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Abstract Potassium oxide (K2O) is used as a promotor in industrial ammonia synthesis, although metallic potassium (K) is better in theory. The reason K2O is used is because metallic K, which volatilizes around 400 °C, separates from the catalyst in the harsh ammonia synthesis conditions of the Haber-Bosch process. To maximize the efficiency of ammonia synthesis, using metallic K with low temperature reaction below 400 °C is prerequisite. Here, we synthesize ammonia using metallic K and Fe as a catalyst via mechanochemical process near ambient conditions (45 °C, 1 bar). The final ammonia concentration reaches as high as 94.5 vol%, which was extraordinarily higher than that of the Haber-Bosch process (25.0 vol%, 450 °C, 200 bar) and our previous work (82.5 vol%, 45 °C, 1 bar).

Developing stable catalysts for industrial-scale current densities is challenging. Here, the authors report self-supported laminate electrodes composed of nanoporous bimetallic iron-cobalt alloy/oxyhydroxide and cerium oxynitride hybrid that can catalyze the oxygen evolution reaction at high current densities.

Abstract Metallic zinc (Zn) is one of the most attractive multivalent-metal anode materials in post-lithium batteries because of its high abundance, low cost and high theoretical capacity. However, it usually suffers from large voltage polarization, low Coulombic efficiency and high propensity for dendritic failure during Zn stripping/plating, hindering the practical application in aqueous rechargeable zinc-metal batteries (AR-ZMBs). Here we demonstrate that anionic surfactant-assisted in situ surface alloying of Cu and Zn remarkably improves Zn reversibility of 3D nanoporous Zn electrodes for potential use as high-performance AR-ZMB anode materials. As a result of the zincophilic Zn x Cu y alloy shell guiding uniform Zn deposition with a zero nucleation overpotential and facilitating Zn stripping via the Zn x Cu y /Zn galvanic couples, the self-supported nanoporous Zn x Cu y /Zn electrodes exhibit superior dendrite-free Zn stripping/plating behaviors in ambient aqueous electrolyte, with ultralow polarizations under current densities up to 50 mA cm‒2, exceptional stability for 1900 h and high Zn utilization. This enables AR-ZMB full cells constructed with nanoporous Zn x Cu y /Zn anode and K z MnO2 cathode to achieve specific energy of as high as ~ 430 Wh kg‒1 with ~ 99.8% Coulombic efficiency, and retain ~ 86% after long-term cycles for > 700 h.

Moringa oleifera Lam. (M. oleifera) is valuable plant distributed in many tropical and subtropical countries. It has a number of medicinal uses and is highly nutritious. M. oleifera has been shown to inhibit tumor cell growth, but this effect has not been demonstrated on prostate cancer cells. In this study, we evaluated the inhibitory effect of M. oleifera alkaloids (MOA) on proliferation and migration of PC3 human prostate cancer cells in vitro and in vivo. Furthermore, we elucidated the mechanism of these effects. The results showed that MOA inhibited proliferation of PC3 cells and induced apoptosis and cell cycle arrest. Furthermore, MOA suppressed PC3 cell migration and inhibited the expression of matrix metalloproteinases (MMP)-9. In addition, MOA significantly downregulated the expression of cyclooxygenase 2 (COX-2), β-catenin, phosphorylated glycogen synthase 3β, and vascular endothelial growth factor, and suppressed production of prostaglandin E2 (PGE2). Furthermore, FH535 (β-catenin inhibitor) and MOA reversed PGE2-induced PC3 cell proliferation and migration, and the effects of MOA and FH535 were not additive. In vivo experiments showed that MOA (150 mg/kg) significantly inhibited growth of xenograft tumors in mice, and significantly reduced the protein expression levels of COX-2 and β-catenin in tumor tissues. These results indicate that MOA inhibits the proliferation and migration, and induces apoptosis and cell cycle arrest of PC3 cells. Additionally, MOA inhibits the proliferation and migration of PC3 cells through suppression of the COX-2 mediated Wnt/β-catenin signaling pathway.

In recent years, obesity has become a key factor affecting human health. Moringa oleifera Lam. is a perennial tropical deciduous tree, which is widely used in human medicine due to its nutritional and unique medicinal value. It has a cholesterol-lowering effect, but its mechanism of action is unclear. In this study, we elucidated the inhibitory effect of M. oleifera leaf petroleum ether extract (MOPEE) on lipid accumulation by in vitro and in vivo experiments, and we described its mechanism of action. MOPEE suppressed adipogenesis in 3T3-L1 adipocytes in a dose-dependent manner and had no effect on cell viability at doses up to 400 μg/ml. Furthermore, MOPEE (400 μg/ml) significantly downregulated the expression of adipogenesis-associated proteins [peroxisome proliferator-activated receptor γ (PPARγ), CCAAT/enhancer-binding proteins α and β (C/EBPα and C/EBPβ), and fatty acid synthase (FAS)] and upregulated the expression of a lipolysis-associated protein [hormone-sensitive lipase (HSL)] in 3T3-L1 adipocytes. Additionally, MOPEE (400 μg/ml) significantly increased the degree of phosphorylation of AMP-activated protein kinase α (AMPKα) and acetyl-CoA carboxylase (ACC). An AMPK inhibitor reversed the MOPEE-induced activation of AMPKα and ACC in 3T3-L1 adipocytes. Animal experiments showed that, in high-fat diet (HFD) mice, MOPEE [0.5 g/kg body weight (BW)] effectively decreased BW; relative epididymal, perirenal, and mesenteric fat weight and fat tissue size; and hepatic fat accumulation. Furthermore, MOPEE markedly reduced the serum levels of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and aspartate aminotransferase (AST). Moreover, MOPEE significantly downregulated the expression of adipogenesis-associated proteins (PPARγ and FAS) and upregulated the expression of a lipolysis-associated protein [adipose triglyceride lipase (ATGL)] in HFD mice hepatic and epididymal fat tissue. Additionally, MOPEE markedly increased the degree of phosphorylation of AMPKα and ACC in HFD mice hepatic and epididymal fat tissue. Following ultrahigh-performance liquid chromatography quadrupole time-of-flight tandem mass spectrometry (UPLC-QTOF-MS/MS) analysis, three phytocompounds (isoquercitrin, chrysin-7-glucoside, and quercitrin) were identified as compounds with relatively high levels in MOPEE. Among them, quercitrin showed excellent fat accumulation inhibitory activity, and the three compounds had synergistic effects in inhibiting adipogenesis. Taken together, MOPEE inhibits fat accumulation by inhibiting the adipogenesis and promoting the lipolysis, and this process is related to AMPK activation.