采用碱性蛋白酶和中性蛋白酶双酶分步水解法从羊骨中提取羊骨生物活性肽(sheep bone bioactive peptides,SBBP),本研究评估了其结构、氨基酸组成、分子质量分布及黄嘌呤氧化酶抑制活性。结果表明,双酶分步水解改变了羊骨蛋白的二级结构...采用碱性蛋白酶和中性蛋白酶双酶分步水解法从羊骨中提取羊骨生物活性肽(sheep bone bioactive peptides,SBBP),本研究评估了其结构、氨基酸组成、分子质量分布及黄嘌呤氧化酶抑制活性。结果表明,双酶分步水解改变了羊骨蛋白的二级结构,所制备的SBBP富含疏水性氨基酸、芳香族氨基酸和碱性氨基酸,且<1000 Da的肽段占比高达94.48%。SBBP在体外显示出黄嘌呤氧化酶抑制作用(半抑制浓度为14.27 mg/mL)。在高尿酸血症小鼠模型中,SBBP通过抑制黄嘌呤氧化酶和腺苷脱氨酶活性,显著降低血清尿酸、肌酐和尿素氮水平,并减轻肾脏组织病理学损伤。研究表明,SBBP具备预防和缓解高尿酸血症的潜力。展开更多
In view of the deficiencies in aspects such as failure rate requirements and analysis assumptions of advisory circular,this paper investigates the sources of high safety requirements,and the top-down design method for...In view of the deficiencies in aspects such as failure rate requirements and analysis assumptions of advisory circular,this paper investigates the sources of high safety requirements,and the top-down design method for the flight control system life cycle.Correspondingly,measures are proposed,including enhancing the safety target value to 10^(−10)per flight hour and implementing development assurance.In view of the shortcomings of mainstream aircraft flight control systems,such as weak backup capability and complex fault reconfiguration logic,improvements have been made to the system’s operating modes,control channel allocation,and common mode failure mitigation schemes based on the existing flight control architecture.The flight control design trends and philosophies have been analyzed.A flight control system architecture scheme is proposed,which includes three operating modes and multi-level voters/monitors,three main control channels,and a backup system independent of the main control system,which has been confirmed through functional modeling simulations.The proposed method plays an important role in the architecture design of safety-critical flight control system.展开更多
文摘In view of the deficiencies in aspects such as failure rate requirements and analysis assumptions of advisory circular,this paper investigates the sources of high safety requirements,and the top-down design method for the flight control system life cycle.Correspondingly,measures are proposed,including enhancing the safety target value to 10^(−10)per flight hour and implementing development assurance.In view of the shortcomings of mainstream aircraft flight control systems,such as weak backup capability and complex fault reconfiguration logic,improvements have been made to the system’s operating modes,control channel allocation,and common mode failure mitigation schemes based on the existing flight control architecture.The flight control design trends and philosophies have been analyzed.A flight control system architecture scheme is proposed,which includes three operating modes and multi-level voters/monitors,three main control channels,and a backup system independent of the main control system,which has been confirmed through functional modeling simulations.The proposed method plays an important role in the architecture design of safety-critical flight control system.
