Continuous Wave Electron Paramagnetic Resonance Imaging

连续波电子顺磁共振成像

• 批准号: 8349015
• 负责人: murali cherukuri
• 金额: $ 49.38万
• 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/8349015
• 关键词: Carbonates; Dental Enamel; Dose; Electron Spin Resonance Spectroscopy; Exposure to; Goals; Growth; Human; Hydroxide Ion; Hydroxides; Hydroxyapatites; Image; In Vitro; Ionizing radiation; Ions; Measurement; Measures; Methods; Oral cavity; Population; Property; Radiation; Sampling; Signal Transduction; Solid; Temperature; Time; Tooth structure; Triage; Whole-Body Irradiation; base; biodosimetry; dosimetry; evaporation; in vivo; inorganic phosphate; piperidine

For an EPR spectral intensity standard useful for human biophysical dosimetry, the following are the requirements: 1) A solid standard which is non-hygroscopic 2) Should have an EPR spectrum which can be measured at room temperature. 3) The spectrum should be non-overlapping with the radiation-induced signals from teeth. 4) The standard sample should be easily prepared and standardized. Several groups have tried to develop such an EPR spectral intensity standard with the above mentioned properties but did not succeed. We have developed successfully a standard which complies with the criteria described above. In brief, we grew single crystals of the diamagnetic compound, 4-hydroxy 2,2,6,6 tetramethyl piperidine by slow evaporation. During crystal growth, we doped the paramagnetic molecule, 4-hydroxy 2,2,6,6 tetramethyl piperidine-1-oxyl, which has significant structural similarity with the host molecule. We obtained crystals using several concentrations of the dopant to arrive at an EPR spectrum with intensity in the range of the radiation-induced signals in the teeth.

对于用于人类生物物理剂量测定法的EPR光谱强度标准，以下是要求：1）一个非高光谱的固体标准2）应具有可以在室温下测量的EPR光谱。 3）光谱应与牙齿辐射诱导的信号无重叠。 4）标准样品应易于制备和标准化。几个小组试图使用上述特性开发出这样的EPR光谱标准，但没有成功。我们已经成功开发了一个符合上述标准的标准。简而言之，我们通过缓慢蒸发生长了二磁化合物的单晶，4-羟基2,2,6,6四甲基哌啶。在晶体生长过程中，我们掺杂了顺磁分子，4-羟基2,2,6,6四甲基哌啶-1-氧基，该甲氧氨酸-1-氧基与宿主分子具有显着的结构相似性。我们使用几个浓度的掺杂剂获得了晶体，以在牙齿中辐射诱导的信号范围内到达EPR光谱。