• Title/Summary/Keyword: chemical susceptibility

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Opposite Effect of Spermine on the Susceptibility of Native and Denatured Calf Thymus DNA to DNase 1. (Native 및 Denatured Calf Thymus DNA의 DNase 1 에 대한 Susceptibility에 미치는 Spermine의 영향)

  • Thong-Sung Ko;Joon Huh;Chun-Bae Lee;Moo- Kyeu Park
    • Journal of the Korean Chemical Society
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    • v.27 no.6
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    • pp.429-433
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    • 1983
  • Spermine has opposite effect on the susceptibility of native and denatured calf thymus DNA toward deoxyribonuclease Ⅰ (DNase I; deoxyribonucleate 5'-oligonucleotidohydrolase; EC 3.1.4.5; from bovine pancreas). It enhances the susceptibility of the native DNA, whereas depresses that of the denatured DNA. In the absence of spermine, the reactivity of the deoxyribonuclease is apparently insensitive to the conformational difference of the native and denatured DNA.

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A Study on the Reduction of the Magnetic Susceptibility Artifact in MRI of the Cervical Spine with Chemical Shift Selective Fat Suppression (CHESS 기법을 이용한 지방소거 경추 자기공명영상에서 자화감수성 인공물을 줄이기 위한 연구)

  • Lim, Woo-Taek;Jeong, Hong-Ryang
    • Proceedings of the Korea Contents Association Conference
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    • 2014.11a
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    • pp.197-198
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    • 2014
  • CHESS(chemical shift selective saturation) 기법을 이용한 경추 자기공명영상에서 주로 나타나는 자화 감수성 인공물(susceptibility artifact)을 줄이기 위한 보조물질을 찾고자 하였다.

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In Vivo Screening for Biocontrol Agents (BCAs) against Streptomyces scabiei Causing Potato Common Scab

  • Lee, Hyang-Burm;Cho, Jong-Wun;Park, Dong-Jin;Li, Chang-Tian;Ko, Young-Hwan;Song, Jeong-Heub;Koh, Jeong-Sam;Kim, Bum-Joon;Kim, Chang-Jin
    • The Plant Pathology Journal
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    • v.20 no.2
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    • pp.110-114
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    • 2004
  • Through in vitro screening for biocontrol agents (BCAs) against Streptomyces scabiei causing potato (Solanum tuberosum) common scab, 19 streptomycete and 17 fungal isolates with antagonistic activity were selected as BCA candidates. For the selection of BCA candidates which are highly resistant to 10 kinds of antibiotics or pesticides, chemical susceptibility testing was initially performed in vitro. A remarkable degree of variation in susceptibility to antibiotics or pesticides was observed among the isolates tested. Streptomycete A020645 isolate was highly resistant to all the tested chemicals except neomycin up to 5,000 ppm. On the other hand, out of 36 antagonistic microbes subjected to in vivo pot tests using cultivar Daejima, four streptomycete isolates namely, A020645, A010321, A010564, and A020973, showed high antagonistic activity with >60% and 55% control value, respectively, and high chemical resistance to 10 kinds of chemicals. Therefore, these isolates were selected as potential BCAs for the control of potato common scab.

Cold Cracking Susceptibility in Weld Metal of High Strength-Toughness Steel (고강도 고인성강 용접금속의 저온균열 감수성에 관한 연구)

  • 이종봉;안상곤;안영호;김영우
    • Journal of Welding and Joining
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    • v.13 no.4
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    • pp.46-54
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    • 1995
  • The cold cracking susceptibility of a variety of weld metals deposited by GMAW with several kinds of commercial solid wires for high strength-toughness steel was investigated. G-BOP test and LB-TRC test were carried out to study the effects of preheat, chemical composition and hydrogen level on the weld metal cold cracking. The results obtained are as follows. 1) 10% CPT obtained by G-BOP test was the most valuable criteria for evaluating the cold cracking susceptibility of weld metals compared with percentage of cracking at room temperature and crack free temperature, and it had good correlation with the results of LB-TRC test. 2) Cold cracking susceptibility of weld metals was high in the row of MG100A, MG100C, MG100D and MG100B. Welds deposited with MG130 and MG80 showed similar icidents of cracking with MG100C and MG100B respectively, even though their strength levels were different. 3) Diffusible hydrogen level in weld metals which has good relation with hydrogen content in wire itself was the most critical factor for controlling the cold cracking susceptibility of weld metal.

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A New Method for Antimicrobial Susceptibility Testing of Vitro-cultured Bacteria by Means of Resonance Light Scattering Technique

  • Shi, Yu-Jun;Chen, Jun;Xu, Ming
    • Journal of Microbiology and Biotechnology
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    • v.18 no.1
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    • pp.118-123
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    • 2008
  • A new method for antimicrobial susceptibility testing of vitro-cultured bacteria on an ordinary fluorescence spectrometer was developed. The viable bacteria reduced 3-(4,5 dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) to produce insoluble particles that displayed intense resonance scattering light. The assay showed a linear relationship between the number of viable bacteria and the intensity of resonance scattering light. Dead bacteria were unable to reduce MTT. Methicillin-resistant Staphylococcus aureus exposed to flavonoids from Marchantia convoluta showed a flavonoids concentration-dependent inhibition of the ability to reduce MTT. In the assay, less than 12 h was required to attain susceptibility results and fewer bacteria were utilized than in traditional methods. The RLS technique could, in combination with the MTT assay, be a rapid and sensitive measuring method to determine the in vitro activity of new antimicrobials.

Inhibitory Effect of Spermine of the Susceptibility of RNA for RNase A (RNase A에 對한 RNA의 加水分解反應性에 미치는 Spermine의 抑制效果)

  • Chan Yong Lee;Heung Kyun Kim;Thong-Sung Ko
    • Journal of the Korean Chemical Society
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    • v.29 no.6
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    • pp.646-650
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    • 1985
  • RNA degradation by riboinuclease A (EC 3.1.27.5) was inhibited by spermine. As the concentration of spermine was increased, the ribonuclease activity was decreased gradually until it reached a plateau. Under the same conditions, the viscosity of the RNA increased, as the spermine concentration was increased until it reached a plateau in the same manner as the profile of the spermine-dependent ribonuclease activity. The inhibitory effect of spermine on the susceptibility of RNA to the ribonuclease could be relieved by denatured calf thymus DNA, but not by the native DNA. The data here indicate the possibility that the suppress of the RNA susceptibility for the ribonuclease by spermine is brought about by the spermine-induced intermolecular aggregation of the RNA molecules.

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MRI Artifacts

  • 최순섭
    • Investigative Magnetic Resonance Imaging
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    • v.1 no.1
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    • pp.51-57
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    • 1997
  • MRI의 artifact는 대부분 신호의 부호화 방향에 따라서 방향성을 가지는데, 이를 요약해보면, 위상부호화 방향의 artifact에는 motion artifact, flow artifact, RF noise등이 있고, 주파수 부호화 방향의 artfact는 susceptibility artfact, chemical shift artifact, central line artifact등이 있으며, 양방향 모두 생길수 있는 것은 Aliasing artifact와 Gibb's phenomenon이고, 전체적으로 영샹의 질을 떨어뜨리는 것은 susceptibility artifact, Eddy current, cross talk등이 있다. 이런 artifact는 대부분은 MRI 자체의 물리적 특성에 다소간 기인하므로, artifact가 없는 양호한 영상을 얻기 위해서는 MRI의 설치 단계부터 관심이 필요하고, MRI의 기본원리와 다양한 artifact에 대해 이해함으로써, 제거 가능한 artifact는 제거하여 양질의 영상을 만들고 판독시의 오류를 피할 수 있도록 해야할 것이다.

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