Enhanced EPR Sensitivity for Biomedical Research

增强生物医学研究的 EPR 敏感性

• 批准号: 6941301
• 负责人: YURI NESMELOV
• 金额: $ 7.14万
• 依托单位: UNIVERSITY OF MINNESOTA
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-09-01 至 2006-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6941301
• 关键词: bioengineering /biomedical engineering; biomedical equipment development; biophysics; dielectric property; electron spin resonance spectroscopy; magnetic field; mathematics; method development; microwave radiation; muscle

DESCRIPTION (provided by applicant): Our long-term goal is to achieve a dramatic improvement in the sensitivity of biomedical EPR measurements. The approach is to design dielectric inserts to be used with standard commercial cavity resonators. Our hypothesis is that an insert made of appropriate materials and having appropriate dimensions can redistribute the microwave field within a cavity in a way that substantially increases the filling factor and microwave magnetic field intensity uniformly over the sample, increasing EPR sensitivity by as much as an order of magnitude. The primary emphasis of this pilot project is to design dielectric inserts that enhance sensitivity in specific applications to muscle research. Given the rapid growth of EPR in biomedical research, especially in site-directed spin labeling and high-frequency EPR, the proposed developments will have immediate impact on modem biomedical EPR measurements. This proposal is a logical extension of previous work that has demonstrated the remarkable enhancement of sensitivity of EPR measurements of spin labeled muscle fibers by ferroelectric KTaO3 insert in standard EPR cavities. Four specific aims will be addressed: (1) Develop methods for calculating the resonant frequency and microwave field distribution of an EPR cavity containing a dielectric insert, and manufacture the designed insert. (2) Modify the designs in Aim 1 for specific application important for muscle research: sample orientation parallel to the external magnetic field. (3) Perform control measurements to evaluate the physical performance of the insert. (4) Measure the improvement of signal intensity for biological samples, especially for spin-labeled muscle proteins and muscle fibers. This pilot project will emphasize the development of reliable computational methods for designing sensitivity-enhancing inserts and to demonstrate experimentally that these methods work for typical muscle research applications. This will lay the foundation for future systematic development of sensitivity enhancements for biomedical EPR research, bringing the high resolution capabilities of EPR to the analysis of complex molecular structure and dynamics in a wide range of previously inaccessible biomedical problems.

描述（由申请人提供）：我们的长期目标是实现生物医学EPR测量灵敏度的显著提高。该方法是设计与标准商业空腔谐振器一起使用的介电插入物。我们的假设是，插入适当的材料制成，并具有适当的尺寸可以重新分配的微波场在一个空腔内的方式，大大增加了填充因子和微波磁场强度均匀的样品，提高EPR灵敏度多达一个数量级。该试点项目的主要重点是设计介电插入物，以提高肌肉研究特定应用的灵敏度。鉴于EPR在生物医学研究中的快速发展，特别是在定点自旋标记和高频EPR中，所提出的发展将对现代生物医学EPR测量产生直接影响。这个建议是一个逻辑的延伸，以前的工作，已经证明了显着增强的灵敏度EPR测量的自旋标记的肌纤维铁电KTaO3插入在标准EPR腔。本论文的主要目的有四：（1）研究含介质插入物的EPR谐振腔的谐振频率和微波场分布的计算方法，并制作出所设计的插入物。(2)修改目标1中的设计，以用于对肌肉研究很重要的特定应用：样本方向平行于外部磁场。(3)进行对照测量，以评价衬垫的物理性能。(4)测量生物样品信号强度的改善，特别是自旋标记的肌肉蛋白和肌肉纤维。该试点项目将强调开发可靠的计算方法，用于设计灵敏度增强插入物，并通过实验证明这些方法适用于典型的肌肉研究应用。这将为未来系统地开发生物医学EPR研究的灵敏度增强技术奠定基础，将EPR的高分辨率能力带到复杂分子结构和动力学的分析中，以解决以前无法解决的各种生物医学问题。