Dose-response curves for Fricke-infused agarose gels as obtained by nuclear magnetic resonance.
Dose-response curves for Fricke-infused agarose gels as obtained by nuclear magnetic resonance.
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DOI：
10.1088/0031-9155/35/12/002
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发表时间：
1990-12
影响因子：
3.5
通讯作者：
R J Schulz;A F deGuzman;D B Nguyen;J C Gore
中科院分区：
文献类型：
--
作者：
R J Schulz;A F deGuzman;D B Nguyen;J C Gore
本文研究了用Sparke剂量计溶液制备的琼脂糖凝胶的辐射响应特性。的响应机制是由三价铁离子引起的质子的NMR纵向弛豫速率的增加。有人指出：（i）氧饱和度确保一致和最大灵敏度;（ii）1.0-2.0%范围内的琼脂糖浓度对灵敏度没有影响;（iii）对于含有0.5 mM Fe 2+离子的凝胶，初始G值为150 Fe 3 +/100 eV;（iv）增加NMR频率仅引起灵敏度的适度增加;（v）凝胶剂量计在4.7-24.2戈伊min-1范围内与剂量率无关;（vi）灵敏度与pH有关，在pH 7时为零;（vii）新鲜制备的凝胶比24小时以上的凝胶稍敏感;和（ix）三价铁离子在含有0.0125 M H2SO 4的1.0%琼脂糖凝胶中的扩散系数为1.83 × 10（-2）cm 2 h-1，这将需要考虑剂量分布的NMR成像。
The radiation-response characteristics of agarose gels prepared with Fricke dosemeter solution have been studied. The response mechanism is an increase in the NMR longitudinal relaxation rate of protons caused by ferric ions. It has been observed that: (i) oxygen saturation assures consistent and maximum sensitivity; (ii) agarose concentrations in the range 1.0-2.0% have no effect upon sensitivity; (iii) the initial G value is 150 Fe3+/100 eV for gels containing 0.5 mM Fe2+ ions; (iv) increasing NMR frequencies only causes a moderate increase in sensitivity; (v) the gel dosemeters are dose rate independent in the range 4.7-24.2 Gy min-1; (vi) sensitivity is pH dependent, being zero at pH 7; (vii) freshly prepared gels are slightly more sensitive than those more than 24 h old; and (ix) the diffusion coefficient for ferric ions in a 1.0% agarose gel containing 0.0125 M H2SO4 is 1.83 x 10(-2) cm2 h-1, and this will require consideration for the NMR imaging of dose distributions.