• Journal of the Korean Crystal Growth and Crystal Technology
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• v.17 no.5
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• pp.179-186
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• 2007

Single crystal $CdGa_2Se_4$ layers were grown on a thoroughly etched semi-insulating GaAs(100) substrate at $420^{\circ}C$ with the hot wall epitaxy(HWE) system by evaporating the polycrystal source of $CdGa_2Se_4$ at $630^{\circ}C$. The crystalline structure of the single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction(DCXD). The carrier density and mobility of single crystal $CdGa_2Se_4$ thin films measured with Hall effect by van der Pauw method are $8.27{\times}10^{17}cm^{-3},\;345cm^2/V{\cdot}s$ at 293 K, respectively. The photocurrent and the absorption spectra of $CdGa_2Se_4/SI$(Semi-Insulated) GaAs(100) are measured ranging from 293 K to 10 K. The temperature dependence of the energy band gap of the $CdGa_2Se_4$ obtained from the absorption spectra was well described by the Varshni's relation $E_g(T)=2.6400eV-(7.721{\times}10^{-4}eV/K)T^2/(T+399K)$. Using the photocurrent spectra and the Hopfield quasicubic model, the crystal field energy(${\Delta}cr$) and the spin-orbit splitting energy(${\Delta}so$) far the valence band of the $CdGa_2Se_4$ have been estimated to be 106.5 meV and 418.9 meV at 10 K, respectively. The three photocurrent peaks observed at 10 K are ascribed to the $A_{1^-},\;B_{1^-},\;and\;C_{11}-exciton$ peaks.

• Parasites, Hosts and Diseases
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• v.32 no.1
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• pp.19-26
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• 1994

An in uipo culturing to examine the cyst stage of ToxopLQsma gondii (ME49 strain) was Investigated using murine peritoneal macrophages, and we also examined the effect of CAMP or DHFR Inhibitors on the growth of bradyzoltes. For experiments ICR mice were Injected 1.p. with 1,500 brain cysts. At 1, 3, 5 and 7 days, peritoneal exudates were Isolated and then adherent peritoneal macrophages were cultured for 1,3,5 and 10 days. Growth pattern of bradyzoltes was measured by (3H)-uracil uptake assay and morphological pattern of pseudocysts formed in macrophages was observed Uth Glemsa stain. Mostly bradyzoites were observed In the macrophages extracted at 3 and S days post Infection. After 3 days in vitro, a number of pseudocysts were formed in the macrophages and the size of pseudocysts was increased during further 5 and 10 days in vitro culture. CAMP stimulated the growth of bradyzoltes when in uiuo 3 and 5 days and then in vitro 5 and 10 days conditions were applied. In case of.DHFR Inhibitors, pynmethamlne produced a linearly decremental effect with a cont.-dependent mode but methotrexate was not effective against Intracellular bradyzoltes or pseudocysts In this system. It was suggested that cyst-forming strain of T gondii (ME49 strain) could be maintained and cultivated in uitro by use of murine peritoneal macrophages. In uivo 3 and 5 days and then in uiko 5 and 10 days conditions appeared to be suitable for culturing of bradyzoltes. CAMP and pyrimethamine had an effect of stimulation and inhibition on the growth of bradyzolte, respectively.

• Nuclear Engineering and Technology
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• v.56 no.8
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• pp.3335-3346
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• 2024

Due to the radiation released by commonly used isotopes, many nuclear, medical, and industrial facilities require proper radiation shielding. In this work, distinct copper borate glasses intercalated with varied aluminum and vanadium oxide (Al₂O₃ and V₂O₅) content have been synthesized and used against radiation (gamma rays and fast/thermal neutrons). The different percents were as follows: [60% B₂O₃ + 35% CuO + (5-x)% Al₂O₃ + xV₂O₅], where x = 0, 1, and 2.5 wt.%, which was coded as BCu(5-x)Al:xV. The synthesized glass samples were characterized using Fourier transforms, infrared, and X-Raydiffraction analysis. Experimentally, the radiation shielding possessions of the samples were established using an HPGe detector at the gamma energy lines 0.356 MeV, 0.661 MeV, 1.173 MeV, and 1.332 MeV. Also, the prepared glasses were investigated theoretically using the Monte Carlo code (MCNP5) at photon energies of 0.015-15 MeV. Also, the fast and thermal neutron macroscopic effective removal cross-sections were calculated using MRCsC and JANIS-4.1 software, respectively. The prepared sample BCu2.5Al:2.5V, which has a vanadium and aluminum content of 2.5%, has the highest linear attenuation coefficient as well as the highest removal cross-section for fast, and thermal neutrons.

• Korean Journal of Plant Tissue Culture
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• v.24 no.2
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• pp.103-106
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• 1997

In order to establish a micropropagation system of Naricissus, the ability of bulblet regeneration among propagation materials was compared, and the adequate growth regulators and concentrations for each cultivar were investigated. The inorganic components were also assayed in the parts of propagation materials. In propagation materials, scape with based plates showed hightest rate of bulblet formation and rapid growth of formed bulblets in vitro, comparing to other parts of it. In comparing of varieties, 'Dutch Master' and 'Golden Harvest' showed a high ability for bulblet regeneration. The ability of bulblet regeneration was most favorable in the medium, supplemented with 5.0 mg/L BA and 2.5 mg/L NAA in 'Dutch Master', and 5.0 mg/L BA and 1.0mg/L NAA in 'Golden Harvest', respectively. In inorganic component analysis of propagation materials, the White part of scape contained 1.18 mg/L$P_2O_5$, 2.57 me Ca, 0.94 me Mg and 3.20 mg/L total N. It showed higher levels in concentration of inorganic components as compared to those of the other part of scape. In addition, leaves and yellow part of scape contained significantly high levels of Ca and Mg while scales bulb showed considerably low levels in all inorganic compounds.

• Proceedings of the Materials Research Society of Korea Conference
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• 2009.05a
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• pp.30.1-30.1
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• 2009

PZT(Pb(Zr, Ti)$O_3$ 압전세라믹스는 뛰어난 압전 특성과 강유전 특성을 가지고 있어서 현재 널리 사용되고 있다. 하지만 PZT세라믹스는 큐리온도 이상에서 그 특성을 잃게 되고 높은 온도에서의 응용이 제한된다. 따라서 높은 큐리온도를 가지는 압전체를 개발하기 위한 연구가 많이 이루어지고 있다. $PbTiO_3$의 경우에는 $Bi(Zn_{0.5}Ti_{0.5})$, $BiFeO_3$등의 Bi계 세라믹스를 치환하면서 큐리온도가 올라가는 결과가 보고되고 있다. 하지만 이것은 PZT세라믹스 보다 압전 및 유전 특성이 상당히 낮다. 따라서 본 연구에서는 $(1-x)PbZrO_3-xPbTiO_3$조성에 Bi(Me)$O_3$(Me:Zn, Ti, Fe, Al)를 치환하여 압전특성 및 강유전 상전이 온도를 조사하였다. 모든 시편들은 고상반응법으로 제조하였고, 제조한 시편으로 조성에 따른 압전특성 및 유전특성의 변화를 측정하였다. 그리고 이를 통해 큐리온도는 PZT의 MPB조성근처에서 Bi계 세라믹의 치환은 $T_C$가 낮아 졌으나, Tetragonal 상을 가지고 있는 Ti-rich인 조성에서는 $T_C$가 높아지는 것을 관찰하였다.

• Journal of Microbiology and Biotechnology
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• v.29 no.7
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• pp.1137-1143
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• 2019

Hepatitis E virus (HEV) accounts for 20 million infections in humans worldwide. In most cases, the infections are self-limiting while HEV genotype 1 infection cases may lead to lethal infections in pregnant women (~ 20% fatality). The lack of small animal models has hampered detailed analysis of virus-host interactions and HEV-induced pathology. Here, by employing a recently developed culture-adapted HEV, we demonstrated that methyltransferase, a non-structural protein, strongly inhibits melanoma differentiation-associated gene 5 (MDA5)-mediated activation of type I interferon responses. Compared to uninfected controls, HEV-infected cells display significantly lower levels of $IFN-{\beta}$ promoter activation when assessed by luciferase assay and RT-PCR. HEV genome-wide screening showed that HEV-encoded methyltransferase (MeT) strongly inhibits MDA5-mediated transcriptional activation of $IFN-{\beta}$ and $NF-{\kappa}B$ in a dose-responsive manner whether or not it is expressed in the presence/absence of a tag fused to it. Taken together, current studies clearly demonstrated that HEV MeT is a novel antagonist of MDA5-mediated induction of $IFN-{\beta}$ signaling.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.223-223
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• 2006

A Suzuki-coupling route is developed for preparation of ortho-phenylene-bridged Cp/amido complexes, one of which shows higher activity, higher 1-hexene incorporation, and higher molecular weight than the silylene-bridged standard CGC $[Me_{2}Si({\eta}^{5}-Me_{4}Cp)(N^{t}Bu)]TiCl_{2}$.

• Journal of the Korean Vacuum Society
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• v.8 no.3B
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• pp.297-301
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• 1999

High quality CdTe single crystal for the solar cell fabrication was grown by vertical Bridgman method. The etch pits patterns of {111} surfaces of CdTe etched by Nakagawa solution was observed the {11} A composed of Cd atoms with typical triangle etch pits of pyramid mode. From the photoluminescence measurement of {111} A, we observed free exciton $(E_x)$ existing only high quality crystal and neutral acceptor bound exciton ($A^{\circ}$, X) having very strong peak intensity. Then, the full width at half maximum and binding energy of neutral acceptor bound exciton were 7 meV and 5.9 meV, respectively. By Haynes rule, and activation energy of impurity was 59meV. Therefore, the origins on impurity level acting as a neutral acceptor were associated Ag or Cu elements.

• Nuclear Engineering and Technology
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• v.55 no.7
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• pp.2572-2577
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• 2023

A field determination method for small D-T neutron source yield based on the oxygen prompt gamma rays was established. A neutron-gamma transport equation of the determination device was developed. Two yield field determination devices with a thickness of 20 mm and 50 mm were made. The count rates of the oxygen prompt gamma rays were calculated using three energy spectra processing approaches, which were the characteristic peak of 6.13 MeV, the overlapping peak of 6.92 MeV and 7.12 MeV, and the total energy area. The R-square of the calibration curve is better than 94% and the maximum error of the yield test is 5.21%, demonstrating that it is feasible to measure the yield of D-T neutron source by oxygen prompt gamma rays. Additionally, the results meet the requirements for field determination of the conventional D-T neutron source yield.

• Applied Biological Chemistry
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• v.45 no.1
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• pp.42-46
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• 2002

Effects of the water extract from Kalopanax pictus NAKAI on insulin-like action and glucose uptake in 3T3-L1 cells were investigated. The bark of K. pictus NAKAI was treated with hot water and the extract was freeze-dried. Total extract of K. pictus NAKAI was fractionated into 6 fractions with increasing gradients from 0 to 100% MeOH on Amberlite XDA-4. Treatment of 3T3-L1 fibroblasts with 1 ${\mu}g/ml$ and 10 ${\mu}g/ml$ of K. pictus NAKAI total extracts significantly increased the differentiation of the cells. When co-treated with inducers such a dexamethasone, 1-methyl-3-isobutylxanthine and insulin, the differentiation was increased at 1 ${\mu}g/ml$ of total extract, but not at 10 ${\mu}g/ml$. In 3T3-L1 adipocytes, glucose uptake was increased by 3.3 times with addition of 0.3 and 3 ${\mu}g/ml$ of Fr. 1 (0-10% MeOH) and Fr. 3 (30% MeOH) at 3 ng/ml insulin. In conclusion, K. pictus NAKAI contains such compounds that play a role of insulin-like action and insulin sensitizer.