Production of Renewable Hydrocarbon Biofuels with Lignocellulose and Its Derivatives over Heterogeneous Catalysts.

In recent years, the issues of global warming and CO2 emission reduction have garnered increasing global attention. In the 21st Conference of the Parties (convened in Paris in 2015), 179 nations and the European Union signed a pivotal agreement to limit the global temperature increase of this century to well below 2 K above preindustrial levels. To fulfill this objective, extensive research has been conducted to use renewable energy sources as potential replacements for traditional fossil fuels. Among them, the production of hydrocarbon transportation fuels from CO2-neutral and renewable biomass has proven to be a particularly promising solution due to its compatibility with existing infrastructure. This review systematically summarizes research progress in the synthesis of liquid hydrocarbon biofuels from lignocellulose during the past two decades. Based on the chemical structure (including n-paraffins, iso-paraffins, aromatics, and cycloalkanes) of hydrocarbon transportation fuels, the synthesis pathways of these biofuels are discussed in four separate sections. Furthermore, this review proposes three guiding principles for the design of practical hydrocarbon biofuels, providing insights into future directions for the development of viable biomass-derived liquid fuels.

Suppressing Metal Leaching and Sintering in Hydroformylation Reaction by Modulating the Coordination of Rh Single Atoms with Reactants.

Hydroformylation reaction is one of the largest homogeneously catalyzed industrial processes yet suffers from difficulty and high cost in catalyst separation and recovery. Heterogeneous single-atom catalysts (SACs), on the other hand, have emerged as a promising alternative due to their high initial activity and reasonable regioselectivity. Nevertheless, the stability of SACs against metal aggregation and leaching during the reaction has rarely been addressed. Herein, we elucidate the mechanism of Rh aggregation and leaching by investigating the structural evolution of Rh1@silicalite-1 SAC in response to different adsorbates (CO, H2, alkene, and aldehydes) by using diffuse reflectance infrared Fourier transform spectroscopy, X-ray adsorption fine structure, and scanning transmission electron microscopy techniques and kinetic studies. It is discovered that the aggregation and leaching of Rh are induced by the strong adsorption of CO and aldehydes on Rh, as well as the reduction of Rh3+ by CO/H2 which weakens the binding of Rh with support. In contrast, alkene effectively counteracts this effect by the competitive adsorption on Rh atoms with CO/aldehyde, and the disintegration of Rh clusters. Based on these results, we propose a strategy to conduct the reaction under conditions of high alkene concentration, which proves to be able to stabilize Rh single atom against aggregation and/or leaching for more than 100 h time-on-stream.

Ethylene Methoxycarbonylation over Heterogeneous Pt1/MoS2 Single-Atom Catalyst: Metal-Support Concerted Catalysis.

Ethylene methoxycarbonylation (EMC) to methyl propanoate (MP) is an industrially important reaction and commercially uses a homogeneous Pd-phosphine organometallic complex as the catalyst and corrosive strong acid as the promoter. In this work, we develop a Pt1/MoS2 heterogeneous single-atom catalyst (SAC) which exhibits high activity, selectivity, and good recyclability for EMC reaction without need of any liquid acid. The production rate of MP achieves 0.35 gMP gcat-1 h-1 with MP selectivity of 91.1% at 1 MPa CO, 1 MPa C2H4, and 160 °C, which can be doubled at 2 MPa CO and corresponds to 320.1 molMP molPt-1 h-1, at least 1 order of magnitude higher than the earlier reported heterogeneous catalyst and even comparable to some of homogeneous catalyst. Advanced characterizations and DFT calculations reveal that all the Pt single atoms are located at the Mo vacancies along the Mo edge of the MoS2 nanosheets, forming pocket-like Mo-S-Pt1-S-Mo ensembles with uniform and well-defined structure. Methanol is first adsorbed and dissociated on Mo sites, and the produced H spillovers to the adjacent Pt site forming Pt-H species which then activate ethylene, forming Pt-ethyl species. Meanwhile, CO adsorbed on the other Mo site reacts with the Pt-ethyl species, yielding propionyl species, and this carbonylation is the rate-determining step. The final methoxylation step proceeds via the nucleophilic attack of propionyl species by -OCH3 affording the final product MP. Such a metal-support concerted catalysis enabled by the Mo-S-Pt1-S-Mo multisite ensemble opens a new avenue for SACs to promote the multimolecular reactions that prevail in homogeneous catalysis.

Assembly and comparative analysis of the complete mitochondrial and chloroplast genome of Cyperus stoloniferus (Cyperaceae), a coastal plant possessing saline-alkali tolerance.

BACKGROUND: Cyperus stoloniferus is an important species in coastal ecosystems and possesses economic and ecological value. To elucidate the structural characteristics, variation, and evolution of the organelle genome of C. stoloniferus, we sequenced, assembled, and compared its mitochondrial and chloroplast genomes. RESULTS: We assembled the mitochondrial and chloroplast genomes of C. stoloniferus. The total length of the mitochondrial genome (mtDNA) was 927,413 bp, with a GC content of 40.59%. It consists of two circular DNAs, including 37 protein-coding genes (PCGs), 22 tRNAs, and five rRNAs. The length of the chloroplast genome (cpDNA) was 186,204 bp, containing 93 PCGs, 40 tRNAs, and 8 rRNAs. The mtDNA and cpDNA contained 81 and 129 tandem repeats, respectively, and 346 and 1,170 dispersed repeats, respectively, both of which have 270 simple sequence repeats. The third high-frequency codon (RSCU > 1) in the organellar genome tended to end at A or U, whereas the low-frequency codon (RSCU < 1) tended to end at G or C. The RNA editing sites of the PCGs were relatively few, with only 9 and 23 sites in the mtDNA and cpDNA, respectively. A total of 28 mitochondrial plastid DNAs (MTPTs) in the mtDNA were derived from cpDNA, including three complete trnT-GGU, trnH-GUG, and trnS-GCU. Phylogeny and collinearity indicated that the relationship between C. stoloniferus and C. rotundus are closest. The mitochondrial rns gene exhibited the greatest nucleotide variability, whereas the chloroplast gene with the greatest nucleotide variability was infA. Most PCGs in the organellar genome are negatively selected and highly evolutionarily conserved. Only six mitochondrial genes and two chloroplast genes exhibited Ka/Ks > 1; in particular, atp9, atp6, and rps7 may have undergone potential positive selection. CONCLUSION: We assembled and validated the mtDNA of C. stoloniferus, which contains a 15,034 bp reverse complementary sequence. The organelle genome sequence of C. stoloniferus provides valuable genomic resources for species identification, evolution, and comparative genomic research in Cyperaceae.

High quantum efficiency of hydrogen production from methanol aqueous solution with PtCu-TiO2 photocatalysts.

Methanol with 12.5 wt% H2 content is widely considered a liquid hydrogen medium. Taking into account water with 11.1 wt% H2 content, H2 synthesis from the mixture of water and methanol is a promising method for on-demand hydrogen production. We demonstrate an atomic-level catalyst design strategy using the synergy between single atoms and nanodots for H2 production. The PtCu-TiO2 sandwich photocatalyst achieves a remarkable H2 formation rate (2,383.9 µmol h-1) with a high apparent quantum efficiency (99.2%). Furthermore, the oxidation product is a high-value chemical formaldehyde with 98.6% selectivity instead of CO2, leading to a nearly zero-carbon-emission process. Detailed investigations indicate a dual role of the copper atoms: an electron acceptor to facilitate photoelectron transfer to Pt, and a hole acceptor for the selective oxidation of methanol to formaldehyde, thus avoiding over-oxidation to CO2. The synergy between Pt nanodots and Cu single atoms together reduces the activation energy of this process to 13.2 kJ mol-1.

Mutator-like transposable element 9A interacts with metacaspase 1 and modulates the incidence of Al-induced programmed cell death in peanut.

The toxicity of aluminum (Al) in acidic soil inhibits plant root development and reduces crop yields. In the plant response to Al toxicity, the initiation of programmed cell death (PCD) appears to be an important mechanism for the elimination of Al-damaged cells to ensure plant survival. In a previous study, the type I metacaspase AhMC1 was found to regulate the Al stress response and to be essential for Al-induced PCD. However, the mechanism by which AhMC1 is altered in the peanut response to Al stress remained unclear. Here, we show that a nuclear protein, mutator-like transposable element 9A (AhMULE9A), directly interacts with AhMC1 in vitro and in vivo. This interaction occurs in the nucleus in peanut and is weakened during Al stress. Furthermore, a conserved C2HC zinc finger domain of AhMULE9A (residues 735-751) was shown to be required for its interaction with AhMC1. Overexpression of AhMULE9A in Arabidopsis and peanut strongly inhibited root growth with a loss of root cell viability under Al treatment. Conversely, knock down of AhMULE9A in peanut significantly reduced Al uptake and Al inhibition of root growth, and alleviated the occurrence of typical hallmarks of Al-induced PCD. These findings provide novel insight into the regulation of Al-induced PCD.

Virological evaluation of natural and modified attapulgite against porcine epidemic diarrhoea virus.

BACKGROUND: The Porcine Epidemic Diarrhea Virus (PEDV) has caused significant economic losses in the global swine industry. As a potential drug for treating diarrhea, the antiviral properties of attapulgite deserve further study. METHODS: In this study, various methods such as RT-qPCR, Western blot, viral titer assay, Cytopathic Effect, immunofluorescence analysis and transmission electron microscopy were used to detect the antiviral activity of attapulgite and to assess its inhibitory effect on PEDV. RESULTS: When exposed to the same amount of virus, there was a significant decrease in the expression of the S protein, resulting in a viral titer reduction from 10-5.613 TCID50/mL to 10-2.90 TCID50/mL, which represents a decrease of approximately 102.6 folds. Results of cytopathic effect and indirect immunofluorescence also indicate a notable decrease in viral infectivity after attapulgite treatment. Additionally, it was observed that modified materials after acidification had weaker antiviral efficacy compared to powdered samples that underwent ultrasonic disintegration, which showed the strongest antiviral effects. CONCLUSION: As a result, Attapulgite powders can trap and adsorb viruses to inhibit PEDV in vitro, leading to loss of viral infectivity. This study provides new materials for the development of novel disinfectants and antiviral additives.

Porous superabsorbent composites prepared from aqueous foam template and application evaluation.

Rapid water absorption is very important for the application of superabsorbent polymers under dry or semi-dry conditions, but there are currently few relevant studies. In this context, a novel porous superabsorbent of chitosan-grafted acrylic copolymer-2-acrylamido-2-methylpropanesulfonic acid/sapindus mukorossi pericarp/calcined oil shale semi-coke (CS-g-P(AA-co-AMPS)/SMP/COSSC) was prepared by a green and convenient foam template method, which was triggered by redox polymerization. The rich pore structure of the porous superabsorbent was conducive to accelerating the water absorption rate. It only took 15 min to reach a swelling capacity of 650 g g-1 in distilled water. Soil experiments show that even with the addition of 0.5 wt% porous superabsorbent, the soil water retention time can be extended to 7 days. Finally, it was applied to the growth of cabbage seeds and it was found that the growth was significantly improved. Based on these excellent properties, we expect to provide a valuable reference for the preparation of fast-absorbing materials through the green water-based foam template method, contributing to sustainable agriculture.

De Novo Assembly and Comparative Analysis of Mitochondrial Genomes of Two Pueraria montana Varieties.

Pueraria montana is a species with important medicinal value and a complex genetic background. In this study, we sequenced and assembled the mitochondrial (mt) genomes of two varieties of P. montana. The mt genome lengths of P. montana var. thomsonii and P. montana var. montana were 457,390 bp and 456,731 bp, respectively. Both P. montana mitogenomes showed a multi-branched structure consisting of two circular molecules, with 56 genes annotated, comprising 33 protein-coding genes, 18 tRNA genes (trnC-GCA and trnM-CAU are multi-copy genes), and 3 rRNA genes. Then, 207 pairs of long repeats and 96 simple sequence repeats (SSRs) were detected in the mt genomes of P. montana, and 484 potential RNA-editing sites were found across the 33 mitochondrial protein-coding genes of each variety. Additionally, a syntenic sequence analysis showed a high collinearity between the two mt genomes. This work is the first to analyze the mt genomes of P. montana. It can provide information that can be used to analyze the structure of mt genomes of higher plants and provide a foundation for future comparative genomic studies and evolutionary biology research in related species.

Co/SiO2 Catalyst for Methoxycarbonylation of Acetylene: On Catalytic Performance and Active Species.

Reppe carbonylation of acetylene is an atom-economic and non-petroleum approach to synthesize acrylic acid and acrylate esters, which are key intermediates in the textile, leather finishing, and polymer industries. In the present work, a noble metal-free Co@SiO2 catalyst was prepared and evaluated in the methoxycarbonylation reaction of acetylene. It was discovered that pretreatment of the catalyst by different reductants (i.e., C2H2, CO, H2, and syngas) greatly improved the catalytic activity, of which Co/SiO2-H2 demonstrated the best performance under conditions of 160 °C, 0.05 MPa C2H2, 4 MPa CO, and 1 h, affording a production rate of 4.38 gMA+MP gcat-1 h-1 for methyl acrylate (MA) and methyl propionate (MP) and 0.91 gDMS gcat-1 h-1 for dimethyl succinate (DMS), respectively. Transmission electron microscopy (TEM), X-ray diffraction (XRD), and diffuse reflectance infrared Fourier transform spectra of CO adsorption (CO-DRIFTS) measurements revealed that an H2 reduction decreased the size of the Co nanoparticles and promoted the formation of hollow architectures, leading to an increase in the metal surface area and CO adsorption on the catalyst. The hot filtration experiment confirmed that Co2(CO)8 was generated in situ during the reaction or at the pre-activation stage, which served as the genuine active species. Our work provides a facile and convenient approach to the in situ synthetization of Co2(CO)8 for a Reppe carbonylation reaction.

Metal-Oxo Electronic Tuning via In Situ CO Decoration for Promoting Methane Conversion to Oxygenates over Single-Atom Catalysts.

Direct methane conversion (DMC) to oxygenates at low temperature is of great value but remains challenging due to the high energy barrier for C-H bond activation. Here, we report that in situ decoration of Pd1-ZSM-5 single atom catalyst (SAC) by CO molecules significantly promoted the DMC reaction, giving the highest turnover frequency of 207 h-1 ever reported at room temperature and ~100 % oxygenates selectivity with H2O2 as oxidant. Combined characterizations and DFT calculations illustrate that the C-atom of CO prefers to coordinate with Pd1, which donates electrons to the Pd1-O active center (L-Pd1-O, L=CO) generated by H2O2 oxidation. The correspondingly improved electron density over Pd-O pair renders a favorable heterolytic dissociation of C-H bond with low energy barrier of 0.48 eV. Applying CO decoration strategy to M1-ZSM-5 (M=Pd, Rh, Ru, Fe) enables improvement of oxygenates productivity by 3.2-11.3 times, highlighting the generalizability of this method in tuning metal-oxo electronic structure of SACs for efficient DMC process.

Converting Glycerol into Valuable Trioses by Cuδ+ -Single-Atom-Decorated WO3 under Visible Light.

Photocatalytic selective oxidation under visible light presents a promising approach for the sustainable transformation of biomass-derived wastes. However, achieving both high conversion and excellent selectivity poses a significant challenge. In this study, two valuable trioses, glyceraldehyde and dihydroxyacetone, are produced from glycerol over Cuδ+ -decorated WO3 photocatalyst in the presence of H2 O2 . The photocatalyst exhibits a remarkable five-fold increase in the conversion rate (3.81 mmol ⋅ g-1 ⋅ h-1 ) while maintaining a high selectivity towards two trioses (46.4 % to glyceraldehyde and 32.9 % to dihydroxyacetone). Through a comprehensive analysis involving X-ray photoelectron spectroscopy measurements with and without light irradiation, electron spin resonance spectroscopy, and isotopic analysis, the critical role of Cu+ species has been explored as efficient hole acceptors. These species facilitate charge transfer, promoting glycerol oxidation by photoholes, followed by coupling with OH- , which are subsequently dehydrated to yield the desired glyceraldehyde and dihydroxyacetone.

Plant Leaf-Inspired Separators with Hierarchical Structure and Exquisite Fluidic Channels for Dendrite-Free Lithium Metal Batteries.

Lithium (Li) metal batteries are among the most promising devices for high energy storage applications but suffer from severe and irregular Li dendrite growth. Here, it is demonstrated that the issue can be well tackled by precisely designing the leaf-like membrane with hierarchical structure and exquisite fluidic channels. As a proof of concept, plant leaf-inspired membrane (PLIM) separators are prepared using natural attapulgite nanorods. The PLIM separators feature super-electrolyte-philicity, high thermal stability and high ion-selectivity. Thus, the separators can guide uniform and directed Li growth on the Li anode. The Li//PLIM//Li cell with limited Li anode shows high Coulombic efficiency and cycling stability over 1500 h with small overpotential and interface impedance. The Li//PLIM//S battery exhibits high initial capacity (1352 mAh g-1 ), cycling stability (0.019% capacity decay per cycle at 1 C over 500 cycles), rate performance (673 mAh g-1 at 4 C), and high operating temperature (65 °C). The separators can also effectively improve reversibility and cycling stability of the Li/Li cell and Li//LFP battery with carbonate-based electrolyte. As such, this work provides fresh insights into the design of bioinspired separators for dendrite-free metal batteries.

Effect of Al2Cu constituent layer thickness discrepancy on the tensile mechanical behavior of Cu/Al2Cu/Al layered composites: a molecular dynamics simulation.

Nano-polycrystalline Cu/Al2Cu/Al layered composites with different layer thicknessesdof single-crystal Al2Cu constituent are constructed. The effects ofdon the strength and fracture modes of nano-polycrystalline Cu/Al2Cu/Al layered composites are systematically investigated by molecular dynamics simulations. The uniaxial tensile results show that the ultimate strength and fracture mode of the nano-polycrystalline Cu/Al2Cu/Al layered composites do not change monotonically with the change of single crystal Al2Cu constituent layer thicknessd, the ultimate strength peaking atd= 2.44 nm, and the toughness reaching the optimum atd= 4.88 nm. The improvement of deformation incompatibility between Cu, Al and Al2Cu components increases the ultimate strength of polycrystalline Cu/Al2Cu/Al laminated composites. Due to the high activity of Cu dislocation and the uniformity of strain distribution of single crystal Al2Cu, the fracture of nano-crystalline Cu/Al2Cu/Al layered composites changes from brittleness to toughness. This study is crucial to establish the organic connection between microstructure and macroscopic properties of Cu/Al layered composites. To provide theoretical basis and technical support for the application of Cu/Al layered composites in high-end fields, such as automotive and marine, aerospace and defense industries.

Mechanochemical preparation of low cost kaolinite-based BiVO4hybrid pigments with high near infrared reflectance.

For accelerate construction of the energy and resource-saving and environmental-friendly society, cleaner preparation of low-cost and high-performance colorful near-infrared reflective inorganic pigments with the decorative function is indispensable to reduce the hazards of urban heat island and simultaneously beautify the appearance of the buildings. Due to the non-toxicity, good chemical stability and narrow band gap, BiVO4has been becoming a promising environment-friendly yellow inorganic pigments among the conventional heavy metals-containing inorganic pigments. In this study, the low-cost and brilliant kaolinite-based BiVO4hybrid pigments were fabricated by cleaner mechanochemical method based on cheap and abundant kaolinite using crystal water of the hydrated metal salts as trace solvent, which could effectively promote the interaction of the involved components at the molecular level during grinding and then decreased the mass transfer resistance for the formation of monoclinic scheelite BiVO4in the following calcination. The obtained hybrid pigments at the optimal preparation conditions exhibited brilliant color properties (D65-10°,L*= 83.45 ± 0.08,a*= 4.17 ± 0.08,b*= 88.59 ± 0.17), high near-infrared reflectance of 86.22%, infrared solar reflectance of 88.14% and high emissivity of 0.9369 in the waveband of 8-13µm. Furthermore, the hybrid pigments could be used for coloring epoxy resin with high emissivity of 0.8782 in 8-13µm. Therefore, the brilliant and low-cost kaolinite-based bismuth yellow hybrid pigments have the enormous potential to be served as colorful functional nanofillers for cooling roofing materials.

Molecular Cloning, Expression Analysis, and Functional Analysis of Nine IbSWEETs in Ipomoea batatas (L.) Lam.

Sugar Will Eventually be Exported Transporter (SWEET) genes play an important regulatory role in plants' growth and development, stress response, and sugar metabolism, but there are few reports on the role of SWEET proteins in sweet potato. In this study, nine IbSWEET genes were obtained via PCR amplification from the cDNA of sweet potato. Phylogenetic analysis showed that nine IbSWEETs separately belong to four clades (Clade I~IV) and contain two MtN3/saliva domains or PQ-loop superfamily and six~seven transmembrane domains. Protein interaction prediction showed that seven SWEETs interact with other proteins, and SWEETs interact with each other (SWEET1 and SWEET12; SWEET2 and SWEET17) to form heterodimers. qRT-PCR analysis showed that IbSWEETs were tissue-specific, and IbSWEET1b was highly expressed during root growth and development. In addition to high expression in leaves, IbSWEET15 was also highly expressed during root expansion, and IbSWEET7, 10a, 10b, and 12 showed higher expression in the leaves. The expression of SWEETs showed a significant positive/negative correlation with the content of soluble sugar and starch in storage roots. Under abiotic stress treatment, IbSWEET7 showed a strong response to PEG treatment, while IbSWEET10a, 10b, and 12 responded significantly to 4 °C treatment and, also, at 1 h after ABA, to NaCl treatment. A yeast mutant complementation assay showed that IbSWEET7 had fructose, mannose, and glucose transport activity; IbSWEET15 had glucose transport activity and weaker sucrose transport activity; and all nine IbSWEETs could transport 2-deoxyglucose. These results provide a basis for further elucidating the functions of SWEET genes and promoting molecular breeding in sweet potato.

Fabrication porous adsorbents templated from aqueous foams using astragalus membranaceus and attapulgite as stabilizer for efficient removal of cationic dyes.

The water-based foam stabilized by the natural surfactant applied in the fabrication of porous materials has attracted extensive attention, as the advantages of cleanness, convenience and low cost. Particularly, the development of a green preparation method has became the main research focus and frontier. In this work, a green liquid foam with high stability was prepared by synergistic stabilization of natural plant astragalus membranaceus (AMS) and attapulgite (APT), and then a novel porous material with sufficient hierarchical pore structure was templated from the foam via a simple free radical polymerization of acrylamide (AM). The characterization results revealed that the amphiphilic molecules from AMS adsorbed onto the water-air interface and formed a protective shell to prevent the bubble breakup, and APT gathered in the plateau border and formed a three-dimensional network structure, which greatly slowed down the drainage rate. The porous material polyacrylamide/astragalus membranaceus/attapulgite (PAM/AMS/APT) showed the excellent adsorption performance for cationic dyes of Methyl Violet (MV) and Methylene Blue (MB) in water, and the maximum adsorption capacity could reach to 709.13 and 703.30 mg/g, respectively. Furthermore, the polymer material enabled to regenerate and cycle via a convenient calcination process, and the adsorption capacity was still higher than 200 mg/g after five cycles. In short, this research provided a new idea for the green preparation of porous materials and the treatment of water pollution.

Synthesis of Cyclopentadiene and Methylcyclopentadiene with Xylose or Extracted Hemicellulose.

Cyclopentadiene (CPD) and methylcyclopentadiene (MCPD) are important intermediates that have been widely used in the production of high-energy-density rocket fuels, polymers and valuable chemicals. Currently, CPD and MCPD are produced from fossil energies at very low yields, which greatly limits their application. As a solution to this problem, we disclose an alternative two-step bio-route to access CPD and MCPD using xylose or extracted hemicellulose as the feedstock. In the first step, cyclopentanone (CPO) was directly produced by the selective hydrogenolysis of xylose or extracted hemicellulose over a commercial Ru/C catalyst in an acid-free toluene/NaCl aqueous solution biphasic system. In the second step, CPO was selectively converted to CPD by a cascade hydrodeoxygenation/dehydrogenation reaction over zinc molybdate catalysts. When methanol was introduced with CPO and hydrogen, MCPD was selectively obtained by a cascade dehydrogenation/aldol condensation/selective hydrodeoxygenation reaction over zinc molybdate catalysts.

Transcriptomic analysis of tuberous root in two sweet potato varieties reveals the important genes and regulatory pathways in tuberous root development.

BACKGROUND: Tuberous root formation and development is a complex process in sweet potato, which is regulated by multiple genes and environmental factors. However, the regulatory mechanism of tuberous root development is unclear. RESULTS: In this study, the transcriptome of fibrous roots (R0) and tuberous roots in three developmental stages (Rl, R2, R3) were analyzed in two sweet potato varieties, GJS-8 and XGH. A total of 22,914 and 24,446 differentially expressed genes (DEGs) were identified in GJS-8 and XGH respectively, 15,920 differential genes were shared by GJS-8 and XGH. KEGG pathway enrichment analysis showed that the DEGs shared by GJS-8 and XGH were mainly involved in "plant hormone signal transduction" "starch and sucrose metabolism" and "MAPK signal transduction". Trihelix transcription factor (Tai6.25300) was found to be closely related to tuberous root enlargement by the comprehensive analysis of these DEGs and weighted gene co-expression network analysis (WGCNA). CONCLUSION: A hypothetical model of genetic regulatory network for tuberous root development of sweet potato is proposed, which emphasizes that some specific signal transduction pathways like "plant hormone signal transduction" "Ca2+signal" "MAPK signal transduction" and metabolic processes including "starch and sucrose metabolism" and "cell cycle and cell wall metabolism" are related to tuberous root development in sweet potato. These results provide new insights into the molecular mechanism of tuberous root development in sweet potato.

Potential-Driven Restructuring of Cu Single Atoms to Nanoparticles for Boosting the Electrochemical Reduction of Nitrate to Ammonia.

Restructuring is ubiquitous in thermocatalysis and of pivotal importance to identify the real active site, yet it is less explored in electrocatalysis. Herein, by using operando X-ray absorption spectroscopy in conjunction with advanced electron microscopy, we reveal the restructuring of the as-synthesized Cu-N4 single-atom site to the nanoparticles of ∼5 nm during the electrochemical reduction of nitrate to ammonia, a green ammonia production route upon combined with the plasma-assisted oxidation of nitrogen. The reduction of Cu2+ to Cu+ and Cu0 and the subsequent aggregation of Cu0 single atoms is found to occur concurrently with the enhancement of the NH3 production rate, both of them are driven by the applied potential switching from 0.00 to -1.00 V versus RHE. The maximum production rate of ammonia reaches 4.5 mg cm-2 h-1 (12.5 molNH3 gCu-1 h-1) with a Faradaic efficiency of 84.7% at -1.00 V versus RHE, outperforming most of the other Cu catalysts reported previously. After electrolysis, the aggregated Cu nanoparticles are reversibly disintegrated into single atoms and then restored to the Cu-N4 structure upon being exposed to an ambient atmosphere, which masks the potential-induced restructuring during the reaction. The synchronous changes of the Cu0 percentage and the ammonia Faradaic efficiency with the applied potential suggests that the Cu nanoparticles are the genuine active sites for nitrate reduction to ammonia, which is corroborated with both the post-deposited Cu NP catalyst and density functional theory calculations.