Background:Glioblastoma(GBM)is a highly aggressive brain tumor characterized by aberrant angiogenesis and an immunosuppressive microenvironment.Pericytes are aberrantly recruited but their spatiotemporal roles and mol...Background:Glioblastoma(GBM)is a highly aggressive brain tumor characterized by aberrant angiogenesis and an immunosuppressive microenvironment.Pericytes are aberrantly recruited but their spatiotemporal roles and molecular changes remain unclear.This study investigated platelet-derived growth factor receptor beta-positive(Pdgfrb+)pericyte dynamics and reprogramming in GBM vasculature.Methods:We generated GL261-Luc and GL261-CFP glioblastoma cells via lentiviral transduction and established two transgenic models.(1)For pericyte labeling,Ai14 reporter mice was crossed with PDGFRβ-P2A-CreERT2mice for td Tomato-specific lineage tracing(PT mice).(2)For conditional ablation,we generated inducible Pdgfrb-expressing cell ablation models(PT mice was crossed with ROSA-DTA mice).An intravital imaging platform(FITC-dextran/CFP/td Tomato+two-photon microscopy)tracked pericytes,vessels,and tumor cells,while FACSsorted Pdgfrb+cells from GBM and normal brain were analyzed by LC-MS/MS proteomics.Results:Cre-mediated ablation of Pdgfrb-expressing cells revealed stage-dependent effects on GBM growth:early ablation inhibited progression while late ablation promoted it.Pericytes undergo dual spatial reorganization in GBM:regional enrichment with pre-sprouting accumulation at the tumor-brain interface,and focal positioning with preferential localization at vascular branch points.Concurrently,GBM vasculature displayed simplified branching,dilation,and pericyte remodeling(shorter processes,higher density).Proteomics revealed 1426 altered proteins,with upregulated proliferation pathways(e.g.,matrix metallopeptidase 14[Mmp14],lysyl oxidase like 2[Loxl2])and downregulated homeostasis functions(e.g.,transforming growth factor beta 1[Tgfb1]),validated by scRNA-seq in human GBM.Conclusions:This study demonstrates that during early GBM progression,pericytes actively drive tumor angiogenesis through molecular reprogramming toward proliferative and pro-angiogenic phenotypes,with the integrated imaging-proteomics framework revealing potential therapeutic targets for disrupting pericyte-mediated vascular remodeling.展开更多
Adriamycin(doxorubicin),a common cancer chemotherapeutic drug,can be used to induce a model of chronic progressive glomerular disease in rodents.In our studies,we evahuated renal changes in a rat model after Adriamydi...Adriamycin(doxorubicin),a common cancer chemotherapeutic drug,can be used to induce a model of chronic progressive glomerular disease in rodents.In our studies,we evahuated renal changes in a rat model after Adriamydin injection using two photon microscopy(TPM),optical coherence tomography(OCT)and Doppler OCT(DOCT).Taking advantage of deep penetra-tion and fast scanning speed for three dimensional(3D)label-free imaging,OCT/DOCT system was able to reveal glomerular and tubular pathology noninvasively and in real time.By imaging renal pathology following the infusion of fAuorophore-labeled dextrans of different molecular weights,TPM can provide direct views of glomerular and tubular flow dynamics with the onset and progression of renal disease.Specifically,glomerular permeability and filtration,proximal and distal tubular flow dynamics can be revealed.6-8 weeks after injection of Adriamycin,TPM and OCT/DOCT imaging revealed glomerular sclerosis,compromised flow across the glomerular wall,tubular atrophy,tubular dilation,and variable intra-tubular flow dynamics.Our results indicate that TPM and OCT/DOCT provide real-time imaging of renal pathology in vivo that has not been previously available using conventional microscopic procedures.展开更多
Two-photon microscopy normally suffers from the scattering of the tissue in biological imaging.Multidither coberent optical adaptive technique(COAT)can correct the scattered wavefront in parallel.However,the determina...Two-photon microscopy normally suffers from the scattering of the tissue in biological imaging.Multidither coberent optical adaptive technique(COAT)can correct the scattered wavefront in parallel.However,the determination of the corrective phases may not be completely accurate using conventional method,which undermines the performance of this technique.In this paper,we theoretically demonstrate a method that can obtain more accurate corrective phases by determining the phase values from the square root of the fuorescence signal.A numnerical simulation model is established to study the performance of adaptive optics in two-photon micros-copy by combining scalar diffraction theory with vector diffraction theory.The results show that the distortion of the wavefront can be corrected more thoroughly with our method in two-photon imaging.In our simulation,with the scattering from a 450-mn-thick mouse brain tissue,excitation focal spots with higher peak-to background ratio(PBR)and images with higher contrast can be obtained.Hence,further enhancement of the multidither COAT correction performance in two-photon imaging can be expected.展开更多
Visible femtosecond lasers,especially within the deep-red wavelengths,are critical for applications such as bioimaging,biomedicine,and material processing.Traditional visible ultrafast lasers,such as Ti:sapphire laser...Visible femtosecond lasers,especially within the deep-red wavelengths,are critical for applications such as bioimaging,biomedicine,and material processing.Traditional visible ultrafast lasers,such as Ti:sapphire lasers or nonlinear frequency-converted lasers,face limitations in size,cost,stability,and efficiency.Here,we demonstrate a Pr^(3+)-doped mode-locked fiber laser(MLFL),directly generating sub-100-fs pulses at deep-red wavelength.This approach involves theoretical optimization and experimental validation using a ring cavity with Pr^(3+):ZBLAN fiber and nonlinear polarization rotation.The resulting ultrafast laser operates at 716.6 nm,delivering pulses with an~13-nm bandwidth and 83-fs duration at an~73.7-MHz repetition rate.To showcase the feasibility of this 717-nm MLFL for practical applications,twophoton microscopy is demonstrated with outstanding and unique performance regarding the simultaneous multicolor excitation of blue,green,and red dyes,enhanced resolution by 33%,and approximately four times higher excitation efficiency,compared with the conventional excitation wavelength at~1064 nm.These advantages confirm its versatility and reliability in biophotonic imaging.Our findings pave the way for compact,efficient sub-100-fs visible fiber lasers for multicolor bioimaging applications.展开更多
Light penetration depth in biological tissue is limited by tissue scattering.Correcting scattering becomes particularly challenging in scenarios with limited photon availability and when access to the transmission sid...Light penetration depth in biological tissue is limited by tissue scattering.Correcting scattering becomes particularly challenging in scenarios with limited photon availability and when access to the transmission side of the scattering tissue is not possible.Here,we introduce,to our knowledge,a new two-photon microscopy system with Fourier-domain intensity coupling for scattering correction(2P-FOCUS).2P-FOCUS corrects scattering by intensity modulation in the Fourier domain,leveraging the nonlinearity of multiple-beam interference and twophoton excitation,eliminating the need for a guide star,iterative optimization,or measuring transmission or reflection matrices.2P-FOCUS uses random patterns to probe scattering properties,combined with a single-shot algorithm to rapidly generate the correction mask.2P-FOCUS can also correct scattering beyond the limitation of the memory effect by automatically customizing correction masks for each subregion in a large field-of-view.We provide several proof-of-principle demonstrations here,including focusing and imaging through a bone sample,and imaging neurons and cerebral blood vessels in the mouse brain ex vivo.2P-FOCUS significantly enhances two-photon fluorescence signals by several tens of folds compared to cases without scattering correction at the same excitation power.2P-FOCUS can also correct tissue scattering over a 230μm×230μm×510μm volume,which is beyond the memory effect range.2P-FOCUS is able to measure,calculate,and correct scattering within a few seconds,effectively delivering more light deep into the scattering tissue.2P-FOCUS could be broadly adopted for deep tissue imaging owing to its powerful combination of effectiveness,speed,and cost.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
Objective:Verrucous epidermal nevus(VEN),seborrheic keratosis(SK),verruca plana(VP),verruca vulgaris(VV),and nevus sebaceous(NS)are common verrucous proliferative skin diseases with similar clinical appearances,often ...Objective:Verrucous epidermal nevus(VEN),seborrheic keratosis(SK),verruca plana(VP),verruca vulgaris(VV),and nevus sebaceous(NS)are common verrucous proliferative skin diseases with similar clinical appearances,often posing diagnostic challenges.Dermoscopy and reflectance confocal microscopy(RCM)can aid in their differentiation,yet their specific features under these tools have not been systematically described.This study aims to summarize and analyze the dermoscopic and RCM features of VEN,SK,VP,VV,and NS.Methods:A total of 121 patients with histopathologically confirmed verrucous proliferative skin diseases were enrolled.Dermoscopy and RCM imaging was used to observe and analyze the microscopic features of these conditions.Results:Under dermoscopy,the 5 diseases displayed distinct characteristics:VEN typically showed gyriform structures;SK was characterized by gyriform structures,comedo-like openings,and milia-like cysts;VP and VV featured dotted vessels and frogspawn-like structures;NS presented as brownish-yellow globules.RCM revealed shared features such as hyperkeratosis and acanthosis across all 5 diseases.Specific features included gyriform structures and elongated rete ridges in VEN;pseudocysts and gyriform structures in SK;evenly distributed ring-like structures in VP;vacuolated cells and papillomatous proliferation in VV;and frogspawn-like structures in NS.Conclusion:These 5 verrucous proliferative skin conditions exhibit distinguishable features under both dermoscopy and RCM.The combination of these 2 noninvasive imaging modalities holds significant clinical value for the differential diagnosis of verrucous proliferative skin diseases.展开更多
Full-color imaging is essential in digital pathology for accurate tissue analysis.Utilizing advanced optical modulation and phase retrieval algorithms,Fourier ptychographic microscopy(FPM)offers a powerful solution fo...Full-color imaging is essential in digital pathology for accurate tissue analysis.Utilizing advanced optical modulation and phase retrieval algorithms,Fourier ptychographic microscopy(FPM)offers a powerful solution for high-throughput digital pathology,combining high resolution,large field of view,and extended depth of field(DOF).However,the full-color capabilities of FPM are hindered by coherent color artifacts and reduced computational efficiency,which significantly limits its practical applications.Color-transferbased FPM(CFPM)has emerged as a potential solution,theoretically reducing both acquisition and reconstruction threefold time.Yet,existing methods fall short of achieving the desired reconstruction speed and colorization quality.In this study,we report a generalized dual-color-space constrained model for FPM colorization.This model provides a mathematical framework for model-based FPM colorization,enabling a closed-form solution without the need for redundant iterative calculations.Our approach,termed generalized CFPM(gCFPM),achieves colorization within seconds for megapixel-scale images,delivering superior colorization quality in terms of both colorfulness and sharpness,along with an extended DOF.Both simulations and experiments demonstrate that gCFPM surpasses state-of-the-art methods across all evaluated criteria.Our work offers a robust and comprehensive workflow for high-throughput full-color pathological imaging using FPM platforms,laying a solid foundation for future advancements in methodology and engineering.展开更多
Alzheimer's disease(AD)is a neurodegenerative disease characterized by a progressive decline in cognitive functions.Given that AD undermines the quality of life for millions and has an extended asymptomatic period...Alzheimer's disease(AD)is a neurodegenerative disease characterized by a progressive decline in cognitive functions.Given that AD undermines the quality of life for millions and has an extended asymptomatic period,exploring the full AD pathogenesis and seeking the optimal therapeutic solution have become critical and imperative.This allows researchers to intervene,delay,and potentially prevent AD progression.Several clinical imaging methods are utilized routinely to diagnose and monitor AD,such as magnetic resonance imaging(MRI),functional magnetic resonance imaging(fMRI),positron emission tomography(PET),and single photon emission computed tomography(SPECT).Nevertheless,due to their intrinsic drawbacks and restrictions,such as radiation concerns,high cost,long acquisition time,and low spatial resolution,their applications in AD research are limited,especially at the cellular and molecular levels.In contrast,optical microscopic imaging methods overcome these limitations,offering researchers a variety of approaches with distinct advantages to explore AD pathology on diverse models.In this review,we provide a comprehensive overview of commonly utilized optical microscopic imaging techniques in AD research and introduce their contributions to image amyloid beta(Aβ)species.These techniques include fluorescence microscopy(FM),confocal microscopy(CM),two-photon fluorescence microscopy(TPFM),super-resolution microscopy(SRM),expansion microscopy(ExM),and light-sheet fluorescence microscopy(LSFM).In addition,we introduce some related topics,such as the development of near-infrared(NIR)Aβprobes,the Aβplaque hypothesis,and Aβoligomer hypothesis,and the roles of microglia and astrocytes in AD progression.We believe optical microscopic imaging methods continue to play an indispensable role in deciphering the full pathogenesis of AD and advancing therapeutic strategies.展开更多
The characteristics of nonmetallic inclusions formed during steel production have a significant influence on steel performance.In this paper,studies on inclusions using confocal scanning laser microscopy(CSLM)are revi...The characteristics of nonmetallic inclusions formed during steel production have a significant influence on steel performance.In this paper,studies on inclusions using confocal scanning laser microscopy(CSLM)are reviewed and summarized,particularly the col-lision of various inclusions,dissolution of inclusions in liquid slag,and reactions between inclusions and steel.Solid inclusions exhibited a high collision tendency,whereas pure liquid inclusions exhibited minimal collisions because of the small attraction force induced by their<90°contact angle with molten steel.The collision of complex inclusions in molten steel was not included in the scope of this study and should be evaluated in future studies.Higher CaO/Al_(2)O_(3)and CaO/SiO_(2)ratios in liquid slag promoted the dissolution of Al_(2)O_(3)-based in-clusions.The formation of solid phases in the slag should be prevented to improve dissolution of inclusions.To accurately simulate the dissolution of inclusions in liquid slag,in-situ observation of the dissolution of inclusions at the steel-slag interface is necessary.Using a combination of CSLM and scanning electron microscopy-energy dispersive spectroscopy,the composition and morphological evolution of the inclusions during their modification by the dissolved elements in steel were observed and analyzed.Although the in-situ observa-tion of MnS and TiN precipitations has been widely studied,the in-situ observation of the evolution of oxide inclusions in steel during so-lidification and heating processes has rarely been reported.The effects of temperature,heating and cooling rates,and inclusion character-istics on the formation of acicular ferrites(AFs)have been widely studied.At a cooling rate of 3-5 K/s,the order of AF growth rate in-duced by different inclusions,as reported in literature,is Ti-O<Ti-Ca-Zr-Al-O<Mg-O<Ti-Zr-Al-O<Mn-Ti-Al-O<Ti-Al-O<Zr-Ti-Al-O.Further comprehensive experiments are required to investigate the quantitative relationship between the formation of AFs and inclusions.展开更多
High-resolution transmission electron microscopy(HRTEM)promises rapid atomic-scale dynamic structure imaging.Yet,the precision limitations of aberration parameters and the challenge of eliminating aberrations in Cs-co...High-resolution transmission electron microscopy(HRTEM)promises rapid atomic-scale dynamic structure imaging.Yet,the precision limitations of aberration parameters and the challenge of eliminating aberrations in Cs-corrected transmission electron microscopy constrain resolution.A machine learning algorithm is developed to determine the aberration parameters with higher precision from small,lattice-periodic crystal images.The proposed algorithm is then validated with simulated HRTEM images of graphene and applied to the experimental images of a molybdenum disulfide(MoS_(2))monolayer with 25 variables(14 aberrations)resolved in wide ranges.Using these measured parameters,the phases of the exit-wave functions are reconstructed for each image in a focal series of MoS_(2)monolayers.The images were acquired due to the unexpected movement of the specimen holder.Four-dimensional data extraction reveals time-varying atomic structures and ripple.In particular,the atomic evolution of the sulfur-vacancy point and line defects,as well as the edge structure near the amorphous,is visualized as the resolution has been improved from about 1.75?to 0.9 A.This method can help salvage important transmission electron microscope images and is beneficial for the images obtained from electron microscopes with average stability.展开更多
To investigate the mechanisms underlying the onset and progression of ischemic stroke,some methods have been proposed that can simultaneously monitor and create embolisms in the animal cerebral cortex.However,these me...To investigate the mechanisms underlying the onset and progression of ischemic stroke,some methods have been proposed that can simultaneously monitor and create embolisms in the animal cerebral cortex.However,these methods often require complex systems and the effect of age on cerebral embolism has not been adequately studied,although ischemic stroke is strongly age-related.In this study,we propose an optical-resolution photoacoustic microscopy-based visualized photothrombosis methodology to create and monitor ischemic stroke in mice simultaneously using a 532 nm pulsed laser.We observed the molding process in mice of different ages and presented age-dependent vascular embolism differentiation.Moreover,we integrated optical coherence tomography angiography to investigate age-associated trends in cerebrovascular variability following a stroke.Our imaging data and quantitative analyses underscore the differential cerebrovascular responses to stroke in mice of different ages,thereby highlighting the technique's potential for evaluating cerebrovascular health and unraveling age-related mechanisms involved in ischemic strokes.展开更多
Enamel demineralization often occurs in the early stage of dental caries.Studying the microscopic mechanism of enamel demineralization is essential to prevent and treat dental caries.Terahertz(THz)technolo⁃gy,especial...Enamel demineralization often occurs in the early stage of dental caries.Studying the microscopic mechanism of enamel demineralization is essential to prevent and treat dental caries.Terahertz(THz)technolo⁃gy,especially continuous wave(CW)THz near-field scanning microscopy(THz-SNOM)with its nanoscale reso⁃lution,can be promising in biomedical imaging.In addition,compared with traditional THz time-domain spec⁃troscopy(TDS),portable solid-state source as the emission has higher power and SNR,lower cost,and can ob⁃tain more precise imaging.In this study,we employ CW THz-SNOM to further break the resolution limitations of conventional THz imaging techniques and successfully achieve the near-field imaging of demineralized enamel at the nanoscale.We keenly observe that the near-field signal of the enamel significantly lowers as demineralization deepens,mainly due to the decrease in permittivity.This new approach offers valuable insights into the micro⁃scopic processes of enamel demineralization,laying the foundation for further research and treatment.展开更多
Two-photon dissociation of BeH^(+)ions is studied by detecting the fluorescence changes of Be^(+)-BeH^(+)bi-component Coulomb crystal in a linear Paul trap.BeH^(+)ions generated by an exothermic reaction between elect...Two-photon dissociation of BeH^(+)ions is studied by detecting the fluorescence changes of Be^(+)-BeH^(+)bi-component Coulomb crystal in a linear Paul trap.BeH^(+)ions generated by an exothermic reaction between electronically excited Be^(+)ions and residual H_(2) in the vacuum chamber are photon-dissociated with two photons scanning over the range of 201 nm to 208 nm.Our experiment provides a novel method to maintain the number of Be^(+)ions stable in a Coulomb crystal with a middle ultraviolet band dissociation laser.This two-photon dissociation method extends the wavelength range of the dissociation laser for BeH^(+)compared to the one-photon dissociation,and the method can be utilized to all alkaline earth atomic ions which require suppression of the reaction with residual H_(2) gas in vacuum.展开更多
Stochastic optical reconstruction microscopy(STORM),as a typical technique of single-molecule localization microscopy(SMLM),has overcome the diffraction limit by randomly switching fluorophores between fluorescent and...Stochastic optical reconstruction microscopy(STORM),as a typical technique of single-molecule localization microscopy(SMLM),has overcome the diffraction limit by randomly switching fluorophores between fluorescent and dark states,allowing for the precise localization of isolated emission patterns and the super-resolution reconstruction from millions of localized positions of single fluorophores.A critical factor influencing localization precision is the photo-switching behavior of fluorophores,which is affected by the imaging buffer.The imaging buffer typically comprises oxygen scavengers,photo-switching reagents,and refractive index regulators.Oxygen scavengers help prevent photobleaching,photo-switching reagents assist in facilitating the conversion of fluorophores,and refractive index regulators are used to adjust the refractive index of the solution.The synergistic interaction of these components promotes stable blinking of fluorophores,reduces irreversible photobleaching,and thereby ensures high-quality super-resolution imaging.This review provides a comprehensive overview of the essential compositions and functionalities of imaging buffers used in STORM,serving as a valuable resource for researchers seeking to select appropriate imaging buffers for their experiments.展开更多
Hypochlorous acid(HClO)is a critical biomolecule in living organisms,playing an essential role in numerous physiological or pathological processes.Abnormal levels of HClO in the body may lead to a series of diseases,f...Hypochlorous acid(HClO)is a critical biomolecule in living organisms,playing an essential role in numerous physiological or pathological processes.Abnormal levels of HClO in the body may lead to a series of diseases,for instance,inflammation and cancer.Thus,accurate measurement of HClO levels should be more beneficial for understanding its role in diseases and gaining a deeper insight into the pathogenesis of diseases.In this work,we designed a near-infrared two-photon fluorescent probe(HDM-Cl-HClO)for detecting fluctuations in HClO levels in inflammatory and tumor-bearing mice.Notably,the probe can respond to HClO within 5 s and trigger a brilliant red fluorescence at 660 nm.It exhibits high specificity and sensitivity for HClO.The superior spectral capability of the probe has enabled the detection of HClO levels in cells and zebrafish,as well as achieved the detection of HClO in inflammatory and tumor mice.This work not only provides a novel strategy and tool for HClO imaging in living systems,but also holds great potential for the diagnosis of inflammation and cancer.展开更多
Recently,charged solitons have been found in a two-dimensional CoCl_(2)/HOPG system,whose microscopic nature remains to be elusive.In this work,we investigate the charged solitons in monolayer CoCl_(2) using scanning ...Recently,charged solitons have been found in a two-dimensional CoCl_(2)/HOPG system,whose microscopic nature remains to be elusive.In this work,we investigate the charged solitons in monolayer CoCl_(2) using scanning tunneling microscopy(STM)and atomic force microscopy(AFM).Moreover,we study the electrical properties of the charged solitons at zero electric field by measuring local contact potential difference(LCPD)via Kelvin probe force microscopy(KPFM)using the Δf(V)method.The compensation voltage corresponding to the vertex of the parabola is obtained by fitting the quadratic relationship between Δf and sample bias.The results show that,without an external electric field,the solitons behave as negatively charged entities.Meanwhile,the LCPD mapping characterizes the spatial distribution of the potential at the charged solitons,which agrees well with those obtained from STM band bending measurements.展开更多
Four benzocoumarin-based two-photon fluorescent probes(BH1-BH4)are proposed for ra-tiometric detection of hypochlorous acid(HClO)and their two-photon sensing perfor-mance are evaluated by means of time-dependent densi...Four benzocoumarin-based two-photon fluorescent probes(BH1-BH4)are proposed for ra-tiometric detection of hypochlorous acid(HClO)and their two-photon sensing perfor-mance are evaluated by means of time-dependent density func-tional theory and quadratic re-sponse theory.The effects of benzene-fused position on Stokes shift,fluorescence quantum yield and two-photon absorption are discussed comprehensively.The results show that fusing a benzene ring in coumarin can enhance Stokes shift efficiently.The benzene-fused position has important effects on these photophysical properties.The benzo[g]coumarins(BH1)and benzo[f]coumarins(BH2)derivatives have larger Stokes shifts in comparison with benzo[h]coumarins(BH3)and dihydrophenazine(BH4)derivatives.The two-photon absorp-tion of benzo[f]coumarins(BH2)derivative is much smaller than those of other benzo-coumarins derivatives.The large Stokes shift and increased two-photon action cross section can be achieved simultaneously in the dihydrophenazine(BH4)derivative.Therefore,the de-signed BH4 is expected to have superior performance for the ratiometric detection of HClO.To explore the reasons behind these effects,the intramolecular charge transfer degrees are il-lustrated quantitatively by plotting the hole-electron isosurface map,and the relation be-tween charge transfer and Stokes shift is revealed.A two-state model analysis is employed to understand two-photon absorption ability.Moreover,the fluorescence near-quenching mecha-nism of the product molecules B1 and B3 is explained by analyzing reorganization energy and Huang-Rhys factor,as well as related normal mode.Our research could contribute to the effi-cient design of ratiometric two-photon fluorescent probes with large Stokes shift and signifi-cant two-photon action cross section.展开更多
Optical-resolution photoacoustic microscopy is a novel imaging technique that combines the advantages of optical and ultrasound imaging,enabling high-resolution visualization of biological tissues at the micrometer sc...Optical-resolution photoacoustic microscopy is a novel imaging technique that combines the advantages of optical and ultrasound imaging,enabling high-resolution visualization of biological tissues at the micrometer scale.However,the divergence of the excited Gaussian beam limits the depth-of-field of the system to less than 100μm,which hinders accurate three-dimensional imaging of living tissues and restrictsits applicability in biological research.Therefore,there is an urgent need for an effective method to enhance the depth-of-field without altering the hardware configuration.This paper presents a photoacoustic microscopy depth-of-field extension method and system based on three-dimensional continuity and sparsity deconvolution.This method utilizes a depth-varying point spread function and incorporates continuity and sparsity con-straints into the deconvolution process to mitigate the effect of background noise,enhancing the stability and accuracy of the depth-of-field extension.Experimental results using tungsten wire phantoms suggest that the depth-of-field of system can be extended to 650 pm,which is 7.2 times greater than conventional system,while improving the resolution of the defocused region by an average factor of 3.5.Furthermore,experiments on zebrafish and nude mouse ears with irregular topologies demonstrate that the proposed method successfully overcomes image blurring and the loss of structural information due to limited depth-of-field.All the results suggest that the system with higher lateral resolution and enhanced depth-of-field has significant potential for a wide range of practical biomedical applications.展开更多
Maintaining the s-polarization state of laser beams is important to achieve high modulation depth in a laser-interference-based super-resolution structured illumination microscope(SR-SIM).However,the imperfect optical...Maintaining the s-polarization state of laser beams is important to achieve high modulation depth in a laser-interference-based super-resolution structured illumination microscope(SR-SIM).However,the imperfect optical components can depolarize the laser beams hence degenerating the modulation depth.Here,we first presented a direct measurement method designed to estimate the modulation depth more precisely by shifting illumination patterns with equal phase steps.This measurement method greatly reduces the dependence of modulation depths on the samples,and then developed a polarization optimization method to achieve high modulation depth at all orientations by actively and quantitatively compensating for the additional phase difference using a combination of waveplate and a liquid crystal variable retarder(LCVR).Experimental results demonstrate that our method can achieve illumination patterns with modulation depth higher than 0.94 at three orientations with only one LCVR voltage,which enables isotropic resolution improvement.展开更多
基金The National Key Research and Development Program of China,Grant/Award Number:2022YFF0710700Nonprofit Central Research Institute Fund of Chinese Academy of Medical Sciences,Grant/Award Number:2023-PT180-01。
文摘Background:Glioblastoma(GBM)is a highly aggressive brain tumor characterized by aberrant angiogenesis and an immunosuppressive microenvironment.Pericytes are aberrantly recruited but their spatiotemporal roles and molecular changes remain unclear.This study investigated platelet-derived growth factor receptor beta-positive(Pdgfrb+)pericyte dynamics and reprogramming in GBM vasculature.Methods:We generated GL261-Luc and GL261-CFP glioblastoma cells via lentiviral transduction and established two transgenic models.(1)For pericyte labeling,Ai14 reporter mice was crossed with PDGFRβ-P2A-CreERT2mice for td Tomato-specific lineage tracing(PT mice).(2)For conditional ablation,we generated inducible Pdgfrb-expressing cell ablation models(PT mice was crossed with ROSA-DTA mice).An intravital imaging platform(FITC-dextran/CFP/td Tomato+two-photon microscopy)tracked pericytes,vessels,and tumor cells,while FACSsorted Pdgfrb+cells from GBM and normal brain were analyzed by LC-MS/MS proteomics.Results:Cre-mediated ablation of Pdgfrb-expressing cells revealed stage-dependent effects on GBM growth:early ablation inhibited progression while late ablation promoted it.Pericytes undergo dual spatial reorganization in GBM:regional enrichment with pre-sprouting accumulation at the tumor-brain interface,and focal positioning with preferential localization at vascular branch points.Concurrently,GBM vasculature displayed simplified branching,dilation,and pericyte remodeling(shorter processes,higher density).Proteomics revealed 1426 altered proteins,with upregulated proliferation pathways(e.g.,matrix metallopeptidase 14[Mmp14],lysyl oxidase like 2[Loxl2])and downregulated homeostasis functions(e.g.,transforming growth factor beta 1[Tgfb1]),validated by scRNA-seq in human GBM.Conclusions:This study demonstrates that during early GBM progression,pericytes actively drive tumor angiogenesis through molecular reprogramming toward proliferative and pro-angiogenic phenotypes,with the integrated imaging-proteomics framework revealing potential therapeutic targets for disrupting pericyte-mediated vascular remodeling.
基金the National Institutes of Health(NIH)Grant Nos.R21AG042700 and R21DK088066。
文摘Adriamycin(doxorubicin),a common cancer chemotherapeutic drug,can be used to induce a model of chronic progressive glomerular disease in rodents.In our studies,we evahuated renal changes in a rat model after Adriamydin injection using two photon microscopy(TPM),optical coherence tomography(OCT)and Doppler OCT(DOCT).Taking advantage of deep penetra-tion and fast scanning speed for three dimensional(3D)label-free imaging,OCT/DOCT system was able to reveal glomerular and tubular pathology noninvasively and in real time.By imaging renal pathology following the infusion of fAuorophore-labeled dextrans of different molecular weights,TPM can provide direct views of glomerular and tubular flow dynamics with the onset and progression of renal disease.Specifically,glomerular permeability and filtration,proximal and distal tubular flow dynamics can be revealed.6-8 weeks after injection of Adriamycin,TPM and OCT/DOCT imaging revealed glomerular sclerosis,compromised flow across the glomerular wall,tubular atrophy,tubular dilation,and variable intra-tubular flow dynamics.Our results indicate that TPM and OCT/DOCT provide real-time imaging of renal pathology in vivo that has not been previously available using conventional microscopic procedures.
基金supported by National Natural Science Foundation of China(Nos.31571110 and 81771877)Natural Science Foundation of Zhejiang Province of China(LZ17F050001)the Fundamental Research Funds for the Central Universities.
文摘Two-photon microscopy normally suffers from the scattering of the tissue in biological imaging.Multidither coberent optical adaptive technique(COAT)can correct the scattered wavefront in parallel.However,the determination of the corrective phases may not be completely accurate using conventional method,which undermines the performance of this technique.In this paper,we theoretically demonstrate a method that can obtain more accurate corrective phases by determining the phase values from the square root of the fuorescence signal.A numnerical simulation model is established to study the performance of adaptive optics in two-photon micros-copy by combining scalar diffraction theory with vector diffraction theory.The results show that the distortion of the wavefront can be corrected more thoroughly with our method in two-photon imaging.In our simulation,with the scattering from a 450-mn-thick mouse brain tissue,excitation focal spots with higher peak-to background ratio(PBR)and images with higher contrast can be obtained.Hence,further enhancement of the multidither COAT correction performance in two-photon imaging can be expected.
基金supported by the National Natural Science Foundation of China(Grant Nos.62235014,62305275,62022069,and 62305274)the Shenzhen Science and Technology Projects(Grant No.JCYJ20210324115813037)the Youth Independent Innovation Science Foundation of the National University of Defense Technology(Grant No.ZK24-20)。
文摘Visible femtosecond lasers,especially within the deep-red wavelengths,are critical for applications such as bioimaging,biomedicine,and material processing.Traditional visible ultrafast lasers,such as Ti:sapphire lasers or nonlinear frequency-converted lasers,face limitations in size,cost,stability,and efficiency.Here,we demonstrate a Pr^(3+)-doped mode-locked fiber laser(MLFL),directly generating sub-100-fs pulses at deep-red wavelength.This approach involves theoretical optimization and experimental validation using a ring cavity with Pr^(3+):ZBLAN fiber and nonlinear polarization rotation.The resulting ultrafast laser operates at 716.6 nm,delivering pulses with an~13-nm bandwidth and 83-fs duration at an~73.7-MHz repetition rate.To showcase the feasibility of this 717-nm MLFL for practical applications,twophoton microscopy is demonstrated with outstanding and unique performance regarding the simultaneous multicolor excitation of blue,green,and red dyes,enhanced resolution by 33%,and approximately four times higher excitation efficiency,compared with the conventional excitation wavelength at~1064 nm.These advantages confirm its versatility and reliability in biophotonic imaging.Our findings pave the way for compact,efficient sub-100-fs visible fiber lasers for multicolor bioimaging applications.
文摘Light penetration depth in biological tissue is limited by tissue scattering.Correcting scattering becomes particularly challenging in scenarios with limited photon availability and when access to the transmission side of the scattering tissue is not possible.Here,we introduce,to our knowledge,a new two-photon microscopy system with Fourier-domain intensity coupling for scattering correction(2P-FOCUS).2P-FOCUS corrects scattering by intensity modulation in the Fourier domain,leveraging the nonlinearity of multiple-beam interference and twophoton excitation,eliminating the need for a guide star,iterative optimization,or measuring transmission or reflection matrices.2P-FOCUS uses random patterns to probe scattering properties,combined with a single-shot algorithm to rapidly generate the correction mask.2P-FOCUS can also correct scattering beyond the limitation of the memory effect by automatically customizing correction masks for each subregion in a large field-of-view.We provide several proof-of-principle demonstrations here,including focusing and imaging through a bone sample,and imaging neurons and cerebral blood vessels in the mouse brain ex vivo.2P-FOCUS significantly enhances two-photon fluorescence signals by several tens of folds compared to cases without scattering correction at the same excitation power.2P-FOCUS can also correct tissue scattering over a 230μm×230μm×510μm volume,which is beyond the memory effect range.2P-FOCUS is able to measure,calculate,and correct scattering within a few seconds,effectively delivering more light deep into the scattering tissue.2P-FOCUS could be broadly adopted for deep tissue imaging owing to its powerful combination of effectiveness,speed,and cost.
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.
基金supported by the Project of Health Committee of Hunan Province(D202304128868),China.
文摘Objective:Verrucous epidermal nevus(VEN),seborrheic keratosis(SK),verruca plana(VP),verruca vulgaris(VV),and nevus sebaceous(NS)are common verrucous proliferative skin diseases with similar clinical appearances,often posing diagnostic challenges.Dermoscopy and reflectance confocal microscopy(RCM)can aid in their differentiation,yet their specific features under these tools have not been systematically described.This study aims to summarize and analyze the dermoscopic and RCM features of VEN,SK,VP,VV,and NS.Methods:A total of 121 patients with histopathologically confirmed verrucous proliferative skin diseases were enrolled.Dermoscopy and RCM imaging was used to observe and analyze the microscopic features of these conditions.Results:Under dermoscopy,the 5 diseases displayed distinct characteristics:VEN typically showed gyriform structures;SK was characterized by gyriform structures,comedo-like openings,and milia-like cysts;VP and VV featured dotted vessels and frogspawn-like structures;NS presented as brownish-yellow globules.RCM revealed shared features such as hyperkeratosis and acanthosis across all 5 diseases.Specific features included gyriform structures and elongated rete ridges in VEN;pseudocysts and gyriform structures in SK;evenly distributed ring-like structures in VP;vacuolated cells and papillomatous proliferation in VV;and frogspawn-like structures in NS.Conclusion:These 5 verrucous proliferative skin conditions exhibit distinguishable features under both dermoscopy and RCM.The combination of these 2 noninvasive imaging modalities holds significant clinical value for the differential diagnosis of verrucous proliferative skin diseases.
基金supported by the National Natural Science Foundation of China(Grant Nos.12104500 and 82430062)the Key Research and Development Projects of Shaanxi Province(Grant No.2023-YBSF-263),the Shenzhen Engineering Research Centre(Grant No.XMHT20230115004)the Shenzhen Science and Technology Innovation Commission(Grant No.KCXFZ20201221173207022).
文摘Full-color imaging is essential in digital pathology for accurate tissue analysis.Utilizing advanced optical modulation and phase retrieval algorithms,Fourier ptychographic microscopy(FPM)offers a powerful solution for high-throughput digital pathology,combining high resolution,large field of view,and extended depth of field(DOF).However,the full-color capabilities of FPM are hindered by coherent color artifacts and reduced computational efficiency,which significantly limits its practical applications.Color-transferbased FPM(CFPM)has emerged as a potential solution,theoretically reducing both acquisition and reconstruction threefold time.Yet,existing methods fall short of achieving the desired reconstruction speed and colorization quality.In this study,we report a generalized dual-color-space constrained model for FPM colorization.This model provides a mathematical framework for model-based FPM colorization,enabling a closed-form solution without the need for redundant iterative calculations.Our approach,termed generalized CFPM(gCFPM),achieves colorization within seconds for megapixel-scale images,delivering superior colorization quality in terms of both colorfulness and sharpness,along with an extended DOF.Both simulations and experiments demonstrate that gCFPM surpasses state-of-the-art methods across all evaluated criteria.Our work offers a robust and comprehensive workflow for high-throughput full-color pathological imaging using FPM platforms,laying a solid foundation for future advancements in methodology and engineering.
基金supported by NIH(R01AG055413),(R01AG085562),(R21AG059134),(R21AG078749),and(S10OD028609)awards(C.R.).NIH Office of the Director,National Institute on Aging.
文摘Alzheimer's disease(AD)is a neurodegenerative disease characterized by a progressive decline in cognitive functions.Given that AD undermines the quality of life for millions and has an extended asymptomatic period,exploring the full AD pathogenesis and seeking the optimal therapeutic solution have become critical and imperative.This allows researchers to intervene,delay,and potentially prevent AD progression.Several clinical imaging methods are utilized routinely to diagnose and monitor AD,such as magnetic resonance imaging(MRI),functional magnetic resonance imaging(fMRI),positron emission tomography(PET),and single photon emission computed tomography(SPECT).Nevertheless,due to their intrinsic drawbacks and restrictions,such as radiation concerns,high cost,long acquisition time,and low spatial resolution,their applications in AD research are limited,especially at the cellular and molecular levels.In contrast,optical microscopic imaging methods overcome these limitations,offering researchers a variety of approaches with distinct advantages to explore AD pathology on diverse models.In this review,we provide a comprehensive overview of commonly utilized optical microscopic imaging techniques in AD research and introduce their contributions to image amyloid beta(Aβ)species.These techniques include fluorescence microscopy(FM),confocal microscopy(CM),two-photon fluorescence microscopy(TPFM),super-resolution microscopy(SRM),expansion microscopy(ExM),and light-sheet fluorescence microscopy(LSFM).In addition,we introduce some related topics,such as the development of near-infrared(NIR)Aβprobes,the Aβplaque hypothesis,and Aβoligomer hypothesis,and the roles of microglia and astrocytes in AD progression.We believe optical microscopic imaging methods continue to play an indispensable role in deciphering the full pathogenesis of AD and advancing therapeutic strategies.
基金supported by the National Key R&D Program(No.2023YFB3709900)the National Nature Science Foundation of China(No.U22A20171)+2 种基金China Baowu Low Carbon Metallurgy Innovation Foundation(No.BWLCF202315)the High Steel Center(HSC)at North China University of TechnologyUniversity of Science and Technology Beijing,China.
文摘The characteristics of nonmetallic inclusions formed during steel production have a significant influence on steel performance.In this paper,studies on inclusions using confocal scanning laser microscopy(CSLM)are reviewed and summarized,particularly the col-lision of various inclusions,dissolution of inclusions in liquid slag,and reactions between inclusions and steel.Solid inclusions exhibited a high collision tendency,whereas pure liquid inclusions exhibited minimal collisions because of the small attraction force induced by their<90°contact angle with molten steel.The collision of complex inclusions in molten steel was not included in the scope of this study and should be evaluated in future studies.Higher CaO/Al_(2)O_(3)and CaO/SiO_(2)ratios in liquid slag promoted the dissolution of Al_(2)O_(3)-based in-clusions.The formation of solid phases in the slag should be prevented to improve dissolution of inclusions.To accurately simulate the dissolution of inclusions in liquid slag,in-situ observation of the dissolution of inclusions at the steel-slag interface is necessary.Using a combination of CSLM and scanning electron microscopy-energy dispersive spectroscopy,the composition and morphological evolution of the inclusions during their modification by the dissolved elements in steel were observed and analyzed.Although the in-situ observa-tion of MnS and TiN precipitations has been widely studied,the in-situ observation of the evolution of oxide inclusions in steel during so-lidification and heating processes has rarely been reported.The effects of temperature,heating and cooling rates,and inclusion character-istics on the formation of acicular ferrites(AFs)have been widely studied.At a cooling rate of 3-5 K/s,the order of AF growth rate in-duced by different inclusions,as reported in literature,is Ti-O<Ti-Ca-Zr-Al-O<Mg-O<Ti-Zr-Al-O<Mn-Ti-Al-O<Ti-Al-O<Zr-Ti-Al-O.Further comprehensive experiments are required to investigate the quantitative relationship between the formation of AFs and inclusions.
基金financial support from the National Natural Science Foundation of China(Grant No.61971201)。
文摘High-resolution transmission electron microscopy(HRTEM)promises rapid atomic-scale dynamic structure imaging.Yet,the precision limitations of aberration parameters and the challenge of eliminating aberrations in Cs-corrected transmission electron microscopy constrain resolution.A machine learning algorithm is developed to determine the aberration parameters with higher precision from small,lattice-periodic crystal images.The proposed algorithm is then validated with simulated HRTEM images of graphene and applied to the experimental images of a molybdenum disulfide(MoS_(2))monolayer with 25 variables(14 aberrations)resolved in wide ranges.Using these measured parameters,the phases of the exit-wave functions are reconstructed for each image in a focal series of MoS_(2)monolayers.The images were acquired due to the unexpected movement of the specimen holder.Four-dimensional data extraction reveals time-varying atomic structures and ripple.In particular,the atomic evolution of the sulfur-vacancy point and line defects,as well as the edge structure near the amorphous,is visualized as the resolution has been improved from about 1.75?to 0.9 A.This method can help salvage important transmission electron microscope images and is beneficial for the images obtained from electron microscopes with average stability.
基金supported by University of Macao,China,Nos.MYRG2022-00054-FHS and MYRG-GRG2023-00038-FHS-UMDF(to ZY)the Macao Science and Technology Development Fund,China,Nos.FDCT0048/2021/AGJ and FDCT0020/2019/AMJ and FDCT 0011/2018/A1(to ZY)Natural Science Foundation of Guangdong Province of China,No.EF017/FHS-YZ/2021/GDSTC(to ZY)。
文摘To investigate the mechanisms underlying the onset and progression of ischemic stroke,some methods have been proposed that can simultaneously monitor and create embolisms in the animal cerebral cortex.However,these methods often require complex systems and the effect of age on cerebral embolism has not been adequately studied,although ischemic stroke is strongly age-related.In this study,we propose an optical-resolution photoacoustic microscopy-based visualized photothrombosis methodology to create and monitor ischemic stroke in mice simultaneously using a 532 nm pulsed laser.We observed the molding process in mice of different ages and presented age-dependent vascular embolism differentiation.Moreover,we integrated optical coherence tomography angiography to investigate age-associated trends in cerebrovascular variability following a stroke.Our imaging data and quantitative analyses underscore the differential cerebrovascular responses to stroke in mice of different ages,thereby highlighting the technique's potential for evaluating cerebrovascular health and unraveling age-related mechanisms involved in ischemic strokes.
基金Supported by the National Natural Science Foundation of China(61988102,62401113,92463308)。
文摘Enamel demineralization often occurs in the early stage of dental caries.Studying the microscopic mechanism of enamel demineralization is essential to prevent and treat dental caries.Terahertz(THz)technolo⁃gy,especially continuous wave(CW)THz near-field scanning microscopy(THz-SNOM)with its nanoscale reso⁃lution,can be promising in biomedical imaging.In addition,compared with traditional THz time-domain spec⁃troscopy(TDS),portable solid-state source as the emission has higher power and SNR,lower cost,and can ob⁃tain more precise imaging.In this study,we employ CW THz-SNOM to further break the resolution limitations of conventional THz imaging techniques and successfully achieve the near-field imaging of demineralized enamel at the nanoscale.We keenly observe that the near-field signal of the enamel significantly lowers as demineralization deepens,mainly due to the decrease in permittivity.This new approach offers valuable insights into the micro⁃scopic processes of enamel demineralization,laying the foundation for further research and treatment.
基金Project supported by the National Key Research and Development Program of China(Grant No.2021YFA1402103)the National Natural Science Foundation of China(Grant No.12393825)。
文摘Two-photon dissociation of BeH^(+)ions is studied by detecting the fluorescence changes of Be^(+)-BeH^(+)bi-component Coulomb crystal in a linear Paul trap.BeH^(+)ions generated by an exothermic reaction between electronically excited Be^(+)ions and residual H_(2) in the vacuum chamber are photon-dissociated with two photons scanning over the range of 201 nm to 208 nm.Our experiment provides a novel method to maintain the number of Be^(+)ions stable in a Coulomb crystal with a middle ultraviolet band dissociation laser.This two-photon dissociation method extends the wavelength range of the dissociation laser for BeH^(+)compared to the one-photon dissociation,and the method can be utilized to all alkaline earth atomic ions which require suppression of the reaction with residual H_(2) gas in vacuum.
基金funded by the National Natural Science Foundation of China(No.62305041)the Natural Science Foundation of Liaoning Province(No.2023-MS-103)。
文摘Stochastic optical reconstruction microscopy(STORM),as a typical technique of single-molecule localization microscopy(SMLM),has overcome the diffraction limit by randomly switching fluorophores between fluorescent and dark states,allowing for the precise localization of isolated emission patterns and the super-resolution reconstruction from millions of localized positions of single fluorophores.A critical factor influencing localization precision is the photo-switching behavior of fluorophores,which is affected by the imaging buffer.The imaging buffer typically comprises oxygen scavengers,photo-switching reagents,and refractive index regulators.Oxygen scavengers help prevent photobleaching,photo-switching reagents assist in facilitating the conversion of fluorophores,and refractive index regulators are used to adjust the refractive index of the solution.The synergistic interaction of these components promotes stable blinking of fluorophores,reduces irreversible photobleaching,and thereby ensures high-quality super-resolution imaging.This review provides a comprehensive overview of the essential compositions and functionalities of imaging buffers used in STORM,serving as a valuable resource for researchers seeking to select appropriate imaging buffers for their experiments.
基金National Natural Science Foundation of China(No.22264013)Hainan Province Clinical Medical Center(No.2021)Hainan Province Science and Technology Special Fund(No.ZDYF2024SHFZ104).
文摘Hypochlorous acid(HClO)is a critical biomolecule in living organisms,playing an essential role in numerous physiological or pathological processes.Abnormal levels of HClO in the body may lead to a series of diseases,for instance,inflammation and cancer.Thus,accurate measurement of HClO levels should be more beneficial for understanding its role in diseases and gaining a deeper insight into the pathogenesis of diseases.In this work,we designed a near-infrared two-photon fluorescent probe(HDM-Cl-HClO)for detecting fluctuations in HClO levels in inflammatory and tumor-bearing mice.Notably,the probe can respond to HClO within 5 s and trigger a brilliant red fluorescence at 660 nm.It exhibits high specificity and sensitivity for HClO.The superior spectral capability of the probe has enabled the detection of HClO levels in cells and zebrafish,as well as achieved the detection of HClO in inflammatory and tumor mice.This work not only provides a novel strategy and tool for HClO imaging in living systems,but also holds great potential for the diagnosis of inflammation and cancer.
基金supported by the National Key Research and Development Program of China(Grant Nos.2022YFA1403300 and 2019YFA0308404)the National Natural Science Foundation of China(Grant Nos.11427902,11991060,12074075,12474165,12274084,and 12241402)+5 种基金Shanghai Municipal Science and Technology Major Project(Grant No.2019SHZDZX01)Shanghai Municipal Natural Science Foundation(Grant No.22ZR1407400)Innovation Program for Quantum Science and Technology(Grant No.2024ZD0300104)Innovation Program of Shanghai Municipal Education Commission(Grant No.2023ZKZD03)Science and Technology Commission of Shanghai Municipality(Grant No.20JC1415900)China Postdoctoral Science Foundation(Grant No.KLH1512149).
文摘Recently,charged solitons have been found in a two-dimensional CoCl_(2)/HOPG system,whose microscopic nature remains to be elusive.In this work,we investigate the charged solitons in monolayer CoCl_(2) using scanning tunneling microscopy(STM)and atomic force microscopy(AFM).Moreover,we study the electrical properties of the charged solitons at zero electric field by measuring local contact potential difference(LCPD)via Kelvin probe force microscopy(KPFM)using the Δf(V)method.The compensation voltage corresponding to the vertex of the parabola is obtained by fitting the quadratic relationship between Δf and sample bias.The results show that,without an external electric field,the solitons behave as negatively charged entities.Meanwhile,the LCPD mapping characterizes the spatial distribution of the potential at the charged solitons,which agrees well with those obtained from STM band bending measurements.
基金supported by the Shandong Provincial Natural Science Foundation,China(No.ZR2020MA078)。
文摘Four benzocoumarin-based two-photon fluorescent probes(BH1-BH4)are proposed for ra-tiometric detection of hypochlorous acid(HClO)and their two-photon sensing perfor-mance are evaluated by means of time-dependent density func-tional theory and quadratic re-sponse theory.The effects of benzene-fused position on Stokes shift,fluorescence quantum yield and two-photon absorption are discussed comprehensively.The results show that fusing a benzene ring in coumarin can enhance Stokes shift efficiently.The benzene-fused position has important effects on these photophysical properties.The benzo[g]coumarins(BH1)and benzo[f]coumarins(BH2)derivatives have larger Stokes shifts in comparison with benzo[h]coumarins(BH3)and dihydrophenazine(BH4)derivatives.The two-photon absorp-tion of benzo[f]coumarins(BH2)derivative is much smaller than those of other benzo-coumarins derivatives.The large Stokes shift and increased two-photon action cross section can be achieved simultaneously in the dihydrophenazine(BH4)derivative.Therefore,the de-signed BH4 is expected to have superior performance for the ratiometric detection of HClO.To explore the reasons behind these effects,the intramolecular charge transfer degrees are il-lustrated quantitatively by plotting the hole-electron isosurface map,and the relation be-tween charge transfer and Stokes shift is revealed.A two-state model analysis is employed to understand two-photon absorption ability.Moreover,the fluorescence near-quenching mecha-nism of the product molecules B1 and B3 is explained by analyzing reorganization energy and Huang-Rhys factor,as well as related normal mode.Our research could contribute to the effi-cient design of ratiometric two-photon fluorescent probes with large Stokes shift and signifi-cant two-photon action cross section.
基金supported by the National Key R&D Program of China[Grant No.2022YFC2402400]the National Natural Science Foundation of China[Grant No.62275062]+2 种基金Project of Shandong Innovation and Startup Community of High-end Medical Apparatus and Instruments[Grant Nos.2023-SGTTXM-002 and 2024-SGTTXM-005]the Shandong Province Technology Innovation Guidance Plan(Central Leading Local Science and Technology Development Fund)[Grant No.YDZX2023115]the Taishan Scholar Special Funding Project of Shandong Province,and the Shandong Laboratory of Advanced Biomaterials and Medical Devices in Weihai[Grant No.ZL202402].
文摘Optical-resolution photoacoustic microscopy is a novel imaging technique that combines the advantages of optical and ultrasound imaging,enabling high-resolution visualization of biological tissues at the micrometer scale.However,the divergence of the excited Gaussian beam limits the depth-of-field of the system to less than 100μm,which hinders accurate three-dimensional imaging of living tissues and restrictsits applicability in biological research.Therefore,there is an urgent need for an effective method to enhance the depth-of-field without altering the hardware configuration.This paper presents a photoacoustic microscopy depth-of-field extension method and system based on three-dimensional continuity and sparsity deconvolution.This method utilizes a depth-varying point spread function and incorporates continuity and sparsity con-straints into the deconvolution process to mitigate the effect of background noise,enhancing the stability and accuracy of the depth-of-field extension.Experimental results using tungsten wire phantoms suggest that the depth-of-field of system can be extended to 650 pm,which is 7.2 times greater than conventional system,while improving the resolution of the defocused region by an average factor of 3.5.Furthermore,experiments on zebrafish and nude mouse ears with irregular topologies demonstrate that the proposed method successfully overcomes image blurring and the loss of structural information due to limited depth-of-field.All the results suggest that the system with higher lateral resolution and enhanced depth-of-field has significant potential for a wide range of practical biomedical applications.
基金supported by the National Natural Science Foundation of China[Grant Nos.62205367 and 62141506]the Suzhou Basic Research Pilot Project[Grant Nos.SSD2023006 and SJC2021013]the National Key Research and Development Program of China[Grant No.2023YFF1205700].
文摘Maintaining the s-polarization state of laser beams is important to achieve high modulation depth in a laser-interference-based super-resolution structured illumination microscope(SR-SIM).However,the imperfect optical components can depolarize the laser beams hence degenerating the modulation depth.Here,we first presented a direct measurement method designed to estimate the modulation depth more precisely by shifting illumination patterns with equal phase steps.This measurement method greatly reduces the dependence of modulation depths on the samples,and then developed a polarization optimization method to achieve high modulation depth at all orientations by actively and quantitatively compensating for the additional phase difference using a combination of waveplate and a liquid crystal variable retarder(LCVR).Experimental results demonstrate that our method can achieve illumination patterns with modulation depth higher than 0.94 at three orientations with only one LCVR voltage,which enables isotropic resolution improvement.
