Cyp2e1 protects against OVA-induced allergic rhinitis through the inhibition of Th2 cell activation and differentiation: Mediated by MAFB.

Allergic rhinitis (AR) is a common allergic disease. Cytochrome P450, family 2, subfamily e, polypeptide 1 (Cyp2e1) is a member of the cytochrome P450 family of enzymes, while its role in AR is still unveiled. In AR mice, T cell-specific overexpression of Cyp2e1 relieved the AR symptoms. Overexpressed-Cyp2e1 restrained the infiltration of eosinophils and mast cells in the nasal mucosa of mice, and the inflammatory cells in nasal lavage fluid (NALF). Cyp2e1 overexpressed mice exhibited decreased goblet cell hyperplasia and mucus secretion as well as decreased MUC5AC expression in nasal mucosa. The epithelial permeability and integrity of nasal mucosa were improved upon Cyp2e1 overexpression in AR mice, as evidenced by decreased fluorescein isothiocyanate-dextran 4 content in serum, increased expression of IL-25, IL-33, and TSLP in NALF, and increased expression of ZO-1 and occluding in nasal mucosa. Cyp2e1 inhibited Th2 immune response by decreasing the expression and secretion of IL-4, IL-5, and IL-13 as well as the expression of GATA-3 in NALF or nasal mucosa. We proved that Cyp2e1 inhibited the differentiation of naïve CD4+ T cells toward the Th2 subtype, which was regulated by MAFB by binding to Cyp2e1 promoter to activate its transcription. Overall, these results show the potential role of Cyp2e1 in alleviating AR symptoms by restraining CD4+ T cells to Th2 cell differentiation. Our findings provide further insight into the AR mechanism.

Mixed-valence molybdenum oxide as a recyclable sorbent for silver removal and recovery from wastewater.

Silver ions in wastewater streams are a major pollutant and a threat to human health. Given the increasing demand and relative scarcity of silver, these streams could be a lucrative source to extract metallic silver. Wastewater is a complex mixture of many different metal salts, and developing recyclable sorbents with high specificity towards silver ions remains a major challenge. Here we report that molybdenum oxide (MoOx) adsorbent with mixed-valence (Mo(V) and Mo(VI)) demonstrates high selectivity (distribution coefficient of 6437.40 mL g-1) for Ag+ and an uptake capacity of 2605.91 mg g-1. Our experimental results and density functional theory calculations illustrate the mechanism behind Ag+ adsorption and reduction. Our results show that Mo(V) species reduce Ag+ to metallic Ag, which decreases the energy barrier for subsequent Ag+ reductions, accounting for the high uptake of Ag+ from wastewater. Due to its high selectivity, MoOx favorably adsorbs Ag+ even in the presence of interfering ions. High selective recovery of Ag+ from wastewater (recovery efficiency = 97.9%) further supports the practical applications of the sorbent. Finally, MoOx can be recycled following silver recovery while maintaining a recovery efficiency of 97.1% after five cycles. The method is expected to provide a viable strategy to recover silver from wastewater.

Effects of different substrates on the adsorption behavior of supported-adsorbents: A case study of MoS2 for Ag+ adsorption.

Supported-adsorbents growing on the substrate in situ are equipped with the advantages of high adsorption capacity, excellent regeneration performance, and adaptability to complex wastewater. However, the effects of substrate on the adsorption properties of supported-adsorbent are rarely considered, which will hinder its development and scale-up applications. In this study, the influences of different substrates (Ti, Mo, W, CC) on the Ag+ adsorption behavior of supported-MoS2 adsorbents were investigated. The adsorption kinetics, adsorption mechanism, and the renewability of these supported-MoS2 were compared orderly. As a result, MoS2 grown on a tungsten substrate (MoS2-W) exhibits a remarkable adsorption capacity for Ag+ (1.98 mg cm-2 and 598.80 mg g-1), which is 6.38-33 times more than the other three supported-MoS2. Moreover, the MoS2-W also possesses an ultrahigh distribution coefficient (24.80 mL cm-2) for Ag+, and the selection coefficient can reach 1984. XRD and electrochemical characterization analysis indicated that Ag+ adsorption performance of supported-MoS2 is positively correlated with the degree of its amorphous structure. Substrate W with the terrific electrical properties which may facilitate the disordered growth of MoS2, resulting in more active sites exposed, and endow MoS2-W with outstanding Ag+ capture performance. Finally, the supported-MoS2 retains a high removal efficiency of Ag+ after 5 cycles of adsorption and desorption. This study provides a novel perspective for promoting the practical application of supported-sorbents to recycle heavy metals.

Proton Self-Enhanced Hydroxyl-Enriched Cerium Oxide for Effective Arsenic Extraction from Strongly Acidic Wastewater.

Acid recycling and arsenic recovery from strongly acidic wastewater are goals of the metallurgical industry to reduce carbon emissions. In this study, arsenic was recovered using a hydroxyl-enriched CeO2 adsorbent, and the adsorption mechanism in a strongly acidic solution was investigated. The adsorption capacities of 88.59 mg/g for As(III) and 126.211 mg/g for As(V) at pH 1.0 are the highest reported values to date. It is revealed that the hydroxyl groups on the CeO2 surface can buffer hydrogen ions, and the isoelectric point of the material can be reduced to pH 1.52. The binding energy of arsenic is -1.25 eV for the hydroxyl-enriched CeO2 and -2.24 eV for CeO2 without hydroxyl groups. Additionally, the protonated hydroxyl groups reduce the oxidation energy of As(III) and promote the adsorption of arsenic by forming new active sites in the strongly acidic solution. Nearly 98.11% of arsenic (initial concentration is 886.8 mg/L) is removed within 24 h without pH adjustment, indicating the feasibility of hydroxyl-enriched CeO2 for recovering arsenic and acid. This work investigated the adsorption and proton-enhanced oxidation mechanism of arsenic by hydroxyl-enriched CeO2 in strongly acidic wastewater.

Electrochemical recovery and high value-added reutilization of heavy metal ions from wastewater: Recent advances and future trends.

Wastewater treatment for heavy metals is currently transitioning from pollution remediation towards resource recovery. As a controllable and environment-friendly method, electrochemical technologies have recently gained significant attention. However, there is a lack of systematic and goal oriented summarize of electrochemical metal recovery techniques, which has inhibited the optimized application of these methods. This review aims at recent advances in electrochemical metal recovery techniques, by comparing different electrochemical recovery methods, attempts to target recycling heavy metal resources with minimize energy consumption, boost recovery efficiency and realize the commercial application. In this review, different electrochemical recovery methods (including E-adsorption recovery, E-oxidation recovery, E-reduction recovery, and E-precipitation recovery) for recovering heavy metals are introduced, followed an analysis of their corresponding mechanisms, influencing factors, and recovery efficiencies. In addition, the mass transfer efficiency can be promoted further through optimizing electrodes and reactors, and multiple technologies (photo-electrochemical and sono-electrochemical) could to be used synergistically improve recovery efficiencies. Finally, the most promising directions for electrochemical recovery of heavy metals are discussed along with the challenges and future opportunities of electrochemical technology in recycling heavy metals from wastewater.

Bacteria-affinity aminated carbon nanotubes bridging reduced graphene oxide for highly efficient microbial electrocatalysis.

Bioelectrochemical systems (BESs) exhibit great potential for simultaneous wastewater treatment and energy recovery. However, the efficiency of microbial electrocatalysis is fundamentally limited by the high resistance and poor biocompatibility of electrode materials. Herein, we construct a novel "binder-free" 3D biocompatible bioelectrode consists of 1D aminated carbon nanotubes (CNTs-NH2) and 2D conductive reduced graphene oxide (rGO) nanosheets through one-step electrodeposition. As expected, the maximum current density reached to 3.25 ± 0.03 mA cm-2 with the rGO@CNTs-NH2 electrode, which is 4.33-fold higher than that of a bare rGO (0.75 ± 0.01 mA cm-2), and is among the best performance reported for three-dimensional electrodes. The high microbial electrocatalytic activity is mainly attributed to the excellent performance of electron transfer and bacterial colonization, which originates from the 3D interconnecting scaffold, fast 1D CNTs "e-bridge" and positively charged surface.