• BMB Reports
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• v.41 no.11
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• pp.808-813
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• 2008

Human microsomal prostaglandin E synthase-1 (mPGES-1) is a membrane associated protein that catalyzes the conversion of prostaglandin $H_2$ ($PGH_2$) into prostaglandin $E_2$ ($PGE_2$). In this study, the expression of human mPGES-1 in E. coli was significantly enhanced by modifying the utility of specific codons and the recombinant mPGES-1 was efficiently purified to homogeneity. The $K_m$ and $V_{max}$ of the purified enzyme were determined and the trimeric state characterized by chemical cross-linking with glutaraldehyde. The purified mPGES-1 was used for the screening of a chemical library of bioactive or drug compounds to identify novel inhibitors, and oxacillin and dyphylline were identified as moderately inhibiting mPGES-1 with $I_{C50}$ values of 100 and 200 ${\mu}M$, respectively. As these compounds competitively inhibited the catalysis of $PGH_2$, their binding sites appeared to be located near the $PGH_2$ binding pocket.

• Journal of the Korean Society for Heat Treatment
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• v.23 no.2
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• pp.90-95
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• 2010

The effects of grain size on the corrosion resistance of 429EM ferritic stainless steels for automobile exhaust system were investigated. Using specimens held at maximum service temperature of $950^{\circ}C$ for 10~70 hours, electrochemical polarization tests were conducted. While corrosion current density, $I_{corr}$, was influenced little by grain size, pitting potential, $E_p$, was increased with an increase of grain size. Sensitizaton at grain boundary occurred when the specimen were held at $950^{\circ}C$ for above 50 hours because of the dissolution of precipitates and grain coarsening.

• Journal of the Korean Ceramic Society
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• v.32 no.12
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• pp.1369-1376
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• 1995

The WO3 thin-film NOx sensor which is of practical use and includes the heater and the temperature sensor was fabricated. The WO3 thin films as a gas-sensing layer was deposited at ambient temperature in a high-vacuum resistance heated evaporator. The highest sensitivity of the WO3 thin-film sensor to NOx was obtained under the condition of the annealing temperature of 50$0^{\circ}C$ and the operating temperature of 30$0^{\circ}C$. The gas sensing characteristics of this sensor was excellent, i.e. high sensitivity (Rgas/Rair in 3 ppm NO2=53) and fast response time (4 seconds).

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2002.05a
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• pp.148-151
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• 2002

본 연구에서는 Ca, In, V, Al을 첨가 원소로 사용한 YIG 페라이트 분말을 분무건조기로 준구형 과립으로 만들어 일반적인 세라믹 제조 공정 방법으로 다결정 테를 제조하였고, 소결온도와 첨가원소의 조성비에 따른 YIG 페라이트의 기본물성과 전자기적 특성 변화를 조사하였다. 제조된 YIG 페라이트에 대한 기본 물성과 자기 특성을 밀도측정기, XRD, SEM, VSM, Network Analyzer 등을 이용하여 측정 분석하였다. $Y_{2.1}$C $a_{0.9}$F $e_{4.4}$ $V_{0.5}$I $n_{0.05}$A $l_{0.05}$ $O_{12}$ 조성의 YIG 페라이트에 대한 전자기적 특성 측정 결과 13$50^{\circ}C$에서 소결한 YIG 페라이트에서 우수한 삽입손실 값과 Isolation 값을 나타내였으며 이론밀도의 92%의 높은 밀도값을 가지며 높은 포화자화(4$\pi$Ms) 값을 지닌 우수한 전자기적 특성을 나타내었다.내었다.내었다.

• Nuclear Engineering and Technology
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• v.54 no.11
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• pp.4146-4158
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• 2022

Ultra-high performance concrete (UHPC) has been widely utilized in military and civil protective structures to resist intensive loadings attributed to its excellent properties, e.g., high tensile/compressive strength, high dynamic toughness and impact resistance. At present, aiming to improve the defects of the traditional vertical concrete cask (VCC), i.e., the external storage facility of spent fuel, with normal strength concrete (NSC) shield, e.g., heavy weight and difficult to fabricate/transform, the feasibility of UHPC applied in the shield of VCC is numerically examined considering its high radiation and corrosion resistance. Firstly, the finite element (FE) analyses approach and material model parameters of NSC and UHPC are verified based on the 1/3 scaled VCC tip-over test and drop hammer test on UHPC members, respectively. Then, the refined FE model of prototypical VCC is established and utilized to examine its dynamic behaviors and damage distribution in accidental tip-over and end-drop events, in which the various influential factors, e.g., UHPC shield thickness, concrete ground thickness, and sealing methods of steel container are considered. In conclusion, by quantitatively evaluating the safety of VCC in terms of the shield damage and vibrations, it is found that adopting the 300 mm-thick UHPC shield instead of the conventional 650 mm-thick NSC shield can reduce about 1/3 of the total weight of VCC, i.e., about 50 t, and 37% floor space, as well as guarantee the structural integrity of VCC during the accidental drop simultaneously. Besides, based on the parametric analyses, the thickness of concrete ground in the VCC storage site is recommended as less than 500 mm, and the welded connection is recommended for the sealing method of steel containers.

• Journal of the Korean Society of Safety
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• v.28 no.2
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• pp.26-30
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• 2013

The purpose of this study is to find risk factors by analyzing the operation principle of a photo coupler (P/C) used to remove the noise of electronic devices and establish a base for the performance improvement of developed products. It was found from the P/C circuit analysis of normal products that they were equipped with an electrolytic condenser of $0.1{\mu}F$ to smooth system signals. Due to the epoxy resin packing the external part of the P/C, this study experienced a limit to visually examine the damage to it. It could be seen from the analysis of electric characteristics of the P/C that the forward voltage ($V_f$) and reverse current ($I_r$) were 1.3 V and 10 uA, respectively. In addition, it is required that the breakdown voltage (VCE) between the collector (C) and emitter (E) be maintained at less than 35 V. The and of the damaged product #1 were comparatively good. However, the measurement of was 100.0 uA. From this, it is thought that a short circuit occurred to the internal circuit. Moreover, from the fact that the of the damaged product #2 was open circuit and the measurement of was 0.0 uA, it is thought that the collector and emitter was separated or insulation resistance was significantly high. Furthermore, from the fact that the of the damaged product #3 was open circuit and the measurement of was 0.0 uA, it is thought that the space between the collector (C) and emitter (E) failed to meet the design standard or that they were separated. Therefore, it is thought that fabricating the P/C by increasing the reverse current 10 mA to 50 mA will prevent its malfunction.

• Korean Journal of Food Science and Technology
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• v.35 no.1
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• pp.132-137
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• 2003

Antioxidant and anti-inflammatory potentials of various grape extracts were evaluated. Extracts from Kyho seed, Kyho stem, and Campbell seed showed potent 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activities compared to resveratrol $(IC_{50}=16.9,\;21.5,\;21.9,\;34.6\;{\mu}g/mL,\;respectively)$, among which, antioxidant effect of Kyho seed extract were similar to that of vitamin C $(IC_{50}=12.2\;{\mu}g/mL)$. These extracts also exhibited inhibitory activities on lipopolysaccharide (LPS)-induced prostaglandin $E_2$ production and nitrite formation in mouse macrophage RAW 264.7 cells at $50\;{\mu}g/mL$. Kyho stem and seed extracts showed growth inhibitory activities in human lung and colon cancer cells. These results suggest the potential roles of grape extracts as antioxidants and anti-inflammatory agents.

• Journal of the Korean Society of Radiology
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• v.5 no.6
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• pp.335-341
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• 2011

This paper searched the affect of Water dropwort and Tumeric on radiation exposure. By experimenting 50 male mouse, ICR type 5 weeks old male 25~30g, 5 mouse was divided in to each group respectively. A : 3 Gy control group, B : 5 Gy control group, C : 3 Gy, FW, D : 5 Gy FW, E : 3 Gy LW, F : 5 Gy LW, G : 3 Gy FT, H : 5 Gy FT, I : 3 Gy LT, J : 5 Gy LT FW : Ate Water dropwort before the radiation exposure. FT : Ate Tumeric before the radiation exposure. LW : Ate Water dropwort after the radiation exposure. LT : Ate Tumeric after the radiation exposure. During the 7 day radiation, Control group (A, B) received physiological saline (500mg/kg/day) in oral administration, LW and LT group (E, F, I, J) respectively received Water dropwort or tumeric (500mg/kg/day) in oral administration after the radiation, FW and FT group (C, D, G, H) respectively received Water dropwort or tumeric (500mg/kg/day) in oral administration before the radiation. As a result, an average leukocyte rate on 5 mouse was 200K/${\mu}L$ on group A. 6.46K/${\mu}L$ on group C which was in normal rate range (1.8-10.7 K/${\mu}L$). An average leukocyte rate was 23.33K/${\mu}L$ on group G. which was not normal rate, but compare to 200K/${\mu}L$, it was closer to normal rate. An average lymphocyte rate was 118.87K/${\mu}L$ on Group A. 1.51K/${\mu}L$ on Group G. which was in normal lymphocyte rate range (0.9-9.3K/${\mu}L$). An average thrombocyte rate was 4000K/${\mu}L$ on Group A. 1107 K/${\mu}L$ on Group C. 2759.6 K/${\mu}L$ on Group G. which was in normal thrombocyte rate range (592-2972 K/${\mu}L$). From this result, it was found that when exposed to radiation, Water dropwort and Tumeric have defensive effect in a preventive level. Also from an animal experiment, it was found that blood corpuscle rate returns to a normal rate. Based on this experiment, diverse research on this field should be conducted.

• Journal of Chest Surgery
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• v.17 no.4
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• pp.796-803
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• 1984

Pure Red-Cell Aplasia [P.R.C.A.] is rare disease characterized by absence of erythroid precursors in the bone marrow, normocytic normochromic anemia with profound reticulocytopenia in the peripheral blood, and relatively or completely spared granulopoiesis and thrombopoiesis. The association rates of P.R.C.A. with Thymoma is approximately 50%, but only 5-10% of all patients with a Thymoma have a P.R.C.A.. P.R.C.A. is thought to be a variety of autoimmune disease, and humoral inhibitor, i.e. IgG, has been demonstrated experimentally. Its treatments such as thymectomy, immunosuppressants, steroid, androgenic hormone, and splenectomy have been tried but the result is not satisfactory and the prognosis is poor. We experienced a case of P.R.C.A. with Thymoma treated with thymectomy and postoperative steroid therapy, and which showed good postoperative recovery clinically and hematologically.

• The Journal of Pediatrics of Korean Medicine
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• v.13 no.1
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• pp.253-275
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• 1999

The effects of Sagunjatang and Samultang on the immunosuppression induced by methotrexate(MTX) in rats were investigated in this study. The multiple parameters of immunity assessed in each rats included leukocyte count, lymphocyte rate, the number of lymphocyte in tibial bone marrow, contact hypersensitivity to DNFB, morphological change of thymocyte and IgG antibody on SDS-PAGE. Sprague-Dawley male rats were used and divided into five groups at random. Group A was normal control. Group B, the MTX treatment control, was injected i.v. with 2mg/kg of on days 9, 11 after sensitization with SRBC on 5th day. Group C, the experimental control, was treated Sagunjatang for 18days and MTX. Group D was treated Samultang for 18days and MTX. Group E was treated Sagunjatang-Samultang for 18days and MTX. The dosage of Sagunjatang and Samultang was $1m{\ell}/day$ respectively. In the case of Group E, rats Were fed Sagunjatang $1m{\ell}$ in the morning and Samultang $1m{\ell}$ in the afternoon. The results are summarized as follows: 1. Leukocyte count in rats induced by intravenous sensitization with SRBC was decreased significantly in Group E. 2. Leukocyte counts of 2weeks later after being treated MTX were increased significantly in Groups C and D. 3. Lymphocyte rate in rats induced by intravenous sensitization with SRBC wasn't changed significantly in all the experimental groups. 4. Lymphocyte rate of 2weeks. later after being treated MTX was increased significantly in Group D. 5. The number of lymphocyte in tibial bone marrow was incereased significantly in Group C. 6. Contact hypersensitivity wasn't changed significantly in all the experimental groups. 7. Morphological finding of thymocyte in group C was similar to normal group as compared with control group. 8. Purified IgG of all the experimental groups showed two bands of 50,000 and 25,000 on SDS-PAGE. But there was no difference among experimental groups.