HFSS Modeling in Aqueous Biological Samples for EPR

用于 EPR 的水性生物样品中的 HFSS 建模

• 批准号: 7231696
• 负责人: JAMES S HYDE
• 金额: $ 32万
• 依托单位: MEDICAL COLLEGE OF WISCONSIN
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-06-01 至 2008-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7231696
• 关键词: Biological; Biomedical Research; Biophysics; Blood capillaries; Cells; Class; Computer software; Computer-Aided Design; Computers; Coupled; Data Quality; Device Designs; Electromagnetic Fields; Electron Spin Resonance Spectroscopy; Elements; Environment; Equation; Evaluation; Feedback; Frequencies; Funding; Goals; Image; Investigation; Laboratories; Lead; Letters; Life; Liquid substance; Medical; Metals; Methods; Modality; Modeling; Molecular Structure; Mus; Numbers; Paper; Performance; Phase; Placement; Publications; Publishing; Purpose; Relative (related person); Reporting; Research Institute; Research Personnel; Sampling; Site; Solid; Solutions; Speed; Spin Labels; Spin Trapping; Structure; Surface; Wisconsin; Work; aqueous; base; capillary; college; concept; design; design and construction; electric field; improved; in vivo; innovation; instrument; membrane model; microwave electromagnetic radiation; practical application; programs; research study; retinal rods; tissue preparation

DESCRIPTION (provided by applicant): This proposal is device design driven. The goal of the proposed work is to improve sensitivity in electron paramagnetic resonance (EPR) spectroscopy of aqueous fluid phase samples. There are two themes: (i) multifrequency enhancement from 1 to 35 GHz, and (ii) optimization for samples of limited availability (ca., 1 microliter), intermediate availability (ca., 10-20 microliters) and unlimited availability (>100 microliters). This goal will be achieved by optimization of microwave resonator design and by optimization of aqueous sample cell design. The proposal is timely because of recent advances in software for finite element modeling of electromagnetic fields, coupled with greatly improved computing speeds. Computer aided design will be used for resonators, sample cells and field modulation coils, followed by experimental evaluation. There are five Specific Aims: (1) Aqueous samples for loop gap resonators. This has not been the primary subject of any previous publication. (2) Uniform Field resonators for aqueous samples. This innovative class of resonators, introduced and developed in three recent papers from the PI's laboratory and published in the Review of Scientific Instruments, holds great promise when larger amounts of sample are available. (3) Evaluation of several types of aqueous sample cell clusters. It has been found in a recently introduced commercial product that clusters of sample cells can be bundled together and are useful in practical applications. The concept has not been the subject of any publication and a number of opportunities exist for further enhancement. (4) Re-entrant cavity resonators for aqueous samples. The design is innovative. This approach permits optimization of resonators for specific applications. One proposed here is for murine in vivo EPR imaging at L-band. (5) Field modulation numeric optimization. No previous use of finite element modeling has been reported for this purpose. EPR spectroscopy is an important modality in biomedical research. Studies of short-lived radicals detected by spin trapping, of molecular structure using site directed spin labeling, of biological or model membranes using spin probes, and of cell or tissue preparations are usually carried out in an aqueous environment. Work proposed here will improve the quality of data obtained in these experiments. An additional benefit is provided by Uniform Field resonators. Because the microwave field is uniform over the sample, all portions respond in the same way, which improves the data quality.

描述（由申请人提供）：该提案是设备设计驱动的。拟议工作的目标是提高水相样品电子顺磁共振（EPR）光谱的灵敏度。有两个主题：(i) 从 1 到 35 GHz 的多频增强，以及 (ii) 对有限可用性（约 1 微升）、中间可用性（约 10-20 微升）和无限可用性（> 100 微升）。这一目标将通过优化微波谐振器设计和优化水样样品池设计来实现。该提议是及时的，因为电磁场有限元建模软件的最新进展，加上计算速度的大幅提高。计算机辅助设计将用于谐振器、样品单元和场调制线圈，然后进行实验评估。有五个具体目标： (1) 用于环隙谐振器的水样。这并不是之前任何出版物的主要主题。 (2) 用于水样的均匀场谐振器。 PI 实验室最近在三篇论文中介绍和开发了这种创新型谐振器，并发表在《科学仪器评论》上，当有大量样品可用时，这种谐振器具有巨大的前景。 (3)几种水样细胞簇的评价。人们发现，在最近推出的商业产品中，样品池簇可以捆绑在一起，并且在实际应用中很有用。该概念尚未成为任何出版物的主题，并且存在许多进一步增强的机会。 (4) 用于水样的凹腔谐振器。设计新颖。这种方法允许针对特定应用优化谐振器。这里提出的一种方案是在 L 波段进行小鼠体内 EPR 成像。 (5)场调制数值优化。以前没有报道过为此目的使用有限元建模。 EPR 光谱是生物医学研究的重要方式。通过自旋捕获检测的短寿命自由基的研究、使用定点自旋标记的分子结构的研究、使用自旋探针的生物或模型膜的研究以及细胞或组织制剂的研究通常在水性环境中进行。这里提出的工作将提高这些实验中获得的数据的质量。均匀场谐振器还提供了一个额外的好处。由于样品上的微波场是均匀的，因此所有部分都以相同的方式响应，从而提高了数据质量。