Protein-mediated chromatin interactions can be revealed by coupling proximity-based ligation with chromatin immunoprecipitation.However,these techniques require complex experimental procedures and millions of cells pe...Protein-mediated chromatin interactions can be revealed by coupling proximity-based ligation with chromatin immunoprecipitation.However,these techniques require complex experimental procedures and millions of cells per experiment,which limits their widespread application in life science research.Here,we develop a novel method,Hi-Tag,that identifies high-resolution,long-range chromatin interactions through transposase tagmentation and chromatin proximity ligation(with a phosphorothioate-modified linker).Hi-Tag can be implemented using as few as 100,000 cells,involving simple experimental procedures that can be completed within 1.5 days.Meanwhile,Hi-Tag is capable of using its own data to identify the binding sites of specific proteins,based on which,it can acquire accurate interaction information.Our results suggest that Hi-Tag has great potential for advancing chromatin interaction studies,particularly in the context of limited cell availability.展开更多
Strain engineering can serve as a powerful technique for modulating the exotic properties arising from the atomic structure of materials.Examples have been demonstrated that one-dimensional(1D)structure can serve as a...Strain engineering can serve as a powerful technique for modulating the exotic properties arising from the atomic structure of materials.Examples have been demonstrated that one-dimensional(1D)structure can serve as a great platform for modulating electronic band structure and phonon dispersion via strain control.Particularly,in a van der Waals material silicon diphosphide(SiP_(2)),quasi-1D zigzag phosphorus–phosphorus(P–P)chains are embedded inside the crystal structure,and can show unique phonon vibration modes and realize quasi-1D excitons.Manipulating those optical properties by the atom displacements via strain engineering is of great interest in understanding underlying mechanism of such P–P chains,however,which remains elusive.Herein,we demonstrate the strain engineering of Raman and photoluminescence(PL)spectra in quasi-1D P–P chains and resulting in anisotropic manipulation in SiP_(2).We find that the phonon frequencies of SiP_(2)in Raman spectra linearly evolve with a uniaxial strain along/perpendicular to the quasi-1D P–P chain directions.Interestingly,by applying tensile strain along the P–P chains,the band gap energy of strained SiP_(2)can significantly decrease with a tunable value of~55 meV.Based on arsenic(As)element doping into SiP_(2),the strain-induced redshifts of phonon frequencies decrease,indicating the stiffening of the phonon vibration with the increased arsenic doping level.Such results provide an opportunity for strain engineering of the light–matter interactions in the quasi-1D P–P chains of SiP_(2)crystal for potential optical applications.展开更多
Light-matter interactions in low-dimensional quantum-confined structures can dominate the optical properties of the materials and lead to optoelectronic applications.In anisotropic layered silicon diphosphide(SiP2)cry...Light-matter interactions in low-dimensional quantum-confined structures can dominate the optical properties of the materials and lead to optoelectronic applications.In anisotropic layered silicon diphosphide(SiP2)crystal,the embedded quasi-onedimensional(1D)phosphorus–phosphorus(P–P)chains directly result in an unconventional quasi-1D excitonic state,and a special phonon mode vibrating along the P–P chains,establishing a unique 1D quantum-confined system.Alloying SiP2 with the homologous element serves as an effective way to study the properties of these excitons and phonons associated with the quasi-1D P–P chains,as well as the strong interaction between these quasiparticles.However,the experimental observation and the related optical spectral understanding of SiP2 with isoelectronic dopants remain elusive.Herein,with the photoluminescence and Raman spectroscopy measurements,we demonstrate the redshift of the confined excitonic peak and the stiffening of the phonon vibration mode■of a series of Si(P1−xAsx)2 alloys with increasing arsenic(As)compositions.This anomalous stiffening of■is attributed to the selective substitution of As atoms for P atoms within the P–P chains,which is confirmed via our scanning transmission electron microscopy investigation.Such optical spectra evolutions with selective substitution pave a new way to understand the 1D quantum confinement in semiconductors,offering opportunities to explore quasi-1D characteristics in SiP2 and the resulting photonic device application.展开更多
基金supported by the National Natural Science Foundation of China(32221005)the Earmarked Fund for CARS(CARS-35)+1 种基金the National Natural Science Foundation of China Outstanding Youth(32125035)Major Project of Hubei Hongshan Laboratory(2021hszd003)。
文摘Protein-mediated chromatin interactions can be revealed by coupling proximity-based ligation with chromatin immunoprecipitation.However,these techniques require complex experimental procedures and millions of cells per experiment,which limits their widespread application in life science research.Here,we develop a novel method,Hi-Tag,that identifies high-resolution,long-range chromatin interactions through transposase tagmentation and chromatin proximity ligation(with a phosphorothioate-modified linker).Hi-Tag can be implemented using as few as 100,000 cells,involving simple experimental procedures that can be completed within 1.5 days.Meanwhile,Hi-Tag is capable of using its own data to identify the binding sites of specific proteins,based on which,it can acquire accurate interaction information.Our results suggest that Hi-Tag has great potential for advancing chromatin interaction studies,particularly in the context of limited cell availability.
基金the National Natural Science Foundation of China(Nos.51861145201,52072168,21733001,and 91750101)the National Key Basic Research Program of the Ministry of Science and Technology of China(Nos.2018YFA0306200 and 2021YFA1202901)Jiangsu Key Laboratory of Artificial Functional Materials.L.Y.F.acknowledges financial support from the start-up fund of Chongqing University(No.02110011044171).
文摘Strain engineering can serve as a powerful technique for modulating the exotic properties arising from the atomic structure of materials.Examples have been demonstrated that one-dimensional(1D)structure can serve as a great platform for modulating electronic band structure and phonon dispersion via strain control.Particularly,in a van der Waals material silicon diphosphide(SiP_(2)),quasi-1D zigzag phosphorus–phosphorus(P–P)chains are embedded inside the crystal structure,and can show unique phonon vibration modes and realize quasi-1D excitons.Manipulating those optical properties by the atom displacements via strain engineering is of great interest in understanding underlying mechanism of such P–P chains,however,which remains elusive.Herein,we demonstrate the strain engineering of Raman and photoluminescence(PL)spectra in quasi-1D P–P chains and resulting in anisotropic manipulation in SiP_(2).We find that the phonon frequencies of SiP_(2)in Raman spectra linearly evolve with a uniaxial strain along/perpendicular to the quasi-1D P–P chain directions.Interestingly,by applying tensile strain along the P–P chains,the band gap energy of strained SiP_(2)can significantly decrease with a tunable value of~55 meV.Based on arsenic(As)element doping into SiP_(2),the strain-induced redshifts of phonon frequencies decrease,indicating the stiffening of the phonon vibration with the increased arsenic doping level.Such results provide an opportunity for strain engineering of the light–matter interactions in the quasi-1D P–P chains of SiP_(2)crystal for potential optical applications.
基金This research was supported by the National Natural Science Foundation of China(Nos.52072168,51861145201,21733001 and 91750101)the National Key R&D Program of China(Nos.2018YFA0306200 and 2021YFA1202901)Y.F.L.acknowledges financial support by the start-up fund from Chongqing University(No.02110011044171).
文摘Light-matter interactions in low-dimensional quantum-confined structures can dominate the optical properties of the materials and lead to optoelectronic applications.In anisotropic layered silicon diphosphide(SiP2)crystal,the embedded quasi-onedimensional(1D)phosphorus–phosphorus(P–P)chains directly result in an unconventional quasi-1D excitonic state,and a special phonon mode vibrating along the P–P chains,establishing a unique 1D quantum-confined system.Alloying SiP2 with the homologous element serves as an effective way to study the properties of these excitons and phonons associated with the quasi-1D P–P chains,as well as the strong interaction between these quasiparticles.However,the experimental observation and the related optical spectral understanding of SiP2 with isoelectronic dopants remain elusive.Herein,with the photoluminescence and Raman spectroscopy measurements,we demonstrate the redshift of the confined excitonic peak and the stiffening of the phonon vibration mode■of a series of Si(P1−xAsx)2 alloys with increasing arsenic(As)compositions.This anomalous stiffening of■is attributed to the selective substitution of As atoms for P atoms within the P–P chains,which is confirmed via our scanning transmission electron microscopy investigation.Such optical spectra evolutions with selective substitution pave a new way to understand the 1D quantum confinement in semiconductors,offering opportunities to explore quasi-1D characteristics in SiP2 and the resulting photonic device application.
