Ordered porous Mn - Co spinel oxide (CoMn2O4) with vacancies modulation as efficient electrocatalyst for Li - O2 battery.

Nonaqueous Li - O2 battery (LOB) is considered one of the most promising energy storage system due to its ultrahigh theoretical specific capacity (3500 Wh kg-1). Introducing vacancies in CoMn2O4 catalysts is regarded as an effective strategy to enhance the electrochemical performances of LOB. However, the relation between vacancy types in CoMn2O4 and catalytic performances in the LOB remains ambiguous. Herein, ordered porous CoMn2O4 with oxygen and metal vacancies is obtained via solvothermal reaction followed by temperature-controlled calcination using polystyrene spheres as templates. The increase in treatment temperature reduces the content of oxygen vacancies while increasing that of the metal vacancies. Notably, experimental results and theoretical calculations show that oxygen vacancies in CoMn2O4 have a greater influence than metal vacancies in modulating the LiO2 adsorption during the reaction processes and reducing the overpotential. CoMn2O4 synthesized at 500 ℃ (CoMnO-500) with higher oxygen vacancies exhibits stronger adsorption onto the LiO2, facilitating the formation of film-like Li2O2. Therefore, an LOB with the CoMnO-500 catalyst presents the lowest overpotential of 1.2 V and longest cycle lifespan of 286 cycles at a current density of 200 mA g-1. This study offers insights into the effect of CoMn2O4 vacancies on the formation pathway of Li2O2 discharge products.

Associations of fruit, whole grain, and total energy intakes with gut microbiome diversity and composition.

Background: The relationship between fruit, whole grain, and total energy consumption and the gut microbiome in the Chinese population remains unclear. Objective: We investigated the relationship between intakes of fruits, whole grains, and energy, and the diversity and composition of gut microbiota. Design: This cross-sectional study included 167 subjects aged 40-75 years who underwent colonoscopy at Nankai Hospital in Tianjin, China. Each of the participants completed a personal history questionnaire, a 7-day dietary record, and donated a fecal sample. The V3-V4 hypervariable region of the bacterial 16S rRNAgene was amplified and sequenced using Illumina Novaseq. The relationship between diet and gut microbiota was evaluated in terms of both the overall composition and the abundance of specific taxon. Results: Fruits intake was positively related to the abundance of Bacilli, Porphyromonadaceae, Streptococcaceae, Parabacteroides, Streptococcus, and Bilophila in fecal samples. Higher whole grains intake was associated with higher microbial diversity, as measured by Shannon, Simpson, and Chao1 indices. Specifically, there was a significant increase inthe relative abundance of Lachnospiraceae and a decrease in Actinobacteria with increased whole grains intake. Moreover, higher intake of total energy was associated with a lower abundance of Anaerostipes and a higher abundance of Lactobacillales and Acidaminococcus. Conclusion: Whole grains intake was positively associated with gut microbial diversity. Fruits and total energy intake were related to the abundance of specifictaxon (e.g., Bacilli and Acidaminococcus). These findings highlight the potential importance of dietary interventions for modulating gut microbiota composition and promoting overall health.

Synergistic wound repair effects of a composite hydrogel for delivering tumor-derived vesicles and S-nitrosoglutathione.

Treating chronic wounds requires transition from proinflammatory M1 to anti-inflammatory M2 dominant macrophages. Based on the role of tumor extracellular vesicles (tEVs) in regulating the phenotypic switching from M1 to M2 macrophages, we propose that tEVs may have a beneficial impact on alleviating the overactive inflammatory microenvironment associated with refractory wounds. On the other hand, as a nitric oxide donor, S-nitrosoglutathione (GSNO) can regulate inflammation, promote angiogenesis, enhance matrix deposition, and facilitate wound healing. In this study, a guar gum-based hydrogel with tEVs and GSNO was designed for the treatment of diabetic refractory wounds. This hybrid hydrogel was formed through the phenyl borate bonds, which can automatically disintegrate in response to the high reactive oxygen species (ROS) level at the site of refractory diabetic wounds, releasing tEVs and GSNO. We conducted a comprehensive evaluation of this hydrogel in vitro, which demonstrated excellent performance. Meanwhile, using a full-thickness excision model in diabetic mice, the wounds exposed to the therapeutic hydrogel healed completely within 21 days. The increased closure rate was associated with macrophage polarization and collagen deposition, accelerated fibroblast proliferation, and increased angiogenesis in the regenerating tissues. Therefore, this multifunctional hybrid hydrogel appears to be promising for clinical applications.

Facile One-Step Heat Treatment of Cu Foil for Stable Anode-Free Li Metal Batteries.

The anode-free lithium metal battery (AFLMB) is attractive for its ultimate high energy density. However, the poor cycling lifespan caused by the unstable anode interphase and the continuous Li consumption severely limits its practical application. Here, facile one-step heat treatment of the Cu foil current collectors before the cell assembly is proposed to improve the anode interphase during the cycling. After heat treatment of the Cu foil, homogeneous Li deposition is achieved during cycling because of the smoother surface morphology and enhanced lithiophilicity of the heat-treated Cu foil. In addition, Li2O-riched SEI is obtained after the Li deposition due to the generated Cu2O on the heat-treated Cu foil. The stable anode SEI can be successfully established and the Li consumption can be slowed down. Therefore, the cycling stability of the heat-treated Cu foil electrode is greatly improved in the Li|Cu half-cell and the symmetric cell. Moreover, the corresponding LFP|Cu anode-free full cell shows a much-improved capacity retention of 62% after 100 cycles, compared to that of 43% in the cell with the commercial Cu foil. This kind of facile but effective modification of current collectors can be directly applied in the anode-free batteries, which are assembled without Li pre-deposition on the anode.

Functional carbon nanodots improve soil quality and tomato tolerance in saline-alkali soils.

High salinity and alkalinity of saline-alkali soil lead to soil deterioration, the subsequent osmotic stress and ion toxicity inhibited crops growth and productivity. In this research, 8 mg kg-1 and 16 mg kg-1 functional carbon nanodots (FCNs) can alleviate the adverse effects of saline-alkali on tomato plant at both seedling and harvest stages, thanks to their up-regulation effects on soil properties and plant physiological processes. On one hand, FCNs stimulate the plant potential of tolerance to saline-alkali and disease resistance through triggering the defense response of antioxidant system, enhancing the osmotic adjustment, promoting the nutrient uptake, transportation and utilization, and up-regulating the photosynthesis, thereby improve tomato growth and productivity in saline-alkali soils. On the other hand, FCNs application contributes to the improvement of soil physicochemical properties and fertilities, as well as decline soil salinity and alkalinity, which are related to plant growth and fruit quality. This research also focuses on the dose-dependent effects of FCNs on their regulation effects and toxicity to tomato growth under stress or non-stress. These findings recommend that FCNs could be applied as potential amendments to ameliorate the saline-alkali soil and improve the tomato tolerance and productivity in the Yellow River Delta.

Structural Engineering of SnS2 Encapsulated in Carbon Nanoboxes for High-Performance Sodium/Potassium-Ion Batteries Anodes.

Conversion-alloying type anode materials like metal sulfides draw great attention due to their considerable theoretical capacity for sodium-ion batteries (SIBs) and potassium-ion batteries (PIBs). However, poor conductivity, severe volume change, and harmful aggregation of the material during charge/discharge lead to unsatisfying electrochemical performance. Herein, a facile and green strategy for yolk-shell structure based on the principle of metal evaporation is proposed. SnS2 nanoparticle is encapsulated in nitrogen-doped hollow carbon nanobox (SnS2 @C). The carbon nanoboxes accommodate the volume change and aggregation of SnS2 during cycling, and form 3D continuous conductive carbon matrix by close contact. The well-designed structure benefits greatly in conductivity and structural stability of the material. As expected, SnS2 @C exhibits considerable capacity, superior cycling stability, and excellent rate capability in both SIBs and PIBs. Additionally, in situ Raman technology is unprecedentedly conducted to investigate the phase evolution of polysulfides. This work provides an avenue for facilely constructing stable and high-capacity metal dichalcogenide based anodes materials with optimized structure engineering. The proposed in-depth electrochemical measurements coupled with in situ and ex situ characterizations will provide fundamental understandings for the storage mechanism of metal dichalcogenides.

Bafilomycin A1 Accelerates Chronic Refractory Wound Healing in db/db Mice.

Numerous studies have reported that autophagy plays an important role in chronic wound healing, and enhancement of autophagic activity impairs cutaneous wound healing. The autophagy inhibitor Bafilomycin A1 (Baf A1) inhibits autophagy by preventing the formation of autophagosomes. This study aimed at elucidating the effect of Bafilomycin A1 on chronic refractory wound healing in diabetic mice. A total of 40 diabetic (db/db) mice and 20 nondiabetic (db/m) mice were used in this study. Full-thickness skin defects were generated in the db/db mice models, which were then divided into the following two groups: the nontreated (db/db group) and Baf A1-treated groups (Baf A1 group). The same skin defects were generated in db/m mice (db/m group) to serve as a control. We demonstrated that Baf A1 treatment significantly accelerated wound healing in db/db mice and exerted good healing effects. Moreover, Baf A1 inhibited autophagy in the newly generated epidermis and had minor effects on metabolism in db/db mice. PCNA expression, as detected by immunohistochemistry, and collagen thickness, as detected by Masson's trichrome staining on the 14th day, were higher in the db/m and Baf A1 groups than in the db/db group. In addition, the expression of the proinflammatory cytokine TNF-α in the db/m and Baf A1 groups increased significantly on day 6, and the expression of the anti-inflammatory cytokine IL-10 also increased significantly on day 9. However, there were no significant changes in the expression levels of TNF-α and IL-10 in the db/db group. Therefore, Baf A1 may accelerate diabetic chronic refractory wound healing by promoting cell proliferation, collagen production, and regulating the inflammatory balance.

Stable Lithium Anode of Li-O2 Batteries in a Wet Electrolyte Enabled by a High-Current Treatment.

Rechargeable Li-air (O2) batteries have attracted a great deal of attention because of their high theoretical energy density and been regarded as a promising next-generation energy storage technology. Among numerous obstacles to Li-air (O2) batteries preventing their use in practical applications, water is a representative impurity for Li-air (O2), which could hasten the deterioration of the anode and accelarate the premature death of cells. Here, we report an effective in situ high-current pretreatment process to enhance the cycling performance of Li-O2 batteries in a wet tetraethylene glycol dimethyl ether-based electrolyte. With the help of certain levels of H2O (from 100 to 2000 ppm) in the electrolyte, adequate Li2O formed on the lithium anode surface after high-current pretreatment, which is necessary for a robust and uniform solid electrolyte interphase layer to protect Li metal during the long-term discharge-charge cycling process. This in situ high-current pretreatment method in a wet electrolyte is shown to be an effective approach for enhancing the cycling performance of Li-O2 batteries with a stable Li metal anode and promoting the realization of practical Li-air batteries.