New directions for x-ray spectrometry from portable to synchrotron science

该提案旨在开发和使用新的X射线光谱法检测人体组织中的微量元素。科学的规模范围从便携式，桌面，X射线仪器到大型同步加速器设施。该提案的重点是X射线荧光和X射线吸收，用于研究包括锌，砷和硒在内的一系列元素。与其他小组的合作将允许使用更多和不同的分析方法。正在考虑的样品将包括组织模拟材料和真实的组织，如手指甲和脚趾甲。该提案的三个相互关联的目标是：（1）开发一种创新的便携式单能X射线荧光技术;（2）将便携式X射线荧光与其他新兴科学方法进行比较;（3）利用加拿大光源的同步加速器辐射调查组织中微量元素之间的关系。** 微型X射线管和X射线光学器件的最新发展首次使单能便携式X射线荧光技术适用于组织研究。一个单能量的光束，调整到一个有利的能量，将大大优于以前的方法，使用一系列的能量。这在试图检测组织中的微量元素时很重要。还将研究新的数据分析方法，以评估人造和真实的指甲屑中的元素。结果将进行比较和对比，从其他方法，包括激光烧蚀电感耦合等离子体质谱，激光诱导击穿光谱，和显微X射线荧光。同步辐射时间将用于调查指甲屑中元素的分布和化学形式。将寻找证据，以证明指甲内存在砷和硒的特定结合物。** 使用电离辐射探测组织是这项研究计划的核心，福尔斯属于医学物理和辐射物理领域。一个快速，精确，便携式系统可靠地评估指甲屑中的锌水平的演示将是一个重大的发展，可以促进世界范围内的补锌工作。同样，有有趣的证据表明，砷暴露的影响可能会被硒的摄入抵消。因此，评估砷和硒水平的方法很重要，更好地了解砷和硒之间的结合机制至关重要。为了考虑这些问题，拟议的研究包括从基础科学到辐射物理学实际应用的各个方面。********

This proposal seeks to develop and use new x-ray spectrometry approaches for the detection of trace elements in human tissue. The scale of the science ranges from portable, desktop, x-ray instruments to large-scale synchrotron facilities. The proposal focuses on x-ray fluorescence and x-ray absorption for the study of a series of elements including zinc, arsenic, and selenium. Collaboration with other groups will allow the use of additional and different methods of analysis. Samples under consideration will include tissue-simulating materials and real tissue such as fingernails and toenails. Three inter-related objectives of the proposal are: (1) development of an innovative and portable mono-energetic x-ray fluorescence technique; (2) comparison of portable x-ray fluorescence with other emerging scientific methods; and (3) investigation of the relationships between trace elements in tissue using synchrotron radiation at the Canadian Light Source. ******Recent developments in miniature x-ray tubes and x-ray optics have for the first time made mono-energetic portable x-ray fluorescence feasible for tissue studies. A mono-energetic beam, tuned to a favorable energy, will vastly outperform previous methods which use a range of energies. This is important when trying to detect trace elements in tissue. New approaches to data analysis will also be studied for the assessment of elements in artificial and real nail clippings. Results will be compared and contrasted with those from other methods including laser ablation inductively coupled plasma mass spectrometry, laser induced breakdown spectroscopy, and micro x-ray fluorescence. Synchrotron beam time will be used to investigate the distribution and chemical form of elements in nail clippings. Evidence will be sought for the presence of a specific conjugate of arsenic and selenium within nail. ******The use of ionizing radiation for probing tissue is central to this program of research, which falls within the fields of medical physics and radiation physics. The demonstration of a fast, precise, and portable system for reliably assessing levels of zinc in nail clippings would be a significant development which could facilitate worldwide zinc supplementation efforts. Likewise, there has been intriguing evidence that the effects of arsenic exposure may be counteracted by intake of selenium. A means of assessing both arsenic and selenium levels is therefore important, and a better understanding of the mechanism of binding between arsenic and selenium is critical. To consider such issues, the proposed research incorporates aspects ranging from basic science to practical applications of radiation physics. ********