• Bulletin of the Korean Chemical Society
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• v.31 no.9
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• pp.2547-2552
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• 2010

CdS nano-particulate films were prepared at the air/water interface under Langmuir monolayers of arachidic acid (AA) via interfacial reaction between $Cd^{2+}$ ions in the subphase and $H_2S$ molecules in the gaseous phase. The films were made up of fine CdS nanoparticles with hexagonal Wurtzite crystal structure after reaction. It was revealed that the formation of CdS nano-particulate films depends largely on the experimental conditions. When the films were ripened at room temperature or an increased temperature ($60^{\circ}C$) for one day, numerous holes were appeared due to the dissolution of smaller nanoparticles and the growth of bigger nanoparticles with an improved crystallinity. When the films were ripened further, CdS rodlike nanoparticles with cubic zinc blende crystal structure appeared due to the re-nucleation and growth of CdS nanoparticles at the stacking faults and defect structures of the hexagonal CdS grains. These structures were characterized by transmission electron microscopy (TEM), high-resolution TEM (HRTEM), and X-ray diffraction (XRD). These results declare that CdS semiconductor nanoparticles formed at the air/water interface change their morphologies and crystal structures during the ripening process due to dissolution and recrystallization of the particles.

• Microbiology and Biotechnology Letters
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• v.30 no.4
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• pp.293-297
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• 2002

The cyclodextrin glucanotransferase (CGTase) gene from Bacillus stearothermophilus NO2 was expressed in Saccharomyces cerevisiae 2805 under the adhl promoter. The CGTase was purified from S. cerevisiae 2805/pVT-CGTS. The purified enzyme exhibited a optima of activity around pH 7.0 and $65^{\circ}C$. Thermal stability of the enzyme was increased fairly as compared with the CGTase of B. stearothermophilus NO2. The conversion yield of cyclodextrin (CD) and the production ratio of $\alpha$-, $\beta$,-, ${\gamma}$-CD from starch were showed similarly aspect to the CGTase of B. stearothermophilus NO2.

• Bulletin of the Korean Chemical Society
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• v.31 no.6
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• pp.1479-1484
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• 2010

Photosynthesis uses light energy to drive the oxidation of water at an oxygen-evolving catalytic site within photosystem II (PSII). Chlorophyll binding by the photosystem II subunit S protein, PsbS, was found to be necessary for energy-dependent quenching (qE), the major energy-dependent component of non-photochemical quenching (NPQ) in Arabidopsis thaliana. It is proposed that PsbS acts as a trigger of the conformational change that leads to the establishment of nonphotochemical quenching. However, the exact structure and function of PsbS in PSII are still unknown. Here, we clone and express the recombinant PsbS gene from Arabidopsis thaliana in E. coli and purify the resulting homogeneous protein. We used various biochemical and biophysical techniques to elucidate PsbS structure and function, including circular dichroism (CD), fluorescence, and DSC. The protein shows optimal stability at $4^{\circ}C$ and pH 7.5. The CD spectra of PsbS show that the conformational changes of the protein were strongly dependent on pH conditions. The CD curve for PsbS at pH 10.5 curve had the deepest negative peak and the peak of PsbS at pH 4.5 was the least negative. The fluorescence emission spectrum of the purified PsbS protein was also measured, and the ${\lambda}_{max}$ was found to be at 328 nm. PsbS revealed some structural changes under varying temperature and oxygen gas condition.

• IMMUNE NETWORK
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• v.10 no.5
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• pp.164-172
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• 2010

Background: We tested the hypothesis that dengue haemorrhagic fever (DHF) is associated with a $T_H1$-skewed immune response as opposed to dengue fever (DF). Methods: We estimated intracellular (in T-cells) and serum levels of designate $T_H1/T_H2$ cytokines [interferon-${\gamma}$ (IFN-${\gamma}$), interleukin-4 (IL-4), and tumor necrosis factor-${\alpha}$] and macrophage inflammatory protein-$1{\alpha}$ (MIP-$1{\alpha}$) at admission, 48h, and day 5 in 20 adults with dengue (DF=10, DHF=10) and 10 dengue-naive healthy controls. Results: At admission, intracellular IFN-${\gamma}$/IL-4 ratio in CD4+ T-cells and proportion of MIP-$1{\alpha}$-positive CD8+ T-cells were significantly higher in patients with DHF [7.21 (5.36~10.81) vs. 3.04 (1.75~4.02); p=0.011 and 6.2% (3.2~8.2%) vs. 2.4% (2.0~3.6%); p=0.023]. The latter showed a significant positive correlation with IFN-${\gamma}$/IL-4 ratio in CD4+ T-cells (Spearman's rho=0.64; p=0.003), percentage-change in haematocrit (rho=0.47; p=0.048), and serum alanine amino-transferase level (rho=0.61; p=0.009). Conclusion: We conclude that DHF is associated with a $T_H1$-skewed immune response. Further, MIP-$1{\alpha}$ in CD8+ T-cells is an important immunologic correlate of disease severity in dengue.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.9
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• pp.121-127
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• 1995

We have analyzed the double insulating layer consisting of anodic oxide and ZnS through TEM experiments. The use of double insulating layer for HgCdTe surface passivation is one of the promising passivation method which has been recently studied deeply and the double insulating layer is formed by the evaporation of ZnS on the top of anodic oxide layer grown in H$_{2}$O$_{2}$ electrolyte. The structure of anodic oxide layer on HgCdTe is amorphous but the structure of oxide layer after the evaporation of ZnS has been changed to micro-crystalline. The interface layer of 150.angs. thickness has been found between ZnS and anodic oxide layer and is estimated to be ZnO layer. The results of analysis on the chemical components of ZnS, the interface layer and anodic oxide layer have showed that Zn has diffused into the anodic oxide layer deeply while Hg has been significantly decreased from HgCdTe bulk to the top of oxide layer. The formation of ZnO interface layer and the change of structure of anodic oxide layer after the evaporation of ZnS are estimated to be defects or to induce the defects which might possibly affect the increase of the positive fixed charges shown in C-V measurements of HgCdTe MIS.

• Food Science and Preservation
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• v.30 no.5
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• pp.797-810
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• 2023

Elaeagnus umbellata leaves have been reported to suppress inflammation, allergic responses, lung cancer proliferation and oral bacterial growth. Cadmium (Cd) is a heavy metal that has been found to cause many toxicities, including liver toxicity. The aim of this study was to evaluate the capacity of 70% ethanol extract of E. umbellata leaves (EUL) to protect human hepatocytes from Cd toxicity. After exposure of HepG2 cells to Cd at 10 𝜇M for 24 h, cell viability, expression levels of apoptosis- and antioxidant-related proteins, reactive oxygen species (ROS) accumulation and Cd uptake were assessed. EUL protected HepG2 cells from Cd-induced apoptosis as determined by MTT assay. A decrease in caspase-3 and p-p53 protein levels was observed in cells pretreated with EUL prior to Cd exposure. Furthermore, the Cd-induced increase in intracellular DCF fluorescence was attenuated by EUL, indicating that the Cd-induced apoptosis preventing effect was associated with the suppression of ROS accumulation. Moreover, EUL's effects on the inhibition of p38, JNK, and AKT phosphorylation also appear to be associated with protection against Cd toxicity. Moreover, EUL upregulated Cd-depressed expression of Nrf2, HO-1, catalase, and MT-1,2 proteins, suggesting that Cd uptake-induced apoptosis in HepG2 cells may be inhibited by EUL's antioxidative potential.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2018.05a
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• pp.57-57
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• 2018

The electrorefining process is generally composed of two recovery steps in pyroprocessing - the deposit of uranium onto a solid cathode and the recovery of the remaining uranium and TRU elements simultaneously by a liquid cadmium cathode. The liquid cathode processing is necessary to separate cadmium from the actinide elements since the actinide deposits are dissolved or precipitated in a liquid cathode. Distillation process was employed for the cathode processing. It is very important to avoid a splattering of cadmium during evaporation due to the high vapor pressure. In this study, a multi-layer porous round cover was proposed and examined to develop a splatter shield for the Cd distillation crucible. Cadmium vapor can be released through the holes of the shield, whereas liquid drops can be collected in the multiple hemisphere. The collected drops flow on the round surface of the cover and flow down into the crucible. The crucible cover was fabricated and tested in the Cd distiller. The cover was made with three stainless steel round plates with a diameter of 33.50 mm. The distance between the hemispheres and the diameter of the holes are 10 and 1 mm, respectively. About 40 grams of Cd and about 4 grams of Bi was distilled at a reduced pressure for two hours at $470^{\circ}C$. After the Cd distillation experiment, cadmium was not detected and more than 90 % of Bi remained in the ICP-OES analysis. Therefore the crucible cover can be a candidate for the splatter shield of the Cd distillation crucible. Further development of the crucible cover is necessary for the decision of the optimum cover geometry and the operating conditions of the Cd distiller.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.5
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• pp.1330-1334
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• 2003

Astragali Radix(AR), one of the strong tonic herbs, is known to improve immunological responses in mice and human. In this study, AR's ai-reinforcing effect was examined in the context of CD4/sup +/ T cells' TCR/CD3 induced activation responses. In order to evaluate the direct effect of AR on helper T cells, CD4/sup +/ T cells are isolated using magnetic bead and their proliferation and CD69 expression in AR treated medium were assessed with anti-CD3/anti-CD28 activation for 48h. CD4 T cells' proliferation was slightly increased but there was little effect on CD69 expression. RT PCR and ELISA equally demonstrated that IL-2 and IL-4 production was increased but IFN-ν was down-regulated. This shows AR ethanol extract favors Th2 cytokine profile under neutral conditions.

• Journal of Sensor Science and Technology
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• v.2 no.1
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• pp.109-115
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• 1993

A CdS single crystal was grown by using sublimation method. Lattice constants, $a_{o}$ and $c_{o}$, obtained by using extrapolation were $4.131{\underline{8}}{\AA}$ and $6.712{\underline{2}}{\AA}$, respectively. The carrier density was${\sim}10^{23}m^{-3}$ and the mobility was $2.93{\times}10^{-2}m^{2}$/V sec from measured Hall data at room temperature. The mobility has a increasing tendency in proportion to $T^{1/2}$ from 33 K to 150 K and a decreasing tendency in proportion to $T^{-2}$ from 180 K to room temperature. The short wavelength band peak measured from photocurrent was due to intrinsic transition, and the energy value of this peak was equal to the energy band gap of CdS photoconductor.

• Korean Journal of Materials Research
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• v.7 no.7
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• pp.618-622
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• 1997

상온에서 측정한 Cd$_{x}$Ni$_{1-x}$Fe$_{2}$O$_{4}$의 Mossbauer 스펙트럼은 조성비에 따라 x값이 0.4이하인 시료에서는 준강자성에 의한 여섯개의 공명 흡수선, x값이 0.5인 시료에서는 이완된 형태의 공명흡수선, 그리고 x값이 0.6시료인 상자성에 의한 두개의 공명 흡수선이 나타났다. Cd$_{x}$Ni$_{1-x}$Fe$_{2}$O$_{4}$의 x값이 0.4이하인 시료의 초미세 자기장(H$_{hf}$)과 x값이 0.6 이상인 시료의 사중극자 분열치 (Q.S.)는 Cd농도가 증가함에 따라 감소한다. 시료의자기적 성질에 따른 이성질체 이동치(I.S.)의 차이는 있으나, Ni와 Cd이온의 농도에 따른 뚜렷한 의존성은 나타나지 않았다.다.