优化电子束能量,以利用MeV-STEM进行纳米分辨率的厚冷生物样本的现场成像
Xi Yang1, Liguo Wang2, Victor Smaluk1
1National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, NY 11973, USA.
Nanomaterials (Basel, Switzerland)
|May 10, 2024
概括
研究人员优化了电子能量的纳米尺度成像厚厚的生物样本. 一个分析模型预测了保持纳米分辨率的最佳能量,用于高达10微米厚的样品.
科学领域:
- 电子显微镜的电子显微镜
- 生物物理学的生物物理.
- 材料科学 是一种材料科学.
背景情况:
- 厚厚的生物样本的现场成像需要优化电子束能量以获得纳米级分辨率.
- 现有的方法面临着光束扩大和剂量限制在较厚的标本中的挑战.
研究的目的:
- 为厚厚的生物样本开发MeV-STEM中优化电子能量的分析模型.
- 为了预测和最大限度地减少横梁大小在电子束穿越过程中扩大.
- 分析剂量有限分辨率对成像结果的影响.
主要方法:
- 基于弹性和不弹性特征角度的分析模型的实施.
- 使用蒙特卡洛模拟进行模型的基准测试.
- 对剂量有限的分辨率效应的分析.
- 在MeV-STEM列中使用双阶段镜头系统.
- 与超低发射电子源的集成.
主要成果:
- 该模型准确地预测了横梁尺寸的扩大,作为电子能量的函数.
- 确定了最佳的电子束能量 (<10μm样品低于10MeV,>10μm样品高于10MeV或更高).
- 波束大小可以在样本中减少到1nm,使用MeV-STEM列和优化能量.
- 通过10微米生物样本的最大电子束大小保持在10纳米以下.
结论:
- 优化电子能量对于实现纳米分辨率至关重要 在厚厚的生物样本的现场成像中.
- 开发的分析模型和MeV-STEM系统使得高分辨率成像的标本高达10微米厚.
- 这项工作代表了纳米尺度成像在生物和材料科学中的重大进步.
更多相关视频
相关概念视频
Cryo-electron Microscopy
3.3K
Conventional electron microscopy (EM) involves dehydration, fixation, and staining of biological samples, which distorts the native state of biological molecules and results in several artifacts. Also, the high-energy electron beam damages the sample and makes it difficult to obtain high-resolution images. These issues can be addressed using cryo-EM, which uses frozen samples and gentler electron beams. The technique was developed by Jacques Dubochet, Joachim Frank, and Richard Henderson, for...
3.3K
Transmission Electron Microscopy
5.5K
In 1931, physicist Ernst Ruska—building on the idea that magnetic fields can direct an electron beam just as lenses can direct a beam of light in an optical microscope—developed the first prototype of the electron microscope. This development led to the development of the field of electron microscopy. In the transmission electron microscope (TEM), electrons are produced by a hot tungsten element and accelerated by a potential difference in an electron gun, which gives them up to 400...
5.5K
Preparation of Samples for Electron Microscopy
5.4K
To be visualized by an electron microscope, either transmission or scanning, biological samples need to be fixed (stabilized) so the electron beam does not destroy them and dried thoroughly (desiccated/dehydrated) so the vacuum does not affect them. Fixation needs to be done as quickly as possible because the sample properties will start changing as soon as it is removed from its natural environment. For example, in a tissue sample, the oxygen levels begin decreasing, causing an altered...
5.4K
Electron Microscope Tomography and Single-particle Reconstruction
2.4K
Transmission electron microscopy (TEM) can be used to determine the 3D structure of biological samples with the help of techniques such as electron microscope tomography and single-particle reconstruction. While single-particle reconstruction can examine macromolecules and macromolecular complexes in vitro conditions only, tomography permits the study of cell components or small cells in vivo.
Electron Tomography
Electron tomography can be performed either in TEM or STEM (scanning transmission...
Electron Tomography
Electron tomography can be performed either in TEM or STEM (scanning transmission...
2.4K


