Phase Engineering of Molybdenum Carbide-Cobalt Heterostructures for Long-Lasting Zn-Air Batteries.

Developing highly active and robust oxygen catalysts is of great significance for the commercialization of Zn-air batteries (ZABs) with long-life stability. Herein, heterostructured catalysts comprising molybdenum carbide and metallic Co are prepared by a simple dicyandiamide-assisted pyrolysis strategy. Importantly, the crystalline phase of molybdenum carbide in the catalysts can be carefully regulated by adjusting the CoMo-imidazole precursor and dicyandiamide ratio. The electronic configuration of Co and Mo centers as well as the phase-dependent oxygen reduction reaction performance of these heterostructures (ß-Mo2C/Co, ß-Mo2C/η-MoC/Co, and η-MoC/Co) was disclosed. A highly active η-MoC/Co cathode enables ZABs with outstanding long-term stability over 850 h with a low voltage decaying rate of 0.06 mV·h-1 and high peak power density of 162 mW·cm-2. This work provides a new idea for the rational design of efficient and stable cathode catalysts for ZABs.

Saffron Petal, an Edible Byproduct of Saffron, Alleviates Dextran Sulfate Sodium-Induced Colitis by Inhibiting Macrophage Activation and Regulating Gut Microbiota.

Saffron petal (SP) is an agricultural byproduct in the process of the crude drug saffron, accounting for 90% of the dry weight of saffron flowers. To promote the utilization of SP in the food and pharmaceutical industries, its anti-inflammatory activities were evaluated on LPS-activated RAW 264.7 cells and DSS-challenged colitic mice. The results indicated that the SP extract had a notable effect in alleviating the clinical manifestations of colitis, such as reduction in body weight, improvement in disease activity index, mitigation of colon shortening, and alleviation of colon tissue damage. Moreover, SP extract significantly suppressed macrophage infiltration and activation, evidenced by a decrease in colonic F4/80 macrophages and suppression of the transcription and secretion of colonic tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and interleukin-6 (IL-6) in DSS-challenged colitic mice. In vitro, SP extract also significantly suppressed nitric oxide production, COX-2 and iNOS expressions, and TNF-α and IL-1ß transcription of activated RAW 264.7 cells. Network pharmacology-guided research identified that SP extract significantly downregulated Akt, p38, ERK, and JNK phosphorylation in vivo and in vitro. In parallel, SP extract also effectively corrected microbial dysbiosis by increasing the abundance of Bacteroides acidifaciens, Bacteroides vulgatus, Lactobacillus murinus, and Lactobacillus gasseri. These findings indicate that the effectiveness of SP extract in treating colitis is demonstrated by its ability to reduce macrophage activation, inhibit the PI3K/Akt and MAPK pathways, and regulate gut microbiota, suggesting that SP extract holds great potential as a therapeutic option for colitis.

Tunable Heterogeneous FeCo Alloy-Mo0.82N Bifunctional Electrocatalysts for Temperature-Adapted Zn-Air Batteries.

The practical applications of temperature-tolerant Zn-air batteries (ZABs) rely on highly active and stable bifunctional catalysts that accelerate cathodic oxygen reduction (ORR) and oxygen evolution (OER) reactions. Herein, we successfully integrated fascinating transition metal nitrides and FeCo alloys through a simple coordination assembly and pyrolysis process. Importantly, the alloy-to-nitride ratio in the heterogeneous catalyst can be carefully regulated through the subsequent etching process. Moreover, the composition-dependent ORR/OER performance of the FeCo-Mo0.82N catalysts was revealed. Aqueous ZABs using the optimized FeCo-Mo0.82N-60 as a cathode exhibit a high peak power density of 149.7 mW cm-2 and an impressive stability of 600 h with a low charge-discharge voltage gap decay rate of 0.025 mV h-1, which exceeds those of most of recent reports. Furthermore, the FeCo-Mo0.82N-60-based flexible ZABs display a small specific capacity degradation (3%) from 40 to -10 °C, demonstrating excellent temperature tolerance.

A Potential Role of Plant/Macrofungi/Algae-Derived Non-Starch Polysaccharide in Colitis Curing: Review of Possible Mechanisms of Action.

Multiple in vitro and in vivo model investigations have suggested a broad spectrum of potential mechanisms by which plant/macrofungi-derived non-starch polysaccharides may play a role in the treatment of inflammatory bowel disease (IBD). This article reviews the in vivo and in vitro evidence of different plant-derived polysaccharides for IBD therapy. Their underlying mechanisms, particularly the molecular mechanisms associated with protective effects in the treatment and prevention of IDB, have been well summarized, including anti-inflammatory, epithelial barrier repair, and the regulation of intestinal flora. Emerging studies have observed the potent role of probiotics in IBD, particularly its ability to modulate gut microbiota, a well-known key factor for IBD. In summary, plant/macrofungi-derived polysaccharides have the potential to be a promising agent for the adjuvant treatment and prevention of IBD and will contribute to the design of well-designed clinical intervention trials that will ultimately improve the therapy of IBD.

Fuc-S-A New Ultrasonic Degraded Sulfated α-l-Fucooligosaccharide-Alleviates DSS-Inflicted Colitis through Reshaping Gut Microbiota and Modulating Host-Microbe Tryptophan Metabolism.

SCOPE: The dysbiosis of intestinal microecology plays an important pathogenic role in the development of inflammatory bowel disease. METHODS AND RESULTS: A polysaccharide named Fuc-S, with a molecular weight of 156 kDa, was prepared by the ultrasonic degradation of fucoidan. Monosaccharide composition, FTIR, methylation, and NMR spectral analysis indicated that Fuc-S may have a backbone consisting of →3)-α-L-Fucp-(1→, →4)-α-L-Fucp-(1→ and →3, 4)-α-D-Glcp-(1→. Moreover, male C57BL/6 mice were fed three cycles of 1.8% dextran sulfate sodium (DSS) for 5 days and then water for 7 days to induce colitis. The longitudinal microbiome alterations were evaluated using 16S amplicon sequencing. In vivo assays showed that Fuc-S significantly improved clinical manifestations, colon shortening, colon injury, and colonic inflammatory cell infiltration associated with DSS-induced chronic colitis in mice. Further studies revealed that these beneficial effects were associated with the inhibition of Akt, p-38, ERK, and JNK phosphorylation in the colon tissues, regulating the structure and abundance of the gut microbiota, and modulating the host-microbe tryptophan metabolism of the mice with chronic colitis. CONCLUSION: Our data confirmed the presence of glucose in the backbone of fucoidan and provided useful information that Fuc-S can be applied as an effective functional food and pharmaceutical candidate for IBD treatment.

Unlocking active metal site of Ti-MOF for boosted heterogeneous catalysis via a facile coordinative reconstruction.

Constructing sophisticated hollow structure and exposing more metal sites in metal-organic frameworks (MOFs) can not only enhance their catalytic performance but also endow them with new functions. Herein, we present a facile coordinative reconstruction strategy to transform Ti-MOF polyhedron into nanosheet-assembled hollow structure with a large amount of exposed metal sites. Importantly, the reconstruction process relies on the esterification reaction between the organic solvent, i.e. ethanol and the carboxylic acid ligand, allowing the conversion of MOF without the addition of any other modulators and/or surfactants. Moreover, the surface and internal structure of the reconstructed MOF can be well tuned via altering the conversion time. Impressively, the reconstructed MOF exhibits ∼5.1-fold rate constant compared to the pristine one in an important desulfurization reaction for clean fuels production, i.e. the oxidation of dibenzothiophene.

Non-3d Metal Modulation of a 2D Ni-Co Heterostructure Array as Multifunctional Electrocatalyst for Portable Overall Water Splitting.

Portable water splitting devices driven by rechargeable metal-air batteries or solar cells are promising, however, their scalable usages are still hindered by lack of suitable multifunctional electrocatalysts. Here, a highly efficient multifunctional electrocatalyst is demonstrated, i.e., 2D nanosheet array of Mo-doped NiCo2 O4 /Co5.47 N heterostructure deposited on nickel foam (Mo-NiCo2 O4 /Co5.47 N/NF). The successful doping of non-3d high-valence metal into a heterostructured nanosheet array, which is directly grown on a conductive substrate endows the resultant catalyst with balanced electronic structure, highly exposed active sites, and binder-free electrode architecture. As a result, the Mo-NiCo2 O4 /Co5.47 N/NF exhibits remarkable catalytic activity toward the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), affording high current densities of 50 mA cm-2 at low overpotentials of 310 mV for OER, and 170 mV for HER, respectively. Moreover, a low voltage of 1.56 V is achieved for the Mo-NiCo2 O4 /Co5.47 N/NF-based water splitting cell to reach 10 mA cm-2 . More importantly, a portable overall water splitting device is demonstrated through the integration of a water-splitting cell and two Zn-air batteries (open-circuit voltage of 1.43 V), which are all fabricated based on Mo-NiCo2 O4 /Co5.47 N/NF, demonstrating a low-cost way to generate fuel energy. This work offers an effective strategy to develop high-performance metal-doped heterostructured electrode.