• The Korean Journal of Mycology
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• v.26 no.4 s.87
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• pp.511-518
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• 1998

Anti-complementary assay for immuno-stimulating polysaccharide screening, human tumor colony-forming assay for discovering anti-tumor drugs, and toxic assay against mouse were performed to examine pharmacological activities of polysaccharides extracted from fruiting bodies of Jang-soo mushroom (Fomitella fraxinea). Hot water $(100^{\circ}C,\;FF-I)$, 1% ammonium oxalate solution $(80^{\circ}C,\;FF-II)$, and 5% sodium hydroxide solution $(80^{\circ}C,\;FF-III)$ were used for extraction of three polysaccharides from fruiting bodies of it. Anti-complementary activity of FF-I was more effective than the others. FF-I was further fractionated into three groups of polysaccharide by DEAE-Sephadex A25 column chromatography (FF-NP, FF-AP1, and FF-AP2). FF-AP1 showed not only the highest anti-complementary activity but also the growth-inhibitory activity against Snu-I (human stomach cancer cell) among 9 kinds of human tumor cell lines. But FF-AP2 exhibited its activity against Hep-2(larynx cancer) and KB(mouth epidermal cancer) cell lines at $500\;{\mu}g/ml$ although its anti-complementary activity was lower than it of FF-AP1. When FF-I was orally administrated to mice with dosage of 5000 mg/kg, no remarkable changes were observed in viewpoint of tissue-pathology.

• The Korean Journal of Mycology
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• v.24 no.4 s.79
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• pp.293-304
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• 1996

A bacterial strain, KSl, possessing strong antifungal activity was isolated from soil samples of ginseng fields and identified as Bacillus subtilis. In greenhouse test, the culture filtrate of B. subtilis KS1 showed strong protective effect against several fungal diseases of agricultural plants such as cucumber gray mold and wheat leaf rust. In addition, the crude butanol fraction of the culture filtrate exhibited antagonistic effect against several fungi including plant or human pathogens, such as Botrytis maydis, Chytridium lagenarium and Candida albicans. The antifungal compound, SW1, produced by B. subtilis KS1 was purified through consecutive chromatographic separations on a pep-RPC column and a ${\mu}$ Bondapak $C_{18}$ reverse phase column. Temperature and pH showed little effect on the stability of the compound in the ranges $-20-121^{\circ}C$ and pH 4.0-10.0, respectively. The composition and structural characteristics of SW1 were analysed by HPLC and by $^1H-,\;^1H-^1H-COSY$, NOESY, COSY-NOESY and HOHAHA NMR spectroscopy, respectively, which revealed that the compound belongs to iturin A, a typical cyclic antifungal compound produced by B. subtilis. In contrast to the previously reported iturin A compounds which have one or no $-CH_3$ side chain in the hydrophobic hydrocarbon chain of ${\beta}-amino$ acids, SW1 was shown to have a ${\beta}-amino$ acid containing 12-carbon skeleton with two $-CH_3$ side chains.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.6
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• pp.782-789
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• 2012

This study was designed to evaluate the anti-metabolic syndrome effects of capsule-filled cheonggukjang (CGJ) added with arrowroot (Pueraria thunbergiana) extracts on body weight, adiposity and lipid metabolism in ob/ob mice. Experimental groups were normal control group (NC: basal diet), positive control group (PC: 2% CGJ), CGJ added with arrowroot extracts group (AR: 2% arrowroot in CGJ), and capsule-filled CGJ added with arrowroot extracts group (ARC: 2% arrowroot CGJ capsule). Each group was fed experimental diet for 10 weeks. Final body weight gain and atherogenic index were significantly lower in the ARC than NC group. Serum levels of total cholesterol, LDL-cholesterol, and triglycerides, blood glucose and atherogenic index were significantly lower in the ARC than NC group. Furthermore, fatty liver and regional lipid accumultion in ob/ob mice were inhibited in the ARC group. The hepatic activities of superoxide dismutase, catalase and glutathione S-transferase were significantly higher in the ARC than NC group. Therefore, the anti-matabolic syndrome effects of the ARC group were higher than the AR group. In conclusion, these results indicated that CGJ added with arrowroot mediates its anti-obesity effects in ob/ob mice by improving lipid metabolism and antioxidant enzyme.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.6
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• pp.774-781
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• 2012

This study investigated dose-response effects of chlorogenic acid (CA) on glucose metabolism and the antioxidant system in streptozotocin (STZ)-induced diabetic mice with a high-fat diet (HFD). Male ICR mice were fed with a HFD (37% calories from fat) for 4 weeks prior to intraperitoneal injection with STZ (100 mg/kg body weight). Diabetic mice were supplemented with two doses of CA (0.02% and 0.05%, wt/wt) for 6 weeks. Both doses of CA significantly improved fasting blood glucose level, glucose tolerance and insulin tolerance without any changes in plasma insulin and C-peptide levels. Plasma leptin concentration was significantly higher in the CA-supplemented groups than in the diabetic control group. Both doses of CA significantly increased hepatic glucokinase activity and decreased glucose-6-phosphatase activity compared to the diabetic control group. The ratio of glucokinase/glucose-6-phosphatase was dose-independently higher in CA-supplemented mice than in diabetic control mice. CA supplementation dose-independently elevated superoxide dismutase and catalase activities, whereas it lowered lipid peroxide levels compared to the diabetic control mice in the liver and erythrocyte. These results suggest that low-dose CA may be used as a hypoglycemic agent in a high-fat diet and STZ-induced diabetic mice.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.1
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• pp.100-108
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• 2015

The purpose of this study is to evaluate the effect of improvement on the impact resistance and strength properties of cement composites by surface modification of aramid fiber. For aramid fiber reinforced cement composites, therefore, dispersion capability and the bonding efficiency between the fibers and the cement composite material need to be improved. It is possible by modifying surface properties to hydrophobic, it is considered that oiling agent ratio of 1.2 % and improvement of performance is in need to be investigated. In this study, short aramid fibers were mixed by different fiber length and oiling agent ratio. And improvement of strength properties and impact resistance performance of hybrid cement composites were evaluated under the influence of steel fiber. As a result, strength properties of aramid fiber reinforced cement composites are different by mixing ratio of fiber, oiling agent ratio and length of fiber. In case of cement composites which have same volume fraction and fiber length, tensile strength and flexural strength were improved with increase of the emulsions throughput of the fiber surface. The results of evaluation on the static strength properties had effects on impact resistance performance by high-velocity impact. And it was observed that the scabbing of rear was suppressed with increase of the oiling agent ratio.

• Journal of the Korean Institute of Intelligent Systems
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• v.3 no.2
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• pp.18-35
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• 1993

The water level control system of the steam generator in a pressurized water reactor and its control problems are analysed. In this work the stable control strategy during the low power operation and transient states is studied. To solve the problem, a fuzzy logic control method is applied as a basic algorithm of the controller. The control algorithm is based on the operator's knowledges and the experiences of manual operation for water level control at the compact nuclear simulator set up in Korea Atomic Energy Research Institute. From a viewpoint of the system realization, the control variables and rules are established considering simpler tuning and the input-output relation. The control strategy includes the dynamic tuning method and employs a substitutional information using the bypass valve opening instead of incorrectly measured signal at the low flow rate as the fuzzy variable of the flow rate during the pressure control mode of the steam generator. It also involves the switching algorithm between the control valves to suppress the perturbation of water level. The simulation results show that both of the fine control action at the small level error and the quick response at the large level error can be obtained and that the performance of the controller is improved.

• Journal of Animal Science and Technology
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• v.48 no.3
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• pp.467-478
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• 2006

Maintenance of an optimal air quality in the enclosed pig building is potentially important in terms of pig performance and farmer health. The objective of this on-site experiment is to evaluate and compare efficiencies of currently utilized biological additives to reduce odor emissions from the enclosed pig building. As a result, generally all the additives except for salt water, artificial spice and essential oil were proved ineffective in reducing odor generation. The beneficial effects of salt water, artificial spice and essential oil on odor reduction were highlighted on ammonia, odor intensity and offensiveness, and sulfuric odorous compounds, respectively. To efficiently utilize odor masking agent such as the artificial spice, ventilation rate should keep slightly lower than the optimal level. Essential oil functioned well as not only masking agent but also antimicrobial agent for reducing odor. To precisely quantify odor concentration, it should be measured by not the odor sensor but the olfactometry technique.

• Journal of Plant Biotechnology
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• v.44 no.3
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• pp.264-270
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• 2017

Brassinosteroid (BR), a plant steroid hormone, plays a critical role in the growth and developmental processes through its canonical signaling and crosstalk with various internal and external signaling pathways. Recent studies have revealed the essential interplay mechanisms between BR and ABA during seed germination and early seedling establishment. However, molecular mechanisms for this important signaling crosstalk are largely unknown. To understand the crosstalk between BR-mediated signaling pathways and ABA functions during early seedling development, we carried out a comparative genome-wide transcriptome analysis with an Agilent Arabidopsis $4{\times}44K$ oligo chip. We selected and compared the expression patterns of ABA response genes in ABA-insensitive bes1-D mutant with wild type seedlings on which ABA was exogenously applied. As a result, we identified 2,353 significant differentially expressed genes (DEGs) in ABA-treated bes1-D and wild type seedlings. GO enrichment analysis revealed that ABA signaling, response, and metabolism were critically down-regulated by BR-activated signaling pathways. In addition, the genome-wide transcriptome analysis data revealed that BR-regulated signaling pathways were tightly connected to diverse signal cues including abiotic/biotic stress, auxin, ROS etc. In this study, we newly identified the molecular mechanisms of BR-mediated repression of ABA signaling outputs. Also, our data suggest that interplay among diverse signaling pathways is critical for the adaptive response of the plant to various environmental factors.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.3
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• pp.387-395
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• 2013

Recently, several circumferential cracks were found in the control rod drive mechanism (CRDM) nozzles of U.S. nuclear power plants. According to the accident analyses, coolant leaks were caused by primary water stress corrosion cracking (PWSCC). The tensile residual stresses caused by welding, corrosion sensitive materials, and boric acid solution cause PWSCC. Therefore, an exact estimation of the residual stress is important for reliable operation. In this study, finite element simulations were conducted to investigate the effects of the tube geometry (thickness and radius) on the residual stresses in a J-groove weld for different CRDM tube locations. Two different tube locations were considered (center-hole and steepest side hill tube), and the tube radius and thickness variables ($r_o/t$=2, 3, 4) included two different reference values ($r_o$=51.6, t=16.9mm).

• Korean Journal of Food Science and Technology
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• v.23 no.2
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• pp.123-128
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• 1991

Addition of two different salt mixtures of sodium phosphates, Ca-EDTA, $NaNO_2$ and sodium citrate were investigated for their effects on relative viscosity, textrue, sensory properties of kimchi and solids contents of kimchi and kimchi liquid during fermentation at $4{\sim}3.5^{\circ}C$. The salt mixtures were added into half fermented kimchi with the concentration range of $0.001{\sim}0.01\;M$. The results showed that higher values in viscosity of kimchi liquids were obtained for those fermented at low temperature and with salts mixtures added. The hardness of Chinese cabbage was gernerally increased until pH 4.0 reached and then decreased thereafter for those fermented without salts mixture. However the salts added kimchi showed no decrease and a slightly harder texture measured at the late stage of fermentation. Soluble solids concentration steadly decreased in kimchi liquids for those salts mixture added while those without salts mixture were initially increased followed by slow decrease. Comparison of sensory properties showed that the degree of changes was reduced when salt mixture was added. Higher scores in fresh-sourness and acidic taste, hardness and chewiness in texture and lower moldy odor were obtained when the data was compared for those kimchi having the pH range of $4.0{\sim}4.2$.