1,720,989 research outputs found
Isolation of secondary metabolites from Annonaceae plants and their biological activities
No full text博士論文 (Doctoral dissertation
The potency of secondary metabolites from traditional medicine plants as anti cancer agent
Get PDFThe seconday metabolites from traditional medicine plants have played an important role incancer treatment. Exploration of natural active compounds from medicinal plants for cancertreatment has attracted substantial attention worldwide. Several secondary metabolites thatwere isolated fom the plants, such as vincristne, vinblastine, campthothecins, have been usedhave been used clinically for over 40 years. Numerous techniques have been developedto obtain compounds for drug discovery including isolation from plants, synthetic chemistry,screening bioassays. As part of efforts to discover phytochemicals as anticancer agent, ourgroup were isolated several compunds mainly from Annonaceae and Melliaceae family thatshowed active againts human leukemia HL-60 cells.</p
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Isolation of secondary metabolites from Annonaceae plants and their biological activities
Get PDF博士論文 (Doctoral dissertation)doctoral thesi
Isolation, identification and α-glucosidase inhibition evaluation of a phenolic compound from Elaeocarpus mastersii King leaves
No full textElaeocarpus mastersii King is an Indonesian folk medicine with high phenolic content. In this study, the E. mastersii King leaves were extracted using methanol solvent through maceration. The methanol extract was continuously fractionated by the liquid-liquid extraction using hexane, dichloromethane (DCM), and ethyl acetate solvents, respectively. The DCM fraction was purified by column chromatography using Silica gel 60 and Sephadex LH-20 as the stationary phase and monitored by thin-layer chromatography. This isolation process led to obtaining a pure compound with the appearance of white crystalline powder and a melting point of 198-199℃. This compound absorbed the UV light at the wavelength of 229 and 274 nm, as well as produced the bathochromic shift by the addition of NaOH reagent indicating the aromatic compound with the hydroxyl (OH) substituent. The IR spectrum confirmed the presence of aromatic and OH groups along with other functional groups, such as carbonyl (vmax 1693 cm-1) and alkane (C-H, vmax 2953 cm-1). The NMR data suggested the isolated compound as methyl gallate. Furthermore, the m/z value of the isolated compound was 185.04416 Da [M+H]+. It confirmed the monoisotopic mass of the methyl gallate (184.0362 Da). However, biological evaluation as an α-glucosidase inhibitor showed no positive activity
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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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