Confined growth of Ultrathin, nanometer-sized FeOOH/CoP heterojunction nanosheet arrays as efficient self-supported electrode for oxygen evolution reaction.

Self-supported electrodes, featuring abundant active species and rapid mass transfer, are promising for practical applications in water electrolysis. However, constructing efficient self-supported electrodes with a strong affinity between the catalytic components and the substrate is of great challenge. In this study, by combining the ideas of in-situ construction and space-confined growth, we designed a novel self-supported FeOOH/cobalt phosphide (CoP) heterojunctions grown on a carefully modified commercial Ni foam (NF) with three-dimensional (3D) hierarchically porous Ni skeleton (FeOOH/CoP/3D NF). The specific porous structure of 3D NF directs the confined growth of FeOOH/CoP catalyst into ultra-thin and small-sized nanosheet arrays with abundant edge active sites. The active FeOOH/CoP component is stably anchored on the rough pore wall of 3D NF support, leading to superior stability and improved conductivity. These structural advantages contributed to a highly facilitated oxygen evolution reaction (OER) activity and enhanced durability of the FeOOH/CoP/3D NF electrode. Herein, the FeOOH/CoP/3D NF electrode afforded a low overpotential of 234 mV at 10 mA cm-2 (41 mV smaller than FeOOH/CoP grown on unmodified Ni foam) and high stability for over 90 h, which is among the top reported OER catalysts. Our study provides an effective idea and technique for the construction of active and robust self-supported electrodes for water electrolysis.

Gastric acid-responsive deformable sodium alginate/Bletilla striata polysaccharide in situ gel for the protection and treatment of alcohol-induced peptic ulcers.

First-line drugs for peptic ulcer (PU) treatment are typically limited by poor targeting and adverse effects associated with long-term use. Despite recent advancements in novel therapeutic approaches for PU, the development of sustained-release delivery systems tailored to specific pathological characteristics remains challenging. Persistent inflammation, particularly gastric inflammatory microenvironment imbalance, characterizes the PU. In this study, we prepared an in situ gel composed of sodium alginate, deacetylated gellan gum, calcium citrate, and Bletilla striata polysaccharide (BSP) to achieve sustained release of BSP. The BSP in situ gel demonstrated favorable fluidity in vitro and completed self-assembly in vivo in response to the acidic milieu at a pH of 1.5. Furthermore, the shear, extrusion, and deformation properties increased by 26.4 %, 103.7 %, and 46.3 %, respectively, with long-term gastric retention (4 h) and mucosal adaptation. Animal experiments confirmed that the BSP in situ gel could attenuate necrotic injury and inflammatory cell infiltration, maintain mucosal barrier integrity, regulate cytokine imbalance and inflammation-associated hyperapoptosis, thus effectively alleviate the inflammatory microenvironmental imbalance in PU without significant side effects. Overall, our findings demonstrated that the BSP in situ gel is a promising therapeutic strategy for PU and opens avenues for developing self-assembled formulations targeting the pathological features of PUs.

Atractylodes Processing Products Protect against Gastric Ulcers in Rats by Influencing the NF-κB-MMP-9/TIMP-1 Regulatory Mechanism and Intestinal Flora.

Atractylodes macrocephala Koidz. (AM) is a Chinese herbal medicine that is widely used for treating gastrointestinal diseases. However, little research has focused on it as a single medicine for treating gastric ulcers. Honey-bran stir-frying is a characteristic method of concocting AM, so we speculated that AM is more effective after this preparation process. Analysis by ultra-high-performance liquid chromatography-hybrid quadrupole-Orbitrap high-resolution mass spectrometry revealed changes in the chemical composition of raw Atractylodes (SG), bran-fried Atractylodes (FG), and honey-bran-fried Atractylodes (MFG). MFG was superior to SG and FG in improving the pathological structure of gastric tissue in rats with acute gastric ulcers, reducing inflammatory cell infiltration in gastric tissue, and significantly reducing malondialdehyde while increasing superoxide dismutase and glutathione peroxidase, and reducing the damage caused by free radical accumulation in the gastric mucosa. In addition, MFG reduced the expression of matrix metalloproteinase-9 (MMP-9), an inhibitor of metalloproteinase-1 (TIMP-1) and nuclear factor kappa-B (NF-κB)proteins, inhibited inflammatory response, and regulated the degradation and rebalancing of the extracellular matrix. Fecal microbiota analysis also revealed that MFG normalized the intestinal flora to some extent. Our study shows that AM had a protective effect on rats with alcohol-induced acute gastric ulcers before and after processing, and AM-processed products were more effective than raw ones. Compared with MF, MFG had a higher rate of ulcer inhibition and a stronger anti-inflammatory effect, and its mechanism of action was related to the NF-κB-MMP-9/TIMP-1 signaling pathway.

Digestion-Promoting Effects and Mechanisms of Dashanzha Pill Based on Raw and Charred Crataegi Fructus.

Emerging evidence suggests that a high-fat diet (HFD) can influence endoplasmic reticulum (ER) stress and gut microbiota. Crataegi Fructus is a traditional Chinese herb widely used in formulas for dyspepsia, with Dashanzha Pill composed of raw Crataegi Fructus (DR) being a representative drug. Processing products of Crataegi Fructus, however, have a stronger pro-digestive effect, and we hypothesized that Dashanzha Pill composed of charred Crataegi Fructus (DC) is more effective. We found that the contents of glucose 1-phosphate and luteolin in DR and DC were substantially different via ultra-high performance liquid chromatography-hybrid quadrupole-Orbitrap high-resolution mass spectrometry. DC outperformed DR in improving histopathological changes, increasing gastrin and motilin, and decreasing vasoactive intestinal peptides in rats with HFD induced dyspepsia. Fecal microbiota analysis revealed that DC could restore the disturbed intestinal microbiota composition, including that of Bacteroides, Akkermansia, and Intestinimonas to normal levels. Furthermore, DC significantly reduced the mRNA and protein levels of glucose-regulated protein 78, protein kinase R-like ER kinase, and eukaryotic initiation factor 2α. Taken together, DC outperformed DR in relieving dyspepsia by regulating gut microbiota and alleviating ER stress.

Plasma-assisted nitrogen doping in Ni-Co-P hollow nanocubes for efficient hydrogen evolution electrocatalysis.

To surmount the issues of a limited specific surface area and slow electrolyte diffusion in composite electrocatalysts, three-dimensional (3D) porous hollow nanocubes are fabricated, in which bimetal Ni-Co phosphide composites are covered with nanoparticles. The abundant hollow space provides more active sites for the catalyst, and simultaneously ensures efficient mass transfer and electron transport during the hydrogen evolution reaction (HER). A plasma-assisted approach is employed for smart N-doping in the Ni-Co phosphide hollow nanocubes (N-Ni-Co-P HNCs). The N-Ni-Co-P HNC catalyst exhibits a remarkable HER performance in 1 M KOH, evidenced by the low overpotentials of 47.9 mV and 150.5 mV at the current density of 10 mA cm-2 and 50 mA cm-2, respectively, as well as the excellent long-time stability. Essentially, the N doping tailors the electronic states and optimizes the free energy of hydrogen adsorption (ΔGH*) greatly, and the 3D porous hollow structure with porous nanoparticles stacked enlarges the specific active area substantially. Their synergistic effects result in the remarkably enhanced catalytic activity for the HER.

Sulfur doping enhanced desorption of intermediates on NiCoP for efficient alkaline hydrogen evolution.

Electrocatalysts with high catalytic activity, high stability and low cost are critical to the hydrogen evolution reaction (HER). In this paper, sulfur(S)-doped NiCoP nanowire arrays on a carbon fiber paper skeleton (S-NiCoP NW/CFP) are prepared, and it is demonstrated that the electrocatalytic properties of NiCoP in alkaline solution could be well improved by sulfur doping. In 1.0 M KOH, only an overpotential of 172 mV (vs. RHE) at 100 mA cm-2 is required for S doped NiCoP nanowires on CFP, and the turnover frequency (TOF) is 1.71 times that of NiCoP at an overpotential of 100 mV, indicating its superior intrinsic activity. Density functional theory (DFT) calculations show that S doping could lower the center of the d-band, and thus weaken the interaction between NiCoP and the intermediates. This leads to an optimized hydrogen adsorption Gibbs free energy (ΔGH*) and faster desorption of OH*. This study offers a promising way to design and optimize electrocatalysts for the HER in alkaline solution.

Anisotropic tough poly(vinyl alcohol)/graphene oxide nanocomposite hydrogels for potential biomedical applications.

Hydrogels, one of the most important bioinspired materials, are receiving increasing attention because of their potential applications as scaffolds for artificial tissue engineering and vehicles for drug delivery, etc. However, these applications are always severely limited by their microstructure and mechanical behavior. Here we report the fabrication of a tough polyvinyl alcohol/graphene oxide (PVA/GO) nanocomposite hydrogel through a simple and effective directional freezing-thawing (DFT) technique. The resulting hydrogels show well-developed anisotropic microstructure and excellent mechanical properties with the assistance of DFT method and lamellar graphene. The hydrogels with anisotropic porous structures that consisted of micro-sized fibers and lamellas exhibit high tensile strengths, up to 1.85 MPa with a water content of 90%. More interestingly, the PVA/GO composite hydrogels exhibit the better thermostability, which can maintain the original shape when swollen in hot water (65 °C). In addition, the hydrogels with biocompatibility show good drug release efficiency due to the unique hierarchical structure. The successful synthesis of such hydrogel materials might pave the way to explore applications in biomedical and soft robotics fields.