HIV testing and contact tracing facilitate early detection of HIV/AIDS infections for interrupting the hidden transmission.In this study,a susceptible-undiagnosed-diagnosed transmission model with testing and contact ...HIV testing and contact tracing facilitate early detection of HIV/AIDS infections for interrupting the hidden transmission.In this study,a susceptible-undiagnosed-diagnosed transmission model with testing and contact tracing is proposed in heterosexual and homosexual populations.The basic reproduction number,the heterosexual-transmission and homosexual-transmission reproduction numbers of the transmission model are derived by the next generation matrix method.The optimal-fitting results present that the basic reproduction number of Fujian 2012-2022 HIV/AIDS epidemics ranges from 1.93 to 2.74 by phases,which is consistent with the heterosexual-transmission reproduction number.The optimal fittings and the global sensitivity analysis show that the transmission risk mainly originates from the heterosexual contacts.The transmission risk assessments and the 2023-2035 tendency predictions are performed for HIV/AIDS prevalence in Fujian Province by scenarios.The numerical simulation results point out that the decrease of female-to-male transmission rate,the decline of proportion of active diagnosed population,and the reduction of the awareness delay,are the main contributors for declining HIV/AIDS prevalence.The 2023-2035 tendency predictions of Fujian Province reveal that,when the awareness delay is fixed,the rising trends of the infection scales caused by the transmission rates are more significant than those caused by the proportion of active diagnosed population.According to the transmission risk assessments and the tendency prediction results,several suggestions are provided to the policymakers for curbing the HIV/AIDS transmission in Fujian Province.展开更多
Three tracing tests from the same injection point executed at low, medium, and high water levels in the karst aquifer near Tianshengan village, Lunan Stone Forest, Yunnan Province, China, have revealed the basic prope...Three tracing tests from the same injection point executed at low, medium, and high water levels in the karst aquifer near Tianshengan village, Lunan Stone Forest, Yunnan Province, China, have revealed the basic properties of underground water flow. They showed the general directions of water flows; tracer concentrations were observed at six successive points allowing for the calculation of apparent dominant flow velocities at these sections towards the Dalongtan karst spring. For the high water level, the discharge between single sections was between two and 10 times greater than that at low water level. For the medium water level, the flow velocity at different sections was between 1.4 and 3.7 times faster than that at low water level; and for high water level, it was between 1.3 and 2.7 times faster than that at medium water level. The fastest water flow appeared at the first section （23 cm/s at medium water level）; and the slowest （0.6 cm/s at low water level） appeared where water flow must cross the Tianshengan fault （north-south direction）, and later, a layer of 20-30 m thickness of quartz sandstone and shale clay-stones. It was also possible to calculate the recovery of the tracer for point 4, Dakenyan, where discharge was measured. At the medium water level, 50% of the injected tracer was detected a half-day after its first appearance and at low water level after more than 3 days. The previously published research illustrates the transport velocities of possible contaminants and their solubilities in water at different hydrological conditions.展开更多
基金supported by Fujian Research and Training Grants for Young and Middle-Aged Leaders in Healthcare(202501140018)supported by National Natural Science Foundation of China(12231012)supported by The Major Health Research Project of Fujian Province(2021ZD01001).
文摘HIV testing and contact tracing facilitate early detection of HIV/AIDS infections for interrupting the hidden transmission.In this study,a susceptible-undiagnosed-diagnosed transmission model with testing and contact tracing is proposed in heterosexual and homosexual populations.The basic reproduction number,the heterosexual-transmission and homosexual-transmission reproduction numbers of the transmission model are derived by the next generation matrix method.The optimal-fitting results present that the basic reproduction number of Fujian 2012-2022 HIV/AIDS epidemics ranges from 1.93 to 2.74 by phases,which is consistent with the heterosexual-transmission reproduction number.The optimal fittings and the global sensitivity analysis show that the transmission risk mainly originates from the heterosexual contacts.The transmission risk assessments and the 2023-2035 tendency predictions are performed for HIV/AIDS prevalence in Fujian Province by scenarios.The numerical simulation results point out that the decrease of female-to-male transmission rate,the decline of proportion of active diagnosed population,and the reduction of the awareness delay,are the main contributors for declining HIV/AIDS prevalence.The 2023-2035 tendency predictions of Fujian Province reveal that,when the awareness delay is fixed,the rising trends of the infection scales caused by the transmission rates are more significant than those caused by the proportion of active diagnosed population.According to the transmission risk assessments and the tendency prediction results,several suggestions are provided to the policymakers for curbing the HIV/AIDS transmission in Fujian Province.
文摘Three tracing tests from the same injection point executed at low, medium, and high water levels in the karst aquifer near Tianshengan village, Lunan Stone Forest, Yunnan Province, China, have revealed the basic properties of underground water flow. They showed the general directions of water flows; tracer concentrations were observed at six successive points allowing for the calculation of apparent dominant flow velocities at these sections towards the Dalongtan karst spring. For the high water level, the discharge between single sections was between two and 10 times greater than that at low water level. For the medium water level, the flow velocity at different sections was between 1.4 and 3.7 times faster than that at low water level; and for high water level, it was between 1.3 and 2.7 times faster than that at medium water level. The fastest water flow appeared at the first section （23 cm/s at medium water level）; and the slowest （0.6 cm/s at low water level） appeared where water flow must cross the Tianshengan fault （north-south direction）, and later, a layer of 20-30 m thickness of quartz sandstone and shale clay-stones. It was also possible to calculate the recovery of the tracer for point 4, Dakenyan, where discharge was measured. At the medium water level, 50% of the injected tracer was detected a half-day after its first appearance and at low water level after more than 3 days. The previously published research illustrates the transport velocities of possible contaminants and their solubilities in water at different hydrological conditions.
