1,720,958 research outputs found
Effect of ethanol solvent concentrations in pepino melon fruit (Solanum muricatum Aiton) extraction on total flavonoid, phenolic, and β-carotene content
Full text linkThe quality of an extract is determined by the type and level of compounds contained therein. The
solvent is one of the elements that influences the extract's quality. Therefore, extraction must be
carried out using a solvent that can extract bioactive substances. This study was aimed at obtaining the
optimal concentration of ethanol in extracting flavonoids, phenolics, and β-carotene from pepino
melon fruit. In this study, dried pepino melon fruit was extracted using ethanol of 50%, 70%, and 96%.
The extracts were analyzed qualitatively for phenolic and flavonoid using thin layer chromatography
(TLC), and quantitatively using a spectrophotometry. Meanwhile, β-carotene levels were determined
using high pressure liquid chromatography (HPLC). The data of level flavonoid, phenolic, and β-
carotene were statistically analyzed using multivariate analysis of variance. The results showed that
50%, 70%, and 96% ethanol solvent produced extracts with a yield value of 51.8%; 87.4%; 54.6%;
total flavonoid content of 0.298 ± 0.04 mgQE/g; 0.559 ± 0.03 mgQE/g; 0.289 ± 0.01 mgQE/g; total
phenolic content of 4.763 ± 0.08 mgGAE/g; 3.631 ± 0.12 mgGAE/g; 3.317 ± 0.10 mgGAE/g; β-
carotene level of 0.157 ± 0.02 mg/g; 0.910 ± 0.16 mg/g; 1.054 ± 0.13 mg/g, respectively. The
statistical analysis showed that there was a significant difference in different ethanol concentrations in
extraction with the content of total flavonoids, total phenolics, and β-carotene (p<0.05). The optimal
ethanol solvent for extracting flavonoids, phenolic compounds, and β-carotene from pepino melon
fruit was 70% ethanol
Efektivitas Ekstrak Daun Kakao (Theobroma cacao L.) Sebagai Penumbuh Rambut Kelinci New Zealand White
Full text linkKerontokan rambut merupakan ciri rambut tidak sehat yang disebabkan oleh paparan terik sinar matahari, zat kimia pewarna rambut, dan faktor hormonal. Hair tonic merupakan sediaan rambut yang dapat menjaga kesehatan rambut. Tujuan penelitian ini untuk mengetahui aktivitas pertumbuhan rambut ekstrak etanol daun kakao dalam sediaan hair tonic dengan perbedaan konsentrasi ektrak serta keamanannya. Uji aktivitas pertumbuhan rambut dilakukan dengan mengoleskan sediaan pada punggung kelinci dengan parameter pengukuran panjang rambut pada minggu ke-1, 2 dan 3 dan bobot rambut pada minggu ke-3. Uji keamanan dilakukan dengan uji iritasi kulit yang diamati pada jam ke- 24 dan 48. Data yang diperoleh dari hasil uji kemudian dilakukan analisis data menggunakan SPPS 22. Hasil penelitian menunjukkan bahwa sediaan hair tonic yang mengandung ekstrak etanol daun kakao dengan konsentrasi 15% memiliki efektivitas yang lebih tinggi dalam merangsang pertumbuhan rambut dibandingkan dengan kontrol positif berupa minoxidil 2%. Hasil uji iritasi kulit pada kelinci menunjukkan tidak adanya eritema ataupun edema. Dapat disimpulkan bahwa ekstrak etanol daun kakao dapat diformulasikan sebagai sediaan hair tonic yang memenuhi syarat fisik serta aman digunakan pada kulit
Penetapan Kadar β-Karoten Tanaman Krokot(Portulaca oleracea) dan Wortel (Daucus carota L.) Secara Spektrofotometri UV-Vis
No full textSenyawa β-karoten merupakan provitamin A yang mempunyai peranan penting dalam pembentukan vitamin A. Vitamin A merupakan vitamin yang sangat dibutuhkan manusia, terutama untuk pertumbuhan dan perkembangan serta penglihatan mata manusia. Telah diketahui bahwa wortel dan krokot mengandung β-karoten yang dibutuhkan tubuh untuk menekan efek dari paparan radikal bebas atau sebagai antioksidan. Tujuan dilakukannya penelitian untuk mengetahui perbandingan kadar β-karoten yang terkandung dalam wortel dan krokot menggunakan metode Spektrofotometri UV-Vis. Penelitian ini dilakukan secara kualitatif yaitu dengan uji warna antimon triklorida dan uji KLT, pengukuran kuantitatif dilakukan dengan Spektrofotometri UV-Vis. Hasil KLT diperoleh nilai Rf antara pembanding dan wortel yang mempunyai nilai sama yaitu sebesar 0,93, serta nilai Rf antara pembanding dan krokot juga sama yaitu sebesar 0,95. Hasil kadar β-karoten yang diperoleh pada ekstrak wortel sebesar 2,40 mg/gram ± 0,02% dan pada ekstrak krokot sebesar 6,91 mg/gram ± 0,25%. Hasil dari penelitian tersebut dapat disimpulkan bahwa kandungan β-karoten pada krokot lebih tinggi dibandingkan wortel. Hasil analisis data menggunakan uji t independen (SPSS) menunjukkan adanya perbedaan yang signifikan antara sampel krokot dan wortel (P0,05)
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
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