The structure of content: phase contrast in a microprobe

描述（由申请人提供）：细胞的许多关键功能取决于金属的催化特性，但如果金属以异常高的浓度存在（或不正确地调节），许多这些相同的金属可能具有极高的毒性，或导致衰弱性疾病。铜和锌是抗氧化蛋白Cu/Zn超氧化物歧化酶的组分，其已被暗示在细胞老化中，并且在突变形式中已与神经退行性疾病如肌萎缩性侧索硬化症（ALS，或Lou Gehrig病）相关联。顺铂是一种众所周知的癌症治疗药物，但其对细胞中特定区域的亲和力尚不完全清楚。硬X射线微探针擅长于检测和定量生物样品中的痕量金属浓度，但目前它们不能对超微结构进行成像以将金属置于正确的细胞环境中，或确定样品质量以提供关于痕量金属浓度的真正定量信息。我们希望在硬X射线微探针中实现定量相衬成像来解决这个问题。我们将开发一个优化的分段检测器的微分相衬成像，将纳入常规使用的波带板为基础的微探针在先进的光子源在阿贡国家实验室，首屈一指的硬X射线同步光源在美国，我们将开发方法和软件的定量相衬分析使用新的检测器获得的数据。虽然我们已经证明了一些例子，定量相衬图像在软X射线显微镜，我们现在希望开发软件，使这种分析方法常规提供给用户的APS微探针。我们的目标是让用户在他们的生物医学研究专家（但不是在X射线光学和分析方法），以用户友好的方式利用这种能力与免费提供的软件。然后，我们希望证明该系统的能力，以量化试样质量和观察亚100纳米结构的细胞同时映射微量元素分布。第三代储存环的X射线微探针代表了数百万美元的投资。真正量化元素浓度而不仅仅是元素含量的能力，以及将其与细胞超微结构相关联的能力，是非常需要的，正如使用X射线微探针进行NIH支持研究的独立研究人员的支持信所表明的那样。

DESCRIPTION (provided by applicant): Numerous key functions of cells hinge upon the catalytic properties of metals, yet if metals are present in abnormally high concentrations (or incorrectly regulated) many of these same metals can be extremely toxic, or lead to debilitating diseases. Copper and zinc are components of the anti-oxidant protein Cu/Zn superoxide dismutase, which has been implied in cellular aging and in mutant forms has been linked to neurodegenerative diseases such as amytrophic lateral sclerosis (ALS, or Lou Gehrig's disease). Cisplatin is a well-known drug for cancer therapy but its affinity for specific regions in a cell is imperfectly understood. Hard X-ray microprobes excel at detecting and quantifying trace metal concentrations in biological samples, but at present they cannot image ultrastructure to place the metals in their correct cellular context, or determine the specimen mass so as to deliver truly quantitative information on trace metal concentration. We wish to implement quantitative phase contrast imaging in a hard x-ray microprobe to address this problem. We will develop an optimized segmented detector for differential phase contrast imaging that will be incorporated into routine use in a zone plate based microprobe at the Advanced Photon Source at Argonne National Laboratory, the premier hard x-ray synchroton light source in the U.S. We will develop methodology and software for quantitative phase contrast analysis using data obtained with the new detector. While we have demonstrated a few examples of quantitative phase contrast images in soft x-ray microscopy, we now wish to develop software to make this analysis approach routinely available to users of the APS microprobe. Our goal is to allow users expert in their biomedical studies (but not in x-ray optics and analysis methods) to exploit this capability with freely-available software in a user friendly fashion. We then wish to demonstrate the ability of the system to quantify specimen mass and observe sub-100 nm structure in cells simultaneously with mapping trace elemental distributions. X-ray microprobes at third generation storage rings represent a multimillion dollar investment. The ability to truly quantify element concentrations instead of just elemental content, and to correlate this to cellular ultrastructure, is keenly desired as indicated by letters of support from independent investigators who use X-ray microprobes for their NIH-supported studies.