• Nuclear Engineering and Technology
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• 제51권7호
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• pp.1715-1720
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• 2019

Jozef Stefan Institute (JSI), TRIGA Mark II reactor employs the homogeneous mixture of uranium and zirconium hydride fuel type. Since its upgrade, a series of fresh fuel steady state experimental benchmarks have been conducted. The benchmark results have provided data for testing computational neutronics codes which are important for reactor design and safety analysis. In this work, we investigated the JSI TRIGA Mark II reactor neutronics characteristics: the effective multiplication factor and two safety parameters, namely the control rod worth and the fuel temperature reactivity coefficient using SuperMC. The modeling and real-time cross section generation methods of SuperMC were evaluated in the investigation. The calculation analysis indicated the following: the effective multiplication factor was influenced by the different cross section data libraries; the control rod worth evaluation was better with Monte Carlo codes; the experimental fuel temperature reactivity coefficient was smaller than calculated results due to change in water temperature. All the results were in good agreement with the experimental values. Hence, SuperMC could be used for the designing and benchmarking of other TRIGA Mark II reactors.

• Toxicological Research
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• 제16권2호
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• pp.95-100
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• 2000

In previous study, both constitutive expression and 3-methylcholanthrene (3MC)-mediated elevation of CYP1A2 mRNA were demonstrated in human hepatoma HepG2 cells by reverse transcription-polymerase chain reaction (RT-PCR), suggesting that HepG2 cells would be appropriate for the study of human CYP1A2 regulation(Chung and Bresnick, 1994). Further studies were conducted to determine the basis of this induction phenomenon that is observed in HepG2 cells. Since CYP1A1 gene, another polycyclic hydrocarbon(PH)-inducible gene, is regulated by PHs through their interactions via receptors with cis-elements, the 5'-flanking region of human CYP 1A2 gene was analyzed to search such responsive elements. The promoter activity of various lengths of CYP1A2 gene sequence (-3203/+58bp) was measured in transiently-transfected HepG2 cells by fusion constructs containing the CAT, hGH or luciferase genes as a reporter. This region of the CYP1A2 gene, although containing a XRE, was only weakly responsive (less than 2 fold induction) to 10 nM of TCDD or 1 $\mu$M 3 MC treatment. This small enhancement of promoter activity is inconsistent with the previous observation, i.e., 12 to 14 fold-enhanced CYP1A2 mRNA from 1 $\mu$M 3 MC treated HepG2 cells, suggesting that additional mechanisms would exist for PH-mediated induction of CYP1A2 in these cells.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1995년도 춘계학술대회
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• pp.128-128
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• 1995

To investigate the mechanism of the regulation of cytochrome P450IA1 gene expression, ethoxyresorufin deethylase(EROD) and benzo(a)pyrene hydroxylase in B6 mouse liver, in isolated perfused rat liver system. and in B6 mouse hepatocyte Hepa-I cells were examined. In C57BL/6N mouse, 3-methylcholan- throne( 3MC ) treatment have resulted in the stimulation of EROD activity based on fluorometry by 2.79 fold comparirng with that of control. Measurement of mRNA of cytochrome P450 was carried out by either nothern blot or dot blot analysis. Findings are similar to that of studies with enzymes. Furhtermore, when RTPCR method was applied to detect mRNA in Hepa I cell and liver tissues the results were more clear. Cytochrome P450IA1 upstream DNA containing CAT construct was transfected into Hepa-1 cells. After transfection of CAT construct, 3MC and flavonoids, such as, chrysin, hesperetin, kaempferol, morin, myricetin and aminoyrine were treated. 48 Hours after treatments, cells were harvested and assayed for CAT mRNA by RTPCR. 3MC treatment to hepa I cells transfected with trout P450IA1-CAT construct increased CAT mRNA by 2.81 fold when it was compared with that of control. This increase CAT mRNA was decreased by concomitantly treated flavonoids and aminopyrine. The level of CAT protein was 29.2-58.0% of 3MC stimulated CAT protein. Results of this study suggested that RTPCR seems to be a very good method to study regulation of gene expression in liver tissue or Hepa cells.

• 한국안광학회지
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• 제18권1호
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• pp.75-84
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• 2013

목적: 연령에 따라 역기하콘택트렌즈(reverse geometry contact lens), MC렌즈(myopia control lens)를 착용 한 후 근시진행억제 효과에 대한 굴절교정값의 변화를 단초점렌즈(single vision lens)와 비교해 알아보고자 한다. 방법: 6세에서 15세 사이의 아동에게 역기하콘택트렌즈 57안, MC렌즈 56안, 단초점렌즈 78안을 각각 착용시킨 후 연령에 따라 Group 1은 10세 이하, Group 2는 11세에서 15세 이하, Group 3은 연구 대상을 모두 포함하여 3그룹으로 나눴다. 이를 바탕으로 12개월 이하, 13~24개월, 25~36개월 까지 굴절교정값의 변화를 통한 근시 진행 억제 효과를 알아보고 통계적 유의성을 검증하고자 하였다. 결과: 착용기간에 따른 굴절교정값의 변화는 Group 3에서 12개월 이하에서는 역기하콘택트렌즈를 착용한 아동에서 변화가 없었고, MC렌즈는 $-0.36{\pm}0.10$ D, 단초점렌즈는 $-0.67{\pm}0.52$ D가 유의하게 변화되었다(P<0.05). 13~24개월에서 역기하콘택트렌즈는 $0.18{\pm}0.49$ D, MC렌즈는 $0.60{\pm}0.42$ D, 단 초점렌즈는 $1.37{\pm}0.72$ D로 유의(P<0.05)하게 변화되었다. 25~36개월에서 역기하콘택트렌즈는 $0.29{\pm}0.61$ D, MC렌즈는 $0.93{\pm}0.57$ D, 단초점렌즈는 $1.72{\pm}0.78$ D로 유의(P<0.05)하게 변화되었다. Group 1에서는 36개월 까지 역기 하콘택트렌즈는 $0.29{\pm}0.73$ D로 MC렌즈는 $1.07{\pm}0.59$ D로 단초점 렌즈는 $1.75{\pm}0.74$ D로 유의(P<0.05)하게 증가하였으며 Group 2에서는 36개월 까지 역기하콘택트렌즈는 $0.28{\pm}0.42$ D로 MC렌즈는 $0.75{\pm}0.49$ D로 단초점 렌즈는 $1.70{\pm}0.84$ D로 유의(P<0.05)하게 증가하여 굴절교정값의 변화는 10세 이하가 11세 이상보다 유의(P<0.05)하게 큰 것으로 나타났다. 결론: 본 연구 결과 12개월 이하의 착용시 역기하콘택트렌즈는 모든 연령에서 굴절교정값의 변화가 없었고, MC렌즈는 모든 연령에서 단초점렌즈보다 더 낮은 시력변화폭을 나타내 근시진행의 억제효과가 있으며, 13~36개월 착용시 역기하콘택트렌즈와 MC렌즈는 모든 연령에서 단초점렌즈보다 낮은 시력변화를 보여 근시진행의 억제효과가 있는 것으로 사료된다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.1411-1414
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• 2008

It is reported that mechanical stimulation takes a role in improving cell growth in skeletal system. And various research groups have showed that developed bioreactor to stimulate cell-seeded and threedimensional scaffold. In this study, we designed a custom-made bioreactor capable of applying controlled compression to cell-seeded agarose gel. This device consisted of a circulation system and compression system. In circular system, culture chamber was sealed for prohibiting contamination and media solution was circulated by pump. In compression system, mechanical stimuli were controlled by LabVIEW software and mechanical transfer system. Cell-encapsulated agarose gels were cultured for up to 7 days. There were significant differences between the number of cells grown in dynamic cell culture and in static cell culture from 3 days to 7 days.

• Journal of Ginseng Research
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• 제44권4호
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• pp.664-671
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• 2020

Background: Ginsenoside compound-Mc1 (Mc1) is a member of the deglycosylated ginsenosides obtained from ginseng extract. Although several ginsenosides have a cardioprotective effect, this has not been demonstrated in ginsenoside Mc1. Methods: We treated H9c2 cells with hydrogen peroxide (H₂O₂) and ginsenoside Mc1 to evaluate the antioxidant effects of Mc1. The levels of antioxidant molecules, catalase, and superoxide dismutase 2 (SOD2) were measured, and cell viability was determined using the Bcl2-associated X protein (Bax):B-cell lymphoma-extra large ratio, a cytotoxicity assay, and flow cytometry. We generated mice with high-fat diet (HFD)-induced obesity using ginsenoside Mc1 and assessed their heart tissues to evaluate the antioxidant effect and the fibrosis-reducing capability of ginsenoside Mc1. Results: Ginsenoside Mc1 significantly increased the level of phosphorylated AMP-activated protein kinase (AMPK) in the H9c2 cells. The expression levels of catalase and SOD2 increased significantly after treatment with ginsenoside Mc1, resulting in a decrease in the production of H₂O₂-mediated reactive oxygen species. Treatment with ginsenoside Mc1 also significantly reduced the H₂O₂-mediated elevation of the Bax:Bcl2 ratio and the number of DNA-damaged cells, which was significantly attenuated by treatment with an AMPK inhibitor. Consistent with the in vitro data, ginsenoside Mc1 upregulated the levels of catalase and SOD2 and decreased the Bax:B-cell lymphoma-extra large ratio and caspase-3 activity in the heart tissues of HFD-induced obese mice, resulting in reduced collagen deposition. Conclusion: Ginsenoside Mc1 decreases oxidative stress and increases cell viability in H9c2 cells and the heart tissue isolated from HFD-fed mice via an AMPK-dependent mechanism, suggesting its potential as a novel therapeutic agent for oxidative stress-related cardiac diseases.

• Toxicological Research
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• 제3권1호
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• pp.1-8
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• 1987

In vitro induction of cytochrome 450 associated monooxygenase activities by phenobarbital (PB) and 3-methylcholanthrene (MC) was investigated in primary cultures of adult rat hepatocytes. PB and MC were added to the culture 24 hr after the initial plating of hepatocytes. A signiftcant increase of the activities of 7-ethoxycoumarin 0-deethylase and aryl hydrocarbon hydroxylase were observed in MC and PB treated culture. MC caused about 500% induction of the initial oxidation rates of both enzymes in 48 hr. However the PB maintained both enzyme activities close to the level of freshly isolated hepatocytes. Biphenyl 4-hydroxylase and aminopyrine N-demethylase activities were also induced by MC and PB. But the level of induction was less than that occuring with 7-ethoxycoumarin 0-deethylase and aryl hydrocarbon hydroxylase. When aflatoxin $B_1$ was added to the hepatocyte cultures which have been treated with MC or PB, it caused a significant increase of the unscheduled DNA synthesis at higher dose of aflatoxin $B_1$ as compared to those of untreated control hepatocyte cultures. The results suggest that microsomal enzyme activities can be selectively controlled preferably in hepatocyte cultures by the in vitro induction method. This principle may be useful for studying the metabolism and other toxicological studies.

• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제11권3호
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• pp.107-114
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• 2022

본 논문에서는 질병관리청 국민건강영양조사(KNHANES: Korea National Health and Nutrition Examination Survey) 데이터베이스에서 특징선택 방법으로 고혈압을 감지 예측하는 방법을 개선했다. 또한 만성 고혈압과 관련된 다양한 위험 요인을 확인하였다. 본 논문은 3가지로 나누어, 첫째 결측값을 제거하고 Z-변환을 하는 데이터 전처리 단계이다. 다음은 데이터 셋에서 특징선택법을 기반으로 하는 요인분석(FA)을 사용하는 특징선택 단계이며, 특징선택을 기반으로 다중공선형 분석(MC)와 특징중요도(FI)을 비교했다. 마지막으로 예측분석단계에서 고혈압 위험을 감지하고 예측하는데 적용했다. 본 연구에서는 각 분류 모델에 대해 ROC 곡선(AUC) 아래의 평균 표준 오차(MSE), F1 점수 및 면적을 비교한다. 테스트 결과 제안한 MC-FA-RF모델은 80.12% 가장 높은 정확도를 보이고, MSE, f-score, AUC 모델의 경우 각각 0.106, 83.49%의, 85.96% 으로 나타났다. 이러한 결과는 고혈압위험 예측에 대한 제안된 MC-FA-RF 방법이 다른 방법에 비해 우수함을 보이고 있다.

• Parasites, Hosts and Diseases
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• 제62권1호
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• pp.1-29
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• 2024

This article analyzed the infection characteristics of metacercariae of Metagonimus spp. (MsMc) in fish from 9 major water systems in Korea. A total of 19,568 fish in 87 species were examined over a period of 10 years (2011-2020). MsMc were detected in fish from all 44 survey areas in 9 water systems. Most of the surveyed sites showed very low and low infection levels (66.7%), while 33.3% of the areas, such as Tamjin-gang and Seomjin-gang, revealed moderate and high infection levels. High endemicity depends on the abundance of susceptible fish species, especially sweet smelt (Plecoglosus altivelis). The susceptibility index (SI) with MsMc in index fish, Zacco spp., was very low and low levels in 62.0%, moderate in 28.0%, and high in 10.0% regions. The SI was highest in the following order: Yeongam-cheon (283.8), Hoeng-cheon (192.3), Togyo-jeosuji (131.2), Deokcheon-gang (119.1), and Joyang-gang (106.3). The recent infection status of MsMc in P. altivelis was analyzed by the survey localities. In addition, except for P. altivelis, 9 fish species were highly infected with MsMc in some survey areas, including Zacco platypus, Z. koreanus, Z. temminckii, Opsariichthys uncirostris, Rhynchocypris oxycephalus, Carassius auratus, Acheilognathus rhombeus, Onchorhynchus masou, and Tribolodon hakonensis. In Korea, 74 fish species (15 families) are collectively listed as second intermediate hosts of Metagonimus spp. This review provides several novel characteristics of MsMc infection and clarifies the fish species of second intermediate host of Metagonimus spp. in this country.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제19권4호
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• pp.395-398
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• 1997

Ipriflavone(IP)은 골흡수 억제효과에 골형성 촉진효과를 지니는 약물로 보고되어 왔다. 이러한 IP의 특성때문에 골의 치유를 촉진시키기 위한 약물로서 구강외과 영역에서 쓰일 수도 있으리라 생각되었다. 이에 저자는 그동안 보고되어온 IP의 골 형성 촉진효과가 실제로 나타나는지를 확인하고 또한 어떤 농도에서 나타나는지를 알아보기위해 IP를 서로다른 농도로 하여 골세포주(MC3T3-El cell line)의 배지에 넣은후, 골 형성의 지표로 쓰일수있는 collagen합성정도를 보고자 하였으며 이 자료를 앞으로서 in vivo 동물실험 연구의 기초자료로 사용코자 하였다. 본 연구에서 IP의 골형성 촉진효과를 collagen 합성정도를 측정을 통해 확인하였고, 특히 IP이 $10^{-7}M$농도일때 현저한 collagen합성의 증가를 관찰 하였으며 앞으로의 동물실험등을 통해 구강외과 영역에서의 사용가능성에 대해 좀더 연구해 보고자 한다.