arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1007.0074physics.opticsphysics.atm-clusphysics.bio-ph
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X射线自由电子激光生物分子成像与电子损伤

Biomolecular imaging and electronic damage using X-ray free-electron lasers

Harry M. Quiney, Keith A. Nugent

摘要:

利用飞秒X射线自由电子激光(XFEL)脉冲从衍射实验确定生物分子结构的提议涉及实现衍射极限原子分辨率所需的入射亮度与由照射引起的电子和结构损伤之间的冲突。在这里,我们表明,之前对以这种方式获得生物分子结构的条件的估计具有过度的限制性,因为它们基于不适合所提出的相互作用条件的相干衍射模型。一个更详细的成像模型,来自光学相干理论和量子电动力学被证明是更宽容的电子损伤。核密度被用作分子结构的主要描述符。该方法的基础也可用于表征电动过程进行散射实验上的已知结构的复杂分子。

英文摘要:

Proposals to determine biomolecular structures from diffraction experiments using femtosecond X-ray free-electron laser (XFEL) pulses involve a conflict between the incident brightness required to achieve diffraction-limited atomic resolution and the electronic and structural damage induced by the illumination. Here we show that previous estimates of the conditions under which biomolecular structures may be obtained in this manner are unduly restrictive, because they are based on a coherent diffraction model that is not appropriate to the proposed interaction conditions. A more detailed imaging model derived from optical coherence theory and quantum electrodynamics is shown to be far more tolerant of electronic damage. The nuclear density is employed as the principal descriptor of molecular structure. The foundations of the approach may also be used to characterize electrodynamical processes by performing scattering experiments on complex molecules of known structure.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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