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Oxides with different crystal phases can have important effects on the configuration of surface atoms, which can further affect the distribution of hydrogenation sites and acidic sites as well as the competitions of these varied types of catalytic sites. This could be potentially used to tailor the distribution of the products. In this study, zirconium oxides with different crystal phases supported copper catalysts were prepared for the hydrogenation of the biomass-derived furfural, vanillin, etc. The results showed that both calcination temperature and Cu species affected the shift of zirconia from tetragonal phase to the monoclinic phase. Monoclinic zirconia supported copper catalyst can effectively catalyze the hydrogenation of furfural to furfuryl alcohol via hydrogenation route due to its low amount of Bronsted acidic sites, although the surface area and the exposed metallic Cu surface area were much lower than the tetragonal zirconia supported copper catalyst. Zirconia with tetragonal or tetragonal/monoclinic phases supported copper catalysts contain abundant acidic sites and especially the Bronsted acidic sites, which catalyzed mainly the conversion of furfural via the acid-catalyzed routes such as the acetalization, rather than the hydrogenation. The acidic sites over the Cu/ZrO2 catalyst played more predominant roles than the hydrogenation sites in determining the conversion of the organics like furfural and vanillin.

Two new homosioflavonoids, ophiopogonanone I (1) and methylophiopogonanone C (2) were isolated from the tuberous roots of Ophiopogon japonicus. Their structures were elucidated on the basis of extensive spectroscopic analyses. The absolute configuration of compounds 1 and 2 were assigned on the basis of CD method. In addition, compounds 1–2 were tested for their cytotoxic activities against HL-60, SMMC-7721, and MCF-7 human cancer cell lines, and compound 2 showed significant cytotoxic activity against HL-60 cell line with IC50 value of 14.42 μM.

A visible-light-induced decarboxylation reaction was developed for the synthesis of alkylated benzimidazo[2,1-a]isoquinoline-6(5H)-ones and indolo[2,1-a]isoquinolin-6(5H)-ones under metal-free conditions. Impressively, metal catalysts and traditionally volatile organic solvents could be effectively avoided.

A facile and effective approach to assemble graphene hybridized multiple manganese oxides /graphene ((m-MnO2/Gr) was explored. The structure varied from two-dimensional (2D) to one-dimensional (1D) club-shaped manganese oxides via blending of Gr into the molten salt precursor. Compared to the m-MnO2 and pristine Gr electrode, the m-MnO2/Gr composites displayed a superior synergistic effect in promoted capacitive performance, cycle performance, with capacity retention of about 90% after 2000 charge-discharge cycles. It expects to supply a promising strategy to synthesize large scalable production of hybrid supercapacitor electrode.

In order to improve the tribological behavior of Si3N4/TiC ceramics, DLC coating was fabricated on the ceramic surface through magnetron sputtering technology. The surface and cross-section micrographs, the adhesion between coating and substrate, the surface roughness and microhardness of the DLC-coated ceramics were investigated. Reciprocating friction tests sliding against cemented carbide ball were conducted under dry sliding conditions. The test results indicated that the DLC coating possessed superior tribological performance, which was conductive to decreasing the friction coefficient and enhancing the wear resistance of ceramics. The primary mechanisms responsible for performance improvement of the DLC-coated ceramics were attributed to the combined effects of low shear stress, excellent adhesion with substrate, high microhardness and good surface roughness. It was believed that the DLC coating was efficient in improving the load-carrying capacity and expanding the application area of ceramic materials.

To enhance the tribological performance of Si3N4/TiC ceramics, MoS2/PTFE composite coatings were deposited on the ceramic substrate through spraying method. The micrographs and basic properties of the MoS2/PTFE coated samples were investigated. Dry sliding friction experiments against WC/Co ball were performed with the coated ceramics and traditional ones. These results showed that the composite coatings could significantly reduce the friction coefficient of ceramics, and protect the substrate from adhesion wear. The primary tribological mechanisms of the coated ceramics were abrasive wear, coating spalling and delamination, and the tribological property was transited from slight wear to serious wear with the increase of load because of the lower surface hardness and shear strength. The possible mechanisms for the effects of MoS2/PTFE composite coatings on the friction performance of ceramics were discussed.

In this work, the conductive composites were manufactured by hot pressing with polypropylene (PP) as matrix resin and copper powder as conductive filler. The effects of copper particle radius and content on the dielectric properties of the composites were studied. The results show that dielectric constant of the composite was greatly improved than that of pure PP material. With the increase of copper content, the conductive percolating network was established within the composites. Along with the percolation phenomenon of microstructure, the conductive mechanism simultaneously changed. The absolute value of the negative permittivity also increases to 2.2 × 106. Moreover, the negative permittivity was observed by tuning their compositions and tailoring their microstructures. Further investigation revealed that there was a constitutive relationship between permittivity and reactance.

In order to study the vibration wearing regularity and the strength failure point of stator end windings before and after static rotor eccentricity, the three-dimensional electromagnetic forces and the subsequent mechanical responses are studied in this paper. The electromagnetic force, stress, and deformation on the end winding of the QFSN-600-2YHG turbo-generator are calculated by the finite element method (FEM) through an electromagnetic-structure coupling. The radial vibration characteristics of the winding are verified by experiments. It shows that the vibration wearing in the same layer is more serious than that between two neighboring layers. For different layers, the interphase coils endure a larger wearing risk than the innerphase coils. Inside the same phase, the last coil along the rotating direction has the highest risk of insulation wearing. The occurrence of static rotor eccentricity will significantly increase the electromagnetic forces and the vibration amplitudes on some coils. The end-phase coil which is close to the minimum air-gap point is the most dangerous one due to the lasting overstresses and the intensified deformations.

A general and metal-free visible-light-induced decarboxylative arylation procedure at room temperature was described for the construction of acylated heterocyclic derivatives, such as benzimidazo/indolo[2,1-a]isoquinolin-6(5H)-ones, aroylazaspiro[4.5]trienones, thioflavones, and so on. This practical arylation procedure was conducted by using 2,4,5,6-tetra(9H-carbazol-9-yl)isophthalonitrile (4CzIPN) as a photocatalyst under mild conditions, which avoided the use of an additional base, traditional heating, and metal reagents.

Two new alkaloids, phranisines A–B (1–2), along with two known compounds, N-p-Coumaroyl serotonin (3) and N-p-coumaroyl-tryptamine (4), were isolated from the roots of Phragmites australis. The structures of 1–4 were established on the basis of extensive spectroscopic. The absolute configuration of compounds 1–2 were identified through quantum-chemical electronic circular dichroism (ECD) calculation compared with their experimental CD. All the isolated compounds were tested for their cytotoxic activities against HeLa and MCF-7 human cancer cell lines, and compounds 2–4 showed moderate cytotoxic activities against HeLa cell lines with IC50 values ranging from 13.2 to 18.6 μM.

Plants establish symbioses with mutualistic fungi, such as arbuscular mycorrhizal (AM) fungi, and bacteria, such as rhizobia, to exchange key nutrients and thrive. Plants and symbionts have coevolved and represent vital components of terrestrial ecosystems. Plants employ an ancestral AM signaling pathway to establish intracellular symbioses, including the legume–rhizobia symbiosis, in their roots. Nevertheless, the relationship between the AM and rhizobial symbioses in native soil is poorly understood. Here, we examined how these distinct symbioses affect root-associated bacterial communities in Medicago truncatula by performing quantitative microbiota profiling (QMP) of 16S rRNA genes. We found that M. truncatula mutants that cannot establish AM or rhizobia symbiosis have an altered microbial load (quantitative abundance) in the rhizosphere and roots, and in particular that AM symbiosis is required to assemble a normal quantitative root-associated microbiota in native soil. Moreover, quantitative microbial co-abundance network analyses revealed that AM symbiosis affects Rhizobiales hubs among plant microbiota and benefits the plant holobiont. Through QMP of rhizobial rpoB and AM fungal SSU rRNA genes, we revealed a new layer of interaction whereby AM symbiosis promotes rhizobia accumulation in the rhizosphere of M. truncatula. We further showed that AM symbiosis-conditioned microbial communities within the M. truncatula rhizosphere could promote nodulation in different legume plants in native soil. Given that the AM and rhizobial symbioses are critical for crop growth, our findings might inform strategies to improve agricultural management. Moreover, our work sheds light on the co-evolution of these intracellular symbioses during plant adaptation to native soil conditions.

Rice grains typically contain high levels of toxic arsenic but low levels of the essential micronutrient selenium. Anthropogenic arsenic contamination of paddy soils exacerbates arsenic toxicity in rice crops resulting in substantial yield losses. Here, we report the identification of the gain-of-function arsenite tolerant 1 (astol1) mutant of rice that benefits from enhanced sulfur and selenium assimilation, arsenic tolerance, and decreased arsenic accumulation in grains. The astol1 mutation promotes the physical interaction of the chloroplast-localized O-acetylserine (thiol) lyase protein with its interaction partner serine-acetyltransferase in the cysteine synthase complex. Activation of the serine-acetyltransferase in this complex promotes the uptake of sulfate and selenium and enhances the production of cysteine, glutathione, and phytochelatins, resulting in increased tolerance and decreased translocation of arsenic to grains. Our findings uncover the pivotal sensing-function of the cysteine synthase complex in plastids for optimizing stress resilience and grain quality by regulating a fundamental macronutrient assimilation pathway., Contamination of paddy soils can lead to toxic arsenic accumulation in rice grains and low levels of the micronutrient selenium. Here the authors show that a gain of function mutant affecting an O-acetylserine (thiol) lyase enhances sulfur and selenium assimilation while reducing arsenic accumulation in grains.

Sparse representation (SR)-based pansharpening methods which combine the dictionary and estimated sparse coefficients have achieved visually and quantitatively great results in pansharpening proble...

Isolation and analysis of circulating rare cells is a promising approach for early detection of cancer and other diseases and for prenatal diagnosis. Isolation of rare cells is usually difficult due to their heterogeneity as well as their low abundance in peripheral blood. We previously reported a two-stage ensemble-decision aliquot ranking platform (S-eDAR) for isolating circulating tumor cells from whole blood with high throughput, high recovery rate (>90%), and good purity (>70%), allowing detection of low surface antigen-expressing cancer cells linked to metastasis. However, due to the scarcity of these cells, large sample volumes and large quantities of antibodies were required to isolate sufficient cells for downstream analysis. Here, we drastically increased the number of nucleated cells analyzed by first concentrating peripheral blood mononuclear cells (PBMCs) from whole blood by density gradient centrifugation. The S-eDAR platform was capable of isolating rare cells from concentrated PBMCs (108/mL, equivalent to processing ~20 mL of whole blood in the 1 mL sample volume used by our instrument) at a high recovery rate (>85%). We then applied the S-eDAR platform for isolating rare fetal nucleated red blood cells (fNRBCs) from concentrated PBMCs spiked with umbilical cord blood cells and confirmed fNRBC recovery by immunostaining and fluorescence in situ hybridization, demonstrating the potential of the S-eDAR system for isolating rare fetal cells from maternal PBMCs to improve noninvasive prenatal diagnosis.

Polymerization is a major challenge for the upgrading of bio-oil to biofuels, but is preferable for the production of carbon material from bio-oil. Understanding the mechanism for polymerization is of importance for tailoring property of carbon material. This study investigated the characteristics for the polymerisation of furfural, vanillin, their cross-polymerization and the impacts of catalysts on their polymerization. The results indicated that the organic acids like acetic acid and formic acid could catalyze the polymerisation of furfural, while H2SO4 or NaOH as catalyst could drastically enhance the degree of polymerization of furfural. Vanillin showed a higher tendency towards polymerization than furfural and H2SO4 or NaOH significantly facilitated the polymerization of vanillin via shifting the pasty product to solid polymer. The cross-polymerization between furfural and vanillin occurred even in the absence of catalyst, while the presence of H2SO4 or NaOH catalyst resulted in the formation of more solid polymer via cross-polymerization. The polymerisation reactions were accompanied with the consumption of –C=O via aldol addition/condensation reactions. In addition, the morphology and thermal stability of the polymers formed were affected by both the type of the catalysts employed, which can in turn enhance the cross-polymerization between furfural and vanillin.

The root endophyte Phomopsis liquidambaris B3 effectively protected peanut against root rot caused by Fusarium oxysporum. We investigated (i) the effects of preinoculation (before F. oxysporum inoculation) and postinoculation (post F. oxysporum inoculation) with B3 on pathogenic infection and (ii) the potential mechanisms underlying the suppression of root rot by B3 colonization. Peanut seedlings preinoculated, postinoculated or noninoculated with B3 and challenged or not challenged with F. oxysporum were cultivated in pots with sterilized vermiculite. The root rot severity, plant growth, defense-related enzyme activity and signaling compounds in plant tissues were investigated. Chemical manipulation experiments were performed to verify the signals involved in the suppression of root rot by B3. B3 preinoculation efficiently suppressed root rot, as evidenced by decreased cell death, pathogenic colonization and disease severity; however, these effects were absent in the B3 posttreated roots. B3 preinoculation locally and systemically enhanced resistance against pathogenic infection, which coincided with increased activities of pathogenesis-related proteins. These increased activities positively correlated with increased salicylic acid (SA) and hydrogen peroxide (H2O2) levels, in which SA played a dominant role. Preinoculation with B3 effectively suppressed F. oxysporum infection in peanut roots by activating the SA-dependent defense pathway.

Manganese zinc (Mn-Zn) ferrites were prepared by solid-state reaction. The sintering process was investigated in detail using differential scanning calorimetry/thermogravimetric analysis and x-ray diffraction characterizations. A three-step weight loss was observed and the main Mn-Zn ferrite formation reaction was detected. Two-step heat treatment was employed to achieve high density Mn-Zn ferrite. For sintering temperatures from 1300°C to 1400°C, crystal grains of Mn-Zn ferrite became uniform with larger size and more equiaxed shape. The grain boundaries changed from curved to straight. Such features were believed helpful for the magnetic domain wall movement. In addition, better diffusivity at higher sintering temperature homogenized the distribution of impurities which also facilitated the magnetic domain alignment. Thanks to the microstructure acquired by controlling the sintering process, a high-amplitude permeability of 1151, a low total loss of 411 W/kg and coercivity of 57.63 A/m at 65 kHz were simultaneously achieved on samples sintered at 1400°C.

The hierarchical Bi/Mo/bismuth molybdate (Bi–Mo–BMO) hollow composite nanospheres were prepared by simple two-step reaction. Compared with pure Bi2MoO6, the depositing of Bi small nanosheets and Mo nanoparticles reduces the bandgap to 2.08 eV and enhances the absorption of visible light. Moreover, the unique structure and composition of Bi–Mo–BMO can offer abundant catalytic sites and large surface area and boost the separation and transfer of carriers. Benefiting from these favorable properties, the Bi–Mo–BMO nanocomposites exhibit a higher photocatalytic reduction ability of rhodamine B (RhB) than pure Bi2MoO6. In particular, the optimized Bi–Mo–BMO exhibits the highest photocatalytic activity, and RhB can be degraded by 97% within 10 min, which is about 122 times that of pure Bi2MoO6. After eight cycles, Bi–Mo–BMO still maintains the original photocatalytic activity, indicating its excellent stability and repeatability. Based on the experimental results, the possible photocatalytic mechanism of Bi–Mo–BMO is proposed.

Ni–Al hydrotalcite-like compounds (Ni–Al HTLCs) containing nitrate anions were synthesized and applied in the acetalization of p-anisaldehyde with ethylene glycol under mild reaction conditions. The Ni–Al HTLCs showed good selectivity for acetalization and achieved almost complete conversion of p-anisaldehyde. The Ni–Al HTLCs as water-tolerant Lewis acids were proved to be an efficient and recyclable catalyst for the acetalization. The oxygen vacancies play an important role in the catalytic activity of Lewis acidic sites on the surface of Ni–Al HTLCs. The NO3− anions coordinate to the matrix Ni2+ cations through oxygen atoms to form [Ni(OH)5NO3] units in the distorted octahedral crystal field, and the most oxygen vacancies in freshly-prepared Ni–Al HTLCs result from the strongly distorted [Ni(OH)5NO3] units. The gradual conversion of distorted [Ni(OH)5NO3] units into regular [Ni(OH)6] units will lead to a loss in catalytic activity of Ni–Al HTLCs.

Photocatalytic nitrogen fixation performance is mainly hampered by slow carrier transport and inefficient surface reaction, where surface oxygen vacancies have been proved to alleviate these limitations. However, there are a few reports on the introduction of metal vacancies into photocatalysts and the effect of metal vacancies on the N2 photofixing properties. Herein, we injected bismuth vacancies (VBi) into the surface of BiOBr nanospheres with oxygen vacancies (VO) via an ion exchange strategy to form hierarchical Bi2MoO6/BiOBr composite structures. The intentionally introduced VBi adjust the band structures of VO–BiOBr and act as charge separation centers in coordination with VO, which improves the separation efficiency of electron–hole pairs. The presence of VBi and the Bi2MoO6 phase enhances the light absorption of the composite materials. Additionally, the hierarchical nanosheet assembly structure facilitates the surface adsorption and activation of N2 on the catalyst. In particular, the optimal defect-rich Bi2MoO6/VBi+O–BiOBr exhibits the best photocatalytic ammonia production activity. After two hours, the NH3 yield was 412.18 mol L−1 without any noble metal cocatalyst and sacrificial agent, and was nearly 4 times higher than that of the original VO–BiOBr (96.08 mol L−1). This work provides a new inspiration for the design of efficient N2 immobilizing photocatalysts through synergistic metal and oxygen vacancy engineering.

Negative permittivity has been widely studied in various metamaterials and percolating composites, of which the anomalous dielectric behavior was attributed to critical structural properties of building blocks. Herein, mono-phase ceramics of indium tin oxides (ITO) were sintered for epsilon-negative materials in MHz-kHz frequency regions. Electrical conductivity and complex permittivity were analyzed with Drude-Lorentz oscillator model. Carriers’ characters were measured based on Hall effect and the magnitude and frequency dispersion of negative permittivity were mainly determined by carrier concentration. Temperature-dependent dielectric properties further proved the epsilon-negative behaviors were closely associated with free carriers’ collective responses. It’s found that negative permittivity of ITO ceramics was mainly caused by plasma oscillations of free carriers, while the dielectric loss was mainly attributed to conduction loss. Negative permittivity realized here was related to materials intrinsic nature and this work preliminarily determined the mechanism of negative permittivity in doped ceramics from the perspective of carriers.

The interfacial structures of C60 molecules adsorbed on solid surfaces are essential for a wide range of scientific and technological processes in carbon-based nanodevices. Here, we report structural transitions of the C60 monolayer on the Bi(111) surface studied via low-temperature scanning tunneling microscopy (STM). With an increase in temperature, the structure of the C60 monolayer transforms from local-order structures to a (√93 × √93) R20° superstructure, and then to a (11 × 11) R0° superstructure. Moreover, the individual C60 molecules in different superstructures have different orientations. C60 molecules adopt the 6 : 6 C–C bond and 5 : 6 C–C bond facing-up, mixed orientations, and hexagon facing-up in the local-order structure, (√93 × √93) R20°, and (11 × 11) R0° superstructure, respectively. These results shed important light on the growth mechanism of C60 molecules on solid surfaces.

A metal-free and base-free procedure for the phosphorylation of imidazo[1,2-a]pyridines with phosphine oxides under the irradiation of visible light at room temperature in green solvent was reported, featuring mild and sustainable conditions, convenient operation, as well as good functional group compatibility.

Radio frequency (RF) magnetron sputtering was used to fabricate Cu-doped Cu2O thin using a gas mixture containing 80% Ar and 20% N2 at room temperature. The Cu2O ceramics containing different concentrations of Cu powder (1–7 wt%) were considered to be the sputtering targets. A highly dense Cu-doped Cu2O target was essential to obtain excellent quality Cu2O films; this target can be obtained via the hot-pressing process because the low melting point (1084.6 °C) of Cu allows enhanced densification of the Cu2O target through a liquid-phase wetting mechanism. X-ray diffraction (XRD), Raman spectroscopy, field emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM) were performed to characterize the Cu2O film microstructure. Our results denoted that Cu doping enhances the densification and increases the grain size of the Cu2O films. Further, the crystal structures of the films changed from CuO and Cu4O3 to Cu2O when the Cu doping concentration increased from 1 to 7 wt%. A dense and well-defined columnar morphology can be observed when TEM was used to observe the film microstructure. Subsequently, the electrical and optical properties of the Cu2O thin films were evaluated at different Cu concentrations. The electrical resistivity of the Cu2O films became 8.6 Ω·cm when the Cu doping concentration was 7 wt%, corresponding to a carrier density of 9.8 × 1016 cm−3 and a mobility of 7.5 cm2/Vs. Furthermore, the optical transmission of the Cu2O films doped with Cu was greater than 60%. The band gaps of the films ranged from 2.32 to 2.54 eV depending on the copper oxide phases present in the films.

The e-negative property in metacomposites has triggered tremendous interest in electromagnetic fields. In this work, a tunable and weakly e-negative property was obtained in graphene–carbon black/C...

Non-precious metal-nitrogen-carbon (MNC) electrocatalysts have gained tremendous attention as promising electrocatalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). However, the most applicable strategies for the synthesis of MNC materials heavily rely on pyrolysis treatment, which may easily lead to metal aggregation and subsequent degradation of catalytic performance. Herein, we developed a pyrolysis-free strategy for preparing MNC materials, which was demonstrated by achieving ultrathin cobalt-nitrogen-carbon (CoNC) layer with dense atomically dispersed cobalt sites depositing on graphene oxide (GO) via simple treatment of Co salt and GO in formamide. The formamide-derived CoNC layer deposited on GO (termed as f-CoNC/GO) could be controlled in 1‒2 nm thick. Remarkably, the f-CoNC/GO composite without pyrolysis exhibited excellent bifunctional performance toward ORR and OER, which was attributed to the dense atomically dispersed Co-Nx sites and improved conductivity by GO substrate. Furthermore, the f-CoNC/GO-assembled rechargeable Zn-air battery showed highly efficient and stable performance, demonstrating our pyrolysis-free method to be straightforward, cost-effective, and feasible for the scalable production of MNC electrocatalysts.

Exciton dynamics can be strongly affected by lattice vibrations through electron-phonon coupling. This is rarely explored in two-dimensional magnetic semiconductors. Focusing on bilayer CrI3, we first show the presence of strong electron-phonon coupling through temperature-dependent photoluminescence and absorption spectroscopy. We then report the observation of periodic broad modes up to the 8th order in Raman spectra, attributed to the polaronic character of excitons. We establish that this polaronic character is dominated by the coupling between the charge-transfer exciton at 1.96 eV and a longitudinal optical phonon at 120.6 cm-1. We further show that the emergence of long-range magnetic order enhances the electron-phonon coupling strength by about 50$\%$ and that the transition from layered antiferromagnetic to ferromagnetic order tunes the spectral intensity of the periodic broad modes, suggesting a strong coupling among the lattice, charge and spin in two-dimensional CrI3. Our study opens opportunities for tailoring light-matter interactions in two-dimensional magnetic semiconductors., Comment: 21 pages, 4 figures + Supplementary Information

A feasible arylaminomethyl radical-triggered tandem annulation reaction has been developed toward a large variety of poly fused heterocycles, tetrahydroimidazo[1,5-a]quinoxalin-4(5H)-ones, by reacting diverse quinoxalin-2(1H)-ones with various N-arylglycines in green solvent (DMC) in the presence of CsPbBr3 under white-light irradiation conditions.

Background Seed germination and young seedling growth are important agricultural traits for developing populations of both irrigated and directly seeded rice. Previous studies have focused on the identification of QTLs. However, there are few studies on the metabolome or transcriptome of germination and young seedling growth in rice. Results Here, an indica rice and a japonica rice were used as materials, and the transcripts and metabolites were detected during the germination and young seedling growth periods on a large scale by using RNA sequencing and a widely targeted metabolomics method, respectively. Fourteen shared transcripts and 15 shared metabolites that were continuously differentially expressed in the two materials were identified and may be essential for seed germination and young seedling growth. Enrichment analysis of differentially expressed genes in transcriptome expression profiles at different stages indicated that cell wall metabolism, lipid metabolism, nucleotide degradation, amino acid, etc., were enriched at 0–2 days, and most of the results are consistent with those of previous reports. Specifically, phenylpropanoid biosynthesis and glutathione metabolism were continuously enriched during the seed germination and young seedling growth stages. Next, KO enrichment analysis was conducted by using the differentially expressed genes of the two materials at 2, 3 and 4 days. Fourteen pathways were enriched. Additionally, 44 differentially expressed metabolites at 2, 3 and 4 days were identified. These metabolites may be responsible for the differences in germination and young seedling growth between the two materials. Further attention was focused on the ascorbate–glutathione pathway, and it was found that differences in ROS-scavenging abilities mediated by some APX, GPX and GST genes may be directly involved in mediating differences in the germination and young seedling growth speed of the two materials. Conclusions In summary, these results may enhance the understanding of the overall mechanism of seed germination and young seedling growth, and the outcome of this study is expected to facilitate rice breeding for direct seeding.

Combination therapy with multiple drugs through a multi-pronged assault as a strategy to combat cisplatin resistance shows great potential in biochemical therapy for cancer. However, inherent issues such as low drug loading and the poor synergistic effects of multiple drugs partially limit the further application of combination therapy. Here, we synthesized a new compound, ART-Chol, by coupling artemisinin and cholesterol as a base material combined with cyclic (Arg-Gly-Asp-d-Phe-Lys)]-poly(ethylene glycol) distearoylphosphatidylcholine (cRGD-PEG-DSPE) and phospholipids to form a magnetic liposome cRGD-AFePt@NPs encapsulating superparamagnetic ferric oxide nanoparticles and cisplatin for achieving high drug loading and a better synergistic effect. The cRGD-AFePt@NPs could be effectively internalized and responsively release loading cargos under alternating magnetic field irradiation due to local hyperthermia generated from magnetic nanoparticles by hysteresis loss and Neel relaxation. The generated Fe2+/F...

Seven new 4-acyl-2-aminoimidazoles, designated strepimidazoles A-G (1-7), were discovered from the endophytic Streptomyces sp. PKU-EA00015 isolated from Salvia miltiorrhiza Bunge, whose dry root "Danshen" is one of the most widely used traditional Chinese medicines. The resonance signals of the 2-aminoimidazole moiety in 1-7 were absent in the NMR spectra due to tautomerization, and the structures of 1-7 were identified after preparation of their acetylation products 1a-7a, respectively. Compounds 1-7 represent a new family of 2-aminoimidazole-containing natural products, enriching the structural diversity of natural products from endophytic origin. Compounds 1-7 showed different degrees of inhibitory activities against the plant pathogenic fungus Verticillium dahliae V991, revealing structure-activity relationships on the acyl moieties. The plant pathogenic fungus V. dahliae has been confirmed to cause serious chlorosis of cultivated S. miltiorrhiza Bunge in China. This study opens the door for further investigation of mutualistic relationships between S. miltiorrhiza Bunge and their endophytic actinomycetes and for possible antifungal agent development for biological control of V. dahliae in the future.

Solid polymer electrolyte (SPE) is one of the choices for many ionic devices, including organic transistors, ion batteries, memristors, and more. However, uncontrollable conductive filament formation seriously affects the performance of the device. In this paper, the PEDOT:PSS was doped to improve the electronic and ionic conductivity of amorphous polymer electrolyte poly(vinylpyrrolidone) (PVP), realizing the transition of the filaments growth from cathode to anode in atomic switch memristors. Based on the difference in ion and electron mobility and scanning electron microscope observation, the in situ reductions of metal ions inside the dielectric layer can effectively prevent the formation of uncontrollable filaments. The formation of uniformly distributed metal particles in the dielectric layer is similar to co-sputter doping technology, which enables the device to exhibit excellent performance, such as smaller set/reset bias distribution, endurance, and retention. Obviously, this innovative way improves the conductive mechanism of ionic devices.

“Zero-strain” Li4Ti5O12 has become one of the most promising anode materials for lithium-ion battery but its low electronic and ionic conductivity lead to the poor rate capability. Herein, the high-rate performance and the cycling stability of Li4Ti5O12 have been largely enhanced by replacing Li and Ti with a little amount of Mg and La, respectively. The synergistic modulation mechanism of Mg and La co-doping on the crystal/electronic structure and electrochemical performances has been unveiled. Firstly, Mg and La co-doping enlarges the lattice parameters, unit cell volume and Li1–O bond. These facilitate the lithium-ion migration and enhance the rate capability. Secondly, Ti–O bond is shortened which enhances the structure stability and cyclic performance. Thirdly, the first-principles calculations further confirm that Mg/La co-doping modulates the electronic density of states and decreases the Li+ migration barrier. The polarization and charge transfer impedance are effectively alleviated. Moreover, the diffusion coefficient of lithium ions is further improved because of the reduction of much more Ti3+. At 10C, it delivers a discharge capacity of 107.8mAh/g after 500cyles which reserves 92.2% of the initial capacity. This study provides some insights into optimizing the electrochemical performances of Li4Ti5O12 by tuning the crystal and electronic structure with lattice doping.

Nano-sized α-Al2O3 ceramic-particle-reinforced molybdenum alloy plates were fabricated by a series of processes including hydrothermal synthesis, powder metallurgy, and rolling. The quantitative effect of α-Al2O3 ceramic (particle size and volume fraction) on the microstructures and mechanical properties of molybdenum alloy plates was investigated. Nano-sized α-Al2O3 ceramic particles were obtained and uniformly dispersed in the molybdenum matrix. The α-Al2O3 ceramic refined the molybdenum grains and remarkably increased the microhardness, elastic modulus, and yield strength. The yield strength of the alloy reached a peak value when the α-Al2O3 ceramic content was 1.28 vol% and increased by 61.07%–90.2% compared with that of pure molybdenum after annealing at 1000 °C-1300 °C. A quantitative yield strength model correlating α-Al2O3 particle size, α-Al2O3 volume fraction, molybdenum grain size, and annealing temperature was built. This model attributes the strengthening of alloy to the synergy effects of grain refinement strengthening (σHP) and Orowan strengthening (σp). The addition of fine α-Al2O3 ceramic resulted in Orowan strengthening and fine molybdenum grains, thereby increasing yield strength of alloy.

Accurate contact calculations of real rough surfaces are fundamental but complicated. The model-based methods are convenient and straightforward. But these methods ignore some factors and may lead to less accurate results. This is especially true when considering multi-scale topographic features of engineering rough surfaces. Based on artificially generated rough surfaces, the deterministic contact analysis of two 3D rough surfaces is conducted by the finite element method (FEM). The calculations show that when the separation between surfaces reduces, results of classic model-based methods are quite different from those of this study, especially when the roughness distribution and textures are considered. As friction pairs are working under increasing harsh conditions, the accurate contact calculation in this paper will be of great significance.

The anionic redox chemistry (O2−→O−) in P2-type sodium-ion battery cathodes has attracted much attention. However, determining how to tune the anionic redox reaction is still a major challenge. Herein, we tune the activity and reversibility of both the anionic and cationic redox reactions of Na0.67Mn0.5Fe0.5O2 though an integrated strategy that combines the advantages of Li2SiO3 coating, Li doping and Si doping, and the initial capacity, rate performance and cycling stability are significantly improved. The in-depth modulation mechanism is revealed by means of neutron diffraction, X-ray absorption spectroscopy, in situ X-ray diffraction, electron paramagnetic resonance spectroscopy, first-principles calculations and so on. The Li2SiO3 coating alleviates the side reactions and enhances the cycling stability. Si4+ doping lowers the Na+ diffusion barrier due to the expanded interlayer spacing. Additionally, Si4+ doping improves the structural stability, oxygen redox activity and reversibility. Li+ doping in Na sites further increases the structure stability. The electron density maps confirm the greater activity of Na and O in the modified sample. Nuclear density maps and bond-valence energy landscapes identify the Na+ migration pathway from Nae site to Naf site (the positions of the Na ions in the crystal structure). The proposed insights into the modulation mechanism of the anionic and cationic redox chemistry are also instructive for designing other oxide-based cathode materials.

BACKGROUND: The synthesis of solid acid catalysts of recoverable and environmentally friendly nature has gained increasing attention in recent years. The distribution of Bronsted and Lewis acidic sites on the surface of sulfated metal oxides determines the catalytic performance, which is affected by many key factors, such as the concentration of sulfuric acid impregnated and the morphology of the metal oxides used. In this study, TiO₂ nanosheets were successfully synthesized and used as carrier for the preparation of solid acid catalysts. RESULTS: The concentration of sulfuric acid for the impregnation resulted in various distributions of Bronsted and Lewis acidic sites on the surface of sulfated TiO₂. With a medium concentration of sulfuric acid (1 mol L⁻¹) for the impregnation, the highest ratio of Bronsted to Lewis acidic sites can be achieved, and the catalyst showed superior catalytic activity for the conversion of furfuryl alcohol (FA) to ethyl levulinate (EL) in ethanol and the conversion of fructose to 5‐hydroxymethylfurfural (HMF) in dimethyl sulfoxide (DMSO). CONCLUSION: The sulfation of TiO₂ nanosheets induced the formation of both Bronsted and Lewis acidic sites. The Bronsted acidic sites were more effective for catalyzing the conversion of FA or fructose. The poor recyclability of the 1.0‐SO₄²⁻/TiO₂ catalyst in the conversion of FA to EL in ethanol, a protic solvent, was due to the leaching of sulfur species. The deactivation of the catalyst in DMSO was due to coking, which could be resolved via calcination of the coke species in air. © 2019 Society of Chemical Industry

Simultaneous H, He and Fe ion beam irradiations were conducted on a pyrolytic carbon (PyC) - SiCf/SiC composite at 475 °C with the peak displacement damage level up to 47 dpa and concentrations of He and H up to 38 and 3400 appm, What respectively. Cross-sectional transmission electron microscopy was used to study the evolution of microstructure after the triple beam irradiation. Results show that the interface between SiC fiber and PyC interphase cracked after the triple ion beam irradiation. The PyC interphase could infiltrate into the multilayer SiC coating to cause deformation of the multilayer due to volume expansion. After irradiation, no obvious cavities were observed in multilayer SiC coating and SiC matrix, while He bubbles as large as 15 nm in diameters were observed at the peak displacement damage region in the SiC fiber and SiC coating/PyC interface. Hydrogen promotes nucleation and growth of He bubbles by reducing their surface energy. The formation process of cavities at the interface between PyC interphase and multilayer SiC coating is discussed.

The spin dynamics of {Cr8Y8}, a rare example of ferromagnetic molecular rings, has been studied by inelastic neutron scattering (INS) and heat capacity (HC) methods. Clear evidence of low-lying magnetic excitation has been found. Magnetic Schottky anomalies are observed in low-temperature (low-T) HC curves measured under various fields and can be well fitted with a multi-level Schottky term, giving important information on the energy gaps between spin levels. The INS results obtained on TOFTOF and NEAT time-of-flight spectrometers show INS peaks corresponding to the transitions within S = 12 ground states and between the S = 12 ground state and the S = 11 excited state. The single-J model with a unique exchange constant J = 0.151 meV can well reproduce the low-lying energy levels and their Zeeman splitting upon applied magnetic fields. This work shows that the single-J model can be a good approach for the low-T spin dynamics of {Cr8Y8} and may have general significance for other weak ferromagnetic molecular rings. Determination of the Cr3+-Cr3+ exchange constant in {Cr8Y8} will benefit the study on the complicated magnetic interactions in chromium lanthanide complexes. The zero-field splitting which is suggested by HC data still calls for EPR or high-resolution INS technique to verify.

Materials with negative permittivity need to be used at different temperatures, while the negative permittivity behavior affected by large fluctuations in temperature has seldom been studied. In this work, La0.5Sr0.5MnO3 ceramics were prepared by a sol-gel auto-combustion method and subsequent sintering. The negative permittivity behavior, electrical conductivity and reactance of La0.5Sr0.5MnO3 ceramics were systematically studied at various temperatures. The fluctuation in negative permittivity is less than 2.6 % and the dielectric loss (tanδ) is less than 0.2 in the temperature range of 50–600 °C. Based on the key governing properties being achieved, the present work experimentally demonstrates that La0.5Sr0.5MnO3 ceramics, as single-phase oxides, can be used as a feasible alternative metamaterial in a wide temperature range.

Different stresses can occur in the carbon cathodes due to melting and penetration of sodium during aluminum electrolysis. Under high temperatures and elevated stress, carbon blocks experience primary creep, which can be extended to the secondary and tertiary creep stages. It is quite necessary to characterize the creep behavior of carbon cathodes. Therefore, uniaxial compressive creep testing devices have been used for measuring the creep strain of a semi-graphitic cathode material during aluminum electrolysis under various stress levels. The Graham creep equation is applied for the evaluation of the creep curves and the relationship between creep coefficient and stress is determined. The creep properties of carbon cathode are obtained via numerical simulation. The extracted model effectively supports the obtained experimental results. This work introduces a new insight into the development of cell design and quality control of carbon cathode materials.

In this work, the insulating SiO2 was coated successfully on the surface of reduced iron particles by a sol-gel method to decrease the core loss at low frequency. The scanning electron microscope images and elements analysis confirm that the surface of iron powders particles were covered by a thin insulating layer in the form of uniform core-shell structure. The samples were annealed at 400 °C in N2 atmosphere to obtain better magnetic properties. The annealed SMCs with 10 mL/h dropping rate of TEOS have optimum magnetic properties with low core loss Ps of 280.89 W/kg and high saturation magnetic flux density Bs of 1.038 T at 1000 Hz.

Soil-borne pathogens severely reduce the agricultural yield of peanuts. Accordingly, the application of biocontrol agents for plant disease management is a potentially powerful method for peanut cultivation. This study aimed to (1) evaluate the protective effect of the fungal endophyte Phomopsis liquidambaris for peanut plants against leaf spot disease caused by Colletotrichum gloeosporioides and against root rot disease caused by Fusarium oxysporum under outdoor conditions and (2) explore the potential biological control mechanisms of P. liquidambaris under greenhouse conditions. In our outdoor pot experiments, P. liquidambaris significantly reduced leaf spot and root rot diseases while increasing peanut yields. Under greenhouse conditions, P. liquidambaris–induced resistance against pathogens was associated with increased antioxidant enzyme activity, callose deposition, cell lignification, and phytoalexins accumulation. The demonstrated ability of P. liquidambaris to control disease makes it a strong biocontrol agent candidate.

In this work, we designed and fabricated Pd/Au bimetallic thin film electrodes with isolated Pd nanoparticles via underpotential deposition of copper on a gold substrate followed by in situ redox replace reaction in a Pd salt solution. The Pd/Au electrode was characterized by AFM and XPS as well as multiple electrochemical techniques including CV and electrochemical quartz crystal microbalance (EQCM) in sulfuric acid and phosphate buffer electrolytes. Results show that the reduction reactions of the analytes (i.e., H

Evolution of microstructure and nanohardness of a new type of SiCf/SiC composite under a 6 MeV Au ion irradiation up to 90 displacements per atom at 400 °C was studied. Scanning transmission electron microscopy reveals that the irradiation has induced enrichment of carbon at the grain boundaries in the fibers. This is attributed to the accumulation of C interstitials generated by the irradiation. The disappearance of {200} diffraction ring of 3C–SiC indicates that a phase transition from 3C–SiC to Si has occurred during irradiation. In addition, the hardness of SiC fiber increased after irradiation, which is due to the pinning effect caused by irradiation-induced defects. The pyrolytic-carbon interphase that contains Si-rich nano-grains in the composite has the highest irradiation tolerance as it maintained its basic morphology and graphitic nature after a radiation damage dose up to 90 dpa. Twins are the main internal defects in the SiC matrix of the SiCf/SiC composite, which grew up and resulted in the decrease of the number of twinning boundaries under irradiation. No significant microstructure change has been observed in the SiC matrix except a limited number of dislocation loops at the peak irradiation damage region. The entire matrix still maintained its hardness after irradiation.

The influence of barium addition to a Ni/Al2O3 catalyst on the reaction intermediates formed, the activity, resistance of the catalyst to coking, and properties of the coke formed after acetic acid steam reforming were investigated in this study. The results showed the drastic effects of barium addition on the physicochemical properties and performances of the catalyst. The solid-phase reaction between alumina and BaO formed BaAl2O4, which re-constructed the alumina structure, resulting in a decrease in the specific surface area and an increase in the resistance of metallic Ni to sintering. The addition of barium was also beneficial for enhancing the catalytic activity, resulting from the changed catalytic reaction network. The in-situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) study of the acetic acid steam reforming indicated that barium could effectively suppress the accumulation of the reaction intermediates of carbonyl, formate, and C=C functional groups on the catalyst surface, attributed to its relatively high ability to cause the gasification of these species. In addition, coking was considerably more significant over the Ba–Ni/Al2O3 catalyst. Moreover, the Ba–Ni/Al2O3 catalyst was more stable than the Ni/Al2O3 catalyst, owing to the distinct forms of coke formed (carbon nanotube form over the Ba–Ni/Al2O3 catalyst, and the amorphous form over the Ni/Al2O3 catalyst).

Selectively hydrogenating the carbonyl of furfural and opening of the furan ring is challenging while crucial for efficient conversion of furfural to pentanediols, the valuable chemicals. In this s...

Arsenic (As) contamination in paddy soil can cause phytotoxicity and elevated As accumulation in rice grains. Arsenic detoxification is closely linked to sulfur assimilation, but the genes involved have not been described in rice. In this study, we characterize the function of OASTL-A1, an O-acetylserine(thiol) lyase, in cysteine biosynthesis and detoxification of As in rice. Tissue expression analysis revealed that OsOASTL-A1 is mainly expressed in roots at the vegetative growth stage and in nodes at the reproductive stage. Furthermore, the expression of OsOASTL-A1 in roots was strongly induced by As exposure. Transgenic rice plants expressing pOsOASTL-A1::GUS (β-glucuronidase) indicated that OsOASTL-A1 was strongly expressed in the outer cortex and the vascular cylinder in the root mature zone. Subcellular localization using OsOASTL-A1:eGFP (enhanced green fluorescent protein) fusion protein showed that OsOASTL-A1 was localized to the cytosol. In vivo and in vitro enzyme activity assays showed that OsOASTL-A1 possessed the O-acetylserine(thiol) lyase activity. Knockout of OsOASTL-A1 led to significantly lower levels of cysteine, glutathione, and phytochelatins in roots and increased sensitivity to arsenate stress. Furthermore, the osoastl-a1 knockout mutants reduced As accumulation in the roots, but increased As accumulation in shoots. We conclude that OsOASTL-A1 is the cytosolic O-acetylserine(thiol) lyase that plays an important role in non-protein thiol biosynthesis in roots for As detoxification.

s: Epsilon-negative materials with high thermal conductivity and low electrical conductivity are of great importance for high power microwave devices. In this work, BaTiO3/Cu composites, as a class of epsilon-negative materials, are rationally designed to achieve a high thermal conductivity yet maintaining the electrical insulative character. Negative permittivity behavior induced by dielectric resonance and plasma oscillation is observed in these BaTiO3/Cu composites, which can be explained by the Lorentz and Drude model respectively. An outstanding absorption ability is achieved near the zero-cross point of the permittivity. Benefiting from the positive temperature coefficient of resistance and the weak temperature dependence of thermal conductivity in BaTiO3/Cu composites, sample containing 22.3 vol% of Cu content exhibits a thermal conductivity of up to 17.7 W/(m·k) and an electrical conductivity down to 0.0022 (Ω cm)−1 at 150 °C. Therefore, BaTiO3/Cu composite is a promising candidate for applications in electromagnetic attenuation and thermal management. Keywords: BaTiO3/Cu composite, Negative permittivity, Percolation, Thermal conductivity, Electrical conductivity

In this paper, we present an open python procedure with Jupyter notebook, for data extraction and vectorization of geophysical exploration profile. Constrained by observation routes and traffic conditions, geophysical exploration profiles tend to bend curved roads for easy observation, however, it must be projected onto a straight line when data processing and analyzing. After projection, we don't know the true position of the obtained crustal structure. Nonetheless, when the results used as an initial constraint condition for other geophysical inversion, such as gravity inversion, we need to know the true position of the data rather than the distance to the starting point. We solved this problem by profile vectorization and reprojection. The method can be used for extraction data of various geophysical exploration profiles, such as seismic reflection profiles, gravity profiles. Keywords: Data extraction, Vectorization, Profile, Geophysical exploration, Python