Explore the vast range of titles available.

Developing robust nonprecious-metal electrocatalysts with high activity towards sluggish oxygen-evolution reaction is paramount for large-scale hydrogen production via electrochemical water splitting. Here we report that self-supported laminate composite electrodes composed of alternating nanoporous bimetallic iron-cobalt alloy/oxyhydroxide and cerium oxynitride (FeCo/CeO 2− x N x ) heterolamellas hold great promise as highly efficient electrocatalysts for alkaline oxygen-evolution reaction. By virtue of three-dimensional nanoporous architecture to offer abundant and accessible electroactive CoFeOOH/CeO 2− x N x heterostructure interfaces through facilitating electron transfer and mass transport, nanoporous FeCo/CeO 2− x N x composite electrodes exhibit superior oxygen-evolution electrocatalysis in 1 M KOH, with ultralow Tafel slope of ~33 mV dec −1 . At overpotential of as low as 360 mV, they reach >3900 mA cm −2 and retain exceptional stability at ~1900 mA cm −2 for >1000 h, outperforming commercial RuO 2 and some representative oxygen-evolution-reaction catalysts recently reported. These electrochemical properties make them attractive candidates as oxygen-evolution-reaction electrocatalysts in electrolysis of water for large-scale hydrogen generation. 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.

HighlightsZnxCuy alloy shell was in-situ formed on self-supported three-dimensional nanoporous Zn anode by anionic surfactant-assisted surface alloying of Zn and Cu.The self-supported nanoporous ZnxCuy/Zn anodes exhibit high-rate capability, outstanding reversibility and stability during Zn stripping/plating because of zincophilic ZnxCuy to guide uniform Zn deposition and facilitate Zn stripping.Aqueous Zn-ion batteries assembled with nanoporous ZnxCuy/Zn anode and KzMnO2 cathode achieve specific energy of as high as ~430 Wh kg‒1 and retain ~86% after long-term cycles for >700 h.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 ZnxCuy alloy shell guiding uniform Zn deposition with a zero nucleation overpotential and facilitating Zn stripping via the ZnxCuy/Zn galvanic couples, the self-supported nanoporous ZnxCuy/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 ZnxCuy/Zn anode and KzMnO2 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.

Electrochemical hydrogenation of quinoxaline presents a promising alternative to traditional methods, yet is suffering from low current density and Faradaic efficiency due to the hampered hydrogenation process. Herein, we develop a cocatalytic system of Ru single atoms doped Co 3 O 4 nanosheet (Ru SA /ns-Co 3 O 4 ) to optimize the interfacial H 2 O behavior by tuning the Ru single atoms concentration for accelerating the electrochemical hydrogenation of quinoxaline, which enables remarkable Faradaic efficiency of 82% toward 1,2,3,4-tetrahydroquinoxaline at high current density of 200 mA cm -2 . Detailed experimental and theoretical studies reveal that Ru single atoms trigger interfacial charge redistribution, inducing an asymmetric local electric field that reconstructs interfacial H 2 O molecules into an H-down configuration. This reorientation remodels the hydrogen-bonded water network, shortens the distance between hydrogen atoms and the Co 3 O 4 surface, regulates K•H 2 O availability, and enhances H 2 O dissociation to supply H*. Consequently, the membrane electrode assembly electrolyser exhibits a long-term stability of >100 h at 200 mA cm -2 . Our findings highlight the prospect of interfacial water microenvironment for electrochemical hydrogenation of unsaturated N-heterocyclic compounds, with promising applications for the electrosynthesis of other valuable chemicals. Electrochemical hydrogenation of quinoxaline is a promising alternative to traditional methods but is limited by low current density and Faradaic efficiency. Here, the authors report a Ru single atoms doped Co 3 O 4 nanosheet catalyst that regulates interfacial water to achieve excellent performance.

Potassium oxide (K 2 O) is used as a promotor in industrial ammonia synthesis, although metallic potassium (K) is better in theory. The reason K 2 O 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). Potassium oxide is used as a promotor in industrial ammonia synthesis, although metallic potassium is better in theory. Here, the authors demonstrate metallic potassium, an unstable metal that easily volatilizes at high temperature, can be used as a promotor for ammonia synthesis.

In recent years, obesity has become a key factor affecting human health. 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 leaf petroleum ether extract (MOPEE) on lipid accumulation by and 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.

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 E 2 (PGE 2 ). Furthermore, FH535 (β-catenin inhibitor) and MOA reversed PGE 2 -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.

[This corrects the article DOI: 10.3389/fphar.2020.523962.].[This corrects the article DOI: 10.3389/fphar.2020.523962.].

The electrochemical nitrogen reduction reaction (NRR) technique has great potential for alleviating the high fossil fuel consumption and carbon emissions of the industrial Haber-Bosch method for ammonia (NH 3 ) synthesis. Moreover, the NRR provides great prospects for fully exploiting renewable energy since NH 3 is a promising energy carrier without carbon emissions. However, the development of the NRR technique is limited by the lack of efficient catalysts. Great efforts have been made to develop high-efficiency catalysts thus far, in which density functional theory (DFT) calculations have played an important role in assisting catalyst design. Herein, we summarize the recent catalyst design strategies to boost the NRR performance, i.e., the activity and selectivity. Additionally, representative computational studies are reviewed, accompanied by insights into further improving the catalytic behavior. Finally, we briefly discuss the challenges and opportunities in catalyst design via DFT calculations. The purpose of this review is to motivate more intelligent design strategies for high-efficiency NRR.

Electrochemical hydrogenation of quinoxaline presents a promising alternative to traditional methods, yet is suffering from low current density and Faradaic efficiency due to the hampered hydrogenation process. Herein, we develop a cocatalytic system of Ru single atoms doped Co O nanosheet (Ru /ns-Co O ) to optimize the interfacial H O behavior by tuning the Ru single atoms concentration for accelerating the electrochemical hydrogenation of quinoxaline, which enables remarkable Faradaic efficiency of 82% toward 1,2,3,4-tetrahydroquinoxaline at high current density of 200 mA cm . Detailed experimental and theoretical studies reveal that Ru single atoms trigger interfacial charge redistribution, inducing an asymmetric local electric field that reconstructs interfacial H O molecules into an H-down configuration. This reorientation remodels the hydrogen-bonded water network, shortens the distance between hydrogen atoms and the Co O surface, regulates K•H O availability, and enhances H O dissociation to supply H*. Consequently, the membrane electrode assembly electrolyser exhibits a long-term stability of >100 h at 200 mA cm . Our findings highlight the prospect of interfacial water microenvironment for electrochemical hydrogenation of unsaturated N-heterocyclic compounds, with promising applications for the electrosynthesis of other valuable chemicals.

The drumstick tree ( Moringa oleifera Lam.) is a perennial crop that has gained popularity in certain developing countries for its high-nutrition content and adaptability to arid and semi-arid environments. Here we report a high-quality draft genome sequence of M. oleifera . This assembly represents 91.78% of the estimated genome size and contains 19,465 protein-coding genes. Comparative genomic analysis between M. oleifera and related woody plant genomes helps clarify the general evolution of this species, while the identification of several species-specific gene families and positively selected genes in M. oleifera may help identify genes related to M. oleifera ’s high protein content, fast-growth, heat and stress tolerance. This reference genome greatly extends the basic research on M. oleifera , and may further promote applying genomics to enhanced breeding and improvement of M. oleifera .