3D TOMOGRAPHY MODELS IN ELECTRON MICROSCOPY OF CRYSTALS

描述(改编自申请)：本研究方案涉及 开发两个高度可并行化的全三维 在电子领域具有广泛适用性的重构模型 晶体的显微镜(EM)，基于3D圆环的几何形状。其中一个 提出的成像模型是为了研究原子结构 由一种以上的原子通过透射电子显微镜形成的晶体。 本工作是对以前开发的成功模型的改进 特别适用于具有单一原子的晶体的层析成像。这个 其他层析成像模型允许对结晶生物分子进行成像 以及分子聚集体和复合体，如RNA、DNA、蛋白质和 核糖体，它可以结晶。这项工作是基本的，因为它可以 允许提取以前无法获得的结构和形态 来自生物分子的电子显微镜的信息。由于一个强大的 信噪比，这种重建技术提供了额外的 优点是需要比传统方法更低的辐射剂量，这 可以通过限制结构退化来保证样品的完整性 复杂的有机物种。 将对重建的质量和速度进行比较研究 对从当前感兴趣的结晶样品获得的数据执行， 考虑到其他现有成像模型的性能。AS 作为拟议研究的副产品，调查人员预计将产生 用于EM设施的软件包，适用于这两种型号。长期的 这项提议的目标是在 波多黎各大学，融入多学科环境，旨在 帮助我们的研究人员在生物医学领域的需求。

Description (Adapted from Application): This research proposal deals with the development of two highly parallelizable, fully three-dimensional reconstruction models with extensive applicability in the field of electron microscopy (EM) of crystals, based on the geometry of the 3D Torus. One of the imaging models proposed is aimed at the study of the atomic structure of crystals formed by atoms of more than one kind, by means of transmission EM. The present work is an enhancement to the previous successful model developed specifically for tomography of crystals endowed with a single kind of atom. The other tomography model allows the imaging of crystallized biological molecules and molecular aggregates and complexes, such as RNA, DNA, proteins and ribosomes, which can be crystallized. This work is fundamental in that it could permit the extraction of previously unobtainable structural and morphological information from the electron microscopy of biomolecules. Due to a robust signal-to-noise ratio, this reconstruction technique offers an additional advantage by requiring lower radiation doses than conventional methods, which could guarantee sample integrity by limiting the structural degradation in complex organic species. A comparative study of the quality and speed of the reconstruction will be performed on data obtained from crystallized specimens of current interest, taking into consideration the performance of other existing imaging models. As a byproduct of the proposed research, the investigators expect to produce software packages to be used in EM facilities, for both models. The long-term objective of this proposal is to create an image processing unit at the University of Puerto Rico, integrated to a multidisciplinary environment, aimed at assisting the needs of our researchers in the biomedical area.