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Hsu Y.-W.,Chung Shan Medical University | Tsai C.-F.,Trans World University | Chen W.-K.,Chung Shan Medical University | Chen W.-K.,National Tainan Institute of Nursing | And 2 more authors.
Food Chemistry | Year: 2011

Lutein and zeaxanthin were extracted from daylily (Hemerocallis disticha) flowers using supercritical fluid extraction-carbon dioxide (SFE-CO2) at a temperature range of 50-95 °C and pressure range of 300-600 bar. The extracts were analysed by HPLC with a C30 column and an isocratic solvent system: methanol/methyl-tert-butyl ether = 86/14 (v/v). Moreover, the antioxidant capacities of the extracts were evaluated by a 2,2-diphenyl-2- picrylhydrazyl radical scavenging assay and a chemiluminescence assay to measure the scavenging activity of hydrogen peroxide, superoxide anion and hydroxyl radical. The optimal lutein and zeaxanthin extraction could be achieved at 80 °C and 600 bar, and the extraction pressure was the most important parameter for SFE-CO2. In addition, the extracts had significantly higher antioxidant activities in all antioxidant assays. © 2011 Elsevier Ltd. All rights reserved. Source

Hsu J.-W.,National Tainan Institute of Nursing | Huang D.-W.,Chung Yuan Christian University
Physica A: Statistical Mechanics and its Applications | Year: 2012

The Impact Factor has become a well-known measure of the average citation number of articles published in a scientific journal. A journal with a high Impact Factor is assumed to have a low percentage of uncited articles. We show that the scaling relation between the Impact Factor and the uncited percentage can be understood by a simple mechanism. The empirical data can be reproduced by a random mechanism with the cumulative advantage. To further explore the robustness of such a mechanism, we investigate the relation between the average citation number and the uncited percentage from different perspectives. We apply the idea of Impact Factor to the publications of an institute in addition to its general application to the publications of a journal. We find that the same scaling relation can be obtained. We also show that a static relation can be applied to describe the time evolution of a dynamical process. These results provide further justification for the same citation mechanism behind different research fields. © 2011 Elsevier B.V. All rights reserved. Source

Hsu Y.-W.,Chung Shan Medical University | Tsai C.-F.,TransWorld University | Chen W.-K.,National Tainan Institute of Nursing | Huang C.-F.,Chia Medical University | Yen C.-C.,Chung Shan Medical University
Food and Chemical Toxicology | Year: 2011

Green tea is believed to be beneficial to health because it possesses antioxidant, antiviral and anticancer properties. The potential toxicity of green tea when administered at high doses via concentrated extracts, however, has not been completely investigated. The objective of the present study was to evaluate the safety of green tea extract in ICR mice using a subacute exposure paradigm. In this study, mice were orally administered (gavage) green tea extract at doses of 0 (as normal group), 625, 1250 and 2500. mg/kg. body weight/day for 28. days. The results showed that oral administration of green tea extract did not cause adverse effects on body weight, organ weights, hematology, serum biochemistry, urinalysis or histopathology. Additionally, administering green tea extract via gavage significantly reduced triglyceride and cholesterol levels. These observed effects could be attributed to the high levels of catechins present in green tea as these compounds have been reported to have beneficial health effects. The no-observed-adverse-effect level for green tea extract derived from the results of the present study was 2500. mg/kg. body weight/day. © 2011 Elsevier Ltd. Source

Hsu J.-W.,National Tainan Institute of Nursing | Huang D.-W.,Chung Yuan Christian University
Computer Physics Communications | Year: 2011

We study the citation dynamics of scientific publications over the years. We propose a simple cellular automaton model featuring a combination of two distinct mechanisms, i.e. the random assignment and the preferential attachment, to investigate the dynamics of journal citation. Different from most previous studies focusing on highly cited papers, we analyze the time evolution of the entire citation distribution. Empirical data can be well reproduced by numerical simulations. Within the linear regime of the Cited Half-Life, a steady accumulation of citations can be expected. Moreover, within this linear regime, the ratio between the above two mechanisms is a constant. Besides the average citation represented by the Impact Factor, such a constant ratio can also be a characteristic of the journal. © 2010 Elsevier B.V. All rights reserved. Source

Hsu J.,National Tainan Institute of Nursing | Huang D.,Chung Yuan Christian University
Scientometrics | Year: 2011

We obtained data of statistical significance to verify the intuitive impression that collaboration leads to higher impact. We selected eight scientific journals to analyze the correlations between the number of citations and the number of coauthors. For different journals, the single-authored articles always contained the lowest citations. The citations to those articles with fewer than five coauthors are lower than the average citations of the journal. We also provided a simple measurement to the value of authorship with regards to the increase number of citations. Compared to the citation distribution, similar but smaller fluctuations appeared in the coauthor distribution. Around 70% of the citations were accumulated in 30% of the papers, while 60% of the coauthors appeared in 40% of the papers. We find that predicting the citation number from the coauthor number can be more reliable than predicting the coauthor number from the citation number. For both citation distribution and coauthor distribution, the standard deviation is larger than the average value. We caution the use of such an unrepresentative average value. The average value can be biased significantly by extreme minority, and might not reflect the majority. © 2010 Akadémiai Kiadó, Budapest, Hungary. Source

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