Sphingosine-1-phosphate(S1P)is an important lipid mediator that regulates a diverse range of intracellular cell signaling pathways that are relevant to tissue engineering and regenerative medicine.However,the precise ...Sphingosine-1-phosphate(S1P)is an important lipid mediator that regulates a diverse range of intracellular cell signaling pathways that are relevant to tissue engineering and regenerative medicine.However,the precise function of S1P in dental pulp stem cells(DPSCs)and its osteogenic differentiation remains unclear.We here investigated the function of S1P/S1P receptor(S1PR)-mediated cellular signaling in the osteogenic differentiation of DPSCs and clarified the fundamental signaling pathway.Our results showed that S1P-treated DPSCs exhibited a low rate of differentiation toward the osteogenic phenotype in association with a marked reduction in osteogenesis-related gene expression and AKT activation.Of note,both S1PR1/S1PR3 and S1PR2 agonists significantly downregulated the expression of osteogenic genes and suppressed AKT activation,resulting in an attenuated osteogenic capacity of DPSCs.Most importantly,an AKT activator completely abrogated the S1P-mediated downregulation of osteoblastic markers and partially prevented S1P-mediated attenuation effects during osteogenesis.Intriguingly,the pro-inflammatory TNF-αcytokine promoted the infiltration of macrophages toward DPSCs and induced S1P production in both DPSCs and macrophages.Our findings indicate that the elevation of S1P under inflammatory conditions suppresses the osteogenic capacity of the DPSCs responsible for regenerative endodontics.展开更多
Rapid diagnosis of rice bacterial diseases is critical for early warning and precise management during their initial phases.The use of rapid nucleic acid detection on paper-based platforms is an innovative technique t...Rapid diagnosis of rice bacterial diseases is critical for early warning and precise management during their initial phases.The use of rapid nucleic acid detection on paper-based platforms is an innovative technique that offers simplicity,portability,and affordability.However,the temperature dependence of the amplification process and variations in paper device technologies hinder on-site detection of pathogens using paper-based platforms.展开更多
Bone tissue renewal can be enhanced through co-transplantation of bone mesenchymal stem cells(BMSCs)and vascular endothelial cells(ECs).However,there are apparent limitations in stem cell-based therapy which hinder it...Bone tissue renewal can be enhanced through co-transplantation of bone mesenchymal stem cells(BMSCs)and vascular endothelial cells(ECs).However,there are apparent limitations in stem cell-based therapy which hinder its clinic translation.Hence,we investigated the potential of alternative stem cell substitutes for facilitating bone regeneration.In this study,we successfully prepared cell membrane vesicles(CMVs)from BMSCs and ECs.The results showed that BMSC-derived cell membrane vesicles(BMSC-CMVs)possessed membrane receptors involved in juxtacrine signaling and growth factors derived from their parental cells.EC-derived cell membrane vesicles(EC-CMVs)also contained BMP2 and VEGF derived from their parental cells.BMSC-CMVs enhanced tube formation and migration ability of hUVECs,while EC-CMVs promoted the osteogenic differentiation of hBMSCs in vitro.Using a rat skull defect model,we found that co-transplantation of BMSC-CMVs and EC-CMVs could stimulate angiogenesis and bone formation in vivo.Therefore,our research might provide an innovative and feasible approach for cell-free therapy in bone tissue regeneration.展开更多
In this study,a series of hindered urea bond(HUB)containing polyurethane-urea methacrylate prepolymers and a none HUB containing polyurethane methacrylate prepolymer were prepared using isobornyl methacrylate as the r...In this study,a series of hindered urea bond(HUB)containing polyurethane-urea methacrylate prepolymers and a none HUB containing polyurethane methacrylate prepolymer were prepared using isobornyl methacrylate as the reactive diluent via one-pot procedure.The prepolymers were characterized fully by various techniques.Then,their thermosets were fabricated via UV curing in presence of a photo initiator,and their mechanical property and thermal behavior were investigated and compared.Different from the none HUB containing thermoset,the HUB containing thermosets(defined as PUT)could be recycled and reprocessed by hot press under relatively mild conditions with high recovery ratio of mechanical property.Furthermore,zinc oxide(ZnO)nanoparticles were modified with 3-(trimethoxysilyl)propyl methacrylate and the modified ZnO(defined as ZnO-TPM)was dispersed and polymerized into PUT matrix to prepare their nanocomposites.The influence of ZnO-TPM on the mechanical performance of the composites was evaluated,which indicated that the Young’s modulus and tensile strength increased gradually to the maximum values at ZnO-TPM content of 1 wt%and then decreased.The composites also displayed good reprocessability with improved recovery ratio compared to the pure PUT sample.In addition,the composite materials exhibited strong UV absorption capacity,implying their potential application in the circumstance where UV-shielding was required.展开更多
Exploration of exotic phenomena in magnetic topological systems is at the frontier of condensed matter physics,holding a significant promise for applications in topological spintronics.However,complex magnetic structu...Exploration of exotic phenomena in magnetic topological systems is at the frontier of condensed matter physics,holding a significant promise for applications in topological spintronics.However,complex magnetic structures carrying nontrivial topological properties hinder its progresses.Here,we investigate the pressure effect on the novel topological kagome magnets GdV_(6)Sn_(6) and TbV_(6)Sn_(6) to dig out the interplay between magnetic Gd/Tb layers and nonmagnetic V-based kagome sublattice.The pressure-tuned magnetic transition temperature Tm in both the compounds exhibit a turning point at the critical pressure P_(c),accompanied with a sign reversal in anomalous Hall effect(AHE).The separation of intrinsic and extrinsic contributions using the Tian-Ye-Jin scaling model suggests that the intrinsic mechanism originating from the electronic Berry curvature holds the priority in the competition with extrinsic mechanism in AHE.The above-mentioned findings can be attributed to the combined effect of pressure-tuned band topology and magnetic interaction in segregated layers.Our results provide a practical route to design and manipulate the intrinsic AHE in magnetic topological materials.展开更多
Detecting tiny deformations or vibrations, particularly those associated with strains below 1%, is essential in various technological applications. Traditional intrinsic materials, including metals and semiconductors,...Detecting tiny deformations or vibrations, particularly those associated with strains below 1%, is essential in various technological applications. Traditional intrinsic materials, including metals and semiconductors, face challenges in simultaneously achieving initial metallic state and strain-induced insulating state, hindering the development of highly sensitive mechanical sensors. Here we report an ultrasensitive mechanical sensor based on a strain-induced tunable ordered array of metallic and insulating states in the single-crystal bronze-phase vanadium dioxide [VO_(2)(B)] quantum material. It is shown that the initial metallic state in the VO_(2)(B) flake can be tuned to the insulating state by applying a weak uniaxial tensile strain. Such a unique property gives rise to a record-high gauge factor of above 607970, surpassing previous values by an order of magnitude, with excellent linearity and mechanical resilience as well as durability. As a proof-of-concept application, we use our proposed mechanical sensor to demonstrate precise sensing of the micro piece, gentle airflows and water droplets. We attribute the superior performance of the sensor to the strain-induced continuous metal-insulator transition in the single-crystal VO_(2)(B) flake, evidenced by experimental and simulation results. Our findings highlight the potential of exploiting correlated quantum materials for next-generation ultrasensitive flexible mechanical sensors, addressing critical limitations in traditional materials.展开更多
Background:Potassium(K)deficiency has become a common field production problem following the widespread adoption of Bacillus thuringiensis(Bt)transgenic cotton(Gossypium hirsutum L.)worldwide.The purpose of this study...Background:Potassium(K)deficiency has become a common field production problem following the widespread adoption of Bacillus thuringiensis(Bt)transgenic cotton(Gossypium hirsutum L.)worldwide.The purpose of this study was to clarify whether the introduction of Bt gene directly reduces the K-use efficiency of cotton to induce K deficiency.Results:The cotton variety,Jihe 321(wild type,WT)and its two Bt(Cry1Ac)-transgenic overexpression lines(OE-29317,OE 29312)were studied in field with low soil-test K~+(47.8 mg·kg~(-1)).In the field with low soil-test K~+,only OE 29317 had less biomass and K~+accumulation than the WT at some growth stages.Both Bt lines produced similar or even greater seed cotton yield than WT in the field.When the Bt gene(~70%)in OE-29317 and OE-29312 plants was silenced by virus-induced gene silencing(VIGS),the VIGS Bt plants did not produce more biomass than VIGSgreen fluorescent protein(control)plants.Conclusions:The introduction of Bt gene did not necessarily hinder the K use efficiency of the cotton lines under this study.Keywords:Biomass,Bt(Bacillus thuringiensis)gene,Cotton(Gossypium hirsutum L.),K uptake,K utilization index,Yield。展开更多
Environmental Footprints:Analyzing and Mitigating the Environmental Burden from Anthropogenic Activities Introduction With the progress of industrialization and urbanization,anthropogenic activities have led to consid...Environmental Footprints:Analyzing and Mitigating the Environmental Burden from Anthropogenic Activities Introduction With the progress of industrialization and urbanization,anthropogenic activities have led to considerable pres-sure on the Earth,hindering global sustainable development.展开更多
Chinese college students reading in a foreign language seem to read with less understanding and at a considerably slower speed. The factors that hinder Chinese college students' English reading were analyzed at th...Chinese college students reading in a foreign language seem to read with less understanding and at a considerably slower speed. The factors that hinder Chinese college students' English reading were analyzed at the lexical level, the syntactic level,and the discourse level. And then, several reading strategies were recommended to overcome such reading difficulties.展开更多
Simultaneous electrochemical synthesis of high-valueadded chemicals and hydrogen is a promising technology for efficient carbon utilization and renewable energy storage. However, the lack of rational guidance for desi...Simultaneous electrochemical synthesis of high-valueadded chemicals and hydrogen is a promising technology for efficient carbon utilization and renewable energy storage. However, the lack of rational guidance for designing efficient catalysts for electrosynthesis significantly hinders its development.展开更多
Chrysanthemum is frequently attacked by aphids,which greatly hinders the growth and ornamental value of this plant species.WRKY transcription factors play an important role in the response to biotic stresses such as p...Chrysanthemum is frequently attacked by aphids,which greatly hinders the growth and ornamental value of this plant species.WRKY transcription factors play an important role in the response to biotic stresses such as pathogen and insect stresses.Here,chrysanthemum CmWRKY53 was cloned,and its expression was induced by aphid infestation.To verify the role of CmWRKY53 in resistance to aphids,CmWRKY53 transgenic chrysanthemum was generated.CmWRKY53 was found to mediate the susceptibility of chrysanthemum to aphids.The expression levels of secondary metabolite biosynthesis genes,such as peroxidase-and polyphenol oxidase-encoding genes,decreased in CmWRKY53-overexpressing(CmWRKY53-Oe)plants but dramatically increased in chimeric dominant repressor(CmWRKY53-SRDX)plants,suggesting that CmWRKY53 contributes to the susceptibility of chrysanthemum to aphids,possibly due to its role in the regulation of secondary metabolites.展开更多
Over 2 x 10(8) tons of polymers are produced every year, and a large portion of polymers faces the degradation problem. There are many effective methods to protect polymers against degradation and the addition of stab...Over 2 x 10(8) tons of polymers are produced every year, and a large portion of polymers faces the degradation problem. There are many effective methods to protect polymers against degradation and the addition of stabilizers to polymer remains the most convenient and effective way of enhancing polymer life and performance. In this article, a series of effective stabilizers with optimal molecular weight (MW), including common, monomeric and polymeric stabilizers (antioxidant and light stabilizer) were synthesized using isocyanation, controlled isocyanation, hydrosilylation, epoxide addition, macroreaction of stabilizing functional compounds and polymerization of monomeric stabilizers. The structure and performance of these new stabilizers were characterized by using IR, NMR, MS, UV-spectra, XPS and elemental analysis. The current development of stabilizer synthesis was also reviewed.展开更多
Copolymerization of propylene and hindered piperidine monomers was carried out over a high activity supported Ziegler-Natta catalyst, using Al(C2H5)(3) as cocatalyst. Factors which affect the copolymerization were stu...Copolymerization of propylene and hindered piperidine monomers was carried out over a high activity supported Ziegler-Natta catalyst, using Al(C2H5)(3) as cocatalyst. Factors which affect the copolymerization were studied, The copolymers exhibited high light stability without adding extra light stabilizers. A self-stabilized polypropylene was prepared.展开更多
The Chinese longsnout catfish(Leiocassis longirostris Günther)is one of the most economically important freshwater fish in China.As wild populations have declined sharply in recent years,it is also a valuable mod...The Chinese longsnout catfish(Leiocassis longirostris Günther)is one of the most economically important freshwater fish in China.As wild populations have declined sharply in recent years,it is also a valuable model for research on sexual dimorphism,comparative biology,and conservation.However,the current lack of high-quality chromosome-level genome information for the species hinders the advancement of comparative genomic analysis and evolutionary studies.Therefore,we constructed the first high-quality chromosomelevel reference genome for L.longirostris.The total genome was 703.19 Mb,with 389 contigs and contig N50 length of 4.29 Mb.Using high-throughput chromosome conformation capture(Hi-C)data,the genome sequences(685.53 Mb)were scaffolded into 26 chromosomes ranging from 17.36 to 43.97 Mb,resulting in a chromosomal anchoring rate for the genome of 97.44%.In total,23708 protein-coding genes were identified in the genome.Phylogenetic analysis indicated that L.longirostris and its closest related species P.fulvidraco diverged approximately 26.6 million years ago.This highquality reference genome of L.longirostris should pave the way for future genomic comparisons and evolutionary research.展开更多
In this contribution,we reported the preparation of vitrimers by using commodity thermoplastics via post crosslinking with hindered urea bonds(HUBs).First,three hindered urea diisocyanates(HUDIs)were synthesized via t...In this contribution,we reported the preparation of vitrimers by using commodity thermoplastics via post crosslinking with hindered urea bonds(HUBs).First,three hindered urea diisocyanates(HUDIs)were synthesized via the reactions of N,N'-di-tert-butylethylenediamine,N,N'-diethylethylenediamine,and piperazine with isophorone diisocyanate(IPDI).Thereafter,these HUDIs were used as the crosslinking agents to crosslink poly(hydroxyether of bisphenol A)(PH),a commodity thermoplastics.Fourier transform infrared(FTIR)spectroscopy and dynamic mechanical thermal analyses(DMTA)indicated that the PH thermosets were successfully obtained.It was found that the thermosets displayed the behavior of vitrimers.The PH thermosets can be reprocessed at elevated temperature without using catalyst and the mechanical strengths of vitrimers were recovered as high as 95%.The reprocessing properties are attributable to dynamic exchange reaction of hindered urea bonds,contingent on types of hindered urea bonds.展开更多
Norbornene derivatives exo,endo-2-[2-(3,5-di-tert-butyl-4-hydroxyphenoxy)-acetoxy]methyl-5-norbornene(M1) and 3,3,5,5-tetramethyl-4-piperidinyl 5-norbornene-exo,endo-2-carboxylate(M2)were synthesized and polymerized b...Norbornene derivatives exo,endo-2-[2-(3,5-di-tert-butyl-4-hydroxyphenoxy)-acetoxy]methyl-5-norbornene(M1) and 3,3,5,5-tetramethyl-4-piperidinyl 5-norbornene-exo,endo-2-carboxylate(M2)were synthesized and polymerized by RuCl_2(=CHPh)(PCy_3)_2 to prepare a novel kind of bi-functional polymer bearing sterically hindered phenol(SHP)and hindered amine(HLAS)groups via ring-opening metathesis polymerization(ROMP).The resulting copolymers were characterized by gel permeation chromatography(GPC),~1H-NMR and differen...展开更多
In recent years,deep learning has made tremendous achievements in computer vision,natural language processing,man-machine games and so on,where artificial intelligence can reach or go beyond the level of human beings....In recent years,deep learning has made tremendous achievements in computer vision,natural language processing,man-machine games and so on,where artificial intelligence can reach or go beyond the level of human beings.However,behind so many glories,some serious challenges exist in the bottom hardware,hindering the further development of Artificial Intelligence.展开更多
The corrosion of ECR glass fiber was investigated by the analysis methods of weight loss ratio under different acids and at various durations.Weight loss,leaching of cations,and surface composition of ECR glass fiber ...The corrosion of ECR glass fiber was investigated by the analysis methods of weight loss ratio under different acids and at various durations.Weight loss,leaching of cations,and surface composition of ECR glass fiber were analyzed.The corrosion mechanism of ECR glass fiber in acid environment was also discussed.The experimental results showed that the corrosion degree of ECR glass fiber in different acids obeyed the order： HNO3〉H2SO4〉HCl.The acid effects on corrosion of ECR glass fiberis were totally different.Hydrochloric acid mainly destroyed the network structure of [AlO4],while sulfuric acid and nitric acid mainly destroyed the structure of [SiO4].The acid resistance of ECR glass fiber is much better than that of E glass fiber due to the generation of intermediate product silicic acid gel Si（OH）4 during ion exchange.It can adhere to the glass surface to form a thin film and hinder the proceeding of corrosion.展开更多
Self-incompatibility(SI)is a kind of plant fertilization obstacle,which can prevent the harmful effects of inbreeding decline,but it hinders the breeding of inbred lines.Tea plants have SI and long-term cross-pollinat...Self-incompatibility(SI)is a kind of plant fertilization obstacle,which can prevent the harmful effects of inbreeding decline,but it hinders the breeding of inbred lines.Tea plants have SI and long-term cross-pollination,which limits the progress of genetic research and variety improvement.However,the mechanism of SI in tea plants is still a mystery.Herein,microscopic observation showed that the pollen tube could pass through the base of style and enter the ovary cavity after 48 h of self-pollination at different flowering stages,and the SI intensity at bud stage and full bloom stage was lower than initial bloom stage.RNA-seq analysis showed that 1,463 and 1,409 differentially expressed genes(DEGs)were associated with low SI at bud stage and full bloom stage,respectively,and 507 DEGs were associated with SI at initial bloom stage.The results of qRT-PCR validation of 20 DEGs were consistent with the RNA-seq data.Furthermore,CsRNS,CsSRKL5 and CsSRKL8 specifically expressed in style,which may be related to the low SI at bud stage,and three CsACC genes may be related to the low SI at full bloom stage.The results provide useful information for understanding the mechanism of SI in tea plants.展开更多
基金supported by a National Research Foundation of Korea(NRF)MRC grant(2018R1A5A2020732)by a grant of the Basic Science and Engineering Research Program(2018R1A2B2001867)funded by the Korean government to E.J.C.by the Bio&Medical Technology Development Program(NRF2017M3A9E4047243)funded by the Ministry of Science,ICT and Future Planning,the Republic of Korea to H.R.K.
文摘Sphingosine-1-phosphate(S1P)is an important lipid mediator that regulates a diverse range of intracellular cell signaling pathways that are relevant to tissue engineering and regenerative medicine.However,the precise function of S1P in dental pulp stem cells(DPSCs)and its osteogenic differentiation remains unclear.We here investigated the function of S1P/S1P receptor(S1PR)-mediated cellular signaling in the osteogenic differentiation of DPSCs and clarified the fundamental signaling pathway.Our results showed that S1P-treated DPSCs exhibited a low rate of differentiation toward the osteogenic phenotype in association with a marked reduction in osteogenesis-related gene expression and AKT activation.Of note,both S1PR1/S1PR3 and S1PR2 agonists significantly downregulated the expression of osteogenic genes and suppressed AKT activation,resulting in an attenuated osteogenic capacity of DPSCs.Most importantly,an AKT activator completely abrogated the S1P-mediated downregulation of osteoblastic markers and partially prevented S1P-mediated attenuation effects during osteogenesis.Intriguingly,the pro-inflammatory TNF-αcytokine promoted the infiltration of macrophages toward DPSCs and induced S1P production in both DPSCs and macrophages.Our findings indicate that the elevation of S1P under inflammatory conditions suppresses the osteogenic capacity of the DPSCs responsible for regenerative endodontics.
基金supported by the National Natural Science Foundation of China(Grant No.32171895)National Key Research and Development Program for Young Scientists,China(Grant No.2022YFD2000200)Jiangsu Province Key Reserch and Development Program Project,China(Grant No.BE2022052-2).
文摘Rapid diagnosis of rice bacterial diseases is critical for early warning and precise management during their initial phases.The use of rapid nucleic acid detection on paper-based platforms is an innovative technique that offers simplicity,portability,and affordability.However,the temperature dependence of the amplification process and variations in paper device technologies hinder on-site detection of pathogens using paper-based platforms.
基金supported by the National Natural Science Foundation of China(Nos.U22A20160,82221003,81991505,82201123)China Postdoctoral Science Foundation(2022M720290,2021M700279)Hubei Provincial Key Laboratory of Oral and Maxillofacial Development and Regeneration Open Fund(2022kqhm004).
文摘Bone tissue renewal can be enhanced through co-transplantation of bone mesenchymal stem cells(BMSCs)and vascular endothelial cells(ECs).However,there are apparent limitations in stem cell-based therapy which hinder its clinic translation.Hence,we investigated the potential of alternative stem cell substitutes for facilitating bone regeneration.In this study,we successfully prepared cell membrane vesicles(CMVs)from BMSCs and ECs.The results showed that BMSC-derived cell membrane vesicles(BMSC-CMVs)possessed membrane receptors involved in juxtacrine signaling and growth factors derived from their parental cells.EC-derived cell membrane vesicles(EC-CMVs)also contained BMP2 and VEGF derived from their parental cells.BMSC-CMVs enhanced tube formation and migration ability of hUVECs,while EC-CMVs promoted the osteogenic differentiation of hBMSCs in vitro.Using a rat skull defect model,we found that co-transplantation of BMSC-CMVs and EC-CMVs could stimulate angiogenesis and bone formation in vivo.Therefore,our research might provide an innovative and feasible approach for cell-free therapy in bone tissue regeneration.
文摘In this study,a series of hindered urea bond(HUB)containing polyurethane-urea methacrylate prepolymers and a none HUB containing polyurethane methacrylate prepolymer were prepared using isobornyl methacrylate as the reactive diluent via one-pot procedure.The prepolymers were characterized fully by various techniques.Then,their thermosets were fabricated via UV curing in presence of a photo initiator,and their mechanical property and thermal behavior were investigated and compared.Different from the none HUB containing thermoset,the HUB containing thermosets(defined as PUT)could be recycled and reprocessed by hot press under relatively mild conditions with high recovery ratio of mechanical property.Furthermore,zinc oxide(ZnO)nanoparticles were modified with 3-(trimethoxysilyl)propyl methacrylate and the modified ZnO(defined as ZnO-TPM)was dispersed and polymerized into PUT matrix to prepare their nanocomposites.The influence of ZnO-TPM on the mechanical performance of the composites was evaluated,which indicated that the Young’s modulus and tensile strength increased gradually to the maximum values at ZnO-TPM content of 1 wt%and then decreased.The composites also displayed good reprocessability with improved recovery ratio compared to the pure PUT sample.In addition,the composite materials exhibited strong UV absorption capacity,implying their potential application in the circumstance where UV-shielding was required.
基金supported by the National Key Research and Development Program of China(Grant No.2022YFA1402203)the Shanghai Municipal Science and Technology Major Project(Grant No.2019SHZDZX01)+5 种基金supported by the National Key R&D Program of China(Grants No.2023YFA1406100)the Double First-Class Initiative Fund of ShanghaiTech Universitysupported by the National Natural Science Foundation of China(Grant No.52272265)supported by the National Science Basic Research Plan in the Shaanxi Province of China(Grant No.2024JC-YBQN-0390)supported by the open project from State Key Laboratory of Surface Physics and Department of Physics,Fudan University(Grant No.KF2022-13)supported by the National Natural Science Foundation of China(Grant No.52302010)。
文摘Exploration of exotic phenomena in magnetic topological systems is at the frontier of condensed matter physics,holding a significant promise for applications in topological spintronics.However,complex magnetic structures carrying nontrivial topological properties hinder its progresses.Here,we investigate the pressure effect on the novel topological kagome magnets GdV_(6)Sn_(6) and TbV_(6)Sn_(6) to dig out the interplay between magnetic Gd/Tb layers and nonmagnetic V-based kagome sublattice.The pressure-tuned magnetic transition temperature Tm in both the compounds exhibit a turning point at the critical pressure P_(c),accompanied with a sign reversal in anomalous Hall effect(AHE).The separation of intrinsic and extrinsic contributions using the Tian-Ye-Jin scaling model suggests that the intrinsic mechanism originating from the electronic Berry curvature holds the priority in the competition with extrinsic mechanism in AHE.The above-mentioned findings can be attributed to the combined effect of pressure-tuned band topology and magnetic interaction in segregated layers.Our results provide a practical route to design and manipulate the intrinsic AHE in magnetic topological materials.
基金supported in part by the National Key R&D Program of China (Grant Nos.2023YFF1203600 and 2023YFF0718400)the National Natural Science Foundation of China (Grant Nos.62122036,12322407,62034004,61921005,and 12074176)+2 种基金the Leading-edge Technology Program of Jiangsu Natural Science Foundation (Grant No.BK20232004)the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No.XDB44000000)support from the AIQ Foundation and the eScience Center of Collaborative Innovation Center of Advanced Microstructures。
文摘Detecting tiny deformations or vibrations, particularly those associated with strains below 1%, is essential in various technological applications. Traditional intrinsic materials, including metals and semiconductors, face challenges in simultaneously achieving initial metallic state and strain-induced insulating state, hindering the development of highly sensitive mechanical sensors. Here we report an ultrasensitive mechanical sensor based on a strain-induced tunable ordered array of metallic and insulating states in the single-crystal bronze-phase vanadium dioxide [VO_(2)(B)] quantum material. It is shown that the initial metallic state in the VO_(2)(B) flake can be tuned to the insulating state by applying a weak uniaxial tensile strain. Such a unique property gives rise to a record-high gauge factor of above 607970, surpassing previous values by an order of magnitude, with excellent linearity and mechanical resilience as well as durability. As a proof-of-concept application, we use our proposed mechanical sensor to demonstrate precise sensing of the micro piece, gentle airflows and water droplets. We attribute the superior performance of the sensor to the strain-induced continuous metal-insulator transition in the single-crystal VO_(2)(B) flake, evidenced by experimental and simulation results. Our findings highlight the potential of exploiting correlated quantum materials for next-generation ultrasensitive flexible mechanical sensors, addressing critical limitations in traditional materials.
文摘Background:Potassium(K)deficiency has become a common field production problem following the widespread adoption of Bacillus thuringiensis(Bt)transgenic cotton(Gossypium hirsutum L.)worldwide.The purpose of this study was to clarify whether the introduction of Bt gene directly reduces the K-use efficiency of cotton to induce K deficiency.Results:The cotton variety,Jihe 321(wild type,WT)and its two Bt(Cry1Ac)-transgenic overexpression lines(OE-29317,OE 29312)were studied in field with low soil-test K~+(47.8 mg·kg~(-1)).In the field with low soil-test K~+,only OE 29317 had less biomass and K~+accumulation than the WT at some growth stages.Both Bt lines produced similar or even greater seed cotton yield than WT in the field.When the Bt gene(~70%)in OE-29317 and OE-29312 plants was silenced by virus-induced gene silencing(VIGS),the VIGS Bt plants did not produce more biomass than VIGSgreen fluorescent protein(control)plants.Conclusions:The introduction of Bt gene did not necessarily hinder the K use efficiency of the cotton lines under this study.Keywords:Biomass,Bt(Bacillus thuringiensis)gene,Cotton(Gossypium hirsutum L.),K uptake,K utilization index,Yield。
文摘Environmental Footprints:Analyzing and Mitigating the Environmental Burden from Anthropogenic Activities Introduction With the progress of industrialization and urbanization,anthropogenic activities have led to considerable pres-sure on the Earth,hindering global sustainable development.
文摘Chinese college students reading in a foreign language seem to read with less understanding and at a considerably slower speed. The factors that hinder Chinese college students' English reading were analyzed at the lexical level, the syntactic level,and the discourse level. And then, several reading strategies were recommended to overcome such reading difficulties.
基金financially supported by the National Natural Science Foundation of China (Nos. 22105018, 22002003 and 22179009)。
文摘Simultaneous electrochemical synthesis of high-valueadded chemicals and hydrogen is a promising technology for efficient carbon utilization and renewable energy storage. However, the lack of rational guidance for designing efficient catalysts for electrosynthesis significantly hinders its development.
基金supported by the National Natural Science Foundation of China(31672192)the Agricultural Science and Technology Innovation Fund Project of Jiangsu Province(CX(18)2020)+1 种基金the National Key Research and Development Project(2018YFD1000402)the Foundation of Key Laboratory of Landscaping(KF201801).
文摘Chrysanthemum is frequently attacked by aphids,which greatly hinders the growth and ornamental value of this plant species.WRKY transcription factors play an important role in the response to biotic stresses such as pathogen and insect stresses.Here,chrysanthemum CmWRKY53 was cloned,and its expression was induced by aphid infestation.To verify the role of CmWRKY53 in resistance to aphids,CmWRKY53 transgenic chrysanthemum was generated.CmWRKY53 was found to mediate the susceptibility of chrysanthemum to aphids.The expression levels of secondary metabolite biosynthesis genes,such as peroxidase-and polyphenol oxidase-encoding genes,decreased in CmWRKY53-overexpressing(CmWRKY53-Oe)plants but dramatically increased in chimeric dominant repressor(CmWRKY53-SRDX)plants,suggesting that CmWRKY53 contributes to the susceptibility of chrysanthemum to aphids,possibly due to its role in the regulation of secondary metabolites.
基金The work cited in this review was supported by the National Natural Science Foundation of China (No, 928700801 and No 2880201)
文摘Over 2 x 10(8) tons of polymers are produced every year, and a large portion of polymers faces the degradation problem. There are many effective methods to protect polymers against degradation and the addition of stabilizers to polymer remains the most convenient and effective way of enhancing polymer life and performance. In this article, a series of effective stabilizers with optimal molecular weight (MW), including common, monomeric and polymeric stabilizers (antioxidant and light stabilizer) were synthesized using isocyanation, controlled isocyanation, hydrosilylation, epoxide addition, macroreaction of stabilizing functional compounds and polymerization of monomeric stabilizers. The structure and performance of these new stabilizers were characterized by using IR, NMR, MS, UV-spectra, XPS and elemental analysis. The current development of stabilizer synthesis was also reviewed.
文摘Copolymerization of propylene and hindered piperidine monomers was carried out over a high activity supported Ziegler-Natta catalyst, using Al(C2H5)(3) as cocatalyst. Factors which affect the copolymerization were studied, The copolymers exhibited high light stability without adding extra light stabilizers. A self-stabilized polypropylene was prepared.
基金supported by the China Agriculture Research System(CARS-46)Fundamental Research Funds for the Central Universities(XDJK2017B008,XDJK2017C035,XDJK2019C025,5360300098)+1 种基金Natural Science Foundation of Chongqing(cstc2020jcyj-msxmX0438)National Natural Science Foundation of China(32071651)。
文摘The Chinese longsnout catfish(Leiocassis longirostris Günther)is one of the most economically important freshwater fish in China.As wild populations have declined sharply in recent years,it is also a valuable model for research on sexual dimorphism,comparative biology,and conservation.However,the current lack of high-quality chromosome-level genome information for the species hinders the advancement of comparative genomic analysis and evolutionary studies.Therefore,we constructed the first high-quality chromosomelevel reference genome for L.longirostris.The total genome was 703.19 Mb,with 389 contigs and contig N50 length of 4.29 Mb.Using high-throughput chromosome conformation capture(Hi-C)data,the genome sequences(685.53 Mb)were scaffolded into 26 chromosomes ranging from 17.36 to 43.97 Mb,resulting in a chromosomal anchoring rate for the genome of 97.44%.In total,23708 protein-coding genes were identified in the genome.Phylogenetic analysis indicated that L.longirostris and its closest related species P.fulvidraco diverged approximately 26.6 million years ago.This highquality reference genome of L.longirostris should pave the way for future genomic comparisons and evolutionary research.
基金the National Natural Science Foundation of China(Nos.51973113,51133003,and 21774078).
文摘In this contribution,we reported the preparation of vitrimers by using commodity thermoplastics via post crosslinking with hindered urea bonds(HUBs).First,three hindered urea diisocyanates(HUDIs)were synthesized via the reactions of N,N'-di-tert-butylethylenediamine,N,N'-diethylethylenediamine,and piperazine with isophorone diisocyanate(IPDI).Thereafter,these HUDIs were used as the crosslinking agents to crosslink poly(hydroxyether of bisphenol A)(PH),a commodity thermoplastics.Fourier transform infrared(FTIR)spectroscopy and dynamic mechanical thermal analyses(DMTA)indicated that the PH thermosets were successfully obtained.It was found that the thermosets displayed the behavior of vitrimers.The PH thermosets can be reprocessed at elevated temperature without using catalyst and the mechanical strengths of vitrimers were recovered as high as 95%.The reprocessing properties are attributable to dynamic exchange reaction of hindered urea bonds,contingent on types of hindered urea bonds.
基金Sasakawa Scientific Research Grant from the Japan Science Society.
文摘Norbornene derivatives exo,endo-2-[2-(3,5-di-tert-butyl-4-hydroxyphenoxy)-acetoxy]methyl-5-norbornene(M1) and 3,3,5,5-tetramethyl-4-piperidinyl 5-norbornene-exo,endo-2-carboxylate(M2)were synthesized and polymerized by RuCl_2(=CHPh)(PCy_3)_2 to prepare a novel kind of bi-functional polymer bearing sterically hindered phenol(SHP)and hindered amine(HLAS)groups via ring-opening metathesis polymerization(ROMP).The resulting copolymers were characterized by gel permeation chromatography(GPC),~1H-NMR and differen...
基金the National Key R&D Program of China(2017YFA0207600)National Outstanding Youth Science Fund Project of National Natural Science Foundation of China(61925401)+2 种基金PKU-Baidu Fund Project(2019BD002)National Natural Science Foundation of China(92064004,61927901,61421005,61674006)the 111 Project(B18001).
文摘In recent years,deep learning has made tremendous achievements in computer vision,natural language processing,man-machine games and so on,where artificial intelligence can reach or go beyond the level of human beings.However,behind so many glories,some serious challenges exist in the bottom hardware,hindering the further development of Artificial Intelligence.
基金Funded by the National Natural Science Foundation of China(No.51472191)the Wuhan City Chenguang Project(No.2014070404010208)+2 种基金the Natural Science Foundation of Hubei Province(Nos.2014CFB343 and 2014CFB859)the Doctoral Program of Higher Education(No.20130143110013)the Key Technology Innovation Project of Hubei Province(No.2013AAA017)
文摘The corrosion of ECR glass fiber was investigated by the analysis methods of weight loss ratio under different acids and at various durations.Weight loss,leaching of cations,and surface composition of ECR glass fiber were analyzed.The corrosion mechanism of ECR glass fiber in acid environment was also discussed.The experimental results showed that the corrosion degree of ECR glass fiber in different acids obeyed the order： HNO3〉H2SO4〉HCl.The acid effects on corrosion of ECR glass fiberis were totally different.Hydrochloric acid mainly destroyed the network structure of [AlO4],while sulfuric acid and nitric acid mainly destroyed the structure of [SiO4].The acid resistance of ECR glass fiber is much better than that of E glass fiber due to the generation of intermediate product silicic acid gel Si（OH）4 during ion exchange.It can adhere to the glass surface to form a thin film and hinder the proceeding of corrosion.
基金supported by the Project of Major Science and Technology in Anhui Province(202003a06020021)the Project of Innovation and Training of Anhui Agricultural University(XJDC2021084)the National Natural Science Foundation of China(U20A2045).
文摘Self-incompatibility(SI)is a kind of plant fertilization obstacle,which can prevent the harmful effects of inbreeding decline,but it hinders the breeding of inbred lines.Tea plants have SI and long-term cross-pollination,which limits the progress of genetic research and variety improvement.However,the mechanism of SI in tea plants is still a mystery.Herein,microscopic observation showed that the pollen tube could pass through the base of style and enter the ovary cavity after 48 h of self-pollination at different flowering stages,and the SI intensity at bud stage and full bloom stage was lower than initial bloom stage.RNA-seq analysis showed that 1,463 and 1,409 differentially expressed genes(DEGs)were associated with low SI at bud stage and full bloom stage,respectively,and 507 DEGs were associated with SI at initial bloom stage.The results of qRT-PCR validation of 20 DEGs were consistent with the RNA-seq data.Furthermore,CsRNS,CsSRKL5 and CsSRKL8 specifically expressed in style,which may be related to the low SI at bud stage,and three CsACC genes may be related to the low SI at full bloom stage.The results provide useful information for understanding the mechanism of SI in tea plants.
