Electron Transport in Tissue-like Material

类组织材料中的电子传输

• 批准号: 7088227
• 负责人: LARRY H TOBUREN
• 金额: $ 21.42万
• 依托单位: EAST CAROLINA UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-12-01 至 2009-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7088227
• 关键词: DNA damage; bioenergetics; biophysics; biotransformation; cytotoxicity; electrical measurement; electron transport; electronic spectra; high energy particle; hydrogen ions; ionizing radiation; mass spectrometry; radiobiology; radiological health

DESCRIPTION (provided by applicant): This proposal is a revised competitive renewal of a three year grant initiated in July, 2002. The proposed study of electron emission from thin foils is designed to provide data to test computational models developed to describe the initial spatial pattern of energy deposition by ionizing radiation in biologic material. These initial damage patterns affect subsequent chemistry and biochemistry that influence crucial cellular pathways leading to biological repair, genomic instability, apoptosis, and/or finally cancer induction. Much of our knowledge of the initial patterns of radiation damage is obtained from event-by-event Monte Carlo track simulation models that often contain uncertainties in their cross section database. The current work, and the proposed extension, provides data on which we can test track simulation models at the level of the physics of electron transport, i.e., prior to modification and averaging by chemical reactions. During the initial grant period data have been obtained for electron transport in water, a major constituent of tissue; SF6, a unique molecule with well defined structure in the low-energy electron transport spectra; and preliminary data have been obtained for several molecules that aid in assessment of effects of surfaces bonding and molecular structure on electron spectra, e.g., data have been derived from solid (frozen) CO2, C2H6, C3H6, C2F2H2, and Xenon. Continuing study of hydrocarbons is underway and target technology is being developed to extend this work to larger bio-molecules and tissue. The cryogenic target provides a unique capability to study bio-molecules and tissue as a function of temperature and thereby as a function of water content. A major goal of the continued work is to better understand the role of water in the transport of electrons in bio- molecules and tissue. We feel this expanded study will provide unique insight into the role of tissue constituents on electron transport, and provide data that can provide sensitive tests of evolving models of electron transport following energy deposition by ionizing radiation. This work will contribute to increased accuracy in the assessment of local dose distributions delivered to cells, cellular components, and critical biomolecules. The results will enhance our effort to establish clinically relevant radiation treatment with a better understanding of potential damage to healthy tissue.

描述（由申请人提供）：该提案是对 2002 年 7 月发起的三年资助的修订竞争性更新。拟议的薄箔电子发射研究旨在提供数据来测试为描述初始空间模式而开发的计算模型生物材料中电离辐射的能量沉积。这些最初的损伤模式影响随后的化学和生物化学，从而影响导致生物修复、基因组不稳定、细胞凋亡和/或最终诱导癌症的关键细胞途径。我们对辐射损伤初始模式的大部分了解都是从逐个事件的蒙特卡罗轨迹模拟模型中获得的，这些模型的横截面数据库中通常包含不确定性。当前的工作和拟议的扩展提供了数据，我们可以在电子传输的物理层面上测试轨道模拟模型，即在通过化学反应进行修改和平均之前。在最初的资助期间，已经获得了水中电子传输的数据，水中电子传输是组织的主要成分； SF6，一种在低能电子传输光谱中具有明确结构的独特分子；已经获得了几种分子的初步数据，有助于评估表面键合和分子结构对电子光谱的影响，例如，数据来自固体（冷冻）CO2、C2H6、C3H6、C2F2H2 和氙。对碳氢化合物的持续研究正在进行中，并且正在开发目标技术以将这项工作扩展到更大的生物分子和组织。低温靶提供了一种独特的能力来研究生物分子和组织作为温度的函数，从而作为水含量的函数。持续工作的一个主要目标是更好地了解水在生物分子和组织中电子传输中的作用。我们认为这项扩展研究将为组织成分对电子传输的作用提供独特的见解，并提供数据，可以对电离辐射能量沉积后电子传输演化模型进行敏感测试。这项工作将有助于提高细胞、细胞成分和关键生物分子局部剂量分布评估的准确性。这些结果将加强我们建立临床相关放射治疗的努力，更好地了解对健康组织的潜在损害。