Application of time-resolved femtosecond laser spectroscopy to biological, medical and environmental studies

实时观察分子系统中发生的反应在化学、生物学、材料科学、环境科学和医学等各个领域都非常重要。对反应的监测可以识别刺激反应的分子途径；一旦确定了途径，就可以对反应进行修改和控制。时间分辨超快激光光谱学是一种非常强大的实时观察分子反应的技术。本提案描述了一种将高灵敏度时间分辨飞秒激光光谱技术应用于各种分子体系的原始方案。目标是获得这些系统中超快电子转移反应的实时观察结果，并揭示它们对环境过程，特别是大气臭氧消耗，以及癌症治疗等生物医学应用的重要性。提出了新的实验来解决含卤素分子的超快电子转移反应，作为臭氧消耗分子和作为癌症治疗的无线电/光敏药物。预计这些飞秒激光光谱研究将揭示超快电子转移反应在生物和环境系统中的重要意义，包括水在放射生物学中的新作用，halopy嘧啶作为致敏药物在癌症放射治疗中的作用的分子机制，以及了解臭氧洞形成的机制。

Real-time observations of reactions occurring in molecular systems are of great importance in diverse fields from chemistry, biology, materials science, environmental science to medicine.  The monitoring of reactions can lead to the identification of molecular pathways stimulating the reactions; once the pathways are identified, the reactions can then be modified and controlled.  Time-resolved ultrafast laser spectroscopy is a tremendously powerful technique for real-time observations of molecular reactions. This proposal describes an original program to apply high-sensitivity time-resolved femtosecond laser spectroscopic technique to various molecular systems.  The objectives are to obtain real-time observations of ultrafast electron transfer reactions in these systems and to reveal their importance for environmental processes, particularly atmospheric ozone depletion, and for biomedical applications such as cancer treatments.  New experiments are proposed to address ultrafast electron transfer reactions of halogen-containing molecules as ozone depleting molecules and as radio-/photo-sensitizing drugs for cancer treatments.  It is anticipated that these femtosecond laser spectroscopic studies will reveal the significance of ultrafast electron transfer reactions in biological and environmental systems, ranging from novel effects of water in radiobiology, molecular mechanisms of action of halopyrimidines as sensitizing drugs in radiotherapy of cancer, to understanding the mechanism for the formation of the ozone hole.