1,720,975 research outputs found
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
Jetkit, Unifast and Duralay resins regulate the behavior of HGFs cells through long non-coding RNA hotair transcription and the MMP2, MMP9, IL6 genes expression.
No full textVariations 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
Effects of ethanol and dimethyl sulfoxide on solubility and cytotoxicity of the resin monomer triethylene glycol dimethacrylate.
No full textSeveral in vitro studies have reported contrasting values for triethylene glycol-dimethacrylate (TEGDMA) concentrations shown to induce cytotoxic effects. The aim of this study was to evaluate the effective concentrations of TEGDMA reached under the routine experimental conditions used in biocompatibility in vitro tests and determines changes in cytotoxicity and the associated production of reactive oxygen species (ROS) based on different TEGDMA solutions. TEGDMA was added to cell culture medium either directly or previously dissolved in dimethyl sulfoxide (DMSO) or ethanol (EtOH), both in the presence and absence of cells. Intracellular and extracellular TEGDMA concentrations were determined by high performance liquid chromatography (HPLC). The cytotoxicity effects of TEGDMA preparations were determined in 3T3-fibroblasts by 3-(4,5 dimethyiazol-2-1)-2-5-diphenyl tetrazolium bromide assay. The production of ROS was measured by flow cytometry. In the absence of cells the effective final TEGDMA concentrations obtained in Dulbecco's Modified Eagle Medium were significantly lower than the nominal one. When 2 mmol/L TEGDMA was first solubilized in DMSO or EtOH, a significant decrease in cell viability, and an increase in ROS production-compared to pure TEGDMA-was observed. After 2 h of incubation, TEGDMA previously dissolved in DMSO or ETOH was reduced by 15% and 20%, respectively, whereas otherwise it remained unaffected. Our results demonstrate that the effective concentration of TEGDMA dissolved in culture medium (in the presence or absence of solvents) does not concur with the nominal one. Therefore, the presence of the utilized solvents does not substantially alter the monomer solubility but eases its entrance into the cells thus improving its cytotoxic potenc
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
Influence of Self-polymerizing Dental Resins on MMP-2 AND MMP-9 Genes
No full textObjective: The present in vitro study aimed to evaluating the potential cytotoxicity of self-polymerizing dental resins on human gingival fibroblasts (HGFs) isolated from healthy patients. Moreover, the study assessed the quantitative gene expression of matrix metalloproteinases (MMP) -2 and -9 in HGFs stimulated with the same resins.
Method: Three different self-polymerizing dental resins (JetKit, Duralay, Unifast III) were tested. HGFs were isolated from fragments of gingival tissues removed from healthy patients. The determination of cytotoxic activity on HGFs was estimated by standard MTT-test (3,[4,5-dimethylthiazol-2]2,5 difeniltetrazolium bromide). Differently, the quantitative gene expression analyses of MMP-2 and MMP-9 were carried out with QRT-PCR on a StepOne System. The quantification was made in 48-well plates with a TaqMan Universal MasterMix. Statistical analysis of data were performed by ANOVA.
Result: After 24h MTT assay showed that all the materials tested did not cause a significant cytotoxic effect in HGFs. Moreover, the QRT-PCR, MMP-2 and MMP-9 genes were up-regulated in HGFs treated with all the tested self-polymerizing dental resins compared to the controls. The cells treated with Duralay showed an overxpression of MMP-2 compared to cells treated with JetKit and Unifast III; coversely, the MMP-9 gene was over-expressed in HGFs treated with JetKit compared to cells treated with Duralay and Unifast III.
Conclusion: Our results suggest that the tested dental resins caused a low degree of cytotoxicy, nevertheless they showed the ability to modulate the transcriptional regulation of MMP-2 and MMP-9 genes in HGFs
RESIN REGULATION OF IL6 AND RELATED RECEPTORS TRANSCRIPTION IN HGFs
No full textObjective: The primary aim of the present in vitro study was the assessment of the potential cytotoxicity of self-polymerizing dental resins on human gingival fibroblasts (HGFs) isolated from healthy patients. The secondary goal of this investigation was the evaluation of the quantitative gene expression of IL6, and its receptors (gp80 and gp130).
Method: Three different self-polymerizing dental resins (JetKit, Duralay, Unifast III) were analyzed. HGFs were isolated from fragments of gingival tissues removed from healthy patients. The cytotoxic activity analysis on HGFs was made using standard MTT-test (3,[4,5-dimethylthiazol-2]2,5 difeniltetrazolium bromide). Conversely, the quantitative determinations of IL6, gp80, gp130 gene expression were evaluated by means of QRT-PCR on a StepOne System. The quantification was made in 48-well plates with a TaqMan Universal MasterMix. Statistical analysis of data were performed by ANOVA.
Result: MTT data showed that all the materials tested caused a not significant toxic effect in HGFs. As to the QRT-PCR, IL6, gp80 and gp130 genes were upregulated in HGFs stimulated with all the tested dental resins. Furthermore, IL6 and its receptors were overexpressed in HGFs treated with JetKit compared to HGFs treated with Duralay and Unifast III.
Conclusion: Our results showed that all tested self-polymerizing dental resins materials involved IL6 as a potential regulator of the epigenetic mechanisms by means of the inflammatory process
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