1,720,955 research outputs found
“NOVEL METALLACYCLIC SYSTEMS OF Ru(II) AS POTENTIAL ANTICANCER DERIVATIVES: CHEMISTRY AND BIOACTIVITY”
No full textMany Ru(II) complexes are considered valid candidates as anticancer drugs since they show reduced cytotoxicity and genotoxicity in non-tumor cells. In addition, these compounds present lower chances of cancer cells developing intrinsic or acquired resistance due to their peculiar paths of action. Many cytotoxic metal complexes of Ru(II) with NSAIDs (as ibuprofen, naproxen or acetylsalicylic acid) have been reported as effective antitumor agents. Furthermore, we are convinced that the incorporation of a gold atom into the Ru(II) metal skeleton may induce cooperative features, potentially enhancing anticancer properties.
Complexation studies of [Ru(H)2(CO)(PPh3)3] with several ligands such as amino acid derivates as 5-hydroxy-L-triptophane or NSAIDs as ibuprofen or thiosalicylic acid (TSA), and its corresponding gold(I) complex [Au(TSA)(PPh3)], have been carried out with the aim to investigate the antitumor properties in addition to the potential increased bioactivity added by gold coordination. The ligands bearing oxygen or nitrogen donor heteroatoms are coordinated to the Ru(II) center through O,O- or N,O- bidentate fashion modes.
The resulting complexes have been studied by analytical and spectroscopic techniques (ESI-MS, IR and heteronuclear bidimensional NMR) and their cytotoxic activities have been evaluated towards cancer cells
Synthesis and Biological Investigations on Ruthenium Complexes Bearing Pyrrole Derivatives
No full textA series of Ruthenium compounds, which contain pyrrole 2-carboxylic acid (HL1) or 2-pyrrole carboxaldehyde (HL2), have been selectively synthesized. The reaction between [Ru(H)2(CO)(PPh3)3], 1, and HL1 results in the formation of homoleptic k2(O,O)-[Ru(H)(CO)L2(PPh3)2], 2. Thus under prolonged CH3CN refluxing treatment, compound 2 undergoes a transformation, leading to the stable neutral solvento-pyrrolide species k2(N,O)-[Ru(CH3CN)(CO)(L1))(PPh3)2], 3. This transformation promotes an unusual conversion from O,O- to N,O- chelate fashion mode. On the other hand, the reaction between 1 and HL2 yields two distinct diastereoisomers of the type k2(N,O)-[Ru(H)(CO)L2(PPh3)2], namely 4 and 5. However, by optimizing the experimental conditions, both compounds 4 and 5 have been selectively obtained. The structures of the pyrrolyl-derivatives have been characterized using single crystal X-ray diffraction, and their purity has been assessed from ESI-MS, NMR and IR analyses. Promising biological activities have been investigated for complexes by antibacterial tests, conducted on Gram-positive and Gram-negative bacteria. Further, detailed information concerning anticancer properties of the complexes have been inferred through antiproliferative tests on human cancer cell lines
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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