• Bulletin of the Korean Chemical Society
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• v.31 no.1
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• pp.27-30
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• 2010

A series of thioureas were synthesized as inhibitors of NO production in lipopolysaccharide-activated macrophages. We investigated the effect of lipophilic moiety and N-substituents of the thioureas on the activity. Phenoxazine and carbazole-containing derivatives revealed higher activity than indole-containing thioureas. The appropriate spacer between lipophilic tail and thiourea head and methyl substituent at N3 position of thiourea brought beneficial effect on the inhibition of NO production. Among prepared compounds, phenoxazine-containing derivative 2a was the most potent with $2.32 {\mu}M$ of $IC_{50}$ value. RT-PCR analysis suggested that the prepared thioureas inhibited NO production through the suppression of iNOS mRNA expression.

• Bulletin of the Korean Chemical Society
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• v.34 no.10
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• pp.3073-3082
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• 2013

Designed and synthesized twenty-four 2,4-diaryl benzofuro[3,2-b]pyridine derivatives were evaluated for topoisomerase I and II inhibitory activities as well as cytotoxicities against several human cancer cell lines. Various aryl groups such as phenyl, 2- or 3- furyl, 2- or 3-thienyl, and 2-pyridyl were substituted at 2- or 4- position of central pyridine. Compounds 8, 12, 13, and 14, with 2-furyl either at 2- or 4- position of central pyridine showed the significant topoisomerase II inhibitory activity at 100 ${\mu}M$.

• Bulletin of the Korean Chemical Society
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• v.34 no.4
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• pp.1077-1080
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• 2013

Fluorinated polymaleimides with high thermal stability and low optical absorption loss in the optical communication wavelength of $1.55{\mu}m$ were investigated for application in low-loss waveguide materials. The fluorinated polymaleimides were prepared from two monomers phenylmaleimide (H-PMI) and pentafluorophenylmaleimide (F-PMI). All synthesized copolymers had high thermal stability (decomposition temperature $(T_d)=380-430^{\circ}C$). The refractive index of the copolymers could be tuned from 1.4969 to 1.5950 in the TE mode and from 1.4993 to 1.5932 for the TM mode at 632.8 nm by copolymerizing different weight ratios of H-PMI and F-PMI. The refractive index of the copolymers decreased with increasing F-PMI content. In addition, when the amount of F-PMI was increased, optical loss and absorption loss at 632.8 nm and 1550 nm, respectively, decreased.

• 한국유가공학회:학술대회논문집
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• 2005.10a
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• pp.1-9
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• 2005

The ubiquitous presence of lactoferrin (LF) receptor in human as reported by the research group of Prof, Bo Lonnerdal, Univ. California, encouraged us to search for the unknown physiological roles of LF. Under the collaboration with Prof. Etsumori Harada, Tottori Univ., and his research group, we have found two novel biological activities of LF as the control of the lipid metabolism and the effect on the central nervous system. Relating to the lipid metabolism, LF could, in animal experiments, reduce triglyceride and total cholesterol both in blood and liver. LF increased plasma HDL-C and lowered LDL-C. In the central nervous system, LF showed anti-nociceptive activity mediated by ${\mu}$-opioid receptor in the rat spinal cord. LF enhanced analgesic action of morphine synergistically via nitric oxide synthesis. LF showed opioid-mediated suppressive effect on distress induced by maternal separation in rat pups.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.463-463
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• 2013

This paper reports the synthesis and characterization of ZnO:Ga nano-structures deposited on Au/SiNx/Si(001) by radio-frequency sputtering. The effect of the temperature on the microstructure of the as-grown ZnO:Ga thin films was examined. The growth mode of ZnO:Ga nano-structures can be explained by the profile coating, i.e. the ZnO nano-structures were formed with a morphological replica of Au seeds. Initially, the ZnO:Ga nano-structures were overgrown on top of Au nano-crystals. Small ZnO:Ga nano-dots were then nucleated on hexagonal ZnO:Ga discs.

• Archives of Pharmacal Research
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• v.28 no.11
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• pp.1213-1218
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• 2005

N,N-Dialkylditihiocarbamate derivatives have been well known as broad-range fungicides. In this study, the triazole derivatives of ten new N,N-disubstituted dithiocarbamates (3a-j) were synthesized and their structures were identified by spectral and elemental analysis. Results of the antifungal activity studies showed that some of the compounds tested were active against M. canis, M. gypseum, and T rubrum at the concentration of 12.5 $\mu$g/mL when c1otrimazol was used as a standard.

• Archives of Pharmacal Research
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• v.27 no.6
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• pp.581-588
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• 2004

A series of 2, 5-dihydroxychalcones and related compounds were synthesized, and their cyto-toxicities against tumor cell lines and human umbilical venous endothelial cells (HUVEC） eval-uated. It was found that chalcones, with electron-withdrawing substituents on an A ring, exhibited significant cytotoxicities. Among the synthesized compounds, 2'-chlbro-2, 5-dihydrox-ychalcone (9） was most potent, with an $IC_{50}$ value as low as $0.31{\;}{\mu\textrm{g}}/mL$. This compound also exhibited a significant cytotoxic selectivity toward HUVEC.

• YAKHAK HOEJI
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• v.42 no.5
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• pp.540-543
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• 1998

The nitric oxide (NO) produced in large amounts by inducible nitric oxide synthase is known to be responsible for the vasodilation and hypotension observed in septic shock. We have found that 8-epi-xanthatin from Xanthium strumarium L. inhibited the production of NO in LPS-activated RAW 264.7 cells ($IC_{50}$ value was 1.5 ${\mu}$M). This activity was resulted from the suppressing of inducible nitric oxide synthase enzyme expression.

• Elastomers and Composites
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• v.27 no.4
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• pp.267-274
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• 1992

Polydimethylsiloxane(PDMS)-containing polyurethane coating materials were synthesized because PDMS-based elastomers have unique properties including an extremely low glass transition temperature, good thermal and oxidative stability, and good dielectric properties. In this experiment a vinyl copolymer which consisted of vinyl chloride, vinyl acetate, vinyl alcohol, and maleic acid was used, and Coronate L was used as a polyisocyanate. PDMS-containing polyurethane was synthesized from polydimethylsiloxane, MDI, and 1,4-butanediol. Films were casted by reaction of viny copolymer, Coronate L, and PDMS-containing polyurethane. Thickness of tile films were $150-170{\mu}m$ and the films were characterized by IR, DSC, and Instron.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.2
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• pp.102-108
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• 2001

In this paper, an active noise controller for a communication headset was designed. In a communication headset, there exist information signals such as voices from the end for the communication line as well as also, undesirable noises with are induced by external noise sources such as engine noises. Therefore, it is necessary to reduce the external noises for clear hearing of the communication signals. This problem was solved by robust H(sub)$\infty$ controller to reduce noise and a compensator for information signals The designed controller was implemented using TMS320C31 DSP Op-amp, and several experiments were performed to verify its performance. The results showed that the controller reduces the undesirable noises sufficiently, while communication signals are not reduced.