| Project/Area Number |
62470004
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
物理化学一般
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| Research Institution | Tokyo University of Fisheries |
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Principal Investigator |
WATANABE Tokuko Professor of Chemistry, Tokyo University of Fisheries., 水産学部, 教授 (40092382)
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| Co-Investigator(Kenkyū-buntansha) |
MURASE Norio Assoc. Prof. of Chemistry, Tokyo Denki University., 理工学部, 助教授 (40120125)
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| Project Period (FY) |
1987 – 1988
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| Project Status |
Completed (Fiscal Year 1988)
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| Budget Amount *help |
¥5,900,000 (Direct Cost: ¥5,900,000)
Fiscal Year 1988: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1987: ¥5,000,000 (Direct Cost: ¥5,000,000)
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| Keywords | NMR / ESR / spin probe / relaxation time / water / gel / freezing-thawing mechanism / 架橋高分子ゲル / 組織水 / ゲル / T_2 / 凍結解凍機構 / NMR / 生体内の水 / 緩和時間 / 凍結解凍の機構 |
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| Research Abstract |
Water in biological tissues and foods plays an important role both biologically and physicochemically. Relaxation times of water proton, T1 and T2, reflect different environments of water and different interactions of water with the surrounding tissues or biological marcomolecules. In the present research such factors determining T1 abd T2 as the size of compartmentalized water, water content or flexibility of the surrounding matrix were investigated by using sephadex gels with various pore sizesand water contents as the model compound. Multi-exponential analysing process was developed in the analysis of T2 relaxation time and applied to tissue characterization of the myocardium of dog.
Dynamic behavior of water molecules also relates to characteristic of compartmentalized water. The second purpose of the research is to make the thermal motion of water clear by spin probe-ESR method. Rotational correlation times of the probe reflects the rate of confliction between the probe and surrounding water molecules.
Results are summalized as follows; 1) Relaxation times depend strongly on pore size of gel and water content. A critical size in motional behavior at which a confliction of relaxation times appeared was the size of G25 gel. The result was published in Magn.Reson.Med. 9, 1-7(1989). 2) Relaxation process was caused by two interactions, one is intra- and inter- molecular dipolar interaction and the other is proton exchange between bound water and hydroxyl proton of gel matrix. The latter mechanism was dominant in the case of G25 gel and the former one was dominant for water in gels with larger pore than G25. 3) Rotational correlation time and activation enerby of rotational diffusion of spin probe in G25 gel are quite different from those in other gels. It is interesting that the specific motional property observed in ESR and NMR occurs just under the condition in which the abnormal thermal behavior was observed.
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