• Journal of fish pathology
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• v.14 no.2
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• pp.97-102
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• 2001

Olive flounder, Paralichthys olivaceus known as an one of the major aquacultured species in Korea were exposed to cadmium(Cd) with different protocols and analyzed the effects of exposure on the immune response. Antibody levels in sera of the group exposed to Cd(20ppb) by immersion method from 2 weeks before immuniztion with formalinised Edwardsiella tarda(E. tarda) KFE entigen to the end of experiment reached to peak level faster than that of the non-exposed group. After this peaking time the levels decreased much at a faster rate compared to the non-exposed group. This tendency was also appeared in the numbers of specific antibody secreting cells(SASC) analyzed with the enzyme-linked immunospot (ELISPOT)-assay technique in the splenocytes of the experimental groups exposed to Cd with different ways. Interestingly, the group exposed to Cd for 2 weeks before immunization also showed increased numbers of SASC unlikely the antibody production and suggested a more critical influence of cadmium exposure in early stage of immune reaction. Artificial infection with live E. tarda KFE induces 100% mortality in the flounder exposed to cadmium throughout the experimental period from two weeks before the immunization. It may imply that some other factors related to specific immunity are involving in the defence system of flounder exposed to Cd. Taked together. Cd exposure may induce temporaily stimulatory or indhibitory effects on the immune reaction, but suppress the physiological systems for the resistant against the infective agents with other toxic effects.

• Journal of dental hygiene science
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• v.8 no.4
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• pp.255-260
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• 2008

The purposes of this study were to examine the effect of 35% hydrogen peroxide (HP) bleaching agent on the changes in physical and chemical characteristics of tooth. The bleached teeth showed an apparent color changes. The whiteness increased linearly within the tested period as the period of bleaching increased. The microhardness between bleached groups after bleaching showed any statistically significant difference according to the paried t-test. The bleached enamel surface showed any apparent morphological changes compared to the enamel which was stored in distilled water only. The difference of the total mineral contents for the distilled water and hydrogen peroxide did not show statistical significance. These results demonstrated that bleaching using 35% hydrogen peroxide were adversely affects application time of experimental group and may confirm the safety of using these agents for a short time in dentist-monitored bleaching.

• The Korean Journal of Applied Statistics
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• v.33 no.2
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• pp.203-213
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• 2020

The self-controlled case series (SCCS) study measures the relative risk of exposure to exposure period by setting the non-exposure period of the patient as the control period without a separate control group. This method minimizes the bias that occurs when selecting a control group and is often used to measure the risk of adverse events after taking a drug. This study used SCCS to examine the increased risk of side effects when two or more drugs are used in combination. A conditional Poisson model is assumed and analyzed for drug interaction between the narcotic analgesic, tramadol and multi-frequency combination drugs. Bayesian inference is used to solve the overfitting problem of MLE and the normal or Laplace prior distributions are used to measure the sensitivity of the prior distribution.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.8
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• pp.889-895
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• 2012

Carbon fiber reinforced plastic (CFRP) composites have high specific stiffness and high specific strength. Therefore, they are increasingly being use, instead of conventional metallic materials in the aviation and automobile industries, where there is a strong demand for lightweight materials. In aircraft, the fuselage is exposed to severe conditions of high temperatures and high humidity. Therefore, it is necessary to estimate the strength of CFRP composites under real conditions from the viewpoint of aircraft safety. In this study, CFRP specimens were immersed in distilled water at $75^{\circ}C$ for a long time. Then, tensile tests were performed on these specimens, and the fracture characteristics of the fractured surfaces were analyzed using SEM. A fatigue test was performed on specimens immersed for 300 days with R=0.1, and it was confirmed that the fatigue life deteriorated in immersed specimens compared to specimens that were not immersed.

• Korean journal of applied entomology
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• v.61 no.3
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• pp.409-422
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• 2022

Two dominant thrips in hot pepper (Capsicum annuum) cultivating in greenhouses are Frankliniella occidentalis and F. intonsa in Korea. This study investigated their overwintering physiology. These two thrips were freeze-susceptible and suppressed the body freezing temperature by lowering supercooling point (SCP) down to -15~-27℃. However, these SCPs varied among species and developmental stages. SCPs of F. occidentalis were -25.7±0.5℃ for adults, -17.2±0.3℃ for pupae, and -15.0±0.4℃ for larvae. SCPs of F. intonsa were -24.0±1.0℃ for adults, -27.0±0.5℃ for pupae, -17.2±0.8℃ for larvae. Cold injuries of both species occurred at low temperature treatments above SCPs. Thrips mortality increased as the treatment temperature decreased and its exposure period increased. F. occidentalis exhibited higher cold tolerance than F. intonsa. In both species, adults were more cold-tolerant than larvae. Two thrips species exhibited a rapid cold hardening because a pre-exposure to 0℃ for 2 h significantly enhanced the cold tolerance to a lethal cold temperature treatment at -10℃ for 2 h. In addition, a sequential exposure of the thrips to decreasing temperatures made them to be acclimated to low temperatures. To investigate the overwintering sites of the two species, winter monitoring of the thrips was performed at the greenhouses. During winter season (November~February), adults of the two species were not captured in outside of the greenhouses. However, F. occidentalis adults were captured to the traps and observed in weeds within the greenhouses. F. occidentalis adults were also emerged from soil samples obtained from the greenhouses during the winter season. F. intonsa adults did not come out from the soil samples at November and December, but emerged from the soil samples obtained after January. To determine the adult emergence due to diapause development, two thrips species were reared under different photoperiods. Adult development occurred in all photoperiod treatments in F. occidentalis, but did not in F. intonsa especially under short periods. Tomato spotted wilt virus, which is transmitted by these two species, was detected in the weeds infested by the thrips during the winter season. These results suggest that F. occidentalis develops on weeds in the greenhouses while F. intonsa undergoes a diapause in the soil during winter.

• Journal of Life Science
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• v.21 no.8
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• pp.1168-1175
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• 2011

This study was carried out to offer forensic entomological evidence to estimate the post mortem interval (PMI) based on the arthropod succession in pig carrions and carrion decomposition patterns varying with the exposed extent of the carrions. Four carrions, exposed, wrapped, covered or shaded, were placed in an open grassland near the Nakdong-river in Busan in August, 2010. It was found that the first visiting insect was Chrysomyia megacephala among a total of 20 species of 15 families belonging to 7 orders of Insecta, and that four species were useful indicators of the decomposition stage of the carrion: C. megacephala for I~V stages; a species of Sepsidae, Creophilus maxillosus and a species of Carabidae for III~V stages. It was also found that the more the exposed extent of exposure of carrions, the higher the rate of decomposition of carrions, i. e. the time for decomposition of carrions were 7days for the exposed carrion, 10days for the covered one, 13days for the shaded one, and 15days for the wrapped one. This result seems to be related to the differences in the weight loss of carrions caused by strong rains during the research period and by the accessibility of insects to the carrions; both are strongly affected by the exposed extent of the carrions. Accordingly, it was suggested that the exposed extent of the carrions must be taken into consideration to estimate the PMI.

• Korean Journal of Ecology and Environment
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• v.39 no.2 s.116
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• pp.209-218
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• 2006

This study was to evaluate microcystin production by two strains of cyanobacteria (Microcystis aeruginosa and Planktothrix agardhii) in response to three different levels of direct (0,4,8 inds.) or indirect (0,25, 50% of zooplankton culture media filtrate) exposures to zooplankton (Daphnia magna and Moina macrocopa). The cell biomass and intracellular microcystin (MC) were measured everyday. The survival rates of zooplankton were evaluated for daily intervals for the direct exposure. The intracellular MC produced peaked on the day 3 or 4, and then decreased over the both exposure experiment. In the direct experiment, the MC values were significantly different among the control and zooplankton treatments (ZT; repeated measures-ANOVA: P< 0.039). The MC contents of P. agardhii strain (No.204) were significantly higher (Tukey test, P< 0.082) in ZT2 (8 inds.) than in ZT2 (4 inds.). On the peak day, the intracellular MC exposed to both zooplanktons was significantly higher than the control (One-way ANOVA, P< 0.021). Higher zooplankton survivals were observed in the M. aeruginosa strain (No. 111) rather than in high toxic P. agardhii strain. In the indirect experiment, the intracellular MC of the M. aeruginosa strain was significantly different among the control and zooplankton culture media filtrate (ZCMF)treatments (rm-ANOVA: P<0.004), The MC exposed ZCMF2 (50%) were significantly higher than in ZCMFI (25%: Tukey test, P< 0.025) for both strains. This study strongly supports the induced-defensive MC production of potentially toxic cyanobacteria in response to the presence of zooplankton.

• Proceedings of The Korean Society of Health Promotion Conference
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• 2010.05a
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• pp.176-176
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• 2010

알코올연구자, 보건정책연구자, 입법관련전문가, 관련 NGO단체 전문가 등을 중심으로 전문가 집단을 2배수(60명) 선정한 후 확률적으로 30명을 선정하였다. 전문가 핵심 집단연구를 위하여 전문가 패널 국내 전문가 30명에게 목적과 취지를 설명한 후 동의를 구한 후 전자메일을 보내 일정기간 내에 응답하도록 한 후 수거하는 방식을 취하였다. 국내 전문가 조사대상자의 특성은 남성이 19명(61.2%)로 여성 12명(38.8%)보다 많았으며, 40대(64.5%)가 주로 응답을 하였고, 대학교수(67.7%)가 가장 많이 응답하였다. 전문가 집단은 한국인 음주문제에 대한 3문항의 모든 문항에 동의를 하였으며, 동의하지 않은 문항은 없는 것으로 나타났다. '인간관계를 술로 해결하는 관습', '업무상 술자리 많은 사업환경'의 경우 모든 전문가가 매우동의 혹은 동의로 응답하였다. '스트레스 많은 경쟁사회' 83.9%, '저렴한 알코올 가격' 64.5%, '술을 쉽게 접할 수 있는 지역 환경' 80.6%, '생활 대소사에 자주 노출되는 음주환경' 93.6%, '과음 통제할 사회적 통제수단 부족한 점' 90.3%의 경우 모두 매우 동의 혹은 동의로 응답하였다. 이 중 동의율이 가장 높은 문항은 '생활 대소사에 자주 노출되는 음주환경'(93.6%)으로 나타났다. '술을 좋아하는 국민기질' 61.3%, '여가활동을 할 수 없는 사회환경' 77.5%로 다른 문항에 비하여 동의율이 낮았고, 동의 안 한다는 응답도 각각 3.2%, 9.7%가 있는 것으로 나타났다.

• Applied Microscopy
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• v.33 no.3
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• pp.215-222
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• 2003

The ultrastructure of damaged hair shaft from blow-drying at typical temperature $40{\sim}170^{\circ}C$ for daily beautiful face have been investigated by using transmission electron microscope and scanning electron microscope. When we used to hair dryer for a long time in our everyday life, the following morphological alternations were found in hair. First, the partial of scales in outer cuticle were detached simultaneously with separation of intercellular membrane complex of cuticle cells. Then hair broke cuticle off and exposed to cortex. Secondly, the cortical cell in the cortex was fissured into its macrofibril. The melanin granules were scattered between macrofibrils. As a result, I confirmed that blow-drying removed the hair's bonded water and made hard on hair which lost elasticity. After all, hair showed irregular, rough surface and vanished its luster.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05b
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• pp.48-54
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• 1996

가압경수로의 부분충수 운전중 RHR 계통의 기능상실시 사고완화를 위해 가압기 manway와 증기 발생기 출구공동 manway를 동시에 개방한 경우에 대한 실험결과를 CATHAHR2 코드를 이용하여 해석하였다. 해석을 통해 이 경우에 발생하는 물리적 현상을 이해하고 이와 같은 과도기에 대해 코드 예측능력을 평가하므로 써, 실제 원전에서 사고시 적절한 사고대응 방안을 강구하는데 참고가 될 수 있도록 해석적 근거를 제시하고자 한다. 연구결과 CATHARE2 코드는 실험을 통해 관측된 주요 물리적 현상들을 타당하게 예측하였으나, 가압기와 밀림관의 DP를 과대 예측하여 원자로 상부공동의 최대압력을 실험보다 약 7kPa 높게 예측하였다. 노심 노출시간도 노심에서 기포율 분포를 비현실적으로 예측하여 실험보다 약 500초 지연되었다. 실험과 코드의 모의결과를 통하여 노심 노출은 중력주입에 의한 냉각수 보충만으로 충분히 회복될 수 있음을 확인하였다. CATHARE2 코드는 비록 상세한 현상들에 대해 다소 불확실성을 내포하였으나, 전반적인 거동분석에는 타당한 것으로 판단된다. CATHARE 코드는 노심에서 계면 마찰력을 줄임으로써 노심의 차압을 개선할 수 있었고, guide 튜브의 위치를 고온관 중심선과 일치시켜 guide 튜브내 액체의 hold-up 기간을 개선할 수 있었으며, 가압기의 계면 마찰력을 증가시켜서 밀림관에서 "plug and clearing" 현상을 모의할 수 있었다.모의할 수 있었다.