1,720,971 research outputs found

    Triterpenoids as new promising anticancer drugs

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    Triterpenoids are structurally diverse organic compounds, characterized by a basic backbone modified in multiple ways, allowing the formation of more than 20 000 naturally occurring triterpenoid varieties. Several triterpenoids, including ursolic and oleanolic acid, betulinic acid, celastrol, pristimerin, lupeol, and avicins possess antitumor and anti-inflammatory properties. To improve antitumor activity, some synthetic triterpenoid derivatives have been synthesized, including cyano-3,12-dioxooleana-1,9 (11)-dien-28-oic (CDDO), its methyl ester (CDDO-Me), and imidazolide (CDDO-1m) derivatives. Of these, CDDO, CDDO-Me, and betulinic acid have shown promising antitumor activities and are presently under evaluation in phase I studies. Triterpenoids are highly multifunctional and the antitumor activity of these compounds is measured by their ability to block nuclear factor-kappa B activation, induce apoptosis, inhibit signal transducer, and activate transcription and angiogenesis. Anti-Cancer Drugs 20:880-892 (C) 2009 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The 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

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    “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

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    We 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

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    We 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

    Author Index

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    Proteasome inhibitors sensitize ovarian cancer cells to TRAIL induced apoptosis

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    In the present study we have explored the sensitivity of ovarian cancer cells to TRAIL and proteasome inhibitors. Particularly, we have explored the capacity of proteasome inhibitors to bypass TRAIL resistance of ovarian cancer cells. For these studies we have used the A2780 ovarian cancer cell line and its chemoresistant derivatives A2780/DDP and A2780/ADR, providing evidence that: (i) the three cell lines are either scarcely sensitive (A2780 and A2780/ADR) or moderately sensitive (A2780/DDP) to the cytotoxic effects of TRAIL; (ii) the elevated c-FLIP expression observed in ovarian cancer cells is a major determinant of TRAIL resistance of these cells; (iii) proteasome inhibitors (PS-341 or MG132) are able to exert a significant pro-apoptotic effect and to greatly enhance the sensitivity of both chemosensitive and chemoresistant A2780 cells to TRAIL; (iv) proteasome inhibitors damage mitochondria through stabilization of BH3-only proteins, Bax and caspase activation and significantly enhance TRAIL-R2 expression; (v) TRAIL-R2, but not TRAIL-R1, mediates the apoptotic effects of TRAIL on ovarian cancer cells. Importantly, studies on primary ovarian cancer cells have shown that these cells are completely resistant to TRAIL and proteasome inhibitors markedly enhance the sensitivity of these cells to TRAIL. Given the high susceptibility of ovarian cancer cells to proteasome inhibitors, our results further support the experimental use of these compounds in the treatment of ovarian cancer

    koamabayili/VECTRON-author-checklist: VECTRON author checklist

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    We 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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