• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.6
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• pp.977-981
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• 2015

The proximate, fatty acid and dimethyl acetal (DMA) compositions of domestic and imported melania snails Semisulcospira sp. being sold commercially were studied. The protein content ranged from 8.09% (China) to 11.3% (North Korea). The lipid content ranged from 0.84 (China) to 2.36% (North Korea). Domestic melania snail had protein (10.5%) and lipid (1.02%) contents intermediate between those of the two imported melania snails. The prominent fatty acids were 16:0 and 18:0 saturated fatty acids, 16:1n-7, 20:1n-11, 18:1n-9, 18:1n-7 and 16:1n-9 monounsaturated fatty acids, and 20:4n-6, 20:5n-3 (eicosapentaenoic acid, EPA), 22:2 non-methylene-interrupted diene (NMID), 18:3n-3, 18:2n-6 and 22:5n-3 (docosapentaenoic acid, DPA) polyunsaturated fatty acids (PUFA). The percentage of n-3 PUFA was higher in domestic (19.6%) and North Korean (imported, 19.5%) snails than in that from China (imported, 16.8%), while the n-6 PUFA level was higher in snails from China (21.2%) and domestic snails (14.7%) than in that from North Korea (9.87%). The total DMA, i.e., 18:0 DMA, 16:0 DMA and 18:1 DMA was 7.30, 7.27, and 4.86% domestic snail and those from China and North Korea, respectively. These results suggest that melania snail is a source of n-3 PUFA, and DMA derived from plasmalogen.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.1
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• pp.25-31
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• 1997

Antioxidative activity of daidzin and puerarin isolated from Puerariae radix against oxidation of low density lipoprotein(LDL) was investigated. The concentration of daidzin at 100$\mu\textrm{g}$/$m\ell$ and puerarin at 60$\mu\textrm{g}$/$m\ell$ inhibited Cu$^{2+}$-mediated oxidation of LDL almost completely. The electrophoretic mobility of oxidized LDL by addition of daidzin(100$\mu\textrm{g}$/$m\ell$) and puerarin(60$\mu\textrm{g}$/$m\ell$) was faster than that of native LDL, but slower than that of oxidized LDL. The oxidized LDL induced by J774 or macrophage was inhibited strongly in the presence of 100$\mu\textrm{g}$/$m\ell$ daidzin and 60$\mu\textrm{g}$/$m\ell$ Puerarin. The formation of conjugated dienes in the oxidized LDL was strongly inhibited by 100$\mu\textrm{g}$/$m\ell$ daidzin and 60$\mu\textrm{g}$/$m\ell$ puerarin.n.

• Journal of Nutrition and Health
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• v.38 no.4
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• pp.289-296
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• 2005

This study was performed to investigate the effect of dietary $\beta$-carotene supplementation on lipid peroxide levels and antioxidant enzyme activities in alcoholic fatty liver rats. Forty five Sprague-Dawley male rats aging 8 weeks were used as experimental animals, which were divided into the control diet (CD) and the ethanol diet (ED) and the ethanol + $0.02\%$ $\beta$-carotene diet (EPD) groups and fed the experimental diet respectively for 5 weeks. After the feeding, rats were sacrificed to get blood and liver to analyze lipid and lipid peroxide levels and antioxidant enzyme activities. The mean body weight and food intake of the ethanol diet group was significantly lower than that of the control diet. The liver index (LI) of the ethanol diet group was significantly higher than those of the control diet and the $\beta$-carotene supplementation group. Serum levels of total lipid, triglyceride of the ethanol diet group were significantly higher than those of the control diet and the $\beta$-carotene supplementation group. Total cholesterol levels were not significantly different among all groups. HDL-cholesterol of the ethanol diet group was significantly lower than those of the control diet and the $\beta$-carotene supplementation group. Liver TBARS of the ethanol diet group was significantly higher than those of the control diet and the $\beta$-carotene supplementation group. Liver lipofuscin and conjugated diene levels were not significantly different among all groups. The superoxide dismutase activity of the ethanol diet group was significantly lower than those of the control diet and the $\beta$-carotene supplementation group. Catalase and glutathione peroxidase activities were not significantly different among all groups. Because v-carotene supplementation significantly decrease the serum total lipid, triglyceride, liver TBARS revels and increase the superoxide dismutase activity in alcoholic ratty liver rats, $\beta$-carotene supplementation seems to give beneficial effect for the alcoholics.

• Journal of Nutrition and Health
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• v.38 no.4
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• pp.297-306
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• 2005

It is known that dehydroepiandrosterone (DHEA) shows a dual effect, prooxidant or antioxidant, depending on the do-sage or physiological status of animals. The purpose of this study was to determine the effects of DHEA administration at low dose on lipid peroxidation, protein carbonylation and fatty acid composition in liver. Sprague Dawley male rats were fed either com oil diet containing $15\%$ com oil or fish oil diet containing $2\%$ corn oil + $13\%$ sardine oil, with or without $0.2\%$ DHEA for 9 weeks. Atherogenic index and hepatic triglyceride and cholesterol levels were significantly reduced by DHEA administration in rats fed with fish oil diet. Hepatic lipid peroxide product (TBARS) and protein carbonyl levels were significantly higher in rats fed with fish oil diet than in rats fed with corn oil diet. However, DHEA administration significantly reduced the hepatic thiobarbituric acid-reactive substance (TBARS) and conjugated diene levels in rats fed with fish oil diet. Contents of C16 : 0, C16 : 1, C20 : 5 and C22 : 6 in hepatic microsome were higher in rats fed with fish oil diet than in rats fed with corn oil diet, and contents of C18 : 2 and C20 : 4 were lower than in rats fed with com oil diet. DHEA administration significantly increased C16 : 0 and C18 : 3 contents and reduced C18 : 2 content in rats fed with com oil diet, while it increased C16 : 0 and C18 : 1 and reduced C20 : 5 and C22 : 6 in rats fed with fish oil diet. On overall, DHEA administration increased saturated fatty acid (SFA) and reduced polyunsaturated fatty acid (PUFA) in hepatic microsome, thereby PUFA/SFA ratio was significantly (p < 0.0001) reduced without the change of n-3/n-6 ratio. Taken together, low dose of DHEA administration lowered PUFA/SFA ratio in hepatic microsomal membranes and also showed antioxidative effect especially in fish oil-induced highly oxidative stress condition through blocking increases of C20 : 5 and C22 : 6 contents.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1998.11a
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• pp.175-175
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• 1998

We reported a new processed ginseng with increased biological activities which is named as “sun ginseng (SG)”. Study on the saponin constituents of SG led to the isolation of seven new ginsenosides named as ginsenoside Rk$_1$, Rk$_2$, Rk$_3$, Rs$_4$, Rs$\_$5/, Rs$\_$6/ and Rs$\_$7/. Ginsenoside Rk$_1$, Rk$_2$ and Rk$_3$ were the Δ$\^$20(21),24(25)/-diene dammarane compounds, while ginsenoside Rs$_4$, Rs$\_$5/, Rs$\_$6/ and Rs$\_$7/ were mono-acetylated compounds. Many other ginsenosides which were reported as minor constituents of red ginseng were also isolated, which include 20(S)-Rg$_3$, 20(R)-Rg$_3$, Rg$\_$5/, Rg$\_$6/, F$_4$, Rh$_4$, 20(S)-Rs$_3$ and 20(R)-Rs$_3$. The major ginsenosides of SG were 20(S)-Rg$_3$, 20(R)-Rg$_3$, Rk$_1$ and Rg$\_$5/.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.5
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• pp.152-162
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• 2005

Coolant rubber hoses for automobile radiators can be degraded and thus failed due to the influence of contacting stresses of air and coolant liquid under the thermal and mechanical loadings. In this study, test analysis was carried out for evaluating the degradation and failure mechanisms of coolant hose materials. Two kinds of EPDM rubber materials applicable to the hoses were adopted: commonly-used ethylene-propylene diene monomer(EPDM) rubbers and EPDM rubbers with high resistance against electro-chemical degradation (ECD). An increase of surface hardness and a large reduction of failure strain were shown due to the formation of oxidation layer for the specimens which had been kept in a high temperature air chamber. Coolant ageing effects took place only by an amount of pure thermal degradation. The specimens degraded by ECD test showed a swelling behavior and a considerable increase in weight on account of the penetration of coolant liquid into the skin and interior of the rubber specimens. The ECD induced material softening as well as drastic reduction in strength and failure strain. However EPDM rubbers designed for high resistance against ECD revealed a large improvement in reduction of failure strain and weight. This study finally established a procedure for reliability analysis and evaluation of the degradation and failure mechanisms of EPDM rubbers used in coolant hoses for automobile radiators.

• Journal of Elementary Mathematics Education in Korea
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• v.17 no.1
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• pp.165-184
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• 2013

In order to utilize Sphinx Puzzle in shape education or deductive reasoning, a lesson employing Dienes' six-stage theory of learning mathematics was structured to be applied to students of 6th grade of elementary school. 4 students of 6th grade of elementary school, the researcher's current workplace, were selected as subjects. The academic achievement level of 4 subjects range across top to medium, who are generally enthusiastic and hardworking in learning activities. During the 3 lessons, the researcher played role as the guide and observer, recorded observation, collected activity sheet written by subjects, presentation materials, essays on the experience, interview data, and analyzed them to the detail. A task of finding every possible triangle out of pieces of Sphinx Puzzle was given, and until 6 steps of formalization was set, students' attitude to find a better way of mathematical deduction, especially that of operational thinking and deductive thinking, was carefully observed and analyzed.

• Food Science and Biotechnology
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• v.16 no.6
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• pp.935-942
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• 2007

The stem bark of Rhus verniciflua (RVSB) has been used in herbal medicine to treat diabetes mellitus and stomach ailments for thousands of years in Korea, despite its content of the plant allergen, urushiol. A new biological approach for the removal of urushiol from RVSB using mushrooms is described. All mushroom species (11 sp.) employed in this study were able to grow on RVSB, although the growth rate (mm/day) was lower than the control (sawdust). The components of urushiol congeners [C15 triene (m/z 314), C15 diene (m/z 316), C15 monoene (m/z 318), and C15 saturated (m/z 320)] were purified by HPLC and identified by GC-MS. A C15:3 (3-pentadecatrienly catechol) was found to be most abundant in RVSB. Urushiol analogues decreased remarkably from 154.15 to 10.73 mg/100 g (approximately 93%) by Fomitella fraxinea, whereas Trametes vercicolor showed only a 1.46% degradation capacity despite its 2 fold higher growth rate. Similarly, laccase activity was found to be high for F. fraxinea and low for T. vercicolor. Moreover, approximately 98% detoxification was accomplished by F. fraxinea cultivated on RVSB supplemented with 20%(w/w) rice bran. These findings suggest that mushrooms can be used in the detoxification of RVSB.

• Korean Journal of Food Science and Technology
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• v.22 no.3
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• pp.255-260
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• 1990

The effects of different concentrations of tocopherols on the oxidation stability of evening primrose oil (EPO) in the dark $(35{\pm}2^{\circ}C)$ were evaluated by some physicochemical characteristics such as peroxide, conjugated diene value and fatty acid composition. The results of the present study were as follows; Alpha-tocopherol at all concentrations (0.02%, 0.05%, 0.10%) showed a prooxidant effect during autoxidation of EPO. This prooxidant activity of alpha-tocopherol increased as its concentration increased rapidly. Delta-tocopherol showed antioxidant activity as its concentration increases at an early stage of storage. But the activity was fairly poor antioxidant activity and was not greater than antioxidant activity of BHT. However, the antioxidant effect of delta-tocopherol and BHT showed no apparent differences as compared with result of none.

• Elastomers and Composites
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• v.35 no.2
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• pp.115-121
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• 2000

In comparison with thermosetting rubber, thermoplastic elastomer (TPE) has various advantages such as simple processing, short cycle time and recycling of scrap. These advantages can lead to development of the high value-added rubber products due to reduction of the waste material, manufacturing cost and the defected product. This article involves a dynamic vulcanization method for EPDM/polypropylene blend, and the manufacturing of a fixed glass weather-strip by glass insert molding method using the blend. In order to investigate mechanical properties of the product, tensile strength, elongation, hardness and specific gravity were measured. Also morphological study was carried out using SEM. Developments of an efficient system of production and automatic process by molding of TPE and glass simultaneously are expected.