• 한국안전학회지
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• 제19권1호
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• pp.77-80
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• 2004

The purpose of this study was to examine effects of combustion retardation for paper filter impregnated metal salts by measurement of extinguishing concentration, CO concentration, and limiting oxygen index(LOI, ASTM D 2863). And thermal stability analysis using DSC was carried out. In case of extinguishing concentration, $NH_4H_2PO_4$ showed excellent effect of combustion retardation. The result of LOI measurement showed that metal salts possessed good effect of combustion retardation. And thermal analysis using DSC showed that these metal salts possessed thermal stability. In case of CO concentration, CO concentration was increasing because of imperfect combustion process due to combustion retardation effect of metal salts.

• 한국자원식물학회지
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• 제21권6호
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• pp.457-461
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• 2008

Effects of Gal geun (Puerariae Radix) EtOH ext. on lipid lowering and antioxidant were investigated in hyperlipidemic rat. Concentration of FFA and triglyceride in plasma showed a tendency to decrease in Gal geun ext. groups. Concentration of plasma total cholesterol and LDL-cholesterol decreased in Gal geun ext. groups. However the concentration of HDL-cholesterol showed no significantly different in all treatment groups. Concentration of liver total cholesterol and triglyceride showed a tendence to decrease in Gal geun ext. groups. Concentration of plasma and liver TBARS showed a low values in Gal geun ext. groups. The values of GSH-Px and SOD activity showed no significantly different among all the treatment groups. However the values of SOD and CAT activity showed a high value in the Gal geun ext. groups.

• Communications for Statistical Applications and Methods
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• 제30권5호
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• pp.517-530
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• 2023

Recent studies revealed that fine dust in ambient air may cause various health problems such as respiratory diseases and cancer. To prevent the toxic effects of fine dust, it is important to predict the concentration of fine dust in advance and to identify factors that are closely related to fine dust. In this study, we developed a Bayesian network model for predicting PM10 concentration in Seoul, Korea, and visualized the relationship between important factors. The network was trained by using air quality and meteorological data collected in Seoul between 2018 and 2021. The study results showed that current PM10 concentration, season, carbon monoxide (CO) were the top 3 effective factors in 24 hours ahead prediction of PM10 concentration in Seoul, and that there were interactive effects.

• 대한치과교정학회지
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• 제19권1호
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• pp.61-75
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• 1989

Recently, indirect evidences suggest that Na-Ca exchange mechanism is involved in bone resorption. To study this suggestion, effects of several drugs which increase the intracellular sodium concentration by different mechanisms on the PTH-induced bone resorption were analysed employing organ culture. Ulnae and radii were removed from 19-day fetal rats, prelabelled by subcutaneous injection of $200{\mu}\;Ci^{45}CaC1_2$ on the 17th day of gestation, and then explanted on the membrane filters in organ culture dishes. For studying the effects of amiloride, ouabain, monensin, and veratridine on the PTH-induced bone resorption, control group was cultured in BGJb media containing PTH (0.4U/ml) while experimental group was cultured in BGJb media containing PTH and drugs. The effects of drugs on the PTH-induced bone resorption were observed by the ratios of $\%-release$ of $^{45}Ca$ between paired control and experimental groups. The results were as follows: 1. $^{45}Ca$ release was significantly increased by PTH (0.4U/ml) at 48 and 72 hours of culture. 2. Amiloride, at concentration of $500{\mu}M$, significantly inhibited the PTH-induced bone resorption after 48 and 72 hours of culture. 3. Ouabain, at concentration of 0.1 mM, presented significant inhibition of PTH-induced bone resorption after 48 and 72 hours of culture, and at 0.5mM and 1mM, presented significant inhibition of PTH-induced bone resorption after 72 hours of culture. 4. Monensin, at concentration of 500nM, significantly inhibited PTH-induced bone resorption after 72 hours of culture. 5. Veratridine, at concentration of 0.5mM, presented significant inhibition of PTH-induced bone resorption after 48 and 72 hours of culture, and at 1mM, presented significant inhibition of PTH-induced bone resorption after 72 hours of culture. Taken altogether, these results suggest that Na-Ca exchange mechanism play a role in PTH-induced bone resolution.

• 대한약침학회지
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• 제10권3호
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• pp.53-62
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• 2007

Objective The objective of this study was to investigate the antioxidative effects of Puerariae Radix extract. Method Total antioxidant capacity (TAC), Total antioxidant response (TAR), Total phenolic content, Reactive oxygen species (ROS), 1,1-Diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activities, lipid peroxidation were examined. Result Total antioxidant status was examined by total antioxidant capacity(TAC) and total antioxidant response(TAR) against potent free radical reactions. TAC and TAR of Puerariae Radix extract at the concentration of 5 mg/ml were 2.02 and 1.50 mM Trolox equivalents, respectively. Total phenolic content of Puerariae Radix extract at the concentration of 5 mg/ml was 2.29 mM gallic acid equivalent. Concentration of Puerariae Radix extract at which DPPH radical scavenging activity was inhibited by 50% was 5.91 mg/ml as compared to 100% by pyrogallol solution as a reference. The inhibitory effect of the extract on lipid peroxidation was examined using rat liver mitochondria induced by FeSO4/ascorbic acid. Puerariae Radix extract at the concentration of 1 mg/ml slightly but significantly decreased TBARS concentration. The extract further prevented lipid peroxidation in a dose-dependent manner. The effect of Puerariae Radix extract on reactive oxygen species (ROS) generation was examined using cell-free system induced by hydrogen peroxide/FeSO4. Addition of 1 mg/ml of Puerariae Radix extract significantly reduced dichloroflurescein (DCF) fluorescence. The extract caused concentration-dependent attenuation of the increase in DCF fluorescence, indicating that the extract significantly prevented ROS generation in vitro. Thus antioxidant effects of Puerariae Radix extract seem to be due to, at least in part, the prevention from free radicals-induced oxidation, followed by inhibition of lipid peroxidation. Conclusion As a result, Puerariae Radix seems to have antioxitative effect and antioxidant compount.

• 대한한의학회지
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• 제25권4호
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• pp.1-7
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• 2004

Objective : This study was designed to examine the effects of orally administered Prunus persica water extract (PPE), which is used as herbal medicine, for treatment of Yu Xue (stasis of blood) and tacrine on the basal concentration of extracellular acetylcholine in the hippocampus of rats. Methods: To investigate the effects of PPE and tacrine on concentration of extracellular acetylcholine in the hippocampus of rats, the microdialysis technique, under the same experimental conditions, was used. And we used male Wistar rats which were 7 weeks of age and 210-290 g. PPE was extracted with boiling water, and the rats were anesthetized with pentobarbital Na. Their skulls were exposed and a hole was drilled for implantation of a microdialysis probe. In order to increase the recovery of acetylcholine, a probe with a long membrane was used. One day after surgery, the microdialysis probe was perfused with Ringer's solution at a flow rate of 1.5 l/min. The acetylcholine concentration in dialysis samples was measured by high-performance liquid chromatography (HPLC) with electrochemical detection. AChE activity was measured using the radiometric method, as described by Sherman. Results : The comparative effects of PPE and tacrine on hippocampal extracellular acetylcholine concentration was that these cholinesterase inhibitors produced dose-dependent increases in the extracellular acetylcholine concentration. And the effect of PPE and tacrine on rat brain AChE activity was that PPE produced maximal inhibition at 1 h after administration, when AChE activity was 44% of the intact level. AChE activity gradually recovered thereafter, and reached 78% of the intact level at 12 h after administration. Conclusion : In this study, PPE has a potent activity and a long-lasting effect on the central cholinergic system, in terms of the basal concentration of extracellular acetylcholine in the hippocampus and the AChE activity in the brain of rats. And oral administration of PPE increased dose-dependently the basal concentration of extracellular acetylcholine in the hippocampus of rats. PPE may be one of the more useful cholinesterase inhibitors for the treatment of Alzheimer's disease.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
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• pp.892-895
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• 2006

The atmospheric effects on the retrieval of sea ice concentration from passive microwave sensors are examined using simulated data typical for the Arctic summer. The simulation includes atmospheric contributions of cloud liquid water and water vapor and surface wind on surface emissivity on the microwave signatures. A plane parallel radiative transfer model is used to compute brightness temperatures at SSM/I frequencies over surfaces that contain open water, first-year (FY) ice and multi-year (MY) ice and their combinations. Synthetic retrievals in this study use the NASA Team (NT) algorithm for the estimation of sea ice concentrations. This study shows that if the satellite sensor’s field of view is filled with only FY ice the retrieval is not much affected by the atmospheric conditions due to the high contrast between emission signals from FY ice surface and the signals from the atmosphere. Pure MY ice concentration is generally underestimated due to the low MY ice surface emissivity that results in the enhancement of emission signals from the atmospheric parameters. Simulation results in marginal ice areas also show that the atmospheric and surface effects tend to degrade the accuracy at low sea ice concentration. FY ice concentration is overestimated and MY ice concentration is underestimated in the presence of atmospheric water and surface wind at low ice concentration. In particular, our results suggest that strong surface wind is more important than atmospheric water in contributing to the retrieval errors of total ice concentrations over marginal ice zones.

• PNF and Movement
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• 제17권1호
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• pp.57-68
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• 2019

Purpose: This study is an investigation of the effects of long-term smart phone usage and of stretching on muscle stiffness, concentration, and visual acuity. Methods: Forty healthy young adults voluntarily participated in the study and were measured for muscle stiffness, concentration, and visual acuity before smartphone usage and after 30 minutes, 60 minutes, and 90 minutes of smartphone usage. The participants were randomly allocated to the intervention group (n=20) and the control group (n=20). Five minutes after the stretching exercise and eye exercise intervention, the participants were remeasured. Results: After long-term smartphone usage, increases in muscle stiffness and concentration were statistically significant (p<0.05), whereas decreases in visual acuity were statistically significant (p<0.05). After the stretching exercise and eye exercise intervention, muscle stiffness significantly decreased (p<0.05) and visual acuity significantly increased (p<0.05). Concentration, according to the stretching exercise and eye exercise intervention, showed no significant pre- or post-test difference. Conclusion: The results from this study indicate that long-term smartphone usage effectively improved concentration but increased muscle stiffness and decreased visual acuity. Appropriate stretching and eye movement during long-term smartphones usage should mitigate the effects on muscle stiffness and visual acuity. Furthermore, smartphones should be considered an effective tool for concentration training when coupled with the development of appropriate applications.

• 한국식품조리과학회지
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• 제9권1호
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• pp.37-42
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• 1993

이상의 결과에서 다음과 같은 생강 추출물의 항산화 효과를 요약할 수 있었다. 1. 항온 저장시에는 생강 추출물을 첨가한 모든 시료에서 항산화 효과를 나타내었으며 그 효과는 3%를 첨가시 가장 높았고 그 정도는 BHT와는 비슷한 효과를 보였으나 tocopherol에 비해서는 월등히 높은 항산화 효과를 나타내었다. 2. 가열 처리시에도 생강 추출물의 농도에 관계없이 비슷한 정도의 항산화 효과를 나타내었으며 특히 대두유의 경우에는 BHT, tocopherol보다 뚜렷하게 높은 항산화 효과를 보였다. 3. 건강편을 튀김유에 5 및 10%씩 넣고 가열한 후 튀김 횟수에 따른 튀김유의 산패 정도를 측정시 두 시료 모두에서 산패가 억제되었으며 그 중 5%의 건강편이 더 우수한 것으로 나타났다.

• 한국환경보건학회지
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• 제20권3호
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• pp.78-84
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• 1994

The effects of heavy metal, Cd on the degradation of the herbicide butachlor (N-Butoxymethyl-2-chlor-2',6'-diethylacetanilide) in soils were examined the laboratory. The degradation of the herbicide in soil was greatly inhibited by the amendment of the heavy metal, Cd. The inhibited rate of Cd concentration was high in the order of 30 ppm>20 ppm> 10 ppm>0 ppm. And tile degradation rate of butachlor was high in order of 80 $\mu$M>40 $\mu$M>20 $\mu$M. The effects of Cd on the degradation of the butachlor in soil varied with concentration of heavy metal and butachlor.