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SARS-CoV-2 Omicron variant is highly transmissible and extensive morbidity, which has raised concerns for antiviral therapy. In addition, the molecular basis for the attenuated pathogenicity and replication capacity of Omicron remains elusive. Here, we report for the first time that a high-frequency mutation T9I on 2-E of SARS-CoV-2 variant Omicron forms a non-selective ion channel with abolished calcium permeability and reduced acid sensitivity compared to the WT channel. In addition, T9I caused less cell death and a weaker cytokine production. The channel property changes might be responsible for the Omicron variant releases less efficiently and induces a comparatively lower level of cell damage in the infected cells. Our study gives valuable insights into key features of the Omicron variant, further supporting 2-E is a promising drug target against SARS-CoV-2 and providing critical information for the COVID-19 treatment.
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Objective:To establish a headspace capillary gas chromatography method for the determination of residual solvents in erlotinib hydrochloride .Methods:A DB-624 capillary column (30 m ×0.53 mm, 3.0 μm) was used and the carrier gas was nitro-gen.The flow rate was 2.0 ml· min-1 and the inlet temperature was 190℃.The FID detector temperature was 230 ℃.The column temperature program was with the initial temperature of 35℃( maitaining 8 min) , risen to 170℃with the rate of 28℃· min-1 ( main-taining 8 min) , and then risen to 200℃with the rate of 32℃· min-1 ( maintaining 7 min) .The headspace vial temperature was 100℃and the time was 30 min.Results:Ethanol, isopropanol, methylene chloride and n-butanol had a good linear relationship within the range of 0.68-409.14 μg· ml-1 (r=0.999 8),0.67-404.88 μg· ml-1 (r=0.999 8),1.71-51.31μg· ml-1 (r=0.999 7) and 0.72-431.12 μg· ml-1(r=0.999 8), respectively.The average recovery was 99.0% (RSD=0.41%, n=9), 100.2%(RSD=0.52%, n=9),97.1%(RSD=1.75%, n =9) and 102.5% (RSD=1.08%, n=9), respectively.Conclusion: The method is simple and accurate , which can be used for the determination of four residual organic solvents in erlotinib hydrochloride .
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Objective:To establish an HPLC method for the determination of calcium disodium edetate in fosaprepitant dimeglu-mine for injection. Methods:The chromatographic column was Agilent Zorbax Eclipse XDB C18(250 mm ×4.6 mm,5μm). The mo-bile phase consisted of 0. 2% tetrabutylammonium hydroxide(adjusting pH to 4. 0 with phosphoric acid)-acetonitrile(85∶15). The flow rate was 1. 0 ml·min-1 . The detection wavelength was 254 nm. The chromatographic column temperature was 35℃. The injection volume was 20μl. Results:The calibration curve was linear within the range of 26. 06-104. 24μg·ml-1(r=0. 999 8) for calcium di-sodium edetate. The average recovery was 99. 51% (RSD=0. 25%, n=9). Conclusion: The method is simple, rapid, accurate, specific and reproducible, and can be used in the determination of calcium disodium edetate in fosaprepitant dimeglumine for injection.
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Congenital pelvi-uretedc junction obstruction in children with congenital hydronephrosis is the most common etiology,but its pathogenesis is poorly understood in the past.With the development and application of genetic molecular biology techniques,the development of the ureter is clarified from molecular biological mechanism,and people have more in-depth understanding of the occurrence of the pelvi-ureteric junction obstruction at the level of gene molecular biology.