Structural characterization and mast cell stabilizing activity of Red-edge tea polysaccharide.

The potential anti-allergic properties of tea have been demonstrated in studies supporting theanine and catechin. However, research on tea polysaccharides' anti-allergic properties has been limited. In this study, we extracted red-edge tea crude polysaccharide (RETPS) and evaluated its anti-allergic activity using the mast cell, passive cutaneous anaphylaxis, and passive systemic anaphylaxis models. We purified RETPS using the DEAE-52 cellulose column, analyzed its composition and structural characteristics, and compared the anti-allergic properties of different polysaccharide fractions. The purified components RETPS-3 and RETPS-4 displayed higher galacturonic acid content and lower molecular weight (106.61 kDa and 53.95 kDa, respectively) compared to RETPS (310.54 kDa). In addition, RETPS-3 and RETPS-4 demonstrated superior anti-allergic activity than RETPS in mice's passive cutaneous and systemic allergic reactions. Our findings provide evidence of the anti-allergic potential of tea polysaccharides and offer a theoretical foundation for developing tea polysaccharides as a functional anti-allergic food product.

Hierarchical CoWO4/NixFeyS microspheres bearing crystalline-amorphous interface as a multifunctional platform for outperformed water splitting and sensitive hydrazine sensing.

Highly efficient and multifunctional electrocatalysts are of high value in energy transformation and electrochemical sensing. Herein, hierarchically architectured cobalt tungstate/nickel iron sulfide (CoWO4/NixFeyS) microspheres with a crystalline-amorphous interface have been prepared on bimetallic substrate of nickel-iron foam (NIF) by a two-step hydrothermal method. Electrochemical characterization shows that CoWO4/NixFeyS microspheres can boost the electrocatalytic activity effectively through the synergistic effect on the crystalline-amorphous interface. When the CoWO4/NixFeyS is applied as the electrocatalysts for oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER), the overpotentials at a high current density of 500 mA cm-2 are only 322.8 mV and 306.5 mV, respectively. The overall water splitting device composed of CoWO4/NixFeyS/NIF couple only needs a cell voltage of 1.80 V to reach a current density of 100 mA cm-2, and 2.19 V to reach 500 mA cm-2. The CoWO4/NixFeyS/NIF can be also utilized as an effective electrochemical platform for the sensing of toxic hydrazine in a wide range from 50 µM to 17.3 mM, with a detection limit of 46.4 µM. All these results display that the CoWO4/NixFeyS/NIF can be a high-performance multifunctional material for energy transformation and environmental pollutant monitoring.

Protein arginine methyltransferase 8 regulates ferroptosis and macrophage polarization in spinal cord injury via glial cell-derived neurotrophic factor.

OBJECTIVE: To explore the influence of protein arginine methyltransferase 8 (PRMT8) regulating glial cell-derived neurotrophic factor (GDNF) on neuron ferroptosis and macrophage polarization in spinal cord injury (SCI). METHODS: A rat model of SCI was established through an injury induced by an external force. Basso, Beattie, and Bresnahan score, hematoxylin and eosin staining, and immunofluorescence were used, respectively, to detect changes in rat locomotion, spinal cord histopathology, and NeuN expression in the spinal cord. Iron content in the spinal cord and levels of malondialdehyde and glutathione were measured using detection kits. Transmission electron microscopy was used to reveal the morphological characteristics of mitochondria. Western blotting was performed to detect PRMT8, GDNF, cystine/glutamate transporter XCT, glutathione peroxidase 4, 4-hydroxynonenal, heme oxygenase-1, inducible nitric oxide synthase (iNOS), CD16, and arginase 1 (Arg1). The expression levels of iNOS and Arg1 in the spinal cord were visualized by immunofluorescence. ELISA was performed to measure the expression levels of IL-6, IL-1ß, and TNF-α. Rat dorsal root ganglion (DRG) neurons and RMa-bm rat macrophages were treated with lipopolysaccharide under hypoxic conditions. The viability and iron content of the neurons were detected using Cell Counting Kit-8 and a specific probe, respectively. Flow cytometry and immunofluorescence were used to assess macrophage polarization. Chromatin immunoprecipitation was used to identify the binding of PRMT8 to the GDFN promoter. RESULTS: Neuronal ferroptosis and M1 macrophage polarization were promoted, and PRMT8 expression was downregulated in SCI. PRMT8 overexpression exerted therapeutic effects on injured DRG neurons and RMa-bm cells. Moreover, PRMT8 overexpression inhibited ferroptosis and M1 macrophage polarization in rats with SCI. PRMT8 promoted GDNF expression by catalyzing H3K4 methylation. Knockdown of GDNF counteracted the therapeutic effects of PRMT8 overexpression. CONCLUSION: Overexpression of PRMT8 may inhibit ferroptosis and M1 macrophage polarization by increasing GDNF expression, thereby alleviating SCI.

Conditioned medium from bone marrow mesenchymal stem cells relieves spinal cord injury through suppression of Gal-3/NLRP3 and M1 microglia/macrophage polarization.

The therapeutic effects of bone marrow mesenchymal stem cells (BMSCs) and their conditioned media have been well-documented. This study focused on the effects of BMSC-conditioned medium (BMSCcm) on spinal cord injury (SCI). To study the effects of BMSCcm on rat motor function, inflammatory response, and M1/M2 macrophage/microglial polarization, SCI model rats were treated with BMSCcm and vectors for overexpression of galectin-3 (Gal-3) or NLR family pyrin domain containing 3 (NLRP3). Treatment with BMSCcm reduced the expression of Gal-3 and NLRP3, alleviated the inflammatory response, suppressed M1 microglia/macrophage polarization, and triggered M2 microglia/macrophage polarization in SCI model rats. Meanwhile, overexpression of Gal-3 or NLRP3 counteracted the suppressive effect of BMSCcm on SCI. Moreover, during BMSCcm treatment, overexpression of Gal-3 promoted the expression of NLRP3, whereas overexpression of NLRP3 had no significant effect on the expression of Gal-3. Additionally, the effects of BMSCcm on macrophage/microglial polarization and the underlying molecular mechanisms were observed in vitro. This study demonstrated that BMSCcm alleviates SCI by suppressing the expression of Gal-3 and NLRP3.

Single-Step Synthesis of Fe-Fe3 O4 Catalyst for Highly Efficient and Selective Electrochemical Nitrogen Reduction.

Nitrogen reduction electrocatalysts are highly attractive for catalytic science. However, most electrocatalysts are limited by their low faradaic efficiency, poor ammonia yield, and tedious and costly catalyst synthesis process. In this work, Fe-based oxide composite nanoparticles with steady chemical states are prepared by a single-step green procedure under ambient conditions. The resulting Fe-Fe3 O4 demonstrates remarkable activity and selectivity for nitrogen reduction reaction (NRR) with the highest faradaic efficiency of 53.2±1.8 % and NH3 yield rate of 24.6±0.8 µg h-1 mgcat. -1 at -0.4 V (vs. RHE) in 0.1 m Na2 SO4 electrolyte. Characterization experiments and theoretical calculation reveal that Fe-Fe3 O4 exhibits significantly enhanced charge transfer capability and suppresses the competitive HER process.

Facilitative role of circPVT1 in osteogenic differentiation potentials of bone marrow mesenchymal stem cells from patients with osteoporosis through the miR-30d-5p/ITGB3 axis.

OBJECTIVE: The critical role of circular RNAs (circRNAs) in osteoporosis (OP) has been highlighted. We tried to explore the role of circPVT1 in OP in relation to microRNA-30d-5p (miR-30d-5p) and ITGB3. METHODS: After bone marrow collection, bone marrow mesenchymal stem cells (BMSCs) were isolated and identified. Then, Pearson coefficient was used to analyze the correlation among circPVT1, miR-30d-5p and ITGB3, and the binding sites were predicted and verified. Gain- and loss-of function assays in circPVT1, miR-30d-5p and ITGB3 were performed to analyze their effect on osteogenic differentiation of BMSCs. RESULTS: The osteogenic differentiation of BMSCs from OP patients was significantly decreased, and reduced circPVT1 expression was found in the BMSCs from OP patients. Overexpression of circPVT1 stimulated the formation of calcified nodules, increased alkaline phosphatase activity, and enhanced the expression of osteogenic marker genes in the BMSCs from OP patients. Additionally, circPVT1 expression was negatively correlated with miR-30d-5p, and miR-30d-5p was negatively correlated with ITGB3 in OP patients. Mechanically, circPVT1 regulated the osteogenic differentiation potential of BMSCs by relieving the inhibition of miR-30d-5p on ITGB3 through the competitive endogenous RNA mechanism. CONCLUSION: Our study highlighted a circPVT1/miR-30d-5p/ITGB3 axis in regulating osteogenic differentiation potential of BMSCs from OP patients.

IL1RN promotes osteoblastic differentiation via interacting with ITGB3 in osteoporosis.

The occurrence and progress of osteoporosis (OP) are partially caused by impaired osteoblast differentiation. Interleukin-I receptor antagonist (IL1RN) is an immune modulatory molecule that commonly functions by means of competing the binding site of IL-1R with IL-1. Although it was recently reported that IL1RN is involved in osteoblast differentiation, the role of IL1RN in osteogenesis remains unclear. In this work, we first investigated the expression pattern of IL1RN in ovariectomy mice and in vitro osteogenic induction of MC3T3-E1 and C3H10T1/2 cells. To verify the exact role of IL1RN in osteoblast differentiation, we established IL1RN-downregulated/upregulated cell lines. The results indicated that IL1RN was constantly expressed in MC3T3-E1 and C3H10T1/2 cells. Interestingly, an increase of IL1RN expression in osteoblasts occurred when osteoblasts were cultured in osteogenic medium (OM). As expected, silencing of IL1RN attenuated the osteogenic effect of OM, while IL1RN overexpression increased the osteogenic staining and promoted the expression of osteogenic markers, including alkaline phosphatase, osterix, and osteocalcin. In addition to evaluating the function of IL1RN in osteoblasts, we also investigated the molecular mechanism of the role of IL1RN in osteoblasts. We found that IL1RN interacts with integrin ß3 to activate ß-catenin signaling, which finally regulates osteoblast differentiation. Taken together, this study provides the framework that IL1RN, as a novel regulator of osteogenesis, may be a potential therapeutic target for the treatment of OP.

Bonding interface boosts the intrinsic activity and durability of NiSe@Fe2O3 heterogeneous electrocatalyst for water oxidation.

The intrinsic activity and durability of oxygen evolution reaction (OER) electrocatalysts are mainly dominated by the surface and interface properties of active materials. Herein, a core-shell heterogeneous structure (NF/NiSe@Fe2O3) is fabricated via two-step hydrothermal method, which exhibits a low overpotential of 220 mV (or 282 mV) at 10 mA/cm2 (or 200 mA/cm2), a small Tafel slope of 36.9 mV/dec, and long-term stability (~230 h) in 1 mol/L KOH for OER. X-ray photoelectron spectroscopy and X-ray absorption spectroscopy reveal the (oxy)hydroxide-rich surface and strong coupling interface between NiSe and Fe2O3 via the Fe-Se bond. Density functional theory calculation suggests that the d-band center and electronic state of NiSe@Fe2O3 heterojunction are well optimized due to the formation of Fe-Se bond, which is favorable for the enhanced OER activity because of the easy adsorption of oxygen-containing intermediates and desorption of O2 in the OER process. In addition, the unique core-shell structure and robust bonding interface are responsible for the good stability for OER. This work provides fundamental insights on the bonding effect that determine the performance of OER electrocatalyst.

A novel MoNi@Ni(OH)2 heterostructure with Pt-like and stable electrocatalytic activity for the hydrogen evolution reaction.

A novel Mo0.84Ni0.16@Ni(OH)2 heterostructure was successfully fabricated. Owing to the unique interface structure and strong synergistic effects between different components, the heterostructure shows enhanced activity for the hydrogen evolution reaction (HER), outperforming that of the state-of-the-art Pt/C catalyst.

Coupling FeSe2 with CoSe: an effective strategy to create stable and efficient electrocatalysts for water oxidation.

A novel CoSe/FeSe2 nanohybrid electrocatalyst was prepared by a simple one-step hydrothermal method. Owing to the unique interface structure, abundant internal defects, good hydrophilia and electrical coupling effects between different components, the hybrid shows enhanced oxygen evolution reaction (OER) performances, better than those of the individual CoSe and FeSe2.

In situ growth of well-ordered NiFe-MOF-74 on Ni foam by Fe2+ induction as an efficient and stable electrocatalyst for water oxidation.

Well-ordered NiFe-MOF-74 is in situ grown on Ni foam by the induction of Fe2+ and directly used as an OER electrocatalyst. Benefited from the intrinsic open porous structure of MOF-74, the in situ formed MOF arrays and the synergistic effect of Ni and Fe, outstanding water oxidation activity is obtained in alkaline electrolytes with an overpotential of 223 mV at 10 mA cm-2.

Selenization of NiMn-layered double hydroxide with enhanced electrocatalytic activity for oxygen evolution.

Exploiting highly active oxygen evolution reaction electrocatalysts is of great importance in the cost-effective generation of clean fuels. Herein, the preparation of NiMn-layered double hydroxide with selenization is adopted to reduce the charge transfer resistance of the electrocatalytic oxygen evolution reaction and enhance electrocatalytic performance. As a result, this selenization product of NiMn-layered double hydroxide can reach a current density of 10 mA cm-2 at a low overpotential of 280 mV on glassy carbon electrode in 1.0 M KOH aqueous solution and have excellent stability, which makes them comparable to the most efficient IrO2 catalyst and better than most nickel based catalysts.

Hierarchical Fe-doped Ni3Se4 ultrathin nanosheets as an efficient electrocatalyst for oxygen evolution reaction.

Developing highly efficient oxygen evolution reaction (OER) electrocatalysts is critical to the cost-effective generation of clean fuels. Transition-metal selenides have been proposed to be OER catalyst alternatives to noble metal based catalysts, but generally exhibit limited electrocatalytic activity. We here report hierarchical Fe-doped Ni3Se4 ((Ni,Fe)3Se4) ultrathin nanosheets as an efficient electrocatalyst for OER in alkaline electrolytes. The preparation involves a solvothermal synthesis and a topotactic conversion process. The prepared hierarchical (Ni,Fe)3Se4 ultrathin nanosheets show abundant and accessible catalytically active sites, facile charge transfer and a high specific surface area. Relative to the Ni3Se4 nanosheets, the as-prepared (Ni,Fe)3Se4 ultrathin nanosheets show a higher current density and a lower Tafel slope towards the OER. Remarkably, hierarchical (Ni,Fe)3Se4 ultrathin nanosheets supported on Ni foam exhibit an electrocatalytic OER with a current density of 10 mA cm-2 at a low overpotential of 225 mV and a small Tafel slope of about 41 mV dec-1. This study establishes (Ni,Fe)3Se4 ultrathin nanosheets as an efficient electrocatalyst for the OER that can be used in the fields of metal-air batteries and water splitting for hydrogen production.

Near-infrared persistent luminescence of Yb3+ in perovskite phosphor.

Here we report the observation of near-infrared persistent luminescence (NIR PersL) of Yb3+ in perovskite CaTiO3. Sensitized by the Bi3+ codopants, it exhibits intense NIR PersL of Yb3+ at about 1000 nm. In addition, this phosphor can be excited by the near ultraviolet and even visible light, and the PersL signals can be recorded for more than 80 h. The PersL enhancement by Bi3+ is revealed to be due to the suitable Bi3+ induced deeper traps and the possible PersL quantum cutting. The results suggest that the NIR PersL of the CaTiO3:Yb3+, Bi3+ phosphor has potential applications for biomedical imaging in the second biological window.

Near-Infrared Quantum Cutting Long Persistent Luminescence.

By combining the unique features of the quantum cutting luminescence and long persistent luminescence, we design a new concept called "near-infrared quantum cutting long persistent luminescence (NQPL)", which makes it possible for us to obtain highly efficient (>100%) near-infrared long persistent luminescence in theory. Guided by the NQPL concept, we fabricate the first NQPL phosphor Ca2Ga2GeO7:Pr(3+),Yb(3+). It reveals that both the two-step energy transfer of model (I) and the one-step energy transfer of model (IV) occur in (3)P0 levels of Pr(3+). Although the actual efficiency is not sufficient for the practical application at this primitive stage, this discovery and the associated materials are still expected to have important implications for several fields such as crystalline Si solar cells and bio-medical imaging.

Self-Activated Photostimulated Luminescence Properties and Stable Storage Capacity of Un-Doped Sr3Al2O5Cl2 Material for Potential Applications in Optical Storage.

Un-doped Sr3Al2OCl2 material is synthesized by conventional solid state method in reducing atmosphere. It shows intense photostimulated luminescence and the emission band of spectrum covers in 420-800 nm under infrared laser (980 nm) stimulation. Both the emission centers and traps are related to oxygen-deficient defects. Moreover, thermoluminescence indicates that there are at least five types of traps levels in this material. The weak long lasting phosphorescence (30 s) implies the lack of the shallow traps. The deep traps are rich and their storage capacity can be influenced by the releasing progress of the shallow traps. When the shallow traps are completely emptied after 6 h, the stable storage capacity of deep traps is still as large as 51.5%. Also, this material show good photostimulated luminescence under irradiation by infrared laser. Therefore, the un-doped Sr3Al2O5Cl2 material synthesized in reducing atmosphere can be considered as a potential photostimulated material for optical storage. Accordingly, the influence mechanism of traps on photostimulated luminescence is proposed.