A simple SI epidemic model with age of vaccination is discussed in this paper.Both vexing birth rate, the mortality rate caused by disease and vaccine waning rate areconsidered in this model. We prove that the global ...A simple SI epidemic model with age of vaccination is discussed in this paper.Both vexing birth rate, the mortality rate caused by disease and vaccine waning rate areconsidered in this model. We prove that the global dynamics is completely determined bythe basic reproductive number R（ψ）（ψ denotes per capita vaccination rate）. If R（0） 〈 1,the disease-free equilibrium is a global attractor; If R（ψ） 〈： 1, the disease-free equilibriumis locally asymptotically stable; If R（ψ） ：〉 1, an unique endemic equilibrium exists and islocally asymptotically stable under certain condition.展开更多
目的探讨冻干制剂乙型脑炎减毒活疫苗和液体制剂23价肺炎球菌多糖疫苗0~2℃条件下存放对其效价的影响。方法将冻干制剂乙型脑炎减毒活疫苗和液体制剂23价肺炎球菌多糖疫苗存放于0~2℃条件下一定时间后,与存放于2~8℃规定条件的制品进行...目的探讨冻干制剂乙型脑炎减毒活疫苗和液体制剂23价肺炎球菌多糖疫苗0~2℃条件下存放对其效价的影响。方法将冻干制剂乙型脑炎减毒活疫苗和液体制剂23价肺炎球菌多糖疫苗存放于0~2℃条件下一定时间后,与存放于2~8℃规定条件的制品进行疫苗效价的比较。结果1人份和5人份乙型脑炎减毒活疫苗在0~2℃条件下分别存放17 h 20 min和18 h 55 min,病毒滴度均符合5.7~7.1 lgPFU/ml的质量标准,且与存放于2~8℃规定条件的同批次疫苗比较,t值分别为0.26和0.28,P值均大于0.05,差异无统计学意义;23价肺炎球菌多糖疫苗在0~2℃条件下存放21 h 50 min,23个型别的多糖含量均符合35~65μg/ml的质量标准,且与存放于2~8℃规定条件的同批次疫苗比较,t值为0.01~2.25,P值均大于0.05,差异无统计学意义。结论冻干制剂乙型脑炎减毒活疫苗和液体制剂23价肺炎球菌多糖疫苗存放在0~2℃条件下的一定时间内,疫苗效价仍符合质量标准。展开更多
In this paper, an SEIR epidemic model with vaccination is formulated. The results of our mathematical analysis indicate that the basic reproduction number plays an important role in studying the dynamics of the system...In this paper, an SEIR epidemic model with vaccination is formulated. The results of our mathematical analysis indicate that the basic reproduction number plays an important role in studying the dynamics of the system. If the basic reproduction number is less than unity, it is shown that the disease-free equilibrium is globally asymptotically stable by comparison arguments. If it is greater than unity, the system is permanent and there is a unique endemic equilibrium. In this case, sufficient conditions are established to guarantee the global stability of the endemic equilibrium by the theory of the compound matrices. Numerical simulations are presented to illustrate the main results.展开更多
In this paper, an SIRS epidemic model with time delay and vaccination is investigated. By analyzing the corresponding characteristic equation, the local stability of diseasefree equilibrium of the model is established...In this paper, an SIRS epidemic model with time delay and vaccination is investigated. By analyzing the corresponding characteristic equation, the local stability of diseasefree equilibrium of the model is established. By constructing Lyapunov functional, sufficient conditions are established for the local stability of an endemic equilibrium of the model. Further, a threshold value is obtained. By using comparison arguments, it is proved when the threshold value is less than unity, the diseasefree equilibrium is globally asymptoti cally stable. When the threshold value is greater than unity, by using an iteration scheme and by constructing appropriate Lyapunov functional, respectively, sufficient conditions are derived for the global stability of the endemic equilibrium of the model. Numerical simulations are carried out to illustrate the theoretical results.展开更多
基金Supported by the NSF of China（10371105） Supported by the Youth Science Foundation of Xinyang Normal University（20060202）
文摘A simple SI epidemic model with age of vaccination is discussed in this paper.Both vexing birth rate, the mortality rate caused by disease and vaccine waning rate areconsidered in this model. We prove that the global dynamics is completely determined bythe basic reproductive number R（ψ）（ψ denotes per capita vaccination rate）. If R（0） 〈 1,the disease-free equilibrium is a global attractor; If R（ψ） 〈： 1, the disease-free equilibriumis locally asymptotically stable; If R（ψ） ：〉 1, an unique endemic equilibrium exists and islocally asymptotically stable under certain condition.
文摘目的探讨冻干制剂乙型脑炎减毒活疫苗和液体制剂23价肺炎球菌多糖疫苗0~2℃条件下存放对其效价的影响。方法将冻干制剂乙型脑炎减毒活疫苗和液体制剂23价肺炎球菌多糖疫苗存放于0~2℃条件下一定时间后,与存放于2~8℃规定条件的制品进行疫苗效价的比较。结果1人份和5人份乙型脑炎减毒活疫苗在0~2℃条件下分别存放17 h 20 min和18 h 55 min,病毒滴度均符合5.7~7.1 lgPFU/ml的质量标准,且与存放于2~8℃规定条件的同批次疫苗比较,t值分别为0.26和0.28,P值均大于0.05,差异无统计学意义;23价肺炎球菌多糖疫苗在0~2℃条件下存放21 h 50 min,23个型别的多糖含量均符合35~65μg/ml的质量标准,且与存放于2~8℃规定条件的同批次疫苗比较,t值为0.01~2.25,P值均大于0.05,差异无统计学意义。结论冻干制剂乙型脑炎减毒活疫苗和液体制剂23价肺炎球菌多糖疫苗存放在0~2℃条件下的一定时间内,疫苗效价仍符合质量标准。
基金This work was supported by the National Natural Science Foundation of China （11371368）, the Nature Science Foundation for Young Scientists of Hebei Province, China （A2013506012） and Basic Courses Department of Mechanical Engineering College Foundation （JCKY1507）.
文摘In this paper, an SEIR epidemic model with vaccination is formulated. The results of our mathematical analysis indicate that the basic reproduction number plays an important role in studying the dynamics of the system. If the basic reproduction number is less than unity, it is shown that the disease-free equilibrium is globally asymptotically stable by comparison arguments. If it is greater than unity, the system is permanent and there is a unique endemic equilibrium. In this case, sufficient conditions are established to guarantee the global stability of the endemic equilibrium by the theory of the compound matrices. Numerical simulations are presented to illustrate the main results.
文摘In this paper, an SIRS epidemic model with time delay and vaccination is investigated. By analyzing the corresponding characteristic equation, the local stability of diseasefree equilibrium of the model is established. By constructing Lyapunov functional, sufficient conditions are established for the local stability of an endemic equilibrium of the model. Further, a threshold value is obtained. By using comparison arguments, it is proved when the threshold value is less than unity, the diseasefree equilibrium is globally asymptoti cally stable. When the threshold value is greater than unity, by using an iteration scheme and by constructing appropriate Lyapunov functional, respectively, sufficient conditions are derived for the global stability of the endemic equilibrium of the model. Numerical simulations are carried out to illustrate the theoretical results.
