SINGLET OXYGEN IN BIOLOGICAL SYSTEMS

单线态氧分子的性质及其在 光动力作用将继续是这一研究的主要焦点 集团在未来五年。实验研究将广泛 分为两类：一类是关于基本的物理， 氧气如何与电子激发态相互作用的化学方面 另一个集中在生物学方面，特别是， 光动力学机制第一类是两个具体目标。 简而言之，这些都集中在演示和表征动态 光敏剂-氧形成的激基复合物的性质 交互.这将涉及扩散相互作用， 分子-氧化合物状态的激发。其他三个目标涉及 研究细胞系统和其中的光过程。这些研究 将包括研究分子三重态的反应性 在培养的细胞中，试图建立单线态之间的关系， 氧气生产和生物效应，并继续努力， 了解光动力照射对细胞的早期影响， 体内平衡大多数物理化学工作将涉及激光闪光 光解研究。计划进行几项仪器开发 为细胞的工作，包括调查的可行性， 开发基于干涉仪的发光装置， 灵敏度和雇用光集成外壳，以提高 吸收和发射测量。

The nature and properties of singlet molecular oxygen and its role in photodynamic action will continue to be a major focus of this research group in the next five years. The experimental study will be broadly divided into two categories: one is concerned with the basic physico- chemical aspects of how oxygen interacts with electronically excited systems; the other centered on biological aspects, in particular, photodynamic mechanisms. Two specific aims constitute the first category. Briefly, these are focused on demonstrating and characterizing the dynamic properties of exciplex states formed by photosensitizer-oxygen interactions. This will involve both diffusive interactions, and excitation of molecule-oxygen compound states. Three other aims concern research on cellular systems and on photoprocesses therein. These studies will include investigations of the reactivity of molecular triplet states in cultured cells, an attempt to develop a relationship between singlet oxygen production and biological effect, and to continue our efforts to understand the early effects of photodynamic irradiation on cellular homeostasis. Most of the physico-chemical work will involve laser flash photolytic investigations. Several instrumental developments are planned for the cellular work, including an investigation into the feasibility of developing an interferometer-based luminescence device for enhanced sensitivity and the employment of light-integrating enclosures to enhance absorption and emission measurements.