1,721,131 research outputs found
Thiosilanes in sulfur chemistry: a general approach to silyl thiaheterocycles and their use in stereoselective synthesis.
No full textHydroxytyrosol rich-mixture from olive mill wastewater and production of green products by feeding Rhodopseudomonas sp. S16-FVPT5 with the residual effluent
No full textThis study disserts on the exploitation of olive mill wastewater (OMW) for the production of both bio-based poly-β-hydroxybutyrate (PHB) and hydrogen (H 2 ) by using the residual effluent as feedstock for growing purple bacteria after the recovery of hydroxytyrosol-rich mixtures. In particular, Rhodopseudomonas sp. S16-FVPT5 was fed with either the virgin OMW or dephenolized-OMW (d-OMW). For polyphenols removal, the OMW was treated with activated carbon; subsequently, acidified ethanol (pH = 3.1) at 50 °C was used as extractor solvent for obtaining hydroxytyrosol-rich mixtures. The maximum hydroxytyrosol content in the resultant polyphenolic mixture was 2.02 g/L. The highest co-production of PHB (315 mg PHB/L) and H 2 (2236 mL H 2 /L) were achieved feeding Rhodopseudomonas sp. S16-FVPT5 with pure d-OMW. The highest hydrogen yield (4.55 L(H 2 )/L d-OMW ) was obtained feeding the bacterium with d-OMW, diluted at 25%; by increasing the content of d-OMW into the culture broth the hydrogen yield progressively decreased. Lower results were obtained by feeding the bacterium with a synthetic medium, the cumulative hydrogen was 1855 mL H 2 /L); the PHB was 101 mg PHB/L. The highest theoretical light conversion efficiency was 2.36% with the synthetic medium and 1.99% when feeding Rhodopseudomonas sp. S16-FVPT5 with d-OMW diluted with water 50%, v/v
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
Evaluation of selenide, diselenide and selenoheterocycle derivatives as carbonic anhydrase I, II, IV, VII and IX inhibitors
No full textA series of selenides, diselenides and organoselenoheterocycles were evaluated as carbonic anhydrase (CA, EC 4.2.1.1) inhibitors against the human (h) isoforms hCA I, II, IV, VII and IX, involved in a variety of diseases among which glaucoma, retinitis pigmentosa, epilepsy, arthritis and tumors etc. These investigated compounds showed inhibitory action against these isoforms and some of them were selective for inhibiting the cytosolic over the membrane-bound isoforms, thus making them interesting leads for the development of isoform-selective inhibitors
Fluoride-induced proto- and carbo-desilylation of S,S-, O,O- and O,S-silylated acetals: an insight into the chemical and stereochemical reaction outcome
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