Optimal Treatment Strategy for Infectious Diseases with Two Treatment Stages

In this paper, a disease transmission model with two treatment stages is proposed and analyzed. The results indicate that the basic reproduction number is a critical threshold for the prevalence of the disease. If the basic reproduction number is less than one, the disease free equilibrium is globally asymptotically stable. Otherwise, the endemic equilibrium is globally asymptotically stable. Therefore, besides the basic reproduction number, a new marker for characterizing the seriousness of the disease, named as dynamical final infective size, is proposed, which differs from traditional final size because the proposed model includes the natural birth and death. Finally, optimization strategies for limited medical resources are obtained from the perspectives of basic reproduction number and dynamical final infective size, and the real-world disease management scenarios are given based on these finding.

Moderate papain addition improves the physicochemical,microbiological,flavor and sensorial properties of Chouguiyu,traditional Chinese fermented fish

The objective of this study was to investigate the effect of papain on the physicochemical and microbiological properties,volatile compound profiles,and sensorial attributes of Chouguiyu.Papain was applied at a dose of 10,50,200,400 U/g fish.Results showed that papain addition improved the release of free amino acids,essential amino acids,eicosapentaenoi acid(EPA,C20:5n3),and docosapentenoic acid(DPA,C22:5n6),respectively.Lower biogenic amines content,higher the volatile compound concentrations and relative abundance of Lactobacillales were also observed.Further results showed that the papain dose group decreased the fermentation time from 10 to 7 days while good organoleptic quality was remained,especially in the 200 U/g dose group.The redundancy analysis(RDA)showed a high correlation between Lactobacillus and the key volatile compounds in the 200 U/g and 400 U/g groups,which indicated that Lactobacillus could contribute to the fatty flavor.In summary,proper papain addition(i.e.200 U/g or 400 U/g)could reduce biogenic amines contents and maintain acceptable sensorial properties of Chouguiyu in a shorter fermentation time.