SMALL-ANGLE MICRO DIFFRACTION OF BIOLOGICAL MATERIALS

这个子项目是许多利用资源的研究子项目之一 由NIH/NCRR资助的中心拨款提供。子项目的主要支持 而子项目的主要调查员可能是由其他来源提供的， 包括其它NIH来源。 列出的子项目总成本可能 代表子项目使用的中心基础设施的估计数量， 而不是由NCRR赠款提供给子项目或子项目工作人员的直接资金。 过去一年的工作表明，BioCAT K-B镜系统是生物材料中广角纤维衍射的有效和通用系统的基础。然而，对于肌肉系统，我们通常对低角度和广角信息都感兴趣。 类似地，对于胶原系统（例如骨），看到低角度信息以及广角信息将是有用的。这些研究的目的是观察仪器的最小d间距是否可以向下推，以适合从肌肉收集低角度信息。尝试了12和8 keV的能量，集中在样品和检测器上。结果表明，在8 keV，很容易分辨60 nm的一级，无论是在检测器或在样品聚焦，可以从肌肉获得非常好的结果。我们还发现，通过聚焦样品（约10微米焦斑），可以获得比传统仪器更上级的骨切片衍射图案。随着一些进一步的发展，它似乎应该能够在67 nm处分辨胶原蛋白的第一级，这对于扫描微衍射应用是非常期望的。 这些结果还表明，相同的装置可以用于使用微流体混合器的时间分辨SAXS和WAXS研究。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Work over the last year has demonstrated that the BioCAT K-B mirror system be the basis of an effective and versatile system for medium and wide angle fiber diffraction from biological materials. Frequently with muscle systems, however, we are interested both low and wide angle information. Similarly, with collagenous systems (such as bone) it would be useful to see the low-angle information as well as the wide angle. The purpose of these studies was to see if the minimum d-spacing of the instrument could be pushed down to be suitable to collect low-angle information from muscle. Both 12 and 8 keV energies were tried, focused at both the sample and at the detector. The results indicated that very good results could be obtained from muscle at 8 keV, easily resolving 60 nm first order, focussed at either the detector or at the sample. We also discovered that far superior diffraction patterns from bone sections could be obtained by focusing at the sample (~10 micron focal spot) than can be obtained with conventional instrumentation. It appears with some further development it should be able to resolve the first order of collagen at 67 nm, which would be highly desirable for scanning micro-diffraction applications. These results also indicated that the same apparatus could be useful for time resolved SAXS and WAXS studies using micro-fluidic mixers.