1,720,997 research outputs found
Fe(III)-5,10,15,20-tetrakis(pentafluorophenyl)porphine supported on pyridyl-functionalized, crosslinked poly(vinyl alcohol) as a biomimetic versatile-peroxidase-like catalyst
No full textThis paper describes the immobilization of the commercial synthetic tetrakis(pentafluorophenyl) porphine-iron(III) chloride on pyridyl-functionalized crosslinked poly(vinyl alcohol) and the catalytic activity of the adduct towards oxidation of selected organic substrates by hydrogen peroxide. The obtained adduct was characterized by UV/vis and IR spectroscopies. It showed a noticeable lignin-peroxidase-like catalytic activity; moreover a dramatic activity enhancement was observed in the presence of Mn(2+) under certain experimental conditions, so the preparation could well be classified as a manganese-peroxidase-like catalyst leading to a transient Mn(III) species. Conversion yields for some aromatic compounds (bio)chemically related to lignin, kinetics and operational features of the adduct are also reporte
Highly selective and sensitive fluorescence optode membrane for uranyl ion based on 5-(9-anthracenylmethyl)-5-aza-2,8-dithia[9],(2,9)-1,10-phenanthrolinophane
No full textA highly selective and sensitive fluorescent sensor for the determination of uranyl ion is developed. The
sensing membrane was prepared by incorporating 5-(9-anthracenylmethyl)-5-aza-2,8-dithia[9],(2,9)-1,10-
phenanthrolinophane as fluoroionophore in the plasticized poly(vinyl chloride) membrane containing 2-
nitrophenyloctylether as plasticizer. The proposed sensor displays a wide linear response range of 1.0 x
10-10 to 1.0 x 10-3 M with a low limit of detection of 2.7 x 10-11 M in solution at pH 4.0. This sensor has
a relatively fast response time of less than three min. In addition to high stability and reproducibility, it
shows a unique selectivity towards uranyl ion with respect to common coexisting cations. The sensor can
be regenerated by exposure to a solution of ethylene diamine tetraacetic acid. The proposed sensor was
then applied to the determination of uranyl in water samples with satisfactory result
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
Re(I) derivatives functionalized with thioether crowns containing the 1,10-phenanthroline subunit as a new class of chemosensors
No full textA series of luminescent fac-[Re(CO)3(L)(NN)]+ complexes, where L is a pyridine or an imidazole and NN is
the 1,10-phenanthroline subunit of mixed donor pentadentate thioether crowns have been synthesised
and their luminescence properties have been analysed. Then, heterometallic Re(I)/Au(I) complexes, with
the Au(I) fragment bonded directly to the imidazole ligand, and heterometallic Re(I)/Ag(I) complexes, with
the silver fragment coordinating the S-donor thioether linker of the rings have also been prepared.
Analysis of their luminescence properties showed a considerable blue shift of the emission maxima for
the Re(I)/Ag(I) derivatives, upon coordination of the silver centre to the S-donor atoms of the aliphatic
chain of the macrocyclic units
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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