Electron Transport in Tissue-Like Material

类组织材料中的电子传输

• 批准号: 6535872
• 负责人: LARRY H TOBUREN
• 金额: $ 19.21万
• 依托单位: EAST CAROLINA UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-07-01 至 2005-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6535872
• 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 study will provide experimental data for understanding electron transport in the heterogeneous cellular environment and enable stringent tests of charged-particle track-structure simulation at the level of the underlying physics of energy transport, i.e., prior to assumptions of the nature of chemical and bio-chemical pathways leading to biological alterations. Much of our knowledge of the biological effectiveness of radiation to create DNA damage and cellular mutagenesis is based on Monte Carlo based simulations of the initial patterns of energy deposition. Because of a lack of detailed information on cross sections for interactions in the condensed phase, Monte Carlo simulations often use interaction cross sections derived from gas phase data, or from largely untested theoretical techniques. Uncertainties in these data might have detrimental effects on the accuracy by which patterns of energy deposition can be determined at microscopic dimensions such as are involved in the production of multiply damaged sites, damage clusters, in DNA. Since these codes provide the data upon which radiobiologic interpretations of dose-response relationships are based, they are a direct link to understanding the biological effects of radiation exposures, whether these exposures are environmental, diagnostic, or therapeutic. This work focuses on measurement of the spectra of electrons produced in thin films of condensed phase material by the transit of fast protons. Spectra, differential in ejected electron energy and emission angle, are measured following electron transport and their emergence from the material surface. The transport media of interest include water, hydrocarbons, oligonucleotides, oligopeptides and DNA in thin films and/or frozen as ices. The spectra will be compared to predictions of Monte Carlo codes that incorporate gas and/or condensed phase interaction cross sections to test the sensitivity and reliability of the codes to the details of the input data. This, the first direct test of the fundamental physics of electron transport in track simulation codes commonly used in radiobiology, will provide guidance for the application of these codes in radiobiology and strengthen confidence in our evolving understanding of the energy transport pathways leading to cellular damage and mutagenesis by ionizing radiation.

描述（由申请人提供）：本研究将提供实验数据，以了解在异质性细胞环境中的电子传输，并在能量传输的基础物理学水平上，即在假设化学和生物化学途径的假设之前，对带电的粒子轨道轨道结构模拟进行了严格的测试。我们对辐射产生DNA损伤和细胞诱变的生物学有效性的许多了解都是基于基于蒙特卡洛的能量沉积模式的模拟。由于缺乏有关凝结阶段相互作用的横截面的详细信息，因此蒙特卡洛模拟通常使用从气相数据或在很大程度上未经测试的理论技术中得出的相互作用横截面。这些数据中的不确定性可能会对能量沉积模式在微观维度上确定的准确性产生不利影响，例如与DNA中乘积损坏的位点，损伤簇的生产有关。由于这些代码提供了剂量反应关系的放射生物学解释基于的数据，因此它们是了解辐射暴露的生物学效应的直接联系，无论这些暴露是环境，诊断还是治疗性。 这项工作的重点是测量通过快速质子的转运在冷凝相材料中产生的电子光谱。在电子传输及其从材料表面出现后测量了弹出电子能量和发射角的光谱。感兴趣的传输介质包括薄膜中的水，碳氢化合物，寡核苷酸，寡肽和DNA和/或冷冻作为冰。将将光谱与蒙特卡洛代码的预测进行比较，这些蒙特卡罗代码结合了气体和/或凝结相互作用横截面，以测试代码对输入数据细节的灵敏度和可靠性。这是对放射性生物学通常使用的轨道模拟代码中电子传输基本物理学的首次直接测试，它将为这些代码在放射生物学中应用这些代码提供指导，并增强我们对通过电离辐射导致细胞损伤和诱变的能量传输途径不断发展的理解的信心。