SINGLET OXYGEN IN BIOLOGICAL SYSTEMS

单重态分子氧的性质和性质及其在生物化学中的作用 光动力作用将继续是这项研究的主要重点 集团将在未来五年内。这项实验研究将广泛地 分为两类：一类是关于基础物理的-- 氧如何与电子激发相互作用的化学方面 系统；另一个集中在生物学方面，特别是， 光动力机制。两个具体目标构成了第一类。 简而言之，这些都集中在演示和描述动态 光敏剂-氧形成激发态的性质 互动。这将涉及扩散的相互作用，以及 分子-氧化合物态的激发。其他三个目标关注 研究蜂窝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，试图发展单胞体之间的关系 氧气的产生和生物效应，并继续努力 了解光动力照射对细胞的早期影响 动态平衡。大部分的物理化学工作将涉及激光闪光灯 光解研究。计划进行几项工具性开发 用于蜂窝工作，包括调查 基于干涉仪的增强型发光器件的研制 敏感度和使用光集成外壳来增强 吸收和排放测量。

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.