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An ultra-thin (45 ± 5 nm) ion conductive surface protection layer prepared by a simple chemical treatment method effectively enhances the surface stability of Zn electrodes and prolongs their cycling stability.

Heterogeneous molecular catalysts built from β-substituted cobalt porphyrins and carbon nanotubes afford tunable activity for H2O2 synthesis via the two-electron transfer oxygen reduction reaction.

Dynamic changes in the contribution of air pollution, meteorological conditions and aging to cardiovascular mortality.

Fenton processes allow to degrade and mineralize toxic organic contaminants, yet classical Fenton processes require continuously adding hydrogen peroxide and ferrous ions, costly solution pH adjustment, and treatment of secondary iron sludge pollution. Heterogeneous electro-Fenton processes deliver oxidizing radicals with only oxygen and electricity consumed. Bifunctional catalysts allow the synthesis and activation of hydrogen peroxide simultaneously, eliminate additional chemical reagents, and yield no metal residues in treated water. Here, we review bifunctional catalysts for heterogeneous electro-Fenton processes. We describe the mechanisms of oxidizing radical generation from oxygen. Then, we compare different types of bifunctional catalysts based on their elemental compositions: (1) metal/carbon composite catalysts, i.e., monometallic iron/carbon composite catalysts, bimetallic/trimetallic carbon composite catalysts, and transition metal single-atom catalysts; (2) metal composite catalysts without carbon; and (3) metal-free carbon catalysts. Then, we present five other approaches beyond electrocatalysts, which have been used to improve the performance of heterogeneous electro-Fenton processes.

Triptolide (TP) exhibits therapeutic potential against multiple diseases. However, its application in clinics is limited by TP-induced hepatoxicity. TP can activate invariant natural killer T (iNKT) cells in the liver, shifting Th1 cytokine bias to Th2 cytokine bias. The damaging role of iNKT cells in TP-induced hepatoxicity has been established, and iNKT cell deficiency can mitigate hepatotoxicity. However, the activation of iNKT cells in vitro by TP requires the presence of antigen-presenting cells. Therefore, we hypothesized that TP could induce dendritic cells (DCs) to activate iNKT cells, thereby leading to hepatotoxicity. The hepatic conventional DCs (cDCs) exhibited immunogenic activities after TP administration, upregulating the expression of CD1d, co-stimulatory molecules, and IL-12. Neutralization with IL-12p40 antibody extenuated TP-induced hepatotoxicity and reduced iNKT cell activation, suggesting that IL-12 could cause liver injury by activating iNKT cells. TP triggered the activation and upregulation of STING signaling pathway and increased endoplasmic reticulum (ER) stress. Downregulation of STING reduced cDC immunogenicity, inhibiting the activation of iNKT cells and hepatic damage. These indicated the regulatory effects of STING pathway on cDCs and iNKT cells, and the important roles it plays in hepatoxicity. ER stress inhibitor, 4-phenylbutyrate (4-PBA), also suppressed iNKT cell activation and liver injury, which might be regulated by the STING signaling pathway. Our results demonstrated the possible mechanisms underlying TP-induced hepatoxicity, where the activation of cDCs and iNKT cells was stimulated by upregulated STING signaling and increased ER stress as a result of TP administration.

Direct catalytic decomposition of methane (CDM) has been studied as a possible emission-free hydrogen production route for over 100 years. However, the high cost of catalyst regeneration limits its practical applications. Here, we demonstrate that the solid by-product from CDM using Fe ore catalysts comprising carbon nano onions encapsulated with magnetic Fe cores (Fe@C) can serve as efficient and recyclable Fenton catalysts for pollutant degradation. Fe@C/H

Graphene hydrogel fibers are promising electrode materials for emerging wearable energy storage devices. They shrink significantly (up to 10 times in volume) during drying when trapped solvents are removed, accompanied by complex internal structural transformation. This vital drying process has been ignored in previous research. Here, we present a comprehensive study to correlate the drying of graphene hydrogel fibers with their porous structures and electrochemical properties. Five representative drying conditions involving different temperatures, pressures, and solvent exchanging conditions were compared. We found that first, the average interlayer spacing of stacked graphene nanosheets measured by X-ray diffraction is determined during hydrothermal assembly. During drying, the fast solvent removal causes significant pore closure and creates randomly oriented tortuous pores. On the other hand, the evaporation of solvents provides capillary forces to drive the rearrangement of stacked rGO. Trapping non-volatile solvents in hydrogel rGO fibers can preserve interconnected pores, while freeze-drying leads to non-interconnected pores. Subsequently, different dried graphene fibers have dramatically different specific volumetric capacitance ranging from 5 to 120 F cm−3 and diverse rate capability in capacitive energy storage. These new fundamental insights provide useful guides for controllable assembly of 2D materials into fiber architectures for energy storage applications and beyond.

Bulk graphitic carbon materials with expanded interlayer spacing and abundant defects may serve as efficient anodes with high areal capacities for sodium-ion batteries (SIBs). However, obtaining long-range order in bulk graphitic carbon materials with expanded interlayer spacing is extremely difficult. Herein, an explosive decomposition method is demonstrated to realize thermally reduced graphene oxide (rGO) paper with tuned interlayer spacing. The in-situ temperature-dependent X-ray diffraction (td-XRD) was utilized to establish the correlation between heating rate and interlayer spacing. Based on td-XRD results, free-standing graphene paper (FSG) was synthesized at 450°C under a high heating rate of 70°C/min. The FSG exhibits a highly porous structure made of graphene flakes with abundant surface epoxy groups with an overall interlayer spacing of 0.38–0.39 nm. The rGO flakes in FSG are separated by large voids that provide fast mass transport pathways and allow expansion/contraction of crystallites upon reversible Na intercalation. The FSG was utilized directly as anodes without any binder and conductive agent and delivered an excellent reversible capacity of 290 mAh/g at a current density of 50 mA/g. Moreover, the FSG exhibited excellent foldability and rollability to create high areal density anodes, delivering an areal capacity of 0.62 mAh/cm2 at a current density of 100 μA/cm2. These results open the door to fabricate graphene material-based carbon anodes with tunable interlayer spacing for high-performance SIBs.

Extracting lithium electrochemically from seawater has the potential to resolve any future lithium shortage. However, electrochemical extraction only functions efficiently in high lithium concentration solutions. Herein, we discovered that lithium extraction is temperature and concentration dependent. Lithium extraction capacity (i.e., the mass of lithium extracted from the source solutions) and speed (i.e., the lithium extraction rate) in electrochemical extraction can be increased significantly in heated source solutions, especially at low lithium concentrations (e.g., < 3 mM) and high Na+/Li+ molar ratios (e.g., >1000). Comprehensive material characterization and mechanistic analyses revealed that the improved lithium extraction originates from boosted kinetics rather than thermodynamic equilibrium shifts. A higher temperature (i.e., 60 oC) mitigates the activation polarization of lithium intercalation, decreases charge transfer resistances, and improves lithium diffusion. Based on these understandings, we demonstrated that a thermally assisted electrochemical lithium extraction process could achieve rapid (36.8 mg g-1 day-1) and selective (51.79% purity) lithium extraction from simulated seawater with an ultrahigh Na+/Li+ molar ratio of 20,000. The integrated thermally regenerative electrochemical cycle can harvest thermal energy in heated source solutions, enabling a low electrical energy consumption (11.3–16.0 Wh mol-1 lithium). Furthermore, the coupled thermal-driven membrane process in the system can also produce freshwater (13.2 kg m-2 h-1) as a byproduct. Given abundant low-grade thermal energy availability, the thermally assisted electrochemical lithium extraction process has excellent potential to realize mining lithium from seawater. - Australian Research Council under the Future Fellowships scheme - No. FT160100107. - Qatar National Research Fund (QNRF) - No. NPRP12S-0227-1901660.

Background In natural environments, bacteria always live in communities with others where their physiological characteristics are influenced by each other. Bacteria can communicate with one another by using autoinducers. The current knowledge on the effect of quenching bacteria on others is limited to assess the impact of quorum-quenching bacterium Bacillus sp. QSI-1 on proteins pattern and virulence factors production of Aeromonas hydrophila YJ-1. Proteomic analysis was performed to find out protein changes and virulence factors, after 24 h co-culture. Results Results showed that several proteins of A. hydrophila YJ-1 were altered, seventy-two differentially expressed protein spots were excised from 2-DE gels and analyzed by MALDI-TOF/TOF MS, resulting in 63 individual proteins being clearly identified from 70 spots. Among these proteins, 50 were divided into 22 classes and mapped onto 18 biological pathways. Mixed-culture growth with Bacillus sp. QSI-1 resulted in an increase of A. hydrophilia proteins involved in RNA polymerase activity, biosynthesis of secondary metabolites, flagellar assembly, and two-component systems. In contrast, mixed culture resulted in a decreased level of proteins involved in thiamine metabolism; valine, leucine and isoleucine biosynthesis; pantothenate and CoA biosynthesis. In addition, the two extracellular virulence factors, proteases and hemolysin, were significantly reduced when A. hydrophila was co-cultured with QSI-1, while only lipase activity was observed to increase. Conclusions The information gathered from our experiment showed that Bacillus sp. QSI-1 has a major impact on the expression of proteins, including virulence factors of A. hydrophila. Electronic supplementary material The online version of this article (10.1186/s12866-019-1515-6) contains supplementary material, which is available to authorized users.

Transition metal boride (TMB) materials have recently gained vast interest as a new class of catalysts. However, their catalytic performance is still limited due to poor electrical conductivity and limited specific surface area. Here, we demonstrate a generalizable approach to overcome these limitations by anchoring ultrathin nickel boride (NixB) sheets on the surfaces of functionalized small-diameter multi-walled carbon nanotubes (f-MWCNTs). The electrochemically active surface area and charge transfer resistance of the resulting hybrid materials (NixB/f-MWCNT) is 3.4 and 0.24 times that of the NixB nanosheets, respectively. And, NixB/f-MWCNT exhibited superior catalytic activities and stability toward both oxygen evolution and hydrogen evolution reactions. For the overall water splitting, it requires a cell voltage of 1.60 V to reach the current density of 10 mA cm−2, outperforming existing metal boride catalysts as well as commercial IrO2/Pt/C catalysts. Further, X-ray photoelectron spectroscopy revealed the strong chemical coupling between NixB and f-MWCNTs and the in situ formation of highly active NiOOH/NixB and Ni(OH)2/NixB heterojunctions, which contributes to the superior activity. The developed design concept can serve as a general approach to improve other electrocatalysts with low electrical conductivity and specific surface area, such as metal oxides, metal hydroxides, and metal–organic framework-derived materials.

Lithium (Li) production based on the soda evaporation process is time-consuming and unsustainable. The emerging electrochemical Li extraction is time-efficient but requires high-concentration Li sources and significant electrical energy input. Here, we demonstrate a fast, energy-saving, and environment-friendly Li production process by coupling a thermally regenerative electrochemical cycle (TREC) using lithium manganese oxide (LMO) and nickel hexacyanoferrate (NiHCF) electrodes with poly(vinylidene fluoride) membrane-based thermo-osmosis (denoted as TO-TREC). The characterization of LMO and NiHCF electrodes confirmed that the relatively high temperature of TO-TREC has negligible adverse effects on the ion intercalation in LMO and NiHCF electrodes. The LMO/NiHCF pair has a positive temperature coefficient of 0.843 mV K-1. In the TO-TREC process, Li ions are selectively extracted from a Li-containing brine warmed by low-grade heat and then released into a room-temperature recovery solution such as LiCl with a production rate of 50-60 mmol Li+ m-2 h-1. Li source solutions are concentrated by thermo-osmosis simultaneously, making it possible to utilize previously unusable Li-containing sources, such as concentrated brines from desalination plants and industrial effluents. Besides, the TREC harvests thermal energy from the heated brine, saving >20% of electrical energy compared to conventional electrochemical methods. The new process shows the potential to meet the growing global Li demands for many applications. - Qatar National Research Fund (QNRF) - grant #NPRP12S-0227-1901660. - Australian Research Council (ARC) - grant #FT160100107.

Two-dimensional covalent organic frameworks (2D-COFs) are an emerging family of catalytical materials with well-defined molecular structures. The stacking of 2D nanosheets and large intrinsic bandgaps significantly impair their performance. Here, we report coaxial one-dimensional van der Waals heterostructures (1D vdWHs) comprised of a carbon nanotube (CNT) core and a thickness tunable thienothiophene-pyrene COF shell using a solution based in situ wrapping method. Density functional theory calculations and in-operando and ex-situ spectroscopic analysis show that the carbon-sulfur region in the thienothiophene groups is the active catalytic site. The unique coaxial structure enables controllable n-doping from the CNT core to the COF shell depending on COF shell thickness, which lowers the bandgap and work function of COF. Consequently, the charge transfer barrier between the active catalytic site and adsorbed oxygen intermediates becomes lower, resulting in a dramatic enhancement in their catalytic activity for oxygen redox reactions. It enables a high-performance rechargeable zinc-air battery with a specific capacity of 696 mAh gZn-1 under a high current density of 40 mA cm-2 and excellent cycling stability. 1D vdWHs open the door to create multi-dimensional vdWHs for exploring fundamental physics and chemistry, as well as practical applications in electrochemistry, electronics, photonics, and beyond., Comment: 47 pages and 34 figures

Decentralized electrosynthesis of hydrogen peroxide (H2 O2 ) via oxygen reduction reaction (ORR) can enable applications in disinfection control, pulping and textile bleaching, wastewater treatment, and renewable energy storage. Transition metal oxides are usually not efficient catalysts because they are more selective to produce H2 O. Here, it is shown that divalent 3d transition metal cations (Mn, Fe, Co, Ni, and Cu) can control the catalytic activity and selectivity of columbite nanoparticles. They are synthesized using polyoxoniobate (K7 HNb6 O19 ·13H2 O) and divalent metal cations by a hydrothermal method. The optimal NiNb2 O6 holds an H2 O2 selectivity of 96% with the corresponding H2 O2 Faradaic efficiency of 92% in a wide potential window from 0.2 to 0.6 V in alkaline electrolyte, superior to other transition metal oxide catalysts. Ex situ X-ray photoelectron and operando Fourier-transformed infrared spectroscopic studies, together with density functional theory calculations, reveal that 3d transition metals shift the d-band center of catalytically active surface Nb atoms and change their interactions with ORR intermediates. In an application demonstration, NiNb2 O6 delivers H2 O2 productivity up to 1 molH2O2 gcat -1 h-1 in an H-shaped electrolyzer and can yield catholytes containing 300 × 10-3 m H2 O2 to efficiently decomposing several organic dyes. The low-cost 3d transition-metal-mediated columbite catalysts show excellent application potentials.

Metal-nitrogen-carbon (M-N-C) single-atom catalysts (SACs) show high catalytic activity for many important chemical reactions. However, an understanding of their intrinsic catalytic activity remains ambiguous because of the lack of well-defined atomic structure control in current M-N-C SACs. Here, we use covalent organic framework SACs with an identical metal coordination environment as model catalysts to elucidate the intrinsic catalytic activity of various metal centers in M-N-C SACs. A pH-universal activity trend is discovered among six 3d transition metals for hydrogen peroxide (H2O2) synthesis, with Co having the highest catalytic activity. Using density functional calculations to access a total of 18 metal species, we demonstrate that the difference in the binding energy of O2* and HOOH* intermediates (EO2*- EHOOH*) on single metal centers is a reliable thermodynamic descriptor to predict the catalytic activity of the metal centers. The predicted high activity of Ir centers from the descriptor is further validated experimentally. This work suggests a class of structurally defined model catalysts and clear mechanistic principles for metal centers of M-N-C SACs in H2O2 synthesis, which may be further extendable to other reactions.

Cholestasis is one of the most common clinical symptom of liver diseases. If patients do not receive effective treatment, cholestasis can evolve into liver fibrosis, cirrhosis and ultimately liver failure requiring liver transplantation. Currently, only ursodeoxycholic acid, obeticholic acid and bezafibrate are FDA-approved drugs, thereby requiring a breakthrough in new mechanisms and therapeutic development. Inflammation is one of the common complications of cholestasis. Hepatic accumulation of toxic hydrophobic bile acids is a highly immunogenic process involving both resident and immigrating immune cells. And the resulting inflammation may further aggravate hepatocyte injury. Though, great investigations have been made in the immune responses during cholestasis, the relationship between immune responses and cholestasis remains unclear. Moreover, scarce reviews summarize the immune responses during cholestasis and the efficacy of therapies on immune response. The main purpose of this paper is to review the existing literature on dysfunctional immune response during cholestasis and the effect of treatment on immune response which may provide an insight for researchers and drug development.

Covalent organic frameworks (COFs) with redox-active moieties are potential capacitive energy storage materials. However, their performance is limited by their poor electrical conductivity and sluggish ion diffusion in their nanopores. Herein, we report coaxial one-dimensional van der Waals heterostructures (vdWHs) comprised of a carbon nanotube (CNT) core and a pyrene–pyridine COF shell synthesized by an in situ wrapping method. The coaxial structure allows efficient electronic interaction between the CNT core and COF shell and improves the electrical conductivity significantly. It also improves electrolyte ion accesses to redox-active pyridine groups in the COF, resulting in excellent capacitive energy storage performance with a high specific capacitance of ∼360 F g−1, an excellent rate capability of ∼80%, and a good stability of 92% capacitance retention after 20 000 charge/discharge cycles. Our strategy opens the door to create other multi-dimensional vdWHs for various potential applications.

Rechargeable zinc-air batteries (R-ZABs) are attractive for many essential energy storage applications – from portable electronics, electric vehicles to incorporation of renewable energy due to their high energy storage density, abundant raw materials, and inherent safety. However, alkaline electrolytes cause critical obstacles in realizing a long battery life. Thus, neutral electrolytes are attracting growing interest. However, the current understandings of R-ZABs in neutral/near-neutral electrolytes are far behind those in alkaline electrolytes. This review summarizes the latest research progress of neutral electrolytes used in R-ZABs, including aqueous inorganic and organic salt solutions, water-in-salt electrolytes, and quasi-solid electrolytes based on polymer hydrogels. Research efforts in improving the stability of Zn anodes in neutral electrolytes are also reviewed. Reaction mechanisms of oxygen reduction and evolution reactions in alkaline and neutral electrolytes are compared in the context of R-ZABs, together with a summary of potential oxygen electrocatalysts applicable in neutral conditions. Different device configurations are introduced. We further provide our perspectives on future research directions of R-ZABs with neutral electrolytes.

Aqueous sodium-ion batteries (A-SIBs) are a cost-effective and safe battery candidate for stationary energy storage systems. Prussian blue and its analogues (PBAs) have been studied as cathode materials in A-SIBs. However, few studies have used PBAs as anode materials because of their small specific capacity and low cell voltages. Herein, we report that chromium hexacycnochromate (CrCr PBA) can serve as an efficient anode material to enable high-performance A-SIBs. CrCr PBA contains Cr ions at two types of sites coordinated by C and N, offering two redox pairs at −0.62/−0.65 V and −0.73/−0.77 V (vs. Ag/AgCl electrode), respectively. X-ray photoelectron and electron energy loss spectroscopic characterizations of CrCr PBA at different charge/discharge stages show that Cr at both types of coordinated sites can efficiently participate in Na+ storage, delivering a high specific capacity of 108.2 mAh g−1 at a discharge rate of 0.5 A g−1. Besides, low redox potentials of CrCr PBA also contribute to a higher battery voltage. Coupled with a manganese hexacyanoferrate cathode in a water-in-salt electrolyte (17 M NaClO4), full coin cells exhibit a high energy density of 81.6 Wh kg−1 and a high capacity of 52.8 mAh g−1 at an average voltage of 1.55 V. They also display a long-cycle-life with 93.01% capacity retention over 500 cycles at 30C with around 100% Coulombic efficiency. Their performance is one of the best among recently reported A-SIBs. Because of their similar energy storage mechanisms, CrCr PBA may also serve as promising anode materials in other types of aqueous alkaline metal-ion batteries (e.g., lithium-ion battery and potassium-ion battery).

Table S1. Functional classes and unclassified proteins of A. hydrophila YJ-1 that were differentially expressed when co-cultured with Bacillus sp. QSI-1. (DOCX 31 kb)

Table S2. Primer sequences for qPCR in this study. (DOC 46 kb)

Proinflammatory cytokines are potent inhibitors of bile acid nuclear receptors and transporters. Triptolide (TP), an active ingredient of Tripterygium wilfordii Hook. f., exhibits unique efficacy for autoimmune diseases and tumors. While its clinical application is greatly constrained by hepatotoxicity. Therefore, we explored the mechanism of iNKT cells and associated immunoregulators in TP-induced cholestatic liver injury. TP was administered to both female C57BL/6 mice and Jα18-/- mice. INKT cells released significantly increased Th2 cytokine IL-4 in C57BL/6 mice after TP administration. Blood biochemistry, histopathology and immunohistochemistry demonstrated that TP-induced cholestasis liver injury. In Jα18-/- mice, cholestatic liver damage was alleviated due to the upregulation of type 2 NKT cells, nuclear receptor FXR, transporter OATP1B2 and CYP450, but also the downregulation of Cxcl10, ICAM-1 and Egr-1. Above results suggested that Th2 cytokines produced by iNKT cells suppressed type 2 NKT cells and promoted the expression of immunoregulatory factors represented by CXCL10, ICAM-1 and Egr-1, which in turn affected cholestasis-related nuclear receptor, transporter and enzymes, thus aggravated cholestatic liver injury. Our research contributes to better understanding of the role of iNKT cells in TP-induced cholestatic liver injury, thereby providing potential therapeutic targets for clinical prevention and treatment.

Big Data is the resource for people to obtain new cogitation and create initiative and also a method to change business markets, organizations or institutions and the relationship between the government and citizens. In the Big Data era, the data bank has a great impact on the inter- disciplinary English majors' English writing teaching mode. This paper discusses the opportunities and challenges of the inter-disciplinary English majors' English writing teaching mode, emphasizing that the humanistic education should be covered in the process of English writing process. The teachers utilize the data information technology to develop modern course courser in order to improve students' writing on the whole and foster humanistic qualities. The research elucidates the advantages of the linguistic materials from the Big Data and further differentiates the possible lack of humanistic education relying on the vast Big Data. The revolution of teachers' role switches from lecturer to guider, from instructor to supporter, from grader to referee.