相关实验视频
Updated: Jun 24, 2025

08:47
A 3D Cartographic Description of the Cell by Cryo Soft X-ray Tomography
Published on: March 15, 2021
3.9K
基于断层图像重建的X射线晶体学光线追踪分析吸收校正.
Yishun Lu1, Ramona Duman2, James Beilsten-Edmands2
1Oxford e-Research Centre, Department of Engineering Science, University of Oxford, 7 Keble Road, Oxford OX1 3QG, United Kingdom.
概括
一种新的分析吸收校正方法改善了宏分子结晶学 (MX) 数据处理,特别是在长波长. 这种在AnACor软件中实现的方法,与标准实证模型相比,提供了更好的结果.
科学领域:
- 晶体学 晶体学是指结晶学.
- 生物物理学的生物物理.
- 材料科学 材料科学 材料科学
背景情况:
- 大分子结晶学 (MX) 数据处理涉及强度集成和随后的校正.
- 在MX中,吸收效应通常较小,但在长波长时变得显著.
- 目前在MX软件中的实证吸收校正模型与长波长强吸收的高保真模型作斗争,特别是在低数据复数的情况下.
研究的目的:
- 为MX数据开发和评估一种新的分析吸收校正策略.
- 将新策略的性能与标准的经验方法进行比较,特别是在长波长.
- 评估更好的吸收校正对实验分阶段和数据质量的影响.
主要方法:
- 开发了一个分析吸收校正策略,在一个名为AnACor.的新软件中实现.
- 该策略使用从X射线断层扫描中获得的体积样本模型和射线追踪方法来确定个体反射路径长度.
- 分析吸收校正的性能与球体波校正和使用两种膜蛋白样本 (OmpK36 GD和化物脱酶) 在长波长 (3.54 Å和4.13 Å) 的联合方法进行了比较.
主要成果:
- 与标准的球体波调整相比,分析吸收校正策略 (AnACor) 显示出更高的性能.
- 对于3.54 Å的数据来说,改进是适度的,但对于4.13 Å的更长波长的数据来说是显著的.
- 新方法减少了成功在更长波长的实验阶段化所需的数据量.
结论:
- 基于X射线断层扫描的分析吸收校正为处理MX中强烈的吸收效应提供了更可靠的方法,特别是在长波长时.
- 该AnACor软件提供了比实证方法的显著进步,以提高数据质量,并逐步成功挑战晶体学实验.
- 这种方法对于推进膜蛋白和其他需要长波长数据收集的宏分子的结构研究至关重要.
相关概念视频
X-ray Crystallography
23.9K
The size of the unit cell and the arrangement of atoms in a crystal may be determined from measurements of the diffraction of X-rays by the crystal, termed X-ray crystallography.
Diffraction
Diffraction is the change in the direction of travel experienced by an electromagnetic wave when it encounters a physical barrier whose dimensions are comparable to those of the wavelength of the light. X-rays are electromagnetic radiation with wavelengths about as long as the distance between neighboring...
Diffraction
Diffraction is the change in the direction of travel experienced by an electromagnetic wave when it encounters a physical barrier whose dimensions are comparable to those of the wavelength of the light. X-rays are electromagnetic radiation with wavelengths about as long as the distance between neighboring...
23.9K
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
X-ray Diffraction of Biological Samples
3.8K
X-ray diffraction or XRD is an analytical tool that utilizes X-rays to study ordered structures such as crystalline organic and inorganic samples, polycrystalline materials, proteins, carbohydrates, and drugs.
According to Bragg's law, when X-rays strike the sample positioned on a stage, the rays are scattered by the electron clouds around the sample atoms. The X-ray diffraction or scattering is caused by constructive interference of the X-ray waves that reflect off the internal...
According to Bragg's law, when X-rays strike the sample positioned on a stage, the rays are scattered by the electron clouds around the sample atoms. The X-ray diffraction or scattering is caused by constructive interference of the X-ray waves that reflect off the internal...
3.8K
Attenuated Total Reflectance (ATR) Infrared Spectroscopy: Overview
350
Attenuated total reflectance (ATR) infrared spectroscopy is a powerful analytical technique used to study the composition of materials. It is widely employed in chemistry, materials science, forensic science, and other fields where sample characterization is required. ATR has several advantages over traditional transmission IR spectroscopy, including the requirement of little to no sample preparation and the ability to analyze a wide range of samples.
The ATR process begins by directing a beam...
The ATR process begins by directing a beam...
350
Computed Tomography
4.5K
Tomography refers to imaging by sections. Computed tomography (CT) is a non-invasive imaging technique that uses computers to analyze several cross-sectional X-rays to reveal minute details about structures in the body.
The technique was invented in the 1970s and is based on the principle that as X-rays pass through the body, they are absorbed or reflected at different levels. In the technique, a patient lies on a motorized platform while a computerized axial tomography (CAT) scanner rotates...
The technique was invented in the 1970s and is based on the principle that as X-rays pass through the body, they are absorbed or reflected at different levels. In the technique, a patient lies on a motorized platform while a computerized axial tomography (CAT) scanner rotates...
4.5K

