1,720,955 research outputs found
Isolation of Stigmasterol and Β-Sitosterol From Ethyl Acetate Extracts of Musa Acuminata Colla Bract
Full text linkThe research focuses on uncovering the bioactive chemicals or compounds in the banana bloom by isolating secondary metabolites. The researchers used column chromatography to isolate the compounds from the ethyl acetate extract. The BFB 57 fractions were obtained as a white needle-like crystal compound after being recovered from the column and put via thin-layer chromatography to verify their purity for component separation. 1D nuclear magnetic resonance (1D NMR) and 2D nuclear magnetic resonance (2D NMR) spectroscopy were used to characterize the fraction. By carefully analysing the NMR spectral data and comparing the measured NMR spectral data with those found in the literature, the structures of the separated compounds were determined to reveal stigmasterol and β-sitostero
Overview of Importance and Isolation of Β-Sitosterol From Ethyl Acetate Extracts of Musa Acuminata Calla (Banana Blossom)
Full text linkIn northern Nigeria, the banana blossom has traditionally been used to treat a variety of ailments, including microbiological infections; it reduces menstrual bleeding, aids in the treatment of diabetes, anaemia, and ulcers, reduces anxiety, aids in weight loss, and produces an undetermined amount of filtrate decoction to facilitate conception. As a result, the study intends to isolate secondary metabolites to identify the bioactive compound(s) found in banana blossoms. The ethyl acetate extract was utilised in column chromatography to isolate the compound. Fractions were collected from the column and subjected to thin-layer chromatography to confirm their purity for component separation using a thin stationary phase supported by an inert backing, yielding BF58 fractions. Researchers characterised the fraction BF 58 using NMR spectroscopy. β-Sitosterol was isolated from Musa acuminata calla
Cycloeucalenone Isolation and Characterisation from Musa Acuminata Colla
Full text linkThe isolation and characterisation of bioactive compound(s) from Musa acuminata colla (banana blossom) as a result, the research aimed to isolate secondary metabolites. Sample Extraction was carried out using the maceration method to obtain ethyl acetate extracts. The Ethyl acetate extract of the Banana blossom flower and bract was used for isolation. Compounds isolation using Column Chromatography, the 260 fractions from the column are subjected to TLC testing to see the separation of the component combination by applying a thin stationary phase supported by an inert backing that yields 30 fractions. The purpose of TLC is to obtain well-defined, well-separated spots. Each component has a retention factor (RF), which combines fractions with the same RF value. The four fractions obtained from TLC activities were analysed using NMR spectroscopy (FT-IR, 1D NMR, 2D NMR and Mass spec), which resulted in the isolation of triterpenes compounds named Cycloeucalenone
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
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
- …
