RESUMEN
As tuberculosis (TB) patients do not have lifetime immunity, environmental transmission is one of the key reasons why TB has not been entirely eradicated. In this study, an SVEIRB model of recurrent TB considering environmental transmission was developed to explore the transmission kinetics of recurrent TB in the setting of environmental transmission, exogenous infection, and prophylaxis. A more thorough explanation of the effect of environmental transmission on recurrent TB can be found in the model's underlying regeneration numbers. The global stability of disease-free and local equilibrium points can be discussed by looking at the relevant characteristic equations. The Lyapunov functions and the LaSalle invariance principle are used to show that the local equilibrium point is globally stable, and TB will persist if the basic reproduction number is larger. Conversely, the disease will disappear if the basic reproduction number is less than one. The impact of environmental transmission on the spread of tuberculosis was further demonstrated by numerical simulations, which also demonstrated that vaccination and reducing the presence of the virus in the environment are both efficient approaches to control the disease's spread.
RESUMEN
A novel electrochemical sensor is reported for the detection of the antiviral drug favipiravir based on the core-shell nanocomposite of flower-like molybdenum disulfide (MoS2) nanospheres and molecularly imprinted polymers (MIPs). The MoS2@MIP core-shell nanocomposite was prepared via the electrodeposition of a MIP layer on the MoS2 modified electrode, using o-phenylenediamine as the monomer and favipiravir as the template. The selective binding of target favipiravir at the MoS2@MIP core-shell nanocomposite produced a redox signal in a concentration dependent manner, which was used for the quantitative analysis. The preparation process of the MoS2@MIP core-shell nanocomposite was optimized. Under the optimal conditions, the sensor exhibited a wide linear response range of 0.01 ~ 100 nM (1.57*10-6 ~ 1.57*10-2 µg mL-1) and a low detection limit of 0.002 nM (3.14*10-7 µg mL-1). Application of the sensor was demonstrated by detecting favipiravir in a minimum amount of 10 µL biological samples (urine and plasma). Satisfied results in the recovery tests indicated a high potential of favipiravir monitoring in infectious COVID-19 samples.