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测量敏感性的显着提高。方法是设计介电插入物，以与标准的商业空腔谐振器一起使用。我们的假设是，由适当的材料制成并具有适当尺寸的插入物可以以大大增加样品均匀增加的填充因子和微波磁场强度的方式将微波场重新分布，从而将EPR敏感性提高到数量级。该试点项目的主要重点是设计介电插入物，以增强对肌肉研究的特定应用的敏感性。鉴于EPR在生物医学研究中的快速增长，尤其是在现场定向的自旋标记和高频EPR中，拟议的开发将对现代生物医学EPR测量产生立即影响。该提案是先前工作的逻辑扩展，它证明了通过铁电KTAO3插入物在标准EPR腔中通过铁电KTAO3插入物在旋转标记的肌肉纤维的EPR测量值的显着提高。将解决四个具体目标：（1）开发用于计算包含介电插入物的EPR腔的谐振频率和微波场分布的方法，并制造设计的插入物。 （2）修改AIM 1中针对肌肉研究重要的特定应用的设计：平行于外部磁场的样品取向。 （3）执行控制测量以评估插入物的身体性能。 （4）测量生物样品的信号强度的改善，尤其是针对自旋标记的肌肉蛋白和肌肉纤维的改善。该试点项目将强调开发可靠的计算方法，以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。这将为生物医学EPR研究的敏感性增强的未来系统发展奠定基础，这将EPR的高分辨率能力带入了复杂分子结构和动力学的分析，这是在以前无法访问的生物医学问题的广泛范围内。