Joint 3-D Reconstruction from Cryo Electron Microscopy and Solution X-ray Scattering Data

该研究的目的是开发新方法，用于联合分析冷冻电子显微镜（EM）和溶液X射线散射数据，以确定球形病毒的3D结构。在这方面的研究是及时的，因为改进的显微镜和冷冻EM技术正在增加流动的图像，而同步加速器和相关的低角度散射光束线允许测量定性上级解决方案的X射线散射数据。 联合使用这两种类型的数据是一种自然的方法，因为可以弥补优势和劣势。 例如，低温EM图像取决于未知的取向参数，而溶液X射线散射数据不依赖于未知的取向参数。 有两个主要的主题，通过工作延伸：一个新的模型的散射密度的粒子和一个统一的方式相结合的模型与所有的实验数据，以重建粒子。 该模型的目的是精确和简洁地描述粒子。 特别是，所提出的模型强制执行有限的实空间范围的粒子，允许一种以上的对称性存在与一个单独的粒子，有很少的参数，并在数学上是简单的真实的和倒易空间。

The objective of the research is the development of new methods for jointly analyzing cryoelectron microscopy (EM) and solution x-ray scattering data in order to determine the 3D structure of spherical viruses. Research in this area is timely because improved microscopes and cryo EM techniques are increasing the flow of images while synchrotrons and associated low-angle scattering beam lines allow the measurement of qualitatively superior solution x-ray scattering data. The joint use of both types of data is a natural approach because of compensating strengths and weaknesses. For instance, cryo EM images depend on unknown orientation parameters while solution x-ray scattering data does not. There are two major themes that extend through the work: a new model for the scattering density of the particle and a unified way of combining the model with all of the experimental data in order to reconstruct the particle. The purpose of the model is to precisely and concisely describe the particle. In particular, the proposed model enforces the finite real-space extent of the particle, allows more than one type of symmetry to exist with an individual particle, has few parameters, and is mathematically simple in both real and reciprocal space.