• BMB Reports
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• v.48 no.2
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• pp.109-114
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• 2015

The COX-2/$PGE_2$ pathway has been implicated in the occurrence and progression of cancer. The underlying mechanisms facilitating the production of COX-2 and its mediator, $PGE_2$, in cancer survival remain unknown. Herein, we investigated $PGE_2$-induced COX-2 expression and signaling in HL-60 cells following menadione treatment. Treatment with $PGE_2$ activated anti-apoptotic proteins such as Bcl-2 and Bcl-xL while reducing pro-apoptotic proteins, thereby enhancing cell survival. $PGE_2$ not only induced COX-2 expression, but also prevented casapse-3, PARP, and lamin B cleavage. Silencing and inhibition of COX-2 with siRNA transfection or treatment with indomethacin led to a pronounced reduction of the extracellular levels of $PGE_2$, and restored the menadione- induced cell death. In addition, pretreatment of cells with the MEK inhibitor PD98059 and the PKA inhibitor H89 abrogated the $PGE_2$-induced expression of COX-2, suggesting involvement of the MAPK and PKA pathways. These results demonstrate that $PGE_2$ signaling acts in an autocrine manner, and specific inhibition of $PGE_2$ will provide a novel approach for the treatment of leukemia.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.6
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• pp.496-501
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• 2007

In order to enhance sintering characteristics on the $ZnO-Pr_6O_{11}$ based multilayer chip varistors (MLVs), a response surface analysis using central composite design method were carried out. As a result, varistor voltage($V_{1mA}$), nonlinear coefficient ($\alpha$), leakage current ($I_L$) and capacitance (C) were considered to be mainly affected by sintered temperature and holding time. MLVs sintered at $1200^{\circ}C$ and above $1200^{\circ}C$ revealed poor electrical characteristics, possibly due to the reaction between electrode materials(Pd) and $ZnO-Pr_6O_{11}$ based ceramics. On the sintering temperature range $1150{\sim}1175^{\circ}C$, nonlinear coefficient ($\alpha$) and leakage current ($I_L$) were shown to be $60{\sim}69$ and below $0.3{\mu}A$, respectively. In particular, MLVs sintered at $1175^{\circ}C$, 1.5 hr and $2^{\circ}C/hr$ (cooling speed) showed stable ESD(Electrical Static Discharge) characteristics under the condition of 10 times at 8 Kv with deviation varistor voltage, and deviation nonlinear coefficient were 0.3% and 0.33% (at positive), 0.55% (at negative), respectively.

• Journal of Power System Engineering
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• v.18 no.6
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• pp.133-139
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• 2014

In this research, the photocatalytic degradation of benzothiophene in $TiO_2$ aqueous suspension has been studied. $TiO_2$ photocatalysts are prepared by a sol-gel method. The dominant anatase-structure on $TiO_2$ particles is observed after calcining the $TiO_2$ gel at $500^{\circ}C$ for 1hr. Photocatalysts with various transition metals (Nd, Pd and Pt) loading are tested to evaluate the effect of transition metal impurities on photodegradation. The photocatalytic degradation in most cases follows first-order kinetics. The maximum photodegradation efficiency is obtained with $TiO_2$ dosage of 0.4g/L. The photodegradation efficiency with Pt-$TiO_2$ is higher than pure $TiO_2$ powder. The optimal content value of Pt is 0.5wt.%. Also we investigate the applicability of $H_2O_2$ to increase the efficiency of the $TiO_2$ photocatalytic degradation of benzothiophene. The optimal concentration of $H_2O_2$ is 0.05. The effect of pH is investigated; we obtain the maximum photodegradation efficiency at pH 9. Hydroxy-benzothiophenes and dihydroxy-benzothiophenes are identified as reaction intermediates. It is proposed that benzothiophene is oxidized by OH radical to sequentially form hydroxyl-benzothiophenes, dihydroxybenzothiophenes, and benzothiophenedione.

• Journal of Sericultural and Entomological Science
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• v.43 no.1
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• pp.33-36
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• 2001

This study was carried out to improve the liquid culture methods of Paecilomyces japonica. The results show that the size of granular mycelium is smaller when the shaking speed is increased. Especially, the granular mycelium is the smallest at the shaking speed of 150rpm under the photoperiod of 12L-12D. Dry weight of mycelium was averagely 1.216 g in the Sikworm larva (SL) medium, and the weight was 2 times heavier than in the Potato dextrose (PD) medium. By adding 6 g of 6 mmbeads in the SL medium, the dry weight is increased to 1.332 g. The optimal addition of silkworm larval powder to the culture medium for gest harvest was 1.360$\pm$0.67 g in dry weight.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.12
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• pp.1086-1092
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• 2000

To realize a visual servo control of slender manipulators, two problems to be solved are analysed. The stability problem on so-called noncolocation control and the infinite order problem of the real Jacobian matrix caused by the elastic deformation are discussed. By considering the dynamic relations between rigid and elastic modes, a Jacobian operator is derived and the physical meaning is also explained. Then, for practical control, a simple control scheme using an approximate Jacobian is proposed and its stable conditions are proven by means of the $L_$2$ stability theory. The scheme is structurally similar to the conventional PD control laws, but external sensors(e. g. visual sensor) are used for positioning and internal sensors for damping. A good performance is obtained via control experiments of a slender two link manipulator.

• YAKHAK HOEJI
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• v.54 no.2
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• pp.134-141
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• 2010

It is well known that the numbers and functions of immune-associated cells are increased by saponins and polysaccharides in ginseng. In this study, the mixture of polysaccharide and saponin (MPS) from Panax ginseng is applied to LPS- activated RAW 264.7 cells. The production of NO and the gene expression of IL-6 and TNF-$\alpha$ are decreased in LPSactivated RAW 264.7 cells and the expression of arginase II and PD-1L genes is decreased in LPS-untreated macrophages. Therefore, the mixture of saponin and polysaccharide from Panax ginseng could be used in order to regulate immune responses.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.11a
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• pp.347-348
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• 2022

자율운항선박 도입에 관한 논의가 국제해사기구에서 본격적으로 시작됨에 따라 자율운항선박 관련 기술개발이 세계적으로 활발하게 진행되고 있다. 그러나, 통신, 보안, 고장진단, 유지보수 등의 기술개발이 아직 미흡하여, 자율운항선박의 상용화까지는 많은 시간이 소요될 것으로 예상된다. 이러한 기술들은 문제가 발생할 경우 선박에 막대한 피해를 발생시킬 수 있으며, 특히, 연안을 항해하는 선박보다는 대양을 항해하는 선박에 더 치명적이기 때문이다. 본 연구에서는 대양항해 시 자율운항선박에 발생할 수 있는 문제들을 극복하기 위한 방안으로 여러 척의 선박을 하나의 그룹으로 묶어 항해하는 그룹항법시스템을 제안한다. 하나의 그룹은 한 척의 유인선박인 리더선박과 여러 척의 무인선박인 추종선박으로 구성되어 있으며, 항해하는 동안 일직선 형태를 유지한다. 리더선박은 출발지에서 목적지까지 미리 설정된 변침점을 따라 항해하며, 추종선박은 리더선박의 경로를 추종하여 항해한다. 선박의 침로를 제어하기 위한 타각 제어기는 선박에서 주로 사용되는 PD 제어기를 구현하여 사용하였다. 그룹항법시스템을 검증하기 위해 선박해양플랜트연구소에서 공개한 KVLCC2의 축소 모형인 L-7 모델을 사용하여 시뮬레이션을 진행하였다.

• Biomedical Science Letters
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• v.28 no.1
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• pp.25-33
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• 2022

The imbalance of oxidative stress due to the excessive production of reactive oxygen species (ROS) leads to the pathogenesis of liver disease. To prevent this, the role of antioxidant mechanisms is important. Antioxidant studies have been reported on the Filipendula glaberrima Nakai. However, studies applied to HepG2 cells, which are human liver cells, have not yet been conducted. In this study, 70% ethanol extract of Filipendula glaberrima Nakai (FGE) was prepared and antioxidant activity was investigated. It was confirmed whether FGE pretreatment could reduce hydrogen peroxide-induced oxidative stress in HepG2 cells. The increase in gene expression of antioxidant biomarkers and the scavenging ability of ROS were measured, and Hoechst 33342 staining was used to know the inhibitory effect of the apoptosis. As a result, FGE significantly increased SOD (2.6-fold), CAT (4.4-fold), MT-1A (3.1-fold), GPx (4-fold), and G6PD (2.4)-fold compared to the H₂O₂-treated group. FGE directly inhibited ROS production from 13.4 to 3.6 (the fluorescence mean of DCF-DA) and also reduced apoptotic cells from 45% to 10% (Hoechst 33342 staining) at 2.5 ㎍/mL. These results demonstrate the excellent antioxidant activity of FGE and show that it can be used as a functional food to prevent liver disease.

• Journal of Oral Medicine and Pain
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• v.24 no.3
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• pp.335-345
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• 1999

법의학적 개인식별 및 친생자 감정시 여러 개의 single tandem repeats(STR) 유전좌위 검색이 필요하다. 그 이유는 STR 유전좌위는 대립유전자 수가 적고 이형접합도가 낮아 서로 다른 개체간에도 동일한 유전좌위를 가질 확률이 높기 때문에 개인식별에 대한 기여도가 떨어지게 된다. 따라서 여러 개의 다양한 STR 유전좌위들을 동시에 분석함으로써 우연적으로 개체간에 유전자형이 일치할 가능성을 낮추어야 감정의 신뢰성을 높일 수 있으며 이에는 각 STR 유전좌위에 대한 유전좌위의 분포가 인종별, 지역별로 달라 이에 대한 유전자분포를 구하는 것이 선행조건이다. 이에 본 연구에서는 법의학적 개인식별 및 친자감정시 기초자료로 활용하기 위하여 서로 혈연관계가 없는 201명의 한국인 혈액에서 DNA를 추출하여 STR 유전좌위증 human coagulation factor XIII A subunit gene(F13A0l Locus), human c-fes/fps proto-oncogene(FESFPS Locus), human von Willebrand factor gene (vWA Locus)등 FFv Triplex 유전자를 중합효소반응에 의하여 동시에 증폭하고, 폴리아크릴아마이드겔을 이용한 전기영동 및 질산은 염색을 시행한 후 FFv Triplex유전자의 유전자형 및 대립유전자 빈도 등을 분석하여 다음과 같은 결과를 얻었다. (1) F13A01유전자는 5개의 대립유전자, 12개의 유전자형을 검출하였으며, 이형접합도는 60.7%로 나타났고 대립유전자 및 유전자빈도는 3.2, 4, 5, 6, 16 대립유전자에서 각각 0.34 3, 0.114, 0.062, 0.475, 0.005로 나타났으며, 대립유전자 7, 8, 9, 10, 11, 12, 13, 14, 15는 검출되지 않았다. (2) F13A01 대립유전자다양성 (allelic diversity value)은 0.641, 개인식별력(PD)은 0.814를 보였으며 대립유전자다양성 및 이형접합도가 다른 민족과 비교할 때 다소 낮았다. (3) FESFPS유전자는 8개 대립유전자 모두 나타났으며, 15개의 유전자형을 검출하였으며, 이형접합도는 66.7%로 나타났고 대립유전자 및 유전자빈도는 7, 8, 9, 10, 11, 11, 12, 13, 14 대립유전자에서 각각 0.002, 0.002, 0.005, 0.032, 0.507, 0.264, 0.197, 0.007로 나나났다. (4) FESFPS 대립유전자다양성(allelic diversity value)은 0.641, 개인식별력(PD)은 0.804를 보였다. (5) vWA유전자는 9개의 대립유전자, 23개의 유전자형을 검출하였으며, 이형접합도는 80.1%로 나타났고 대립유전자 및 유전자 빈도는 11, 12, 14, 15, 16, 17, 18, 19, 20 대립유전자 에서 각각 0.002, 0.002, 0.219, 0.032, 0.187, 0.279, 0.189, 0.072, 0.017로 나타났으며, 대립 유전자 13, 21는 검출되지 않았다. (6) vWA 대립유전자다양성(allelic diversity value)은 0.799, 개인식별력(PD)은 0.924로 매우 높게 나타냈다.

• Nuclear Engineering and Technology
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• v.30 no.2
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• pp.99-111
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• 1998

Chemical composition of the insoluble residue in a simulated spent PWR fuel(SIMRJEL) were studied. SIMFUELS were prepared by adding calculated amount of FP(fission product) elements with a burnup of 3.6% FIMA(fission per initial metal atom) to uranium in nitrate solution, evaporating the mixed solution to dryness, calcining at 90$0^{\circ}C$ in a stream of 4% H$_2$ + 96% He, and heating the pellet at 140$0^{\circ}C$ under high and low oxygen potentials. Insoluble residue was obtained from the dissolution of the SIMFUEL with HNO$_3$(1 : 1). The chemical composition of the SIMFUELs and the insoluble residues was determined by EPMA(electron probe microanalysis), XPS(X-ray photoelectron spectroscopy) and by XRD (X-ray diffraction) measurements. All of the insoluble residues suspended and precipitated were composed mainly of Mo, Ru with a small amount of Zr, Rh, Pd and Cd. The amount of insoluble residue(<1 wt.%) and a Mo/Ru ratio decreased with increasing oxygen potential. Formation of the zirconium molybdate precipitate, ZrMo$_2$O$_{7}$(OH)$_2$($H_2O$)$_2$, was observed in the residues. The possible role of Mo on the phase formation was discussed in regard to oxygen potential.l.