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The non‐homogeneous gamma process can exhibit a convex average trend with a non‐linear shape parameter, providing significant flexibility in fitting an accelerated degradation process. However, few studies have been conducted on the maintenance modeling of systems undergoing a non‐homogeneous gamma degradation process despite its versatility. Meanwhile, most maintenance studies adopt a periodic inspection policy to reveal the degradation level. However, it is reasonable to inspect less frequently when the degradation level of the system is low and to perform inspections more frequently when the degradation level increases. Therefore, we conduct a study on the inspection/replacement policy of systems undergoing a non‐homogeneous gamma degradation process, where three non‐periodic inspection policies are investigated. We formulate the problem as a SMDP framework and present a value iteration algorithm to obtain the optimal action at each decision epoch that minimizes the long‐term average cost. A comprehensive numerical study is provided to illustrate the effectiveness of our proposed model. [ABSTRACT FROM AUTHOR]

Seawater electrolysis is an attractive way of making H2 in coastal areas, and NiFe‐based materials are among the top options for alkaline seawater oxidation (ASO). However, ample Cl− in seawater can severely corrode catalytic sites and lead to limited lifespans. Herein, we report that in situ carbon oxyanion self‐transformation (COST) from oxalate to carbonate on a monolithic NiFe oxalate micropillar electrode allows safeguard of high‐valence metal reaction sites in ASO. In situ/ex situ studies show that spontaneous, timely, and appropriate COST safeguards active sites against Cl− attack during ASO even at an ampere‐level current density (j). Our NiFe catalyst shows efficient and stable ASO performance, which requires an overpotential as low as 349 mV to attain a j of 1 A cm−2. Moreover, the NiFe catalyst with protective surface CO32− exhibits a slight activity degradation after 600 h of electrolysis under 1 A cm−2 in alkaline seawater. This work reports effective catalyst surface design concepts at the level of oxyanion self‐transformation, acting as a momentous step toward defending active sites in seawater‐to‐H2 conversion systems. [ABSTRACT FROM AUTHOR]

Electrical discharge machining (EDM) method is an innovative method for the fabrication of structured array surfaces on binderless tungsten carbide (WC) which is a typical embossing mold material, compared to traditional machining methods. To improve the convenience of electrode replacement and the fabrication efficiency of the structured array, a novel self‐assembly ball electrode is innovatively developed. The feasibility of machining binderless WC with a self‐assembly ball electrode was studied and its effect on profile deviation analyzed. Furthermore, the discharge condition's effect on surface roughness, material removal rate (MRR), and tool wear ratio (TWR) was investigated. The microstructure, phase structure, and element distribution of binderless WC caused by EDM were characterized by Raman spectroscopy, scanning electron microscopy, and energy dispersive x‐ray spectroscopy. The results indicated that the maximum profile deviation of the different random structured arrays was about 3.7 μm. The surface roughness of all structured arrays was below 1 μm. The maximum TWR was about 0.008 mm3/min. Besides, the binderless WC surface after EDM presented strong D and G carbon peaks, which means the precipitation and transformation of the WC phase during the discharge process. Finally, different kinds of self‐assembly ball electrodes are developed and used to fabricate the lens array structures on binderless WC. The fast fabrication of the micro‐lens array surfaces in different arrangements sheds some light on the design and manufacturing of other functional structured surfaces. [ABSTRACT FROM AUTHOR]

The coordination microenvironment of metal active sites in metal–organic frameworks (MOFs) plays a crucial role in its performance for electrochemical CO2 reduction reaction (CO2RR). However, it remains a challenge to clarify the structure–performance relationship for CO2RR catalyzed by MOFs. Herein, a series of MOFs with different coordination microenvironments of Cu(I) sites (CuCl, CuBr, and CuI) to evaluate their performances for CO2RR is synthesized. With the increasing radius of halogen atom, the CO2 adsorption capacity increases and d‐band center of Cu positively shifts to the Fermi level, leading to enhance the selectivity of CO2 to CH4 conversion. CuI gives the highest total Faradaic efficiency (FE) of 83.2%, with a FE of CH4 up to 57.2% and CH4 partial current density of 60.7 mA cm−2 at −1.08 V versus reversible hydrogen electrode. Theoretical calculations reveal that the shifted d‐band center of Cu site contributes to reduced formation energies of *CH2O and *CH3O intermediates, which is the potential‐determining step of CO2RR and thus facilitates the electrocatalytic CO2 reduction to CH4. This study opens a new avenue for studying the relationship between the coordination microenvironment of active site and electroreduction reaction performance of MOFs. [ABSTRACT FROM AUTHOR]

Glass‐embossing technology has attracted great attention due to its promise of low‐cost and environmentally conscious fabrication of well‐defined and controllable surfaces and nanostructured devices. The embossed surface quality of glass structures is a very important index for optics. However, the evolutions of nanosurfaces and their microcontact mechanism during glass‐embossing process have not been deeply and comprehensively investigated. Here, we studied the surface morphology evolution of optical glass under different processing conditions using a tungsten carbide surface plate with nanoscale roughness as the mold. The light transmittances of different embossed glasses were detected by an ultraviolet spectrophotometer. The flow deformation and microcontact mechanism of glass‐supercooled liquids were revealed during glass‐embossing process. The result showed that the rough optical glass can successfully replicate the nanoscale smoothness of the tungsten carbide template without grinding or polishing. On the basis of the previous study, the glass‐surfaced structures from nanoscale to macroscale are fabricated. This work provides better understanding for the evolution of nanosurfaces and the fabrication of nanostructured optics during glass‐embossing process. [ABSTRACT FROM AUTHOR]

Purposefully developing crystalline materials at molecular level to improve the selectivity of electroreduction CO2 to CH4 is still rarely studied. Herein, a single crystal of copper(II) complex with hydroxy groups was designed and synthesized, namely 5,10,15,20‐tetrakis(3,4‐dihydroxyphenyl)porphyrin copper(II) (Cu‐PorOH), which could serve as a highly efficient heterogeneous electrocatalyst for electroreduction of CO2 toward CH4. In 0.5 m KHCO3, Cu‐PorOH gave a high faradaic efficiency of 51.3 % for CH4 and drove a partial current density of 23.2 mA cm−2 at −1.5 V versus the reversible hydrogen electrode in H‐cell. The high performance was greatly promoted by the hydroxy groups in Cu‐PorOH, which could not only form stable three‐dimensional frameworks through hydrogen‐bonding interactions but also stabilize the intermediate species by hydrogen bonds, as supported by density functional theory calculations. This work provides an effective avenue in exploring crystalline catalysts for CO2 reduction at molecular level. [ABSTRACT FROM AUTHOR]

Contactless hot embossing has been demonstrated to possess the potential for cost‐effective production and precise mounting concepts in fabricating glass microlenses and microlens arrays due to the reduced difficulty of mold fabrication and the possibility of obtaining self‐aligned assemblies. This study aims to provide experimental evidence for understanding the forming mechanism of glass microlenses and microlens arrays in the contactless hot embossing process. The effects of process parameters, diameter and position of the micro‐holes, hole diameter, and pitch of the micro‐hole array mold on the filling deformation of glass in contactless hot embossing were comprehensively investigated. It is found that placing the micro‐hole farther away from the mold center renders decrease in both filling height and tip curvature but increase in the eccentricity of the embossed glass microlens. As a result, the formed glass microlens array shows a nonuniform distribution of filling height and tip curvature. Furthermore, reducing the pitch of micro‐hole array mold can significantly improve the uniformity of formed microlens array. Based on these experimental results, the forming mechanism of microlenses and microlens arrays in contactless hot embossing process is summarized. Finally, a glass microlens array with decent uniformity in the center area was hot embossed by using a SiC micro‐hole array mold. [ABSTRACT FROM AUTHOR]

Al2O3/(W, Ti)C/TiN/Mo/Ni multidimensional graded ceramics and homogeneous reference ceramic were prepared by two step hot press sintering. The thermal shock and thermal fatigue resistance of the multidimensional graded ceramics were tested using the water quenching method. Scanning electron microscopy (SEM) and optical microscope were used to investigate microscopic failure mechanism of ceramics. The results showed that the retained flexural strength of two‐dimensional and one‐dimensional graded ceramics was almost same, but higher than that of the homogeneous ceramic. The crack growth (∆c) of homogeneous ceramic increased rapidly, while that of two‐dimensional graded ceramics is the lowest. Hence, thermal fatigue resistance of the two‐dimensional graded ceramics was highest. The residual compressive stress in the first layer induced by the optimal graded structure played an important role. In addition, the increasing toughness on the crack propagation path by adding different amounts of metals was also a contributing factor. [ABSTRACT FROM AUTHOR]

Vanadates have received booming attention recently as promising materials for extensive electrochemical devices such as batteries and electrocatalysis. However, the enormous difficulties of achieving pure‐phase transition metal vanadates, especially for nickel‐based, hinder their exploitations. Herein, for the first time, by controlling the amount of ethylene glycol (EG) and reaction time, grape‐like Ni2V2O7 (or V2O5/Ni2V2O7) microspheres were rationally fabricated. It is demonstrated that the EG can chelate both Ni2+ and VO3− to form organometallic precursors. As anode in lithium‐ion batteries (LIBs), it could deliver superior reversible capacity of 1050 mAh/g at 0.1 A/g and excellent rate capability of 600 mAh/g at 4 A/g. The facile hydrothermal synthesis broadens the material variety of nickel vanadates and offers new opportunities for their wider applications in electrochemistry. [ABSTRACT FROM AUTHOR]

Background: pH‐sensitive peptides are a relatively new strategy for conquering the poor endosomal release of cationic polymer‐mediated transfection. Modification of antimicrobial peptides by exchanging positively‐charged residues with negatively‐charged glutamic acid residues (Glu) greatly improves its lytic activity at the endosomal pH, which could improve cationic polymer‐mediated transfection. Methods: In the present study, we investigated the effect of the number of Glu substituted for positively‐charged residues on the endosomal escape activity of AR‐23 and the ability of mutated AR‐23 with respect to enhancing cationic polymer‐mediated transfection. Three analogs were synthesized by replacing the positively‐charged residues in the AR‐23 sequence with Glu one‐by‐one. Results: The pH‐sensitive lysis ability of the peptides, the effect of peptides on the physicochemical characteristics, the intracellular trafficking, the transfection efficiency and the cytotoxicity of the polyplexes were determined. Increased lytic activity of peptides was observed with the increased number of Glu replacement in the AR‐23 sequence at acidic pH. The number of Glu substituted for positively‐charged residues of AR‐23 dramatically affects its lysis ability at neutral pH. Triple‐Glu substitution in the AR‐23 sequence greatly improved poly(l‐lysine)‐mediated gene transfection efficiency at the same time as maintaining low cytotoxicity. Conclusions: The results indicate that replacement of positively‐charged residues with sufficient Glu residues may be considered as a method for designing pH‐sensitive peptides, which could be applied as potential enhancers for improving cationic polymer‐mediated transfection. [ABSTRACT FROM AUTHOR]

The aim of this study was to thoroughly investigate the effect of temperature on the deformation behavior and optical performance of moulded glass in a nonuniform temperature field. Experiments and numerical simulations were used to analyze how different temperature gradients distributed across a glass cylinder affected the deformation behavior of the moulded glass. Additionally, the imaging quality of the moulded glass lens was detected using the optical measurement system. The results show that the overall shape of the moulded glass cylinder was mainly determined by the value of the temperature gradient. The larger temperature gradient led to smaller deformation angle θ in the moulded glass cylinder. Temperature difference inside the glass dominantly affected the deformation behavior and surface morphology in the nonuniform temperature field, which greatly determines the imaging quality of glass lenses. The results of this study are significant for glass lens fabrication. [ABSTRACT FROM AUTHOR]

Room-temperature sodium-ion batteries have attracted great attentions for large-scale energy storage applications in renewable energy. However, exploring suitable anode materials with high reversible capacity and cyclic stability is still a challenge. The VS4, with parallel quasi-1D chains structure of V4+(S22-)2, which provides large interchain distance of 5.83 Å and high capacity, has showed great potential for sodium storage. Here, the uniform cuboid-shaped VS4 nanoparticles are prepared as anode for sodium-ion batteries by the controllable of graphene oxide (GO)-template contents. It exhibits superb electrochemical performances of high-specific charge capacity (≈580 mAh·g-1 at 0.1 A·g-1), long-cycle-life (≈98% retain at 0.5 A·g-1 after 300 cycles), and high rates (up to 20 A·g-1). In addition, electrolytes are optimized to understand the sodium storage mechanism. It is thus demonstrated that the findings have great potentials for the applications in high-performance sodium-ion batteries. [ABSTRACT FROM AUTHOR]

A comprehensive study was conducted to analyze the quality dependence of a plano-concave molded glass lens on its own dimensions, i.e. the effective diameter, sag ratio, and center thickness ratio. To achieve this goal, a thermal-displacement coupled finite element analysis was carried out on the whole molding process, in order to get the results of curve deviation, temperature gradient, and residual stress with sets of variations in these dimensions. Then Taguchi method, one approach for design of experiments, was incorporated to conduct sensitivity analysis on the simulation results to figure out the dominating sequence of these dimensions. The results show that the effective diameter is the most influential factor among these three dimensions. In addition, curve deviation is sensitively proportional to diameter and sag ratio, but decreases insignificantly with greater center thickness ratio. However, residual stress is distinctly proportional to diameter and center thickness ratio, but increases very slightly with greater sag ratio. Results also confirmed the consequential relationship between temperature gradient and residual stress. These discoveries are fundamentally meaningful in getting an overall understanding of the dimensions' influence on the molded lens quality, thus will help make decision in choosing proper dimensions for optical design. [ABSTRACT FROM AUTHOR]

Background Poor endosomal release is a major barrier of polyplex-mediated gene transfection. Antimicrobial peptides (AMPs) are commonly used to improve polyethylenimine (PEI)-mediated gene transfection by increasing endosomal release. In the present study, we designed novel pH-sensitive peptides that highly enhance transfection efficiency compared to their parent peptides. Methods Two analogues of melittin (Mel) and RV-23 (RV) were synthesized by replacing the positively-charged residues in their sequences with glutamic acid residues. The pH-sensitive lysis ability of the peptides, the effect of the peptides on physicochemical characteristics, the intracellular trafficking, the transfection efficiency, and the cytotoxicity of the polyplexes were determined. Results The acidic peptides showed pH-sensitive lytic activity. The hemolytic activity of acidic peptides at pH 5.0 was higher than that at pH 7.4. The incorporation of acidic peptides did not affect the DNA binding ability of PEI but affected the physicochemical characteristics of the PEI/DNA polyplexes, which may be beneficial for endosomal release and gene transfection. The incorporation of acidic peptides into PEI/DNA polyplexes enhanced the PEI-mediated transfection efficiency corresponding to up to 42-fold higher luciferase activity compared to that of PEI alone. Conclusions The results of the present study indicate that replacement of positively-charged residues with glutamic acid residues in the AMP sequence yields pH-sensitive peptides, which enhance the transfection efficiency of PEI/DNA polyplexes in various cell lines. [ABSTRACT FROM AUTHOR]

There have been numerous studies concerning the associations of angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D), angiotensin II receptor 1 (AT1R) gene A1166C, and endothelial nitric oxide synthase (eNOS) gene 4b/a polymorphisms with risk of pregnancy hypertensive disorders (PHDs). However, the results are inconsistent. A total of 83 eligible studies (10,354/18,446 cases/controls) were included in this meta-analysis. Pooled odds ratios with corresponding 95% confidence intervals were used to calculate these associations. The effects of ethnicity and types of PHDs were also considered. Results showed significant associations between the ACE gene polymorphism and PHDs in all of the populations except that in Africa. The associations also existed in AT1R, eNOS gene polymorphism and PHDs in part of the gene models in the overall population. These results indicated the ACE gene polymorphism was associated with an increased risk of PHDs, whereas the eNOS and AT1R gene polymorphism only have increased susceptibility to PHDs in part of the gene models. [ABSTRACT FROM AUTHOR]

The synthesis of 2-thioxoquinazolinone derivatives was achieved by condensation of isatoic anhydride, primary amine, and under . This convenient and efficient method affords the desired products with good to excellent yields. Satisfactory , 1H NMR, and high-resolution (electrospray ionization) spectra were obtained for all compounds described. [ABSTRACT FROM AUTHOR]

Aims/Introduction Zinc-α2-glycoprotein ( ZAG) is associated with the loss of adipose tissue in cancer cachexia, and has recently been proposed to be a candidate factor in the regulation of bodyweight. The aim of the study was to investigate the effects of ZAG on the proliferation and differentiation of 3T3-L1 preadipocytes. Materials and Methods 3-(4,5-Dimethylthiazol-2-yl) 2,5-diphenyl tetrazolium bromide ( MTT) spectrophotometry, Oil Red O staining, intracellular triglyceride assays, real-time quantitative reverse transcription polymerase chain reaction and transient transfection methods were used to explore the action of ZAG. Results Ectopic ZAG expression significantly stimulates 3T3-L1 cells proliferation in a dose- and time-dependent manner. The maximum influence of ZAG on proliferation was 1.43-fold higher than what was observed in control cells. This effect was observed 144 h after transfection with 0.16 μg of murine ZAG ( mZAG) plasmid ( P < 0.001). The intracellular lipids content in mZAG over-expressing cells were decreased as much as 37% when compared with the control cells after differentiation ( P < 0.05, P < 0.01). The messenger ribonucleic acid levels of peroxisome proliferators-activated receptor-γ (PPARγ), CCAAT enhancer-binding protein-α (C/EBPα) and the critical lipogenic gene, fatty acid synthase (FAS), are also downregulated by up to 50% in fully differentiated ZAG-treated adipocytes. ZAG suppresses FAS messenger ribonucleic acid expression by reducing FAS promoter activity. Conclusions Zinc-α2-glycoprotein stimulates the proliferation and inhibits the differentiation of 3T3-L1 murine preadipocytes. The inhibitory action of ZAG on cell differentiation might be a result of the attenuation of the expression of PPARγ, C/ EBPα and the lipogenic-specific enzyme FAS by reducing FAS promoter activity. [ABSTRACT FROM AUTHOR]

Background Previous studies have suggested that reducing the positive charge of melittin could increase endosomal release activity and improve branched polyethylenimine (BPEI)-mediated transfection. AR-23 is a melittin-related peptide from Rana tagoi, which shows 81% sequence identity with melittin but has less positively-charged residues than melittin. The present study aimed to investigate the mechanistic and functional aspects of the interaction of AR-23 with mammalian cells and thus improve BPEI-mediated gene transfection. Methods AR23 and two AR-23 analogs (AR-20 without positively-charged residues and AR-26 with the same positively-charged residues as melittin) were analyzed. Circular dichroism (CD) spectrometry was used to analyze the secondary structures of the peptides. Peptide-induced depolarization of cell membrane, the membrane-lytic activity of the peptides, and their potency with respect to enhancing the cellular uptake of calcein were evaluated. The physicochemical characters of complexes were measured and the effect of the peptides on BPEI-mediated transfection was determined. Results The CD spectra results indicated that a positive charge in AR-23 played a crucial role in maintaining the α-helical conformation, whereas an extra positive charge could not increase α-helical formation. AR-23 displayed a similar depolarization ability to melittin. However, AR-23 showed a lower membrane lytic activity under physiological conditions and a higher lytic activity at endosomal pH than melittin and AR-26, which possess more positive charges. Compared to melittin and AR-26, AR-23, with a higher endosomal escaping activity, resulted in a higher enhancement of BPEI-mediated gene transfection, as well as the maintainance of a lower cytotoxicity. Conclusions We suggest that AR-23 may be considered as a potential enhancer for improving the transfection efficiency of cationic polymers. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Background Melittin is a commonly used cell-penetrating peptide (CPP) for improving branched polyethylenimine (BPEI)-mediated gene transfection. However, its application is limited owing to the cytotoxicity generated by the lytic activity at neutral pH. In the present study, we report two truncated peptides from melittin and florae with improved transfection efficiency. Methods Two truncated peptides consisting of 1-20 residues of melittin (MT20) and florae (FL20) were synthesized. Circular dichroism (CD) spectrometry was used to analyze the secondary structures of the peptides. The membrane-lytic activity of the peptides and their potency in enhancing cellular uptake of calcein were evaluated. The peptides and BPEI mixtures were mixed with plasmid DNA to prepare peptide/BPEI/DNA complexes. The physicochemical characters of complexes were measured and the effect of the peptides on BPEI-mediated transfection was determined. Results CD analysis and structure observation showed that the truncated peptides have α-helical conformation, which was necessary for penetrating activity. The truncated peptides exhibited several advantages than their parent peptides: (i) they showed higher hemolytic potency in acidic pH but lower lytic activity than their parent peptides in neutral pH; (ii) enhanced calcein efficiently release from both early and late endosome; (iii) they did not affect the DNA-binding affinity of BPEI and the physicochemical characteristics of BPEI/DNA complexes. Moreover, the peptides could increase BPEI-mediated transfection efficiency in different cell lines (293FT, B16F10 and CHO-K1) by simply mixing with BPEI, without causing cytotoxicity. Conclusions The results obtained in the present study indicate that the truncated peptides with higher endosomal disrupting activity were better enhancers for increasing transfection efficiency. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Protein histidine phosphorylation in eukaryotes has been sparsely studied compared to protein serine/threonine and tyrosine phosphorylation. In an attempt to rectify this by probing porcine liver cytosol with the phosphohistidine-containing peptide succinyl-Ala-His(P)-Pro-Phe-p -nitroanilide (phosphopeptide I), we observed a phosphatase activity that was insensitive towards okadaic acid and EDTA. This suggested the existence of a phosphohistidine phosphatase different from protein phosphatase 1, 2A and 2C. A 1000-fold purification to apparent homogeneity gave a 14-kDa phosphatase with a specific activity of 3 µmol·min-1 ·mg-1 at pH 7.5 with 7 µm phosphopeptide I as substrate. Partial amino-acid sequence determination of the purified porcine enzyme by MS revealed similarity with a human sequence representing a human chromosome 9 gene of hitherto unknown function. Molecular cloning from a human embryonic kidney cell cDNA-library followed by expression and purification, yielded a protein with a molecular mass of 13 700 Da, and an EDTA-insensitive phosphohistidine phosphatase activity of 9 µmol·min-1 ·mg-1 towards phosphopeptide I. No detectable activity was obtained towards a set of phosphoserine-, phosphothreonine-, and phosphotyrosine peptides. Northern blot analysis indicated that the human phosphohistidine phosphatase mRNA was present preferentially in heart and skeletal muscle. These results provide a new tool for studying eukaryotic histidine phosphorylation/dephosphorylation. [ABSTRACT FROM AUTHOR]

Viral infection triggers the formation of mitochondrial antiviral signaling protein (MAVS) aggregates, which potently promote immune signaling. Autophagy plays an important role in controlling MAVS‐mediated antiviral signaling; however, the exact molecular mechanism underlying the targeted autophagic degradation of MAVS remains unclear. Here, we investigated the mechanism by which RNF34 regulates immunity and mitophagy by targeting MAVS. RNF34 binds to MAVS in the mitochondrial compartment after viral infection and negatively regulates RIG‐I‐like receptor (RLR)‐mediated antiviral immunity. Moreover, RNF34 catalyzes the K27‐/K29‐linked ubiquitination of MAVS at Lys 297, 311, 348, and 362 Arg, which serves as a recognition signal for NDP52‐dependent autophagic degradation. Specifically, RNF34 initiates the K63‐ to K27‐linked ubiquitination transition on MAVS primarily at Lys 311, which facilitates the autophagic degradation of MAVS upon RIG‐I stimulation. Notably, RNF34 is required for the clearance of damaged mitochondria upon viral infection. Thus, we elucidated the mechanism by which RNF34‐mediated autophagic degradation of MAVS regulates the innate immune response, mitochondrial homeostasis, and infection. Synopsis: Viral infection triggers the formation of mitochondrial antiviral signaling protein (MAVS) aggregates, which potently promote immune signaling. However, the exact molecular mechanism underlying the targeted autophagic degradation of MAVS remains unclear. Here, we investigated the mechanism by which RNF34 regulates immunity and mitophagy by targeting MAVS. RNF34 negatively regulates RIG‐I like receptor (RLR)‐mediated antiviral immunity.RNF34 catalyzes the K27/K29‐linked ubiquitination of MAVS at Lys 297, 311, 348, and 362.RNF34 initiates the K63‐ to K27‐linked ubiquitination transition on MAVS primarily at Lys 311.RNF34 facilitates the autophagic degradation of MAVS.RNF34 promotes NDP52‐dependent selective mitophagy. [ABSTRACT FROM AUTHOR]

NH3 is a valuable chemical with a wide range of applications, but the conventional Haber–Bosch process for industrial‐scale NH3 production is highly energy‐intensive with serious greenhouse gas emission. Electrochemical reduction offers an environmentally benign and sustainable route to convert N2 to NH3 at ambient conditions, but its efficiency depends greatly on identifying earth‐abundant catalysts with high activity for the N2 reduction reaction. Here, it is reported that MnO particles act as a highly active catalyst for electrocatalytic hydrogenation of N2 to NH3 with excellent selectivity. In 0.1 m Na2SO4, this catalyst achieves a high Faradaic efficiency up to 8.02% and a NH3 yield of 1.11 × 10−10 mol s−1 cm−2 at −0.39 V versus reversible hydrogen electrode, with great electrochemical and structural stability. On the basis of density functional theory calculations, MnO (200) surface has a smaller adsorption energy toward N than that of H with the *N2 → *N2H transformation being the potential‐determining step in the nitrogen reduction reaction. A manganese oxide particles film on Ti mesh (MnO/TM) acts as a robust non‐noble‐metal electrocatalyst for efficient N2 reduction electrocatalysis at ambient conditions. In 0.1 m Na2SO4, the MnO/TM attains a high Faradaic efficiency up to 8.02% and a NH3 yield of 1.11 × 10−10 mol s−1 cm−2 at −0.39 V versus reversible hydrogen electrode, with high electrochemical stability. [ABSTRACT FROM AUTHOR]

A diagram explaining the construction of functionalized 1,2-Dihydropyridine and pyridine derivatives is presented.

A novel approach to construct diverse enantioenriched tricyclic heterocycles is developed using a hitherto not described asymmetric, organocatalytic allylic substitution/Diels-Alder cascade sequence. [ABSTRACT FROM AUTHOR]

NiSe2 is hydrothermally prepared from combined solutions of Se dissolved in aq. [ABSTRACT FROM AUTHOR]

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The coordination microenvironment of metal active sites in metal–organic frameworks (MOFs) plays a crucial role in its performance for electrochemical CO2 reduction reaction (CO2RR). However, it remains a challenge to clarify the structure–performance relationship for CO2RR catalyzed by MOFs. Herein, a series of MOFs with different coordination microenvironments of Cu(I) sites (CuCl, CuBr, and CuI) to evaluate their performances for CO2RR is synthesized. With the increasing radius of halogen atom, the CO2 adsorption capacity increases and d‐band center of Cu positively shifts to the Fermi level, leading to enhance the selectivity of CO2 to CH4 conversion. CuI gives the highest total Faradaic efficiency (FE) of 83.2%, with a FE of CH4 up to 57.2% and CH4 partial current density of 60.7 mA cm−2 at −1.08 V versus reversible hydrogen electrode. Theoretical calculations reveal that the shifted d‐band center of Cu site contributes to reduced formation energies of *CH2O and *CH3O intermediates, which is the potential‐determining step of CO2RR and thus facilitates the electrocatalytic CO2 reduction to CH4. This study opens a new avenue for studying the relationship between the coordination microenvironment of active site and electroreduction reaction performance of MOFs. [ABSTRACT FROM AUTHOR]