• 대한한방내과학회지
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• 제32권2호
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• pp.188-202
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• 2011

Objectives : Oxidative stress seems to play a major role in mechanisms by which ethanol causes liver injury. Previous studies have shown that treatment with Chungganhaeju-tang (Qingganjiejiu-tang, CGHJT) has protective effects on alcoholic liver disease. The aim of this study was to investigate the effects of Chungganhaeju-tang on oxidative stress. Materials and Methods : In vitro, we evaluated the inhibitory activities of CGHJT on DPPH (1,1-diphenyl-2-picryl-hydrazyl), xanthine oxidase, trypsin, and hyaluronidase, and measured cell viability, and proliferation. In the cell culture model, we measured the activities of superoxide dismutase (SOD), and catalase (CAT) after CGHJT treatment in C34 and E47 cell lines, HepG2 cells transfected with/without the cytochrome P450 2E1 (CYP2E1) gene. In vivo, we measured malondialdehyde levels in the liver tissue and alcohol concentration in the blood. Results : CGHJT showed significant free radical scavenging activity against DPPH and xanthine oxidase in the in vitro study, and increased cell viability, proliferation, and activities of superoxide dismutase, catalase in C34 and in E47 cell lines. CGHJT reduced malondialdehyde levels and blood alcohol concentration in vivo, as well. Conclusions : This study suggests that CGHJT has antioxidant effects on oxidative stress by reducing lipid peroxidation and inhibiting the ethanol induced suppression of antioxidant enzyme activities.

• 대한한의학회지
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• 제33권2호
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• pp.11-24
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• 2012

Objectives: This study was designed to evaluate lipid-lowering and antioxidant effects of Artemisia capillaris(A. capillaris) using a model of hyperlipidemic rats induced by poloxamer-407. Methods: Rats were previously treated by A. capillaris water extract, and intraperitoneally injected by poloxamer-407 to induce hyperlipidemia. Parameters of serum lipid and oxidative stress biomarkers were determined. Results: 1. A. capillaris ameliorated the elevation of serum total cholesterol, triglyceride, LDL-cholesterol and MDA level. 2. A. capillaris ameliorated the reduction of serum TAC and SOD activities. 3. A. capillaris ameliorated the reduction of serum GSH and GSH-reductase level. Conclusions: According to these results, A. capillaris can be used to treat hyperlipidemia or as basis for making new drugs for treating hyperlipidemia in the future.

• 대한치과보철학회지
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• 제50권2호
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• pp.99-105
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• 2012

연구 목적: 지금까지 성공적인 임플란트 치료를 위해 많은 연구가 진행되어 왔으며, 임플란트 주변 골 흡수 현상에 대한 연구는 매우 관심이 높은 분야 중 하나이다. 이에 본 연구에서는 삼차원 유한요소응력분석을 이용하여 변연골 흡수가 내측연결 임플란트 매식체의 기계적 안정성에 미치는 영향을 간접적으로 확인하고자 하였다. 연구 재료 및 방법: 악골에 식립된 내측연결 형태의 임플란트 매식체에 티타늄 소재의 임플란트 지대주를 지대주 나사로 연결하고 상부에 금합금관을 장착하는 삼차원 유한요소모형을 설계하였다. 0, 1, 2, 3 mm의 변연골 흡수 상태를 적용하고, 교합면 중심에서부터 3 mm 편측에 300 N의 수직 하중을 가하여 임플란트 매식체에 발생하는 최대 주 응력을 계산하였다. 결과: 유한요소분석결과 변연골 흡수에 따른 임플란트 매식체의 최대 주응력 분포는 유사한 양상을 보였으며, 임플란트 매식체 상단에서 가장 높은 응력 집중이 나타났다. 최대 주응력은 처음 1 mm 변연골 흡수를 가정하였을 때 가장 크게 증가하였고, 이후 변연골 흡수가 증가할수록 응력은 증가하였지만 응력 증가의 폭은 감소하는 경향을 보였다. 결론: 이러한 결과로부터 내측연결 임플란트에서 매식체 두께가 얇은 경부의 노출은 변연골 흡수로 인한 응력 증가에 가장 큰 원인임을 알 수 있었으며, 매식체의 변형, 균열 및 파절 등의 기계적 실패를 감소시키기 위해서는 이에 대한 외과적, 보철적 고려가 필요할 것으로 생각된다.

• Journal of Periodontal and Implant Science
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• 제36권2호
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• pp.473-488
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• 2006

Adequate bone quality and stress distribution to the bone are of decisive importance for implant success. Even though the success rates of dental implants have been high, implant failures do occur. Overloading has been identified as a primary factor behind dental implant failure. The purpose of this study was to theoretically investigate the effect of two types of implants on the stress distribution in poor bone quality. Employing the finite element method, the study modeled a 4.1 mm diameter, 12.0 mm length implant placed in cortical or spongeous bone. A static loading of lOON was applied at the occlusal surface at 0, 30 degrees angle to the vertical axis of the implant. von Mises stresses concentrations in the supporting bone were analyzed with finite element analysis program. The results were as follows; 1. The stresses at the marginal bone were higher under buccal oblique load(30 degrees off of the long axis) than under vertical load. 2. Under buccal oblique load, the stresses were higher at the lingual marginal bone than at the buccal marginal bone, and the differences were almost the same. 3, Under vertical and oblique load, the stress was the highest at the marginal bone and lowest at the bone around apical portions of implant in cortical bone. 4, Under vertical load, Model 1 showed more effective stress distribution than Model 2 irrespective of bone types. On the other hand, Model 2 showed lower stress concentration than Model 1 under buccal oblique load.

• Structural Engineering and Mechanics
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• 제56권3호
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• pp.341-354
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• 2015

The dual-phase lag heat transfer model is employed to study the problem of isotropic generalized thermoelastic medium with internal heat source. The normal mode analysis is used to obtain the exact expressions for displacement components, force stress and temperature distribution. The variations of the considered variables through the horizontal distance are illustrated graphically. The results are discussed and depicted graphically.

• 한국안전학회지
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• 제18권4호
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• pp.28-34
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• 2003

In the present study, three-dimensional finite element analysis was performed to investigate the effects of internal wall thinning defect on the failure pressure of elbow in the piping system and to develop the failure pressure evaluation model. From the results of finite element analysis, the failure pressure was derived by employing local stress criteria, and the effects of thinning location, bend radius, and defect geometry on the failure pressure of internally wall thinned elbow were investigated. Also, based on these investigations and previous model developed to estimate the failure pressure of elbow with an external pitting defect, the failure pressure evaluation model to be applicable to the elbow containing an internal thinning defect was proposed and compared with the results of finite element analysis. The failure pressure calculated by the model agreed well with the results of finite element analysis.

• 대한한방내과학회지
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• 제34권3호
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• pp.256-266
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• 2013

Objectives : The purpose of this study was to investigate the protective effects of Magnolia Officinalis extracts on the animal model of depression induced by immobilization stress. Methods : The subjects were divided into 4 groups : normal, saline solution-administered during immobilization stress, 200 mg/kg of magnolia extracts-administered (magnolia extract 200), and 400 mg/kg of magnolia extracts- administered (magnolia extract 400). During 2 days of immobilization stress treatment, they underwent forced swimming test (FST) and tail suspension test (TST). The number of serotonin (5-HT) immunostained nuclei in the dorsal raphe nucleus regions was measured by immunohistochemistry. Superoxide dismutase (SOD) and glutathione peroxidase (GPX) in blood were measured. Results : In FST, magnolia-administered groups showed significantly decreased immobilization. In TST, the magnolia extract 400 group showed decreased immobilization. The stress group showed significantly decreased number of 5-HT immunostained nuclei in the dorsal raphe nucleus regions, while magnolia extract 400 group showed increased number of 5-HT immunostained nuclei. Stress group showed decrease in serum level of SOD and GPX, while the magnolia extract 200 group showed increase in serum level of SOD and GPX. Conclusions : These results suggest potent effectiveness of magnolia extracts in the treatment of depression.

• 국제초고층학회논문집
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• 제11권4호
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• pp.331-346
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• 2022

Reproducing the horizontally homogeneous atmospheric boundary layer in computational wind engineering is essential for predicting the wind loads on structures. One of the important issues is to use fully developed inflow conditions, which will lead to the consistence problem between inflow condition and internal roughness. Thus, by analyzing the previous results of computational fluid dynamic modeling turbulent horizontally homogeneous atmospheric boundary layer, we modify the past hypotheses, detailly derive a new type of inflow condition for standard k-ε turbulence model. A group of remedial approaches including formulation for wall shear stress and fixing the values of turbulent kinetic energy and turbulent dissipation rate in first wall adjacent layer cells, are also derived to realize the consistence of inflow condition and internal roughness. By combing the approaches with four different sets of inflow conditions, the well-maintained atmospheric boundary layer flow verifies the feasibility and capability of the proposed inflow conditions and remedial approaches.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2006년도 춘계학술대회 논문집
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• pp.136-140
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• 2006

We are developing a vol-oxidizer which transforms the spent $UO_2$ pellets into the $U_3O_8$ power through oxidizing process. The vol-oxidizer consists of furnace, filter, heater and valve etc. When the filter is blocked by the powder, the internal pressure of the furnace is increased owing to the air flow restriction. Then, the furnace vessel is swelled and deformed by it. In this paper, we proposed a procedure of the thermal analysis for furnace vessel design of spent fuel vol-oxidizer. In this work, we determined the thickness of the furnace through analyzing the internal pressure and the thermal stress of the furnace with respect to various pressure and temperature. To analyze the thermal stress, we used ANSYS 8.0 for constructing a FEM model of the furnace, and then analyzed it based on the ASME code. We also surveyed the material property and yield stress of SUS304 with various temperature. Analysis results are compared with the yield stress of the material. We manufactured the furnace and conduct the verification experiments.

• 대한한방내과학회지
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• 제25권4호
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• pp.306-317
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• 2004

Background & Object : Dyspepsia for which no organic causes are disclosed is referred to as functional dyspepsia. Functional dyspepsia is here studied in connection with a biopsychosocial model. From the aspect of individual response to external environment, in connection with stress response, functional dyspepsia is studied by both the psychology department and the internal medicine departments. The disease is taken as approachable from the aspect of internal injury due to seven emotions and stress as differentiated by Oriental medicine. Materials and Methods : Targeted at 223 patients underwent medical checks and endoscopy at Kangnam Korean Hospital, Kyunghee University. They agreed to join this clinical experiment. Stress response inventory, GARS (global assessment of recent stress scale), GSRS (gastrointestinal symptom rating scale), diagnostic scores for Ki-depression, and Spleen Disease Differentiation of Syndromes were all measured and evaluated. The test group was comprised of functional dyspepsia patients. The control group was comprised of nonsymptomatic chronic gastritis patients who were found to suffer from chronical gastritis in endoscopy and thus could be diagnosed with functional dyspepsia if symptoms would arise, but did not complain of subjective symptoms. Results showed these corelations: Functional dyspepsia patients were found to have more serious Ki-depression compared to nonsymptomatic chronic gastritis patients. The more serious Ki-depression the more serious the dyspepsia symptoms. The higher the stress response inventory the more serious the dyspepsia. Deficiency of spleen Eum, and Deficiency and Sinking of spleen Gi were found to coincide with serious Ki-depression.