| Project/Area Number |
13450086
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Thermal engineering
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| Research Institution | Kyushu Institute of Technology |
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Principal Investigator |
TSURUTA Takaharu Kyushu Institute Of Technology, Department of Mechanical Engineering, Professor, 工学部, 教授 (30172068)
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| Co-Investigator(Kenkyū-buntansha) |
KOSHINO Hidekazu Kyushu Institute Of Technology, Department of Mechanical Engineering, Educational Staff, 工学部, 教務職員 (60145167)
TANIGAWA Takaharu Kyushu Institute Of Technology, Department of Mechanical Engineering, Research Associate, 工学部, 助手 (80197524)
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| Project Period (FY) |
2001 – 2003
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| Project Status |
Completed (Fiscal Year 2003)
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| Budget Amount *help |
¥14,100,000 (Direct Cost: ¥14,100,000)
Fiscal Year 2003: ¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 2002: ¥5,800,000 (Direct Cost: ¥5,800,000)
Fiscal Year 2001: ¥6,600,000 (Direct Cost: ¥6,600,000)
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| Keywords | Cryopreservation / Intracellular Ice Formation / Microwave / Water Molecule / Molecular Dynamics / Hydrogen Bond / Propagation of Ice Formation / 凍結伝播機 / スラリー / アモルファス |
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| Research Abstract |
Effects of microwave irradiation on intracellular ice formation of tissue cells have been examined precisely by using onion epidermis. Microscopic observations of the freezing processes have been carried out with use of a constant cooling stage and a directional solidification stage. In order to quantify the relation between the freezing temperature of cells and the microwave irradiation energy, the optical fiber thermometers and the microwave intensity meter were installed in the experimental systems. The microwave at 2.45GHz was irradiated from a spot antenna and the power was changed up to 50 mW/cm^2.
The constant cooling rate tests show that an increase of the irradiation power of microwave decreases the freezing temperature in a range between 10mW/cm^2 and 15 mW/cm^2 while at 25 mW/cm^2 the freezing temperature increase again. This indicates that the optimum irradiation power exists for a suppression of intracellular ice formation by microwave irradiation. The experiments using the directional solidification stage also show the same results on the average freeing temperature under the microwave irradiation conditions. In addition, special interesting findings we have in the test. The directional solidification stage enables us to simulate the propagation of cell freezing which occurs in the tissue cells. It is found that the microwave irradiation reduces the probability of the propagation-type freezing induced by neighboring-cell freezing. Therefore, we can restrain from, the intercellular ice formation occurring at relatively small supercooling which gives a mechanical damage to the cell.
We have also done the molecular dynamics simulation by using a SPC/E potential as water potential model. The simulations indicate us the, effectiveness of microwave irradiation for the cryopreservation and it is found that there may exist an effective wave-length rather than 2.45GHz.
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