• Title/Summary/Keyword: 17B

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The Effect of Vibrationally Excited Levels on the Pressure Saturation of the Collisional Quenching of the $^3B_1\;State\;of\;SO_2

  • Bae, S. C.
    • Bulletin of the Korean Chemical Society
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    • v.17 no.1
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    • pp.56-60
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    • 1996
  • The pressure saturation effect on the phosphorescence decay rates of the $^3B_1$ State of $SO_2$ has been reinvestigated by the laser induced phosphorescence method in pure $SO_2$. We have attempted to fit the pressure dependence of the phosphorescence decay rates using the radiationless transition model by introducing different coupling constants for each vibrational level ofthe 3B1 state. The experimental decay rates can be fitted well, when the coupling constants for the (0,0,0), (0,1,0) and (0,2,0) levels of the $^3B_1$ state are $7.2\;{\times}\;10^{-4}$, $2.2\;{\times}\;10^{-3}$ and $5.9\;{\times}\;10^{-3}\;cm^{-1}$, respectively.

Analysis and Expression of Cloning of rpoB Gene of Drug-Resistant Mycobacterium tuberculosis (약제내성 Mycobacterium tuberculosis의 rpoB 유전자 분석과 클로닝 발현)

  • Choi, Eun Kyeong;Kweon, Tae-Dong;Bai, Sun-Joon;Cho, Hae Sun;Hong, Seong-Karp
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.4
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    • pp.1005-1009
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    • 2013
  • Using DNA sequencing method, we analyzed mutations of rpoB (RNA polymerase beta subunit) rifampin-resistant Mycobaterium tuberculosis strains which were identified by conventional test at Masan National Hospital and The Korean Institute of Tuberculosis. Though it has been reported different mutations of rpoB region of rifampin-resistant M. tuberculosis strains in the south of Korea, it is not confirmed whether these mutations of rpoB region actually express rifampin resistance through experiment. We confirmed experimentally these mutations of rpoB region of M. tuberculosis strains induced rifampin-resistance through ampified rpoB by polymerase chain reaction (PCR) and cloning of mutant rpoB into rifampin sensitive-M. tuberculosis strain.

First record of Bathygobius hongkongensis (Perciformes: Gobiidae) from Jeju Island, Korea

  • Kwun, Hyuck Joon
    • Fisheries and Aquatic Sciences
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    • v.23 no.7
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    • pp.17.1-17.4
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    • 2020
  • Six specimens of Bathygobius hongkongensis were collected for the first time from the eastern coast of Jeju Island, Korea, in September-November 2017. This species is characterized by a pectoral fin with free rays and the division of the first dorsalmost pectoral free ray into three branches; a lower jaw with a mental frenum; and an anterior nostril with a tiny flap. Bathygobius hongkongensis is similar to B. fuscus but differs in having more dorsalmost free pectoral fin rays. The new Korean name proposed for B. hongkongensis is "Nam-bang-mu-nui-mang-duk."

Selective Reduction of Carbonyl Compounds with B-Alkoxydiisopinocampheylborane

  • 차진순;권오운;김종미
    • Bulletin of the Korean Chemical Society
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    • v.17 no.8
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    • pp.725-729
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    • 1996
  • Reaction of carbonyl compounds with B-alkoxydiisopinocampheylborane (Ipc2BOR, R=H, Et, i-Pr, t-Bu) was investigated in detail in order to establish their usefulness as selective reducing agents. The reagents were extremely mild and reduced only aldehydes effectively under mild conditions. The reagents also reduced α,β-unsaturated aldehydes to the corresponding allylic alcohols without any detectable 1,4-reduction. Furthermore, aldehydes can be reduced in the presence of epoxides and acid chlorides. Consequently, the selective reduction of aldehyde groups in the presence of keto and all other functional groups has been realized with these reagents.

Analysis of Rotationally Cooled Vibronic Emission Spectra ($1^2A_2→1^2B_2$) of m-Xylyl Radical

  • 최익순;이상국
    • Bulletin of the Korean Chemical Society
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    • v.17 no.8
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    • pp.749-753
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    • 1996
  • The rotationally cooled but electronically excited m-xylyl radical has been generated in a jet from the gas mixture of precursor m-xylene and buffer gas He by a technique of corona excited supersonic expansion. The visible vibronic emission spectra in the transition of 12A2→12B2 of m-xylyl radical in the gas phase have been recorded using a Fourier transform spectrometer. The spectra have been analyzed for the assignments of the vibrational frequencies in the electronic ground state with combination of the torsional frequencies reported previously.

Synthesis and Reaction of Novel Tricyclic Dynemicin A Models with Methyl Group

  • 류훈한;홍용표
    • Bulletin of the Korean Chemical Society
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    • v.17 no.9
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    • pp.831-835
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    • 1996
  • New dynemicin A mimics with methyl group 2a and 2b were synthesized, and acid-induced hydrolyzed to see an electronic effect of substituent for epoxide opening. The model 2a with methyl group at C3 position was more rapidly transformed to diol 16a than 2b with methyl group at C2. This result suggests that any substituent at C3 position plays more important role than any substituent at C2 position in the dynemicin A mimic activation.

Synthesis of 3-[1-(t-Butyldimethylsilyloxy)ethyl]-4-carboxymethyl-2-azetidinone Derivatives

  • 서민효;이윤영;구양모
    • Bulletin of the Korean Chemical Society
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    • v.17 no.4
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    • pp.314-321
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    • 1996
  • Isoxazolidine derivatives 7 and 8 were synthesized from N-benzyl-C-(2-benzyloxyethyl)nitrones by 1,3-dipolar cycloaddition with ethyl crotonate. The isoxazolidine derivatives were converted to β-amino acid esters 9a and 9b by reduction with zinc in acetic acid. The β-amino acid esters were reacted with methylmagnesium bromide to give the 2-azetidinones (13a, 13b). The benzyl group of 2-azetidinones were removed by Birch reduction. The products were oxidized with PDC to give 3-[1-(t-butyldimethylsilyloxy)ethyl]-4-carboxymethyl-2-azetidinone derivatives (2a, 2c).

Determination of the minimal sequence of bovine lactoferricin responsible for apoptosis induction

  • Yoo, Yung-Choon;Lee, Kyung-Bok;Lee, Hoi-Young
    • Proceedings of the PSK Conference
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    • 2003.10b
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    • pp.134.2-135
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    • 2003
  • We examined the minimal amino acid sequence of bovine lactoferricin (Lfcin-B), a cationic peptide corresponding to residues 17-41 near the N-terminus of bovine lactoferrin, to induce apoptosis in THP-l human monocytic leukemic cells using synthetic peptides. A synthetic peptide (Lfc-17/29, amino acid sequence; FKCRRWQWRMKKL) which is consist of 13 amino acids near the N-terminus of Lfcin-B induced cell death in THP-1 cells in a dose-dependent manner, showing apparent apoptotic changes such as hypodiploid forms of genomic DNA and apoptotic DNA fragmentation. (omitted)

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