The emission microscopy （EMMI） test is proposed as an effective method to control the polysilicon over-etching time of advanced CMOS processing combined with a novel test structure, named a poly-edge structure. From...The emission microscopy （EMMI） test is proposed as an effective method to control the polysilicon over-etching time of advanced CMOS processing combined with a novel test structure, named a poly-edge structure. From the values of the breakdown voltage （Vbd） of MOS capacitors （poly-edge structure） ,it was observed that,with for the initial polysilicon etching-time, almost all capacitors in one wafer failed under the initial failure model. With the increase of polysilicon over-etching time, the number of the initial failure capacitors decreased. Finally, no initial failure capacitors were observed after the polysilicon over-etching time was increased by 30s. The breakdown samples with the initial failure model and intrinsic failure model underwent EMMI tests. The EMMI test results show that the initial failure of capacitors with poly-edge structures was due to the bridging effect between the silicon substrate and the polysilicon gate caused by the residual polysilicon in the ditch between the shallow-trench isolation region and the active area, which will short the polysilicon gate with silicon substrate after the silicide process.展开更多
Nano-scale chemical inhomogeneity in surface oxide films formed on a V-and N-containing martensite stainless steel and tempering heating induced changes are investigated by a combination of synchrotron-based hard X-ra...Nano-scale chemical inhomogeneity in surface oxide films formed on a V-and N-containing martensite stainless steel and tempering heating induced changes are investigated by a combination of synchrotron-based hard X-ray Photoelectron emission spectroscopy(HAXPES)and microscopy(HAXPEEM)as well as microscopic X-ray absorption spectroscopy(μ-XAS)techniques.The results reveal the inhomogeneity in the oxide films on the micron-sized Cr_(2)N-and VN-type particles,while the inhomogeneity on the martensite matrix phase exists due to localised formation of nano-sized tempering nitride particles at 600℃.The oxide film formed on Cr_(2)N-type particles is rich in Cr_(2)O_(3) compared with that on the martensite matrix and VN-type particles.With the increase of tempering temperature,Cr_(2)O_(3) formation is faster for the oxidation of Cr in the martensite matrix than the oxidation of Cr nitride-rich particles.展开更多
We propose dynamic terahertz(THz) emission microscopy(DTEM) to visualize temporal–spatial dynamics of photoexcited carriers in electronic materials. DTEM utilizes THz pulses emitted from a sample by probe pulses irra...We propose dynamic terahertz(THz) emission microscopy(DTEM) to visualize temporal–spatial dynamics of photoexcited carriers in electronic materials. DTEM utilizes THz pulses emitted from a sample by probe pulses irradiated after pump pulse irradiation to perform time-resolved two-dimensional mapping of the THz pulse emission, reflecting various carrier dynamics. Using this microscopy, we investigated carrier dynamics in the gap region of low-temperature-grown Ga As and semi-insulating Ga As photoconductive switches of the identical-dipole type. The observed DTEM images are well explained by the change in the electric potential distribution between the electrodes caused by the screening effect of the photoexcited electron-hole pairs.展开更多
In this paper,we propose a new fluorescence emission difference microscopy(FED)technique based on polarization modulation.An electro-optical modulator(EOM)is used to switch the excitation beam between the horizontal a...In this paper,we propose a new fluorescence emission difference microscopy(FED)technique based on polarization modulation.An electro-optical modulator(EOM)is used to switch the excitation beam between the horizontal and vertical polarization states at a high frequency,which leads to solid-and donut-shaped beams after spatial light modulation.Experiment on the fluorescent nanoparticles demonstrates that the proposed method can achieve~λ=4 spatial resolution.Using the proposed system,the dynamic imaging of subcellular structures in living cells over time is achieved.展开更多
Hematologic malignancies are one of the most common malignant tumors caused by the clonal proliferation and differentiation of hematopoietic and lymphoid stem cells.The examination of bone marrow cells combined with i...Hematologic malignancies are one of the most common malignant tumors caused by the clonal proliferation and differentiation of hematopoietic and lymphoid stem cells.The examination of bone marrow cells combined with immunodeficiency typing is of great significance to the diagnostic type,treatment and prognosis of hematologic malignancies.Super-resolution fluorescence microscopy(SRM)is a special kind of optical microscopy technology,which breaks the resolution limit and was awarded the Nobel Prize in Chemistry in 2014.With the development of SRM,many related technologies have been applied to the diagnosis and treatment of clinical diseases.It was reported that a major type of SRM technique,single molecule localization microscopy(SMLM),is more sensitive than flow cytometry(FC)in detecting cell membrane antigens'expression,thus enabling better chances in detecting antigens on hematopoietic cells than traditional analytic tools.Furthermore,SRM may be applied to clinical pathology and may guide precision medicine and personalized medicine for clone hematopoietic cell diseases.In this paper,we mainly discuss the application of SRM in clone hematological malignancies.展开更多
Optical microscopy promises researchers to soe most tiny substances directly.However,the resolution of conventional microscopy is resticted by the diffraction limit.This makes it a challenge to observe subcellular pro...Optical microscopy promises researchers to soe most tiny substances directly.However,the resolution of conventional microscopy is resticted by the diffraction limit.This makes it a challenge to observe subcellular processes happened in nanoscale.The development of super-resolution microscopy provides a solution to this challenge.Here,we briefly review several commonly used super-resolution techniques,explicating their basic principles and applications in biological science,especially in neuroscience.In addition,characteristics and limitations of each techrique are compared to provide a guidance for biologists to choose the most suitable tool.展开更多
The authors presented a facile approach to prepare highly-ordered sub-micrometer scaled cylindrical diamond arrays based on a chemical vapor deposition method,where the accurate control of the style of crystal seeds d...The authors presented a facile approach to prepare highly-ordered sub-micrometer scaled cylindrical diamond arrays based on a chemical vapor deposition method,where the accurate control of the style of crystal seeds dispersion and the growth time are very crucial.The as-prepared diamond array showed good conductivity which was originated from the proper boron doping,and moreover,it exhibited good field emission property with low turn-on field and high emission current.Importantly,this approach can be easily applied to the preparation of various micro-patterned one-dimensional diamond arrays.展开更多
The mechanical properties of biological fluids serve as early indicators of disease,offering valuable insights into complex physiological and pathological processes.However,the existing technologies struggle to achiev...The mechanical properties of biological fluids serve as early indicators of disease,offering valuable insights into complex physiological and pathological processes.However,the existing technologies struggle to achieve high-throughput measurement,limiting their widespread applications in disease diagnosis.Here,we propose laser-emission vibrational microscopy of microdroplets for high-throughput measurement of the intrinsic mechanical properties of fluids.The microdroplet array supporting high Q-factor(104)whispering gallery modes(WGM)lasing was massively fabricated on a superhydrophobic surface with inkjet printing.Ultrasound was employed to actuate the mechanical vibrations of the microdroplets,and the vibration amplitude was quantified using time-resolved laser spectra.We found that the stimulus-response of the laser emission is strongly dependent on the liquid viscosity.Fast mapping of the microdroplets’viscosities was achieved by stage scanning.High-throughput screening of hyperlipidemia disease was also demonstrated by performing over 2000 measurements within 25 min.Thanks to the small volume of the microdroplets,a single drop of blood can support over seven million measurements.The high-throughput ability and small sample consumption make it a promising tool for clinical diagnoses based on mechanical properties.展开更多
Lanthanide-doped upconversion nanoparticles enable upconversion stimulated emission depletion microscopy with high photostability and low-intensity near-infrared continuous-wave lasers.Controlling energy transfer dyna...Lanthanide-doped upconversion nanoparticles enable upconversion stimulated emission depletion microscopy with high photostability and low-intensity near-infrared continuous-wave lasers.Controlling energy transfer dynamics in these nanoparticles is crucial for super-resolution microscopy with minimal laser intensities and high photon budgets.However,traditional methods neglect the spatial distribution of lanthanide ions and its effect on energy transfer dynamics.Here,we introduce topology-driven energy transfer networks in lanthanide-doped upconversion nanoparticles for upconversion stimulated emission depletion microscopy with reduced laser intensities,maintaining a high photon budget.Spatial separation of Yb^(3+)sensitizers and Tm^(3+)emitters in 50-nm core-shell nanoparticles enhance energy transfer dynamics for super-resolution microscopy.Topology-dependent energy migration produces strong 450-nm upconversion luminescence under low-power 980-nm excitation.Enhanced cross-relaxation improves optical switching efficiency,achieving a saturation intensity of 0.06 MW cm^(−2) under excitation at 980 nm and depletion at 808 nm.Super-resolution imaging with a 65-nm lateral resolution is achieved using intensities of 0.03 MW cm^(−2) for a Gaussian-shaped excitation laser at 980 nm and 1 MW cm^(−2) for a donut-shaped depletion laser at 808 nm,representing a 10-fold reduction in excitation intensity and a 3-fold reduction in depletion intensity compared to conventional methods.These findings demonstrate the potential of harnessing topology-dependent energy transfer dynamics in upconversion nanoparticles for advancing low-power super-resolution applications.展开更多
With the consideration of slip deformation mechanism and various slip systems of body centered cubic （BCC） metals, Taylor-type and finite element polycrystal models were embedded into the commercial finite element c...With the consideration of slip deformation mechanism and various slip systems of body centered cubic （BCC） metals, Taylor-type and finite element polycrystal models were embedded into the commercial finite element code ABAQUS to realize crystal plasticity finite element modeling, based on the rate dependent crystal constitutive equations. Initial orientations measured by electron backscatter diffraction （EBSD） were directly input into the crystal plasticity finite element model to simulate the develop- ment of rolling texture of interstitial-free steel （IF steel） at various reductions. The modeled results show a good agreement with the experimental results. With increasing reduction, the predicted and experimental rolling textures tend to sharper, and the results simulated by the Taylor-type model are stronger than those simulated by finite element model.＇Conclusions are obtained that rolling textures calculated with 48 { 110} 〈 111 〉＋ { 112 } 〈 111〉＋ { 123 } 〈 111 〉 slip systems are more approximate to EBSD results.展开更多
Tamusu mudstone formation, located in the Alxa area in western Inner Mongolia, is considered a potential host formation for high-level radioactive waste(HLW) underground disposal in China. In this study, complementary...Tamusu mudstone formation, located in the Alxa area in western Inner Mongolia, is considered a potential host formation for high-level radioactive waste(HLW) underground disposal in China. In this study, complementary analyses with X-ray diffraction(XRD), field emission scanning electron microscopy(FE-SEM), mercury intrusion porosimetry(MIP), and N_(2) physisorption isotherm were conducted on the Tamusu mudstone to characterize its physical characteristics and microstructural features, such as mineral compositions and pore structure. Several minerals, including carbonates, feldspar, clays and analcime, were identified in Tamusu mudstone by XRD. Images from FE-SEM show that pores in the Tamusu mudstone were dominantly on nanometer scale and generally located within their mineral matrix or at the interface with non-porous minerals. The combination of the MIP and N_2 physisorption curves indicated that the Tamusu mudstone has diverse pore sizes, a porosity varying from 2.34% to 2.84%, and a total pore volume in the range of 0.0065—0.0222 cm^(3)/g with the average pore diameter ranging from 9.6 nm to 19.23 nm. The specific surface area measured by MIP(2.572—5.861 m^(2)/g) was generally higher than that by N_(2) physisorption(1.29—3.04 m^(2)/g), due to the pore network effect, pore shape(e.g. ink-bottle shape), or technique limits. The results related to pore information can be applied as an input in the future to model single-or multi-phase fluid flow and the transport of radionuclides in porous geomedium by migration and diffusion.展开更多
Far-¯eld°uorescence microscopy has made great progress in the spatial resolution,limited by light diffraction,since the super-resolution imaging technology appeared.And stimulated emission depletion(STED)mic...Far-¯eld°uorescence microscopy has made great progress in the spatial resolution,limited by light diffraction,since the super-resolution imaging technology appeared.And stimulated emission depletion(STED)microscopy and structured illumination microscopy(SIM)can be grouped into one class of the super-resolution imaging technology,which use pattern illumination strategy to circumvent the di®raction limit.We simulated the images of the beads of SIM imaging,the intensity distribution of STED excitation light and depletion light in order to observe effects of the polarized light on imaging quality.Compared to¯xed linear polarization,circularly polarized light is more suitable for SIM on reconstructed image.And right-handed circular polarization(CP)light is more appropriate for both the excitation and depletion light in STED system.Therefore the right-handed CP light would be the best candidate when the SIM and STED are combined into one microscope.Good understanding of the polarization will provide a reference for the patterned illumination experiment to achieve better resolution and better image quality.展开更多
Excellent magnetic properties in ferrites are required for high-frequency applications and for wastewater treatment. Thus, the present study shows the comparison of magnetic and structural properties of Nd and Sm subs...Excellent magnetic properties in ferrites are required for high-frequency applications and for wastewater treatment. Thus, the present study shows the comparison of magnetic and structural properties of Nd and Sm substituted Ni-Zn-Bi ferrites with the series Ni_(0.5)Zn_(0.5)Bi_(0.04)Nd_(x)Fe_(1.96-x)O_4(with step size 0.002)and Ni_(0.5)Zn_(0.5)Bi_(0.04)Sm_(x)Fe_(1.96-x)O_4(with step size 0.02) prepared using citrate precursor method. The impact of the substitution of rare earth ions(Nd and Sm) on magnetic properties of the synthesized samples is observed using a vibrating sample magnetometer(VSM). The saturation magnetization values enhance considerably from 52 to 58 emu/g for Nd^(3+)ions and 39 to 57 emu/g for Sm^(3+) ions, thus, making these materials magnetically hard. Further, the higher value of coercivity is also observed ranging from133 to 167 Oe for Nd^(3+)ions and 81 to 155 Oe for Sm^(3+) ions. The shape of hysteresis loops indicates a super paramagnetic and ferromagnetic behavior in the obtained samples. The squareness ratio value is<0.5, suggesting the uniaxial anisotropy of particles and hence, these ferrites are suitable for microwaveabsorbing and in permanent magnetic materials. The X-ray diffraction(XRD) pattern shows the formation of pure cubic crystallites, where, lattice parameters range from 0.840 to 0.839 nm and from 0.838to 0.839 nm for Nd^(3+)and Sm^(3+) ions substitution, respectively. The crystallite size ranges between 28.63to 29.89 nm and 18.33 to 26.23 nm, for substitution of Nd^(3+)and Sm^(3+) ions, respectively. Field emission scanning electron microscopy(FESEM) shows the formation of homogeneous grains, whereas, energy dispersive spectrometer(EDS) counts describe the purity of the samples. The Sm concentration x = 0.10has the maximum surface area with value of 42.6 m^(2)/g which proves to be having good data storage application due to high surface area. The zero-field cooled(ZFC) and field cooled(FC) data show that Nddoped Ni-Zn-Bi nanoferrites show superparamagnetic behaviour in the room temperature range which makes them suitable for practical applications.展开更多
Synapses are essential units for the flow of information in the brain.Over the last 70 years,synapses have been widely studied in multiple animal models including worms,fruit flies,and rodents.In comparison,the study ...Synapses are essential units for the flow of information in the brain.Over the last 70 years,synapses have been widely studied in multiple animal models including worms,fruit flies,and rodents.In comparison,the study of human synapses has evolved significantly slower,mainly because of technical limitations.However,three novel methods allowing the analysis of molecular,morphological,and functional properties of human synapses may expand our knowledge of the human brain.Here,we briefly describe these methods,and evaluate how the information provided by each unique approach may contribute to the functional and anatomical analysis of the synaptic component of human brain circuitries.In particular,using tissue from cryopreserved human brains,synaptic plasticity can be studied in isolated synaptosomes by fluorescence analysis of single-synapse long-term potentiation（FASS-LTP）,and subpopulations of synapses can be thoroughly assessed in the ribbons of brain tissue by array tomography（AT）.Currently,it is also possible to quantify synaptic density in the living human brain by positron emission tomography（PET）,using a novel synaptic radio-ligand.Overall,data provided by FASS-LTP,AT,and PET may significantly contribute to the global understanding of synaptic structure and function in both healthy and diseased human brains,thus directly impacting translational research.展开更多
The significant role of telomeres in cells has attracted much attention since they were discovered.Fluorescence imaging is an effective method to study subcellular structures like telomeres.However,the diffraction lim...The significant role of telomeres in cells has attracted much attention since they were discovered.Fluorescence imaging is an effective method to study subcellular structures like telomeres.However,the diffraction limit of traditional optical microscope hampers further investigation on them.Recent progress on superresolution fluorescence microscopy has broken this limit.In this work,we used stimulated emission depletion(STED) microscope to observe fluorescence-labeled telomeres in interphase cell nuclei.The results showed that the size of fluorescent puncta representing telomeres under the STED microscope was much smaller than that under the confocal microscope.Two adjacent telomeres were clearly separated via STED imaging,which could hardly be discriminated by confocal microscopy due to the diffraction limit.We conclude that STED microscope is a more powerful tool that enable us to obtain detailed information about telomeres.展开更多
Stimulated emission depletion(STED)microscopy requires fluorescent probes to exhibit high brightness,good photostability,a sensitive optical depletion response,and narrow spectral features.There are great interests in...Stimulated emission depletion(STED)microscopy requires fluorescent probes to exhibit high brightness,good photostability,a sensitive optical depletion response,and narrow spectral features.There are great interests in using polymer dots(Pdots)for STED imaging due to their exceptional brightness and photobleaching resistance.However,the conven-tional Pdots either suffer from broad spectra or an unsatisfactory STED response.Herein,we developed a general method for obtaining Pdots with desirable optical properties for STED microscopy.Speciically,boron.dipyrromethene(BODIpY)chromophores were grafted on to a polystyrene backbone to obtain polymers with narrow spectral profiles.The grafting ratio was precisely controlled to minimize aggregation-induced quenching.Conjugating BODIpYs to side chains reduced interactions between the chromophores,resulting in a long excited state lifetime,which is critical for obtaining complete fluorescence depletion.Using this strategy,we synthesized three-color Pdots with narrow spectra features.Compared to directly encapsulating BODIpYs into nanoparticles,our strategy achieved 2-10 times higher single-particle brightness.We used Pdots for single-particle,cellular,and tissular STED imaging.The Pdots showed high spatial resolutions and could clearly resolve subdiffraction-limit structures in cells and tissue sections,indicating great application potential in in vitro diagnostics and biomedical imaging applications.展开更多
Highly crystallized mullite has been achieved at temperatures of 1100℃and 1400℃by sol-gel technique in presence of titanium and strontium ions of different concentrations:G_(0)=0 M,G_(1)=0.002 M,G_(2)=0.01 M,G_(3)=0...Highly crystallized mullite has been achieved at temperatures of 1100℃and 1400℃by sol-gel technique in presence of titanium and strontium ions of different concentrations:G_(0)=0 M,G_(1)=0.002 M,G_(2)=0.01 M,G_(3)=0.02 M,G_(4)=0.1 M,G_(5)=0.2 M and G6=0.5 M.X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),field emission scanning electron microscopy(FESEM),LCR meter characterized the samples.Mullite formation was found to depend on the concentration of the ions.The dielectric properties(dielectric constant,loss tangent and AC conductivity)of the composites have been measured,and their variation with increasing frequency and concentration of the doped metals was investigated.All the experiments were performed at room temperature.The composites showed maximum dielectric constants of 24.42 and 37.6 at 1400℃of 0.01 M concentration for titanium and strontium ions at 2 MHz,respectively.Due to the perfect nature of the doped mullite,it can be used for the fabrication of high charge storing capacitors and also as ceramic capacitors in the pico range.展开更多
Mammalian mitochondrial electron transport chain complexes are the most important and complicated protein machinery in mitochondria.Although this system has been studied for more than a century,its composition and mol...Mammalian mitochondrial electron transport chain complexes are the most important and complicated protein machinery in mitochondria.Although this system has been studied for more than a century,its composition and molecular mechanism are still largely unknown.Here we report the high-resolution cryo-electron microscopy(Cryo-EM)structures of porcine respiratory chain megacomplex-Ⅰ_(2)Ⅲ_(2)Ⅳ_(2)(MCⅠ_(2)Ⅲ_(2)Ⅳ_(2))in five different conformations,including State 1,State 2,Mid 1,Mid 2,and Mid 3.High-resolution Cryo-EM imaging,combined with super-resolution gated stimulated emission depletion microscopy(gSTED),strongly supports the formation of MCⅠ_(2)Ⅲ_(2)Ⅳ_(2)in live cells.Each MCⅠ_(2)Ⅲ_(2)Ⅳ_(2)structure contains 141 subunits(70 different kinds of peptides,2.9 MDa)in total with 240 transmembrane helices.The mutual influence among CⅠ,CⅢ,and CⅣshown in the MCⅠ_(2)Ⅲ_(2)Ⅳ_(2)structure suggests this megacomplex could act as an integral unit in electron transfer and proton pumping.The conformational changes from different states suggest a plausible regulatory mechanism for the MCⅠ_(2)Ⅲ_(2)Ⅳ_(2)activation/deactivation process.展开更多
文摘The emission microscopy （EMMI） test is proposed as an effective method to control the polysilicon over-etching time of advanced CMOS processing combined with a novel test structure, named a poly-edge structure. From the values of the breakdown voltage （Vbd） of MOS capacitors （poly-edge structure） ,it was observed that,with for the initial polysilicon etching-time, almost all capacitors in one wafer failed under the initial failure model. With the increase of polysilicon over-etching time, the number of the initial failure capacitors decreased. Finally, no initial failure capacitors were observed after the polysilicon over-etching time was increased by 30s. The breakdown samples with the initial failure model and intrinsic failure model underwent EMMI tests. The EMMI test results show that the initial failure of capacitors with poly-edge structures was due to the bridging effect between the silicon substrate and the polysilicon gate caused by the residual polysilicon in the ditch between the shallow-trench isolation region and the active area, which will short the polysilicon gate with silicon substrate after the silicide process.
基金supported by the Vinnova(project number 2020-03778)supported by the Swedish Research Council(Vetenskapsradet,project number 2021-04157).
文摘Nano-scale chemical inhomogeneity in surface oxide films formed on a V-and N-containing martensite stainless steel and tempering heating induced changes are investigated by a combination of synchrotron-based hard X-ray Photoelectron emission spectroscopy(HAXPES)and microscopy(HAXPEEM)as well as microscopic X-ray absorption spectroscopy(μ-XAS)techniques.The results reveal the inhomogeneity in the oxide films on the micron-sized Cr_(2)N-and VN-type particles,while the inhomogeneity on the martensite matrix phase exists due to localised formation of nano-sized tempering nitride particles at 600℃.The oxide film formed on Cr_(2)N-type particles is rich in Cr_(2)O_(3) compared with that on the martensite matrix and VN-type particles.With the increase of tempering temperature,Cr_(2)O_(3) formation is faster for the oxidation of Cr in the martensite matrix than the oxidation of Cr nitride-rich particles.
文摘We propose dynamic terahertz(THz) emission microscopy(DTEM) to visualize temporal–spatial dynamics of photoexcited carriers in electronic materials. DTEM utilizes THz pulses emitted from a sample by probe pulses irradiated after pump pulse irradiation to perform time-resolved two-dimensional mapping of the THz pulse emission, reflecting various carrier dynamics. Using this microscopy, we investigated carrier dynamics in the gap region of low-temperature-grown Ga As and semi-insulating Ga As photoconductive switches of the identical-dipole type. The observed DTEM images are well explained by the change in the electric potential distribution between the electrodes caused by the screening effect of the photoexcited electron-hole pairs.
基金supported in part by the National Natural Science Foundation of China(61827825,62125504,and 61735017)Major Program of the Natural Science Foundation of Zhejiang Province(LD21F050002)+2 种基金Key Research and Development Program of Zhejiang Province(2020C01116)Zhejiang Lab(2020MC0AE01)China Postdoctoral Science Foundation(BX2021272).
文摘In this paper,we propose a new fluorescence emission difference microscopy(FED)technique based on polarization modulation.An electro-optical modulator(EOM)is used to switch the excitation beam between the horizontal and vertical polarization states at a high frequency,which leads to solid-and donut-shaped beams after spatial light modulation.Experiment on the fluorescent nanoparticles demonstrates that the proposed method can achieve~λ=4 spatial resolution.Using the proposed system,the dynamic imaging of subcellular structures in living cells over time is achieved.
基金This work was supported by the Innovation Fund of WNLO(2018WNLOKF023)the Start-up Fund of Hainan University(KYQD(ZR)-20077).
文摘Hematologic malignancies are one of the most common malignant tumors caused by the clonal proliferation and differentiation of hematopoietic and lymphoid stem cells.The examination of bone marrow cells combined with immunodeficiency typing is of great significance to the diagnostic type,treatment and prognosis of hematologic malignancies.Super-resolution fluorescence microscopy(SRM)is a special kind of optical microscopy technology,which breaks the resolution limit and was awarded the Nobel Prize in Chemistry in 2014.With the development of SRM,many related technologies have been applied to the diagnosis and treatment of clinical diseases.It was reported that a major type of SRM technique,single molecule localization microscopy(SMLM),is more sensitive than flow cytometry(FC)in detecting cell membrane antigens'expression,thus enabling better chances in detecting antigens on hematopoietic cells than traditional analytic tools.Furthermore,SRM may be applied to clinical pathology and may guide precision medicine and personalized medicine for clone hematopoietic cell diseases.In this paper,we mainly discuss the application of SRM in clone hematological malignancies.
基金support from National Basic Research Program of China (973 Program) (2015CB352005)National Natural Science Foundation of China (No.6142780065,31571110,81527901)+1 种基金Natural Science Foundation of Zhejiang Province of China (No.Y16F050002)the Fundamental Research Funds for the Central Universities.
文摘Optical microscopy promises researchers to soe most tiny substances directly.However,the resolution of conventional microscopy is resticted by the diffraction limit.This makes it a challenge to observe subcellular processes happened in nanoscale.The development of super-resolution microscopy provides a solution to this challenge.Here,we briefly review several commonly used super-resolution techniques,explicating their basic principles and applications in biological science,especially in neuroscience.In addition,characteristics and limitations of each techrique are compared to provide a guidance for biologists to choose the most suitable tool.
基金Supported by the National Natural Science Foundation of China(Nos.20601005,20125102 and 20571077)the National Basic Research Program of China(Nos.2010CB934700,2009CB930404 and 2007CB936403)+1 种基金the Special Fund for Special Prize of the President Awardthe Chinese Postdoctoral Fund and K. C. Wong Education Foundation
文摘The authors presented a facile approach to prepare highly-ordered sub-micrometer scaled cylindrical diamond arrays based on a chemical vapor deposition method,where the accurate control of the style of crystal seeds dispersion and the growth time are very crucial.The as-prepared diamond array showed good conductivity which was originated from the proper boron doping,and moreover,it exhibited good field emission property with low turn-on field and high emission current.Importantly,this approach can be easily applied to the preparation of various micro-patterned one-dimensional diamond arrays.
基金supported by the National Natural Science Foundation of China(Grant No.62375030,82241059,82125022)the Fundamental Research Funds for the Central Universities(Grant No.2024CDJYXTD-004)the Yunnan Province Major Science and Technology Special Project(Grant No.202302AA310039).
文摘The mechanical properties of biological fluids serve as early indicators of disease,offering valuable insights into complex physiological and pathological processes.However,the existing technologies struggle to achieve high-throughput measurement,limiting their widespread applications in disease diagnosis.Here,we propose laser-emission vibrational microscopy of microdroplets for high-throughput measurement of the intrinsic mechanical properties of fluids.The microdroplet array supporting high Q-factor(104)whispering gallery modes(WGM)lasing was massively fabricated on a superhydrophobic surface with inkjet printing.Ultrasound was employed to actuate the mechanical vibrations of the microdroplets,and the vibration amplitude was quantified using time-resolved laser spectra.We found that the stimulus-response of the laser emission is strongly dependent on the liquid viscosity.Fast mapping of the microdroplets’viscosities was achieved by stage scanning.High-throughput screening of hyperlipidemia disease was also demonstrated by performing over 2000 measurements within 25 min.Thanks to the small volume of the microdroplets,a single drop of blood can support over seven million measurements.The high-throughput ability and small sample consumption make it a promising tool for clinical diagnoses based on mechanical properties.
基金supported by the National Key Research and Development program of China(Grant No.2022YFB2804301 and Grant No.2021YFB2802000)the Science and Technology Commission of Shanghai Municipality(Grant No.21DZ1100500)+3 种基金the Shanghai Municipal Science and Technology Major Project,the Shanghai Frontiers Science Center Program(2021-2025 No.20)the National Natural Science Foundation of China(Grant No.61975123 and Grant No.62205208)the China Postdoctoral Science Foundation(3722904001,3722904006)the Shanghai Super Postdoctoral Incentive Scheme(5B22904002,5B22904006).
文摘Lanthanide-doped upconversion nanoparticles enable upconversion stimulated emission depletion microscopy with high photostability and low-intensity near-infrared continuous-wave lasers.Controlling energy transfer dynamics in these nanoparticles is crucial for super-resolution microscopy with minimal laser intensities and high photon budgets.However,traditional methods neglect the spatial distribution of lanthanide ions and its effect on energy transfer dynamics.Here,we introduce topology-driven energy transfer networks in lanthanide-doped upconversion nanoparticles for upconversion stimulated emission depletion microscopy with reduced laser intensities,maintaining a high photon budget.Spatial separation of Yb^(3+)sensitizers and Tm^(3+)emitters in 50-nm core-shell nanoparticles enhance energy transfer dynamics for super-resolution microscopy.Topology-dependent energy migration produces strong 450-nm upconversion luminescence under low-power 980-nm excitation.Enhanced cross-relaxation improves optical switching efficiency,achieving a saturation intensity of 0.06 MW cm^(−2) under excitation at 980 nm and depletion at 808 nm.Super-resolution imaging with a 65-nm lateral resolution is achieved using intensities of 0.03 MW cm^(−2) for a Gaussian-shaped excitation laser at 980 nm and 1 MW cm^(−2) for a donut-shaped depletion laser at 808 nm,representing a 10-fold reduction in excitation intensity and a 3-fold reduction in depletion intensity compared to conventional methods.These findings demonstrate the potential of harnessing topology-dependent energy transfer dynamics in upconversion nanoparticles for advancing low-power super-resolution applications.
文摘With the consideration of slip deformation mechanism and various slip systems of body centered cubic （BCC） metals, Taylor-type and finite element polycrystal models were embedded into the commercial finite element code ABAQUS to realize crystal plasticity finite element modeling, based on the rate dependent crystal constitutive equations. Initial orientations measured by electron backscatter diffraction （EBSD） were directly input into the crystal plasticity finite element model to simulate the develop- ment of rolling texture of interstitial-free steel （IF steel） at various reductions. The modeled results show a good agreement with the experimental results. With increasing reduction, the predicted and experimental rolling textures tend to sharper, and the results simulated by the Taylor-type model are stronger than those simulated by finite element model.＇Conclusions are obtained that rolling textures calculated with 48 { 110} 〈 111 〉＋ { 112 } 〈 111〉＋ { 123 } 〈 111 〉 slip systems are more approximate to EBSD results.
基金financial support of the National Natural Science Foundation of China (Grant Nos.51979266,51879258 and 51991392)。
文摘Tamusu mudstone formation, located in the Alxa area in western Inner Mongolia, is considered a potential host formation for high-level radioactive waste(HLW) underground disposal in China. In this study, complementary analyses with X-ray diffraction(XRD), field emission scanning electron microscopy(FE-SEM), mercury intrusion porosimetry(MIP), and N_(2) physisorption isotherm were conducted on the Tamusu mudstone to characterize its physical characteristics and microstructural features, such as mineral compositions and pore structure. Several minerals, including carbonates, feldspar, clays and analcime, were identified in Tamusu mudstone by XRD. Images from FE-SEM show that pores in the Tamusu mudstone were dominantly on nanometer scale and generally located within their mineral matrix or at the interface with non-porous minerals. The combination of the MIP and N_2 physisorption curves indicated that the Tamusu mudstone has diverse pore sizes, a porosity varying from 2.34% to 2.84%, and a total pore volume in the range of 0.0065—0.0222 cm^(3)/g with the average pore diameter ranging from 9.6 nm to 19.23 nm. The specific surface area measured by MIP(2.572—5.861 m^(2)/g) was generally higher than that by N_(2) physisorption(1.29—3.04 m^(2)/g), due to the pore network effect, pore shape(e.g. ink-bottle shape), or technique limits. The results related to pore information can be applied as an input in the future to model single-or multi-phase fluid flow and the transport of radionuclides in porous geomedium by migration and diffusion.
基金This work was partly supported by the National Key Basic Research Program of China (973 project)under Grant No.2015CB352006the National Natural Science Foundation of China under Grant Nos.61335011 and 61405035Program for Changjiang Scholars and Innovative Research Team in University under Grant No.IRT 15R10.
文摘Far-¯eld°uorescence microscopy has made great progress in the spatial resolution,limited by light diffraction,since the super-resolution imaging technology appeared.And stimulated emission depletion(STED)microscopy and structured illumination microscopy(SIM)can be grouped into one class of the super-resolution imaging technology,which use pattern illumination strategy to circumvent the di®raction limit.We simulated the images of the beads of SIM imaging,the intensity distribution of STED excitation light and depletion light in order to observe effects of the polarized light on imaging quality.Compared to¯xed linear polarization,circularly polarized light is more suitable for SIM on reconstructed image.And right-handed circular polarization(CP)light is more appropriate for both the excitation and depletion light in STED system.Therefore the right-handed CP light would be the best candidate when the SIM and STED are combined into one microscope.Good understanding of the polarization will provide a reference for the patterned illumination experiment to achieve better resolution and better image quality.
基金Project supported by the National Key Research and Development Program of China(2022YFE0122700)in part by National Natural Science Foundation of China(62371241,62350610268,61971230)in part by the Jiangsu Distinguished Professor Program(R2022T48)。
文摘Excellent magnetic properties in ferrites are required for high-frequency applications and for wastewater treatment. Thus, the present study shows the comparison of magnetic and structural properties of Nd and Sm substituted Ni-Zn-Bi ferrites with the series Ni_(0.5)Zn_(0.5)Bi_(0.04)Nd_(x)Fe_(1.96-x)O_4(with step size 0.002)and Ni_(0.5)Zn_(0.5)Bi_(0.04)Sm_(x)Fe_(1.96-x)O_4(with step size 0.02) prepared using citrate precursor method. The impact of the substitution of rare earth ions(Nd and Sm) on magnetic properties of the synthesized samples is observed using a vibrating sample magnetometer(VSM). The saturation magnetization values enhance considerably from 52 to 58 emu/g for Nd^(3+)ions and 39 to 57 emu/g for Sm^(3+) ions, thus, making these materials magnetically hard. Further, the higher value of coercivity is also observed ranging from133 to 167 Oe for Nd^(3+)ions and 81 to 155 Oe for Sm^(3+) ions. The shape of hysteresis loops indicates a super paramagnetic and ferromagnetic behavior in the obtained samples. The squareness ratio value is<0.5, suggesting the uniaxial anisotropy of particles and hence, these ferrites are suitable for microwaveabsorbing and in permanent magnetic materials. The X-ray diffraction(XRD) pattern shows the formation of pure cubic crystallites, where, lattice parameters range from 0.840 to 0.839 nm and from 0.838to 0.839 nm for Nd^(3+)and Sm^(3+) ions substitution, respectively. The crystallite size ranges between 28.63to 29.89 nm and 18.33 to 26.23 nm, for substitution of Nd^(3+)and Sm^(3+) ions, respectively. Field emission scanning electron microscopy(FESEM) shows the formation of homogeneous grains, whereas, energy dispersive spectrometer(EDS) counts describe the purity of the samples. The Sm concentration x = 0.10has the maximum surface area with value of 42.6 m^(2)/g which proves to be having good data storage application due to high surface area. The zero-field cooled(ZFC) and field cooled(FC) data show that Nddoped Ni-Zn-Bi nanoferrites show superparamagnetic behaviour in the room temperature range which makes them suitable for practical applications.
基金supported by National Institutes of Health Grants R21-AG048506,P01-AG000538 and RO1-AG34667(to CWC)UC MEXUS-CONACYT Grant CN-16-170(to GAP and CWC)
文摘Synapses are essential units for the flow of information in the brain.Over the last 70 years,synapses have been widely studied in multiple animal models including worms,fruit flies,and rodents.In comparison,the study of human synapses has evolved significantly slower,mainly because of technical limitations.However,three novel methods allowing the analysis of molecular,morphological,and functional properties of human synapses may expand our knowledge of the human brain.Here,we briefly describe these methods,and evaluate how the information provided by each unique approach may contribute to the functional and anatomical analysis of the synaptic component of human brain circuitries.In particular,using tissue from cryopreserved human brains,synaptic plasticity can be studied in isolated synaptosomes by fluorescence analysis of single-synapse long-term potentiation（FASS-LTP）,and subpopulations of synapses can be thoroughly assessed in the ribbons of brain tissue by array tomography（AT）.Currently,it is also possible to quantify synaptic density in the living human brain by positron emission tomography（PET）,using a novel synaptic radio-ligand.Overall,data provided by FASS-LTP,AT,and PET may significantly contribute to the global understanding of synaptic structure and function in both healthy and diseased human brains,thus directly impacting translational research.
基金supported by the National Natural Science Foundation of China(61378062,21227804,21390414,61475181)the National Basic ResearchProgram of China(2012CB825805)the Shanghai Municipal Commission for Science and Technology(14ZR1448000)
文摘The significant role of telomeres in cells has attracted much attention since they were discovered.Fluorescence imaging is an effective method to study subcellular structures like telomeres.However,the diffraction limit of traditional optical microscope hampers further investigation on them.Recent progress on superresolution fluorescence microscopy has broken this limit.In this work,we used stimulated emission depletion(STED) microscope to observe fluorescence-labeled telomeres in interphase cell nuclei.The results showed that the size of fluorescent puncta representing telomeres under the STED microscope was much smaller than that under the confocal microscope.Two adjacent telomeres were clearly separated via STED imaging,which could hardly be discriminated by confocal microscopy due to the diffraction limit.We conclude that STED microscope is a more powerful tool that enable us to obtain detailed information about telomeres.
基金support from the Public Welfare Fund(YXD23H0301)from the Natural Science Foundation of Zhejiangthe National Natural Science Foundation of China(22374134,22004123,and the Excellent Young Scientists Fund)+5 种基金the National Key Scientific Program of China(2022YFA1304500 and 2022YFC3401003)the Zhejiang Leading Innovation and Entrepreneurship Team(2022R01006)the“Pioneer”and“Leading Goose”R&D Program of Zhejiang(2023SDYXS0001)the Hangzhou Institute of Medicine,the Chinese Academy of Sciences(2024ZZBS04)the KEY R&D Program of Zhejiang(2023C03058)the Natural Science Foundation of Shandong Province(ZR2022YQ12).
文摘Stimulated emission depletion(STED)microscopy requires fluorescent probes to exhibit high brightness,good photostability,a sensitive optical depletion response,and narrow spectral features.There are great interests in using polymer dots(Pdots)for STED imaging due to their exceptional brightness and photobleaching resistance.However,the conven-tional Pdots either suffer from broad spectra or an unsatisfactory STED response.Herein,we developed a general method for obtaining Pdots with desirable optical properties for STED microscopy.Speciically,boron.dipyrromethene(BODIpY)chromophores were grafted on to a polystyrene backbone to obtain polymers with narrow spectral profiles.The grafting ratio was precisely controlled to minimize aggregation-induced quenching.Conjugating BODIpYs to side chains reduced interactions between the chromophores,resulting in a long excited state lifetime,which is critical for obtaining complete fluorescence depletion.Using this strategy,we synthesized three-color Pdots with narrow spectra features.Compared to directly encapsulating BODIpYs into nanoparticles,our strategy achieved 2-10 times higher single-particle brightness.We used Pdots for single-particle,cellular,and tissular STED imaging.The Pdots showed high spatial resolutions and could clearly resolve subdiffraction-limit structures in cells and tissue sections,indicating great application potential in in vitro diagnostics and biomedical imaging applications.
基金We are grateful to DST and UGC(PURSE program),Government of India,for the financial assistance.
文摘Highly crystallized mullite has been achieved at temperatures of 1100℃and 1400℃by sol-gel technique in presence of titanium and strontium ions of different concentrations:G_(0)=0 M,G_(1)=0.002 M,G_(2)=0.01 M,G_(3)=0.02 M,G_(4)=0.1 M,G_(5)=0.2 M and G6=0.5 M.X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),field emission scanning electron microscopy(FESEM),LCR meter characterized the samples.Mullite formation was found to depend on the concentration of the ions.The dielectric properties(dielectric constant,loss tangent and AC conductivity)of the composites have been measured,and their variation with increasing frequency and concentration of the doped metals was investigated.All the experiments were performed at room temperature.The composites showed maximum dielectric constants of 24.42 and 37.6 at 1400℃of 0.01 M concentration for titanium and strontium ions at 2 MHz,respectively.Due to the perfect nature of the doped mullite,it can be used for the fabrication of high charge storing capacitors and also as ceramic capacitors in the pico range.
基金supported by funds from the National Natural Science Foundation of China(32030056 and 32100962)the Tsinghua University Spring Breeze Fund(20201080572)+4 种基金the National Science Fund for Distinguished Young Scholars(3210110055)the China Postdoctoral Science Foundation(2020TQ0178,2020M680519,and 2020M680521)the Guangdong Basic and Applied Basic Research Foundation(2023B1515020039)the Shenzhen Science and Technology Program(RCYX20221008092904016)the Shenzhen University 2035 Program for Excellent Research(2022C012).
文摘Mammalian mitochondrial electron transport chain complexes are the most important and complicated protein machinery in mitochondria.Although this system has been studied for more than a century,its composition and molecular mechanism are still largely unknown.Here we report the high-resolution cryo-electron microscopy(Cryo-EM)structures of porcine respiratory chain megacomplex-Ⅰ_(2)Ⅲ_(2)Ⅳ_(2)(MCⅠ_(2)Ⅲ_(2)Ⅳ_(2))in five different conformations,including State 1,State 2,Mid 1,Mid 2,and Mid 3.High-resolution Cryo-EM imaging,combined with super-resolution gated stimulated emission depletion microscopy(gSTED),strongly supports the formation of MCⅠ_(2)Ⅲ_(2)Ⅳ_(2)in live cells.Each MCⅠ_(2)Ⅲ_(2)Ⅳ_(2)structure contains 141 subunits(70 different kinds of peptides,2.9 MDa)in total with 240 transmembrane helices.The mutual influence among CⅠ,CⅢ,and CⅣshown in the MCⅠ_(2)Ⅲ_(2)Ⅳ_(2)structure suggests this megacomplex could act as an integral unit in electron transfer and proton pumping.The conformational changes from different states suggest a plausible regulatory mechanism for the MCⅠ_(2)Ⅲ_(2)Ⅳ_(2)activation/deactivation process.
