Abstract: The keypoint to the treatment of acute ischemic stroke is to timely recanalize the occluded artery, restore blood flow in the ischemic tissue, and save the ischemic penumbra. Up to now, ...endovascular treatment represented by mechanical thrombectomy and stent implantation has become effective treatment for acute ischemic stroke, but hemorrhagic transformation is still a catastrophic complication of endovascular treatment, and is closely related to neurological deterioration and poor functional outcomes. Therefore, it is crucial for clinicians to deepen their understandings of hemorrhagic transformation. Based on the relevant guidelines and the latest studies, this paper aims to make a comprehensive review about hemorrhagic transformation after endovascular treatment of acute ischemic stroke, discusses the pathophysiological mechanism, risk factors, predictors and prevention and treatment strategies of hemorrhagic transformation, so as to provide reference for early prediction, prevention and treatment
电子轰击电离源(Electron impact ion source,EI)是一种真空中使用的高效电离源,其电离效率可达到0.1％,几乎可以电离所有的物质.近年来,电子轰击电离源-离子阱质谱(EI-ion trap mass ...spectrometry,EI-ITMS)的发展使得便携式气相色谱-质谱联用仪广泛应用于有毒有害物质的快速现场定性和定量检测.然而,EI-ITMS仪器的性能调试十分繁琐.首先,EI的离子传输效率需要设置合适的透镜电压提取系统,其次,EI电离会产生大量的碎片离子,为了保证最佳的质量范围,需要对离子阱质量分析器的相关电压参数不断进行微调.鉴于此,本研究基于自主研制的电子轰击离子源-离子阱质谱仪,建立了EI-ITMS的质量范围优化调试程序.所研制的EI电离源和离子阱质量分析器在轴向上串联,气体样品通过内径75μm的石英毛细管进入EI源后,产生的离子在提取电极系统的作用下加速、聚焦,再流向离子阱质量分析器,离子阱的前端盖电压作为门控,控制离子进入.对电子轰击源的各项参数进行了优化,并利用Simion软件模拟研究了实验条件下离子的运动轨迹和传输效率.所建立的EI-ITMS质量范围优化程序有助于缓解离子阱质量分析器的质量歧视效应,实现EI电离产生的小质量碎片分析.实验结果表明,利用所建立的程序可以实现丙酮的碎片离子m/z 43和全氟三丁胺的碎片离子m/z 414的检测.
