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）：该建议是设备设计驱动的。建议的工作的目的是提高水流体相样样品的电子顺磁共振（EPR）光谱的敏感性。有两个主题：（i）从1到35 GHz的多频增强，以及（ii）对有限可用性的样品（约1个微晶），中间可用性（CA.，10-20微升）和无限可用性的优化（> 100 microliters）。该目标将通过优化微波谐振器设计和优化水性样品细胞设计来实现。该提案之所以及时，是因为在电磁场有限元建模软件的最新进展以及大大提高的计算速度。计算机辅助设计将用于谐振器，样品单元和现场调制线圈，然后进行实验评估。有五个特定的目的：（1）循环间隙谐振器的水样样品。这并不是任何先前出版物的主要主题。 （2）水性样品的均匀场谐振器。这种创新的谐振器类别在PI实验室的三篇论文中引入和开发，并在《科学仪器的综述》中发表，当有大量样本可用时，它具有巨大的希望。 （3）评估几种类型的水样细胞簇。在最近引入的商业产品中发现了样品簇可以捆绑在一起，并且在实际应用中很有用。这个概念不是任何出版物的主题，并且存在许多机会以进一步增强。 （4）水性样品的重入腔谐振器。设计是创新的。这种方法允许针对特定应用优化谐振器。这里提出的一种是在l波段的鼠体内EPR成像。 （5）字段调制数字优化。为此目的，尚未报告以前使用有限元建模。 EPR光谱是生物医学研究中的重要方式。通过旋转诱捕，使用位点定向自旋标记，使用自旋探针的生物或模型膜的分子结构检测到的短寿命自由基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质量。统一的现场谐振器提供了一个额外的好处。由于微波场在样本上是统一的，因此所有部分都以相同的方式做出响应，从而提高了数据质量。