To describe the interaction between viral infection and immune response,we establish a mathematical model with intracellular delay and investigate an optimal control problem to examine the effect of antiviral therapy....To describe the interaction between viral infection and immune response,we establish a mathematical model with intracellular delay and investigate an optimal control problem to examine the effect of antiviral therapy.Dynamic analysis of the proposed model for the stability of equilibria and Hopf bifurcation is conducted.Theoretical results reveal that the dynamical properties are determined by both the immune-inactivated reproduction number and the immune-activated reproduction number.With the aim of minimizing the infected cells and viral load with consideration for the treatment costs,the optimal solution is discussed analytically.Numerical simulations are performed to suggest the optimal therapeutic strategy and compare the model-predicted consequences.展开更多
This paper deals with the global dynamics of a tuberculosis(TB)model with agestructure and delay.We perform some rigorous analyses for the model,including presenting an explicit formula for the basic reproduction numb...This paper deals with the global dynamics of a tuberculosis(TB)model with agestructure and delay.We perform some rigorous analyses for the model,including presenting an explicit formula for the basic reproduction number of the model,addressing the persistence of the solution semi-flow and the existence of the global attractor.Based on these analyses,we establish some results on stability and instability of equilibrium of the system.Finally,some numerical examples are provided to illustrate our obtained results.展开更多
Three immunizing haptens of bisphenol A(BPA), including two new haptens, were used to produce highly sensitive and specific polyclonal antibodies. The spacer arms of haptens for coupling to the protein carrier were lo...Three immunizing haptens of bisphenol A(BPA), including two new haptens, were used to produce highly sensitive and specific polyclonal antibodies. The spacer arms of haptens for coupling to the protein carrier were located at different positions in BPA, and different length spacer arms were tested. Highly sensitive polyclonal antibodies were obtained and characterized using indirect competitive enzyme-linked immunosorbent assay(ic ELISA). Under optimized conditions, the half maximal inhibitory concentration(IC50) value of the best polyclonal antibody was 2.1 mg·L^(-1), based on coating heterogeneous antigens, and this optimal polyclonal antibody was highly sensitive toward BPA and displayed negligible crossreactivity with bisphenol B and bisphenol E. A sensitive ic ELISA method utilizing the polyclonal antibody was developed for the determination of BPA in milk. In spiked samples(5, 10 and 20 mg·L^(-1)), the recovery ranged from 80% to 102% with a coefficient of variation(CV) value below 15.8%. The limit of detection of ic ELISA was1.95 mg·L^(-1). These results indicate that the ic ELISA method is suitable for the detection of BPA in milk.展开更多
基金supported by National Natural Science Foundation of China (#11801439)Natural Science Basic Research Plan in Shaanxi Province of China Grant (#2022JM-038)。
文摘To describe the interaction between viral infection and immune response,we establish a mathematical model with intracellular delay and investigate an optimal control problem to examine the effect of antiviral therapy.Dynamic analysis of the proposed model for the stability of equilibria and Hopf bifurcation is conducted.Theoretical results reveal that the dynamical properties are determined by both the immune-inactivated reproduction number and the immune-activated reproduction number.With the aim of minimizing the infected cells and viral load with consideration for the treatment costs,the optimal solution is discussed analytically.Numerical simulations are performed to suggest the optimal therapeutic strategy and compare the model-predicted consequences.
基金supported by the National Infect ious Disease Science and Technology Major Project Grant 2017ZX10201302-007by the National Natural Science Foun-dation of China(Grant Nos.11926328,11926329,11971281 and 11501443)+2 种基金by the Natural Science Basic Research Plan in Shaanxi Province of China Grant 2020JQ-693by the Natural Science Foundation of Shaanxi Provincial Department of Education Grant 18JK0092supported by the NUPTSF(Grant No.NY220093).
文摘This paper deals with the global dynamics of a tuberculosis(TB)model with agestructure and delay.We perform some rigorous analyses for the model,including presenting an explicit formula for the basic reproduction number of the model,addressing the persistence of the solution semi-flow and the existence of the global attractor.Based on these analyses,we establish some results on stability and instability of equilibrium of the system.Finally,some numerical examples are provided to illustrate our obtained results.
基金supported by the National Natural Science Foundation of China (31622057)
文摘Three immunizing haptens of bisphenol A(BPA), including two new haptens, were used to produce highly sensitive and specific polyclonal antibodies. The spacer arms of haptens for coupling to the protein carrier were located at different positions in BPA, and different length spacer arms were tested. Highly sensitive polyclonal antibodies were obtained and characterized using indirect competitive enzyme-linked immunosorbent assay(ic ELISA). Under optimized conditions, the half maximal inhibitory concentration(IC50) value of the best polyclonal antibody was 2.1 mg·L^(-1), based on coating heterogeneous antigens, and this optimal polyclonal antibody was highly sensitive toward BPA and displayed negligible crossreactivity with bisphenol B and bisphenol E. A sensitive ic ELISA method utilizing the polyclonal antibody was developed for the determination of BPA in milk. In spiked samples(5, 10 and 20 mg·L^(-1)), the recovery ranged from 80% to 102% with a coefficient of variation(CV) value below 15.8%. The limit of detection of ic ELISA was1.95 mg·L^(-1). These results indicate that the ic ELISA method is suitable for the detection of BPA in milk.
