• The Transactions of the Korean Institute of Electrical Engineers C
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• v.52 no.8
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• pp.365-370
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• 2003

This research aims to develop an indicator-free DNA chip using micro-fabrication technology. At first, we fabricated a DNA microarray by lithography technology. Several probe DNAs consisting of thiol group at their 5-end were immobilized on the gold electrodes. Then indicator-free target DNA was hybridized by an electrical force and measured electrochemically in potassium ferricyanide solution. Redox peak of cyclic-voltammogram showed a difference between target DNA and mismatched DNA in an anodic peak current. Therefore, it is able to detect various genes electrochemically after immobilization of various probe DNAs and hybridization of indicator-free DNA on the electrodes simultaneously It suggested that this DNA chip could recognize the sequence specific genes.

• Korean Chemical Engineering Research
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• v.55 no.1
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• pp.27-33
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• 2017

The determination of disulfide bonds is important for comprehensive understanding of the chemical structure of protein. So far, many strategies for the disulfide bond analysis have been suggested in terms of speed and sensitivity. However, most of these strategies have not considered free thiol residues in the target protein in the process of determining the disulfide bond. We suggested the strategy which was composed of four steps for the identification of disulfide bonds; the first step was the prediction of possible disulfide bonds, the second step was the determination of free cysteine residues, the third step was the analysis of disulfide bond using a high-resolution mass spectrometry, and the final step was the determination of disulfide bonds based on the comprehensive verification. In this study, we performed the characterization of disulfide bonds for the recombinant protein (HRPE1), where 1 and 5 inter- and intra-chain disulfide bonds were identified, respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.05a
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• pp.71-73
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• 2006

This research aims to develop a multiple channel electrochemical DNA chip using micro- fabrication technology. At first, we fabricated a high integrated type DNA chip array by lithography technology. Several probe DNAs consisting of thiol group at their 5-end were immobilized on the gold electrodes. Then target DNAs were hybridized by an electrical force. Redox peak of cyclic-voltammogram showed a difference between target DNA and mismatched DNA in the anodic peak current. Therefore. it is able to detect a various genes electrochemically after immobilization of a various probe DNA and hybridization of label-free DNA on the electrodes simultaneously. It suggested that this DNA chip could recognize the sequence specific genes.

• The Korean Journal of Food And Nutrition
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• v.7 no.3
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• pp.232-238
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• 1994

Adriamycin is a major cancer chemotherapeutic agent against a me range of human neoplasms. However, its clinical application is limited since It has a variety of side effects, bone marrow suppression and cardiotoxity, and this toxicity appears by free radical. This study investigated the effect of Ampelopsis radix on the toxicity of adriamycin. The methanol fraction reduced slightly adriamycin induced lipid peroxidation and superoxide production at the dose of 50mg /kg. 1.p., respectively. During the adriamycin administration. Protein bound-SH, nonprotein bound-SH, and glutathione-5-transferase did not change, but methanol fraction treated group were markedly increase. These results indicated that Ampelopsis radix has a major influence on the thiol group and related enzyme activity on the antioxidative effects.

• Food Science of Animal Resources
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• v.42 no.5
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• pp.816-832
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• 2022

To evaluate the effects of early postmortem vacuum packaging (VP) on meat quality during postmortem chilled storage, hot-boned lamb was vacuum-packaged at 1, 6, 12, 24, and 48 h postmortem and stored around 2℃ until 168 h postmortem, with lamb packaged in plastic wrap as the control (aerobic packaging). Intramuscular pH decline was delayed when lamb was vacuum packaged at 1, 6, and 12 h postmortem (p<0.05). The lamb vacuum-packaged at 1 h postmortem (VP-1h group) had significantly lower shear force values and purge losses accompanied by lower free thiol group values than other treatments during postmortem storage and was also higher in extractable calpain-1 activity by 6 h postmortem (p<0.05). Free thiol group concentrations were significantly higher after VP at 6 and 12 h postmortem (p<0.05). Packaging lamb under vacuum very early postmortem produced the lowest shear force and purge loss, likely by slowing heat loss and muscle temperature decline, implying that lamb quality is improved by VP when applied very early postmortem. This was at the expense of protein oxidation, which was unrelated to other meat quality measurements, most likely because potential contracture during hot boning confounded its impact. Further research is required to understand the implications of the interaction between protein oxidation, VP, and hot boning on the acceptability of lamb.

• Proceedings of the KIEE Conference
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• 2002.11a
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• pp.51-53
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• 2002

This research aims to develop a multiple channel electrochemical DNA chip using micro-fabrication technology. At first, we fabricated a high integrated type DNA chip array by lithography technology. Several probe DNAs consisting of thiol group at their 5-end were immobilized on the sold electrodes. Then target DNAs were hybridized by an electrical force. Redox peak of cyclic-voltammogram showed a difference between target DNA and mismatched DNA in the anodic peak current. Therefore, it is able to detect a various genes electrochemically after immobilization of a various probe DNA and hybridization of label-free DNA on the electrodes simultaneously. It suggested that this DNA chip could recognize the sequence specific genes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.3
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• pp.603-608
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• 2004

Traditional Jeju tofu with a hard texture was manufactured by traditional method with a compounded coagulant. The processing condition for industrial production was optimized by determining soaking of soybean, extraction and heat treatment of soymilk as well as concentration and composition of coagulant. Maximum yield of soymilk was obtained by grinding one part of soaked soybean with eight parts of water, and the soluble solid of soymilk was about 8$^{\circ}$Brix. The free thiol group in soymilk was maximally exposed by heating at 10$0^{\circ}C$ for 2 min. A vacuum cooker for heating soymilk was effective for the improvement of yield and texture properties of tofu. The hardness of traditional Jeju tofu was obtained by increasing pressing time and drying by a fan instead of soaking in cold water. Optimization of a traditional tofu production resulted in the increase of total yield and improvement of quality control. Texture of traditional Jeju tofu prepared in industrial production scale was analyzed by instrumental analysis and sensory evaluation. Traditional Jeju tofu showed higher score in the hardness, roasting taste and overall preference compared with a commercial tofu, showing significant difference in 5% significant level..

• The Journal of the Acoustical Society of Korea
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• v.35 no.6
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• pp.473-479
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• 2016

We report a highly selective and sensitive 200 MHz Surface Acoustic Wave (SAW) sensor that can detect cyanide ion in aqueous solution using surface immobilized thioester molecules in combination with gold nanoparticles (AuNPs). To construct the sensor device, a monolayer of thioester compound was immobilized on the SAW sensor surface. At the sensor surface, hydrolysis of thioester group by nucleophilic addition of cyanide occurred and the resulting free thiol unit bound to AuNP to form thiol-AuNP conjugate. For the signal enhancement, gold staining signal amplification process was introduced subsequently with gold (III) chloride trihydrate and reducing agent, hydroxylamine hydrochloride. The SAW sensor showed a detection ability of $17.7{\mu}M$ for cyanide in aqueous solution and demonstrated a saturation behavior between the frequency shift and the concentration of cyanide ion. On the other hand, our SAW sensor had no activities for other anions such as fluoride ion, acetate ion and sulfate ion, moreover, no significant interference observed by other anions. Finally, all the experiments were carried out in-house developed sensor and fluidics modules to obtain highly reproducible results.

• Journal of Sasang Constitutional Medicine
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• v.11 no.2
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• pp.227-250
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• 1999

The free radical theory of aging was introduced in 1956 by Denham Harman. This aging theory proposed that normal aging results from random deleterious damage to tissues by free radical and supplying antioxidant lead to decrease oxidative damage, inhibit aging process. In this study, we investigated antioxidantive effects of four Korean constitutional prescriptions for 'Soum' constitution - Palmulgunjatang(Y1), Sipyimiguanjungtang(Y2), Osuyubujayijungtang(Y3) and Seungyangyikkibujatang(Y4). Antioxidative activity of this prescriptions was examined by 1,1-diphenyl-2-picrylhyrdazyl radicals, superoxide anion radicals, peroxyl radical, hydroxyl radical scavenging effects and erythrocyte hemolysis inhibitory effects. Y2 and Y3 were shown to have relatively high antioxidative activity on this methods. In additions, result of the cytoprotective effects of Korean constitutional prescriptions agianst 2,2'-azobis(amidinopropane) dihydrochloride (AAPH), a free radical initiator, induced cytotoxcity in human hepatoblastoma cell line was similarly obtained. On the basis of this result, we assayed the antioxidative effects of Y2 and Y3 on experimental oxidative damage, induced in mouse by 100mg/kg AAPH. Male ICR mouse were given oral administration of 500mg/kg Y2 and Y3 for 4 weeks. Thiobarbuturic acid reactive substance (TBARS) and protein degradation level in liver, plasma and brain as index of oxidative damage were decreased and thiol compound, total antioxidant status in plasma were increased by Y2 administration. But, Y3 injected group was decreased only protein degradation level in brain. Also, glutathione, a potent water-soluble endogenous antioxidant, concentration was increased by Y2 and Y3 administration in liver and brain. However, superoxide dismutase and catalase activity as a major antioxidative enzyme in vivo were not shown change by Y2 and Y3 administration. On the basis of these result, Y2 have an antioxidative effects on both water-soluble fraction and lipid-solube fraction in cell and tissues. But, Y3 has a lower antioxidative effects on lipid-soluble fraction than Y2 in cell and tissues. These results suggest that Y2 has a antioxidative effects by protect the tissue against oxygen free radical mediated oxidative damage and Y3 has a limited antioxidaitve effects on water-soluble fraction in vivo. Therefore, we make report that Y2 is more effective prescriptions for anti-aging or therapeutics of diseases.

• Journal of Life Science
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• v.14 no.1
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• pp.148-153
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• 2004

In this study, we investigated the effect of water, extract of Terminalia Chebula (TC) on physiological activity in mice. TC water extract showed hemagglutination against several different types of red blood cells. $LD_{50}$ of TC extract was 390 mg/kg (po). Treatment of TC water extract orally administered 200, 300 mg/kg daily for one week. Hepatic cytosolic enzymes, xanthine oxidase and aldehyde oxidase activities were significantly increased comparison with normal group. Treatment of TC water extract increased hepatic malondialdehyde (MDA) formation, and reduced glutathione content. We also found that the decreased activities of glutathione S-transferase and glutathione reductase but was not affected activities of $\gamma$-glutamylcysteine synthetase after treatment of TC water extract. These results suggested that increase of the hepatic lipid peroxide is caused by glutathione reduction.