• Journal of Sensor Science and Technology
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• v.9 no.5
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• pp.341-349
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• 2000

CsI(Br) single crystals doped with 1, 3, 5 or 10 mole% $Br^-$ ions, as an activator, were grown by Czochralski method. The lattice structure of grown CsI(Br) single crystal was bcc and its lattice constant was $4.568\;{\AA}$. The absorption edge of the CsI(Br) single crystals was observed at 243 nm. The spectral range of the luminescence excited by 243 nm of wavelength was $300{\sim}600\;nm$, and its peak emission appeared at 440 nm. The luminescence intensity was maximum when CsI(Br) was doped with 3 mole % $Br^-$ ions. The energy resolutions of the CsI(Br) scintillator doped with 3 mole % $Br^-$ ions were 15.0% for $^{137}Cs$(662 keV), 13.1% for $^{54}Mn$(835 keV), and 18.0% and 6.3% for $^{22}Na$(511 keV and 1275 keV), respectively. The decay curves had fast and slow components, and the fast component was about 41 ns independent on the concentration of the $Br^-$ ions. The time resolution of CsI(Br) scintillators decreased with increasing of the concentration of $Br^-$ ions.

• Nuclear Engineering and Technology
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• v.54 no.5
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• pp.1597-1605
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• 2022

A porous silica-based adsorbent was prepared by impregnating the pores of a silica support with the extractant 1,3-[(2,4-diethylheptylethoxy)oxy]-2,4-crown-6-calix[4]arene (Calix[4]arene-R14) and an additive agent 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (C₂mim ⁺ NTf^-₂) as the materials to remove cesium(I) (Cs⁺) ions from seawater. The as-prepared adsorbent showed excellent adsorption performance toward Cs⁺ ions, with adsorption equilibrium reached within 2 h and an adsorption amount of 0.196 mmol/g observed. The solution pH, temperature, and the presence of coexisting metal ions were found to have almost no effect on Cs⁺ adsorption. The adsorption mechanism was considered to proceed via ion exchange between Cs⁺ and C₂mim⁺. In addition, the particle-induced X-ray emission analysis results further clarified that the adsorbed Cs⁺ ion species on the adsorbent was in the form of both CsCl and CsBr.

• Korean Journal of Medicinal Crop Science
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• v.15 no.6
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• pp.444-450
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• 2007

Dried leaves from Cedrela sinensis A. Juss. (CS), have been observed to possess various pharmacological activity and contain various antioxidant constituents. The protective effect of ethanol extract of CS on hydrogen peroxide $(H_2O_2)-induced$ neurotoxicity was examined using primary cultured rat cortical neurons in the present study. Exposure of cultured neurons to 100 ${\mu}M\;H_2O_2$ caused a significant neuronal death as assessed by a 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide (MTT) assay and Hoechst 33342 staining. The addition of CS, over a concentration range of 10 to $50{\mu}g/m{\ell}$, concentration-dependently prevented the $H_2O_2-induced$ neuronal apoptotic death. CS $(50{\mu}g/m{\ell})$ significantly inhibited $H_2O_2-induced$ elevation of the cytosolic $Ca^{2+}$ concentration $([Ca^{2+}]_c)$, which was measured by a fluorescent dye, Fluo-4 AM. CS (30 and $50{\mu}g/m{\ell})$ inhibited glutamate release and generation of reactive oxygen species (ROS) induced by $100{\mu}M\;H_2O_2$. These results suggest that CS may mitigate the $H_2O_2-induced$ neurotoxiciy by interfering with the increase of $[Ca^{2+}]_c$, and then inhibiting glutamate release and generation of ROS in cultured neurons.

• Journal of Periodontal and Implant Science
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• v.33 no.4
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• pp.643-650
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• 2003

Cyclosporin-A(CsA)는 장기와 조직 이식에 따른 거부반응을 조절하기 위해 사용되는 면역억제제로, 이식의학의 발달과 더불어 사용량이 증가하고 있다. CsA의 부작용중의 하나인 치은과증식은 30-50%의 빈도로 발발하고 있다. 최근 macrolide 계열의 항생제인 azithromycin을 이용하여 이런 부작용을 억제시킨다는 임상 보고가 있어서, 이를 실험적으로 확인하고자 하였다. 이를 위해 CsA를 투여한 적이 없는 환자에서 정상 치은조직을 채취, 치은섬유아세포를 배양하였다. 우선 CsA에 대한 치은섬유아세포의 반응을 보기 위해 다양한 농도($10^{-8}-10^{-10}$g/ml)로 처치하여, 세포 증식량과 교원질 합성량을 MTT assay와 Sirol Collagen Assay를 이용하여 측정하였다. 이에 반응을 보인 조건과 세포를 대상으로 다양한 농도($10^{-8}-10^{-10}$g/ml)의 azithromycin을 CsA와 동시 처치하여 아래와 같은 결과를 얻었다. 1. CsA는 일부 치은섬유모세포의 증식을 증가시켰다. 그러나 Collagen 합성능에는 변화를 주지 않았다. 2. Azithromycin은 정상 치은섬유아세포의 증식능에 영향을 미치지 않았다. 3. Azithromycin은 CsA 에 반응을 보인 세포의 증식을 감소시켰으며, 이는 정상 수준과 유사하였다. 이상의 결과에서 azithromycin이 CsA에 의한 치은과증식 치료에 유익하다고 사료된다.

• Journal of Mushroom
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• v.6 no.3_4
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• pp.138-145
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• 2008

A Gram-positive, endospore-forming, rod-shaped bacterial strain was isolated from spent mushroom (Pleurotus eryngii) substrates taken from the Hoamfarm located in Keyollgnam, Korea. The isolate, designated CS9, was facultatively anaerobic, motile rod and produced xylanase. The strain grew optimally at $40^{\circ}C$ and pH 6.0. The major cellular fatty acids were anteiso-$C_{15:0}$, anteiso-$C_{17:0}$, and iso-$C_{17:0}$. The genomic DNA G+C content was 45 mol%. Comparative 16S-rDNA sequence analysis showed that the isolate CS9 formed a distinct phyletic line within the genus Bacillus and was most closely related to Bacillus subtilis YB1, with 16S DNA sequence similarity of 96.8%. Sequence similarities to other type strains were 92-94%. On the based of physiological and molecular properties, the isolate CS9 was classified within the genus Bacillus as Bacillus subtilis CS9.

• Economic and Environmental Geology
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• v.51 no.2
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• pp.99-111
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• 2018

In this study three target radionuclides ($^{60}Co$, $^{137}Cs$, and $^{125}Sb$) were reacted with solid samples collected from the nuclear facility sites to investigate their sorption and mobility behaviors for preparing unexpected nuclear accidents. The highest sorption distribution coefficients ($K_{ds}$) of target radionuclides ($^{60}Co=947mL/g$, $^{137}Cs=2105mL/g$, $^{125}Sb=81.3mL/g$) were found in topsoil layer under groundwater condition, and the $K_d$ values of three radionuclides decreased in the order of fractured rock and bedrock samples under the same groundwater condition. High $K_d$ values of $^{60}Co$ in topsoil layer and fracture rock resulted from the clay minerals present, and the $K_d$ values decreased 58-69 % under seawater condition due to high ionic strength. $^{137}Cs$ sorption was controlled by the ion exchange reaction with $K^+$ on flayed edge sites (FES) of mica. The $^{137}Cs$ sorption was the most affected by seawater (89-97 % decrease), while $^{125}Sb$ sorption was not much affected by seawater. As the results of column and batch experiments, the retardation factors (R) of $^{137}Cs$, $^{60}Co$, and $^{125}Sb$ were determined about 5400-7400, 2000-2500, and 250-415, respectively, indicating no significant transport for these radionuclides even in fractured zone with groundwater. These results suggest that even in the case of severe nuclear accident at the nuclear facilities the mobility of released radionuclides ($^{60}Co$, $^{137}Cs$, and $^{125}Sb$) can be significantly retarded by the topsoil layer and fractured rock. In addition, the results of this study will be used for the safety and environmental performance assessment of nuclear facilities.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.7
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• pp.385-390
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• 2017

This study investigated removal characteristic of soluble Cs in water by RPT (Radioactivity pollutant treatment) with coagulation and sedimentation. The RPT conducted with various chemical and natural coagulants to remove the soluble Cs which consisted pre-adsorption, Sedimentation and post-adsorption. Natural absorbent included Illite and zeolite. Especially, Illite divided LPI (Large Particle Illite) and SPI (Small Particle Illite) by grain size. Also, Chemical coagulants included high basicity PAC (poly aluminum chloride). The adsorbent had a plate structure mainly composed of quartz, albite and muscovite. The surface area were $4.201m^2/g$ and $4.227m^2/g$ and the particle sizes were $197.4-840.9{\mu}m$ and $3.28-53.57{\mu}m$, respectively. The adsorption efficiency of the natural Illite was 82.8% for LPI and 85.6% for SPI. The removal efficiency of turbidity, which was an indirect indicator of adsorbent recovery, was 96.4% and 98.3%, respectively.

• Clean Technology
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• v.24 no.3
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• pp.183-189
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• 2018

Hollow carbon spheres (HCS) and carbon spheres (CS) were prepared by a hydrothermal reaction and they were introduced as a substrate for the deposition of $MnO_2$ nanoparticles. The $MnO_2$ nanoparticles were deposited on the carbon surface by a chemical redox deposition method. After deposition, the $MnO_2$ nanoparticles were uniformally distributed on the carbon surface in a slit-shape, and sparse $MnO_2$ slits appeared on the HCS surface. The $MnO_2-HCS$ showed an initial specific capacitance of $164.1F\;g^{-1}$ at scan rate of $20mv\;s^{-1}$, and after 1,000 cycles, the specific capacitance was maintained to $141.3F\;g^{-1}$. The capacity retention of $MnO_2-HCS$ and $MnO_2-CS$ were calculated to 86% and 78% in the cycle performance test up to 1,000 cycles, respectively. $MnO_2-HCS$ showed a good cycle stability due to the mesoporous hollow structure which can cause a faster diffusion of the electrolyte and can easily adsorb and desorb $Na^+$ ions on the surface of the electrode.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.3
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• pp.380-388
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• 2005

Lipid characteristics of 6 species of fish frame (armored weasel-fish, AW; chum salmon, CS; spanish mackerel, SM; common mackerel, CM; conger eel, CE and skipjack tuna, ST) were studied by determining total lipid (TL) contents, lipid classes, and fatty acid composition. The highest yield of bone was obtained from ST frame (64.2%), followed by CS frame (57.9%), CE frame (54.6%), A W frame (41.6%), SM frame (41.7%), and CM frame (32.6%). The highest neutral lipid content was also found in total lipid (TL) from SM bone (23.3 g/100 g), followed by TL from CE bone (21.5 g/100 g), CS bone (16.0 g/100 g), and CM bone (15.5 g/100 g), while those from ST and A W bones were 7.2 g/100 g and 0.4 g/100 g, respectively. The prominent lipid classes of neutral lipids (NL) from all fish bones and muscles were triglyceride (TG), however, which was much lower in AW than in other fishes. The percentages of EPA and DHA in NL from fish bone were in the descending order of CS (29.3%), ST (27.1%), AW (27.0%), CM (25.7%), SM (21.6%), and CE (14.9%). Based on the lipid characteristics, the CS frame was the best resource for extraction of a functional lipid.

• Journal of the Korean Chemical Society
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• v.66 no.2
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• pp.78-85
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• 2022

Natural white clay was treated with 6 M of H₂SO₄ and heated at 80℃ for 6 h under mechanical stirring and the resulting acid active clay was used as an adsorbent for the removal of Cs⁺ in water. The physicochemical changes of natural white clay and acid active clay were observed by X-ray Fluorescence Spectrometry (XRF), BET Surface Area Analyser and Energy Dispersive X-line Spectrometer (EDX). While activating natural white clay with acid, the part of Al₂O₃, CaO, MgO, SO₃ and Fe₂O₃ was dissolved firstly from the crystal lattice, which bring about the increase in the specific surface area and the pore volume as well as active sites. The specific surface area and the pore volume of acid active clay were roughly twice as high compared with natural white clay. The adsorption of Cs⁺ on acid active clay was increased rapidly within 1 min and reached equilibrium at 60 min. At 25 mg L^- of Cs⁺ concentration, 96.88% of adsorption capacity was accomplished by acid active clay. The adsorption data of Cs⁺ were fitted to the adsorption isotherm and kinetic models. It was found that Langmuir isotherm was described well to the adsorption behavior of Cs⁺ on acid active clay rather than Freundlich isotherm. For adsorption Cs⁺ on acid active clay, the Langmuir isotherm coefficients, Q, was found to be 10.52 mg g^-1. In acid active clay/water system, the pseudo-second-order kinetic model was more suitable for adsorption of Cs⁺ than the pseudo-first-order kinetic model owing to the higher correlation coefficient R² and the more proximity value of the experimental value q_e,exp and the calculated value q_e,cal. The overall results of study showed that acid active clay could be used as an efficient adsorbent for the removal of Cs⁺ from water.