Facile identification of fluorosurfactant category in aqueous film-forming foam concentrates via optimized^(19)F NMR

Aqueous film-forming foams(AFFFs)are the primary source of toxic perfluoroalkyl and polyfluoroalkyl substances(PFAS)in wastewater.Thus,it is urgent to develop a facile and fast method for identifying fluorosurfactants in commercially available AFFFs.In this work,fluorine nuclear magnetic resonance(^(19)F NMR)spectroscopy was optimized to measure AFFFs directly with the extra addition of 5%D_(2)O as the locking reagent,and high-quality spectra could be acquired within 4 min(0.1%fluorosurfactant content).Recovery experiments demonstrated that the use of different AFFFs had no marked influence on the quantitative analysis of fluorosurfactants.Such method works with low-field NMR spectroscopy(1.4 T)as well.Two-dimensional(2D)^(19)F COSY NMR was used to make signal assignments for different fluorosurfactant derivatives.The optimized ^(19)F NMR could quantify the commercially available fluorosurfactants in different AFFFs,identify them being in either the perfluorooctane sulfonate(PFOS)or fluorotelomer sulfonic acid(FTS)categories,and distinguish the head-group of PFOS and FTS derivatives,which exhibits great potentials in the developments of relevant commercial detections.

Wireless electrical stimulation generated by piezoelectric nanomaterial promotes the dental pulp regeneration via regulating mitochondrial Ca^(2+)/PKA signaling pathway

The induction of dental pulp stem cells(DPSCs)into odontogenic differentiation is a cutting-edge method of dental pulp regeneration treatment.However,it remains a challenge to develop biomaterials and ther-apies that can induce odontogenic differentiation.Here,we propose a wireless electrical stimulation strat-egy to induce DPSCs odontogenic differentiation via K_(0.5)Na_(0.5)NbO_(3)piezoelectric nanoparticles(KNN)and polarized KNN(PKNN),which can be endocytosed by DPSCs.In vitro,several odontogenic differentiation indexes were also increased in DPSCs treated with KNN and PKNN,and the increase was more obvious in the PKNN group.Intracellular wireless electrical field promoted mitochondrial calcium concentration via mitochondrial calcium unidirectional transporter(MCU),increased the production of adenosine triphos-phate(ATP),and induced odontogenic differentiation through the activation of the cAMP-PKA signaling pathway.In vivo,dental pulp-like tissue was induced by electrical stimulation wirelessly with KNN and PKNN,which was more clinically friendly compared with the wired device,and the induction was more obvious in the PKNN group consistent with in vitro experiments.In conclusion,this work demonstrates the potential of PKNN as an effective stimulus that can induce odontogenic differentiation of DPSCs and be applied to dental pulp regeneration treatment.