Collaborative Research: Examining the Binding of Radionuclides with Marine Biopolymers, A Comparative Study on TH, PA, BE, PO and PB Isotopes

“这项奖励是根据2009年美国复苏和再投资法案（公法111-5）资助的。”虽然天然放射性同位素，如Th（IV）、Pa（IV， V）、Po（IV， II, -II）和Be（II）是长期用于海洋研究的重要代用物，但放射性核素与海洋有机物之间的分子相互作用和结合关系尚不清楚。经过多年的研究，海洋中的金属离子主要受海洋微生物排泄的生物聚合物和其他有机分子的控制，生物聚合物在用作海洋示踪剂的天然放射性核素的生物地球化学循环中起着重要作用。为了识别和表征这些生物聚合物载体化合物与示踪剂研究中使用的放射性核素之间的关系，德克萨斯农工大学和南密西西比大学的科学家将对钍（Th）、镤（Pa）、钋（Po）、铅（Pb）和铍（Be）的放射性同位素进行比较研究。该实验室和实地实验将确定作为有效海洋结合配体的放射性同位素载体，并阐明各种天然放射性同位素的海洋化学示踪剂应用的基础。更广泛的影响：这项研究的结果将增强我们对海洋中自然放射性核素和碳循环的生物地球化学控制的基本理解。这项研究还将改进对GEOTRACES程序中收集的数据的解释。该项目还涉及学生培训和国际合作。

"This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5)."Although natural radioisotopes, such as Th(IV), Pa(IV, V), Po(IV, II, -II), and Be(II), are important proxies that have long been used in oceanographic investigations, the molecular interactions and binding relationships between radionuclides and marine organic matter remain unclear. Through years of research, it has become evident that metal ions in the ocean are mostly controlled by biopolymers and other organic molecules excreted by marine micro-organisms, and that biopolymers play a significant role in the biogeochemical cycles of the natural radionuclides that are used as oceanographic tracers. To identify and characterize the relationships between these biopolymeric carrier compounds and the radionuclides used in tracer research, scientists from Texas A&M University and the University of Southern Mississippi will conduct a comparative study on radioisotopes of thorium (Th), protactinium (Pa), polonium (Po), lead (Pb), and beryllium (Be). This laboratory and field experiment will identify the radioisotope carriers that are effective marine binding ligands and clarify the basics of oceanographic chemical tracer applications of various natural radioisotopes. Broader Impacts: The results from this research will enhance our fundamental understanding of the biogeochemical controls on natural radionuclide and carbon cycling, in the oceans. This research will also refine the interpretation of data collected in the GEOTRACES program. The project also involves the training of students and international collaborations.