• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.790-793
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• 2004

The factors influencing concrete deterioration in marine environment can be generally divided into the physical and chemical action. The physical attack due to drying and wetting would increase the internal stress of concrete. The chemical attack resulting from the diffusion of ions$(i,e,\;Cl^-,SO_4^{2-},Mg^+)$ from seawater through the pores in concrete. The objective of this study is to evaluate corrosion characteristics of steel when using the various concrete materials under marine exposure environment. After 3 years of exposure, concrete specimen incorporating $40\%$ blast-furnace slag as replacement for type I cement with low w/c ratio of 0.42 and using the inhibitor shows excellent performance.

• Journal of Yeungnam Medical Science
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• v.37 no.1
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• pp.22-31
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• 2020

There has been a growing concern and subsequent interest surrounding numerous reproductive toxic agents found in various working and non-working environments. Meanwhile, there have been many efforts in medical fields such as toxicology and epidemiology applying experimental studies to elucidate reproductive toxic agents' characterization and health effects. However, there remains insufficient research data and inadequate evidence in humans. Adverse reproductive outcomes vary from transient, moderate health effects to severely detrimental consequences, such as permanent infertility or childhood cancer of one's offspring. Furthermore, upon exposure to toxic agents, the latent period before reproductive health effects are observed is relatively short compared to other occupational diseases (e.g., occupational cancer); instant action is required once exposure to reproductive toxic agents is detected. Therefore, it is very important for workers and healthcare professionals to know about the reproductive toxic agents they are likely to be exposed to. In this review, we discuss the general epidemiology of reproductive health in Korea, and the information regarding these reproductive toxic agents.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.169-172
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• 2006

The IIA structures exposed to marine environment is subject to many different types of potential attack. The physical attack due to drying and wetting would increase the internal stress of concrete. The chemical attack resulting from the diffusion of ions$(Cl^-,SO_4^{2-},Mg^+)$ from seawater through the pores in concrete. Therefore the sea water resistance of concrete must be considered when it is used for structure in the ocean. The objective of this study is to evaluate chloride diffusion and corrosion characteristics of concrete when using the various concrete materials under marine environment. After 5 years of exposure, concrete incorporating 40% blast-furnace slag as replacement for type I cement with low w/c ratio of 0.42 and using the inhibitor shows excellent performance.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.18 no.4
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• pp.615-620
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• 1996

The coronal approach is a versatile surgical technique. This method becomes particulary useful for exposure and internal fixation of midfacial fractures and the harvest of calvarial bone graft to manage the complex facial bone fractures. The rectrospective clinical study on the use of this technique in 10 patients was performed. The result shows that this technique provides the excellent exposure of fractures site, the ability to reduce the fragment accurately and good cosmetic results in incision area. We discussed with literatures review that anatomy, technique, indications, and potential complications of the coronal approach.

• Proceedings of the Optical Society of Korea Conference
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• 2001.02a
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• pp.78-79
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• 2001

노광 후 지연(Post Exposure Delay： PED) 효과는 그림 1과 같이 노광 후 지연 시간에 따른 감광제의 Profile에 thinning, T-top, foot, undercut 를 보여주는 현상으로 화학 증폭형 감광제(Chemically Amplified Resist, CAR) 개발에 있어 PED의 안정성은 중요한 요소이다(1). 따라서 노광후 지연 효과에 대한 모델링은 연구와 개발을 위한 시뮬레이션 tool에 있어 매우 의미 있는 일이다. T-top 이나 undercut 를 형성하는 Surface inhibition layer(SIL) 은 노광 후 지연시 발생되는 environmental base contamination, acid evaporation 이 주요 원인이며 다른 원인으로는 감광제 속에서 acid migration, spin coating 동안에 photoacid generator (PAG)의 고갈, internal basic impurities 이며 그 외에 nonbsic atmospheric contamination, high power laser source의 영향 등이 있다. (중략)

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05b
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• pp.57-60
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• 2005

This study discusses spalling and fire enduring performance of high performance concrete (HPC) RC column subjected to loading under heating for 3 hours. According to the test, both the plain concrete and the concrete attached with fire enduring PC panel exceed allowable temperature after 60 minutes due to the exposure of steel bar and falling off of concrete resulting from severe spalling failure. It leads to buckling of main bar and at the same time, occurrence of collapse of plain HPC column member is observed after 2 hours and 1 hour 40 minutes's exposure to fire, respectively. On the other hand, HPC applying both PP fiber of 0.1$\%$ by mass of concrete and PP fiber+lateral confinement by metal lath maintains their original cross section, which is satisfied with the 3 hours fire endurance criteria, by discharging internal vapour pressure and enhanced lateral confinement force.

• Proceedings of the Korean Society of Toxicology Conference
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• 2002.11b
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• pp.192-192
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• 2002

Hospital waste incinerating workers are exposed to various pyrolysis products including polycyclic aromatic hydrocarbons (PARs). We evaluated their exposure by assessing urinary 1-hydroxypyrene glucuronide (1-OHPG), as internal dose of PAH exposure. The potential effect of genetic polymorphisms of GSTM1/T1 involved in PAH metabolisms was also investigated.(omitted)

• Tuberculosis and Respiratory Diseases
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• v.43 no.4
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• pp.547-557
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• 1996

Background : An excessive accumulation of neutrophils in lung tissue has been known to play an important role in mediating the tissue injury among the adult respiratory distress syndrome, idiopathic pulmonary fibrosis and cystic fibrosis by releasing toxic oxygen radicals and proteolytic enzymes. Therefore, it is important to understand a possible mechanism of neutrophil accumulation in lung tissue. In many species, exposure to hyperoxic stimuli can cause changes of lung tissues very similar to human adult respiratory distress syndrome and neutrophils are also functioning as the main effector cells in hyperoxic lung injury. The purpose of the present study was to examine whether neutrophils function as a key effector cell and to study the nature of possible neutrophil chemotactic factors found in bronchoalveolar lavage fluid from the hyperoxia exposed rats. Methods : We exposed the rats to the more than 95% oxygen for 24, 48, 60 arid 72 hours and bronchoalveolar lavage(BAL) was performed. Neutrophil chemotactic activity was measured from the BAT- fluid of each experimental groups. We also evaluated the molecular weight of neutrophil chemotactic tractors using fast performance liquid chromatography and characterized the substances by dialyzer membrane and heat treatment. Results : 1) The neutrophil proportions in bronchoalveolar lavage fluid began to rise from 48 hours after oxygen exposure, and continued to be significantly increased with exposure times. 2) chemotactic index for neutrophils in lung lavages from rats exposed to hyperoxia was significantly higher in 48 hours group than in control group, and was significantly increased with exposure time. 3) No deaths occured until after 48 hours of exposure. However, mortality rates were increased to 33.3 % in 60 hours group and 81.3 % in 72 fours group. 4) Gel filtration using fast performance liquid chromatography disclosed two peaks of neutrophil chemotactic activity in molecular weight of 104,000 and 12,000 daltons. 5) Chemotactic indices of bronchoalveolar lavage fluid were significantly deceased when bronchoalveolar lavage fluid was treated with heat ($56^{\circ}C$ for 30 min or $100^{\circ}C$ for 10 min) or dialyzed (dialyzer membrane molecular weight cut off : 12,000 daltons). Conclusion : These results suggested that the generation of neutrophil chemotactic factor and subsequent neutrophil influx into the lungs are playing an important roles in hyperoxia-induced acute lung injury. Neutrophil chemotactic factor in the lung lavage fluids consisted of several distinct components having different molecular weight and different physical characteristics.

• The Journal of Internal Korean Medicine
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• v.22 no.1
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• pp.87-93
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• 2001

A human hepatoma cell line, Hep G2 cells, is reliable for the study of alcohol-induced hepatotoxicity. The aim of this study is to determine the relationship between TNF-${\alpha}$, IL-$1{\alpha}$ production and EtOH-induced cytotoxicity on Hep G2 cells. The cells were incubated with EtOH in the presence of Artemisia Capillaris Herba(AC) for 24 hours and in the absence of AC for 48 hours. Cytoviability and cytokines release were analyzed by MTT assay and enzyme linked immunosorbent assay (ELISA), respectively. After 24 hours of EtOH exposure, the cytoviability had markedly decreased, and the release of cytokines had increased. The increased amount of cytokines contributed to EtOH-induced cytotoxicity. Anti-TNF-${\alpha}$ and IL-$1{\alpha}$ antibodies almost abolished it. Interestingly, EtOH-induced cytotoxicity and cytokines production were inhibited by AC. Moreover, when AC was used in combination with antibodies, there was a marked inhibition of EtOH-induced cytotoxicity. These results suggest that EtOH-induced cytotoxicity may regulate, by various factors, and AC may prevent the cytotoxicity through partial inhibition of the $TNF-{\alpha}$ and IL-$1{\alpha}$ secretion.

• Tuberculosis and Respiratory Diseases
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• v.62 no.4
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• pp.323-330
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• 2007

Malignant pleural mesothelioma(MPM) is an uncommon neoplasm which is originated from pleural mesothelial cells. The majority of MPM is associated with prior asbestos exposure. Patients often present with chest pain and dyspnea due to pleural effusion, which might be diagnosed with tuberculous pleurisy especially in Korea. MPM is well known for its poor prognosis with a median survival time of less than 12 months after diagnosis and no established standard treatment modality. We report 3 cases of MPM confirmed by video-assisted thoracoscopic biopsy first misdiagnosed as tuberculous pleurisy.