• Journal of Life Science
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• v.21 no.7
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• pp.1016-1024
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• 2011

The concentrations of bioactive material (polyphenolics and flavonoids) and the biological activities of antioxidative (DPPH [${\alpha},{\alpha}'$-diphenyl-${\beta}$-picrylhydrazyl] free radical scavenging activity, peroxidation of rat liver microsome, and Fe/Cu reducing power), ${\alpha}$-glucosidase inhibition, tyrosinase inhibition, and fibrinolytic activity were tested by in vitro experimental models using 70% methanolic extract from Ganoderma lucidum, Momordica charantia, Fagopyrum tataricum and their mixtures. The highest yield and the concentrations of polyphenolics and flavonoids were shown in the mixture extract. Mixture extract was shown to have the highest activities of ${\alpha}$-glucosidase inhibition and tyrosinase inhibition, fibrinolytic, DPPH free radical scavenging, and Fe/Cu reducing power in a concentration-dependent manner. From these results, mixture methanol extract was shown to have the most potent bioactive properties and to contain large amounts of biological materials such as polyphenolics and flavonoids. This mixture could be a good dietary supplement material candidate, such as for antidiabetic functional foods.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.2
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• pp.303-310
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• 2014

We show improved throughput scaling laws for an ultra-wide band (UWB) ad hoc network, in which n wireless nodes are randomly located. First, we consider the case where a modified hierarchical cooperation (HC) strategy is used. Then, in a dense network of unit area, our result indicates that the derived throughput scaling depends on the path-loss exponent ${\alpha}$ for certain operating regimes due to the power-limited characteristics. It also turns out that the HC protocol is dominant for 2 < ${\alpha}$ < 3 while using the nearest multihop (MH) routing leads to a higher throughput for ${\alpha}{\geq}3$. Second, the impact and benefits of infrastructure support are analyzed, where m base stations (BSs) are regularly placed in UWB networks. In this case, the derived throughput scaling depends on ${\alpha}$ due to the power-limited characteristics for all operating regimes. Furthermore, it is shown that the total throughput scales linearly with parameter m as m is larger than a certain level. Hence, the use of either HC or infrastructure is helpful in improving the throughput of UWB networks in some conditions.

• Journal of Applied Biological Chemistry
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• v.50 no.2
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• pp.70-73
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• 2007

Antioxidant and anti-diabetic activities of acorn were evaluated by its potential for scavenging stable DPPH free radical, inhibition of lipid peroxidation, reducing power, and inhibiton of ${\alpha}-glucosidase\;and\;{\alpha}-amylase$. The water extract of acorn exhibited strong antioxidant and antidiabetic related activities in the tested model systems. Solvent fractionation of the water extract revealed that the water fraction and the EtOAc fraction had strong antioxidant activity, and inhibitory activity on ${\alpha}-glucosidase\;and\;{\alpha}-amylase$. The water fraction exhibited higher DPPH radical scavenging activity ($EC_{50}=7.19{\mu}g/mL$) than that of ${\alpha}-tocopherol\;(EC_{50}=7.59{\mu}g/mL)$. It is considered that water extract of acorn has the potential for natural antioxidant and anti-diabetic products.

• Journal of the Korean Applied Science and Technology
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• v.6 no.2
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• pp.53-58
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• 1989

A series of four sodium ${\alpha}-sulfo$ fatty acid allylester oligomers such as sodium ${\alpha}-sulfo$ lauric acid allylester oligomer, sodium ${\alpha}-sulfo$ myristic acid allyl ester oligomer, sodium ${\alpha}-sulfo$ palmitic acid allyl ester oligomer and sodum ${\alpha}-sulfo$ stearic acid allyl ester oligomer were examined for surface tension, defloculation effect and emulsifying power. Also critical micelle concentration (cmc) was evaluated. Consequently, these sodium allyl ${\alpha}-sulfo$ aliphatic carboxylate aligomers show o/w type emulsifying agent and dispersion effect in 1g/100ml soulution.

• Korean Journal of Acupuncture
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• v.20 no.3
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• pp.9-27
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• 2003

Objectives : The aim of this study was to examine the effects of electro-acupuncture(EA) at the SP6(Sameumgyo)-GB39(Hyeonjong) on normal human EEG using power spectral analysis. Methods : EEG power spectrum exhibit site-specific and state-related differences in specific frequency bands. In this study, power spectrum was used as a measure of complexity(LAXTHA Co., KOREA). 30 channel EEG study was carried out in 20 subjects $(20\;males;\;age=21.4{\pm}0.5\;years)$. Results : In $\alpha$(alpha) band, the power values at F4 channels(p<0.05) during the SP6-GB39 acupoints treatment was significantly increased. But, the power values at Fz channel during the non-acupoint treatment was significantly decreased . In $\beta$(beta) band, the power values at Fz, FTC1, T3 channels(p<0.05) was significantly increased during the SP6-GB39 acupoints treatment. In $\delta$(delta) band, the power values at F4, C3, Cz, CP1, Pz channels(p<0.05) during SP6-GB39 acupoints treatment were significantly decreased.

• Korean Journal of Food Science and Technology
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• v.42 no.5
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• pp.598-604
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• 2010

Electron donating ability (EDA), reducing power, total phenolic contents, total flavonoid contents, antimicrobial activity, and ${\alpha}$-glucosidase inhibitory effects of twenty-two sorghum varieties were examined using ethanol extracts (70%, v/v). The electron donationg abilities (EDA) of Mesusu and Bulgeunjangmoksusu (94% at 10 ${\mu}g$/mL) indicated higher antioxidant activity compared to those of other varieties and standard antioxidants such as BHT (13%) and BHA (74%). The reducing power of Mesusu ($OD_{700}$=0.71) suggested higher antioxidant activity, which was dependent on sample concentration. Bitjarususu showed the highest content of total phenolics (22.9 mg GAE/g); however, extracts from Heuinsusu exhibited the lowest content of total phenolics (16.4 mg GAE/g). Jangmoksusu showed the highest total flavonolic contents (3.5 mg QE/g), and Sigyeongsusu and Chal (GS) susu displayed the most antibacterial activity (MIC=8 ${\mu}g$/mL) against Escherichia coli. Extracts of Bulgeunjangmoksusu, Moktaksusu, and Ginjangmoksusu showed the highest ${\alpha}$-glucosidase inhibitory effect (98%) at the concentration of 5 ${\mu}g$/mL.

• Proceedings of the Optical Society of Korea Conference
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• 1996.09a
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• pp.96-96
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• 1996

• Korean Journal of Psychosomatic Medicine
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• v.25 no.1
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• pp.63-72
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• 2017

Objectives : Attention-deficit hyperactivity disorder(ADHD) is characterized by significant impairments in executive functions, with a prevalence of approximately 3-5% of all children worldwide. The goal of this study was to examine the relationship between executive functions and electrophysiological activities in children and adolescents with ADHD. Methods : In 31 patients with ADHD, resting-state EEG was recorded, and Comprehensive Attention Test(CAT), Stroop Color-Word Inference Test(Stroop CWIT), Trail Making Test(TMT), and Wisconsin Card Sorting Test(CST) were administered. Korean version of the ADHD Rating Scale(K-ARS) was assessed. Results : Alpha and beta power positively correlated with the Attention Quotient(AQ), while delta power negatively correlated with AQ from CAT. In the Stroop CWIT, decreased delta power and increased beta power were related to higher performance. Power of the alpha band increased with higher TMT performance. Moreover, delta power negatively correlated with good performance on the CST, while alpha and high gamma band showed a positive correlation. Correlation with the parent-rating of ADHD symptoms showed a negative correlation between alpha power and higher scores on the K-ARS. Conclusions : These findings indicate that relative power in higher frequency bands of EEG is related to the higher executive function in children and adolescents with ADHD, while the association with the relative power in lower frequency bands of EEG seem to be vice versa. Furthermore, the findings suggest that QEEG may be a useful adjunctive tool in assessing patients with ADHD.

• Journal of the Korean Applied Science and Technology
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• v.15 no.3
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• pp.39-45
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• 1998

In recent years, there has been considerable interest in the development of new functional surfactant including new type of anionic surfactants. Anionic surfactants, ${\alpha}-sulfo$ fatty acids that straight long chain alkyl group having from 12 to 18 carbon atoms, were synthesized with sulfur trioxide-dioxane complex to good yield. Xylitol ${\alpha}-sulfo$ fatty acid esters were obtained by reaction that the acetification and esterification of xylitol, by addition reaction with sodium chloride and hydrolysis respectively. These compounds were a new group of destructible surfactants which readily hydrolyzed and oxidized in natural water reservoirs. Physical properties of these new compounds involved surface tension, critical micelle concentration(cmc), foaming power, emulsion power, and hydrolysis properties, were measured. The cmc values of the compounds by ring method were assumed to $7.0{\times}10^{-3}{\sim}3.0{\times}10^{-2}mol/{\ell}$ range and surface tensions at cmc were $25{\sim}31dyne/cm$ respectively.

• Korean Journal of Acupuncture
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• v.36 no.4
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• pp.241-251
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• 2019

Objectives : The purpose of this study was to examine the effects of electroacupuncture at GB14, on brain activity assessed on an electroencephalogram(EEG). Methods : (1) Thirty-four healthy participants were randomly divided into two groups, receiving either real acupuncture or non-penetrating sham acupuncture at GB14. (2) EEG measurements were conducted simultaneously before and after a 5-minute electroacupuncture stimulation, and the differences in the resulting EEG parameters were compared between the test and control groups. Results : (1) Absolute power increased significantly in the theta-wave channel of the occipital region and in the entire alpha-wave channel. (2) Relative power decreased significantly in the theta-wave channels of the frontal and occipital regions. (3) Coherence decreased significantly in the theta- and beta-wave channels of the parietal and occipital regions, and increased significantly in the alpha-wave channels of most areas. Conclusions : This study shows that electroacupuncture stimulation at GB14 activates the alpha frequency band in particular.