The COVID-19 pandemic highlighted the urgent need to control airborne virus transmission,particularly in indoor environments with limited ventilation.This study evaluates the effectiveness of UVA and UVC irradiation,a...The COVID-19 pandemic highlighted the urgent need to control airborne virus transmission,particularly in indoor environments with limited ventilation.This study evaluates the effectiveness of UVA and UVC irradiation,along with hydrogen peroxide(H_(2)O_(2)),in inactivating aerosolized viruses.A 19 m^(3)virus aerosol simulation chamber,replicating indoor conditions,was used to simulate human respiratory emissions by aerosolizing Escherichia phage T4(T4 phages)embedded in a pig mucin medium that mimics respiratory aerosols.Results showed a clear,dose-dependent reduction in viral genome copies with UVC exposure,where a dose of 129.9 mJ/cm^(2)reduced over 99%of the viral genome copies.Although less efficient,UVA still contributed to virus inactivation,reducing detectable phages to 20%at 513.30 J/cm^(2).Mucin provided a protective effect,making virus removal more challenging.Hydrogen peroxide enhanced disinfection,with 1.6 ppm reducing viral genome copies by 78%,and higher concentrations(up to 16 ppm)achieving over 99%reduction in the dark condition.The combination of UVA/UVC with H_(2)O_(2)further enhanced disinfection,eliminating detectable virus genome copies entirely.These findings underscore the potential for using combined UV light and chemical treatments to effectively mitigate airborne viral transmission in enclosed spaces.展开更多
The attractiveness and efficacy of four anonymous anticoagulant-free alternative rodenticides(active ingredients cellulose or plaster)were tested on wild strain groups of house mice(Mus musculus Linnaeus)and brown rat...The attractiveness and efficacy of four anonymous anticoagulant-free alternative rodenticides(active ingredients cellulose or plaster)were tested on wild strain groups of house mice(Mus musculus Linnaeus)and brown rats(Rattus norvegicus Berkenhout)in laboratory choice and no-choice experiments.In no-choice tests,the rodenticide product was offered ad libitum to the animals for 21 days(mice)and 10 days(rats),respectively.In choice tests,the rodenticide product and non-poisoned food were offered for 28 days(mice)and 14 days(rats).Two products with cellulose(C1 and C2)as the active ingredient were tested against both mice and rats.In two no-choice tests with mice,all animals died within 14 days(C1)and 21 days(C2);in a third no-choice test,11%(2/18)of mice survived(C1:21 days).In all three tests,numerous incidents of cannibalism were observed.The attractiveness of cellulose baits was tested for one product(C1)in three trials against normal food pellets.In all trials,bait consumption was low and all mice survived(15-34 days).Two no-choice trials with cellulose baits(C1)were conducted on groups of Rattus norvegicus;11 of 12 rats survived the bait feeding period and no cannibalism or sign of aggression between conspecifics was observed.Two plaster-based(CaSO_(4)·0.5H_(2)O)products(P1 and P2)were tested against both mice and rats;in no-choice tests,only one mouse(n=20)and no rats(n=8)were killed,although the baits proved to be attractive for rats and mice in choice tests.The results of these experiments suggest that neither cellulose-based nor plaster-based rodenticides are suitable agents for the control of Mus musculus and Rattus norvegicus.展开更多
基金supported by the Federal Ministry of Education and Research(BMBF)under project number 13GW0597E(BeCoLe main project,with subprojects KAPAVIR and MikroVirasol)the Deutsche Forschungsgemeinschaft(DFG,German Research Foundation)under project number 468717405(AEROVIR)supported by European Regional Development Funds(EFRE)and the Helmholtz Association for using its microanalytical facilities.
文摘The COVID-19 pandemic highlighted the urgent need to control airborne virus transmission,particularly in indoor environments with limited ventilation.This study evaluates the effectiveness of UVA and UVC irradiation,along with hydrogen peroxide(H_(2)O_(2)),in inactivating aerosolized viruses.A 19 m^(3)virus aerosol simulation chamber,replicating indoor conditions,was used to simulate human respiratory emissions by aerosolizing Escherichia phage T4(T4 phages)embedded in a pig mucin medium that mimics respiratory aerosols.Results showed a clear,dose-dependent reduction in viral genome copies with UVC exposure,where a dose of 129.9 mJ/cm^(2)reduced over 99%of the viral genome copies.Although less efficient,UVA still contributed to virus inactivation,reducing detectable phages to 20%at 513.30 J/cm^(2).Mucin provided a protective effect,making virus removal more challenging.Hydrogen peroxide enhanced disinfection,with 1.6 ppm reducing viral genome copies by 78%,and higher concentrations(up to 16 ppm)achieving over 99%reduction in the dark condition.The combination of UVA/UVC with H_(2)O_(2)further enhanced disinfection,eliminating detectable virus genome copies entirely.These findings underscore the potential for using combined UV light and chemical treatments to effectively mitigate airborne viral transmission in enclosed spaces.
文摘The attractiveness and efficacy of four anonymous anticoagulant-free alternative rodenticides(active ingredients cellulose or plaster)were tested on wild strain groups of house mice(Mus musculus Linnaeus)and brown rats(Rattus norvegicus Berkenhout)in laboratory choice and no-choice experiments.In no-choice tests,the rodenticide product was offered ad libitum to the animals for 21 days(mice)and 10 days(rats),respectively.In choice tests,the rodenticide product and non-poisoned food were offered for 28 days(mice)and 14 days(rats).Two products with cellulose(C1 and C2)as the active ingredient were tested against both mice and rats.In two no-choice tests with mice,all animals died within 14 days(C1)and 21 days(C2);in a third no-choice test,11%(2/18)of mice survived(C1:21 days).In all three tests,numerous incidents of cannibalism were observed.The attractiveness of cellulose baits was tested for one product(C1)in three trials against normal food pellets.In all trials,bait consumption was low and all mice survived(15-34 days).Two no-choice trials with cellulose baits(C1)were conducted on groups of Rattus norvegicus;11 of 12 rats survived the bait feeding period and no cannibalism or sign of aggression between conspecifics was observed.Two plaster-based(CaSO_(4)·0.5H_(2)O)products(P1 and P2)were tested against both mice and rats;in no-choice tests,only one mouse(n=20)and no rats(n=8)were killed,although the baits proved to be attractive for rats and mice in choice tests.The results of these experiments suggest that neither cellulose-based nor plaster-based rodenticides are suitable agents for the control of Mus musculus and Rattus norvegicus.
