• Title/Summary/Keyword: Park Chung-Hee

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The Mechanism of Contraction Response to EFS in Cat Esophageal Circular Muscle

  • Park, Joon-Hong;Lee, Tai-Sang;Park, Sun-Young;Cho, Young-Rae;Park, Hee-Jung;Sohn, Uy-Dong
    • Proceedings of the PSK Conference
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    • 2003.10b
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    • pp.75.1-75.1
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    • 2003
  • Low-frequency electrical field stimulation of transmural nerves of cat esophageal circular smooth muscle produces an “off contraction”, which occurs after electirical field stimulation (EFS) of transmural nerves is stopped. We previously examined signal transduction pathways mediating ACh-induced contraction of circular smooth muscle of esophagus. The extracellular Ca$\^$2+/ is needed for the contraction, results in the activation PKC. EFS-induced contraction was abolished by the pretreatments of tetrodotoxin(1 ${\mu}$M) and atropine (1 ${\mu}$M). (omitted)

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Whitening Activity of Phenylpropanoid Compounds

  • Yoon, Mi-Yun;Park, Young-Mi;Lee, Jin-Hee;Kim, Youn-Joung;Kim, Chang-Jong;Sim, Sang-Soo
    • Proceedings of the PSK Conference
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    • 2003.10b
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    • pp.123.3-124
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    • 2003
  • To investigate the relationship between structure and biological activity of phenylpropanoids, we measured effects of phenylpropanoids on anti-oxidant and whitening activity. In DPPH radical scavenging activity, caffeic acid analogues had anti-oxidant activity in a dose-dependent manner. Although phenylpropanoids did not inhibit purified tyrosinase activity, they significantly inhibited tyrosinase activity and melanin production in MSH-stimulated B16 melanoma cells. (omitted)

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40kV Solid State Pulsed Power Supply for Environmental Applications (40kV 친환경 응용을 위한 반도체 기반 펄스 전원장치)

  • Song, Seung-Ho;Cho, Hyun-Bin;Park, Su-Mi;Lee, Seung-Hee;Jin, Hee-Sung;Ryoo, Hong-Je
    • Proceedings of the KIPE Conference
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    • 2018.07a
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    • pp.45-47
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    • 2018
  • This paper describes the 40kV solid state pulsed power supply for environmental applications. The output specifications of the pulsed power supply are 40kV, 300A, 3kHz, and average output power of 13kW. In order to generate a high voltage, a series stacking cell structure is used which is charged in parallel and discharged in series. Due to this structure, there is no dynamic voltage balancing problem as well as static voltage balancing problem for switches used in high voltage pulse power supplies. To verify this pulse power supply design, PSpice modeling was performed. Finally, experimental results with non-inductive resistive load and gas treatment reactor proved the reliability of the solid state pulsed power supply.

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Characteristics of lateral bud development, necrosis and genesis of flower primordium in 'Kyoho' grapevines

  • Park, Jun Young;Jung, Myung Hee;Kim, Bo Min;Park, Yo Sup;Kim, Jun Hyeok;Park, Hee-Seung
    • Korean Journal of Agricultural Science
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    • v.47 no.4
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    • pp.987-993
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    • 2020
  • This study investigated the effective harvest of 'Kyoho' grapevines by examining their characteristics including bud development, necrosis types and flower primordium formation. The size of the axillary bud did not show any difference in the 5th node or more, but it was smaller because it was closer to the base in the 4th node or less. In the 1st node, the rates of main bud necrosis (MBN), accessory bud necrosis (ABN), and whole bud necrosis (WBN) were high, and the rate of flower primordium formation was low, but there was no significant difference in the other nodes. Therefore, it was expected that using other nodes than the 1st node would be advantageous to secure production. Because the growth progresses after sprouting, the main bud necrosis rate increases, showing a very low flower primordium formation rate in March of the following year. Therefore, a method is needed to increase the storage nutrients in the winter and the rate of flower primordium formation after March. This study found that the thickness of the shoots should be less than 8.5 mm between the 3rd and 4th nodes, and the length should be less than 60 cm for nodes up to the 10th node.