• 대한임상독성학회지
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• 제2권2호
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• pp.101-105
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• 2004

Purpose: Paraquat is the most commonly used herbicide in Korea. Exposure to paraquat through the skin has resulted in local irritation or inflammation of varying degree, sometimes severe. The purpose of this study was to review the patients with paraquat poisoning by skin absorption. Methods: We analysed retrospectively the clinical and laboratory findings of 45 patients with paraquat poisoning after dermal exposure, who were admitted to Soonchunhyang University Cheonan Hospital from January 1999 to December 2003. Results: Among 870 cases of paraquat poisoning, 45 cases were exposed to paraquat through the skin. The peak incidence was the fifth decade($40\%$). The clinical symptoms were pain, pruritus, nausea, and vomiting. The major skin lesions were generalized vesicobullae and necrotic erosion in face, scrotum, trunk, upper and lower extremities and etc. All patients were survived after skin contact or inhalation of paraquat. Conclusion: This study illustrates the extreme toxicity of paraquat and demonstrates that lethal quantities of paraquat may be absorbed if repeated exposure to it. Stricter precautions, including the mandatory use of protective clothing, should be recommended whenever this material is used.

• 대한한방내과학회지
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• 제25권3호
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• pp.497-507
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• 2004

This study was carried out to investigate the effects of Ikwitang extract on indomethacin-induced gastric mucosal lesions in mice. Experimental groups were classified into a non-treated group(NM group), a non-administered group(CON group), the Misoprostol-administered group(MI group) and the Ikwitang-extract-administered group(IW group). This study examined the morphological change, distribution of mast cells, mucous surface cells, acid mucose secreted cells, and apoptic cells, BrdU, COX-1, Hsp70, $NF-{\kappa}B\;p50$, PKC, COX-2 and IL-12B of gastric mucosa. Results : The results of this study were as follows: 1. In the Misoprostol-administered group and the Ikwitang-extract-administered group, the hemorrhagic erosion of gastric mucous and infiltrated mast cells decreased. 2. Mucous surface cells and acid mucose secreted cells abserved in the Misoprostol-administered group and the Ikwitang-extract administered group. 3. The distribution of apoptic cells, Hsp70, $NF-{\kappa}B\;p50$, PKC, COX-2, and IL-12B increased in the Control group, but decreased in the Misoprostol-administered group and Ikwitang-extract-administered group. 4. Cells proliferation of gastric mucosa and the COX-l positive cells decreased in the Control group, but increased in the Misoprostol-administered group and the Ikwitang-extract -administered group. The above results suggest the lkwitang extract had beneficial effects on indomethacin induced gastric mucosal lesions.

• 대한한방내과학회지
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• 제25권3호
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• pp.518-528
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• 2004

This study was carried out to investigate the effects of Hyangsapyeongwisan(HP) on gastric mucosal lesions induced by indomethacin in mice. The control group consisted of gastro-inflammation elicited mice. The sample group consisted of mice given HP after onset of gastro-inflammation. In common morphological and histochemical change, various cell abnormalities were observed in the control group, such as mucous surface cell, peanut cell, surface epithelial cell, goblet cell abnormalities, all caused hemorrhagic erosion. The sample group was the same as the control group. In the immunohistochemical change, the distributions of COX-I, BrdU treated with HP were notably higher than those of the control group(p$NF-{\kappa}B$, COX-2, PKC, IL-12B in mice treated with HP were notably lower than those of the control group(p

• 대한한방내과학회지
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• 제24권2호
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• pp.300-314
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• 2003

Objectives : This study was carried out to investigate the effects of Sasammaickmoondong-tang(SME) on duodenal mucosal lesions induced by indomethacin in mouse. Methods : The normal group is that no inflammation elicitated mouse. Control group is that gastro-inflammation elicitated mouse. Sample group is that SME administered mouseice after gastro-inflammation elicitation. Results : In the common morphology and histochemical change, control group was observed various injury-mucous surface cell, micro-villi, paneth cell, surface epithelial cell, goblet cell-by hemorrhagic erosion, while sample group was as same as normal group. In the immunohistochemical change, the distributions of COX-1, Bcl-2, and BrdU treated with SME noticeably increased than control group(p<0.05). The distributions of TUNEL, $NF-{\kappa}B$, COX-2, $IL-2R-{\alpha}$, NK-1.1, ICAM-1, and CD11b/18 treated with SME noticeably decreased than control group(p<0.05). And the distribution of SBA was as same as normal group. Conclusion : According to the above results, it is supposed that Sasammaickmoondong-tang is applicable to duodenal mucosal lesions.

• 대한한방내과학회지
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• 제26권1호
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• pp.244-251
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• 2005

Hiatal hernia occurs when the upper part of the stomach moves up into the chest through a small opening in the diaphragm. It causes various symptoms(heart bum, chest pain, dysphagia, vomiting etc.) when it is associated with a condition called gastroesophageal reflux disease(GERD). In this occasion, complications included bleeding because of the erosion, ulceration and inflammation of the mucosa. For treatment, there are $H_2$ blockers and proton pump inhibitors, but they have many side effects. In Oriental Medicine effectively treated cases are rare. Therefore, it is essential to seek radical agents and effective treatments for these disorders. In this case report, these disorders are approached by focusing on the deficit of 'yin(陰)'especially 'pi-yin(脾陰)'. Desired results were seen with herbal medications which enhance the 'yin(陰)', especially through 'wuyin-jian(五陰煎)' which enhances the 'pi-yin(脾陰)'. This is reported to contribute to development of future treatments.

• 대한한방내과학회지
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• 제37권6호
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• pp.1030-1041
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• 2016

Objectives: This study investigated the administration of Jeungmiyijin-tang (JYT) to rats with reflux esophagitis (RE) induced by pylorus and forestomach ligation operations. Methods: Twenty laboratory rats were divided into three groups with 5~7 rats in each group. The control group consisted of rats with no inflammation (CON). The RE group had rats with gastroesophageal reflux elicited by pylorus and forestomach ligation operations. The JYT group had rats that were orally administered Jeungmiyijin-tang (1.5 ml/day/300 g) once a day for 14 days before reflux esophagitis was induced by the pylorus and forestomach ligation operations. Six hours after the operations, the rats were sacrificed, morphological changes were observed, and histological examinations were done in the stomach and esophagus lesion areas. If apoptosis was observed, the apoptotic cells in the esophagus lesion areas were counted. Results: The morphological and histochemical changes consisted of various injuries from hemorrhagic erosion in the RE group, while there were significantly fewer in the JYT group. The RE group marked increases of gastric mucosa erosion and infiltration of inflammatory cells in the submucosa, as well as cell division in the epithelial layer, the proliferation and degranulation of mast cells, and increases in the IL-$1{\beta}$, TNF-${\alpha}$, and MMP-9 expressions in the esophagus of the rats. The JYT group was inhibited above expression compared with the RE group. Apoptosis was statistically significantly decreased in the JYT group compared with the RE group. Conclusions: According to the above results, it appears that Jeungmiyijin-tang inhibits the expression of pro-inflammatory cytokines (TNF-${\alpha}$, IL-$1{\beta}$, and MMP-9) and apoptosis in the esophagus mucosa, thereby preventing esophageal mucosal damage from esophageal reflux.

• 한국재난관리표준학회지
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• 제1권4호
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• pp.65-71
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• 2008

본 논문은 국지성 호우에 따른 성토사변의 내부 침식의 특성에 대한 것이다. 기존 성토재료의 필터조건 분석방법에 대하여 검토하였다. 근접 성토재료로부터 재료업자의 이동을 억제하기 위한 필터층의 조건을 이론적 배경을 기초로 새로운 분석법을 제안하였다. 이러한 필터거동에 대한 새로운 분석기법에 따라 성토재료 내 침식에 의한 입자간의 거동 특성을 규명하기 위하여 사면의 내부 침식에 영향을 주는 주요원인인자(강우강도, 사면구배, 성토재료 특성 등)를 변화하여 총 3가지 Case의 축소모형실험을 실시하였다. 본 연구로부터 새로운 필터조건 분석법이 실질적인 성토구배 내의 성토재료에 대한 필터 설계시보다 더 적용성이 높은 방법이라는 결론을 얻었다. 이에 따라 새로운 필터조건검토 기준 또는 방법을 제안하였다.

• Structural Engineering and Mechanics
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• 제32권2호
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• pp.283-300
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• 2009

The characteristic response of a structure to blast load may be divided into two distinctive phases, namely the direct blast response during which the shock wave effect and localized damage take place, and the post-blast phase whereby progressive collapse may occur. A reliable post-blast analysis depends on a sound understanding of the direct blast effect. Because of the complex loading environment and the stress wave effects, the analysis on the direct effect often necessitates a high fidelity numerical model with coupled fluid (air) and solid subdomains. In such a modelling framework, an appropriate representation of the blast load and the high nonlinearity of the material response is a key to a reliable outcome. This paper presents a series of calibration study on these two important modelling considerations in a coupled Eulerian-Lagrangian framework using a hydrocode. The calibration of the simulated blast load is carried out for both free air and internal explosions. The simulation of the extreme dynamic response of concrete components is achieved using an advanced concrete damage model in conjunction with an element erosion scheme. Validation simulations are conducted for two representative scenarios; one involves a concrete slab under internal blast, and the other with a RC column under air blast, with a particular focus on the simulation sensitivity to the mesh size and the erosion criterion.

• 한국지반공학회논문집
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• 제26권4호
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• pp.59-68
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• 2010

파이핑은 제체 내부 침식의 한 형태로서 토립자의 진행성 유출에 기인하며 균열이 발생한 댐 뿐만 아니라 용해성 재료로 인하여 수년 동안 만족스런 거동을 보인 댐들에서도 발생한다. 파이핑 현상은 필댐의 붕괴 원인의 약 50%를 차지하고 있으며 필댐 관리의 주요항목이나, 이에 대한 체계적인 평가에는 다소 어려움이 있다. 이에 본 연구에서는 파이핑 현상에 대한 비파괴 탐지를 위한 전기비저항 탐사기법의 적용성을 파악하기 위해 대청댐 비상여수로 건설을 위해 해체되는 부댐에 파이핑 모사시험과 전기비저항 모니터링을 수행하였다. 제체에 수평공을 천공하여 인공적인 유로를 만들고 저수지 물을 유입시켜 실규모 파이핑 현상을 모사하였으며, 파이핑 현상 모사 시험전과 시험 중 측정한 전기비저항값을 비교한 결과 파이핑 발생 시 측정한 전기비저항값이 조금 더 큰 변화를 보임으로써 전기비저항 모니터링 탐사는 실제 담수되어 있는 제체의 파이핑 현상을 효과적으로 탐지할 수 있을 것으로 판단된다.

• Corrosion Science and Technology
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• 제15권4호
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• pp.182-188
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• 2016

Significant piping wall thinning caused by Flow-Accelerated Corrosion (FAC) and Erosion-Corrosion (EC) continues to occur, even after the Mihama Power Station unit 3 secondary pipe rupture in 2004, in which workers were seriously injured or died. Nuclear power plants in many countries have experienced FAC and EC-related cases in steam cycle piping systems. Korea has also experienced piping wall thinning cases including thinning in the downstream straight pipe of a check valve in a feedwater pump line, the downstream elbow of a control valve in a feedwater flow control line, and failure of the straight pipe downstream of an orifice in an auxiliary steam return line. Cause analyses were performed by reviewing thickness data using Ultrasonic Techniques (UT) and, Scanning Electron Microscope (SEM) images for the failed pipe, and numerical simulation results for FAC and EC cases in Korea Nuclear Power Plants. It was concluded that the main cause of wall thinning for the downstream pipe of a check valve is FAC caused by water vortex flow due to the internal flow shape of a check valve, the main cause of wall thinning for the downstream elbow of a control valve is FAC caused by a thickness difference with the upstream pipe, and the main cause of wall thinning for the downstream pipe of an orifice is FAC and EC caused by liquid droplets and vortex flow. In order to investigate more cases, additional analyses were performed with the review of a lot of thickness data for inspected pipes. The results showed that pipe wall thinning was also affected by the operating condition of upstream equipment. Management of FAC and EC based on these cases will focus on the downstream piping of abnormal or unusual operated equipment.