Objective To develop a gel permeation chromatography method for determination of content and molecular weight ( Mw ) of Mussel Polysaccharide.Methods Using GPC method, the sample was separated with TSK-gel GMPWXL(7.8 mm ×300 mm) chromatography column which was set at 35℃.The mobile phase was 0.05 mol/mL NaNO3(including 0.05%Na2N3) and the flow rate was 0.6 mL/min.The detector was RID-20AT. Results The average molecular weight of the polysaccharide of Mytilus coruscus was 1 261 411 and the average content was 88.6%by using of the calibration curves of dextrans.The average molecular weight of the polysaccharide of Mytilus edulis was 1 244 062 and the average content was 87.4%. Conclusion The method established in this paper is simple and rapid, accurate and reproducible, which can be used for the quality control of Mussel Polysaccharide.

The diagnosis of cerebral small vessel disease (CSVD) is highly dependent on neuroimaging, and its imaging changes include lacune, lacunar infarction, white matter hyperintensity (WMH), perivascular space (PVS), cerebral microbleed, etc. In previous studies, the definitions of these imaging changes were quite different, resulting in misdiagnosis of lacuna, WMH and PVS. This comment will summarize the clinical, imaging, and pathological characteristics of CSVD, sort out the process and effectiveness of the gradually normalized diagnostic standards, and propose errors that should be avoided, aiming to improve the accuracy and consistency of clinical diagnosis and research.