1,720,964 research outputs found
Human adipose-derived stem cells (hASCs) proliferate and differentiate in osteoblast-like cells on trabecular titanium scaffolds
Full text linkAbstract
The use of stem cells in regenerative medicine is an appealing area of research that has received a great deal of interest in recent years. The population called human adipose tissue-derived stem cells (hASCs) share many of the characteristic of its counterpart of marrow including extensive proliferative potential and the ability to undergo multilineage differentiation along classical mesenchymal lineages: adipogenesis, chondrogenesis, osteogenesis, and myogenesis. The aim of this study was to evaluate with biochemical and morphological methods the adhesion and differentiation of hASCs grown on trabecular titanium scaffolds. The hASCs isolated from subcutaneous adipose tissue after digestion with collagenase were seeded on monolayer and on trabecular titanium scaffolds and incubated at 37 degrees C in 5% CO(2) with osteogenic medium or control medium.The results showed that hASCs were able to adhere to titanium scaffolds, to proliferate, to acquire an osteoblastic-like phenotype, and to produce a calcified extracellular matrix with protein, such as, decorin, fibronectin, osteocalcin, osteonectin, osteopontin, and type I collagen. These data suggest that this kind of scaffold/cells construct is effective to regenerate damaged tissue and to restore the function of bone tissue
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
Assessment of human herpesvirus-6 infection in mesenchymal stromal cells ex vivo expanded for clinical use.
No full textInfection or reactivation of human herpesvirus (HHV)-6 represents a potentially serious complication (often involving the central nervous system) in patients receiving either solid organ or hematopoietic stem cell transplantation. The objective of this study was to assess the risk of HHV-6 infection/reactivation in mesenchymal stromal cells (MSCs). MSCs are multipotent cells displaying immunomodulatory properties that have been already successfully used in the clinical setting to enhance hematopoietic stem cell engraftment and to treat steroid-refractory acute graft-versus-host disease. We analyzed 20 samples of ex vivo expanded MSCs, at different passages of culture, isolated both from bone marrow and from umbilical cord blood. Through Western blotting and immunocytochemistry techniques, we investigated the presence of the HHV-6 receptor (CD46) on cell surface, whereas the presence of HHV-6 DNA was evaluated by nested polymerase chain reaction assay. All of the MSC samples tested were positive for the virus receptor (CD46), suggesting their potential susceptibility to HHV-6. However, none of the MSC samples derived from cultures, performed in the perspective of clinical use, was found to harbor HHV-6. This preliminary observation on a consistent number of MSC samples, some of them tested at late in vitro passages, indicates a good safety profile of the product in terms of HHV-6 contamination. Nevertheless, it remains important to set up in vitro experimental models to study MSCs' susceptibility to HHV-6 (and HHV-7) infection, to verify their capacity to integrate the virus into cellular DNA, and to investigate which experimental conditions are able to induce virus reactivation
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
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
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