1,720,979 research outputs found
Projection reconstruction MR microscopy for the ex vivo evaluation of trabecular bone structure
No full textConformational analysis on segments of charged polysaccharides. The case of hyaluronic acid dimer and chondrosine
No full textHYDROGEN-BONDING AND CONFORMATION OF AGAROSE IN METHYL SULFOXIDE AND AQUEOUS SOLUTIONS INVESTIGATED BY 1H AND 13C NMR SPECTROSCOPY
No full textCondrocyte-alginate bioconstructs: A nuclear magnetic resonance relaxation study
No full textProton nuclear magnetic resonance (NMR)
relaxometry can give informations about hydrogel scaffold
properties. As these properties can be modified with
culture time and conditions according to scaffold biodegradability
and new tissue biosynthesis, the aim of this
research was to test the efficiency of this noninvasive
NMR technique in the follow-up of 3D cultures for tissue
engineering. The distributions of proton relaxation times
T1 and T2 have been measured on cylindrical gel samples
of different types of alginate, in the presence or absence
of hyaluronate, in gels or bioconstructs with encapsulated
chondrocytes cultured for 30 days in normal or
reduced weight conditions. It was found that T2 increases
with the mannuronate/guluronate ratio in alginate samples
and with the presence of hyaluronate. The distributions
of both T1 and T2 result wider for bioconstructs cultured
in normal gravity than for those cultured in
reduced weight conditions. Neither cell growing nor collagen
production but only GAG neosynthesis have been
demonstrated in our experimental conditions. In conclusion,
T2 is sensitive to the gel properties (possibly to the
rigidity of macromolecular components). The homogeneity
of bioconstructs can be monitored by the distribution
of T1 and T2. We propose that nonspatially resolved
NMR relaxometry can efficiently be used in monitoring
tissue development in a biodegradable scaffold for tissue
engineering
A better understanding of the properties of alginate solutions and gels by quantitative magnetic resonance imaging (MRI)
No full text
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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