1,720,976 research outputs found
Comparison of tetraacetylethylendiamine + sodium perborate and sodium hypochlorite cytotoxicity on L929 fibroblasts
No full textIntroduction: Tetraacetylethylenediamine in association with sodium perborate (TAED+P) can be suggested for its use as an endodontic disinfectant because of its antimicrobial activity against different bacterial species when used at low concentrations. The purpose of this study was to measure the cytotoxicity of TAED+P on L929 fibroblasts and to compare it with that of sodium hypochlorite (NaOCl). Methods: L929 fibroblasts were grown in Dulbecco Modified Eagle Medium containing 10% fetal calf serum (FCS) at 37°C and 5% CO 2. At confluence, cells were split, plated in a 96-well plate, and incubated for 24 hours to allow attachment. The two disinfectants TAED+P and NaOCI were tested at various concentrations. The neutral red uptake and the 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyl tetrazolium bromide assays were used to evaluate the cell viability. The 50% inhibitory dose values for both disinfectants were calculated and statistically analyzed. The effect of both disinfectants on fibroblast viability was also determined in the presence of various concentrations of FCS. One-way analysis of variance with post hoc analysis using Tukey multiple comparison test was used for parametric data. Results: Both disinfectants induced a dose-related loss of cell viability; TAED+P resulted less cytotoxic than NaOCI in all the examined experimental conditions. Conclusions: These data support the possible use of TAED+P as an endodontic irrigant. Further studies are required to analyze its antibacterial activity against endodontic pathogens
Enzyme-assisted photosensitization activates diVerent apoptotic pathways in Rose Bengal acetate treated HeLa cells
No full textα-Lipoic acid induces Endoplasmic Reticulum stress-mediated apoptosis in hepatoma cells
Full text linkHepatocellular carcinoma (HCC) is the most common liver cancer and a major cause of adult death. The current treatments for HCC suffer from drug resistance and poor prognosis; therefore, novel therapeutic agents are urgently needed. Phytochemicals have been proposed to treat a range of cancers. Among them, α-lipoic acid (α-LA), a naturally synthesized antioxidant found in various dietary animal and plant sources, prevents oxidant-mediated cell death in normal cells while inducing apoptosis in several cancer cell lines. Previously, we demonstrated that the treatment of hepatoma cells with α-LA induced apoptosis, which was preceded by the generation of reactive oxygen species (ROS) and activation of the p53 protein, a known inducer of mitochondria-mediated apoptosis. Several studies have shown that ROS-induced apoptosis is associated with endoplasmic reticulum (ER) stress and Unfolded Protein Response (UPR) activation. Herein, we investigated if α-LA-induced apoptosis in hepatoma cell lines was ER stress- and UPR-mediated by gene expression profiling analyses. UPR and ER stress pathways were the most up-regulated after treatment with α-LA. This finding, which has been confirmed by expression analyses of ER- and UPR-associated proteins, provides a better understanding of the molecular mechanisms behind the anti-tumoral action of α-LA on hepatoma cells
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-chlamydial activity of vaginal fluids: new evidence from an in vitro model
Full text linkIntroduction: We assessed the in vitro anti-chlamydial activity of fresh vaginal secretions, deciphering the microbial and metabolic components able to counteract Chlamydia trachomatis viability. Methods: Forty vaginal samples were collected from a group of reproductive-aged women and their anti-chlamydial activity was evaluated by inhibition experiments. Each sample underwent 16S rRNA metabarcoding sequencing to determine the bacterial composition, as well as 1H-NMR spectroscopy to detect and quantify the presence of vaginal metabolites. Results: Samples characterized by a high anti-chlamydial activity were enriched in Lactobacillus, especially Lactobacillus crispatus and Lactobacillus iners, while not-active samples exhibited a significant reduction of lactobacilli, along with higher relative abundances of Streptococcus and Olegusella. Lactobacillus gasseri showed an opposite behavior compared to L. crispatus, being more prevalent in not-active vaginal samples. Higher concentrations of several amino acids (i.e., isoleucine, leucine, and aspartate; positively correlated to the abundance of L. crispatus and L. jensenii) lactate, and 4-aminobutyrate were the most significant metabolic fingerprints of highly active samples. Acetate and formate concentrations, on the other hand, were related to the abundances of a group of anaerobic opportunistic bacteria (including Prevotella, Dialister, Olegusella, Peptostreptococcus, Peptoniphilus, Finegoldia and Anaerococcus). Finally, glucose, correlated to Streptococcus, Lachnospira and Alloscardovia genera, emerged as a key molecule of the vaginal environment: indeed, the anti-chlamydial effect of vaginal fluids decreased as glucose concentrations increased. Discussion: These findings could pave the way for novel strategies in the prevention and treatment of chlamydial urogenital infections, such as lactobacilli probiotic formulations or lactobacilli-derived postbiotics
Human milk microbiota: correlations with fatty acids composition and diet in the first six months after delivery
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
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