The hybridization between oxygen 2p and transition-metal 3d states largely determines the electronic structure near the Fermi level and related functionalities of transition-metal oxides(TMOs).Considerable efforts hav...The hybridization between oxygen 2p and transition-metal 3d states largely determines the electronic structure near the Fermi level and related functionalities of transition-metal oxides(TMOs).Considerable efforts have been made to manipulate the p-d hybridization in TMOs by tailoring the spatial orbital overlap via structural engineering.Here,we demonstrate enhanced p-d hybridization in Ba^(2+)-doped LaNiO_(3)epitaxial films by simultaneously modifying both the spatial and energetic overlaps between the O-2p and Ni-3d orbitals.Combining x-ray absorption spectroscopy and firstprinciples calculations,we reveal that the enhanced hybridization stems from the synergistic effects of a reduced chargetransfer energy due to hole injection and an increased spatial orbital overlap due to straightening of Ni-O-Ni bonds.We further show that the enhanced p-d hybridization can be utilized to promote the oxygen evolution activity of LaNiO_(3).This work sheds new insights into the fine-tuning of the electronic structures of TMOs for enhanced functionalities.展开更多
Introduction Early cancer detection represents a critical evolution in healthcare,addressing a significant pain point in cancer treatment:the tendency for diagnoses to occur at advanced stages.Traditionally,many cance...Introduction Early cancer detection represents a critical evolution in healthcare,addressing a significant pain point in cancer treatment:the tendency for diagnoses to occur at advanced stages.Traditionally,many cancers are not identified until they have progressed to late stages,where treatment options become limited,less effective,and more costly.This late detection results in poorer prognoses,higher mortality rates,and increased healthcare costs.Without early detection tools like Fluorescence In Situ Hybridization(FISH),these challenges persist,leaving patients with fewer opportunities for successful outcomes.展开更多
The biological species concept defines species as groups of actually or potentially interbreeding natural populations that are reproductively isolated from other such groups(Mayr,1942).Reproductive isolation,whether p...The biological species concept defines species as groups of actually or potentially interbreeding natural populations that are reproductively isolated from other such groups(Mayr,1942).Reproductive isolation,whether prezygotic or postzygotic,plays a central role in maintaining species boundaries.However,hybridization between closely related taxa can challenge these boundaries and provide insight into speciation,gene flow,and evolutionary processes(Coyne and Orr,2004).展开更多
Photocatalytic hydrogen(H_(2))production using solar energy is a cutting-edge green technology that holds great potential for addressing the urgent fuel and environmental crises[1–3].To achieve high-efficiency H_(2) ...Photocatalytic hydrogen(H_(2))production using solar energy is a cutting-edge green technology that holds great potential for addressing the urgent fuel and environmental crises[1–3].To achieve high-efficiency H_(2) production,cocatalyst modification is commonly employed to provide active sites for the hydrogen evolution reaction(HER)[4,5].In this context,the kinetics of hydrogen adsorption and desorption at these active sites play a crucial role in enhancing overall photocatalytic H_(2) production efficiency.However,the H adsorption/desorption kinetics often exhibit a trade-off,presenting a significant challenge in achieving an optimal equilibrium between Hads and Hdes in many cocatalyst systems.Therefore,fine-tuning the active sites to optimize the H_(2) evolution kinetics is essential for improving photocatalytic activity[6].展开更多
Layered double hydroxides(LDHs)are potential cathode materials for aqueous magnesium-ion batteries(AMIBs).However,the low capacity and sluggish kinetics significantly limit their electrochemical performance in AMIBs.H...Layered double hydroxides(LDHs)are potential cathode materials for aqueous magnesium-ion batteries(AMIBs).However,the low capacity and sluggish kinetics significantly limit their electrochemical performance in AMIBs.Herein,we find that oxygen vacancies can significantly boost the capacity,electrochemical kinetics,and structure stability of LDHs.The corresponding structure-performance relationship and energy storage mechanism are elaborated through exhaustive in/ex-situ experimental characterizations and density functional theory(DFT)calculations.Specially,in-situ Raman and DFT calculations reveal that oxygen vacancies elevate orbital energy of O 2p and electron density of O atoms,thereby enhancing the orbital hybridization of O 2p with Ni/Co 3d.This facilitates electron transfer between O and adjacent Ni/Co atoms and improves the covalency of Ni–O and Co–O bonds,which activates Ni/Co atoms to release more capacity and stabilizes the Ov-NiCo-LDH structure.Moreover,the distribution of relaxation times(DRT)and molecular dynamics(MD)simulations disclose that the enhanced d-p orbital hybridization optimizes the electronic structure of Ov-NiCo-LDH,which distinctly reduces the diffusion energy barriers of Mg^(2+)and improves the charge transfer kinetics of Ov-NiCo-LDH.Consequently,the assembled Ov-NiCo-LDH//active carbon(AC)and Ov-NiCo-LDH//perylenediimide(PTCDI)AMIBs can both deliver high specific discharge capacity(182.7 and 59.4 mAh g^(−1)at 0.5 A g^(−1),respectively)and long-term cycling stability(85.4%and 89.0%of capacity retentions after 2500 and 2400 cycles at 1.0 A g^(−1),respectively).In addition,the practical prospects for Ov-NiCo-LDH-based AMIBs have been demonstrated in different application scenarios.This work not only provides an effective strategy for obtaining high-performance cathodes of AMIBs,but also fundamentally elucidates the inherent mechanisms.展开更多
Asymmetric single-atom catalysts(ASACs)have attracted much attention owing to their excellent catalytic properties.However,the relationship between asymmetric coordination and the spin states of metal sites remains un...Asymmetric single-atom catalysts(ASACs)have attracted much attention owing to their excellent catalytic properties.However,the relationship between asymmetric coordination and the spin states of metal sites remains unclear.Additionally,the modulation of reactive oxygen species in Fenton-like reactions remains challenging.Herein,a novel strategy is reported for the rational design of highly loaded Co ASACs(CoN_(1)C_(2)/C_(2)N)immobilized on three-dimensional flower-like C_(2)N using an in situ-generated carbon defect method.In particular,the asymmetrically tricoordinated CoN_(1)C_(2)/C_(2)N exhibited excellent catalytic activity for sulfachloropyridazine degradation,with a turnover frequency of 36.8 min^(–1).Experimental results and theoretical calculations revealed that the electron spin state of the Co-active sites was transferred from the low-spin configuration(t_(2g)^(6)e_(g)^(1))to the high-spin configuration(t_(2g)^(5)e_(g)^(2))owing to asymmetric coordination.The high-spin Co 3d orbital in CoN_(1)C_(2)/C_(2)N possessed more unpaired electrons and therefore,had a strong ability to gain electrons from the O 2p orbitals of HSO_(5)^(–),boosting d-p orbital hybridization.More importantly,the spin-electron filling in theσ^(*)orbital of high-spin Co 3d−O 2p accelerated the desorption of^(*)SO_(5)•^(−),which acted as a rate-limiting step in the reaction,thus facilitating more^(1)O_(2)generation.This study provides an innovative synthetic route for practical ASACs and clarifies the critical relationship between structure and spin state,paving the way for advancements in environmental remediation and energy conversion applications.展开更多
The intergeneric hybridization between Brassica napus L. cv. oro and Matthiola incana (L.) R. Br. was carried out to study the phytogenetic peculiarities of the hybrid plants. In order to improve the oil quality of ra...The intergeneric hybridization between Brassica napus L. cv. oro and Matthiola incana (L.) R. Br. was carried out to study the phytogenetic peculiarities of the hybrid plants. In order to improve the oil quality of rape seed, ovaries of B. napus pollinated with pollen of M. incana, were cut off and inoculated onto MS media supplemented with various plant hormones at the 7th day after pollination. Two mature embryos were obtained from 750 pollinated ovaries cultured in vitro. The percentage of seed set was 0.26%. The mature embryos were transferred onto the MS media supplemented with 2.0 mg/L 6-BA + 0.1 mg/L NAA, and a compound bud was produced later. The compound bud was then cut into a number of single buds, which were transferred onto fresh media. Twenty-two plantlets in vitro were developed from the above single buds. The hybrid plants (F-1) were basically intermediate between the two parents in many,characters with a few showing hybrid vigor. The fertility of hybrid plants (F-1) was poor. Cytological studies revealed that the hybrid plants (F-1) were mixoploid. in nature. The chromosome number of many somatic cells was 2n = 26, which was the sum of the chromosome number of the two parents. The chromosome number of other somatic cells was 2n = 38, similar to that of B. napus. The hybrid offspring (F-2) from the selfed hybrid plants (F-1) showed polymorphism. Among the hybrid offspring (F-2) some were nearly matroclinous and fertile, similar to B. napus. some others were intermediate between the two parents and less fertile, and a few were poorly developed and nearly infertile. From the hybrid offspring a few plants with improved seed-oil quality were obtained.展开更多
To investigate the expression profile of maize genes induced by submergence, a subtracted cDNA library of maize seedling roots was constructed using suppression subtractive hybridization (SSH). The cDNA of maize seedl...To investigate the expression profile of maize genes induced by submergence, a subtracted cDNA library of maize seedling roots was constructed using suppression subtractive hybridization (SSH). The cDNA of maize seedling roots treated with submergence (ST) was used as tester and what from untreated roots (UT) as driver. Products of the secondary PCR from the forward subtraction were cloned into T/A vector and transferred into Escherichia coli strain JM10B by electroporation. Four hundred and eight randomly chosen transformants carrying cDNA fragments were screened with PCR-Select Deferential Screening Kit. One hundred and eighty-four cDNA clones were identified as, submergence specifically induced or highly expressed. After sequencing and removing redundant cDNAs, we got 95 submergence-induced cDNA clones. Of the 95 cDNA clones, 68 contain the regions with 60%-90% identity to their homolog in GenBank, 21 are expected to be novel genes, only 6 correspond to the published maize sequences.展开更多
The distribution of repetitive DNAs along chromosomes is one of the crucial elements for understanding the organization and the evolution of plant genomes. Using a modified genomic in situ hybridization （GISH） proce...The distribution of repetitive DNAs along chromosomes is one of the crucial elements for understanding the organization and the evolution of plant genomes. Using a modified genomic in situ hybridization （GISH） procedure, fluorescence in situ hybridization （FISH） with genomic DNA to their own chromosomes （called self-genomic in situ hybridization, self-GISH） was carried out in six selected plant species with different genome size and amount of repetitive DNA. Nonuniform distribution of the fluorescent labeled probe DNA was observed on the chromosomes of all the species that were tested. The signal patterns varied among species and were related to the genome size. The chromosomes of the small Arabidopsis genome were labeled almost only in the pericentromeric regions and the nucleolus organizer regions （NORs）. The signals in the relatively small genomes, rice, sorghum, and Brassica oleracea var. capitata L., were dispersed along the chromosome lengths, with a predominant distribution in the pericentromeric or proximal regions and some heterochromatic arms. All chromosomes of the large genomes, maize and barley, were densely labeled with strongly labeled regions and weakly labeled or unlabeled regions being arranged alternatively throughout the lengths. In addition, enhanced signal bands were shown in all pericentromeres and the NORs in B. oleracea var. capitata, and in all pericentromeric regions and certain intercalary sites in barley. The enhanced signal band pattern in barley was found consistent with the N-banding pattern of this species. The GISH with self-genomic DNA was compared with FISH with Cot-1 DNA in rice, and their signal patterns are found to be basically consistent. Our results showed that the self-GISH signals actually reflected the hybridization of genomic repetitive DNAs to the chromosomes, thus the self-GISH technique would be useful for revealing the distribution of the regions where repetitive DNAs concentrate along chromosomes and some chromatin differentiation associated with repetitive DNAs in plants.展开更多
The technique of producing doublehaploid of wheat by distant hybridization between wheat and maize has characterized with better inducing effect, shorter in- ducing period, easy operation, and so on. At present, it is...The technique of producing doublehaploid of wheat by distant hybridization between wheat and maize has characterized with better inducing effect, shorter in- ducing period, easy operation, and so on. At present, it is the most efficient and has great potential of application in breeding of wheat. This article reviewed princi- ple and production process of the technique, research situation of the three key in- dicators of the technology（embryo rate, seedling rate and success rate of doubling）in recent years, and application of the technology in breeding, genetics, germplasm improvement of wheat. At last, both the achievements and the direction of further improvement and development of the technology in our program were discussed.展开更多
Phosphorus is one of the three essential macroelements for plant growth. Plants respond to phosphorus starvation through adaptive mechanisms involved in morphological, biochemical and molecular changes. To investigate...Phosphorus is one of the three essential macroelements for plant growth. Plants respond to phosphorus starvation through adaptive mechanisms involved in morphological, biochemical and molecular changes. To investigate the molecular background of the adaptive mechanisms, the suppression subtractive hybridization (SSH) method was used to construct a rice phosphorus-starvation ( Pi-starvation) induced cDNA library. Through screening of the cDNA library and sequencing of the enriched cDNAs, 18 known genes and 47 novel genes were identified. The known genes are involved in different metabolic processes, including phosphate uptake and transport, signal transduction, protein synthesis and degradation, carbon metabolism and stress response. Northern analysis was performed to detect the expression patterns of some known genes and novel genes under different phosphorus levels. Different expression patterns of the selected genes were identified, which suggests that genes involved in different pathways may have different responses to Pi-starvation.展开更多
To understand the inter-hybridization between Cucumis ssp.plants,we used 150 melon varieties as female parents to cross with Cucumis metuliferus and Cucumis anguria.Only melon accessions V2 and V129 set fruits,but see...To understand the inter-hybridization between Cucumis ssp.plants,we used 150 melon varieties as female parents to cross with Cucumis metuliferus and Cucumis anguria.Only melon accessions V2 and V129 set fruits,but seeds from fruits V2（V129）×C.metuliferus were abortive.A few of seeds from the bottom of fruit V2（V129）×C.anguria were fertile.Sequence-related amplified polymorphism（SRAP）molecular markers were used to analyze the progenies of inter-specific hybridization between C.anguria and melon V129.One pair primer（E14/M2）was found effective in amplification on male parent characteristic bands from the hybrids,suggesting that some DNA exchange had happened between C.anguria and melon V129.This study provided data for analyzing the mechanism of inter-hybridization between Cucumis plants.展开更多
[Objective] The aim was to explore salt-resistant Spartina alterniflora and high-yield rice with germplasm resource in order to create new salt-resistant rice species with dual-purpose of food and forage. [Method] Fro...[Objective] The aim was to explore salt-resistant Spartina alterniflora and high-yield rice with germplasm resource in order to create new salt-resistant rice species with dual-purpose of food and forage. [Method] From 2009 to 2011, re- searches on distant hybridization of Spartina alterniflora and Oryza Sativa have been conducted with method of distant hybridization breeding. On the other hand, break- through and combination techniques （four selected one） were adopted to find the new rice species, including techniques of planting and selection in seashore, cyto- logical detection and selection, phenotype selection of backcross, and molecular marker assisted selection. [Result] Success rate of distant hybridization from 2009 to 2010 was 1.39%. RAPD molecular identification of 7C14 and rice female parent of Zhongxiang No.l, seed 2 was carried on with distant hybridization of male parent of Spartina altemiflora （H）. The results showed that bands same with Spartina alterni- flora parents were found in RH-1-10K205-7C14xH, RH-2-8K157-7C14xH, and RH-13- 9H5-Zhongxaing No.1 xH. Considering absent situation in rice parents, distant hy- bridization strains above were found with same parental genetic element as Spartina alterniflora. Female parent of rice 7K339, however, was under RAPD molecular identification with male parent of Spartina alterniflora. The result showed that bands same with Spartina alterniflora parents were found in RH-5-10K215, RH-6-8K48, RH- 12-9H9, RH-14-9H8 and RH-16-9H28. Considering absent situation in rice parents, distant hybridization strains above were found with same parental genetic element as Spartina altemiflora. Rest hybrid strains were found variance with Spartina alterniflora parents and rice parents in varying degrees. [Conclusion] New and excellent rice species of dual-purpose solves problem not only about salt-resistant species badly needed in coastal development and treatment of saline and alkaline land, but about fine fodder and roughage for herbivore, as well. What＇s more, this is of scientific significance in recourse utilization, efficiency improvement in agriculture, food security, and cultivation strategy.展开更多
The genus Oryza consists of two cultivated species (O. sativa L. and O. glaberrima Steud.) and approximately 20 wild relative species widely distributed in the pan-tropics. These species have been classified into four...The genus Oryza consists of two cultivated species (O. sativa L. and O. glaberrima Steud.) and approximately 20 wild relative species widely distributed in the pan-tropics. These species have been classified into four complexes following the Vaughan's taxonomic system([1]). The O. officinalis complex is the largest complex in the genus, which includes ten species, having BE, CC, on, and EE genomes in the diploids as well as BBCC and CCDD genomes in the tetraploids. The relationships among the BE, CC, and EE genomes still remain unclear, although previous studies have indicated certain affinities of these genomes([2-4]). Genomic in situ hybridization (GISH) is a powerful technique to detect the relationships among the related genomes at chromosome and DNA levels. The objective of the present study was to investigate the relationships among the BE, CC and EE genomes in the genus Oryza by the two-probe GISH.展开更多
An intergeneric artificial hybridization was conducted between Cunninghamia R. Br. and Cryptomeria D.Don The results are as follows:1. A considerable number of hybrid seeds shed from 76 pollinated cones were ...An intergeneric artificial hybridization was conducted between Cunninghamia R. Br. and Cryptomeria D.Don The results are as follows:1. A considerable number of hybrid seeds shed from 76 pollinated cones were empty and a total of 628 looks plump. Soft X ray radiographs showed that, still and all, a majority of the “plump" seeds were embryoless (597, 95.6%) whereas some were partially developed (17,2.7%) and only a few were really full (14, 2.2%). 2. Germination test showed that all of the radiographed hybrid seeds with fully developed embryos were germinable whereas those with partially developed embryos were ungerminable. 3. Physiologically, the growth rate of hypocotyl, the date for shedding of seed coat and spreading of cotyledons, the elongation of epicotyl, and the branching of shoot of the 11 month old seedlings showed a tendency to fall behind those of the female parent; morphologically, the 11 month old hybrid seedlings with linear leaves appeared rather short, slender and weak, whereas the seedlings of the female parents with linear_lanceolate leaves appeared rather tall, stout and strong. 4. It is considered that the hybrid may be true and the crossability reveals a close phylogenetic affinity of Cunninghamia with Cryptomeria.展开更多
Hybridization is a driving force in ecological transitions and speciation,yet direct evidence linking it to adaptive differentiation in natural systems remains limited.This study evaluates the role of hybridization in...Hybridization is a driving force in ecological transitions and speciation,yet direct evidence linking it to adaptive differentiation in natural systems remains limited.This study evaluates the role of hybridization in the speciation of Pinus densata,a keystone forest species on the southeastern Tibetan Plateau.By creating artificialinterspecificF1s and a long-term common garden experiment on the plateau,we provide in situ assessments on 44 growth and physiological traits across four seasons,along with RNA sequencing.We found significantphenotypic divergence between P.densata and its putative parental species P.tabuliformis and P.yunnanensis,with P.densata demonstrating superior growth and dynamic balance between photosynthesis and photoprotection.The F1s closely resembled P.densata in most traits.Gene expression revealed 19%–10%of 34,000 examined genes as differentially expressed in P.densata and F1s relative to mid-parent expression values.Both additive(4%)and non-additive gene actions(5%–6%in F1s,10%–12%in P.densata)were common,while transgressive expression occurred more frequently in the stabilized natural hybrids,illustrating transcriptomic reprogramming brought by hybridization and further divergence by natural selection.We provide compelling evidence for hybridization-derived phenotypic divergence at both physiological and gene expression levels that could have contributed to the adaptation of P.densata to high plateau habitat where both parental species have low fitness.The altered physiology and gene expression in hybrids serve both as a substrate for novel ecological adaptation and as a mechanism for the initiation of reproductive isolation.展开更多
Linkers were assembled on a glass surface based on the hydrolysis and condensation of 3-glycidoxy￣propyltrimethoxysilane (GPS). After the assembly of GPS, four approaches were tried to open the ending epoxide group o...Linkers were assembled on a glass surface based on the hydrolysis and condensation of 3-glycidoxy￣propyltrimethoxysilane (GPS). After the assembly of GPS, four approaches were tried to open the ending epoxide group of GPS or to further elongate the linkers. The effect of these approaches on DNA in situ synthesis and hybridization was investigated. For the spacing of the synthesis initiation sites, the wettability of the support and the length of the linking group that attaches the initiation site to the surface have direct influences on the yield of coupling reactions and the subsequent hybridization events. X-ray photoelectron spectroscopy (XPS) and mean contact angles of deionized water of the above slides were measured to assess the linker's characteristics in each procedure. It was proved that the glass slides were successfully modified and became excellent supports for the oligonucleotides synthesis. In addition, it proved best for the in situ oligonucleotides synthesis that a glass slide was in turn treated with ethylenediamine, glutaradehyde, ethanolamine and sodium borohydride solution at ambient temperature after silanized with GPS.展开更多
[Objective] This study aimed to explore the germplasm resources of salt-tolerant Spartina,sweet-stalk Soughum bicolor and high-yield Oryza sativa for innovation of new germplasms of salt-tolerant and sweet-stalk Oryza...[Objective] This study aimed to explore the germplasm resources of salt-tolerant Spartina,sweet-stalk Soughum bicolor and high-yield Oryza sativa for innovation of new germplasms of salt-tolerant and sweet-stalk Oryza sativa with dual purpose of food and forage in sea beach.[Method] From 2009 to 2012,researches on distant hybridization of Spartina,Soughum bicolor and Oryza sativa had been carried out,and the RAPD molecular identification of obtained distant hybridization materials had been conducted.[Result] Experimental evidences of hybrid seed setting,transplanting and economic characters of hybrid materials were obtained;among the 14 hybrid materials for RAPD analysis,5 materials shared common bands with Spartina and Soughum bicolor parents,which were absent in Oryza sativa parent,indicating that the genetic component of Spartina and Soughum bicolor parents has been integrated into the 5 distant hybrids.[Conclusion] This study has important scientific significance in recourse utilization,agricultural efficiency improvement,food security,and cultivation strategy of China,showing broad application prospects.展开更多
Rehybridization of electronic orbitals in carbon nanotubes contains tilting angles of π orbital, electrons wavefunctions of π orbital and a orbital, degrees of hybridization, etc. In this paper, we have obtained ana...Rehybridization of electronic orbitals in carbon nanotubes contains tilting angles of π orbital, electrons wavefunctions of π orbital and a orbital, degrees of hybridization, etc. In this paper, we have obtained analytical formulas of tilting angle of π orbital relative to tube surface, electrons wavefunctions of π orbital and a orbital, degrees of hybridization, separately, as well as the numerical results.展开更多
Potato spindle tuber viroid(PSTVd)disease is one of the major diseases that threatens potato production.Therefore,an advanced,rapid and sensitive detection technology is needed to detect the disease for better control...Potato spindle tuber viroid(PSTVd)disease is one of the major diseases that threatens potato production.Therefore,an advanced,rapid and sensitive detection technology is needed to detect the disease for better control.In order to establish an easier nucleic acid spot hybridization(NASH)method,some studies were tried as the followings:(1)the pre-hybridization step of nucleic acid spot hybridization(NASH)was omitted compared with ordinary way;(2)RNA extraction(phenol extraction and Ames buffer extraction)methods were compared;(3)fixed RNA by UV lamp and oven compared with UV cross-linker;(4)hybridized the RNA in shaking incubator and so on.The results showed that RNA extracted by Ames buffer was more effective than by the phenol extraction method.Besides,the result of hybridization without pre-hybridization step was better than that with 1.5 h of pre-hybridization.The more important discovery was that the shaking incubator could replace the hybridization oven and the ordinary UV lamp could replace the UV cross-linker.After a long term repeated research and testing,a new hybridization system that could rapidly detect the PSTVd by improved NASH technique merely using common instruments and equipment was established.展开更多
基金supported by the National Key R&D Program of China(Grant No.2022YFA1402902)the National Natural Science Foundation of China(Grant Nos.12374179,12074119,12374145,051B22001,12104157,12134003,and 12304218)the Shanghai Pujiang Program(Grant No.23PJ1402200).
文摘The hybridization between oxygen 2p and transition-metal 3d states largely determines the electronic structure near the Fermi level and related functionalities of transition-metal oxides(TMOs).Considerable efforts have been made to manipulate the p-d hybridization in TMOs by tailoring the spatial orbital overlap via structural engineering.Here,we demonstrate enhanced p-d hybridization in Ba^(2+)-doped LaNiO_(3)epitaxial films by simultaneously modifying both the spatial and energetic overlaps between the O-2p and Ni-3d orbitals.Combining x-ray absorption spectroscopy and firstprinciples calculations,we reveal that the enhanced hybridization stems from the synergistic effects of a reduced chargetransfer energy due to hole injection and an increased spatial orbital overlap due to straightening of Ni-O-Ni bonds.We further show that the enhanced p-d hybridization can be utilized to promote the oxygen evolution activity of LaNiO_(3).This work sheds new insights into the fine-tuning of the electronic structures of TMOs for enhanced functionalities.
基金supported by Guangzhou Development Zone Science and Technology(2021GH10,2020GH10,2023GH02)the University of Macao(MYRG2022-00271-FST)The Science and Technology Development Fund(FDCT)of Macao(0032/2022/A).
文摘Introduction Early cancer detection represents a critical evolution in healthcare,addressing a significant pain point in cancer treatment:the tendency for diagnoses to occur at advanced stages.Traditionally,many cancers are not identified until they have progressed to late stages,where treatment options become limited,less effective,and more costly.This late detection results in poorer prognoses,higher mortality rates,and increased healthcare costs.Without early detection tools like Fluorescence In Situ Hybridization(FISH),these challenges persist,leaving patients with fewer opportunities for successful outcomes.
基金supported by the National Natural Science Foundation of China(No.32161143024,31970405)Iran National Science Foundation,Iran-China(INSF-NSFC)joint project(No.4002006).
文摘The biological species concept defines species as groups of actually or potentially interbreeding natural populations that are reproductively isolated from other such groups(Mayr,1942).Reproductive isolation,whether prezygotic or postzygotic,plays a central role in maintaining species boundaries.However,hybridization between closely related taxa can challenge these boundaries and provide insight into speciation,gene flow,and evolutionary processes(Coyne and Orr,2004).
文摘Photocatalytic hydrogen(H_(2))production using solar energy is a cutting-edge green technology that holds great potential for addressing the urgent fuel and environmental crises[1–3].To achieve high-efficiency H_(2) production,cocatalyst modification is commonly employed to provide active sites for the hydrogen evolution reaction(HER)[4,5].In this context,the kinetics of hydrogen adsorption and desorption at these active sites play a crucial role in enhancing overall photocatalytic H_(2) production efficiency.However,the H adsorption/desorption kinetics often exhibit a trade-off,presenting a significant challenge in achieving an optimal equilibrium between Hads and Hdes in many cocatalyst systems.Therefore,fine-tuning the active sites to optimize the H_(2) evolution kinetics is essential for improving photocatalytic activity[6].
基金financial support of the National Natural Science Foundation of China (22379063)
文摘Layered double hydroxides(LDHs)are potential cathode materials for aqueous magnesium-ion batteries(AMIBs).However,the low capacity and sluggish kinetics significantly limit their electrochemical performance in AMIBs.Herein,we find that oxygen vacancies can significantly boost the capacity,electrochemical kinetics,and structure stability of LDHs.The corresponding structure-performance relationship and energy storage mechanism are elaborated through exhaustive in/ex-situ experimental characterizations and density functional theory(DFT)calculations.Specially,in-situ Raman and DFT calculations reveal that oxygen vacancies elevate orbital energy of O 2p and electron density of O atoms,thereby enhancing the orbital hybridization of O 2p with Ni/Co 3d.This facilitates electron transfer between O and adjacent Ni/Co atoms and improves the covalency of Ni–O and Co–O bonds,which activates Ni/Co atoms to release more capacity and stabilizes the Ov-NiCo-LDH structure.Moreover,the distribution of relaxation times(DRT)and molecular dynamics(MD)simulations disclose that the enhanced d-p orbital hybridization optimizes the electronic structure of Ov-NiCo-LDH,which distinctly reduces the diffusion energy barriers of Mg^(2+)and improves the charge transfer kinetics of Ov-NiCo-LDH.Consequently,the assembled Ov-NiCo-LDH//active carbon(AC)and Ov-NiCo-LDH//perylenediimide(PTCDI)AMIBs can both deliver high specific discharge capacity(182.7 and 59.4 mAh g^(−1)at 0.5 A g^(−1),respectively)and long-term cycling stability(85.4%and 89.0%of capacity retentions after 2500 and 2400 cycles at 1.0 A g^(−1),respectively).In addition,the practical prospects for Ov-NiCo-LDH-based AMIBs have been demonstrated in different application scenarios.This work not only provides an effective strategy for obtaining high-performance cathodes of AMIBs,but also fundamentally elucidates the inherent mechanisms.
文摘Asymmetric single-atom catalysts(ASACs)have attracted much attention owing to their excellent catalytic properties.However,the relationship between asymmetric coordination and the spin states of metal sites remains unclear.Additionally,the modulation of reactive oxygen species in Fenton-like reactions remains challenging.Herein,a novel strategy is reported for the rational design of highly loaded Co ASACs(CoN_(1)C_(2)/C_(2)N)immobilized on three-dimensional flower-like C_(2)N using an in situ-generated carbon defect method.In particular,the asymmetrically tricoordinated CoN_(1)C_(2)/C_(2)N exhibited excellent catalytic activity for sulfachloropyridazine degradation,with a turnover frequency of 36.8 min^(–1).Experimental results and theoretical calculations revealed that the electron spin state of the Co-active sites was transferred from the low-spin configuration(t_(2g)^(6)e_(g)^(1))to the high-spin configuration(t_(2g)^(5)e_(g)^(2))owing to asymmetric coordination.The high-spin Co 3d orbital in CoN_(1)C_(2)/C_(2)N possessed more unpaired electrons and therefore,had a strong ability to gain electrons from the O 2p orbitals of HSO_(5)^(–),boosting d-p orbital hybridization.More importantly,the spin-electron filling in theσ^(*)orbital of high-spin Co 3d−O 2p accelerated the desorption of^(*)SO_(5)•^(−),which acted as a rate-limiting step in the reaction,thus facilitating more^(1)O_(2)generation.This study provides an innovative synthetic route for practical ASACs and clarifies the critical relationship between structure and spin state,paving the way for advancements in environmental remediation and energy conversion applications.
文摘The intergeneric hybridization between Brassica napus L. cv. oro and Matthiola incana (L.) R. Br. was carried out to study the phytogenetic peculiarities of the hybrid plants. In order to improve the oil quality of rape seed, ovaries of B. napus pollinated with pollen of M. incana, were cut off and inoculated onto MS media supplemented with various plant hormones at the 7th day after pollination. Two mature embryos were obtained from 750 pollinated ovaries cultured in vitro. The percentage of seed set was 0.26%. The mature embryos were transferred onto the MS media supplemented with 2.0 mg/L 6-BA + 0.1 mg/L NAA, and a compound bud was produced later. The compound bud was then cut into a number of single buds, which were transferred onto fresh media. Twenty-two plantlets in vitro were developed from the above single buds. The hybrid plants (F-1) were basically intermediate between the two parents in many,characters with a few showing hybrid vigor. The fertility of hybrid plants (F-1) was poor. Cytological studies revealed that the hybrid plants (F-1) were mixoploid. in nature. The chromosome number of many somatic cells was 2n = 26, which was the sum of the chromosome number of the two parents. The chromosome number of other somatic cells was 2n = 38, similar to that of B. napus. The hybrid offspring (F-2) from the selfed hybrid plants (F-1) showed polymorphism. Among the hybrid offspring (F-2) some were nearly matroclinous and fertile, similar to B. napus. some others were intermediate between the two parents and less fertile, and a few were poorly developed and nearly infertile. From the hybrid offspring a few plants with improved seed-oil quality were obtained.
文摘To investigate the expression profile of maize genes induced by submergence, a subtracted cDNA library of maize seedling roots was constructed using suppression subtractive hybridization (SSH). The cDNA of maize seedling roots treated with submergence (ST) was used as tester and what from untreated roots (UT) as driver. Products of the secondary PCR from the forward subtraction were cloned into T/A vector and transferred into Escherichia coli strain JM10B by electroporation. Four hundred and eight randomly chosen transformants carrying cDNA fragments were screened with PCR-Select Deferential Screening Kit. One hundred and eighty-four cDNA clones were identified as, submergence specifically induced or highly expressed. After sequencing and removing redundant cDNAs, we got 95 submergence-induced cDNA clones. Of the 95 cDNA clones, 68 contain the regions with 60%-90% identity to their homolog in GenBank, 21 are expected to be novel genes, only 6 correspond to the published maize sequences.
基金This work was supported by the National Natural Sciences Foundation of China (No. 39870423).
文摘The distribution of repetitive DNAs along chromosomes is one of the crucial elements for understanding the organization and the evolution of plant genomes. Using a modified genomic in situ hybridization （GISH） procedure, fluorescence in situ hybridization （FISH） with genomic DNA to their own chromosomes （called self-genomic in situ hybridization, self-GISH） was carried out in six selected plant species with different genome size and amount of repetitive DNA. Nonuniform distribution of the fluorescent labeled probe DNA was observed on the chromosomes of all the species that were tested. The signal patterns varied among species and were related to the genome size. The chromosomes of the small Arabidopsis genome were labeled almost only in the pericentromeric regions and the nucleolus organizer regions （NORs）. The signals in the relatively small genomes, rice, sorghum, and Brassica oleracea var. capitata L., were dispersed along the chromosome lengths, with a predominant distribution in the pericentromeric or proximal regions and some heterochromatic arms. All chromosomes of the large genomes, maize and barley, were densely labeled with strongly labeled regions and weakly labeled or unlabeled regions being arranged alternatively throughout the lengths. In addition, enhanced signal bands were shown in all pericentromeres and the NORs in B. oleracea var. capitata, and in all pericentromeric regions and certain intercalary sites in barley. The enhanced signal band pattern in barley was found consistent with the N-banding pattern of this species. The GISH with self-genomic DNA was compared with FISH with Cot-1 DNA in rice, and their signal patterns are found to be basically consistent. Our results showed that the self-GISH signals actually reflected the hybridization of genomic repetitive DNAs to the chromosomes, thus the self-GISH technique would be useful for revealing the distribution of the regions where repetitive DNAs concentrate along chromosomes and some chromatin differentiation associated with repetitive DNAs in plants.
文摘The technique of producing doublehaploid of wheat by distant hybridization between wheat and maize has characterized with better inducing effect, shorter in- ducing period, easy operation, and so on. At present, it is the most efficient and has great potential of application in breeding of wheat. This article reviewed princi- ple and production process of the technique, research situation of the three key in- dicators of the technology（embryo rate, seedling rate and success rate of doubling）in recent years, and application of the technology in breeding, genetics, germplasm improvement of wheat. At last, both the achievements and the direction of further improvement and development of the technology in our program were discussed.
文摘Phosphorus is one of the three essential macroelements for plant growth. Plants respond to phosphorus starvation through adaptive mechanisms involved in morphological, biochemical and molecular changes. To investigate the molecular background of the adaptive mechanisms, the suppression subtractive hybridization (SSH) method was used to construct a rice phosphorus-starvation ( Pi-starvation) induced cDNA library. Through screening of the cDNA library and sequencing of the enriched cDNAs, 18 known genes and 47 novel genes were identified. The known genes are involved in different metabolic processes, including phosphate uptake and transport, signal transduction, protein synthesis and degradation, carbon metabolism and stress response. Northern analysis was performed to detect the expression patterns of some known genes and novel genes under different phosphorus levels. Different expression patterns of the selected genes were identified, which suggests that genes involved in different pathways may have different responses to Pi-starvation.
基金Supported by Special Basic Research Fund for Central Public Research Institutes(0032011018)~~
文摘To understand the inter-hybridization between Cucumis ssp.plants,we used 150 melon varieties as female parents to cross with Cucumis metuliferus and Cucumis anguria.Only melon accessions V2 and V129 set fruits,but seeds from fruits V2（V129）×C.metuliferus were abortive.A few of seeds from the bottom of fruit V2（V129）×C.anguria were fertile.Sequence-related amplified polymorphism（SRAP）molecular markers were used to analyze the progenies of inter-specific hybridization between C.anguria and melon V129.One pair primer（E14/M2）was found effective in amplification on male parent characteristic bands from the hybrids,suggesting that some DNA exchange had happened between C.anguria and melon V129.This study provided data for analyzing the mechanism of inter-hybridization between Cucumis plants.
基金Supported by National Natural Science Foundation of China(31072064)Foundation Project of Self-reliant Innovation for Agricultural Science and Technology,Supporting Project for Exploration and Research of Jiangsu Province in2011(TCX(11)4133,CX(11)4060)~~
文摘[Objective] The aim was to explore salt-resistant Spartina alterniflora and high-yield rice with germplasm resource in order to create new salt-resistant rice species with dual-purpose of food and forage. [Method] From 2009 to 2011, re- searches on distant hybridization of Spartina alterniflora and Oryza Sativa have been conducted with method of distant hybridization breeding. On the other hand, break- through and combination techniques （four selected one） were adopted to find the new rice species, including techniques of planting and selection in seashore, cyto- logical detection and selection, phenotype selection of backcross, and molecular marker assisted selection. [Result] Success rate of distant hybridization from 2009 to 2010 was 1.39%. RAPD molecular identification of 7C14 and rice female parent of Zhongxiang No.l, seed 2 was carried on with distant hybridization of male parent of Spartina altemiflora （H）. The results showed that bands same with Spartina alterni- flora parents were found in RH-1-10K205-7C14xH, RH-2-8K157-7C14xH, and RH-13- 9H5-Zhongxaing No.1 xH. Considering absent situation in rice parents, distant hy- bridization strains above were found with same parental genetic element as Spartina alterniflora. Female parent of rice 7K339, however, was under RAPD molecular identification with male parent of Spartina alterniflora. The result showed that bands same with Spartina alterniflora parents were found in RH-5-10K215, RH-6-8K48, RH- 12-9H9, RH-14-9H8 and RH-16-9H28. Considering absent situation in rice parents, distant hybridization strains above were found with same parental genetic element as Spartina altemiflora. Rest hybrid strains were found variance with Spartina alterniflora parents and rice parents in varying degrees. [Conclusion] New and excellent rice species of dual-purpose solves problem not only about salt-resistant species badly needed in coastal development and treatment of saline and alkaline land, but about fine fodder and roughage for herbivore, as well. What＇s more, this is of scientific significance in recourse utilization, efficiency improvement in agriculture, food security, and cultivation strategy.
文摘The genus Oryza consists of two cultivated species (O. sativa L. and O. glaberrima Steud.) and approximately 20 wild relative species widely distributed in the pan-tropics. These species have been classified into four complexes following the Vaughan's taxonomic system([1]). The O. officinalis complex is the largest complex in the genus, which includes ten species, having BE, CC, on, and EE genomes in the diploids as well as BBCC and CCDD genomes in the tetraploids. The relationships among the BE, CC, and EE genomes still remain unclear, although previous studies have indicated certain affinities of these genomes([2-4]). Genomic in situ hybridization (GISH) is a powerful technique to detect the relationships among the related genomes at chromosome and DNA levels. The objective of the present study was to investigate the relationships among the BE, CC and EE genomes in the genus Oryza by the two-probe GISH.
文摘An intergeneric artificial hybridization was conducted between Cunninghamia R. Br. and Cryptomeria D.Don The results are as follows:1. A considerable number of hybrid seeds shed from 76 pollinated cones were empty and a total of 628 looks plump. Soft X ray radiographs showed that, still and all, a majority of the “plump" seeds were embryoless (597, 95.6%) whereas some were partially developed (17,2.7%) and only a few were really full (14, 2.2%). 2. Germination test showed that all of the radiographed hybrid seeds with fully developed embryos were germinable whereas those with partially developed embryos were ungerminable. 3. Physiologically, the growth rate of hypocotyl, the date for shedding of seed coat and spreading of cotyledons, the elongation of epicotyl, and the branching of shoot of the 11 month old seedlings showed a tendency to fall behind those of the female parent; morphologically, the 11 month old hybrid seedlings with linear leaves appeared rather short, slender and weak, whereas the seedlings of the female parents with linear_lanceolate leaves appeared rather tall, stout and strong. 4. It is considered that the hybrid may be true and the crossability reveals a close phylogenetic affinity of Cunninghamia with Cryptomeria.
基金supported by the National Natural Science Foundation of China(32171816)T4F program Sweden.
文摘Hybridization is a driving force in ecological transitions and speciation,yet direct evidence linking it to adaptive differentiation in natural systems remains limited.This study evaluates the role of hybridization in the speciation of Pinus densata,a keystone forest species on the southeastern Tibetan Plateau.By creating artificialinterspecificF1s and a long-term common garden experiment on the plateau,we provide in situ assessments on 44 growth and physiological traits across four seasons,along with RNA sequencing.We found significantphenotypic divergence between P.densata and its putative parental species P.tabuliformis and P.yunnanensis,with P.densata demonstrating superior growth and dynamic balance between photosynthesis and photoprotection.The F1s closely resembled P.densata in most traits.Gene expression revealed 19%–10%of 34,000 examined genes as differentially expressed in P.densata and F1s relative to mid-parent expression values.Both additive(4%)and non-additive gene actions(5%–6%in F1s,10%–12%in P.densata)were common,while transgressive expression occurred more frequently in the stabilized natural hybrids,illustrating transcriptomic reprogramming brought by hybridization and further divergence by natural selection.We provide compelling evidence for hybridization-derived phenotypic divergence at both physiological and gene expression levels that could have contributed to the adaptation of P.densata to high plateau habitat where both parental species have low fitness.The altered physiology and gene expression in hybrids serve both as a substrate for novel ecological adaptation and as a mechanism for the initiation of reproductive isolation.
文摘Linkers were assembled on a glass surface based on the hydrolysis and condensation of 3-glycidoxy￣propyltrimethoxysilane (GPS). After the assembly of GPS, four approaches were tried to open the ending epoxide group of GPS or to further elongate the linkers. The effect of these approaches on DNA in situ synthesis and hybridization was investigated. For the spacing of the synthesis initiation sites, the wettability of the support and the length of the linking group that attaches the initiation site to the surface have direct influences on the yield of coupling reactions and the subsequent hybridization events. X-ray photoelectron spectroscopy (XPS) and mean contact angles of deionized water of the above slides were measured to assess the linker's characteristics in each procedure. It was proved that the glass slides were successfully modified and became excellent supports for the oligonucleotides synthesis. In addition, it proved best for the in situ oligonucleotides synthesis that a glass slide was in turn treated with ethylenediamine, glutaradehyde, ethanolamine and sodium borohydride solution at ambient temperature after silanized with GPS.
基金Supported by Natural Science Foundation of Jiangsu Province"Exploration and Innovation of Salt-tolerant and Sweet-stalk Rice Germplasm Resources with Dual Purpose of Food and Forage in Sea Beach"(BK2010270)Application Research Project from Nantong Municipal Science and Technology Bureau"Study on Molecular Breeding Technology for Salt-tolerant and Sweet-stalk Superior Forage Rice in Sea Beach"(BK2011006)~~
文摘[Objective] This study aimed to explore the germplasm resources of salt-tolerant Spartina,sweet-stalk Soughum bicolor and high-yield Oryza sativa for innovation of new germplasms of salt-tolerant and sweet-stalk Oryza sativa with dual purpose of food and forage in sea beach.[Method] From 2009 to 2012,researches on distant hybridization of Spartina,Soughum bicolor and Oryza sativa had been carried out,and the RAPD molecular identification of obtained distant hybridization materials had been conducted.[Result] Experimental evidences of hybrid seed setting,transplanting and economic characters of hybrid materials were obtained;among the 14 hybrid materials for RAPD analysis,5 materials shared common bands with Spartina and Soughum bicolor parents,which were absent in Oryza sativa parent,indicating that the genetic component of Spartina and Soughum bicolor parents has been integrated into the 5 distant hybrids.[Conclusion] This study has important scientific significance in recourse utilization,agricultural efficiency improvement,food security,and cultivation strategy of China,showing broad application prospects.
基金Project supported by the Specialized Research Fund of Doctoral Program of Higher Education of China (Grant No 20030532008)
文摘Rehybridization of electronic orbitals in carbon nanotubes contains tilting angles of π orbital, electrons wavefunctions of π orbital and a orbital, degrees of hybridization, etc. In this paper, we have obtained analytical formulas of tilting angle of π orbital relative to tube surface, electrons wavefunctions of π orbital and a orbital, degrees of hybridization, separately, as well as the numerical results.
基金Supported by Doctoral Research Startup Project of Zhaotong University。
文摘Potato spindle tuber viroid(PSTVd)disease is one of the major diseases that threatens potato production.Therefore,an advanced,rapid and sensitive detection technology is needed to detect the disease for better control.In order to establish an easier nucleic acid spot hybridization(NASH)method,some studies were tried as the followings:(1)the pre-hybridization step of nucleic acid spot hybridization(NASH)was omitted compared with ordinary way;(2)RNA extraction(phenol extraction and Ames buffer extraction)methods were compared;(3)fixed RNA by UV lamp and oven compared with UV cross-linker;(4)hybridized the RNA in shaking incubator and so on.The results showed that RNA extracted by Ames buffer was more effective than by the phenol extraction method.Besides,the result of hybridization without pre-hybridization step was better than that with 1.5 h of pre-hybridization.The more important discovery was that the shaking incubator could replace the hybridization oven and the ordinary UV lamp could replace the UV cross-linker.After a long term repeated research and testing,a new hybridization system that could rapidly detect the PSTVd by improved NASH technique merely using common instruments and equipment was established.
