1,720,964 research outputs found
Fast and Efficient Microwave-Assisted Synthesis of Perylenebisimides
No full textPerylene-3,4,9,10-tetracarboxylic acid bisimides have been widely studied as industrial pigments. Lately, these dyes have drawn considerable attention because of applications as photocatalysts and organic semi-conductors. Here, we report a novel method for fast and efficient synthesis of many different perylenebisimides, based on microwave-assisted reactions
Chemical–physical analysis of a tartrate model compound for TACE inhibition
No full textWe have synthesized and done an extensive chemical–physical analysis of the behavior of a new compound,
named MBET306, a synthetic precursor of the recently discovered tartrate-based inhibitors of the protein
Tumor Necrosis factor-a Converting Enzyme (TACE). Experimental and theoretical data have shown that in
water solution MBET306 is overwhelmingly found as a monoanion at physiological pH, in a conformation
that differs substantially from that detected in the known co-crystal structures of MBET306 derivatives bound
to TACE. The body of collected experimental and theoretical data indicates that the monoanionic species
binds Zn(II) inducing a strong stabilization of the crystal-like arrangement of the central tartrate zinc-binding
group, lending support for a two step TACE docking mechanism via a zinc-bound intermediate. The
thorough chemical–physical characterization of the conformational behavior of free and zinc-bound
MBET306 in water bulk solution opens new avenues for the rational drug design of tartrate-based highly
specific TACE inhibitor
Unravelling Radicals Reactivity Towards Carbon Nanotubes Manipulation/Functionalization
Full text linkCarbon Nanotubes (CNTs) chemistry is under constant evolution, as a consequence of the deep interest
of the scientific community in finding new applications for these versatile materials. New and old synthetic protocols
are used for improving the control of the functionalization degree of the final materials and for offering to scientists
the possibility to fine-tune their final properties. In this Review, we focus the attention on radical reactions,
a class of protocols characterized by small number of steps, different degrees of functionalization and enhanced
solubility of the final modified CNTs, in the desired environment. The most well-known protocols are analysed
providing some relevant examples appeared in the literature in the last years, monitoring the new application fields
and giving insights into their mechanism in order to explain why these protocols are considered standard procedures for a wide number of
scientific groups
Ecotoxicological effects of graphene-based materials
No full textGraphene-based materials (GBMs) are currently under careful examination due to their potential impact on health and environment. Over the last few years, ecotoxicology has started to analyze all the potential issues related to GBMs and their possible consequences on living organisms. These topics are critically considered in this comprehensive review along with some considerations about future perspectives
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
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