1,721,662 research outputs found
Tissue regeneration in osteoarthritis: the effects of inflammatory cytokines on bioengineering strategies to repair arthritic joints
No full textOsteoarthritis (OA) is the most common form of arthritis worldwide. Historically, treatments for OA have been analgesics, physiotherapy, joint injections and eventually joint replacement surgery. With the advent of tissue engineering (TE), there has been considerable interest in exploiting these techniques to devise new treatments for OA. Despite the development of skeletal stem cell (SSC) constructs aimed at creating viable cartilage and bone, few studies have examined the effects of inflammatory cytokines present in OA synovial tissues, on such constructs. Here, both in vitro and in vivo approaches were used to examine the effects of cytokines on the integrity of such bone constructs.This work confirms IL-1β is a key cytokine for enhancing osteogenic differentiation in OA, whereas TNFα is inhibitory. OA supernatants were obtained from synovial tissue of patients undergoing hip or knee arthroplasty. Most OA supernatants produced an inhibitory effect on osteogenic differentiation in co-cultures with HBMSCs; a minority had additive osteogenic effects, consistent with a more inflammatory subtype of OA. miRNA profiles were analysed for the first time in these co-cultures, producing valuable insights into the pathways through which IL-1β may mediate its effects on osteogenic differentiation. Finally, ex vivo and in vivo models of bone formation, not previously used in the OA field, corroborated the findings of these in vitro studies. These data support the utility of focusing on upregulating IL1-β and inhibiting TNFα to modify existing bone TE strategies being developed locally, for use in the future treatment of OA. Findings were similar with other cell types such as induced pluripotent stem cells, which show promise for future TE strategies. This work also validated the organotypic chick femur and subcutaneous implant models for the future testing of other bioactive factors or miRNAs for incorporation into bone TE approaches for the management of OA
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
Anti-TNF-induced lupus
No full textThe use of protein-based anti-TNF-alpha therapies such as antibodies and soluble TNF-alpha receptors is commonly associated with the induction of autoantibodies, whereas anti-TNF-induced lupus (ATIL) is rare. ATIL can occur with any of the available TNF inhibitors, but the frequency and clinical characteristics of ATIL vary between different drugs. Cutaneous, renal and cerebral involvement as well as dsDNA antibodies are more common in ATIL compared to classical drug-induced lupus (DIL), suggesting different pathogenic mechanisms of ATIL and DIL. True ATIL must be clinically differentiated from mixed CTD, SLE or overlap syndromes unmasked, but not induced, by anti-TNF-alpha treatment of unclassified polyarthritis. The pathogenesis of ATIL is still unknown. Concomitant immunosuppression can reduce autoantibody formation in ATIL, and withdrawal of anti-TNF-alpha therapy usually leads to resolution of symptoms. Steroids and/or immunosuppressive therapy may be required in severe cases
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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