In a context of automation of cryo-electron microscopy, we developed a novel method for improving visibility of diffraction rings in the power spectra of cryo-electron micrographs of vitreous ice (without carbon film or high concentration of diffracting material). We used these enhanced spectra to semi-automatically detect and remove micrographs and/or local areas introducing errors in the global 3D map (drifted and charged areas) or those unable to increase global signal-to-noise ratio (non-diffracting areas). Our strategy also allows a detection of micrographs/areas with a strong astigmatism. These images should be removed when using algorithms that do not correct astigmatism. Our sorting method is simple and fast since it uses the normalized cross-correlation between enhanced spectra and their copies rotated by 90 degrees. It owes its success mainly to the novel pre-processing of power spectra. The improved visibility also allows an easier visual check of accuracy of sorting. We show that our algorithm can even improve the visibility of diffraction rings of cryo-electron micrographs of pure water. Moreover, we show that this visibility depends strongly on ice thickness. This algorithm is implemented in the Xmipp (open-source image processing package) and is freely available for implementation in any other software package.

译文

在冷冻电子显微镜自动化的背景下,我们开发了一种新颖的方法,用于提高玻璃冰冷冻电子显微照片 (没有碳膜或高浓度衍射材料) 的功率谱中衍射环的可见性。我们使用这些增强的光谱来半自动检测和删除显微照片和/或在全局3D地图中引入错误的局部区域 (漂移和带电区域) 或无法增加全局信噪比的区域 (非衍射区域)。我们的策略还允许检测具有强散光的显微照片/区域。当使用不校正散光的算法时,应删除这些图像。我们的排序方法简单,快速,因为它使用了旋转90度的增强光谱及其副本之间的归一化互相关。它的成功主要归功于功率谱的新颖预处理。改进的可见性还可以更轻松地视觉检查排序的准确性。我们证明,我们的算法甚至可以提高纯水的低温电子显微照片的衍射环的可见性。此外,我们表明这种能见度在很大程度上取决于冰的厚度。此算法在Xmipp (开源图像处理包) 中实现,并且可以免费在任何其他软件包中实现。

+1
+2
100研值 100研值 ¥99课程
检索文献一次
下载文献一次

去下载>

成功解锁2个技能,为你点赞

《SCI写作十大必备语法》
解决你的SCI语法难题!

技能熟练度+1

视频课《玩转文献检索》
让你成为检索达人!

恭喜完成新手挑战

手机微信扫一扫,添加好友领取

免费领《Endnote文献管理工具+教程》

微信扫码, 免费领取

手机登录

获取验证码
登录