1,721,009 research outputs found
Biocatalysis in non-conventional media—ionic liquids, supercritical fluidsand the gas phase
No full textStability and activity of immobilised penicillin G amidase in ionic liquids at controlled aw
No full textDespite the great interest in ionic liquids as novel solvents for biocatalysis, there is still no clear idea of their influence on the stability and the activity of enzymes. Here we analysed the activity and stability of PGA in six different ionic liquids, having different cations ([bmim] and [omim]) and anions (CH3OSO3 2, PF6 2 and BF4 2). To be active in ionic liquids, PGA-450 requires an acceptable hydration (aw . 0.60), as in organic solvents. PGA is highly stable in [bmim][PF6] and [bmim][BF4], and catalytic activity, assayed by studying the synthesis of the amide of L-phenylglycine methyl ester with methyl phenylacetate, in these ILS is comparable to that obtained in toluene
Synthesis of octyl glucopyranoside by almond beta-glucosidase adsorbed onto Celite R-640
No full textComputational methods to rationalize experimental strategies in biocatalysis
No full textComputational methods are more and more widely applied in biocatalysis to gain rational guidelines, to orient experimental planning and, ultimately, to avoid expensive and time-consuming experiments. In this respect, molecular modelling, multivariate statistical analysis and chemometrics in general are useful computational tools, although they follow completely different investigative approaches
Effect of Microwave Radiation on Enzymatic and Chemical Peptide Bond Synthesis on Solid Phase
Full text linkPeptide bond synthesis was performed on PEGA beads under microwave radiations. Classical chemical coupling as well as
thermolysin catalyzed synthesis was studied, and the effect of microwave radiations on reaction kinetics, beads’ integrity, and
enzyme activity was assessed. Results demonstrate that microwave radiations can be profitably exploited to improve reaction
kinetics in solid phase peptide synthesis when both chemical and biocatalytic strategies are used
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
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