Traditional transgenic detection methods require high test conditions and struggle to be both sensitive and efficient.In this study,a one-tube dual recombinase polymerase amplification(RPA)reaction system for CP4-EPSP...Traditional transgenic detection methods require high test conditions and struggle to be both sensitive and efficient.In this study,a one-tube dual recombinase polymerase amplification(RPA)reaction system for CP4-EPSPS and Cry1Ab/Ac was proposed and combined with a lateral flow immunochromatographic assay,named“Dual-RPA-LFD”,to visualize the dual detection of genetically modified(GM)crops.In which,the herbicide tolerance gene CP4-EPSPS and the insect resistance gene Cry1Ab/Ac were selected as targets taking into account the current status of the most widespread application of insect resistance and herbicide tolerance traits and their stacked traits.Gradient diluted plasmids,transgenic standards,and actual samples were used as templates to conduct sensitivity,specificity,and practicality assays,respectively.The constructed method achieved the visual detection of plasmid at levels as low as 100 copies,demonstrating its high sensitivity.In addition,good applicability to transgenic samples was observed,with no cross-interference between two test lines and no influence from other genes.In conclusion,this strategy achieved the expected purpose of simultaneous detection of the two popular targets in GM crops within 20 min at 37°C in a rapid,equipmentfree field manner,providing a new alternative for rapid screening for transgenic assays in the field.展开更多
Due to their excellent carrier mobility,high absorption coefficient and narrow bandgap,most 2D IVA metal chalcogenide semiconductors(GIVMCs,metal=Ge,Sn,Pb;chalcogen=S,Se)are regarded as promising candidates for realiz...Due to their excellent carrier mobility,high absorption coefficient and narrow bandgap,most 2D IVA metal chalcogenide semiconductors(GIVMCs,metal=Ge,Sn,Pb;chalcogen=S,Se)are regarded as promising candidates for realizing high-performance photodetectors.We synthesized high-quality two-dimensional(2D)tin sulfide(SnS)nanosheets using the physical vapor deposition(PVD)method and fabricated a 2D SnS visible-light photodetector.The photodetector exhibits a high photoresponsivity of 161 A·W-1 and possesses an external quantum efficiency of 4.45×10^(4)%,as well as a detectivity of 1.15×10^(9) Jones under 450 nm blue light illumination.Moreover,under poor illumination at optical densities down to 2 mW·cm^(-2),the responsivity of the device is higher than that at stronger optical densities.We suggest that a photogating effect in the 2D SnS photodetector is mainly responsible for its low-light responsivity.Defects and impurities in 2D SnS can trap carriers and form localized electric fields,which can delay the recombination process of electron-hole pairs,prolong carrier lifetimes,and thus improve the low-light responsivity.This work provides design strategies for detecting low levels of light using photodetectors made of 2D materials.展开更多
Correction to:npj Computational Materials https://doi.org/10.1038/s41524-018-0095-6,published online 24 July 2018 In this article the affiliation details for author Yinghao Chu were incorrectly given as‘Department of...Correction to:npj Computational Materials https://doi.org/10.1038/s41524-018-0095-6,published online 24 July 2018 In this article the affiliation details for author Yinghao Chu were incorrectly given as‘Department of Materials Science and Engineering,National Chiao Tung University,30010 Hsinchu,Taiwan’but should have been‘Department of Materials Science and Engineering,National Chiao Tung University,30010 Hsinchu,Taiwan,China’.The original article has been corrected.展开更多
Domain orientations and their volume ratios in ferroelectrics are recognized as a compelling topic recently for domain switching dynamics and domain stability in devices application.Here,an optimized second harmonic g...Domain orientations and their volume ratios in ferroelectrics are recognized as a compelling topic recently for domain switching dynamics and domain stability in devices application.Here,an optimized second harmonic generation method has been explored for ferroelectric domain characterization.Combing a unique theoretical model with azimuth-polarization-dependent second harmonic generation response,the complex domain components and their distributions can be rigidly determined in ferroelectric thin films.Using the proposed model,the domain structures of rhombohedral BiFeO_(3) films with 71°and 109°domain wall,and,tetragonal BiFeO_(3),Pb(Zr_(0.2)Ti_(0.8))O_(3),and BaTiO_(3) ferroelectric thin films are analyzed and the corresponding polarization variants are determined.This work could provide a powerful and all-optical method to track and evaluate the evolution of ferroelectric domains in the ferroelectric-based devices.展开更多
Coating crack and interfacial delamination are recognized as two critical factors inducing spallation of thick diamond-like carbon(DLC)coatings.The effect of the two factors is found to dramatically accelerate the fai...Coating crack and interfacial delamination are recognized as two critical factors inducing spallation of thick diamond-like carbon(DLC)coatings.The effect of the two factors is found to dramatically accelerate the failure of thick DLC coatings.However,there are few reports on the effect of interfacial delamination on coating crack.In this work,in order to investigate the evolution of the coating crack and interfacial delamination,as well as the effect of interfacial delamination on coating crack,a finite element model that combines the bilinear cohesive zone model and the extended finite element method(XFEM)is established.It is found that the occurrence of interfacial delamination triggers a second expansion of coating crack.Factors influencing the degree of interfacial delamination on coating crack can be modulated by coating thickness and coating elastic modulus.As the coating thickness increases,the length of interfacial delamination increases,and thus the propagation of coating crack is accelerated.In contrast,the increase of coating elastic modulus could reduce the length of interfacial delamination,which consequently weakens its influence on the propagation of coating crack.展开更多
Topological polar vortices, which are electric analogs of magnetic objects, present great potential in applications of future nanoelectronics because of their nanometer size, anomalous dielectric response, and chirali...Topological polar vortices, which are electric analogs of magnetic objects, present great potential in applications of future nanoelectronics because of their nanometer size, anomalous dielectric response, and chirality. To enable the functionalities, it is prerequisite to manipulate the polar states and chirality by using external stimuli. Here, we probe the evolutions of polar state and chirality evolutions of topological polar vortices in Pb TiO;/Sr TiO;superlattices under an electric field by using atomically resolved in situ scanning transmission electron microscopy and phase-field simulations. We find that, under electric field, the chiral vortex cores can be moved laterally to form close-pair structures, transform into a/c domain stripes, and finally become a nonchiral c-domain. Such transition is reversible and spontaneous after bias removal. Interestingly, during switching and backswitching events, the vortex rotation can be changed, offering a potential strategy to manipulate vortex chirality. The revealed dynamic behavior of individual polar vortices at the atomic scale provides fundamentals for future device applications.展开更多
Associations between 3D chromatin architectures and epigenetic modifications have been characterized in animals.However,any impact of DNA methylation on chromatin architecture in plants is understudied,which is confin...Associations between 3D chromatin architectures and epigenetic modifications have been characterized in animals.However,any impact of DNA methylation on chromatin architecture in plants is understudied,which is confined to Arabidopsis thaliana.Because plant species differ in genome size,composition,and overall chromatin packing,it is unclear to what extent findings from A.thaliana hold in other species.Moreover,the incomplete chromatin architectural profiles and the low-resolution high-throughput chromosome conformation capture(Hi-C)data from A.thaliana have hampered characterizing its subtle chromatin structures and their associations with DNA methylation.We constructed a high-resolution Hi-C interaction map for the null OsMET1-2(the major CG methyltransferase in rice)mutant(osmet1-2)and isogenic wild-type rice(WT).Chromatin structural changes occurred in osmetl-2,including intra-/inter-chromosomal interactions,compartment transition,and topologically associated domains(TAD)variations.Our findings provide novel insights into the potential function of DNA methylation in TAD formation in rice and confirmed DNA methylation plays similar essential roles in chromatin packing in A,thaliana and rice.展开更多
基金supported by the Scientific and Innovative Action Plan of Shanghai(21N31900800)Shanghai Rising-Star Program(23QB1403500)+4 种基金the Shanghai Sailing Program(20YF1443000)Shanghai Science and Technology Commission,the Belt and Road Project(20310750500)Talent Project of SAAS(2023-2025)Runup Plan of SAAS(ZP22211)the SAAS Program for Excellent Research Team(2022(B-16))。
文摘Traditional transgenic detection methods require high test conditions and struggle to be both sensitive and efficient.In this study,a one-tube dual recombinase polymerase amplification(RPA)reaction system for CP4-EPSPS and Cry1Ab/Ac was proposed and combined with a lateral flow immunochromatographic assay,named“Dual-RPA-LFD”,to visualize the dual detection of genetically modified(GM)crops.In which,the herbicide tolerance gene CP4-EPSPS and the insect resistance gene Cry1Ab/Ac were selected as targets taking into account the current status of the most widespread application of insect resistance and herbicide tolerance traits and their stacked traits.Gradient diluted plasmids,transgenic standards,and actual samples were used as templates to conduct sensitivity,specificity,and practicality assays,respectively.The constructed method achieved the visual detection of plasmid at levels as low as 100 copies,demonstrating its high sensitivity.In addition,good applicability to transgenic samples was observed,with no cross-interference between two test lines and no influence from other genes.In conclusion,this strategy achieved the expected purpose of simultaneous detection of the two popular targets in GM crops within 20 min at 37°C in a rapid,equipmentfree field manner,providing a new alternative for rapid screening for transgenic assays in the field.
基金the National Natural Science Foundation of China(Grant Nos.1872251 and 11875229).
文摘Due to their excellent carrier mobility,high absorption coefficient and narrow bandgap,most 2D IVA metal chalcogenide semiconductors(GIVMCs,metal=Ge,Sn,Pb;chalcogen=S,Se)are regarded as promising candidates for realizing high-performance photodetectors.We synthesized high-quality two-dimensional(2D)tin sulfide(SnS)nanosheets using the physical vapor deposition(PVD)method and fabricated a 2D SnS visible-light photodetector.The photodetector exhibits a high photoresponsivity of 161 A·W-1 and possesses an external quantum efficiency of 4.45×10^(4)%,as well as a detectivity of 1.15×10^(9) Jones under 450 nm blue light illumination.Moreover,under poor illumination at optical densities down to 2 mW·cm^(-2),the responsivity of the device is higher than that at stronger optical densities.We suggest that a photogating effect in the 2D SnS photodetector is mainly responsible for its low-light responsivity.Defects and impurities in 2D SnS can trap carriers and form localized electric fields,which can delay the recombination process of electron-hole pairs,prolong carrier lifetimes,and thus improve the low-light responsivity.This work provides design strategies for detecting low levels of light using photodetectors made of 2D materials.
文摘Correction to:npj Computational Materials https://doi.org/10.1038/s41524-018-0095-6,published online 24 July 2018 In this article the affiliation details for author Yinghao Chu were incorrectly given as‘Department of Materials Science and Engineering,National Chiao Tung University,30010 Hsinchu,Taiwan’but should have been‘Department of Materials Science and Engineering,National Chiao Tung University,30010 Hsinchu,Taiwan,China’.The original article has been corrected.
基金This work was financially supported by the National Natural Science Foundation of China(51572233,61574121,11372266 and 11474359)the National Key Research and Development Program of China(2016YFB0501303).
文摘Domain orientations and their volume ratios in ferroelectrics are recognized as a compelling topic recently for domain switching dynamics and domain stability in devices application.Here,an optimized second harmonic generation method has been explored for ferroelectric domain characterization.Combing a unique theoretical model with azimuth-polarization-dependent second harmonic generation response,the complex domain components and their distributions can be rigidly determined in ferroelectric thin films.Using the proposed model,the domain structures of rhombohedral BiFeO_(3) films with 71°and 109°domain wall,and,tetragonal BiFeO_(3),Pb(Zr_(0.2)Ti_(0.8))O_(3),and BaTiO_(3) ferroelectric thin films are analyzed and the corresponding polarization variants are determined.This work could provide a powerful and all-optical method to track and evaluate the evolution of ferroelectric domains in the ferroelectric-based devices.
基金the National Natural Science Foundation of China(Grants 11875229,51872251,11502224,and 51701172)the National Key Research and Development Program of China(Grant 2016YFB0501303)the Educational Commission of Hunan Province of China(Grant 16C1527).
文摘Coating crack and interfacial delamination are recognized as two critical factors inducing spallation of thick diamond-like carbon(DLC)coatings.The effect of the two factors is found to dramatically accelerate the failure of thick DLC coatings.However,there are few reports on the effect of interfacial delamination on coating crack.In this work,in order to investigate the evolution of the coating crack and interfacial delamination,as well as the effect of interfacial delamination on coating crack,a finite element model that combines the bilinear cohesive zone model and the extended finite element method(XFEM)is established.It is found that the occurrence of interfacial delamination triggers a second expansion of coating crack.Factors influencing the degree of interfacial delamination on coating crack can be modulated by coating thickness and coating elastic modulus.As the coating thickness increases,the length of interfacial delamination increases,and thus the propagation of coating crack is accelerated.In contrast,the increase of coating elastic modulus could reduce the length of interfacial delamination,which consequently weakens its influence on the propagation of coating crack.
基金supported by the National Natural Science Foundation of China(Grant Nos.51991340,51991344,11974023,51672007,21773303,11875229,and 51872251)the Chinese Academy of Sciences(Grant Nos.XDB33030200,and ZDYZ2015-1)+4 种基金the National Key R&D Program of China(Grant No.2016YFA0300804)the Key R&D Program of Guangdong Province(Grant Nos.2018B030327001,2018B010109009,and2019B010931001)the Bureau of Industry and Information Technology of Shenzhen(Grant No.201901161512)the Beijing Excellent Talents Training Support(Grant No.2017000026833ZK11)the“2011 Program”Peking-Tsinghua-IOP Collaborative Innovation Center for Quantum Matter。
文摘Topological polar vortices, which are electric analogs of magnetic objects, present great potential in applications of future nanoelectronics because of their nanometer size, anomalous dielectric response, and chirality. To enable the functionalities, it is prerequisite to manipulate the polar states and chirality by using external stimuli. Here, we probe the evolutions of polar state and chirality evolutions of topological polar vortices in Pb TiO;/Sr TiO;superlattices under an electric field by using atomically resolved in situ scanning transmission electron microscopy and phase-field simulations. We find that, under electric field, the chiral vortex cores can be moved laterally to form close-pair structures, transform into a/c domain stripes, and finally become a nonchiral c-domain. Such transition is reversible and spontaneous after bias removal. Interestingly, during switching and backswitching events, the vortex rotation can be changed, offering a potential strategy to manipulate vortex chirality. The revealed dynamic behavior of individual polar vortices at the atomic scale provides fundamentals for future device applications.
基金the National Natural Science Foundation of China(Grant No.31670220)the Program of Changbai Mountain Scholar。
文摘Associations between 3D chromatin architectures and epigenetic modifications have been characterized in animals.However,any impact of DNA methylation on chromatin architecture in plants is understudied,which is confined to Arabidopsis thaliana.Because plant species differ in genome size,composition,and overall chromatin packing,it is unclear to what extent findings from A.thaliana hold in other species.Moreover,the incomplete chromatin architectural profiles and the low-resolution high-throughput chromosome conformation capture(Hi-C)data from A.thaliana have hampered characterizing its subtle chromatin structures and their associations with DNA methylation.We constructed a high-resolution Hi-C interaction map for the null OsMET1-2(the major CG methyltransferase in rice)mutant(osmet1-2)and isogenic wild-type rice(WT).Chromatin structural changes occurred in osmetl-2,including intra-/inter-chromosomal interactions,compartment transition,and topologically associated domains(TAD)variations.Our findings provide novel insights into the potential function of DNA methylation in TAD formation in rice and confirmed DNA methylation plays similar essential roles in chromatin packing in A,thaliana and rice.
