Exploring and designing a high-performance non-noble metal catalyst for hydrogen evolution reaction(HER)are crucial for the large-scale application of H2 by water electrolysis.Here,novel catalysts with NiMo nanopartic...Exploring and designing a high-performance non-noble metal catalyst for hydrogen evolution reaction(HER)are crucial for the large-scale application of H2 by water electrolysis.Here,novel catalysts with NiMo nanoparticles decorated on reduced graphene oxide(NiMo@r GO)synthesized by a two-step hydrothermal method were reported.Physical characterization results showed that the prepared NiMo@r GO-1 had an irregular lamellar structure,and the NiMo nanoparticles were uniformly dispersed on the rGO.NiMo@rGO-1 exhibited outstanding HER performance in an alkaline environment and required only 93 and 180 mV overpotential for HER in 1.0 M KOH solution to obtain current densities of-10 and-50 mA·cm^(-2),respectively.Stability tests showed that NiMo@rGO-1 had a certain operating stability for32 h.Under the same condition,the performance of NiMo@rGO-1 can be comparable with that of commercial Pt/C catalysts at high current density.The synergistic effect between NiMo particles and lamellate graphene can remarkably promote charge transfer in electrocatalytic reactions.As a result,NiMo@rGO-1 presented the advantages of high intrinsic activity,large specific surface area,and small electrical impedance.The lamellar graphene played a role in dispersion to prevent the aggregation of nanoparticles.The prepared NiMo@rGO-1 can be used in anion exchange membrane water electrolysis to produce hydrogen.This study provides a simple preparation method for efficient and low-cost water electrolysis to produce hydrogen in the future.展开更多
Chaenomeles speciosa(2n=34),a medicinal and edible plant in the Rosaceae,is commonly used in traditional Chinese medicine.To date,the lack of genomic sequence and genetic studies has impeded efforts to improve its med...Chaenomeles speciosa(2n=34),a medicinal and edible plant in the Rosaceae,is commonly used in traditional Chinese medicine.To date,the lack of genomic sequence and genetic studies has impeded efforts to improve its medicinal value.Herein,we report the use of an integrative approach involving PacBio HiFi(third-generation)sequencing and Hi-C scaffolding to assemble a high-quality telomere-to-telomere genome of C.speciosa.The genome comprised 650.4 Mb with a contig N50 of 35.5 Mb.Of these,632.3 Mb were anchored to 17 pseudo-chromosomes,in which 12,4,and 1 pseudo-chromosomes were represented by a single contig,two contigs,and four contigs,respectively.Eleven pseudo-chromosomes had telomere repeats at both ends,and four had telomere repeats at a single end.Repetitive sequences accounted for 49.5%of the genome,while a total of 45515 protein-coding genes have been annotated.The genome size of C.speciosa was relatively similar to that of Malus domestica.Expanded or contracted gene families were identified and investigated for their association with different plant metabolisms or biological processes.In particular,functional annotation characterized gene families that were associated with the biosynthetic pathway of oleanolic and ursolic acids,two abundant pentacyclic triterpenoids in the fruits of C.speciosa.Taken together,this telomere-to-telomere and chromosome-level genome of C.speciosa not only provides a valuable resource to enhance understanding of the biosynthesis of medicinal compounds in tissues,but also promotes understanding of the evolution of the Rosaceae.展开更多
Most of the reported P-type pentatricopeptide repeat(PPR) proteins play roles in organelle RNA stabilization and splicing. However, P-type PPRs involved in both RNA splicing and editing have rarely been reported, and ...Most of the reported P-type pentatricopeptide repeat(PPR) proteins play roles in organelle RNA stabilization and splicing. However, P-type PPRs involved in both RNA splicing and editing have rarely been reported, and their underlying mechanism remains largely unknown. Here, we report a rice floury endosperm22(flo22) mutant with delayed amyloplast development in endosperm cells. Map-based cloning and complementation tests demonstrated that FLO22 encodes a mitochondrion-localized P-type PPR protein.Mutation of FLO22 resulting in defective transsplicing of mitochondrial nad1 intron 1 and perhaps causing instability of mature transcripts affected assembly and activity of complex Ⅰ, and mitochondrial morphology and function. RNA-seq analysis showed that expression levels of many genes involved in starch and sucrose metabolism were significantly down-regulated in the flo22mutant compared with the wild type, whereas genes related to oxidative phosphorylation and the tricarboxylic acid cycle were significantly upregulated. In addition to involvement in splicing as a P-type PPR protein, we found that FLO22 interacted with DYW3, a DYW-type PPR protein, and they may function synergistically in mitochondrial RNA editing. The present work indicated that FLO22 plays an important role in endosperm development and plant growth by participating in nad1 maturation and multi-site editing of mitochondrial messager RNA.展开更多
Intricate assembly of multiple molecular chromophores assisted by protein scaffolds is essential in tuning the optical absorption and energy transfer in the light-harvesting complexes of the photosynthetic systems in ...Intricate assembly of multiple molecular chromophores assisted by protein scaffolds is essential in tuning the optical absorption and energy transfer in the light-harvesting complexes of the photosynthetic systems in nature.However,it remains a challenge to achieve such structural complexity and functionality in synthetic polymer-chromophore systems.Here,we report a series of polyester-tethered pyrrolopyrrole cyanine derivatives and their colloidal nanoparticles dispersed in water,which show tunable J-or H-aggregation excitonic coupling and near-infrared fluorescence by precise control of the polymer chain lengths,composition,and temperature.Moreover,the optimal fluorescence or photothermal effect of the Jaggregate nanoparticles enables broad applications in fluorescence or photoacoustic bioimaging and phototherapy.展开更多
Vascular endothelial growth factor(VEGF)regulates tumor angiogenesis,which is active on the endothelium via VEGF receptor 2(VEGFR-2).The proximal promoter region of VEGFR-2(termed as VEGFR-2 DNA)is guanine-rich,formin...Vascular endothelial growth factor(VEGF)regulates tumor angiogenesis,which is active on the endothelium via VEGF receptor 2(VEGFR-2).The proximal promoter region of VEGFR-2(termed as VEGFR-2 DNA)is guanine-rich,forming G-quadruplex(G4)structures.Here,we demonstrate that VEGFR-2 DNA consists of one symmetrically dimeric 14-mer G4-DNA and one 12-mer sequence-palindromic dsDNA.This G4-DNA adopts an unprecedented folding with five stacked tetrads linked by four broken strands.Its 5’-end part contains an A-tetrad A^(1)•A^(4)•A^(1’)•A^(4’)and one G-tetrad G^(3)•G^(5)•G^(3’)•G^(5’)with two V-shaped loops and two one-nt edge-type loops.Its 3’-end part includes three G-tetrads G^(10)•G^(6)•G^(10’)•G^(6’),G^(11)•G^(7)•G^(11’)•G^(7’)(central)and G^(12)•G^(8)•G^(12’)•G^(8’)spanned by two double-chain-reversal one-nt(C^(9)or C^(9’))loops.Bases G^(13)and G^(13’)stack with G-tetrad G^(12)•G^(8)•G^(12’)•G^(8’).These characteristics make this G4-DNA more stable than reported VEGFR-17T G4 structure.The dsDNA connects with G4-DNA without any interactions,generating a linear assembly with G4-DNA structural bulges.These studies uncover new structural features of VEGFR-2 DNA as a potential drug target by inhibiting VEGFR-2 expression,thereby tumor angiogenesis.展开更多
基金financially supported by the National Natural Science Foundation of China(No.22278125)。
文摘Exploring and designing a high-performance non-noble metal catalyst for hydrogen evolution reaction(HER)are crucial for the large-scale application of H2 by water electrolysis.Here,novel catalysts with NiMo nanoparticles decorated on reduced graphene oxide(NiMo@r GO)synthesized by a two-step hydrothermal method were reported.Physical characterization results showed that the prepared NiMo@r GO-1 had an irregular lamellar structure,and the NiMo nanoparticles were uniformly dispersed on the rGO.NiMo@rGO-1 exhibited outstanding HER performance in an alkaline environment and required only 93 and 180 mV overpotential for HER in 1.0 M KOH solution to obtain current densities of-10 and-50 mA·cm^(-2),respectively.Stability tests showed that NiMo@rGO-1 had a certain operating stability for32 h.Under the same condition,the performance of NiMo@rGO-1 can be comparable with that of commercial Pt/C catalysts at high current density.The synergistic effect between NiMo particles and lamellate graphene can remarkably promote charge transfer in electrocatalytic reactions.As a result,NiMo@rGO-1 presented the advantages of high intrinsic activity,large specific surface area,and small electrical impedance.The lamellar graphene played a role in dispersion to prevent the aggregation of nanoparticles.The prepared NiMo@rGO-1 can be used in anion exchange membrane water electrolysis to produce hydrogen.This study provides a simple preparation method for efficient and low-cost water electrolysis to produce hydrogen in the future.
基金This work was supported by the Key Industries Innovation Chain Major Project,Hubei Province(2021ACA004 and 2022 AC003-01-003).
文摘Chaenomeles speciosa(2n=34),a medicinal and edible plant in the Rosaceae,is commonly used in traditional Chinese medicine.To date,the lack of genomic sequence and genetic studies has impeded efforts to improve its medicinal value.Herein,we report the use of an integrative approach involving PacBio HiFi(third-generation)sequencing and Hi-C scaffolding to assemble a high-quality telomere-to-telomere genome of C.speciosa.The genome comprised 650.4 Mb with a contig N50 of 35.5 Mb.Of these,632.3 Mb were anchored to 17 pseudo-chromosomes,in which 12,4,and 1 pseudo-chromosomes were represented by a single contig,two contigs,and four contigs,respectively.Eleven pseudo-chromosomes had telomere repeats at both ends,and four had telomere repeats at a single end.Repetitive sequences accounted for 49.5%of the genome,while a total of 45515 protein-coding genes have been annotated.The genome size of C.speciosa was relatively similar to that of Malus domestica.Expanded or contracted gene families were identified and investigated for their association with different plant metabolisms or biological processes.In particular,functional annotation characterized gene families that were associated with the biosynthetic pathway of oleanolic and ursolic acids,two abundant pentacyclic triterpenoids in the fruits of C.speciosa.Taken together,this telomere-to-telomere and chromosome-level genome of C.speciosa not only provides a valuable resource to enhance understanding of the biosynthesis of medicinal compounds in tissues,but also promotes understanding of the evolution of the Rosaceae.
基金supported by grants from the National Key R&D Program of China (2021YFF1000200)National Natural Science Foundation of China (31901513)+6 种基金the “JBGS” Project of Seed Industry Revitalization in Jiangsu Province (JBGS [2021]008)Jiangsu Province Agriculture Independent Innovation Fund Project (CX(19)1002)the Fundamental Research Funds for the Central Universities (KJQN202005)the China Postdoctoral Science Foundation (2019M661864)also supported by the Key Laboratory of Biology, Genetics, and Breeding of Japonica Rice in Mid-lower Yangtze River, Ministry of Agriculture, Chinathe Jiangsu Collaborative Innovation Center for Modern Crop ProductionNational Observation and Research Station of Rice Germplasm Resources, Nanjing, Jiangsu。
文摘Most of the reported P-type pentatricopeptide repeat(PPR) proteins play roles in organelle RNA stabilization and splicing. However, P-type PPRs involved in both RNA splicing and editing have rarely been reported, and their underlying mechanism remains largely unknown. Here, we report a rice floury endosperm22(flo22) mutant with delayed amyloplast development in endosperm cells. Map-based cloning and complementation tests demonstrated that FLO22 encodes a mitochondrion-localized P-type PPR protein.Mutation of FLO22 resulting in defective transsplicing of mitochondrial nad1 intron 1 and perhaps causing instability of mature transcripts affected assembly and activity of complex Ⅰ, and mitochondrial morphology and function. RNA-seq analysis showed that expression levels of many genes involved in starch and sucrose metabolism were significantly down-regulated in the flo22mutant compared with the wild type, whereas genes related to oxidative phosphorylation and the tricarboxylic acid cycle were significantly upregulated. In addition to involvement in splicing as a P-type PPR protein, we found that FLO22 interacted with DYW3, a DYW-type PPR protein, and they may function synergistically in mitochondrial RNA editing. The present work indicated that FLO22 plays an important role in endosperm development and plant growth by participating in nad1 maturation and multi-site editing of mitochondrial messager RNA.
基金Chinese University of Hong Kong,Shenzhen,Grant/Award Number:UDF01001806Nanyang Technological University,Grant/Award Numbers:AcRFTier2(ARC36/13),AcRFTier1(2016-T1-001-2142018-T1-001-173)。
文摘Intricate assembly of multiple molecular chromophores assisted by protein scaffolds is essential in tuning the optical absorption and energy transfer in the light-harvesting complexes of the photosynthetic systems in nature.However,it remains a challenge to achieve such structural complexity and functionality in synthetic polymer-chromophore systems.Here,we report a series of polyester-tethered pyrrolopyrrole cyanine derivatives and their colloidal nanoparticles dispersed in water,which show tunable J-or H-aggregation excitonic coupling and near-infrared fluorescence by precise control of the polymer chain lengths,composition,and temperature.Moreover,the optimal fluorescence or photothermal effect of the Jaggregate nanoparticles enables broad applications in fluorescence or photoacoustic bioimaging and phototherapy.
基金supported by the National Natural Science Foundation of China(NSFC)under Nos.22174155,22177127 and 21977110。
文摘Vascular endothelial growth factor(VEGF)regulates tumor angiogenesis,which is active on the endothelium via VEGF receptor 2(VEGFR-2).The proximal promoter region of VEGFR-2(termed as VEGFR-2 DNA)is guanine-rich,forming G-quadruplex(G4)structures.Here,we demonstrate that VEGFR-2 DNA consists of one symmetrically dimeric 14-mer G4-DNA and one 12-mer sequence-palindromic dsDNA.This G4-DNA adopts an unprecedented folding with five stacked tetrads linked by four broken strands.Its 5’-end part contains an A-tetrad A^(1)•A^(4)•A^(1’)•A^(4’)and one G-tetrad G^(3)•G^(5)•G^(3’)•G^(5’)with two V-shaped loops and two one-nt edge-type loops.Its 3’-end part includes three G-tetrads G^(10)•G^(6)•G^(10’)•G^(6’),G^(11)•G^(7)•G^(11’)•G^(7’)(central)and G^(12)•G^(8)•G^(12’)•G^(8’)spanned by two double-chain-reversal one-nt(C^(9)or C^(9’))loops.Bases G^(13)and G^(13’)stack with G-tetrad G^(12)•G^(8)•G^(12’)•G^(8’).These characteristics make this G4-DNA more stable than reported VEGFR-17T G4 structure.The dsDNA connects with G4-DNA without any interactions,generating a linear assembly with G4-DNA structural bulges.These studies uncover new structural features of VEGFR-2 DNA as a potential drug target by inhibiting VEGFR-2 expression,thereby tumor angiogenesis.
