interesting potential anticancer activity, suggesting the presence of active compounds
Effect of propolis on human cartilage and chondrocytes.
No full textPropolis, a natural product derived from plant resins collected by the honeybees, has been used for thousands of years in folk medicine for several purposes. The extract that contains amino acids, phenolic acids, phenolic acid esters, flavonoids, cinnamic acid, terpenes and caffeic acid, possesses several biological activities such as anti-inflammatory, immunostimulatory, anti-viral and anti-bacterial. In this study, we assay the effects of propolis extract on the production of key molecules released during chronic inflammatory events as nitric oxide (NO) and glycosaminoglycans (GAGs) in cultures of human cartilaginous tissues and chondrocytes, stimulated with interleukin-1beta (IL-1beta). We observed that this natural compound and its active principle, caffeic acid phenethyl ester (CAPE), were able to contrast the harmful effects of IL-1beta. Our data clearly demonstrated the protective action of propolis in cartilage alteration, that appears greater than that elicited by indomethacin, commonly employed in joint diseases
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
Increased tumor cell multiplication after radiofrequency lesions in median hypothalamus in the mouse and rat
No full textA significant increase of cell multiplication in inoculated ascitic and solid tumors was demonstrated in both DBA/2 and C57BL/6 mice as well as in Wistar rats after radiofrequency lesions in the median hypothalamus (ventromedial and dorsomedial nuclei; part of arcuate nucleus). The following tests were performed: Mitotic and metaphasic index, doubling time of tumor, incorporation of tritiated thymidine into DNA, cell cycle parameters and growth fraction. The increased rate of cell proliferation measured was predominantly due to the higher speed of DNA biosynthesis with a minor contribution by an increase of the growth fraction. In the animals with hypothalamic lesions we demonstrated a slight decrease in the secretory activity of the adenohypophysis. Because it is generally stated that failure of hypophysis function hinders cell multiplication in normal and neoplastic tissues, we think that heightened cell proliferation after hypothalamic lesions is due to suppression of an inhibitory mechanism located in the hypothalamus and which is independent of the hypophysis
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