1,720,990 research outputs found
Natural, Designed and Engineered Metalloenzymes: Structure, Catalytic Mechanisms and Applications
Full text linkBioinorganic chemists have become engaged in the challenge of elucidating the molecular mechanisms that govern how protein scaffolds modulate the properties of metal cofactors. One of the most powerful tools for this purpose consists of the construction of model systems replicating the structural and functional features of their natural counterparts. Metalloenzymes also represent a significant source of inspiration: Researchers have attempted for decades to construct efficient and selective catalysts by engineering metal binding sites into natural or de-novo-designed protein scaffolds. From this perspective, the construction of artificial metalloenzymes goes beyond the goal of elucidating the catalytic mechanism of natural biocatalysts and aims to manipulate or improve their catalytic properties into tailor-made systems.
This Special Issue of the International Journal of Molecular Sciences has collated some recent contributions involving the development of artificial metalloenzymes for challenging biocatalytic applications. Several strategies have been successfully applied to this purpose, and some prominent examples are reported herein
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
Designing Covalently Linked Heterodimeric Four-Helix Bundles
No full textDe novo design has proven a powerful methodology for understanding protein folding
and function, and for mimicking or even bettering the properties of natural proteins.
Extensive progress has been made in the design of helical bundles, simple structural
motifs that can be nowadays designed with a high degree of precision. Among helical
bundles, the four-helix bundle is widespread in nature, and is involved in numerous and
fundamental processes. Representative examples are the carboxylate bridged diiron
proteins, which perform a variety of different functions, ranging from reversible dioxygen
binding to catalysis of dioxygen-dependent reactions, including epoxidation desaturation, monohydroxylation, and radical formation. The “Due Ferri” (two-irons; DF) family of proteins is the result of a de novo design approach, aimed to reproduce in
minimal four-helix bundle models the properties of the more complex natural diiron
proteins, and to address how the amino acid sequence modulates their functions.
The results so far obtained point out that asymmetric metal environments are essential
to reprogram functions, and to achieve the specificity and selectivity of the natural
enzymes. Here, we describe a design method that allows constructing asymmetric fourhelix
bundles through the covalent heterodimerization of two different α-helical
harpins. In particular, starting from the homodimeric DF3 structure, we developed a
protocol for covalently linking the two α2 monomers by using the Cu(I) catalyzed
azide–alkyne cycloaddition. The protocol was then generalized, in order to include the
construction of several linkers, in different protein positions. Our method is fast, low cost,
and in principle can be applied to any couple of peptides/proteins we desire to link
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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