Designing robust and cost‐effective electrocatalysts based on Earth‐abundant elements is crucial for large‐scale hydrogen production through electrochemical water splitting. Here, nitrogen‐doped ...carbon engrafted Mo2N/CoN hybrid nanosheets that are seamlessly oriented on hierarchical nanoporous Cu scaffold (Mo‐/Co‐N‐C/Cu), as highly efficient electrocatalysts for alkaline hydrogen evolution reaction are reported. The constituent heterostructured Mo2N/CoN nanosheets work as bifunctional electroactive sites for both water dissociation and adsorption/desorption of hydrogen intermediates while the nitrogen‐doped carbon bridges electron transfers between electroactive sites and interconnective Cu current collectors by making use of Mo‐/Co‐N‐C bonds and intimate C/Cu contacts at interfaces. As a consequence of unique architecture having electroactive sites to be sufficiently accessible, self‐supported nanoporous Mo‐/Co‐N‐C/Cu hybrid electrodes exhibit outstanding electrocatalysis in 1 m KOH, with a negligible onset overpotential and a low Tafel slope of 47 mV dec−1. They only take overpotential of as low as 230 mV to reach current density of 1000 mA cm−2. When coupled with their electro‐oxidized derivatives that mediate efficiently the oxygen evolution reaction, the alkaline water electrolyzer can achieve ≈100 mA cm−2 at 1.622 V in 1 m KOH electrolyte, ≈0.343 V lower than the device constructed with commercially available Pt/C and Ir/C nanocatalysts immobilized on nanoporous Cu electrodes.
Heterogenous Mo2N/CoN nanosheets that are in situ engrafted with nitrogen‐doped carbon skin and vertically rooted on nanoporous Cu scaffold (Mo‐/Co‐N‐C/Cu) hold promise as robust and cost‐effective (pre‐)electrocatalytsts for hydrogen/oxygen evolution reactions. Associated with nanoporous architecture to facilitate electron transfer and offer abundant and sufficiently accessible active sites, nanoporous Mo‐/Co‐N‐C/Cu electrodes exhibit oustanding electrocatalytic performance for overall water splitting.
Electrochemical nitrogen reduction reaction (NRR) for ammonia synthesis has attracted great interest in recent years, which presents a carbon‐free alternative to the energy‐intensive Haber–Bosch ...process. Besides, NRR also provides a promising coverage route of renewable energy since NH3 is considered the second generation of hydrogen energy while possessing established technologies of liquefaction, storage, and transport. However, there are long‐term challenges in catalyst design for NRR due to its low intrinsic activity and unsatisfied selectivity. Fortunately, by conducting extensive explorations in this field, much progress is achieved in boosting the NRR performance. Herein, from a view of the atomic/electronic level, three promotion effects are summarized for NRR (i.e., electron effect, geometry effect, and ligand effect), which tackle the challenges of activity and selectivity. Representative studies with taking fully advantages of the promotion effects are reviewed, which realized remarkable NRR performance. Finally, the future research directions and prospects are discussed. It is highly expected that this review will enable the advancement of NRR catalysts and promote the further development of electrochemical NRR.
This review summarizes recent progress in computation‐guided catalyst design to tackle the challenges of the activity and selectivity for nitrogen reduction reaction (NRR). From a view of the atomic/electronic level, three promotion effects (i.e. electron effect, geometry effect, and ligand effect) are proposed to boost the NRR performance. Representative catalysts with taking fully advantages of the promotion effects are reviewed.
Maslinic acid is a pentacyclic triterpenoid that is distributed in the peel of olives. Previous studies found that maslinic acid inhibited inflammatory response and antioxidant effects. We ...investigated whether maslinic acid ameliorates nonalcoholic fatty liver disease in mice with high‐fat‐diet (HFD)‐induced obesity and evaluated the regulation of lipogenesis in hepatocytes. Male C57BL/6 mice fed a normal diet or HFD (60% fat, w/w) were tested for 16 wk. After the fourth week, mice were injected intraperitoneally with maslinic acid for 12 wk. In another experiment, HepG2 cells were treated with oleic acid to induce lipid accumulation or maslinic acid to evaluate lipogenesis. Maslinic acid significantly reduced body weight compared with HFD‐fed mice. Maslinic acid reduced liver weight and liver lipid accumulation and improved hepatocyte steatosis. Furthermore, serum glucose, leptin, and free fatty acid concentrations significantly reduced, but the serum adiponectin concentration was higher, in the maslinic acid group than in the HFD group. In liver tissue, maslinic acid suppressed transcription factors involved in lipogenesis and increased adipose triglyceride lipase. In vitro, maslinic acid decreased lipogenesis by activating AMPK. These findings suggest that maslinic acid acts against hepatic steatosis by regulating enzyme activity involved in lipogenesis, lipolysis, and fatty acid oxidation in the liver.—Liou, C.‐J., Dai, Y.‐W., Wang, C.‐L., Fang, L.‐W., Huang, W.‐C. Maslinic acid protects against obesity‐induced nonalcoholic fatty liver disease in mice through regulation of the Sirt1/AMPK signaling pathway. FASEB J. 33, 11791‐11803 (2019). www.fasebj.org
Tea polyphenols (TPs) are important secondary metabolites in tea and are active in the food and drug industry because of their rich biological activities. In diet and food production, TPs are often ...in contact with other food nutrients, affecting their respective physicochemical properties and functional activity. Therefore, the interaction between TPs and food nutrients is a very important topic. In this review, we describe the interactions between TPs and food nutrients such as proteins, polysaccharides, and lipids, highlight the forms of their interactions, and discuss the changes in structure, function, and activity resulting from their interactions.
In the complex and variable marine environment, the navigation and localization of autonomous underwater vehicles (AUVs) are very important and challenging. When the conventional Kalman filter (KF) ...is applied to the cooperative localization of leader–follower AUVs, the outliers in the sensor observations will have a substantial adverse effect on the localization accuracy of the AUVs. Meanwhile, inaccurate noise covariance matrices may result in significant estimation errors. In this paper, we proposed an improved Sage–Husa adaptive extended Kalman filter (improved SHAEKF) for the cooperative localization of multi-AUVs. Firstly, the measurement anomalies were evaluated by calculating the Chi-square test statistics based on the innovation. The detection threshold was determined according to the confidence level of the Chi-square test, and the Chi-square test statistics exceeding the threshold were regarded as measurement abnormalities. When measurement anomalies occurred, the Sage–Husa adaptive extended Kalman filter algorithm was improved by suboptimal maximum a posterior estimation using weighted exponential fading memory, and the measurement noise covariance matrix was adjusted online. The numerical simulation of leader–follower multi-AUV cooperative localization verified the effectiveness of the improved SHAEKF and demonstrated that the average root mean square and the average standard deviation of the localization errors based on the improved SHAEKF were significantly reduced in the case of the presence of measurement abnormalities.
Scope: The proliferation and differentiation of intestinal stem cells (ISCs) are the basis of intestinal renewal and regeneration, and gut microbiota plays an important role in it. Dietary nutrition ...has the effect of regulating the activity of ISCs; however, the regulation effect of α‐linolenic acid (ALA) has seldom been reported.
Methods and Results: After intervening mice with different doses of ALA for 30 days, it is found that ALA (0.5 g kg−1) promotes small intestinal and villus growth by activating the Wnt/β‐catenin signaling pathway to stimulate the proliferation of ISCs. Furthermore, ALA administration increases the abundance of the Ruminococcaceae and Prevotellaceae, and promotes the production of short‐chain fatty acids (SCFAs). Subsequent fecal transplantation and antibiotic experiments demonstrate that ALA on the proliferation of ISCs are gut microbiota dependent, among them, the functional microorganism may be derived from Ruminococcaceae. Administration of isobutyrate shows a similar effect to ALA in terms of promoting ISCs proliferation. Furthermore, ALA mitigates 5‐fluorouracil‐induced intestinal mucosal damage by promoting ISCs proliferation.
Conclusion: These results indicate that SCFAs produced by Ruminococcaceae mediate ALA promote ISCs proliferation by activating the Wnt/β‐catenin signaling pathway, and suggest the possibility of ALA as a prebiotic agent for the prevention and treatment of intestinal mucositis.
In this work, it is shown that short‐chain fatty acids (SCFAs) produced by Ruminococcaceae mediate α‐linolenic acid (ALA) promote intestinal stem cells (ISCs) proliferation by activating the Wnt/β‐catenin signaling pathway, and suggest the possibility of ALA as a prebiotic agent for the prevention and treatment of intestinal mucositis.
Ammonia (NH3) is essential for modern agriculture and industry, and, due to its high hydrogen density and no carbon emission, it is also expected to be the next‐generation of “clean” energy carrier. ...Herein, directly from air and water, a plasma‐electrocatalytic reaction system for NH3 production, which combines two steps of plasma‐air‐to‐NOx− and electrochemical NOx− reduction reaction (eNOxRR) with a bifunctional catalyst, is successfully established. Especially, the bifunctional catalyst of CuCo2O4/Ni can simultaneously promote plasma‐air‐to‐NOx− and eNOxRR processes. The easy adsorption and activation of O2 by CuCo2O4/Ni greatly improve the NOx− production rate at the first step. Further, CuCo2O4/Ni can also resolve the overbonding of the key intermediate of *NO, and thus reduce the energy barrier of the second step of eNOxRR. Finally, the “green” NH3 production achieves excellent FENH3 (96.8%) and record‐high NH3 yield rate of 145.8 mg h−1 cm−2 with large partial current density (1384.7 mA cm−2). Moreover, an enlarged self‐made H‐type electrolyzer improves the NH3 yield to 3.6 g h−1, and the obtained NH3 is then rapidly converted to a solid of magnesium ammonium phosphate hexahydrate, which favors the easy storage and transportation of NH3.
A bifunctional catalyst of CuCo2O4/Ni applying to plasma‐electrocatalytic synthesis of NH3 from air and water is proposed, with which a record‐high NH3 yield rate of 145.8 mg h−1 cm−2 and excellent FE of 96.8% can be obtained. Moreover, the reaction system is enlarged and the generated NH3 precipitates into MgNH4PO4·6H2O solid to promote the practical application.
Display omitted
•S2O82-/Fe2+ system could remove total microbes and antibiotic resistant microbes efficiently.•SO4•- and Fe(IV) might participate the process of microbes removal.•Bacterial community ...structure shifted and the α-diversity reduced after persulfate treatment.•Actived persulfate had no toxicity to Oryzias latipes (freshwater and seawater).
Sewage in WWTPs is one of main way to spread antibiotic resistant microbes (ARMs), and beach bay water is in direct contact with human skin. It is necessary to pay attention to remove the ARMs in WWTP sewage and bay water. Our results showed that ARMs and total microbes (TMs) can be effectively removed by S2O82-/Fe2+ in the effluent stage of WWTPs and bay water. Quenching experiments using tert-butyl alcohol, dimethyl sulfoxide and Al2O3 as scavengers confirmed that the primary reactive oxidants responsible for microbes removal during the Fe(II)-activated persulfate oxidation process might be SO4•- and Fe(IV), rather than •OH. The bacterial community shifted and the alpha diversity significantly reduced after treatment. In WWTP group, relative abundance of Firmicutes increased to 8.56%, and potential pathogens such as genus Vibrio decreased to 0.03% in bay water after treatment. The ecological toxicity to the environment of S2O82-/Fe2+ further illustrated that the mortality of indicator species Oryzias latipes did not increase after treatment, and the dosage of 60/30 μM can be potentially ideal dosage of S2O82-/Fe2+. This study revealed Fe(II)-activated persulfate oxidation as an eco-friendly and economical method could reduce TMs and ARMs in WWTP sewage and bay water.
In early event detection, the ability to detect events at an earlier stage means to have more ample time for processing. The purpose of this study is to apply few-shot learning to early event ...detection based on infinite mixture prototypes. we present a design to distribute the early event detection issues across the loss function and the data task setting in few-shot learning, and the adoption of infinite mixture models helps to resolve the multi-model distribution of the pattern of early events. The proposed algorithm is evaluated on the CK＋database. The experimental results demonstrate not only feasible performance in terms of accuracy and detection time but also alignment with our hypothesis through the observation of generated clusters.
•Early event detection is conducted based on infinite mixture prototypes.•The pattern of early events of facial expressions exhibits a multi-modal distribution.•It is a few-shot learning method.
PDF
