Diclofenac sodium(DS) is a widely used nonsteroidal anti-inflammatory drug(NSAIDs).NSAIDs are poorly removed during standard wastewater treatment.The consequences of the presence of NSAIDs in rivers and lakes at 10-11...Diclofenac sodium(DS) is a widely used nonsteroidal anti-inflammatory drug(NSAIDs).NSAIDs are poorly removed during standard wastewater treatment.The consequences of the presence of NSAIDs in rivers and lakes at 10-11–10-8 mol/L are not yet established;therefore, ecotoxicologists have focused their efforts on studying the effect of lowconcentration NSAIDs on fish and hydrobionts, and also on predicting the potential risks to humans.Literature provides some information about the bioeffects of some NSAID solutions in low concentrations but there is no physicochemical explanation for these phenomena.Studying the physicochemical patterns of DS solutions in the low range of concentrations and establishing an interconnection between the solutions’ physicochemical properties and bioeffects can provide a conceptually new and important source of information regarding the unknown effects of DS.The physicochemical properties and action of DS solutions on Ceriodaphnia affinis cladocerans,Paramecium caudatum infusoria, Chlorella vulgaris unicellular green algae, as well as on the growth of the roots of Triticum vulgare wheat seeds, were studied in the calculated concentration range of 1 × 10-3–1 × 10-18 mol/L.The relationship between these phenomena was established using the certified procedures for monitoring the toxicity of natural water and wastewater.It was shown for the first time that water solutions of DS are dispersed systems in which the dispersed phase undergoes a rearrangement with dilution, accompanied by changes in its size and properties, which affects the nonmonotonic dependences of the system’s physicochemical properties and could cause nonmonotonic changes in action on hydrobionts in the low concentration range.展开更多
The frozen bodies of a young woolly mammoth(Mammuthus primigenius),a wild horse(Equus sp.)and a steppe bison(Bison priscus)were recently found in the northern Yakutia(northeastern Siberia).All specimens have preserved...The frozen bodies of a young woolly mammoth(Mammuthus primigenius),a wild horse(Equus sp.)and a steppe bison(Bison priscus)were recently found in the northern Yakutia(northeastern Siberia).All specimens have preserved bones,skin and soft tissues.Whereas the woolly mammoth and the Pleistocene horse were represented by partial frozen bodies,the steppe bison body was recovered in an absolutely complete state.All specimens were found frozen in the permafrost,with some of the tissues mummified.The wild horse and steppe bison are of Holocene age,and the mammoth is of Late Pleistocene age.展开更多
文摘Diclofenac sodium(DS) is a widely used nonsteroidal anti-inflammatory drug(NSAIDs).NSAIDs are poorly removed during standard wastewater treatment.The consequences of the presence of NSAIDs in rivers and lakes at 10-11–10-8 mol/L are not yet established;therefore, ecotoxicologists have focused their efforts on studying the effect of lowconcentration NSAIDs on fish and hydrobionts, and also on predicting the potential risks to humans.Literature provides some information about the bioeffects of some NSAID solutions in low concentrations but there is no physicochemical explanation for these phenomena.Studying the physicochemical patterns of DS solutions in the low range of concentrations and establishing an interconnection between the solutions’ physicochemical properties and bioeffects can provide a conceptually new and important source of information regarding the unknown effects of DS.The physicochemical properties and action of DS solutions on Ceriodaphnia affinis cladocerans,Paramecium caudatum infusoria, Chlorella vulgaris unicellular green algae, as well as on the growth of the roots of Triticum vulgare wheat seeds, were studied in the calculated concentration range of 1 × 10-3–1 × 10-18 mol/L.The relationship between these phenomena was established using the certified procedures for monitoring the toxicity of natural water and wastewater.It was shown for the first time that water solutions of DS are dispersed systems in which the dispersed phase undergoes a rearrangement with dilution, accompanied by changes in its size and properties, which affects the nonmonotonic dependences of the system’s physicochemical properties and could cause nonmonotonic changes in action on hydrobionts in the low concentration range.
基金The authors are grateful to the late Vasiliy Gorokhov,the head of the tribal community‘Yukagir’(who passed away in Nov 2012),and to the Yukagir community for allowing us to borrow the specimens for this study in Yakutsk,Russia.The Scientific Research Institute of Applied Ecology of the North of Northeastern Federal University,Yakutsk and Bernard Buigues(Saint-Jean de Lus,France)helped with the logistics and provided funds for the specimens to be transported to Yakutsk in 2012.
文摘The frozen bodies of a young woolly mammoth(Mammuthus primigenius),a wild horse(Equus sp.)and a steppe bison(Bison priscus)were recently found in the northern Yakutia(northeastern Siberia).All specimens have preserved bones,skin and soft tissues.Whereas the woolly mammoth and the Pleistocene horse were represented by partial frozen bodies,the steppe bison body was recovered in an absolutely complete state.All specimens were found frozen in the permafrost,with some of the tissues mummified.The wild horse and steppe bison are of Holocene age,and the mammoth is of Late Pleistocene age.
