动态线纺聚乙烯醇/海藻酸钠纳米纤维膜的制备

为了实现静电纺纳米纤维产量化的制备,使用自主设计的无针式动态线性电极静电纺丝机制备聚乙烯醇(PVA)/海藻酸钠(SA)(AP)纳米纤维膜。采用扫描电子显微镜(SEM)研究PVA/SA配比、收集距离和纺丝电压对纤维形貌及直径分布的影响。结果表明,PVA/SA配比对纤维形貌影响最大,随着SA含量降低,溶液牵伸顺利;在此基础上随着距离增加,纤维形貌逐渐改善但不匀率有所增加。当7.5%PVA与2%SA按体积比9∶1共混时,所得纤维形貌及直径分布最佳,最佳纺丝电压和距离分别为75 kV和25 cm,纤维平均直径为(187±44)nm,产量可达2.5 g/h。为AP纳米纤维膜的规模化制备提供了参考。

Rapid screening of SARS-CoV-2 inhibitors via ratiometric fluorescence of RBD–ACE2 complexes in living cells by competitive binding

To the Editor:The current coronavirus disease-19(COVID-19)pandemic spurs the development of antiviral drugs for SARS-CoV-2,as the number of patients with viral infections continues to rise globally in the context of widespread vaccination.Targeting the interaction between the receptor binding domain(RBD)of SARS-CoV-2 spike protein and the host cell ACE2 is a promising therapeutic strategy to effectively inhibit viral entry.