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Unlike inorganic crystals, metal-organic frameworks do not have a well-developed nanostructure library, and establishing their appropriately diverse and complex architectures remains a major challenge. Here, we demonstrate a general route to control metal-organic framework structure by a solvent-assisted ligand exchange approach. Thirteen different types of metal-organic framework structures have been prepared successfully. To demonstrate a proof of concept application, we used the obtained metal-organic framework materials as precursors for synthesizing nanoporous carbons and investigated their electrochemical Na + storage properties. Due to the unique architecture, the one-dimensional nanoporous carbon derived from double-shelled ZnCo bimetallic zeolitic imidazolate framework nanotubes exhibits high specific capacity as well as superior rate capability and cycling stability. Our study offers an avenue for the controllable preparation of well-designed meta-organic framework structures and their derivatives, which would further broaden the application opportunities of metal-organic framework materials. Metal-organic frameworks are promising for a range of applications, but architectural control is challenging. Here the authors use solvent-assisted ligand exchange to access a variety of metal-organic framework nanomaterials for precursors of nanoporous carbon with sodium ion storage properties.

The inoculants of arbuscular mycorrhizal fungi (AMF) propagated by the in vitro culture system is important in scientific research; however, the long-term storage reduces the spore germination rate. The propagules of AMF consist of three components, including spores, hyphae and colonized root fragments. It is well known that cold storage can improve the germination rate of AMF spores, with limited investigations on the germination of other propagules. In this study, AMF inoculants were stored at 25°C or at 4°C (cold storage) to investigate the effect of cold storage on the propagule viability of the AMF Rhizophagus irregularis DAOM197198. The germination rate of propagules (spores, hyphae, root fragments) and their colonization ability were determined at 3 and 6 months after storage. The results showed that the spore germination rate remained unchanged after storage for 0 and 1 month at 25°C, but decreased rapidly after storage for 3 months. Furthermore, we investigated the hyphal germination rate for the first time. The germination rates of spores, hyphae and root fragments were significantly higher under cold storage compared to those at 25°C. Additionally, we classified the germ tubes of hypha into two types: long-type (L-type) and short type (S-type). The germination rate and the proportion of L-type germ tubes of hyphae significantly increased with cold storage time, which was conducive to colonization. The results of mycorrhizal colonization confirmed that cold storage significantly increased the colonization of hypha compared with 25°C treatment. Cold storage may break the dormancy of AMF propagules and activate related enzymes to promote the germination and colonization of propagules, which needs further investigation.

Phyllosphere microbiome plays important roles in crop adaptation to the changing environments. Perennial woody crops undergo annual cycles with the changing weather parameters and the biological factors, which might shape the phyllosphere microbial community. In this study, we aimed to investigate the dynamics of phyllosphere microbiome of pomelo ( Citrus maxima (Burm.) Merr.), an economically important horticultural crops worldwide, and to compare the respective contribution of the weather parameters and the biotic factors to the microbial community assembly, with special focus on the amino acids in leaves. Hi-Seq analysis revealed that both bacterial and fungal communities showed annual cycle dynamics, and the bacterial community in summer was much different from those in other seasons probably due to high temperature and precipitation. However, contribution of the biotic factors (e.g., leaf traits) (12%-29%) to microbial community assembly was higher than that of the weather parameters (4%-15%). Redundancy analysis indicated that the leaf amino acids significantly affected bacterial community while sugars significantly affected fungal community, highlighting the differential patterns of bacterial and fungal community as affected by the biotic factors. Finally, structure equation model showed that the weather parameters influenced microbial community colonizing pomelo leaves both in a direct way and in an indirect way via leaf traits (mainly amino acids). These results demonstrate the primary role of weather parameters and the key role of leaf amino acids in shaping phyllosphere microbiome.

With the rapid global demand for mariculture products in recent years, the use of antibiotics has increased intensively in the mariculture area. Current research on antibiotic residues in mariculture environments is limited, and less information is available on the presence of antibiotics in tropical waters, limiting a comprehensive understanding of their environmental presence and risk. Therefore, this study investigated the environmental occurrence and distribution of 50 antibiotics in the near-shore aquaculture waters of Fengjia Bay. A total of 21 antibiotics were detected in 12 sampling sites, including 11 quinolones, 5 sulfonamides, 4 tetracyclines, and 1 chloramphenicol; the quinolones pyrimethamine (PIP), delafloxacin (DAN), flurofloxacin (FLE), ciprofloxacin (CIP), norfloxacin (NOR), pefloxacin (PEF), enrofloxacin (ENO), and minocycline (MNO) of the tetracycline class were detected in all sampling points. The total antibiotic residue concentrations in the study area ranged from 153.6 to 1550.8 ng/L, the tetracycline antibiotics were detected in the range of 10 to 1344.7 ng/L, and the chloramphenicol antibiotics were detected in the range of 0 to 106.9 ng/L. The detected concentrations of quinolones ranged from 81.3 to 136.1 ng/L, and the residual concentrations of sulfonamide antibiotics ranged from 0 to 313.7 ng/L. The correlation analysis with environmental factors revealed that pH, temperature, conductivity, salinity, NH3−-N, and total phosphorus had a strong correlation with antibiotics. Based on PCA analysis, the main sources of antibiotic pollution in the area were determined to be the discharge of farming wastewater and domestic sewage. The ecological risk assessment indicated that the residual antibiotics in the water environment of the near-shore waters of Fengjiawan had certain risks to the ecosystem. Among them, CIP, NOR, sulfamethoxazole (TMP), ofloxacin (OFL), enrofloxacin (ENO), sulfamethoxazole (SMX), and FLE showed medium to high risk. Therefore, it is recommended to regulate the use of these antibiotics and the discharge and treatment of culturing wastewater, and measures should be taken to reduce the environmental pollution caused by antibiotics and to monitor the long-term ecological risk of antibiotics in the region. Overall, our results provide an important reference for understanding the distribution and ecological risk of antibiotics in Fengjiawan.

The rhizosphere microflora are key determinants that contribute to plant health and productivity, which can support plant nutrition and resistance to biotic and abiotic stressors. However, limited research is conducted on the areca palm rhizosphere microbiota. To further study the effect of the areca palm’s developmental stages on the rhizosphere microbiota, the rhizosphere microbiota of areca palm (Areca catechu) grown in its main producing area were examined in Wanning, Hainan province, at different vegetation stages by an Illumina Miseq sequence analysis of the 16S ribosomal ribonucleic acid and internal transcribed spacer genes. Significant shifts of the taxonomic composition of the bacteria and fungi were observed in the four stages. Burkholderia-Caballeronia-Paraburkholderia were the most dominant group in stage T1 and T2; the genera Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium were decreased significantly from T1 to T2; and the genera Acidothermus and Bacillus were the most dominant in stage T3 and T4, respectively. Meanwhile, Neocosmospora, Saitozyma, Penicillium, and Trichoderma were the most dominant genera in the stage T1, T2, T3, and T4, respectively. Among the core microbiota, the dominant bacterial genera were Burkholderia-Caballeronia-Paraburkholderia and Bacillus, and the dominant fungal genera were Saitozyma and Trichoderma. In addition, we identified five bacterial genera and five fungal genera that reached significant levels during development. Finally, we constructed the OTU (top 30) interaction network of bacteria and fungi, revealed its interaction characteristics, and found that the bacterial OTUs exhibited more extensive interactions than the fungal OTUs. Understanding the rhizosphere soil microbial diversity characteristics of the areca palm could provide the basis for exploring microbial association and maintaining the areca palm’s health.

Rational construction of binder-free electrode is regarded as a promising way to improve the electrochemical performance of supercapacitor. Herein, we synthesize a hierarchical NiCo2O4/MnO2 core–shell nanosheets arrays by two-step cathodic electrodeposition method. The optimized NiCo2O4/MnO2 electrode prepared by the electrodeposition potential of − 1.8 V for 240 s shows a large specific capacitance of 3.81 F cm−2 at 2 mA cm−2. The enhanced electrochemical performance is attributed to the unique core–shell structure of NiCo2O4/MnO2 nanosheets arrays with appropriate interspaces between nanosheets that can offer more active sites and accelerate ion/electron transfer rate. Besides, the NiCo2O4/MnO2//AC flexible asymmetric supercapacitor achieves a high energy density of 2.55 mWh cm−3 with good stability (86.1% of initial capacitance can remain after 10000 cycles), indicating the perfect energy storage features.

In this paper, we report the in situ growth of Ni x Cu 1-x (x = 0, 0.25, 0.50, 0.75 and 1.0) alloy catalysts to anchor and decorate a redox-reversible Nb 1.33 Ti 0.67 O 4 ceramic substrate with the aim of tailoring the electrocatalytic activity of the composite materials through direct exsolution of metal particles from the crystal lattice of a ceramic oxide in a reducing atmosphere at high temperatures. Combined analysis using XRD, SEM, EDS, TGA, TEM and XPS confirmed the completely reversible exsolution/dissolution of the Ni x Cu 1-x alloy particles during the redox cycling treatments. TEM results revealed that the alloy particles were exsolved to anchor onto the surface of highly electronically conducting Nb 1.33 Ti 0.67 O 4 in the form of heterojunctions. The electrical properties of the nanosized Ni x Cu 1-x /Nb 1.33 Ti 0.67 O 4 were systematically investigated and correlated to the electrochemical performance of the composite electrodes. A strong dependence of the improved electrode activity on the alloy compositions was observed in reducing atmospheres at high temperatures. Direct electrolysis of CO 2 at the Ni x Cu 1-x /Nb 1.33 Ti 0.67 O 4 composite cathodes was investigated in solid-oxide electrolysers. The CO 2 splitting rates were observed to be positively correlated with the Ni composition; however, the Ni 0.75 Cu 0.25 combined the advantages of metallic nickel and copper and therefore maximised the current efficiencies.

Anthocyanins are the main pigments in flowers and fruits. These pigments are responsible for the red, red-purple, violet, and purple color in plants, and act as insect and animal attractants. In this study, phenotypic analysis of the purple flower color in eggplant indicated that the flower color is controlled by a single dominant gene, FAS. Using an F2 mapping population derived from a cross between purple-flowered ‘Blacknite’ and white-flowered ‘Small Round’, Flower Anthocyanidin Synthase (FAS) was fine mapped to an approximately 165.6-kb region between InDel marker Indel8-11 and Cleaved Amplified Polymorphic Sequences (CAPS) marker Efc8-32 on Chromosome 8. On the basis of bioinformatic analysis, 29 genes were subsequently located in the FAS target region, among which were two potential Anthocyanidin Synthase (ANS) gene candidates. Allelic sequence comparison results showed that one ANS gene (Sme2.5_01638.1_g00003.1) was conserved in promoter and coding sequences without any nucleotide change between parents, whereas four single-nucleotide polymorphisms were detected in another ANS gene (Sme2.5_01638.1_g00005.1). Crucially, a single base pair deletion at site 438 resulted in premature termination of FAS, leading to the loss of anthocyanin accumulation. In addition, FAS displayed strong expression in purple flowers compared with white flowers and other tissues. Collectively, our results indicate that Sme2.5_01638.1_g00005.1 is a good candidate gene for FAS, which controls anthocyanidin synthase in eggplant flowers. The present study provides information for further potential facilitate genetic engineering for improvement of anthocyanin levels in plants.

The AlCoCrFeNi powder was added to WC powder as a binder and Y2O3/ZrO2 was doped by the wet chemical method as grain-growth inhibitors. The WC-Y2O3-ZrO2-10AlCoCrFeNi composite powders were sintered by spark plasma sintering to obtain an alloy. The microstructure and properties of the cemented carbide were studied. The result showed that the rare-earth-oxide (Y2O3/ZrO2)-refined grain size of the alloy and the high-entropy alloy binder provided the alloy with better hardness and toughness. The AlCoCrFeNi diffused slowly between the WC grains because of a delayed diffusion effect and Cr having a low affinity for the WC matrix. During the dynamic process of the WC particles’ dissolution and precipitation growth, the Fe, Co, and Ni that had a better affinity for the WC matrix diffused and distributed more smoothly, which increased the strength and toughness of the alloy. When the temperature of the SPS sintering was 1250 °C, the WC-Y2O3-ZrO2-10AlCoCrFeNi cemented carbide had the best properties, which was a Vickers hardness of 1888.14 HV and a fracture toughness of 14.76 MPa·m1/2.

Three-dimensional (3D) nickel foam supported Ni2P/NiO/CeO2 nanoflake arrays (NFAs) were synthesized by hydrothermal, anneal and low-temperature phosphatizing processes. As-prepared samples were systematically researched by SEM, XRD, XPS, TEM, EDS and HRTEM technology. Cyclic Voltammgrams and Chronoamperometry technology were used to measure the sensors performance of Ni2P/NiO/CeO2 NFAs. The results indicated that non-enzymatic glucose sensors based on Ni2P/NiO/CeO2 NFAs exhibited a high sensitivity of 28.23 mA cm−2 mM−1 and good anti-interference ability, suggesting that the 3D nickel foam supported Ni2P/NiO/CeO2 NFAs as a non-enzymatic glucose sensor is promising for practical applications.