1,721,008 research outputs found
Benzofuran hydrazones as potential scaffold in the development of multifunctional drugs: Synthesis and evaluation of antioxidant, photoprotective and antiproliferative activity
Full text linkNew benzofuranhydrazones 3–12 were easily prepared and assayed for their radical-scavenging ability. Hydrazones 3–12 showed different extent antioxidant activity in DPPH, FRAP and ORAC assays. Good antioxidant activity is related to the number and position of hydroxyl groups on the arylidene moiety. High antioxidant activity is showed by the 2-hydroxy-4-(diethylamino)benzylidene derivative 11. Furthermore, hydrazones 3–12 showed photoprotective capacities with satisfactory in vitro SPF as compared to the commercial PBSA sunscreen filter. The antiproliferative effects of the hydrazones 3–12 was tested on erythroleukemia K562 and Colo-38 melanoma human cells. All the compounds showed growth inhibition in the micromolar to sub micromolar concentration range. If taken together these results points to benzofuran hydrazones as potential multifunctional molecules especially in the treatment of neoplastic diseases being the good antioxidant properties of 5, 7 and 11 correlated to their high antiproliferative activity
Low‐Impact Synthesis of γ‐Lactones through Photoinduced Baeyer‐Villiger Oxidation of Cyclic Ketones
No full textA photocatalyzed oxidation of functionalized cyclobutanones to access -lactones has been performed in acetonitrile at room temperature, using anthraquinone derivatives as catalysts in the presence of TFA. The best condition for the reaction was studied investigating a series of substituted antraquinones and irradiating the reaction at different wavelengths under O2 environment. The scope of the reaction was studied using both 2- and 3-substituted cyclobutanones, as well as enantiopure ketones obtain full preservation of its stereochemical identity after the oxidation. The process furnishes in most cases the desired compounds with high purity after simple filtration of the catalyst, reducing the production of solvents waste
Structure-activity relationship with pyrazoline-based aromatic sulfamates as carbonic anhydrase isoforms I, II, IX and XII inhibitors: Synthesis and biological evaluation
Full text linkFour new series of aromatic sulfamates were synthesized and investigated for the inhibition of four human (h) isoforms of zinc enzyme carbonic anhydrase (CA, EC 4.2.1.1), hCA I, II, IX, and XII. The reported derivatives, obtained by a sulfamoylation reaction of the corresponding phenolic precursors, bear 3,5-diarylpyrazoline moieties as spacers between the benzenesulfamate fragment which binds the zinc ion from the active site, and the tail of the inhibitor. Pyrazolines are biologically privileged scaffolds, endowed with versatile biological activity, such as an anti-proliferative action. The derivatives were tested for the inhibition of the cytosolic, hCA I and II (off target isoforms) and the trans-membrane, tumor-associated hCA IX and XII enzymes (anticancer drug targets). Generally, hCA I was not effectively inhibited, whereas many low nanomolar inhibitors were evidenced against hCA II (KIs in the range of 0.42–90.1 nM), IX (KIs in the range of 0.72–63.6 nM), and XII (KIs in the range of 0.88–85.2 nM). The best substitution fragments at the pyrazoline ring included for CA II a 4-sulfamic group on the 3-aryl and halogens on the 5-aryl or a methoxy group on the 3-aryl and a 4-sulfamate group on the 5-aryl; for CA IX and CA XII they included the sulfamic group on the 3- or 4-position of the 5-aryl and an electronwithdrawing group on the 4-postion of the 3-aryl ring
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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