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Benefiting from the high electrochemical surface area brought by the 2D nanosheet structure, MoS2 has received great research attention for the hydrogen evolution reaction (HER). Recently, it has been demonstrated that by constructing a transitional metal sulfide–MoS2 heterostructure, the HER performance of the MoS2-based catalysts can be further improved. It is even possible to obtain bifunctional catalysts for both HER and oxygen evolution reaction (OER) due to the synergistic effect of the different components in the composite, the electronic effect to enable an efficient electron transfer and appropriate binding energy for the intermediates of the electrocatalytic reactions, and the surface defects on the interface of the heterostructures. Herein, we review the recent progress on the construction of the transitional metal sulfide–MoS2 heterostructure for water splitting based on non-self-supporting and self-supporting catalysts. The surface and interface parameters of the heterostructures are discussed in detail to reveal the key roles of the hybrid structures for energy conversion. We also pay special attention to the theoretical simulations based on first principles to clarify the relationships between the electrochemical performance and structure parameters. Finally, the prospects and challenges of the transition metal sulfide–MoS2 heterostructures for water splitting in the future are proposed to prompt the reasonable design of transition metal sulfide–MoS2 heterostructures for full water splitting. [ABSTRACT FROM AUTHOR]

Single‐atom catalysts (SACs) have attracted increasing research interests owing to their unique electronic structures, quantum size effects and maximum utilization rate of atoms. Metal organic frameworks (MOFs) are good candidates to prepare SACs owing to the atomically dispersed metal nodes in MOFs and abundant N and C species to stabilize the single atoms. In addition, the distance of adjacent metal atoms can be turned by adjusting the size of ligands and adding volatile metal centers to promote the formation of isolated metal atoms. Moreover, the diverse metal centers in MOFs can promote the preparation of dual‐atom catalysts (DACs) to improve the metal loading and optimize the electronic structures of the catalysts. The applications of MOFs derived SACs and DACs for electrocatalysis, including oxygen reduction reaction, oxygen evolution reaction, hydrogen evolution reaction, carbon dioxide reduction reaction and nitrogen reduction reaction are systematically summarized in this Review. The corresponding synthesis strategies, atomic structures and electrocatalytic performances of the catalysts are discussed to provide a deep understanding of MOFs‐based atomic electrocatalysts. The catalytic mechanisms of the catalysts are presented, and the crucial challenges and perspectives are proposed to promote further design and applications of atomic electrocatalysts. [ABSTRACT FROM AUTHOR]

Designing a highly efficient non-precious based oxygen reduction reaction (ORR) electrocatalyst is critical for the commercialization of various sustainable energy storage and conversion devices such as metal-air batteries and fuel cells. Herein, we report a convenient strategy to synthesis Fe3O4 embedded in N doped hollow carbon sphere (NHCS) for ORR. What's interesting is that the carbon microsphere is composed of two-dimensional (2D) nanoplate that could provide more exposed active sites. The usage of solid ZnO nanowires as zinc source is crucial to obtain this structure. The Fe3O4@NHCS-2 exhibits better catalytic activity and durability than the commercial Pt/C catalyst. Moreover, it further displays high-performance of Zn-air batteries as a cathode electrocatalyst with a high-power density of 133 mW·cm−2 and high specific capacity of 701 mA·h·g−1. The special hollow structure composed 2D nanoplate, high surface area, as well as synergistic effect between the high active Fe3O4 nanoparticles and N-doped matrix endows this outstanding catalytic activity. The work presented here can be easily extended to prepare metal compounds decorated carbon nanomaterials with special structure for a broad range of energy storage and conversion devices. [ABSTRACT FROM AUTHOR]

It is of increasing importance to develop highly active and economical oxygen reduction reaction (ORR) electrocatalysts, which have great significance for the large‐scale implementation of various energy conversion systems, including metal–air batteries and fuel cells. Herein, a novel method to synthesize FeNx‐decorated carbon nanotubes as a high‐efficiency ORR catalyst, by utilizing ZnO nanowires as a sacrificial template and a Fe–polydopamine complex as metal and carbon sources, is reported. The obtained catalyst shows great potential for replacing Pt/C as the ORR catalyst under various pH conditions, from alkaline to acidic electrolytes. The high conductivity, large surface area of the carbon nanotube, and highly active FeNx species contributed greatly to the high performance of the catalyst. The work presented herein paves a new way for the synthesis of 1D porous nanomaterials for a broad range of energy‐related applications. Doped to reduce: FeNx‐decorated carbon nanotubes are prepared by utilizing ZnO nanowires as a sacrificial template and Fe–polydopamine (Fe–PDA) complex as metal and carbon sources (see figure). The evaporation of Zn at high temperature results in a high surface area of the carbon nanotubes, and the FeNx species contribute greatly to the oxygen reduction reaction activity of the catalyst. [ABSTRACT FROM AUTHOR]

Boron-containing cobalt (Co–B) nanoparticles (NPs) synthesized by the borohydride reduction process were subjected to ammonization. Part of B species segregate onto particle surfaces to form ultrathin h-BN shells which stabilize highly dispersed Co NPs under harsh conditions and the remaining B atoms interact strongly with Co atoms inside the NPs. The formed CoBx@h-BN core–shell nanocatalysts exhibit an overpotential of 290 mV at a current density of 10 mA cm−2 making them among the most active catalysts for the oxygen evolution reaction (OER) and they present 150 h OER stability. The improved OER performance has been attributed to the synergetic role of the confinement effect of h-BN shells and activation effect of subsurface B atoms. This work suggests a simple synthetic route to prepare highly active and stable metal nanocatalysts without using any surfactants and supports. [ABSTRACT FROM AUTHOR]

CO2 capture via solid adsorption technology relies on the development of low-cost and high-performance new solid adsorbents. The robust and large-scale produced hexagonal boron nitride (h-BN) porous materials are an ideal candidate but present low CO2 adsorption properties. Here, we report that in situ carbon doping of BN materials (BCN) can be facilely controlled by thermal annealing of boric acid and melamine mixtures in various atmospheres. CO2 uptake of the BCN materials is in the range of 3.74–3.91 mmol CO2 g−1 (165–172 mg CO2 g−1) at 298 K and ambient pressure, whereas it is only 1.16–1.66 mmol CO2 g−1 (53.0–73.1 mg CO2 g−1) over the pure BN materials. The separation coefficient between CO2 and N2 is up to 74 and no decrease in the adsorption performance was observed after nine adsorption/desorption cycles. The BCN material presents the best performance among known BN-based sorbents, which is comparable to many excellent carbon materials. Detailed characterization reveals that the incorporation of carbon into the BN matrix increases the density of ultramicropores (＜0.7 nm) and chemical defects, consequently enhancing the CO2 adsorption capacity and the selectivity over N2 molecules. [ABSTRACT FROM AUTHOR]

Benefiting from similar hydrogen bonding energy to Pt and much lower price compare with Pt, Ru based catalysts are promising candidates for electrocatalytic hydrogen evolution reaction (HER). The catalytic activity of Ru nanoparticles can be enhanced through improving their dispersion by using different supports, and the strong metal supports interaction can further regulate their catalytic performance. In addition, single-atom catalysts (SACs) with almost 100% atomic utilization attract great attention and the coordinative atmosphere of single atoms can be adjusted by supports. Moreover, the syngenetic effects of nanoparticles and single atoms can further improve the catalytic performance of Ru based catalysts. In this review, the progress of Ru based HER electrocatalysts are summarized according to their existing forms, including nanoparticles (NPs), single atoms (SAs) and the combination of both NPs and SAs. The common supports such as carbon materials, metal oxides, metal phosphides and metal sulfides are classified to clarify the metal supports interaction and coordinative atmosphere of Ru active centers. Especially, the possible catalytic mechanisms and the reasons for the improved catalytic performance are discussed from both experimental results and theoretical calculations. Finally, some challenges and opportunities are prospected to facilitate the development of Ru based catalysts for HER., (© 2024 Wiley‐VCH GmbH.)

Hepatocellular carcinoma is characterized by a high infiltration of myeloid-derived suppressor cells (MDSC), which are key drivers of maintaining the immunosuppressive tumor microenvironment. Therefore, targeting MDSCs will improve immunotherapies for cancers. It has been shown that all-trans retinoic acid (ATRA) can differentiate MDSCs into mature myeloid cells. However, whether ATRA suppression of MDSCs function could inhibit the growth of liver cancer remains unknown. Here we found that ATRA significantly inhibited hepatocellular carcinoma promotion, tumor cell proliferation, and angiogenesis markers. Moreover, ATRA decreased the number of mononuclear myeloid-derived suppressor cells (M-MDSCs), granulocytic myeloid-derived suppressor cells (G-MDSCs) and tumor-associated macrophages (TAMs) in spleens. In addition, ATRA significantly reduced the intratumoral infiltrating G-MDSCs and the expression of protumor immunosuppressive molecules (arginase 1, iNOS, IDO and S100A8 + A9), which was accompanied by increased cytotoxic T cell infiltration. Our study demonstrates that ATRA not only has direct intrinsic inhibitory effect on tumor angiogenesis and fibrosis, but also reeducates the tumor microenvironment toward an antitumor phenotype by altering the relative proportion between protumor and antitumor immune cells. This information introduces ATRA as a potential druggable target for treatment of hepatocellular carcinoma., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier B.V.)

This study theoretically proved that although reciprocal optical devices can show asymmetric transmittivity (AT) under controlled incident modes (i.e., conditional AT), they cannot guarantee AT with arbitrary incident light modes, whereas only nonreciprocal optical devices can possibly guarantee AT. Besides, the thermodynamics of both reciprocal and nonreciprocal optical devices were discussed to show that the second law of thermodynamics is valid anyway. Furthermore, the diode-like behaviors of optical and electronic devices were compared. Electrons are identical to electronic devices, so electronic devices could have asymmetric conductance regardless of electrons. In contrast, electromagnetic waves are different from optical devices as transmittivity of different modes can be different, so reciprocal optical devices showing conditional AT cannot guarantee AT when incident modes are arbitrary. The mathematical proof and characteristic comparisons between electronic and optical diodes, which are firstly presented here, should help clarifying the necessary nonreciprocity required for being optical diodes., Competing Interests: The authors declare no competing interests., (© 2023 The Author(s).)

Nano bowl-like Co-Co 6 Mo 6 C 2 coated by N,P co-doped carbon (Co-Co 6 Mo 6 C 2 @NPC) is reported as an electrocatalyst for Zn-air batteries. Co-Co 6 Mo 6 C 2 @NPC only needs an overpotential of 210 mV at 10 mA cm -2 for the OER, and the half-wave potential for the ORR is 0.81 V. In addition, the Co-Co 6 Mo 6 C 2 @NPC based battery shows a large open-circuit voltage of 1.335 V and a maximum power density of 160.5 mW cm -2 , as well as good stability. The improved catalytic performance can be ascribed to the co-existence of Co 6 Mo 6 C 2 and Co species to improve the intrinsic catalytic activity, and the bowl-like nanostructure to facilitate the mass transfer.

The tumor immunosuppressive microenvironment plays an important role in tumor progression. Alcohol is well-known as a regulator of the immune system and several studies have also reported that chronic alcohol intake can activate the immune system. However, it is unclear whether alcohol can affect liver cancer progression by regulating the immunosuppressive microenvironment. In this study, we investigated the effects of different alcohol concentrations on the growth of liver cancer and tumor immune microenvironment. We examined the growth of tumors in mice provided with water, or alcohol (for 2 weeks before tumor injection, and for 3 weeks after tumor injection). We found that alcohol consumption at 5% and 20% inhibited the growth of subcutaneous tumors in hepatocellular carcinoma-bearing mice, whereas 2% alcohol concentration did not significantly inhibit liver cancer growth. The ratio of myeloid-derived suppressor cells (MDSCs) in peripheral blood and spleen of mice treated with 5% or 20% alcohol for 2 weeks before tumor inoculation was downregulated. After tumor inoculation, the proportion of MDSCs in peripheral blood, spleen, and tumor of mice treated with 5% or 20% alcohol for another 3 weeks also decreased and the proportion of CD4+ T cells and CD8+ T cells increased. In addition, Alcohol consumption of 20% reduced levels of the inflammatory factor IL-6 by inhibiting JAK/STAT3 signaling. These results indicate that chronic alcohol consumption may inhibit the growth of liver cancer by regulating MDSCs., Competing Interests: None., (AJCR Copyright © 2023.)

Alzheimer's disease (AD) is a progressive and degenerative disorder accompanied by cognitive decline, which could be promoted by mitochondrial dysfunction induced by mitochondrial Ca 2+ (mCa 2+ ) homeostasis Mitochondrial calcium uniporter (MCU), a key channel of mCa 2+ uptake, may be a target for AD treatment. In the present study, we reveal for the first time that MCU knockdown in hippocampal neurons improves the memory performance of APP/PS1/tau mice through radial arm maze task. Western blot analysis, transmission electron microscopy (TEM), Golgi staining, immunohistochemistry (IHC) and ELISA results demonstrate that MCU knockdown in hippocampal neurons upregulates the levels of postsynaptic density protein 95 (PSD95) and synaptophysin (SYP), and increases the numbers of synapses and dendritic spines. Meanwhile, MCU knockdown in hippocampal neurons decreases the neuroinflammatory response induced by astrogliosis and high levels of IL-1β and TNF-α, and improves the PINK1-Parkin mitophagy signaling pathway and increases the level of Beclin-1 but decreases the level of P62. In addition, MCU knockdown in hippocampal neurons recovers the average volume and number of mitochondria. These data confirm that MCU knockdown in hippocampal neurons improves the memory performance of APP/PS1/tau mice through ameliorating the synapse structure and function, relieving the inflammation response and recovering mitophagy, indicating that MCU inhibition has the potential to be developed as a novel therapy for AD.

Objective: To investigate the role and mechanism of the high mobility group box 1 (HMGB1) in intestinal mucosal barrier injury in rat with sepsis induced by endotoxin lipopolysaccharide (LPS)., Methods: The rats were given intraperitoneal injection of LPS to reproduce a model of sepsis. The effect of HMGB1 inhibitor EP solution (40 mg/kg) on sepsis was observed, and phosphate buffer (PBS) control group was set up. Seventy-two hours after modeling, abdominal aortic blood was obtained, and enzyme-linked immunosorbent assay (ELISA) was used to measure the plasma levels of D-lactic acid and diamine oxidase (DAO) of mucosal barrier permeability. The pathological changes of the intestinal mucosal were observed with light microscope and the Chiu score was recorded. The intestinal mucosal ultrastructural changes were observed with electron microscopy. Real-time quantitative reverse transcription-polymerase chain reaction (RT-qPCR) and Western Blot were used to measure the mRNA and protein expressions of Occludin, inflammatory factor HMGB1 and its downstream signal molecule nuclear transcription factor-κB p65 (NF-κB p65) in the rat small intestine., Results: The results of histopathology and ultrastructure of the small intestine showed that in the LPS group, the intestinal mucosa tissue swelled obviously, part of the glands were incomplete, the infiltration of neutrophils increased, themicrovillus cells were absent, arranged indisorder, and the number of tight connections significantly reduced compared with the PBS control group. The levels of D-lactic acid and DAO indicating mucosal barrier permeability, the levels of inflammatory factor HMGB1 and its downstream signaling molecule NF-κB p65 mRNA and protein expressions in the LPS group were significantly higher than those in the PBS control group, and the mRNA and protein expression of Occludin in the small intestine was significantly lower than that in the PBS control group, suggesting that the intestinal mucosal barrier function in septic rats was damaged, permeability increased, and the structure was damaged. After the administration of the HMGB1 inhibitor EP, the intestinal mucosal barrier damage was significantly improved. The performance was as follows: the Chiu score of the small intestine tissue and the plasma D-lactic acid and DAO levels in the EP intervene group were significantly lower than those in the LPS group [Chiu score: 1.60±0.48 vs. 3.40±0.48, D-lactic acid (mmol/L): 3.30±0.22 vs. 5.30±0.16, DAO (U/L): 23.66±0.97 vs. 30.47±1.11, all P < 0.05]. Occludin mRNA and protein expression levels were significantly higher than those in the LPS group [Occludin mRNA (2 -ΔΔCt ): 0.82±0.05 vs. 0.37±0.08, Occludin protein (Occludin/β-actin): 1.04±0.09 vs. 0.75±0.11, both P < 0.05], while the mRNA and protein expression levels of HMGB1 and NF-κB p65 were significantly lower than those in the LPS group [HMGB1 mRNA (2 -ΔΔCt ): 1.63±0.10 vs. 3.57±0.10, HMGB1 protein (HMGB1/β-actin): 1.40±0.07 vs. 1.87±0.07; NF-κB p65 mRNA (2 -ΔΔCt ): 1.47±0.09 vs. 2.62±0.13, NF-ΚB p65 protein (NF-κB p65/β-actin): 1.24±0.14 vs. 1.60±0.13, all P < 0.05]., Conclusions: Intestinal mucosal barrier function of septic rats was damaged, permeability increased, and structure was damaged. The mechanism may be that the expression of inflammatory factor HMGB1 was up-regulated and promoted the activation of its downstream signaling molecule NF-κB, thereby mediated the inflammatory cascade reaction and caused damage to the intestinal mucosa.

It is of increasing importance to develop highly active and economical oxygen reduction reaction (ORR) electrocatalysts, which have great significance for the large-scale implementation of various energy conversion systems, including metal-air batteries and fuel cells. Herein, a novel method to synthesize FeN x -decorated carbon nanotubes as a high-efficiency ORR catalyst, by utilizing ZnO nanowires as a sacrificial template and a Fe-polydopamine complex as metal and carbon sources, is reported. The obtained catalyst shows great potential for replacing Pt/C as the ORR catalyst under various pH conditions, from alkaline to acidic electrolytes. The high conductivity, large surface area of the carbon nanotube, and highly active FeN x species contributed greatly to the high performance of the catalyst. The work presented herein paves a new way for the synthesis of 1D porous nanomaterials for a broad range of energy-related applications., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)