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Ruthenium polypyridyl complexes and their modes of interaction with DNA : is there a correlation between these interactions and the antitumor activity of the compounds?
Get PDFVarious interaction modes between a group of six ruthenium polypyridyl complexes and DNA have been studied using a number of spectroscopic techniques. Five mononuclear species were selected with formula [Ru(tpy) L1L2](2-n)?, and one closely related dinuclear cation of formula [{Ru(apy)(tpy)}2{l-H2N(CH2)6NH2}]4?. The ligand tpy is 2,20:60,200-terpyridine and the ligand L1 is a bidentate ligand, namely, apy (2,20-azobispyridine), 2-phenylazopyridine, or 2-phenylpyridinylmethylene amine. The ligand L2 is a labile monodentate ligand, being Cl-, H2O, or CH3CN. All six species containing a labile L2 were found to be able to coordinate to the DNA model base 9-ethylguanine by 1H NMR and mass spectrometry. The dinuclear cationic species, which has no positions available for coordination to a DNA base, was studied for comparison purposes. The interactions between a selection of four representative complexes and calf-thymus DNA were studied by circular and linear dichroism. To explore a possible relation between DNA-binding ability and toxicity, all compounds were screened for anticancer activity in a variety of cancer cell lines, showing in some cases an activity which is comparable to that of cisplatin. Comparison of the details of the compound structures, their DNA binding, and their toxicity allows the exploration of structure–activity relationships that might be used to guide optimization of the activity of agents of this class of compounds
Synthesis, characterization and tumor cell growth inhibition of new transplatinum complexes with phosphane derivatives
No full textWe have reported the synthesis and characterization of two new trans platinum complexes in the phosphane series, where the phosphane ligand is triphenylphosphine [P(Ph)3] and the group in the trans configuration is represented by chiral aliphatic amines, (racemic in complex 1 and S–NH2CH2CH(CH3)CH2CH3 in complex 2). The anti-proliferative activity detected in tumor cells treated with the two new complexes is more pronounced when the aliphatic amine is racemic compared to the S-enantiomer. Moreover, for both compounds, the activity is fast after cell exposure and, unlike that of cisplatin, virtually independent of the duration of cell challenge
Cytotoxic Profile and Peculiar Reactivity with Biomolecules of a Novel "Rule-Breaker" Iodidoplatinum(II) Complex
No full textSolution Behaviour and Biomolecular Interactions of Two Cytotoxic trans-Platinum(II) Complexes Bearing Aliphatic Amine Ligands
No full textReactivity and Biological Properties of a Series of Cytotoxic PtI(2)(amine)(2) Complexes, Either cis or trans Configured
No full textDifferences Between Asymmetric cis and trans Platinum Complexes. Applications in Cancer Chemotherapy
Get PDFThis thesis describes a variety of asymmetric cis- and trans-platinum(II) complexes. The major aim of this research has been the design of complexes with high antitumor activity that may overcome cisplatin resistance, and to establish a comparison between complexes with both geometries. These new type of asymmetric platinum complexes contain in all cases the iPram ligand and in addition either aliphatic amines or azole ligands. Furthermore, a strong emphasis on asymmetric trans-Pt(II) complexes with azole ligands is presented in this research.Kreatech, NWOUBL - phd migration 201
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
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