The effective utilization of solar energy for hydrogen production requires an abundant supply of thermodynamically active photo-electrons;however,the photocatalysts are generally impeded by insufficient light absorpti...The effective utilization of solar energy for hydrogen production requires an abundant supply of thermodynamically active photo-electrons;however,the photocatalysts are generally impeded by insufficient light absorption and fast photocarrier recombination.Here,we report a multiple-regulated strategy to capture photons and boost photocarrier dynamics by devel-oping a broadband photocatalyst composed of defect engineered g-C_(3)N_(4)(DCN)and upconversion NaYF4:Yb^(3+),Tm^(3+)(NYF)nanocrystals.Through a precise defect engineering,the S dopants and C vacancies jointly render DCN with defect states to effectively extend the visible light absorption to 590 nm and boost photocarrier separation via a moderate electron-trapping ability,thus facilitating the subsequent re-absorption and utilization of upconverted photons/electrons.Importantly,we found a promoted interfacial charge polarization between DCN and NYF has also been achieved mainly due to Y-N interaction,which further favors the upconverted excited energy transfer from NYF onto DCN as verified both theoretically and experimentally.With a 3D architecture,the NYF@DCN catalyst exhibits a superior solar H2 evolution rate among the reported upconversion-based system,which is 19.3 and 1.5 fold higher than bulk material and DCN,respectively.This work provides an innovative strategy to boost solar utilization by using defect engineering and building up interaction between hetero-materials.展开更多
Biomedical investigations in nanotherapeutics and nanomedicine have recently intensified in pursuit of new therapies with improved efficacy.Quantum dots(QDs)are promising nanomaterials that possess a wide array of adv...Biomedical investigations in nanotherapeutics and nanomedicine have recently intensified in pursuit of new therapies with improved efficacy.Quantum dots(QDs)are promising nanomaterials that possess a wide array of advantageous properties,including electronic properties,optical properties,and engineered biocompatibility under physiological conditions.Due to these characteristics,QDs are mainly used for biomedical labeling and theranostic(therapeutic-diagnostic)agents.QDs can be functionalized with ligands to facilitate their interaction with the immune system,specific IgE,and effector cell receptors.However,undesirable side effects such as hypersensitivity and toxicity may occur,requiring further assessment.This review systematically summarizes the potential uses of QDs in the allergy field.An overview of the definition and development of QDs is provided,along with the applications of QDs in allergy studies,including the detection of allergen-specific IgE(sIgE),food allergens,and sIgE in cellular tests.The potential treatment of allergies with QDs is also described,highlighting the toxicity and biocompatibility of these nanodevices.Finally,we discuss the current findings on the immunotoxicity of QDs.Several favorable points regarding the use of QDs for allergy diagnosis and treatment are noted.展开更多
Nanoparticles have become new tools for cell biology imaging1,sub-cellular sensing2,super-resolution imaging3,4 and drug delivery5.Long-term 3D tracking of nanoparticles and their intracellular motions have advanced t...Nanoparticles have become new tools for cell biology imaging1,sub-cellular sensing2,super-resolution imaging3,4 and drug delivery5.Long-term 3D tracking of nanoparticles and their intracellular motions have advanced the understanding of endocytosis and exocytosis as well as of active transport processes6–8.The sophisticated operation of correlative optical-electron microscopy9,10 and scientific-grade cameras is often used to study intercellular processes.Nonetheless,most of these studies are still limited by the insufficient sensitivity for separating a single nanoparticle from a cluster of nanoparticles or their aggregates8,11,12.Here we report that our eyes can track a single fluorescent nanoparticle that emits over 4000 photons per 100 milliseconds under a simple microscope setup.By tracking a single nanoparticle with high temporal,spectral and spatial resolution,we show the measurement of the local viscosity of the intracellular environment.Moreover,beyond the colour domain and 3D position,we introduce excitation power density as the fifth dimension for our eyes to simultaneously discriminate multiple sets of single nanoparticles.展开更多
Phosphor-converted white-light-emitting diodes(pc-WLED)have been extensively employed as solid-state lighting sources,which have a very important role in people’s daily lives.However,due to the scarcity of the red co...Phosphor-converted white-light-emitting diodes(pc-WLED)have been extensively employed as solid-state lighting sources,which have a very important role in people’s daily lives.However,due to the scarcity of the red component,it is difficult to realize warm white light efficiently.Hence,red-emitting phosphors are urgently required for improving the illumination quality.In this work,we develop a novel orangish-red La_(4)GeO_(8):Bi^(3+) phosphor,the emission peak of which is located at 600 nm under near-ultraviolet(n-UV)light excitation.The full width at half maximum(fwhm)is 103 nm,the internal quantum efficiency(IQE)exceeds 88%,and the external quantum efficiency(EQE)is 69%.According to Rietveld refinement analysis and density functional theory(DFT)calculations,Bi^(3+) ions randomly occupy all La sites in orthorhombic La_(4)GeO_(8).Importantly,the oxygen-vacancy-induced electronic localization around the Bi3+ions is the main reason for the highly efficient orangish-red luminescence.These results provide a new perspective and insight from the local electron structure for designing inorganic phosphor materials that realize the unique luminescence performance of Bi^(3+) ions.展开更多
Although small EVs(sEVs)have been used widely as biomarkers in disease diagnosis,their heterogeneity at single EV level has rarely been revealed.This is because high-resolution characterization of sEV presents a major...Although small EVs(sEVs)have been used widely as biomarkers in disease diagnosis,their heterogeneity at single EV level has rarely been revealed.This is because high-resolution characterization of sEV presents a major challenge,as their sizes are below the optical diffraction limit.Here,we report that upconversion nanoparticles(UCNPs)can be used for super-resolution profiling the molecular heterogeneity of sEVs.We show that Er3+-doped UCNPs has better brightness and Tm3+-doped UCNPs resulting in better resolution beyond diffraction limit.Through an orthogonal experimental design,the specific targeting of UCNPs to the tumour epitope on single EV has been cross validated,resulting in the Pearson’s R-value of 0.83 for large EVs and~65%co-localization double-positive spots for sEVs.Furthermore,super-resolution nanoscopy can distinguish adjacent UCNPs on single sEV with a resolution of as high as 41.9 nm.When decreasing the size of UCNPs from 40 to 27 nm and 18 nm,we observed that the maximum UCNPs number on single sEV increased from 3 to 9 and 21,respectively.This work suggests the great potentials of UCNPs approach“digitally”quantify the surface antigens on single EVs,therefore providing a solution to monitor the EV heterogeneity changes along with the tumour progression progress.展开更多
Fluorescence polarization microscopy(FPM)aims to detect the dipole orientation of fluorophores and to resolve structural information for labeled organelles via wide-field or confocal microscopy.Conventional FPM often ...Fluorescence polarization microscopy(FPM)aims to detect the dipole orientation of fluorophores and to resolve structural information for labeled organelles via wide-field or confocal microscopy.Conventional FPM often suffers from the presence of a large number of molecules within the diffraction-limited volume,with averaged fluorescence polarization collected from a group of dipoles with different orientations.Here,we apply sparse deconvolution and least-squares estimation to fluorescence polarization modulation data and demonstrate a super-resolution dipole orientation mapping(SDOM)method that resolves the effective dipole orientation from a much smaller number of fluorescent molecules within a sub-diffraction focal area.We further apply this method to resolve structural details in both fixed and live cells.For the first time,we show that different borders of a dendritic spine neck exhibit a heterogeneous distribution of dipole orientation.Furthermore,we illustrate that the dipole is always perpendicular to the direction of actin filaments in mammalian kidney cells and radially distributed in the hourglass structure of the septin protein under specific labelling.The accuracy of the dipole orientation can be further mapped using the orientation uniform factor,which shows the superiority of SDOM compared with its wide-field counterpart as the number of molecules is decreased within the smaller focal area.Using the inherent feature of the orientation dipole,the SDOM technique,with its fast imaging speed(at sub-second scale),can be applied to a broad range of fluorescently labeled biological systems to simultaneously resolve the valuable dipole orientation information with super-resolution imaging.展开更多
The optical thermometer has shown great promise for use in the fields of aeronautical engineering,environmental monitoring and medical diagnosis.Self-referencing lanthanide thermo-probes distinguish themselves because...The optical thermometer has shown great promise for use in the fields of aeronautical engineering,environmental monitoring and medical diagnosis.Self-referencing lanthanide thermo-probes distinguish themselves because of their accuracy,calibration,photostability,and temporal dimension of signal.However,the use of conventional lanthanidedoped materials is limited by their poor reproducibility,random distance between energy transfer pairs and interference by energy migration,thereby restricting their utility.Herein,a strategy for synthesizing hetero-dinuclear complexes that comprise chemically similar lanthanides is introduced in which a pair of thermosensitive dinuclear complexes,cycTb-phEu and cycEu-phTb,were synthesized.Their structures were geometrically optimized with an internuclear distance of approximately 10.6Å.The sensitive linear temperature-dependent luminescent intensity ratios of europium and terbium emission over a wide temperature range(50–298 K and 10–200 K,respectively)and their temporal dimension responses indicate that both dinuclear complexes can act as excellent self-referencing thermometers.The energy transfer from Tb^(3+)to Eu^(3+)is thermally activated,with the most important pathway involving the ^(7)F_(1) Eu^(3+)J-multiplet at room temperature.The energy transfer from the antenna to Eu^(3+)was simulated,and it was found that the most important ligand contributions to the rate come from transfers to the Eu^(3+)upper states rather than direct ligand–metal transfer to 5D1 or 5D0.As the first molecular-based thermometer with clear validation of the metal ratio and a fixed distance between the metal pairs,these dinuclear complexes can be used as new materials for temperature sensing and can provide a new platform for understanding the energy transfer between lanthanide ions.展开更多
The orientation of fluorophores can reveal crucial information about the structure and dynamics of their associated subcellular organelles.Despite significant progress in super-resolution,fluorescence polarization mic...The orientation of fluorophores can reveal crucial information about the structure and dynamics of their associated subcellular organelles.Despite significant progress in super-resolution,fluorescence polarization microscopy remains limited to unique samples with relatively strong polarization modulation and not applicable to the weak polarization signals in samples due to the excessive background noise.Here we apply optical lock-in detection to amplify the weak polarization modulation with super-resolution.This novel technique,termed optical lock-in detection super-resolution dipole orientation mapping(OLID-SDOM),could achieve a maximum of 100 frames per second and rapid extraction of 2D orientation,and distinguish distance up to 50 nm,making it suitable for monitoring structural dynamics concerning orientation changes in vivo.OLID-SDOM was employed to explore the universal anisotropy of a large variety of GFP-tagged subcellular organelles,including mitochondria,lysosome,Golgi,endosome,etc.We found that OUF(Orientation Uniformity Factor)of OLID-SDOM can be specific for different subcellular organelles,indicating that the anisotropy was related to the function of the organelles,and OUF can potentially be an indicator to distinguish normal and abnormal cells(even cancer cells).Furthermore,dual-color super-resolution OLID-SDOM imaging of lysosomes and actins demonstrates its potential in studying dynamic molecular interactions.The subtle anisotropy changes of expanding and shrinking dendritic spines in live neurons were observed with real-time OLID-SDOM.Revealing previously unobservable fluorescence anisotropy in various samples and indicating their underlying dynamic molecular structural changes,OLID-SDOM expands the toolkit for live cell research.展开更多
Long-range and fast transport of coherent excitons is important for the development of high-speed excitonic circuits and quantum computing applications.However,most of these coherent excitons have only been observed i...Long-range and fast transport of coherent excitons is important for the development of high-speed excitonic circuits and quantum computing applications.However,most of these coherent excitons have only been observed in some low-dimensional semiconductors when coupled with cavities,as there are large inhomogeneous broadening and dephasing effects on the transport of excitons in their native states in materials.Here,by confining coherent excitons at the 2D quantum limit,we first observed molecular aggregation-enabled‘supertransport’of excitons in atomically thin two-dimensional(2D)organic semiconductors between coherent states,with a measured high effective exciton diffusion coefficient of ~346.9 cm^(2)/s at room temperature.This value is one to several orders of magnitude higher than the values reported for other organic molecular aggregates and low-dimensional inorganic materials.Without coupling to any optical cavities,the monolayer pentacene sample,a very clean 2D quantum system(~1.2 nm thick)with high crystallinity(J-type aggregation)and minimal interfacial states,showed superradiant emission from Frenkel excitons,which was experimentally confirmed by the temperature-dependent photoluminescence(PL)emission,highly enhanced radiative decay rate,significantly narrowed PL peak width and strongly directional in-plane emission.The coherence in monolayer pentacene samples was observed to be delocalised over~135 molecules,which is significantly larger than the values(a few molecules)observed for other organic thin films.In addition,the supertransport of excitons in monolayer pentacene samples showed highly anisotropic behaviour.Our results pave the way for the development of future high-speed excitonic circuits,fast OLEDs,and other optoelectronic devices.展开更多
Nowadays,viral infections are one of the greatest challenges for medical sciences and human society.While antiviral compounds and chemical inactivation remain inadequate,physical approaches based on irradiation provid...Nowadays,viral infections are one of the greatest challenges for medical sciences and human society.While antiviral compounds and chemical inactivation remain inadequate,physical approaches based on irradiation provide new potentials for prevention and treatment of viral infections,without the risk of drug resistance and other unwanted side effects.Light across the electromagnetic spectrum can inactivate the virions using ionizing and non-ionizing radiations.This review highlights the anti-viral utility of radiant methods from the aspects of ionizing radiation,including high energy ultraviolet,gamma ray,X-ray,and neutron,and non-ionizing photo-inactivation,including lasers and blue light.展开更多
Axial excitation confinement beyond the diffraction limit is crucial to the development of next-generation,super-resolution microscopy.STimulated Emission Depletion(STED)nanoscopy offers lateral super-resolution using...Axial excitation confinement beyond the diffraction limit is crucial to the development of next-generation,super-resolution microscopy.STimulated Emission Depletion(STED)nanoscopy offers lateral super-resolution using a donut-beam depletion,but its axial resolution is still over 500 nm.Total internal reflection fluorescence microscopy is widely used for single-molecule localization,but its ability to detect molecules is limited to within the evanescent field of~100 nm from the cell attachment surface.We find here that the axial thickness of the point spread function(PSF)during confocal excitation can be easily improved to 110 nm by replacing the microscopy slide with a mirror.The interference of the local electromagnetic field confined the confocal PSF to a 110-nm spot axially,which enables axial super-resolution with all laser-scanning microscopes.Axial sectioning can be obtained with wavelength modulation or by controlling the spacer between the mirror and the specimen.With no additional complexity,the mirror-assisted excitation confinement enhanced the axial resolution six-fold and the lateral resolution two-fold for STED,which together achieved 19-nm resolution to resolve the inner rim of a nuclear pore complex and to discriminate the contents of 120 nm viral filaments.The ability to increase the lateral resolution and decrease the thickness of an axial section using mirror-enhanced STED without increasing the laser power is of great importance for imaging biological specimens,which cannot tolerate high laser power.展开更多
Scientists are known as the idea explorers,technology inventors and visionaries for the great benefits of our end-users and society.They are optimistic,realistic and scientifically rigorous.The way for them to create ...Scientists are known as the idea explorers,technology inventors and visionaries for the great benefits of our end-users and society.They are optimistic,realistic and scientifically rigorous.The way for them to create new ideas and technologies can be through their intuitions and others’guidance and inspirations.Therefore scientific publishing plays an essential role in effective communications and knowledge advancements.For the past decade,rapid growth occurred in our science communities and the number of research outputs.Merely pursuing quantity of publishing may be in lack of satisfaction,given the large volume of information produced becomes overwhelming to our early career researchers,students or cross-disciplinary researchers.Top-tier journals should stay more closely connected with our most creative authors and influential research leaders,and find ways to boost more interdisciplinary discussions and inspire creative thoughts and practice.展开更多
There is an increasing interest in understanding how three-dimensional(3D)organization of the genome is regulated.Different strategies have been employed to identify genome-wide chromatin interactions.However,due to c...There is an increasing interest in understanding how three-dimensional(3D)organization of the genome is regulated.Different strategies have been employed to identify genome-wide chromatin interactions.However,due to current limitations in resolving genomic contacts,visualization and validation of these genomic loci with sub-kilobase resolution remain unsolved to date.Here,we describe Tn5 transposase-based Fluorescencein situhybridization(Tn5-FISH),a PCR-based,cost-effective imaging method,which can co-localize the genomic loci with sub-kilobase resolution,dissect genome architecture,and verify chromatin interactions detected by chromatin configuration capture(3C)-derived methods.To validate this method,short-range interactions in keratin-encoding gene(KRT)locus in topologically associated domain(TAD)were imaged by triple-color Tn5-FISH,indicating that Tn5-FISH is very useful to verify short-range chromatin interactions inside the contact domain and TAD.Therefore,Tn5-FISH can be a powerful molecular tool for the clinical detection of cytogenetic changes in numerous genetic diseases such as cancers.展开更多
基金support provided by the ARC through the ARC DP200101249 project.J.Feng would like to thank the computational resources provided by the High-Performance Computing Center of Qufu Normal University.D.Wang would like to acknowledge the National Natural Science Foundation of China(21903048,21971244,51932001,21931012,21590795)and National Key R&D Program of China(2018YFA0703504,2021YFB3802600).
文摘The effective utilization of solar energy for hydrogen production requires an abundant supply of thermodynamically active photo-electrons;however,the photocatalysts are generally impeded by insufficient light absorption and fast photocarrier recombination.Here,we report a multiple-regulated strategy to capture photons and boost photocarrier dynamics by devel-oping a broadband photocatalyst composed of defect engineered g-C_(3)N_(4)(DCN)and upconversion NaYF4:Yb^(3+),Tm^(3+)(NYF)nanocrystals.Through a precise defect engineering,the S dopants and C vacancies jointly render DCN with defect states to effectively extend the visible light absorption to 590 nm and boost photocarrier separation via a moderate electron-trapping ability,thus facilitating the subsequent re-absorption and utilization of upconverted photons/electrons.Importantly,we found a promoted interfacial charge polarization between DCN and NYF has also been achieved mainly due to Y-N interaction,which further favors the upconverted excited energy transfer from NYF onto DCN as verified both theoretically and experimentally.With a 3D architecture,the NYF@DCN catalyst exhibits a superior solar H2 evolution rate among the reported upconversion-based system,which is 19.3 and 1.5 fold higher than bulk material and DCN,respectively.This work provides an innovative strategy to boost solar utilization by using defect engineering and building up interaction between hetero-materials.
基金supported by the Research Council of Shiraz University of Medical Sciences,Shiraz,Iran.
文摘Biomedical investigations in nanotherapeutics and nanomedicine have recently intensified in pursuit of new therapies with improved efficacy.Quantum dots(QDs)are promising nanomaterials that possess a wide array of advantageous properties,including electronic properties,optical properties,and engineered biocompatibility under physiological conditions.Due to these characteristics,QDs are mainly used for biomedical labeling and theranostic(therapeutic-diagnostic)agents.QDs can be functionalized with ligands to facilitate their interaction with the immune system,specific IgE,and effector cell receptors.However,undesirable side effects such as hypersensitivity and toxicity may occur,requiring further assessment.This review systematically summarizes the potential uses of QDs in the allergy field.An overview of the definition and development of QDs is provided,along with the applications of QDs in allergy studies,including the detection of allergen-specific IgE(sIgE),food allergens,and sIgE in cellular tests.The potential treatment of allergies with QDs is also described,highlighting the toxicity and biocompatibility of these nanodevices.Finally,we discuss the current findings on the immunotoxicity of QDs.Several favorable points regarding the use of QDs for allergy diagnosis and treatment are noted.
基金support from the Australian Research Council(ARC)Future Fellowship Scheme(DJ,FT 130100517)the National Health and Medical Research Council(OS,APP1101258)the ARC Industry Transformational Research Hub Scheme(IH150100028).
文摘Nanoparticles have become new tools for cell biology imaging1,sub-cellular sensing2,super-resolution imaging3,4 and drug delivery5.Long-term 3D tracking of nanoparticles and their intracellular motions have advanced the understanding of endocytosis and exocytosis as well as of active transport processes6–8.The sophisticated operation of correlative optical-electron microscopy9,10 and scientific-grade cameras is often used to study intercellular processes.Nonetheless,most of these studies are still limited by the insufficient sensitivity for separating a single nanoparticle from a cluster of nanoparticles or their aggregates8,11,12.Here we report that our eyes can track a single fluorescent nanoparticle that emits over 4000 photons per 100 milliseconds under a simple microscope setup.By tracking a single nanoparticle with high temporal,spectral and spatial resolution,we show the measurement of the local viscosity of the intracellular environment.Moreover,beyond the colour domain and 3D position,we introduce excitation power density as the fifth dimension for our eyes to simultaneously discriminate multiple sets of single nanoparticles.
基金supported by the National Natural Science Foundation of China(Grants Nos.51672259,51720105015,51672265,21521092,51750110511,and 21872174)Key Research Program of Frontier Sciences of CAS(YZDY-SSWJSC018)+8 种基金the CAS-Croucher Funding Scheme for Joint Laboratories(CAS18204)the Scientific and Technological Department of Jilin Province(Grant No.20170414003GH)Project of Innovation-Driven Plan in Central South University(2017CX003)State Key Laboratory of Powder Metallurgy in Central South UniversityThousand Youth Talents Plan of ChinaHundred Youth Talents Program of HunanShenzhen Science and Technology Innovation Project(630)Jiangmen Innovative Research Team Program(2017)Major program of basic research and applied research of Guangdong Province(2017KZDXM083).
文摘Phosphor-converted white-light-emitting diodes(pc-WLED)have been extensively employed as solid-state lighting sources,which have a very important role in people’s daily lives.However,due to the scarcity of the red component,it is difficult to realize warm white light efficiently.Hence,red-emitting phosphors are urgently required for improving the illumination quality.In this work,we develop a novel orangish-red La_(4)GeO_(8):Bi^(3+) phosphor,the emission peak of which is located at 600 nm under near-ultraviolet(n-UV)light excitation.The full width at half maximum(fwhm)is 103 nm,the internal quantum efficiency(IQE)exceeds 88%,and the external quantum efficiency(EQE)is 69%.According to Rietveld refinement analysis and density functional theory(DFT)calculations,Bi^(3+) ions randomly occupy all La sites in orthorhombic La_(4)GeO_(8).Importantly,the oxygen-vacancy-induced electronic localization around the Bi3+ions is the main reason for the highly efficient orangish-red luminescence.These results provide a new perspective and insight from the local electron structure for designing inorganic phosphor materials that realize the unique luminescence performance of Bi^(3+) ions.
基金Science and Technology Innovation Commission of Shenzhen(KQTD20170810110913065,20200925174735005)Australia China Science and Research Fund Joint Research Centre for Point-of-Care Testing(ACSRF658277,SQ2017YFGH001190)ARC Laureate Fellowship Program(D.J.,FL210100180)。
文摘Although small EVs(sEVs)have been used widely as biomarkers in disease diagnosis,their heterogeneity at single EV level has rarely been revealed.This is because high-resolution characterization of sEV presents a major challenge,as their sizes are below the optical diffraction limit.Here,we report that upconversion nanoparticles(UCNPs)can be used for super-resolution profiling the molecular heterogeneity of sEVs.We show that Er3+-doped UCNPs has better brightness and Tm3+-doped UCNPs resulting in better resolution beyond diffraction limit.Through an orthogonal experimental design,the specific targeting of UCNPs to the tumour epitope on single EV has been cross validated,resulting in the Pearson’s R-value of 0.83 for large EVs and~65%co-localization double-positive spots for sEVs.Furthermore,super-resolution nanoscopy can distinguish adjacent UCNPs on single sEV with a resolution of as high as 41.9 nm.When decreasing the size of UCNPs from 40 to 27 nm and 18 nm,we observed that the maximum UCNPs number on single sEV increased from 3 to 9 and 21,respectively.This work suggests the great potentials of UCNPs approach“digitally”quantify the surface antigens on single EVs,therefore providing a solution to monitor the EV heterogeneity changes along with the tumour progression progress.
基金supported by the National Key Basic Research Program(973 Program,2012CB316503)the National Instrument Development Special Program(2013YQ03065102)+1 种基金the National Natural Science Foundation of China(31361163004,31327901,61475010 and 61428501)supported by UTD funds.
文摘Fluorescence polarization microscopy(FPM)aims to detect the dipole orientation of fluorophores and to resolve structural information for labeled organelles via wide-field or confocal microscopy.Conventional FPM often suffers from the presence of a large number of molecules within the diffraction-limited volume,with averaged fluorescence polarization collected from a group of dipoles with different orientations.Here,we apply sparse deconvolution and least-squares estimation to fluorescence polarization modulation data and demonstrate a super-resolution dipole orientation mapping(SDOM)method that resolves the effective dipole orientation from a much smaller number of fluorescent molecules within a sub-diffraction focal area.We further apply this method to resolve structural details in both fixed and live cells.For the first time,we show that different borders of a dendritic spine neck exhibit a heterogeneous distribution of dipole orientation.Furthermore,we illustrate that the dipole is always perpendicular to the direction of actin filaments in mammalian kidney cells and radially distributed in the hourglass structure of the septin protein under specific labelling.The accuracy of the dipole orientation can be further mapped using the orientation uniform factor,which shows the superiority of SDOM compared with its wide-field counterpart as the number of molecules is decreased within the smaller focal area.Using the inherent feature of the orientation dipole,the SDOM technique,with its fast imaging speed(at sub-second scale),can be applied to a broad range of fluorescently labeled biological systems to simultaneously resolve the valuable dipole orientation information with super-resolution imaging.
基金grants from The Hong Kong Research Grants Council(HKBU 22301615)from Hong Kong Baptist University(FRG 2/17-18/007).
文摘The optical thermometer has shown great promise for use in the fields of aeronautical engineering,environmental monitoring and medical diagnosis.Self-referencing lanthanide thermo-probes distinguish themselves because of their accuracy,calibration,photostability,and temporal dimension of signal.However,the use of conventional lanthanidedoped materials is limited by their poor reproducibility,random distance between energy transfer pairs and interference by energy migration,thereby restricting their utility.Herein,a strategy for synthesizing hetero-dinuclear complexes that comprise chemically similar lanthanides is introduced in which a pair of thermosensitive dinuclear complexes,cycTb-phEu and cycEu-phTb,were synthesized.Their structures were geometrically optimized with an internuclear distance of approximately 10.6Å.The sensitive linear temperature-dependent luminescent intensity ratios of europium and terbium emission over a wide temperature range(50–298 K and 10–200 K,respectively)and their temporal dimension responses indicate that both dinuclear complexes can act as excellent self-referencing thermometers.The energy transfer from Tb^(3+)to Eu^(3+)is thermally activated,with the most important pathway involving the ^(7)F_(1) Eu^(3+)J-multiplet at room temperature.The energy transfer from the antenna to Eu^(3+)was simulated,and it was found that the most important ligand contributions to the rate come from transfers to the Eu^(3+)upper states rather than direct ligand–metal transfer to 5D1 or 5D0.As the first molecular-based thermometer with clear validation of the metal ratio and a fixed distance between the metal pairs,these dinuclear complexes can be used as new materials for temperature sensing and can provide a new platform for understanding the energy transfer between lanthanide ions.
基金the National Natural Science Foundation of China(81890991,61705252,62025501,61729501,31971376)the State Key Research Development Program of China(2021YFE0201100,2017YFA0505503,2017YFC0110202)+3 种基金the Beijing Natural Science Foundation(JQ18019)CAS Interdisciplinary Innovation Team(JCTD-2020-04)Beijing Municipal Natural Science Foundation(Z200021)Shenzhen Science and Technology Program(KQTD20170810110913065).
文摘The orientation of fluorophores can reveal crucial information about the structure and dynamics of their associated subcellular organelles.Despite significant progress in super-resolution,fluorescence polarization microscopy remains limited to unique samples with relatively strong polarization modulation and not applicable to the weak polarization signals in samples due to the excessive background noise.Here we apply optical lock-in detection to amplify the weak polarization modulation with super-resolution.This novel technique,termed optical lock-in detection super-resolution dipole orientation mapping(OLID-SDOM),could achieve a maximum of 100 frames per second and rapid extraction of 2D orientation,and distinguish distance up to 50 nm,making it suitable for monitoring structural dynamics concerning orientation changes in vivo.OLID-SDOM was employed to explore the universal anisotropy of a large variety of GFP-tagged subcellular organelles,including mitochondria,lysosome,Golgi,endosome,etc.We found that OUF(Orientation Uniformity Factor)of OLID-SDOM can be specific for different subcellular organelles,indicating that the anisotropy was related to the function of the organelles,and OUF can potentially be an indicator to distinguish normal and abnormal cells(even cancer cells).Furthermore,dual-color super-resolution OLID-SDOM imaging of lysosomes and actins demonstrates its potential in studying dynamic molecular interactions.The subtle anisotropy changes of expanding and shrinking dendritic spines in live neurons were observed with real-time OLID-SDOM.Revealing previously unobservable fluorescence anisotropy in various samples and indicating their underlying dynamic molecular structural changes,OLID-SDOM expands the toolkit for live cell research.
基金funding support from ANU PhD student scholarship,China Scholarship Council,Australian Research Council(ARC,numbers DE140100805 and DP180103238)ARC Centre of Excellence in Future Low-Energy Electronics Technologies(project number CE170100039)ARC Centre of Excellence in Quantum Computation and Communication Technology(project number CE170100012).
文摘Long-range and fast transport of coherent excitons is important for the development of high-speed excitonic circuits and quantum computing applications.However,most of these coherent excitons have only been observed in some low-dimensional semiconductors when coupled with cavities,as there are large inhomogeneous broadening and dephasing effects on the transport of excitons in their native states in materials.Here,by confining coherent excitons at the 2D quantum limit,we first observed molecular aggregation-enabled‘supertransport’of excitons in atomically thin two-dimensional(2D)organic semiconductors between coherent states,with a measured high effective exciton diffusion coefficient of ~346.9 cm^(2)/s at room temperature.This value is one to several orders of magnitude higher than the values reported for other organic molecular aggregates and low-dimensional inorganic materials.Without coupling to any optical cavities,the monolayer pentacene sample,a very clean 2D quantum system(~1.2 nm thick)with high crystallinity(J-type aggregation)and minimal interfacial states,showed superradiant emission from Frenkel excitons,which was experimentally confirmed by the temperature-dependent photoluminescence(PL)emission,highly enhanced radiative decay rate,significantly narrowed PL peak width and strongly directional in-plane emission.The coherence in monolayer pentacene samples was observed to be delocalised over~135 molecules,which is significantly larger than the values(a few molecules)observed for other organic thin films.In addition,the supertransport of excitons in monolayer pentacene samples showed highly anisotropic behaviour.Our results pave the way for the development of future high-speed excitonic circuits,fast OLEDs,and other optoelectronic devices.
基金Australia China Science and Research Fund Joint Research Centre for Point-of-Care Testing(ACSRF658277,SQ2017YFGH001190)Science and Technology Innovation Commission of Shenzhen(KQTD20170810110913065)Australian Research Council Laureate Fellowship Program(D.J.,FL210100180).
文摘Nowadays,viral infections are one of the greatest challenges for medical sciences and human society.While antiviral compounds and chemical inactivation remain inadequate,physical approaches based on irradiation provide new potentials for prevention and treatment of viral infections,without the risk of drug resistance and other unwanted side effects.Light across the electromagnetic spectrum can inactivate the virions using ionizing and non-ionizing radiations.This review highlights the anti-viral utility of radiant methods from the aspects of ionizing radiation,including high energy ultraviolet,gamma ray,X-ray,and neutron,and non-ionizing photo-inactivation,including lasers and blue light.
基金supported by the National Instrument Development Special Program(2013YQ03065102)the‘973’Major State Basic Research Development Program of China(2011CB809101)+2 种基金the Natural Science Foundation of China(31327901,61475010,61428501)the Australian Research Council Centre of Excellence for Nanoscale BioPhotonics(CE140100003)provided by the National Institute of Health(GM094198 to PJS).
文摘Axial excitation confinement beyond the diffraction limit is crucial to the development of next-generation,super-resolution microscopy.STimulated Emission Depletion(STED)nanoscopy offers lateral super-resolution using a donut-beam depletion,but its axial resolution is still over 500 nm.Total internal reflection fluorescence microscopy is widely used for single-molecule localization,but its ability to detect molecules is limited to within the evanescent field of~100 nm from the cell attachment surface.We find here that the axial thickness of the point spread function(PSF)during confocal excitation can be easily improved to 110 nm by replacing the microscopy slide with a mirror.The interference of the local electromagnetic field confined the confocal PSF to a 110-nm spot axially,which enables axial super-resolution with all laser-scanning microscopes.Axial sectioning can be obtained with wavelength modulation or by controlling the spacer between the mirror and the specimen.With no additional complexity,the mirror-assisted excitation confinement enhanced the axial resolution six-fold and the lateral resolution two-fold for STED,which together achieved 19-nm resolution to resolve the inner rim of a nuclear pore complex and to discriminate the contents of 120 nm viral filaments.The ability to increase the lateral resolution and decrease the thickness of an axial section using mirror-enhanced STED without increasing the laser power is of great importance for imaging biological specimens,which cannot tolerate high laser power.
文摘Scientists are known as the idea explorers,technology inventors and visionaries for the great benefits of our end-users and society.They are optimistic,realistic and scientifically rigorous.The way for them to create new ideas and technologies can be through their intuitions and others’guidance and inspirations.Therefore scientific publishing plays an essential role in effective communications and knowledge advancements.For the past decade,rapid growth occurred in our science communities and the number of research outputs.Merely pursuing quantity of publishing may be in lack of satisfaction,given the large volume of information produced becomes overwhelming to our early career researchers,students or cross-disciplinary researchers.Top-tier journals should stay more closely connected with our most creative authors and influential research leaders,and find ways to boost more interdisciplinary discussions and inspire creative thoughts and practice.
基金This work was supported in part by the State Key Research Development Program of China(2017YFA0505503)the National Natural Science Foundation of China(81890991 and 31671383)+4 种基金Beijing Advanced Innovation Center for Structural Bio logy,Tsinghua University(100300001)the fund from Foshan-Tsinghua Innovation Special Fund(FTISF,2019THFS0141)to J.G.,the National Natural Science Foundation of China(31871444)the program for Guangdong Introducing Innovative and Entrepreneurial Teams(2016ZT06S029)to J.W.Australia China Science and Research Fund Joint Research Centre for POCT(ACSRF65827)Shenzhen Science and Technology Program(KQTD 20170810110913065)to D.J.
文摘There is an increasing interest in understanding how three-dimensional(3D)organization of the genome is regulated.Different strategies have been employed to identify genome-wide chromatin interactions.However,due to current limitations in resolving genomic contacts,visualization and validation of these genomic loci with sub-kilobase resolution remain unsolved to date.Here,we describe Tn5 transposase-based Fluorescencein situhybridization(Tn5-FISH),a PCR-based,cost-effective imaging method,which can co-localize the genomic loci with sub-kilobase resolution,dissect genome architecture,and verify chromatin interactions detected by chromatin configuration capture(3C)-derived methods.To validate this method,short-range interactions in keratin-encoding gene(KRT)locus in topologically associated domain(TAD)were imaged by triple-color Tn5-FISH,indicating that Tn5-FISH is very useful to verify short-range chromatin interactions inside the contact domain and TAD.Therefore,Tn5-FISH can be a powerful molecular tool for the clinical detection of cytogenetic changes in numerous genetic diseases such as cancers.
