Pollution from road traffic contributes significantly to air pollution through pollutants from exhaust emissions(gases and particles)and non-exhaust emissions(tire wear particles,brake wear particles and the resuspens...Pollution from road traffic contributes significantly to air pollution through pollutants from exhaust emissions(gases and particles)and non-exhaust emissions(tire wear particles,brake wear particles and the resuspension of road dust).This research examined the hazard of tire particles(TP)and in particular evaluated the effect of TP size on lung macrophages.TP were obtained by cryogenic grinding of a tire and subsequent sieving to obtain four groups of particles(TP70,TP30,TP15,TP5)of different sizes with average diameters of 107μm,55μm,22μm,and 6μm,respectively.A complete physicochemical characterization was performed to determine the size distribution,chemical composition and morphology of these particles.We then investigated the proinflammatory response,oxidative stress and cytotoxicity induced in RAW264.7 cells exposed to four different TP concentrations for 24 h.TP had no direct effect on cytotoxicity,nor did they increase reactive oxygen species(ROS)production in the cells.However,TP induced a significant and size-dependent proinflammatory effect,which was particularly pronounced with small particles.Moreover,this effect was concentration-dependent.展开更多
Management of discarded tires is a compelling environmental issue worldwide.Although there are several approaches developed to recycle waste tire rubbers,their application in solid-state cooling is still unexplored.Co...Management of discarded tires is a compelling environmental issue worldwide.Although there are several approaches developed to recycle waste tire rubbers,their application in solid-state cooling is still unexplored.Considering the high barocaloric potential verified for elastomers,the use of waste tire rubber(WTR)as a refrigerant in solid-state cooling devices is very promising.Herein,we investigated the barocaloric effects in WTR and polymer blends made of vulcanized natural rubber(VNR)and WTR,to evaluate its feasibility for solid-state cooling technologies.The adiabatic temperature changes and the isothermal entropy changes reach giant values,as well as the performance parameters,being comparable or even better than most barocaloric materials in literature.Moreover,pure WTR and WTR-based samples also present a faster thermal exchange than VNR,consisting of an additional advantage of using these discarded materials.Thus,the present findings evidence the encouraging perspectives of employing waste rubbers in solid-state cooling based on barocaloric effects,contributing to both the recycling of polymers and the sustainable energy technology field.展开更多
基金supported by the Ecole des Mines Saint-Etienne and the Agence de l’Environnement et de la Maitrise de l’Energie。
文摘Pollution from road traffic contributes significantly to air pollution through pollutants from exhaust emissions(gases and particles)and non-exhaust emissions(tire wear particles,brake wear particles and the resuspension of road dust).This research examined the hazard of tire particles(TP)and in particular evaluated the effect of TP size on lung macrophages.TP were obtained by cryogenic grinding of a tire and subsequent sieving to obtain four groups of particles(TP70,TP30,TP15,TP5)of different sizes with average diameters of 107μm,55μm,22μm,and 6μm,respectively.A complete physicochemical characterization was performed to determine the size distribution,chemical composition and morphology of these particles.We then investigated the proinflammatory response,oxidative stress and cytotoxicity induced in RAW264.7 cells exposed to four different TP concentrations for 24 h.TP had no direct effect on cytotoxicity,nor did they increase reactive oxygen species(ROS)production in the cells.However,TP induced a significant and size-dependent proinflammatory effect,which was particularly pronounced with small particles.Moreover,this effect was concentration-dependent.
基金The authors acknowledge financial support from FAPESP(No.2012/03480-0),CNPq and CAPES.The authors also thank LNLS and CNPEM.
文摘Management of discarded tires is a compelling environmental issue worldwide.Although there are several approaches developed to recycle waste tire rubbers,their application in solid-state cooling is still unexplored.Considering the high barocaloric potential verified for elastomers,the use of waste tire rubber(WTR)as a refrigerant in solid-state cooling devices is very promising.Herein,we investigated the barocaloric effects in WTR and polymer blends made of vulcanized natural rubber(VNR)and WTR,to evaluate its feasibility for solid-state cooling technologies.The adiabatic temperature changes and the isothermal entropy changes reach giant values,as well as the performance parameters,being comparable or even better than most barocaloric materials in literature.Moreover,pure WTR and WTR-based samples also present a faster thermal exchange than VNR,consisting of an additional advantage of using these discarded materials.Thus,the present findings evidence the encouraging perspectives of employing waste rubbers in solid-state cooling based on barocaloric effects,contributing to both the recycling of polymers and the sustainable energy technology field.
