Continuous Wave Electron Paramagnetic Resonance Imaging

连续波电子顺磁共振成像

• 批准号: 7338601
• 负责人: murali cherukuri
• 金额: --
• 依托单位: DIVISION OF BASIC SCIENCES - NCI
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/7338601
• 关键词: Continuous; Wave; Electron; Paramagnetic; Resonance

Project 3: Continuous Wave Electron Paramagnetic Resonance Imaging.Instrumentation: The current spectrometer is an analog spectrometer which is operational at 300 and 750 MHz. Most components are analog devices which have their own contributions to noise and artifacts which will compromise the signal:noise ratio. DSP (digital signal processing) technology is increasingly being used in modern telecommunication systems as well as consumer electronics and cost of these modules has become small. The noise associated with several analog components in RF electronics can be avoided by relying on DSP strategies where possible. We plan to develop a general EPR spectrometer platform based on DSP strategy to confer versatility in operation with a nominal operating frequency of 750 MHz during the initial phase. Subsequent to this, we plan to incorporate capabilities in the spectrometer to operate at 300 MHz as well. In the proposed system, detection schemes such as direct detection with rapid scan as well as phase-sensitive detection using ac modulation of the dc magnetic field can be integrated. This system will use digital synthesizers to generate all RF and control signals and a 'Software Radio' based receiver. Three major components of this system: RF source, receiver and magnetic field controller are under various stages of development. Applications: The strength of this technique in detecting phenotypic changes of genetically modified animals is demonstrated by the studies using wild type and Thrombospondin-1 null mice with surgical wounds in the skin flap. TSP-1 is a putative antagonist of perfusion and tissue survival and can limit survival of soft tissue following surgery. This hypothesis was tested using oxygen sensing paramagnetic solid probes at proximal and distal sites to the wound on the skin flap and the tissue pO2 was monitored using EPR spectroscopy. EPR studies, histological analysis and western blot analysis on wild type and TSP-1 null mice showed that endogenous TSP-1 was inhibitory to the vascular smooth muscle relaxation by nitric oxide.Other studies examined the effect of core body temperature in mice on the pO2 values in muscle and mammary tissue using chronically implanted oxygen sensing solid paramagnetic particles whose oxygen dependent spectral line widths were monitored over a period of 4 weeks. The studies showed that the femoral muscles function at higher pO2 than the mammary fat pad and also indicated the importance of maintaining core body temperature for valid monitoring of physiology.Experimental Subjects:Neither human subjects nor human tissues.

项目三：连续波电子顺磁共振成像。仪器：当前的光谱仪是一种模拟光谱仪，可在300和750 MHz下运行。大多数元件都是模拟器件，它们对噪声和伪影有自己的贡献，这将损害信噪比。DSP（数字信号处理）技术越来越多地用于现代电信系统以及消费电子产品中，并且这些模块的成本已经变得很小。在可能的情况下，可以通过依赖DSP策略来避免与RF电子器件中的多个模拟元件相关的噪声。我们计划开发一个通用的EPR谱仪平台的基础上，DSP的战略，赋予在操作的通用性与标称工作频率为750 MHz的初始阶段。在此之后，我们计划将光谱仪的功能也纳入300 MHz。在所提出的系统中，检测方案，如直接检测快速扫描以及相敏检测使用交流调制的直流磁场可以集成。该系统将使用数字合成器来生成所有RF和控制信号以及基于“软件无线电”的接收器。该系统的三个主要组成部分：射频源、接收器和磁场控制器处于不同的开发阶段。应用领域：该技术在检测转基因动物的表型变化中的优势通过使用皮瓣中具有手术伤口的野生型和血小板反应蛋白-1缺失小鼠的研究来证明。TSP-1是灌注和组织存活的假定拮抗剂，并且可以限制手术后软组织的存活。在皮瓣伤口的近端和远端部位使用氧传感顺磁性固体探针测试该假设，并使用EPR光谱监测组织pO 2。EPR研究，对野生型和TSP-1基因敲除小鼠的组织学分析和蛋白质印迹分析表明，内源性TSP-1基因敲除小鼠的组织学分析和蛋白质印迹分析显示，其他研究使用长期植入的氧敏感固体顺磁颗粒检测小鼠核心体温对肌肉和乳腺组织中pO 2值的影响，其氧依赖性光谱线宽度在一段时间内被监测4周。这些研究表明，在较高的pO 2比乳房脂肪垫的股骨肌肉的功能，也表明了维持核心体温的重要性，有效的监测physiology.Experimental科目：既不是人类受试者也不是人体组织。