1,720,978 research outputs found
Fluoride-containing bioactive glasses inhibit pentose phosphate oxidative pathway and glucose 6-phosphate dehydrogenase activity in human osteoblasts
No full textBioactive glasses such as Hench's 45S5 (Bioglass®) have applications to tissue engineering aswell as bone repair, and the insertion of fluoride in their composition has been proposed to enhancetheir bioactivity. In view of a potential clinical application, we investigated whether fluoride-containingglasses exert toxic effects on human MG-63 osteoblasts, and whether and how fluoride, which isreleased in the cell culture medium, might play a role in such cytotoxicity. A 24 h incubation with 50μg/ml (12.5 μg /cm2) of fluoride-containing bioactive glasses termed HCaCaF2 (F content: 5, 10 and15% mol) caused the release of lactate dehydrogenase in the extracellular medium (index ofcytotoxicity), the accumulation of intracellular malonyldialdehyde (index of lipoperoxidation), and theincrease of glutathione consumption. Furthermore, fluoride-containing glasses inhibited the pentosephosphate oxidative pathway and the glucose 6-phosphate dehydrogenase activity. These effects areascribable to the fluoride content/release of glass powders, since they were mimicked by NaF solutionsand were prevented by dimethyl sulfoxide and tempol (two radical scavengers), by superoxidedismutase (a superoxide scavenger), and by glutathione (the most important intracellular antioxidantmolecule), but not by apocynin (an inhibitor of NADPH oxidase). The presence of fluoride-containingglasses and NaF caused also the generation of reactive oxygen species, which was prevented bysuperoxide dismutase and catalase. The data suggest that fluoride released from glasses is the cause ofMG-63 cell oxidative damage and is independent of NADPH oxidase activation. Our data provide a newmechanism to explain F ̅ ions toxicity: fluoride could trigger, at least in part, an oxidative stress viainhibition of the pentose phosphate oxidative pathway and, in particular, through the oxidativeinhibition of glucose 6-phosphate dehydrogenase
Variation of vascular and blood indicators of early endothelial dysfunction after root canal therapy: A clinical and biomolecular study
No full textAim: Apical periodontitis (AP) is correlated with a higher risk of developing cardiovascular disease (CVD). No data currently exist to suggest that endothelial dysfunction (ED) improves after endodontic treatment in patients who have AP, despite a link between chronic AP and ED. This study was designed to investigate the expression of early ED markers in young adults with chronic AP, before and after root canal treatment. Methodology: 41 subjects (20 controls and 21 patients with AP) were examined at enrolment. Patients with AP were also assessed 2 and 12 months after treatment. ENDO-PAT was used to measure endothelial flow reserve (EFR) and ELISAs were used to assess plasma levels of interleukin (IL)-1, IL-6 and TNF-alpha, vasoconstrictor ED endothelin (ET)-1, the circulating endothelial adhesion markers intercellular adhesion molecule-1 (ICAM)-1/ CD54 and soluble vascular cellular adhesion molecule-1 (sVCAM)-1/CD106, soluble CD14, and the endothelial leukocyte adhesion molecule E-selectin. Results: Baseline serum levels of ET-1, ICAM-1, E-selectin, IL-1, and sCD14 were elevated in patients with AP compared to the control group. There was no macroscopic evidence of reduced EFR in either group. Treatment for AP was associated with reduced inflammation and improved early ED, indicated by a lowering of IL-1, sCD14, ET-1, ICAM-1/ CD54 and E-selectin levels to resemble those of control subjects. Conclusions: Early vascular ED may be driven by AP but is reversible with effective endodontic treatment
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
Role of cold balanced salt solution (Bss) in the prophylaxis of cystoid macular edema after cataract surgery: A prospective randomized study
Full text linkPurpose: To evaluate the postoperative effect on central retinal macular thickness of a cooled irrigating eye solution used during cataract surgery. Patients and Methods: In this prospective, single-center study, 100 eyes of 50 patients (26 males and 24 females) were evaluated with spectral domain optical coherence tomography (SD-OCT) before and after phacoemulsification for senile cataract. Eyes were randomly divided into two groups based on the irrigating solution used during surgery: Group 1, 50 eyes received intraoperative irrigating solution at room temperature (~20.0±0.1°C); and Group 2, 50 fellow eyes received cold intraoperative irrigating solution (2.7±0.1°C). Changes in central macular thickness (CMT) were evaluated in both groups by SD-OCT macular raster scan for the nine Early Treatment of Diabetic Retinopathy Study (ETDRS) subfields and total macular volume, performed pre-surgery, and 1 and 4 weeks post-surgery. Results: Despite there being no significant differences in variables between the two groups preoperatively, significant increases in CMT were observed at 1 week after surgery in both groups (p=0.02 and p=0.03, respectively), as well as in total macular volume (p<0.0001 and p=0.02, respectively). Inter-subgroup analysis showed a significant reduction in CMT (p=0.03) and total macular volume (p=0.001) at 1 week post-surgery in Group 2 compared to Group 1, whereas no significant differences were observed at 4 weeks. Conclusion: The use of a cooled irrigating eye solution during phacoemulsification may be beneficial in preventing the possible development of postoperative macular thickening. Further clinical studies may support this finding
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
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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