1,721,158 research outputs found
Circulating cytokines as biological indicators for PE and ceramic articulations
No full textWe studied the role of cytokines (TNF-α, IL-6,IL-1β, TGF-β) as markers of osteolysis in patients who underwent to a hip prosthesis implantation subdivided in two groups: group A with an ultrahigh molecular weight polyethylene (UHMWPE) insert articulating against a metal ball head , and group B with an all alumina ceramic combination. Profibrogenic (TGF-β) and pro-inflammatory cytokines (TNF-α, IL-6,IL-1β) are secreted by the periprosthetic synovial-like fibrous membrane in hip artificial implants. They are secreted by inflammatory activated cells and trigger the cascade of biochemical events leading to the activation of osteoclasts and bone resorption. A statistically significant increase of TGF-β serum levels was observed between TGF-β values in implanted patients as compared to normal subjects and between TGF-β values after versus before implantation in Group A. A progressive decrease in TNF-α and IL-6 serum levels has been observed in both Groups, when compared with the initial values before the implantation. IL-1β levels decreased up to 60 months after the implantation Our data suggest that monitoring circulating cytokines could be a good indicator for the proliferation and activity of the periprosthetic synovial-like membrane and potential osteolysis. This could allow for an adequate early treatment
Pro-inflammatory and anti-inflammatory circulating cytokines and periprosthetic osteolysis
Full text linkWe investigated the circulating levels of the main cytokines involved in bone resorption (IL-1β, IL-6, TNF-α), prostaglandins (PGE2) and metalloproteases (MMP-1), as possible early markers of osteolysis, in the serum of eight patients with periprosthetic osteolysis and ten patients without osteolysis. All had received a cementless hip prosthesis (ABG-1). We also assessed the serum levels of IL-11 and TGF-β anti-inflammatory cytokines exerting protective effect on bone resorption. The mean serum levels of IL-1β, IL-6, TNF-α, TGF-β, MMP-1, and PGE2 in patients with periprosthetic osteolysis did not differ significantly from those of patients without osteolysis or from those of normal controls. IL-11 serum levels were not detectable at all in any of the patients, while they were detected within normal reference values in the control subjects (significant inverse correlation). We believe that circulating cytokines cannot be regarded as markers of osteolysis, a condition characterised by a local inflammation without systemic signs of inflammation. On the contrary, the undetectable levels of IL-11 in implanted patients could provide evidence for a lack of balance between pro- and anti-inflammatory cytokines in these patients
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
Cyclosporin A in Systemic Lupus Erythematosus: side effects and causes of discontinuation.
No full textAntibodies to Carbonic Anidrase II as a possible marker of tissue damage in Asthma and Primary Lung Disease.
No full textDispelling 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
- …
