Elemental analysis in medical physics and astro-geology

拟议的研究计划的中心主题是辐射物理学在医学物理和天体地质学中的元素分析应用。 该计划包括三个主要举措：1）测量火星土壤样本中的束缚水在美国宇航局2004/2006年使命期间，火星探测漫游者上携带的α粒子X射线光谱仪（APXS）提供了大量火星岩石和土壤样本的元素分析。 有人认为，这些样本中含有大量水体蒸发后留下的盐，2009/2010年将部署先进的APXS，以进一步调查这一假设。 本研究项目将根据APXS光谱中观察到的散射特征，研究间接检测火星样品中轻元素的灵敏度。2）用X射线衍射测量银职业接触银可能发生在许多环境中。 此外，银化合物的医药用途重新出现，在替代医学中得到推广。这种暴露可能导致不良的生物效应，如银中毒，一种永久性的皮肤变色。这项工作将调查的应用程序的非侵入性的体内技术检测银在个人的皮肤谁是在发展中国家的风险银，目的是提供一种手段干预之前，这种不可逆的皮肤条件的发病。3）测量氮与γ射线共振吸收的能力，测量氮是一个直接的手段，评估蛋白质状态在许多营养失调。本研究的目的是调查一种替代方法，目前的方法，这是有问题的。 这种新的测量技术有可能大大改善目前方法的均匀性和剂量，并将促进许多医疗和健康相关领域的临床研究，例如营养科学，儿科学，老年学，运动学和康复科学。

The central theme of the proposed research program is the application of radiation physics to elemental analysis in medical physics and astro-geology.  The program consists of three major initiatives:1) Measuring Bound Water in Martian Soil SamplesThe alpha-particle x-ray spectrometers (APXS) carried on the Mars Exploration Rovers during NASA's 2004/2006 mission have provided elemental analysis of a large number of Martian rock and soil samples.  There are some suggestions that these samples contain salts left behind after the evaporation of large bodies of water, and an advanced version of APXS will be deployed in 2009/2010 to further investigate this hypothesis.  This research project will investigate the sensitivity of indirect detection of light elements in Martian samples based on the observed scatter features present in the APXS spectra.2)Measuring Silver with X-ray FluorescenceOccupational exposure to silver can occur in many settings.  Furthermore, there has been a re-emergence of the medicinal use of silver compounds, promoted in alternative medicine. Such exposure can lead to adverse biological effects such as argyria, a permanent skin discoloration. This work will investigate the application of a non-invasive in vivo technique to detect silver in the skin of individuals who are at risk of developing argyria, with the aim of providing a means of intervening before the onset of this irreversible skin condition.3) Measuring Nitrogen with Gamma-ray Resonance AbsorptionThe ability to measure nitrogen is a direct means of assessing protein status in many nutritional disorders. The goal of this research is to investigate an alternative approach to the current method, which is problematic.  This new measurement technique has the potential to improve substantially the uniformity and dose of the current method, and would facilitate clinical studies in a number of medical and health-related fields, e.g. nutritional sciences, pediatrics, gerontology, kinesiology and rehabilitation sciences.