• Development and Reproduction
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• v.13 no.1
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• pp.35-41
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• 2009

In the present study, we investigated the effects of rearing condition during the winter period on artificial maturation and reproduction of cultured female eel, Anguilla japonica. The female eel was adapted by combination of environmental conditions (seawater/low temperature, $10^{\circ}C$; seawater/high temperature, $20^{\circ}C$; freshwater/low temperature, $10^{\circ}C$; freshwater/high temperature, $20^{\circ}C$) during 8 weeks of the winter period. Then, the female eel cultivated by different conditions during the winter were transferred to seawater at $20^{\circ}C$ for induction of artificial maturation by salmon pituitary extraction (SPE) injection. The results shown that gonadosomatic index (GSI) and plasma levels of estradiol-$17{\beta}$ (E2) were significantly higher in female eel were reared in seawater than in freshwater, and were the highest at eel adapted by seawater/low temperature. Also, reproduction coefficient were higher in seawater/low temperature than in the other groups. These results will provide valuable information for elevation of the artificial maturation and reproduction coefficient in the cultured female eel.

• Applied Biological Chemistry
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• v.26 no.2
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• pp.125-131
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• 1983

Formal net charges, bond populations, atomic orbital coefficients, energy components and conformation of dimethyl-2,2-dichlorovinylphosphate have been studied theoretically by using the CNDO/2 molecular orbital calculation method in attempt to describe the reactivity and the stability of the molecule. From the analysis of rate equation, molecular orbital calculations and identification of the hydrolysis products, 2,2-dichloroacetaldehyde and dimethylphosphoric acid, a mechanism of the hydrolysis of dimethyl-2,2-dichlorovinylphosphate(DDVP) has been proposed. The hydrolysis of DDVP proceeds through the mechanism of nucleophilic addition, typical Micheal reaction in basic media. Therefore, it appears probable that the attack by strong nucleophile, hydroxide ion occurs at the increased positive charge $C_2({\alpha})$ atom of a staggered conformation due to the inductive effect (-)I>(+)R of 2,2-dichlorovinyl, electron-attracting group. And then, the hydrolytic scission involves the $C_2({\alpha})-O_3$, ${\pi}-anti-bonding\;orbital({\pi}^*)$ in the subsequent reaction in aqueous solution.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.08a
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• pp.84-91
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• 2002

The stochiometric composition of $AgGaS_2$/GaAs polycrystal source materials for the $AgGaS_2$/GaAs epilayer was prepared from horizontal furnace. From the extrapolation method of X-ray diffraction patterns it was found that the polycrystal $AgGaS_2$/GaAs has tetragonal structure of which lattice constant an and Co were 5.756 $\AA$ and 10.305 $\AA$, respectively. $AgGaS_2$/GaAs epilayer was deposited on throughly etched GaAs(100) substrate from mixed crystal $AgGaS_2$/GaAs by the Hot Wall Epitaxy (HWE) system. The source and substrate temperature were $590^{\circ}C$ and $440^{\circ}C$ respectively. The crystallinity of the grown $AgGaS_2$/GaAs epilayer was investigated by the DCRC (double crystal X-ray diffraction rocking curve). The optical energy gaps were found to be 2.61 eV for $AgGaS_2$/GaAs epilayer at room temperature. The temperature dependence of the photocurrent peak energy is well explained by the Varshni equation, then the constants in the Varshni equation are given by $\alpha=8.695{\times}10^{-4}$ eV/K, and $\beta=332K$. From the photocurrent spectra by illumination of polarized light of the $AgGaS_2$/GaAs epilayer, we have found that crystal field splitting ${\Delta}Cr$ was 0.28 eV at 20 K. From the PL spectra at 20 K, the peaks corresponding to free and bound excitons and a broad emission band due to D-A pairs are identified. The binding energy of the free excitons are determined to be 0.2676 eV and 0.2430 eV and the dissociation energy of the bound excitons to be 0.4695 eV.

• Journal of Korean Society on Water Environment
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• v.23 no.2
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• pp.201-205
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• 2007

This paper reports the amount of $^{222}Rn$ and $^{238}U$ in 18 sites of ground water and 30 sites of surface water. The instrument used to count $^{222}Rn$ activity was the liquid scintillation counter (LSC) which could resolute ${\alpha}$ and ${\beta}$ radiations. And $^{238}U$ was analyzed by the inductively coupled plasma (ICP). Radon and Uranium were not detected in raw and treated water which were sampled in a water treatment plant. However, radon ($^{222}Rn$) was high concentration in ground water from Jeon-la, Gang-won. So was uranium ($^{238}U$) in case of ground water from Gang-won, Choong-chung. Radon ($^{222}Rn$) activities were detected less than 15 pCi/L at 5 sampling points, 15~300 pCi/L at 7 sampling points, 300~4000 pCi/L at 6 sampling points. However, Radon ($^{222}Rn$) activities of all ground water samples were less than 4,000 pCi/L, which was bellow American Alternative Maximum Contamination Level (AMCL). Uranium ($^{238}U$) concentrations were less than $0.1{\mu}g/L$ at 5 sampling points, from $0.1{\mu}g/L$ to $20{\mu}g/L$ at 13 sampling points. Uranium was not detected in about 30% of the whole samples, but the concentration ranged from relatively low to high concentrations depending on the sampling point. The minimum detectable activity (MDA) of radon was 15 pCi/L. and the detection limit of uranium was $0.1{\mu}g/L$.

• Biomolecules & Therapeutics
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• v.6 no.2
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• pp.219-224
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• 1998

The bioequivalence of two clarithromvcin products was evaluated with 16 normal male volunteers (age 23-28 yr, body weight 57.5-75.517g) following single oral dose. Test product was ReYon Clarithromycin tablets (ReYon Pharm. Corp., Korea) and reference product was Klarici $d_{R}$ tablets (Abbott Korea). Both products contain 250 mg of clarithromucin. One tablet of the test or the reference product was administered to the volunteers, respectively, by randomized two period cross-over study (2$\times$2 Latin square method). The determination of clarithromycin was accomplished using a modified agar well diffusion bioassay. As a result of the assay validation, the quantification of clarithromycin in human serum by this technique was possible down to 0.03$\mu$g/ml using 100$\mu$l of serum. The coefficient of variation (C.V.) was less than 10%. Average drug concentrations at each sampling time and pharmacokinetic parameters calculated were not significantly different between two products P>0.05); the area under the curve to last sampling time (24 hr) (AU $Co_{24hr}$ (8.10$\pm$ 1.26 vs 8.22$\pm$ 1.627g . hr/ml), AUC from time zero to infinite (AU $Co_{\infty}$) (8.61 $\pm$ 1.28 vs 8.84$\pm$ 1.71 $\mu$g . hr/ml), maximum plasma concentration ( $C_{msx}$) (0.87$\pm$0.22 vs 0.88$\pm$0.19 $\mu$g/ml) and time to maximum plasma concentration ( $T_{max}$) (2.69 $\pm$0.48 vs 2.56$\pm$ 0.51 hr). The differences of mean AU $Co_{24h}$, $C_{msx}$ and $T_{msx}$ between the two products (1.44, 1.39, and 4.65%, respectively) were less than 20%. The power (1-$\beta$) and treatment difference ($\Delta$) for AU $Co_{24hr}$, and $C_{max}$ were more than 0.8 and less than 0.2, respectivly. Although the power for $T_{max}$ was under 0.8, $T_{max}$. of the two products was not significantly different each other (p>0.05). These results suggest that the bioavailability of ReYon Clarithromycin tablets is not significantly different from that of Klarici $d_{R}$ tablets. Therefore, two products are bioequivalent based on the current results. results.sults.sults.s.s.s.s.s.s.s.

• The Korean Journal of Food And Nutrition
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• v.27 no.1
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• pp.59-65
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• 2014

The fatty acid composition, selected minor components, and the oxidative stability of the mixed edible oil (perilla seed oil and rice bran oil, 3:7 (v/v)) were analyzed. The fatty acid composition of the mixed oil was 32.1% of oleic acid, 30.6% of linoleic acid, 21.4% of linolenic acid, 13.0% of palmitic acid, and 1.7% of stearic acid. The mixed oil contained ${\alpha}$, ${\gamma}$ and ${\delta}$-tocopherols and tocotrienols showing the highest contents of ${\alpha}$-tocopherol. Total amount of tocopherols contained in the mixed oil was 46.63 mg/100 g oil. The composition and content of phytosterols were determined by a GC equipped with a flame ionization detector. Total quantity of phytosterols in the mixed oil was 712.80 mg/100 g oil. The most predominant phytosterol in the mixed oil was ${\beta}$-sitosterol, followed by campesterol and stigmasterol, in a decreasing order. The oxidative stability of the mixed oil was much higher than that of perilla oil, and similar to that of soybean oil, indicating the high oxidative stability of the mixed oil.

• Journal of Nutrition and Health
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• v.28 no.1
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• pp.33-45
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• 1995

Serum levels of antioxidant vitamins and lipids were determined along with anthropometric measurements in 174 healthy male subjects with mean age of 50.3$\pm$6.8 years from Taegu area in Korea. Body mass index (BMI) and waist/hip(W/H) ratio of the subjects were 23.18$\pm$2.46 and 0.88$\pm$0.04, respectively and their systolic and distolic blood pressures were 127.8$\pm$15.5 and 83.9$\pm$10.8mmHg. Twenty one percent of the subject had BMI over 25. Average seum levels of total cholesterol, LDL- and HDL-cholesterol and triglyceride were 187.7$\pm$34.9, 117.6$\pm$33.5, 41.1$\pm$9.0 and 140.7$\pm$83.6mg/dl, respectively. Sixteen percent of the subject had LDL-chole-sterol over 130mg/dl. Serum level of lipid peroxide measured as thiobarbituric acid reactive substances(TBARS) of the subject was 2.01$\pm$0.77 MDA nmoles/ml and those of $\alpha$-tocopherol, retinol. ascorbic acid and sum of $\alpha$- and $\beta$-carotene were 9.59$\pm$3.11$\mu\textrm{g}$/ml, 1.15$\pm$ 0.38$\mu\textrm{g}$/ml, 10.5$\pm$3.8$\mu\textrm{g}$/ml and 64.6$\pm$43.$\mu\textrm{g}$/dl, respectively. About 14% of the sujects had low vitamin E status of less than 7.0$\mu\textrm{g}$/ml,. while 6% had low vitamin C status of less than 4.0$\mu\textrm{g}$/ml, Serum vitamin E showed positive correlations with total cholesterol and LDL-cholesterol and triglyceride, but no correlation with TBARS. Fatty acids of serum total lipid were composed of 42.9% as saturnted. 19.3% as monounsaturated and 36.7% polyunsaturated fatty acids(PUFA). N-6 and n-3 PUFA were 27.7% and 8.3% of total fatty acids. N-6/n-3 PUFA ratios were negatively correlated both with serum total cholesterol and TBARS.

• Journal of Nutrition and Health
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• v.44 no.1
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• pp.16-28
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• 2011

Oxidative stress leads to the induction of cellular oxidative damage, which may cause adverse modifications of DNA, proteins, and lipids. The production of reactive species during oxidative stress contributes to the pathogenesis of many diseases. Antioxidant defenses can neutralize reactive oxygen species and protect against oxidative damage. The aim of this study was to assess the antioxidant status and the degree of DNA damage in Korean young adults using glutathione s-transferase (GST) polymorphisms. The GSTM1 and GSTT1 genotypes were characterized in 245 healthy young adults by smoking status, and their oxidative DNA damage in lymphocytes and antioxidant status were assessed by GST genotype. General characteristics were investigated by simple questionnaire. From the blood of the subjects, GST genotypes; degree of DNA damage in lymphocytes; the erythrocyte activities of superoxide dismutase, catalase, and glutathione peroxidase; plasma concentrations of total peroxyl radical-trapping potential (TRAP), vitamin C, ${\alpha}$- and ${\gamma}$-tocopherol, ${\alpha}$- and ${\beta}$-carotene and cryptoxanthin, as well as plasma lipid profiles, conjugated diene (CD), GOT, and GPT were analyzed. Of the 245 subjects studied, 23.2% were GSTM1 wild genotypes and 33.4% were GSTT1 wild genotype. No difference in erythrocyte activities of superoxide dismutase, catalase, or glutathione peroxidase, and the plasma TRAP level, CD, GOT, and GPT levels were observed between smokers and non-smokers categorized by GSTM1 or GSTT1 genotype. Plasma levels of ${\alpha}$- and ${\gamma}$-tocopherol increased significantly in smokers with the GSTT1 wild genotype (p < 0.05); however, plasma level of ${\alpha}$-carotene decreased significantly in non-smokers with the GSTM1 wild genotype (p < 0.05). DNA damage assessed by the Comet assay was significantly higher in non-smokers with the GSTM1 genotype; whereas DNA damage was significantly lower in non-smokers with the GSTT1 genotype. Total cholesterol and LDL cholesterol levels were significantly higher in non-smokers with the GSTT1 genotype than those with the GSTT1 wild genotype (p < 0.05). In conclusion, the GSTM1 genotype or the GSTT1 wild genotype in non-smokers aggravated their antioxidant status through DNA damage of lymphocytes; however, the GSTT1 wild type in non-smokers had normal plasma total cholesterol and LDL-cholesterol levels. This finding confirms that GST polymorphisms could be an important determinant of antioxidant status and plasma lipid profiles in non-smoking young adults. Further study is necessary to clarify the antioxidant status and/or lipid profiles of smokers with the GST polymorphism and to conduct a study with significantly more subjects.

• Journal of Nutrition and Health
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• v.47 no.3
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• pp.157-166
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• 2014

Purpose: Rice bran is a byproduct of the hulling of rice and contains a variety of bioactive components. Various studies have reported on the antioxidative, anticancer, immune-enhancing, and hypocholesterolemic effects of rice bran. However, few studies about the physiological activity of stabilized rice bran supplement on dietary intake of sugars is limited. The aim of this study was to investigate the effect of stabilized rice bran supplement on blood glucose in C57BL/6 mice fed a high sucrose diet. Methods: Animals were randomly divided into three groups respectively, and were fed a normal diet (ND group), a high sucrose diet (HSD group) or a high sucrose diet containing 20% stabilized rice bran (HSD-SRB group) for 12 weeks. Results: In the oral glucose tolerance test (OGTT), after seven weeks of feeding on the experimental diets, a significantly lower result was observed for HSD-SRB than for HSD at 30 and 60 minutes after oral administration in glucose solution (2 g/kg body weight). The incremental area under the curve (IAUC) of HSD-SRB was significantly lower than that of HSD. After 12 weeks, fasting blood glucose level of HSD-SRB was significantly lower than that of HSD. No significant difference in the serum insulin level was observed between HSD and HSD-SRB. However, HOMA-IR was significantly decreased in HSD-SRB compared to HSD. In addition, HOMA ${\beta}$-cell was significantly increased in HSD-SRB compared to HSD. Triglyceride in liver of HSD-SRB was significantly lower than that of HSD. Conclusion: Feeding diets containing 20% rice bran improved insulin resistance and insulin secretion by decreasing triglyceride in liver. Thus, rice bran has a positive effect on glycemic control. In addition, the results are expected to be utilized as a basis for human study and development of food products with added rice bran.

• Journal of Yeungnam Medical Science
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• v.18 no.1
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• pp.94-100
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• 2001

Background: It is doubtful that aging causes deteriorated glucose metabolism and insulin resistance of skeletal muscle. Some researchers had different results about it. So we have studied the mechanism responsible for the abnormal glucose tolerance associated with aging in rapidly growing and matured rats. Materials and Methods: Animals were used S.D. rats. Growing rats were 7 weeks old (BW: 160-190 gm) and matured rats were 28 weeks old (BW: 420-525 gm). Results: Fasting blood glucose and plasma insulin levels were significantly elevated in matured rat compared with growing rats. And during oral glucose tolerance test the glucose level was also significantly elevated in matured rats. These results confirmed an insulin resistant state of aging. Insulin levels at 30 minutes of oral glucose tolerance test was significantly elevated in growing rat. But at 120 minutes it was maintained at higher level in matured rats than in growing rats. It suggested the possibility of increased insulin secretion by initial stimulation of beta-cells in growing rats, and increased secretion and decreased catabolic rate of insulin in matured rats. Glucose uptake rate of soleus muscle in matured rats was lower than that of growing rats, but the difference was not statistically significant. The dose(insulin)-responsive(glucose uptake) curve of soleus muscle was only slightly deviated to the right side. Conclusion: Glucose metabolism of rat skeletal muscle was worsened by aging. The data of glucose uptake experiments suggested the possibility of insulin resistance of skeletal muscle in matured rats. but the mechanism of insulin resistance of skeletal muscle need further studies.