Elemental calcium plays an important role in human physiology. In order to study the relationship between Ca-intake, Ca-chemical formulation, and Ca-absorptivity, a balance experiment using a ^(41)Ca tracer technique ...Elemental calcium plays an important role in human physiology. In order to study the relationship between Ca-intake, Ca-chemical formulation, and Ca-absorptivity, a balance experiment using a ^(41)Ca tracer technique in SD rats was conducted to measure the endogenous fecal calcium and true absorption of calcium. Apparent absorption of calcium was measured as a control to the endogenous calcium labeling experiment. These results show that by using ^(41)Ca labeled endogenous calcium in vivo, researchers could obtain the true calcium absorption data without extrinsic labeling. Therefore, the method was not affected by the chemical structure or type of calcium supplement and might be used in evaluating the absorptivity of marketed calcium supplements.展开更多
使用放射性同位素在生命科学领域有着悠久的历史,14C和41Ca作为两种长寿命放射性核素已被广泛应用于生物体代谢的示踪研究。加速器质谱(accelerator mass spectrometry,AMS)测量技术作为一种能够准确测量低丰度、长寿命同位素的核分析技...使用放射性同位素在生命科学领域有着悠久的历史,14C和41Ca作为两种长寿命放射性核素已被广泛应用于生物体代谢的示踪研究。加速器质谱(accelerator mass spectrometry,AMS)测量技术作为一种能够准确测量低丰度、长寿命同位素的核分析技术,克服了传统质谱存在的分子本底和同量异位素本底干扰的限制。该方法不受检测物质的复合结构及基体效应的影响,非常适合14C与41Ca生物样品的测量。介绍了AMS测量技术的基本原理和优势及目前通过该技术测量14C与41Ca在生物代谢研究中的应用情况。重点介绍了中国原子能科学研究院AMS小组目前正在从事的14C与41Ca在生物代谢领域的测量工作。展开更多
The recipients of the 1997 CAS Awards for Young Scientists had their names publicized recently. They had been checked and recommended by their work units and subject to re-examination and approval by the Awards’ jury...The recipients of the 1997 CAS Awards for Young Scientists had their names publicized recently. They had been checked and recommended by their work units and subject to re-examination and approval by the Awards’ jury. As a result, a total of 41 prodigies received this special honor for展开更多
为满足41Ca生物示踪样品测量的需要,在北京HI-13串列加速器质谱(Accelerator Mass Spec- trometry,AMS)系统上建立了以CaF2为靶样的41Ca AMS分析方法.生物样品和41Ca标准样品经过化学分离和纯化,制备成CaF2作为靶物质,AMS测量41Ca时,离...为满足41Ca生物示踪样品测量的需要,在北京HI-13串列加速器质谱(Accelerator Mass Spec- trometry,AMS)系统上建立了以CaF2为靶样的41Ca AMS分析方法.生物样品和41Ca标准样品经过化学分离和纯化,制备成CaF2作为靶物质,AMS测量41Ca时,离子源引出CaF3-负离子,膜剥离后的电荷态选择为7+态,加速器端电压选定为8.5MV,用充有140mbarP10气体的多阳极电离室探测41Ca.结果显示探测器可实现对41Ca与同量异位素干扰41K的分辨,粒子谱中41K的计数率很低,对41Ca不形成干扰.对制备的4个标准样品(41Ca/40Ca在1.785×10-8-1.750×10-10范围)的测量结果显示41Ca/40Ca绝对测量值与标称值之间的线性关系良好(r2=0.997),经41Ca/40Ca为1.785×10-8的标准样品归一化后,S2,S4两个标样的测量值与标称值吻合较好,但标样S3的测量值与标称值有较大偏离.估计生物样品的41Ca/40Ca本底值低于8.2×10-13.展开更多
基金supported by the National Nature Science Foundation of China(No.11375272)
文摘Elemental calcium plays an important role in human physiology. In order to study the relationship between Ca-intake, Ca-chemical formulation, and Ca-absorptivity, a balance experiment using a ^(41)Ca tracer technique in SD rats was conducted to measure the endogenous fecal calcium and true absorption of calcium. Apparent absorption of calcium was measured as a control to the endogenous calcium labeling experiment. These results show that by using ^(41)Ca labeled endogenous calcium in vivo, researchers could obtain the true calcium absorption data without extrinsic labeling. Therefore, the method was not affected by the chemical structure or type of calcium supplement and might be used in evaluating the absorptivity of marketed calcium supplements.
文摘使用放射性同位素在生命科学领域有着悠久的历史,14C和41Ca作为两种长寿命放射性核素已被广泛应用于生物体代谢的示踪研究。加速器质谱(accelerator mass spectrometry,AMS)测量技术作为一种能够准确测量低丰度、长寿命同位素的核分析技术,克服了传统质谱存在的分子本底和同量异位素本底干扰的限制。该方法不受检测物质的复合结构及基体效应的影响,非常适合14C与41Ca生物样品的测量。介绍了AMS测量技术的基本原理和优势及目前通过该技术测量14C与41Ca在生物代谢研究中的应用情况。重点介绍了中国原子能科学研究院AMS小组目前正在从事的14C与41Ca在生物代谢领域的测量工作。
文摘The recipients of the 1997 CAS Awards for Young Scientists had their names publicized recently. They had been checked and recommended by their work units and subject to re-examination and approval by the Awards’ jury. As a result, a total of 41 prodigies received this special honor for
文摘为满足41Ca生物示踪样品测量的需要,在北京HI-13串列加速器质谱(Accelerator Mass Spec- trometry,AMS)系统上建立了以CaF2为靶样的41Ca AMS分析方法.生物样品和41Ca标准样品经过化学分离和纯化,制备成CaF2作为靶物质,AMS测量41Ca时,离子源引出CaF3-负离子,膜剥离后的电荷态选择为7+态,加速器端电压选定为8.5MV,用充有140mbarP10气体的多阳极电离室探测41Ca.结果显示探测器可实现对41Ca与同量异位素干扰41K的分辨,粒子谱中41K的计数率很低,对41Ca不形成干扰.对制备的4个标准样品(41Ca/40Ca在1.785×10-8-1.750×10-10范围)的测量结果显示41Ca/40Ca绝对测量值与标称值之间的线性关系良好(r2=0.997),经41Ca/40Ca为1.785×10-8的标准样品归一化后,S2,S4两个标样的测量值与标称值吻合较好,但标样S3的测量值与标称值有较大偏离.估计生物样品的41Ca/40Ca本底值低于8.2×10-13.
