• Bulletin of the Korean Chemical Society
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• v.30 no.1
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• pp.119-123
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• 2009

Structural modifications were performed on the C-3 and C-28 positions of ursolic acid and oleanolic acid and the NO production inhibitory activities of the resulting derivatives were evaluated. The SAR revealed that the ursolic acid and oleanolic acid derivatives 3a and 4a, which possessing methoxy group at C-3 position exhibit improved NO production inhibitory activity on LPS-induced RAW247 cells while showing less cytotoxicity than the parent compounds.

• Bulletin of the Korean Chemical Society
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• v.14 no.1
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• pp.47-52
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• 1993

The vibrational relaxation rate constants of NO(v = 1-7) by $O_2\;and\;N_2$ have been calculated in the temperature range of 300-1000 K using the solution of the time-dependent Schrodinger equation. The calculated relaxation rate constants by $O_2$ increase monotonically with the vibrational energy level v, which is compatible with the experimental data, while those by $N_2$ are nearly independent of v in the range of $3.40 {\pm}1.60{\times}10_{-16} cm^3$/molecule-sec at 300 K. Those for NO(v) + $N_2$ are about 2-3 orders of magnitude smaller than those for NO(v) + $O_2$, because the latter is an exothermic processes while the former an endothermic. Relaxation processes can be interpreted by single-quantum V-V transition. The contributions of V-T/R transition and double-quantum V-V transition to the relaxation are negligible over the entire temperature range.

• Bulletin of the Korean Chemical Society
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• v.14 no.5
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• pp.625-631
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• 1993

The types of the products of the reactions between RuH(NO)(Cyttp) and alkynes are sensitive to the nature of alkynes. Terminal, nonactivated alkynes (HC${\equiv}$CR, R=Ph, hexyl and $CH_2OH)$ produce acetylide complexes and terminal (HC${\equiv}$CR, R=C(O)Me, COOEt) or internal activated ones (RC${\equiv}$ CR, R=COOMe) lead to form alkenyl complexes. On the other hand, internal nonactivated alkynes (RC${\equiv}$CR, R=Ph) do not show reactivity toward RuH(NO)(Cyttp). These products can be rationalized by the cis-concerted mechanism but the radical pathway appears to work in the reaction of propargyl chloride. From the spectroscopic data, the trigonal bipyramidal structure with a linear NO group is proposed for these products.

• Journal of the Korean Chemical Society
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• v.65 no.3
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• pp.185-196
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• 2021

For studying the reaction mechanism of the reactions related to NO in the ozone denitration reactions, the harmonic and anharmonic rate constants were calculated by the transition state (TS) theory and Yao and Lin (YL) method. According to above calculations, the reactions of NO with O₃ and NO₃ play an essential role, and the kinetic parameters considering anharmonic effect were fitted. Furthermore, the rate constants were up as temperature increasing, and the tendencies of high temperature were more gradual than the low temperature. The research will provide theoretical basis for the ozone denitration reactions.

• Proceedings of the Korean Society of Rheology Conference
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• 2003.05a
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• pp.69-72
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• 2003

No Abstract, See Full Text

• Proceedings of the Korean Society of Rheology Conference
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• 2003.05a
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• pp.111-114
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• 2003

No Abstract, See Full Text

• Proceedings of the Korean Society of Rheology Conference
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• 2002.11a
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• pp.151-154
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• 2002

No Abstract, See Full Text

• Proceedings of the Korean Society of Rheology Conference
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• 2002.11a
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• pp.73-76
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• 2002

No Abstract, See Full Text

• Proceedings of the Membrane Society of Korea Conference
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• 2002.05a
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• pp.59-61
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• 2002

No Abstract, See Full-text

• Proceedings of the Korean Society of Rheology Conference
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• 2001.09a
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• pp.156.3-156
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• 2001

(No abstract, see full-text)