• International Journal of Oral Biology
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• 제34권1호
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• pp.37-42
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• 2009

The attachment and adhesion of RAW 264.7 and MC3T3-E1 cells to titanium (Ti) discs with various degrees of roughness was investigated. The attachment, adhesion, and proliferation of these cells were evaluated after 4 hr, 24 hr and 7 day incubations. Both RAW 264.7 and MC3T3-E1 cells showed a time-dependant correlation between attachment and adhesion on the surface of the titanium discs. Both types of cells tended to have higher survival rate on these discs as the surface roughness increased. The percentage of adherent inflammatory RAW 264.7 cells was greater than MC3T3-E1 cells at 24 hr, but this was reversed at 7 days in culture. The morphology of osteoblastic MC3T3-E1 cells at 24 hr, determined using a surface emission microscope (SEM), appeared flattened and spread out while inflammatory RAW 264.7 cells were predominantly spherical in shape. The adhesion of both cell types on the titanium discs was dependant on the levels of fibronectin adsorbed on the disc surface, indicating that serum constituents modulate the efficient adhesion of these cells. Our data indicate that the cellular response to the titanium surface is dependent on the types of cells, surface roughness and serum constituents.

• Preventive Nutrition and Food Science
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• 제13권2호
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• pp.61-65
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• 2008

To evaluate the effect of ground cherry extract on the activity of aniline hydroxylase, we gave ground cherry extract in doses of 100, 200 or 400 mg/kg i.p to mice for 1, 2 or 4 days. The aniline hydroxylase activity in the group treated with ground cherry extract increased in a dose dependant manner in all experimental groups compared with the control group, and was significantly higher in the group treated with ground cherry extract at a dose of 200 mg/kg, which also exhibited a time dependant increase over 4 days. Enzyzme kinetic analysis was performed for hepatic aniline hydroxylase activity in the group treated with 200 mg/kg for 4 days. There was no change of the Km values for aniline hydroxylase between the experimental group and the control group, but the Vmax values for aniline hydroxylase was 21% lower in the experimental group compared with the control. The experimental group also showed lower lipid peroxide and reduced glutathione content, and there were no significant difference in serum alanine aminotransferase activity between the experimental group and the control. Aniline was injected into both the experimental group mice treated with ground cherry extract at a dose of 200 mg/kg for 4 days and the control group, and then the level of blood aniline was assayed at 1hr. The level of blood aniline was lower in the experimental than the control group. This study suggests that ground cherry extract induces hepatic aniline hydroxylase activity and might accelerate the scavenging system of reactive oxygen species. It is likely that ground cherry extract influences the metabolism of xenobiotics by activating AH activity substituted for CYP2E1.

• 한국조경학회지
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• 제30권3호
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• pp.73-85
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• 2002

The purpose of this study was to develop prediction models for plant species abundance by stream restoration. Generally the stream plant is affected by stream gemophology. So in this study, the relationship between the vegetation abundance and stream gemophology was developed by multiple regression analysis. The stream characteristics utilized in this study were longitudinal slope, transectional slope, micro-landforms through the longitudinal direction, riparian width and geometric mean diameter and biggest diameter of bed material, and cumulated coarse and fine sand weight portion. The Pyungchang River with mountainous watershed and the Kyungan stream and the Bokha stream in the agricultural region were selected and vegetation species abundance and stream characteristics were documented from the site at 2~3km intervals from the upper stream to the lower. The Models for predicting the vegetation abundance were developed by multiple regression analysis using SPSS statistics package. The linear relationship between the dependant(species abundance) and independant(stream characteristics) variables was tested by a graphical method. Longitudinal and transectional slope had a nonlinear relationship with species abundance. In the next step, the independance between the independant variables was tested and the correlation between independant and dependant variables was tested by the Pearson bivariate correlation test. The selected independant variables were transectional slope, riparian width, and cumulated fine sand weight portion. From the multiple regression analysis, the $R^2$for the Pyungchang river, Kyungan stream, Bokga stream were 0.651, 0.512 and 0.240 respectively. The natural stream configuration in the Pyungchang river had the best result and the lower $R^2$for Kyunan and Bokha stream were due to human impact which disturbed the natural ecosystem. The lowest $R^2$for the Bokha stream was due to the shifting sandy bed. If the stream bed is fugitive, the prediction model may not be valid. Using the multiple regression models, the vegetation abundance could be predicted with stream characteristics such as, transection slope, riaparian width, cumulated fine sand weigth portion, after stream restoration.

• 수산경영론집
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• 제46권1호
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• pp.75-91
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• 2015

With the increasing improvement of living standard, people pay more attention to the quality and security of their food. There is an increase in the consumption of aquatic products and a vast prospect of its trade. Fisheries as a major one of the traditional industries in China have significant price advantages and natural resources. However, marine pollution in China is more and more serious and the expecting of aquatic products has been seriously influenced by green barriers in the recent years. This paper tries to examine the effect of Chinese marine pollution on export of aquatic products in China. This paper utilizes cointegration test to estimate long-run equilibrium between marine pollution and fisheries products export. The results indicate that real exchange rate and income variable have positive effects and fish price has negative effect on China's fisheries export to Korea. However, marine pollution variable has no statistically significant effect on dependant variable. And according to the result of China's fisheries export to Japan, exchange rate has positive effect and both fish price and marine pollution variable have negative effects on export. Lastly, marine pollution and income level have effects on dependant variable in the case of Hong Kong, but exchange rate and price variable have no significant effect on aquatic products export from China to Hong Kong. In a word, marine pollution of China is a serious problem and it has negative effect on Chinese export of aquatic products.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 Asia Navigation Conference
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• pp.134-143
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• 2006

Out of all types of motions the critical motions leading to capsize is roll. The dynamic amplification in case of roll motion may be large for ships as roll natural frequency generally falls within the frequency range of wave energy spectrum typical used for estimation of motion spectrum. Roll motion is highly non-linear in nature. Den are various representations of non-linear damping and restoring available in literature. In this paper an uncoupled non-linear roll equations with three representation of damping and cubic restoring term is solved using a perturbation technique. Damping moment representations are linear plus quadratic velocity damping, angle dependant damping and linear plus cubic velocity dependant damping. Numerical value of linear damping coefficient is almost same for all types but non-linear damping is different. Linear and non-linear damping coefficients are obtained form free roll decay tests. External rolling moment is assumed as deterministic with sinusoidal form. Maximum roll amplitude of non-linear roll equation with various representations of damping is calculated using analytical procedure and compared with experimental results, which are obtained form forced tests in regular waves by varying frequency with three wave heights. Experiments indicate influence of non-linearity at resonance frequency. Both experiment and analytical results indicates increase in maximum roll amplitude with wave slope at resonance. Analytical results are compared with experiment results which indicate maximum roll amplitude analytically obtained with angle dependent and cubic velocity damping are equal and difference from experiments with these damping are less compared to non-linear equation with quadratic velocity damping.

• 동의생리병리학회지
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• 제26권1호
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• pp.59-66
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• 2012

Oxidative stress has been implicated in cutaneous damage in various inflammatory skin diseases, including atopic dermatitis. The present study was undertaken to investigate the antioxidative and anti-inflammatory activities of the extract of Duchesnea chrysantha (DCE). DEC was prepared by extracting with 80% ethanol. Total flavonoids and polyphenols were measured by a colorimetric assay. The free radical scavenging activity of the extract was analyzed by the DPPH (1,1-diphenyl-2-picryl hydrazyl), ABTS (2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) and Griess reagent assay. An oxidative product of nitric oxide (NO), was measured in the culture medium by the Griess reaction. The level of prostaglandin $E_2$ ($PGE_2$) was measured by enzyme-linked immunosorbent assay. The expressions of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) were measured by Western blot analysis. Total flavonoid and polyphenol contents of DCE were included $24.73{\pm}0.45$ and $178.77{\pm}2.65$, respectively. DCE significantly increased electron donating ability (DPPH), nitrite scavenging (NO) and ABTS reducing activity in dose dependant. We investigated the anti-inflammatory effects of DCE on lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. DCE significantly suppressed NO and prdstaglandin $E_2$ ($PGE_2$) in dose dependant. Furthermore, the levels of iNOS and COX-2 protein expressions were markedly suppressed by the treatment with DCE in a dose dependent manner. These results suggest that DEC may has value as natural product with its high quality functional components, antioxidative and anti-inflammatory activities.

• Water Engineering Research
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• 제1권1호
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• pp.25-37
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• 2000

This study presents some results of a preliminary study for the coupled precipitation and river flow prediction system. The model system in based on three numerical models, Mesoscale Atmospheric Simulation model for generating atmospheric variables. Soil-Plant-Snow model for computing interactions within soil-canopy-snow system as well as the energy and water exchange between the atmosphere and underlying surfaces, and TOPMODEL for simulating stream flow, subsurface flow, and water tabled depth in an watershed. The selected study area is the 2,703 $\alpha_4$ $\km_2$ Soyang River basin with outlet at Soyang dam site. In addition to providing the results of rainfall and stream flow predictions, some results of DEM and GIS application are presented. It is obvious that the accurate river flow predictions are highly dependant on the accurate predictation predictions.

• 대한화장품학회지
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• 제15권1호
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• pp.1-36
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• 1989

The protective effects of 24 flavonoids against singlet oxygen - induced photohemolysis of rabbit erythrocytes were investigated and compared with their antioxidant activities. 1. All the flavonoid aglycons investigated besides flavone and 7,8-benzoflavone showed tad dose-dependant Protective effects. Especially galagin showed the most Pronounced effect under the experimental condition. 2. The order of the radical-scavenging activities of flavonoids was as follow (-)-EGCG > flavonols > flavonols > flavones > flavanonols. The radical-scavenging activities of flavonoid glycosides were not different from those of their aglycons. 3. When added after irradiation, flavonoids did not alter the photohemolysis pattern of control. In this study, several antioxidant were found and it was newly found that Photohemolysis experiment is a convenient, reproductive diagnostic method in the screening and researching the compound which has antioxidant activity or protective effect on cell membrane against active oxygen species.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2003년도 사면안정학술발표회
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• pp.3.1-11
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• 2003

Recently the problems related to the failure of the retaining wall structure has become great concern since the damage to the properties and human losses have occurred in the rainy season. However, a detail guideline on safety inspection and appropriate diagnosis on the retaining wall structure have not yet proposed and therefore, the inspection process and results are mainly dependant upon the engineers. The objective of this study is to propose objective and quantitative evaluation method for the condition based on the damage shapes and material types. In this purpose, composing materials of retaining wall are divided Into concrete, gabion, stone and reinforced earth, and then the evaluation items and method are suggested on the basis of the materials and structural characteristics of the retaining wall.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 C
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• pp.1242-1244
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• 1995

The dielectric and polarizable properties of $0.9Pb_{1-x}La_x({Mg}_{1/3}Nb_{2/3})O_3-0.1PbTiO_3$ (x=0,1,2,3,4,5) have been investigated. The temperature-dependant electrostictive characteristics of 0.9PMN-0.1PT relaxor ferroelectric system were improved by enhencing the extent of the diffuse phase transition(DPT). This was achieved using PMN-PTceramics by the partial substitution of La at the Pb site. The curie temperature and the maximum dielectric permittivity decreased by substituting La and the electric field-related hysteresis phenomena decreased with increasing La substitution amount.