Experimental Study on Enhanced Electrokinetic Remediation of Heavy Metal-contaminated Soil

In order to improve the efficiency of traditional electrokinetic remediation method of heavy metal-contaminated soil, cadmium-contaminated soil was remediated by two enhanced electrokinetic techniques, namely, the approaching anode method and intermittent current method. The remediation effect was verified under the conditions that the electric field strength was 2 V/cm, 0.1 mol/L citric acid was used as the electrolyte, and the remediation reaction time was 96 h. The results showed that for the approaching anode method, when the average electromigration distance was 5.48, the removal rate was 88.12%, which was 10.47% higher than the unenhanced technique, and the energy consumption per unit volume was 7.36 kWh/m^3;and as to the intermittent current method, the removal rate was 80.81%, and the energy consumption per unit volume was 8.12 kWh/m^3, which was relatively reduced by 33.07%. After the remediation, the proportions of the weak acid extractive form and reducible form of calcium decreased, and the proportions of the oxidizable form and residual form of cadmium did not change significantly.

Photothermal therapy with regulated Nrf2/NF-κB signaling pathway for treating bacteria-induced periodontitis

Periodontitis is an inflammatory disease initiated by bacterial infection,developed by excessive immune response,and aggravated by high level of reactive oxygen species(ROS).Hence,herein,a versatile metal-organic framework(MOF)-based nanoplatform is prepared using mesoporous Prussian blue(MPB)nanoparticles to load BA,denoted as MPB-BA.The established MPB-BA nanoplatform serves as a shelter and reservoir for vulnerable immunomodulatory drug BA,which possesses antioxidant,anti-inflammatory and anti-bacterial effects.Thus,MPB-BA can exert its antioxidant,anti-inflammatory functions through scavenging intracellular ROS to switch macrophages from M1 to M2 phenotype so as to relieve inflammation.The underlying molecular mechanism lies in the upregulation of phosphorylated nuclear factor erythroid 2-related factor 2(Nrf2)to scavenge ROS and subsequently inhibit the nuclear factor kappa-B(NF-κB)signal pathway.Moreover,MPB-BA also exhibited efficient photothermal antibacterial activity against periodontal pathogens under near-infrared(NIR)light irradiation.In vivo RNA sequencing results revealed the high involvement of both antioxidant and anti-inflammatory pathways after MPB-BA application.Meanwhile,micro-CT and immunohistochemical staining of p-Nrf2 and p-P65 further confirmed the superior therapeutic effects of MPB-BA than minocycline hydrochloride.This work may provide an insight into the treatment of periodontitis by regulating Nrf2/NF-κB signaling pathway through photothermal bioplatform-assisted immunotherapy.