• Journal of Microbiology and Biotechnology
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• v.6 no.2
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• pp.98-102
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• 1996

A thermostable tyrosine phenol-lyase gene of a thermophilic Symbiobacterium species was cloned and overexpressed in Escherichia coli in order to produce the biocatalyst for the synthesis of 3, 4-dihy-droxyphenyl-L-alanine (L-DOPA). The substrates used for the synthetic reaction were pyrocatechol, so-dium pyruvate, and ammonium chloride. The enzyme was stable up to $60^{\circ}C$, and the optimal temperature for the synthesis of L-DOPA was $37^{\circ}C$ . The optimal pH of the reaction was about 8.3. Enzyme activity was highly dependent on the amount of ammonium chloride and the optimal concentration was estimated to be 0.6 M. In the case of pyrocatechol, an inactivation of enzyme activity was observed at con-centrations higher than 0.1 M. Enzyme activity was increased by the presence of ethanol. Under op-timized conditions, L-DOPA production was carried out adding pyrocatechol and sodium pyruvate to the reaction solution intermittently to avoid substrate depletion during the reaction. The concentration of L-DOPA reached 29.8 g/l after 6 h, but the concentration didn t increase further because of the formation of byproducts by a non-enzymatic reaction between L-DOPA and pyruvate.

• Journal of Ginseng Research
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• v.10 no.1
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• pp.94-100
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• 1986

Korean red ginseng tails was extracted with solutions having various ethanol concentration at the temperature range of 70-$100^{\circ}C$, Extraction was carried out for 1-5 times of 8 hours at given condition. Sensory properties and color of RG-Ext. were found to be significantly affected by conditions of extraction. Absorbance at 490nm was decreased as the ethanol concentration increased, the increase in ethanol concentration also showed an increase in the Hunter's values of "L" and "b", and a decrease in "a" value indicating the color of RG-Ext. was changed to yellowish with less in darkness. Increase in extraction time and temperature caused darker brown color which is indicates a typical phenomena of non-enzymatic browning reaction. The flavor and bitternes of RG-Ext. were found to be significantly increased as the ethanol concentration increase, the generally responses of acceptance range of ethanol concentration was 30-70%.

• The Journal of Korean Physical Therapy
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• v.20 no.3
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• pp.53-59
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• 2008

Purpose: The non-receptor-type protein tyrosine kinase Syk (636 amino acids, 72 kDa) is ubiquitously expressed in hematopoietic stem cells and has been widely studied as a regulator and effector of B cell receptor signaling that occurs in processes such as differentiation, proliferation and apoptosis. However, the mechanism relating Syk and p38 mitogen-activated protein kinases (p38MAPK) by endothelin-1 (ET-1, 21 amino acids) stimulation in muscle cells, especially in the volume-dependent hypertensive state, remains unclear. Methods: In this study, we investigated the relationship between Syk and p38MAPK for isometric contraction and enzymatic activity by ET-1 from rat aortic smooth muscle cells and aldosterone-analogue deoxycorticosterone acetate (DOCA) hypertensive state rats (ADHR). Results: The systolic blood pressure was significantly increased in ADHR than in a control group of animals. ET-1 induced isometric contraction and phosphorylation of p38MAPK, which was increased in muscle strips from ADHR. Increased vasoconstriction and phosphorylation of p38MAPK induced by treatment with 30 nM ET-1 were inhibited by the use of 10${\mu}M$ SB203580, an inhibitor of p38MAPK from ADHR. Furthermore, ET-1 induced isometric contraction and phosphorylation of Syk and p38MAPK, which were increased in the aortic smooth muscle cells. Increased tension and phosphorylation of Syk and p38MAPK induced by ET-1 were inhibited by SB203580 from rat aortic smooth muscle cells. Conclusion: These results, suggest that the Syk activity affects ET-1-induced contraction through p38MAPK in smooth muscle cells and that the same pathway directly or indirectly is associated with volume dependent hypertension. The findings suggest the need to develop cardiovascular disease-specialized physical therapy.

• Journal of the Korean Electrochemical Society
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• v.17 no.2
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• pp.130-137
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• 2014

A strip sensor based on $PbO_2$/carbon paste electrode was prepared by a screen-printing method, and employed to electrochemically determine the concentration of fruit sweeteners(i.e. glucose, sucrose, and fructose). The $PbO_2$/carbon paste electrode could monitor electrocatalytic oxidation of organic compounds such as carbohydrates, and measure the levels of natural sweeteners without enzyme. Severe interference from ascorbic acid was effectively reduced by modifying the electrode surface with a Nafion membrane. The response level of the Nafion/$PbO_2$/carbon paste electrode increased in the order of fructose, sucrose, and glucose, which corresponds to the order of sweetness perceived by humans.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.3
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• pp.413-418
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• 2018

In this paper, we describe the development of a non-enzymatic glucose sensor based on copper nanocubes(Cu NCs) electroplated laser induced graphene(LIG) electrodes which can detect a certain range of glucose concentrations. $CO_2$ laser equipment was used to form LIG electrodes on the PI film. This fabrication method allows easy control of the LIG electrode size and shape. The Cu NCs were electrochemically deposited on the LIG electrodes to improve electron transfer rates and thus enhancing electrocatalytic reaction with glucose. The average sheet resistances before and after electroplating were $15.6{\Omega}/{\Box}$ and $19.6{\Omega}/{\Box}$, respectively, which confirmed that copper nanocubes were formed on the laser induced graphene electrodes. The prepared electrode was used to measure the current according to glucose concentration using an electrochemical method. The LIG electrodes with Cu NCs demonstrated a high degree of sensitivity ($1643.31{\mu}A/mM{\cdot}cm^2$), good stability with a linear response to glucose ranging from 0.05 mM to 1 mM concentration, and a limit of detection of 0.05 mM. In order to verify that these electrodes can be used as flexible devices, the electrodes were bent to $30^{\circ}$, $90^{\circ}$, and $180^{\circ}$ and cyclic voltammetry measurements were taken while the electrodes were bent. The measured data showed that the peak voltage was almost constant at 0.42 V and the signal was stable even in the flexed condition. Therefore, it is concluded that these electrodes can be used in flexible sensors for detecting glucose in the physiological sample like saliva, tear or sweat.

• Food Science of Animal Resources
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• v.38 no.1
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• pp.135-142
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• 2018

Recently, research on the processing of raw functional materials with the aim of improving various physiological activities has been conducted. In this study, we investigated the antioxidant activity of royal jelly (RJ) hydrolysates obtained from three commercial proteases. Enzyme-treated royal jelly (ERJ), in which the RJ hydrolysates were converted into easy-to-absorb shorter chain monomers through the removal of two known allergen proteins, showed no difference in the content of (E)-10-hydroxydec-2-enoicacid (10-HDA) or the freshness parameter and showed a significant increase in total free amino acid content. The antioxidant activity of ERJ was determined by 1,1-diphenyl-2-picrylhydrazyl (DPPH) and chemical assays. The ERJ showed about 80% DPPH-radical scavenging activity at same concentration of ascorbic acid. The antioxidant effect of ERJ was confirmed to be due to reduction of intracellular reactive oxidative species (ROS) and nitric oxide (NO) production in LPS-treated macrophages. Moreover, ERJ significantly increased the activity of the antioxidant enzyme superoxide dismutase (SOD) and the level of the antioxidant glutathione (GSH) in a dose-dependent manner. Interestingly, these antioxidant activities of ERJ were stronger than those of non-treated RJ. These findings indicate that ERJ has high potential as an antioxidant agent for use in human and animal diets.

• Food Science of Animal Resources
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• v.38 no.1
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• pp.78-87
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• 2018

This study aimed to research the possibilities of using retrograded flour produced in the laboratory environment in meatballs and the characteristics of these meatballs. In the use of retrograded flour to produce meatballs, it was ensured that the meatball properties, with respect to chemical, physical and sensorial aspects, were comparable to those of meatballs produced with bread (traditional) and rusk flour (commercial). The cooking loss of meatballs produced with using retrograded flour was similar to that of commercial meatballs. Doses of retrograded flour from 5% to 20% led to a significant decrease in cooking loss, from 21.95% to 6.19%, and in the diameter of meatballs, from 18.60% to 12.74%, but to an increase in the thickness of meatballs, from 28.82% to 41.39% compared to the control. The increase of $a^*$ and $b^*$ values was shown in that the meatballs were browned on cooking with increasing retrograded flour doses because of non-enzymatic reactions. The springiness of the traditional meatballs was significantly higher than that of the other meatballs. This might have been due to the bread crumbs having a naturally springy structure. Moreover, the addition of retrograded flour in the meatballs significantly (p<0.05) affected the hardness, springiness and cohesiveness of the meatballs with respect to textural properties. Accordingly, it is considered that the use of 10% retrograded flour is ideal to improve the sensorial values of meatballs and the properties of their structure.

• Preventive Nutrition and Food Science
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• v.22 no.3
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• pp.184-190
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• 2017

Matrix metalloproteinases (MMPs) are endopeptidases that take significant roles in extracellular matrix degradation and therefore linked to several complications such as metastasis of cancer progression, oxidative stress, and hepatic fibrosis. Hizikia fusiformis, a brown algae, was reported to possess bioactivities, including but not limited to, antiviral, antimicrobial, and anti-inflammatory partly due to bioactive polysaccharide contents. In this study, the potential of H. fusiformis against cancer cell invasion was evaluated through the MMP inhibitory effect in HT1080 fibrosarcoma cells in vitro. H. fusiformis crude extract was fractionated with organic solvents, $H_2O$, n-BuOH, 85% aqueous MeOH, and n-hexane (n-Hex). The non-toxicity of the fractions was confirmed by MTT assay. All fractions inhibited the enzymatic activities of MMP-2 and MMP-9 according to the gelatin zymography assay. Cell migration was also significantly inhibited by the n-Hex fraction. In addition, both gene and protein expressions of MMP-2 and -9, and tissue inhibitor of MMPs (TIMPs) were evaluated by reverse transcription-polymerase chain reaction and Western blotting, respectively. The fractions suppressed the mRNA and protein levels of MMP-2, MMP-9 while elevating the TIMP-1 and TIMP-2, with the $H_2O$ fraction being the least effective while n-Hex fraction the most. Collectively, the n-Hex fraction from brown algae H. fusiformis could be a potential inhibitor of MMPs, suggesting the presence of various derivatives of polysaccharides in high amounts.

• Korean Journal of Plant Resources
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• v.14 no.2
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• pp.116-123
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• 2001

The non-enzymatic antioxidants and antioxidant enzyme from the extracts of Parthenocissus tricuspidata PLANCH. were examined in order to utilize natural product for cerchemopreventive agents. The antioxidant potential and enzyme activities on plant positions in the extracts of Parthenocisuss tricuspidata PLANCH. showed considerable differences. The antioxidant activity of the leaf extracts by Ethyl acetate fractions of Parthenocisuss tricuspidata PLANCH. was the highest among three positions ($7.57\mu\textrm{g}/m\ell$). The highest activities showed in S-5 (in leaf), S-4 (in stem) and S-3 (in root) fraction by Silicagel column chromatography and the antioxidant activity showed, in purified extract of each positions, $7.06\mu\textrm{g}/m\ell$ (in leaf), $6.99\mu\textrm{g}/m\ell$ (in stem) and $12.39\mu\textrm{g}/m\ell$ (in root) respectively. The activities of DPPH by LH-20 column chromatography revealed much higher than those by silica-gel column chromatography. These were identified as the phenolic compounds known as antioxidant compounds such as Benzoic acid(Gallic acid), 1-methyl-3-(2-phenylethen) benzene, phloroglucinol and 1,2-dihydroxy-4-(1-propyl)benzene by GC/MS. POD activities in the stem and root were higher than in the leaf. SOD activity was highest in the leaf, stem and root activity was comparatively low. Especially, SOD activity in leaf was over 2 times higher than root.

• Food Science and Preservation
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• v.12 no.6
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• pp.608-612
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• 2005

Fourier transform-near infrared (FT-NIR) spectroscopy is a simple, rapid, non-destructive technique which can be used to make quantitative analysis of chemical composition in grain. An interest in total dietary fiber (TDF) of grain such as rice has been increased due to its beneficial effects for health. Since measuring methods for TDF content were highly depending on experimental technique and time consumptions, the application of FT-NIR spectroscopy to determine TDF content in milled rice. Results of enzymatic-gravimetric method were $1.17-1.92\%$ Partial least square (PLS) regression on raw NIR spectra to predict TDF content was developed Accuracy of prediction model for TDF content was certified for regression coefficient (r), standard error of estimation (SEE) and standard error of prediction (SEP). The r, SEE and SEP were 0.9705, 0.0464, and 0.0604, respectively. The results indicated that FT-NIR techniques could be very useful in the food industry and rice processing complex for determination of TDF in milled rice on real time analysis.