• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.6
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• pp.608-616
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• 1992

This study was designed to observe the effects of feeding the mixed oils of the sardine oil containing n-3 EPA, DHA and the safflower oil which is rich in n-6 linoleic acid on the improvement of the lipids and enzyme activities of serum in rats. Experimental oils mixed with 16% butter (control group) and 8% butter + 8% olive oil, 8% butter and various level of sardine and safflower oils were administered to the male rats of the Sprague Dawley for 4 weeks. The activities of aspartate aminotransferase (AST, EC 2.6.1.1), alanine aminotransferase (ALT, EC 2.6.1.2), lactate dehydrogenase (LDH, EC 1.1.1.27) and alkaline phosphatase (ALP, EC 3.1.3.1) in serum were significantly decreased in the all experimental groups than in the control groups, and activities of ALT and LDH were remarkably lower in the group 5 (4% sardine 0il + 4% safflower oil). Concentrations of total cholesterol and HDL-cholesterol in serum were lower in the other groups than in the dontrol groups, and particularly, lowest in the group 5. Concentrations of LDL, LDL-cholesterol, phospholipid and triglyceride in serum were lower in the all experimental groups than in the control group. Concentrations to total cholesterol and cholesteryl ester in serum were lowest in the group 5. The ratio of cholesteryl ester to total cholesterol was remarkably high in the control group, while group 2 (8% olive oil) was the lowest. From this results, the feeding equal quantity mixed oil with n-3 PUFA rich sardine oil and n-6 PUFA rich safflower oil were effective on the improvement of the lipid composition in the serum. It might be due to the effects of appropriate ratios of P/S, 0.85 and n-6/n-3P, 2.85 in the test lipids.

• The Korean Journal of Pesticide Science
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• v.11 no.2
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• pp.95-105
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• 2007

The aim of this study was to determine the residual amounts of PAHs in environmental samples such as crop, soil and water collected from paddy, upland fields and forestlands near industrial zone and/or a thermal power plant in South Korea. All of the samples were analyzed by GC-mass spectrometer. The average contents of total PAHs in soil samples were 140.2 ${\mu}g\;kg^{-1}$ and the range was from 4.3 to $662.9{\mu}g\;kg^{-1}$. The detection of benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene and dibenzo(a,h) anthracene which have strong carcinogenecity was ranged from 14.2 to 167.8 ${\mu}g\;kg^{-1}$. The residual amounts and detection frequency of PAHs in soil samples from the iron and heavy industrial areas near Pohang and Busan were 3-folds more than those of the other areas. Amounts of PAHs in upland soil samples was 1.5 folds higher than those of paddy soil samples, suggesting that it may be related to the content of organic matter in soil. The average contents of total PAHs in crop samples were 9.7 ${\mu}g\;kg^{-1}$ which ranged from 4.5 to 52.2 ${\mu}g\;kg^{-1}$. However, the residual amounts of PAHs in water samples were not detected. These results showed that soils and crops were slightly contaminated with PAHs. Therefore, the investigation should be continued for evaluating a safety or risk assessment through expansion of regions and crops.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.3
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• pp.231-239
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• 2006

In this study, we evaluated the efficiency of using sulfur-$CaCO_3$ complex pellet in the sulfur oxidizing autotrophic denitrification process for synthetic wastewater with high $CaCO_3$ concentration. The sulfur-$CaCO_3$ complex pellet was packed in reactor(R4). Influent ${NO_3}^--N$ loading rate was from 200 to $1,000g/m^3{\cdot}day$. During the operation, average denitrification efficiency of R4 was above 95%. Particularly, the denitrififation rate at $1,000g/m^3{\cdot}day$ loading was 98.96% for R4. High ${NO_3}^--N$ removal efficiency was determined in R4 compared with other reactors. Through $Ca^{2+}$ and alkalinity analyses, we calculated the supplied alkalinity from the packed $CaCO_3$ in the reactor. Sulfur-$CaCO_3$ complex pellet more effectively supplied alkalinity through the dissociation of $CaCO_3$ as compared with other media. Based on these results, sulfur-$CaCO_3$ complex pellet increased the pH buffering capacity while also providing the carbon source to the denitrifying bacteria. Denitrification efficiency of R4 was also higher than other reactors. ESEM pictures of sulfur-$CaCO_3$ complex pellet show higher porosity than that of the granular sulfur. Hence, more denitrifying bacteria attached on the sulfur-$CaCO_3$ complex pellet than on granular sulfur. It can be concluded that the sulfur-$CaCO_3$ complex pellet is a more suitable media for a sulfur oxidizing autotrophic denitrification process as it provides high denitrification efficiency.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.6
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• pp.547-557
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• 1986

The characteristics of the three alkaline proteinases, Enz. A, B and C, from the pyloric caeca of mackerel have been investigated. The optimum condition for the activity of the Enz. A, B and C was pH 9.4, 9.8 and 9.8 at $45^{\circ}C$ for $2\%$ casein solution, and was pH 9.2 10.2 and 9.8 at $45^{\circ}C$ for $5\%$ hemoglobin denatured by urea, respectively. Enz. A, B and C by heat treatment at $50^{\circ}C$ for 5 min were inactivated 90, 33 and $37\%$, respectively, over the original activity. The reaction rate of the three alkaline proteinases was constant to the reaction time to 40 min in the reaction condition of $2{\mu}g/ml$ of enzyme concentration and $2\%$ casein solution. The reaction rate equation and Km value against casein substrate determined by the method of Lineweaver and Burk were: Enz. A, Y=3.6X and $Km=5.0{\times}10^{-3}\%$; Enz. B, Y=6.0X and $Km=1.0{\times}10^{-3}\%$; Enz. C, Y=4.2X and $Km=3.6{\times}10^{-3}\%$. The three alkaline proteinases were inactivated by $Ag^+$ and $Hg^{2+}$, but activated by $Mn^{2+},\;Sn^{2+}\;and\;Pb^{2+}$, Enz. B and C were remarkably inhibited by the soybean trypsin inhibitor. Molecular weight of Enz. A, B and C determined by SDS-polyacrylamide gel electrophoresis and Sephadex G-100 gel filtration was in the range of $27,500{\pm}2,500,\;20,500{\pm}1,500\;and\;15,250{\pm}250$, respectively.

• Restorative Dentistry and Endodontics
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• v.30 no.2
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• pp.128-137
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• 2005

In this study we measured the amount of light energy that was projected through the tooth material and analyzed the degree of polymerization by measuring the surface hardness of composites. For polymerization, Optilux 501 (Demetron, USA) with two types of light guide was used: a 12 mm diameter light guide with 840 nW/$cm^2$ light intensity and a 7 mm diameter turbo light guide with 1100 nW/$cm^2$. Specimens were divided into three groups according to thickness of penetrating tooth (1 mm, 2 mm, 0 mm). Each group was further divided into four subgroups according to type of light guide and curing time (20 seconds, 40 seconds). Vickers' hardness was measured by using a microhardness tester. In 0 mm and 1 mm penetrating tooth group, which were polymerized by a turbo light guide for 40 seconds, showed the highest hardness values. The specimens from 2 mm penetrating tooth group, which were polymerized for 20 seconds, demonstrated the lowest hardness regardless of the types of light guides (p < 0.05). The results of this study suggest that, when projecting tooth material over a specified thickness, the increase of polymerization will be limited even if light intensity or curing time is increased.

• Restorative Dentistry and Endodontics
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• v.33 no.3
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• pp.177-183
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• 2008

It was reported that esthetic composite resin restoration reinforces the strength of remaining tooth structure with preserving the natural tooth structure. However, it is unknown how much the strength would be recovered. The purpose of this study was to compare the fracture resistance of three types of undermined cavity filled with composite resin with that of non-cavitated natural tooth. Forty sound upper molars were allocated randomly into four groups of 10 teeth. After flattening occlusal enamel, undermined cavities were prepared in thirty teeth to make three types of specimens with various thickness of occlusal structure (Group $1{\sim}3$). All the cavity have the 5 mm width mesiodistally and 7 mm depth bucco-lingually. Another natural 10 teeth (Group 4) were used as a control group. Teeth in group 1 have remaining occlusal structure about 1 mm thickness, which was composed of mainly enamel and small amount of dentin. In Group 2, remained thickness was about 1.5 mm, including 0.5 mm thickness dentin. In Group 3, thickness was about 2.0 mm, including 1 mm thickness dentin. Every effort was made to keep the remaining dentin thickness about 0.5 mm from the pulp space in cavitated groups. All the thickness was evaluated with radiographic Length Analyzer program. After acid etching with 37% phosphoric acid, one-bottle adhesive (Single $Bond^{TM}$, 3M/ESPE, USA) was applied following the manufacturer's recommendation and cavities were incrementally filled with hybrid composite resin (Filtek $Z-250^{TM}$, 3M/ESPE, USA). Teeth were stored in distilled water for one day at room temperature, after then, they were finished and polished with Sof-Lex system. All specimens were embedded in acrylic resin and static load was applied to the specimens with a 3 mm diameter stainless steel rod in an Universal testing machine and cross-head speed was 1 mm/min. Maximum load in case of fracture was recorded for each specimen. The data were statistically analyzed using one-way analysis of variance (ANOVA) and a Tukey test at the 95% confidence level. The results were as follows: 1. Fracture resistance of the undermined cavity filled with composite resin was about 75% of the natural tooth. 2. No significant difference in fracture loads of composite resin restoration was found among the three types of cavitated groups. Within the limits of this study, it can be concluded the fracture resistance of the undermined cavity filled with composite resin was lower than that of natural teeth, however remaining tooth structure may be supported and saved by the reinforcement with adhesive restoration, even if that portion consists of mainly enamel and a little dentin structure.

• Korean Journal of Food Science and Technology
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• v.36 no.5
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• pp.804-811
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• 2004

Mean concentration of 2 artificial sweeteners, sodium saccharin and acesulfame K, in food samples and their daily intakes were estimated. Among 755 food samples, 57 contained these artificial sweeteners. Contribution rate to total estimated daily intake (%) of artificial sweeteners in food categories were high in danmooji for sodium saccharin and ice cream for acesulfame K. Total estimated daily intakes $({\Sigma}EDI)$ for different age groups were high in 30-49 year-old group for sodium saccharin and 13-19 year-old group for acesulfame K. Total estimated daily intakes $({\Sigma}EDI)$ of men and women were 5.91 and 4.89 mg/man/day, respectively. Total estimated daily intakes $({\Sigma}EDI)$ based on mean body weight of 55 kg were 4.13 and 1.25 mg/man/day for sodium saccharin and acesulfame K, respectively. These values ranged within 0.2-1.5% of acceptable daily intake (ADI) evaluated by FAO/WHO and 1.2-13.5% of theoretical maximum daily intake (TMDI), and, therefore, judged to be safe.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.8
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• pp.1164-1168
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• 2005

Korean traditional deer decoction (Nogjungtang), composed of oriental herbs and almost deer parts, has been used as an important resource for human health. For basic studying on Nogjungtang, this experiment was conducted to evaluate nutritional effects of Nogjungtang, and estimate its effect on growth, food efficiency, organ development and hematological indices in growing and adult Sprague-Dawley rats. The rats were divided into three groups as follows; control: non-supplementation, Notiungtang I: recommended dose, and Nogjungtang II: thrice recommended dose. Nogjungtang was composed of various general nutrients with up 93$\%$ moisture.Crude protein is the highest value as 22.78$ \%$, Mg is a major mineral as 0.48$\%$ compared to other minerals, and methionine and proline are higher by 1.31 and 1.67$\%$ than other amino acids based on dry matter, re-spectively. In both growing and adult rats, there were no significant difference in body weight gain and feed intake between the control and Nogjungtang groups. Also, organs weights (liver, heart, kidney and stomach) and hematological indices (WBC, RBC, Hb, Hct and Platelet) did not show statistically significant differences among the experimental groups. However, all of experimental rats were normal growth without hypertrophy or negative development of organs by Nogjungtang. Hematological indices maintained in normal value by thrice recommended dose of Nogjungtang. The average body weight of each treatment groups showed similar levels at end of experiment. In case of the feed efficiency ratio (feed intake/body gain), the growing rats showed 6.00, 5.81 and 5.99 and adult rats showed 9.03, 8.98 and 9.10 in control, Nogjungtang I and Nogjungtang II, respectively. In conclusion, although further investigation of Nogjungtang should be performed in the functions registered in many ancient literatures, Nogjungtang is physiologically safe and may have potential as candidate food for human health.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.2
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• pp.315-321
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• 2002

This study was focused on identifying the difference of food preference according to body size of elementary school boys in Daejeon city. In order to measure the food preference, the degree of liking by means of a 5-point Hedonic scale was asked to 198 boys of 5th grade from six schools throughout Daejeon for 144 food items in 17 food groups composed of main dish, side dish and dessert : cooked rice, noodles or breads, as main dish, kimchi, tang.guk.zzigae, gui, zzim, bokeum, fried.pan-fried, jorim, muchim.namul or jangachi, as side dish, fruits, beverage, milk, rice cake or anacks, as dessert and for best preferred taste among five basic. The survey was conducted in rune, 1997 by questionnaires. Overall food preference of the subject was inclined to be higher in most of dessert food : fruits, beverage, milk or snacks, but to be lower in side dishes of Korean conventional food : jangachi, muchim, namul, jorim, kimchi and tang.guk .zzigae. The percentage of boys preferring cocked rice to noodle or bread as main dish was as much almost double in overweight boys as those of underweight or normal weight boys. None of the food group among 17 groups was significantly different in the food preference by body size of the subjects. However, food preference score of overweight group showed a trend to be higher in 11 food groups except less calorie-dense food groups such as fruits, noodles, rice cake, cooked rice, soup and stew and braised food (jorim) than normal or underweight group, and they seemed to prefer especially high-protein and high-fat foods. Being based on 3 points of preference score as the criterion for comparison, underweight group showed higher preference only in fruits group but showed lower preferences in 12 food groups among 17 groups than other groups.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.10
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• pp.1263-1270
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• 2007

This study was carried out to investigate the effect of green tea product (GTP) on the risk factors of atherosclerosis in ovariectomized (OVX) rats. Sprague-Dewley female rats (10 weeks) weighing approximately $279{\pm}2g$ were divided into 4 groups: sham operated control group treated with high cholesterol diet (Sham-C), OVX control group treated with high cholesterol diet (OVX-C), OVX-G 5% group treated with high cholesterol containing 5% GTP and OVX-G 20% group treated with high cholesterol diet containing 20% GTP. Serum TG concentrations was lower in OVX-G 20% group than in the OVX-C group, whereas ratio of HDL-cholesterol to total cholesterol (%) was significantly (p<0.05) increased in the 20% GTP supplementation group than in the Sham-C and OVX-C groups. Tumor necrosis $factor-{\alpha}$ levels were significantly (p<0.05) decreased in the OVX-G 20% group. Hepatic TG levels were significantly (p<0.05) lowered in OVX-G 20% group than in the other groups. Glutathione levels and antioxidant enzyme activities including glutathione-reductase and Mn-superoxide dismutase in liver were significantly (p<0.05) higher in the OVX-G 20% group in the OVX-C group. Fecal total cholesterol concentrations were increased in the GTP supplementation groups than in the OVX-C group. From the above results, it is concluded that GTP may reduce the risk of atherosclerosis via hypolipidemic action. Therefore, it may be used to possibly improve the hyperlipemia in menopausal women.