1,720,962 research outputs found
Cytotoxic effects of damnacanthal and damnacanthal-doxorubicin combination on human breast cancer cell line (MCF-7)
Full text linkDamnacanthal is a biologically active antraquinone derivative isolated from roots of Morinda sp., belonging to the Rubiaceae family. This plant has a long history of use
as a food in tropical regions throughout the world. The purpose of this study was to examine the in vitro cytotoxicity effect of damnacanthal and combination of
damnacanthal with doxorubicin on human breast carcinoma (MCF-7). MTT assay was used to determine the cytotoxic properties of damnacanthal towards various cancer cell lines, normal cell lines and immune cells. Results showed that damnacanthal displayed strong killing effect towards the cancerous cell lines and moderate effect towards normal cells lines. Among the cancer cell lines, damnacanthal showed strong cytotoxic towards MCF-7 cells with CD50 8.2 ± 0.7 μg/mL after 72 hours treatment period. In contrast, no cytotoxicity was detected in primary mouse splenocytes, mouse thymocytes and mouse bone marrow. In particular, damnacanthal showed cytotoxicity in a dose- and time-dependent manner in the MTT assay. Thus, MCF-7 cells were used to determine the mode of cell death with damnacanthal alone and combination with doxorubicin. In the cell viability assay, the percentage viability of MCF-7 cells is lower when the cells are treated with combination of damnacanthal and doxorubicin than doxorubicin alone. In the
cell cycle with flow cytometry analysis, damnacanthal arrested the cell cycle of MCF-7 cells at G1 phase and doxorubicin arrested at G2/M phase. The percentage
population of MCF-7 cells enter sub G0 phase are increased when the cells were treated with combination of damnacanthal and doxorubicin. The mode of cell death
was mainly apoptosis by acridine orange/propidium iodide (AO/PI) dual staining method and Annexin V-FITC/PI assays. Gross morphology of treated cells observed through AO/PI showed the presence of blebbings cells, chromatin condensation and DNA fragmentation, indicating apoptosis. Annexin V-FITC/PI staining showed that substantial early apoptotic cells were detected in MCF-7 cells treated with
damncanthal alone and in combination with doxorubicin. The changes of percentage intracellular proteins were analyzed using flow cytometer. The percentage of Bcl-2 protein is higher than p53 protein in the control group. While in the treatment group, the percentage of Bcl-2 protein decreased significantly and p53 protein increased significantly. The changes of expression level of apoptotic related genes caused by damnacanthal and doxorubicin were profiled using multiplex gene expression profiler (GeXP). The expression levels of genes that give significant signal were not
much different at 12 and 24 hours. Out of 15 genes that were analyzed, four genes showed detection in expression level; BAX, p21, caspase-3 and caspase-7. The expression of these pro-apoptotic genes is up-regulated in the treated group compared to control. Among the treated group, the combination treatment of damnacanthal and doxorubicin showed higher expression level of these pro-apoptotic
genes. The findings in the intracellular protein detection and changes in the expression level of apoptotic related genes reflect that the mechanism of damnacanthal induced apoptosis in the human breast cancer cells was by the intrinsic and caspases induction pathway. In conclusion, damnacanthal is more toxic towards cancer cell lines rather than normal cell lines and primary cells and showed the
potential use as a promising agent for apoptosis induction alone and/or with combination with doxorubicin. The induction of apoptosis involved important proapoptotic
genes which are BAX, p53, p51 caspase-3 and caspase-7
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
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
Total Phenolic Content and Antioxidant Activity of Passiflora edulis Extract
Full text linkPassion fruit is a type of wild exotic plant in Malaysia. Common passion fruits planted in Malaysia are Passiflora edulis Sims (purple) and Passiflora edulis var flavicarpa (yellow). These fruits contain a high amount of antioxidants, polyphenols and vitamin C and are widely used as fruit juice, jam, and syrup product. However, there is a lack of information about the nutritional composition of the juice and seed of P. edulis (purple) cultivated in Malaysia. This study aims to determine the total phenolic contents, antioxidant activity and Vitamin C (ascorbic acid) content of P. edulis (purple) using two different solvent extraction, 70% of ethanol and 70% of methanol. The total phenolic content (TPC) was carried out by using Folin-Ciocalteu (FC) method, while the antioxidant activity was analysed using 1, 1-diphenyl-2-picrylhydrazyl (DPPH) assay to determine the IC50 value of extracted samples. Ascorbic acid content from fresh juice and seeds samples was analysed by using Indophenol (DCPIP) method. The result showed that the extraction using ethanol produced the highest TPC with 9.249±0.04 mg GAE/g in seeds and 0.0139±0.02 mg GAE/g in juice, respectively. The lowest IC50 value was obtained by sample extracted with ethanol, which was 83.85±4.66 mg/L in seed and 305.47±5.28 mg/L in juice. The seed sample (53.68±4.95 mg/100mg) exhibited a high ascorbic acid content compared to the juice sample (46.66±3.28 mg/100mg). In conclusion, seeds of P. edulis possessed the strongest antioxidant activity and vitamin C content. This study could contribute to information regarding the phytochemical constituents and suitable solvent for extraction of phenolic compounds that can act as antioxidants and thus promote health effects on the human body
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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