• Journal of The Korean Society of Clinical Toxicology
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• v.2 no.2
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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.

• The Journal of Internal Korean Medicine
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• v.25 no.3
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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.

• The Journal of Internal Korean Medicine
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• v.25 no.3
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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

• The Journal of Internal Korean Medicine
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• v.24 no.2
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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.

• The Journal of Internal Korean Medicine
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• v.26 no.1
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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.

• The Journal of Internal Korean Medicine
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• v.37 no.6
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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.

• Journal of Korean Society of societal Security
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• v.1 no.4
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• pp.65-71
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• 2008

This paper presents the characteristics of internal erosion of embankment slopes due to the localized heavy rain. In this study, the existing analysis methods of filter performance in embankment materials were reviewed. Based on the theoretical concept of filter conditions to prevent particles from being carried in from the adjacent embankment materials, new analysis method was suggested. According to the new analysis method for filter performance, experimental programs were carried out to investigate the filter performance for controlling and sealing any leak which develops through the embankment materials as a result of internal erosion. Three sets of small scale laboratory tests were carried out with changing the main influence factors such as rainfall intensity, gradient of slope, embankment material condition. It was found that the new analysis method for filter performance to prevent particles from being carried in from the adjacent embankment materials was more capable approach to design the filter materials in embankment slopes. The new criterion or method for satisfactory filter performance, therefore, was recommended.

• Structural Engineering and Mechanics
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• v.32 no.2
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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.

• Journal of the Korean Geotechnical Society
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• v.26 no.4
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• pp.59-68
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• 2010

Piping, a common form of internal embankment erosion, is caused by progressive movement of soil particles through an embankment. The phenomenon commonly occurs with precursory signs of development of fractures in dam structures, but also occurs without any noticeable signs in dams that showed satisfactory dam performance for several years, due to dissolution of soluble material in an embankment. While piping accounts for nearly 50% of the causes for dam failure, few studies have been made for systematic evaluation of the phenomenon. In this study, we attempted to monitor the changes in electrical resistivities of fill-dam material while a saddle dam is dismantled for the construction of emergency spillways of Daechung dam. Two artificial subhorizontal boreholes were drilled into the embankment structure to simulate piping along the two artificial flow channels. Monitoring of changes in electrical resistivity showed an increase in resistivity values during piping. Thus, the investigation of resistivity over time could be an effective method for piping prediction.

• Corrosion Science and Technology
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• v.15 no.4
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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.