1,720,977 research outputs found
Structural features of the Cu2+ complex with the rat Aβ(1-28) fragment
No full textThe interaction between Cu(II) and the rat amyloid b (1–28) fragment in micellar solutions at pH 7.5 was investigated by CD and NMR spectroscopy; the proton–copper distances were used in restrained molecular dynamics simulations to obtain a structural model of the Cu(II) complex
Specific interactions of Bi(III) with Cys-Xaa-Cys unit of a peptide sequence
No full textThe medicinal application of bismuth compounds is focused in two fields: antimicrobial and anticancer. Bi(III) complexes have been used in medicine as an effective treatment of microbial infections, such as
peptic ulcers, diarrhoea, gastritis and syphilis. 212Bi and 213Bi are strong a-particle emitters, which, bound to specific ligands, could be promising targeted radio-therapeutic agents for the treatment of
cancer. In this work, the coordination of bismuth to three peptides with the Cys-Xaa-Cys motif was studied by potentiometric, spectroscopic, mass spectrometric and NMR methods. We have shown, that sulfur atoms from cysteines are critical donors for the coordination of Bi(III). Our investigation provides insight towards an understanding of the chemistry of bismuth-containing complexes and may lead to the further application of this metal in medicine
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Fine tuning the structure of the Cu2+ complex with the prion protein chicken repeat by proline isomerization
No full textThe interaction between the single hexarepeat unit of chicken prion protein [ChPrP(54–59)] and Cu(II) was investigated by NMR, finding different coordination modes for the trans/trans and cis/trans isomers
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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
Tandem repeat-like domain of "similar to prion protein" (StPrP) of Japanese pufferfish binds Cu(II) as effectively as the mammalian protein
No full textThe main structural domains of prion proteins, in particular the N-terminal region containing characteristic amino acid repeats, are well conserved among different species, despite divergence in primary
sequence. The repeat region seems to play an important role, as verified by pathogenicity only observed in organisms having repeats composed of eight residues. In this work three different peptides belonging to the tandem repeat region of StPrP-2 from the Japanese pufferfish Takifugu rubripes have been considered; the coordination modes and conformations of their complexes with Cu(II) have been investigated by using potentiometric titrations, spectroscopic data, and restrained molecular dynamics simulations. In all cases the histidine imidazole(s) provide the anchoring site for copper, with the further involvement of amide nitrogens depending on the peptide sequence and on pH. An increase in copper binding affinity
has been observed going from the shortest peptide, corresponding to a single repeat and containing two histidines, to the longest one, encompassing three repeats with six histidines
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