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

本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，台式，x射线仪器到大型同步加速器设备。该提案侧重于x射线荧光和x射线吸收，以研究一系列元素，包括锌、砷和硒。与其他小组的合作将允许使用额外的和不同的分析方法。正在考虑的样品将包括组织模拟材料和真实组织，如指甲和脚趾甲。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量x射线荧光技术；(2)便携式x射线荧光与其他新兴科学方法的比较；(3)利用加拿大光源同步辐射研究组织中微量元素之间的关系。******微型x射线管和x射线光学的最新发展首次使单能便携式x射线荧光技术在组织研究中成为可能。单能量光束，调谐到一个有利的能量，将大大优于以前使用一系列能量的方法。当试图检测组织中的微量元素时，这一点很重要。还将研究新的数据分析方法，以评估人工和真实指甲剪中的元素。结果将与激光烧蚀、电感耦合等离子体质谱、激光诱导击穿光谱和微x射线荧光等其他方法的结果进行比较和对比。同步加速器束时间将用于研究指甲屑中元素的分布和化学形式。证据将寻求砷和硒在指甲内的特定共轭物的存在。******利用电离辐射探测组织是本研究项目的核心，属于医学物理学和辐射物理学领域。证明一种快速、精确、便携的系统可以可靠地评估指甲屑中的锌含量，这将是一项重大的发展，可以促进世界范围内的锌补充工作。同样，有有趣的证据表明，砷暴露的影响可以通过摄入硒来抵消。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的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. ********