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4,6,4’-Trimethylthioangelicin, a new furocoumarin derivative with potential photochemotherapeutic proprieties.
No full text
Activity of 3-Carbethoxyangelicin Photolysis Products
No full text3-Carbethoxyangelicin (3-CA), carrying an electron-withdrawing group at the pyrone side, has been prepared to have a fully monofunctional
angelicin derivative. 3-CA does not photoreact with DNA and induces a moderate antiproliferative activity. 3-CA proved to be extremely
sensitive to ultraviolet A (UVA) light, undergoing rapid photolysis. Only one photolysis product has been isolated and identified. By means
of alkaline elution, we observed that 3-CA and its photolysis products are able to induce a large amount of single-strand breaks in DNA in
vivo. The results obtained from studying the capacity to produce singlet oxygen suggest that the photodynamic mechanism of action of 3-CA
very likely results from its capacity--as well as that of its photolysis products--to produce singlet oxygen
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
Farmaco per la cura della talassemia, anemia falciforme e di tutte le forme di anemia trattabili con questo farmaco, costituito da una miscela di prodotti di fotodegradazione di furocumarine, composizione farmaceutica avente come primcipio attivo il farmaco
No full textIl brevetto descrive un’applicazione del trattamento delle cellule eritroidi da sangue periferico con UVA e psoraleni. Abbiamo dimostrato che il trattamento combinato ha un effetto molto importante nell’indurre il differenziamento e l’incremento di produzione di emoglobina fetale (HbF). Pertanto, questi risultati ci permettono di ipotizzare un utilizzo di questo protocollo per la terapia della talassemi
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
In vitro phototoxic properties of triamcinolone 16,17-acetonide and its main photoproducts
Full text linkThe phototoxicity of triamcinolone 16,17-acetonide has been estimated through a panel of in vitro tests. The main target involved in phototoxicity induced by triamcinolone appeared to be the cell membrane. Oxygen-independent photohemolysis was observed. A photochemical study in water and buffered solutions supported the conclusion that this is related to the action of radicals formed upon UV irradiation (in particular UV-B) by Norrish Type-I fragmentation of the C-20 ketone group. Peroxy radicals were formed in the presence of oxygen and were the active species in that case. Three photoproducts, isolated from the photodegradation of the drug, were submitted to the same toxicity tests. Two of them were proved to possess toxic or phototoxic properties on erythrocytes, primarily induced by UV-B light, and may participate in the photosensitizing activity of triamcinolone 16,17-acetonide. Our in vitro results suggest that the drug can elicit weak photosensitizing properties in vivo
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