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Behavior of the potential antitumor VIVO complexes formed by flavonoid ligands. 1. Coordination modes and geometry in solution and at the physiological pH
No full textThe coordination modes and geometry assumed in solution by the potent antitumor oxidovanadium(IV) complexes formed by different flavonoids were studied by spectroscopic (Electron Paramagnetic Resonance, EPR) and computational (Density Functional Theory, DFT) methods. A series of bidentate flavonoid ligands (L) with increasing structural complexity was examined, which can involve (CO, O−) donors and formation of five- and six-membered chelate rings, or (O−, O−) donors and five-membered chelate rings. The geometry corresponding to these coordination modes can be penta-coordinated, [VOL2], or cis-octahedral, cis-[VOL2(H2O)]. The results show that, at physiological pH, ligands provided with (CO, O−) donor set yield cis-octahedral species with “maltol-like” coordination when five-membered chelate rings are formed (as with 3-hydroxyflavone), while penta-coordinated structures with “acetylacetone-like” coordination are preferred when the chelate rings are six-membered (as with chrysin). When both the binding modes are possible, as with morin, the “acetylacetone-like” coordination is observed. For the ligands containing a catecholic donor set, such as 7,8-dihydroxyflavone, baicalein, fisetin, quercetin and rutin, the formation of square pyramidal complexes with (O−, O−) “catechol-like” coordination and five-membered chelate rings is preferred at physiological pH. The determination of the different coordination modes and geometry is important to define the biotransformation in the blood and the interaction of these complexes with the biological membranes
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
Potentiometric and spectroscopic studies in the coordination ability of copper (II) to 2-(2'-3'-dideoxy-beta-D-erythro-2-hexenepyranosyl)-2-amino propionic acid
No full textSpectroscopic studies on the binding of iron(II) and (III) ions to polygalacturonic acid
No full textIndagine esplorativa sulla qualità ambientale dei più importanti acquiferi del Taloro
No full textL’obiettivo principale di questa ricerca è la
determinazione dell’eventuale stato di inquinamento
dei più importanti acquiferi del Taloro mediante
l’analisi di parametri chimici di base, dei metalli e dei
microinquinanti organici. La formulazione del
giudizio della qualità delle acque è stata effettuata
attraverso i parametri indicati nel Decreto Legislativo
152/99, allegato 1, punti 3.2.The main aim of this research is to point out the
pollution status of the most important watercourses
of Taloro through the analysis of chemical
parameters, metals and organic micro-pollutants of
environmental and toxicological interest. The
evaluation of the quality of waters was made using
the parameters reported in the DLgs. 152/99,
enclosure 1, point 3.2
Birmingham Hip Resurfacing: A Minimum Follow Up Of Ten Years. Results From An Independent Centre
No full text
COORDINATION OF METAL-IONS BY INDOLIC ACIDS - COPPER(II) COMPLEXES OF INDOLE-3-CARBOXYLIC, INDOLE-5-CARBOXYLIC, INDOLE-N-ACETIC, AND N-METHYLINDOLE-2-CARBOXYLIC ACIDS
No full textVariations 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
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