Ultrasonic Lamb waves undergo complex mode conversion and diffraction at non-penetrating defects, such as plate corrosion and cracks. Lamb wave imaging has a resolution limit due to the guided wave dispersion characte...Ultrasonic Lamb waves undergo complex mode conversion and diffraction at non-penetrating defects, such as plate corrosion and cracks. Lamb wave imaging has a resolution limit due to the guided wave dispersion characteristics and Rayleigh criterion limitations. In this paper, a full convolutional network is designed to segment and reconstruct the received signals, enabling the automatic identification of target modalities. This approach eliminates clutter and mode conversion interference when calculating direct and accompanying acoustic fields in time-domain topological energy(TDTE) imaging.Subsequently, the measured accompanying acoustic field is reversed for adaptive focusing on defects and enhance the imaging quality. To circumvent the limitations of the Rayleigh criterion, the direct acoustic field and the accompanying acoustic field were fused to characterize the pixel distribution in the imaging region, achieving Lamb wave super-resolution imaging. Experimental results indicate that compared to the sign coherence factor-total focusing method(SCF-TFM),the proposed method achieves a 31.41% improvement in lateral resolution and a 29.53% increase in signal-to-noise ratio for single-blind-hole defects. In the case of multiple-blind-hole defects with spacings greater than the Rayleigh criterion resolution limit, it exhibits a 27.23% enhancement in signal-to-noise ratio. On the contrary, when the defect spacings are relatively smaller than the limit, this method has a higher resolution limit than SCF-TFM in super-resolution imaging.展开更多
Optical telescopes are an important tool for acquiring optical information about distant objects,and resolution is an important indicator that measures the ability to observe object details.However,due to the effects ...Optical telescopes are an important tool for acquiring optical information about distant objects,and resolution is an important indicator that measures the ability to observe object details.However,due to the effects of system aberration,atmospheric seeing,and other factors,the observed image of ground-based telescopes is often degraded,resulting in reduced resolution.This paper proposes an optical-neural network joint optimization method to improve the resolution of the observed image by co-optimizing the point-spread function(PSF)of the telescopic system and the image super-resolution(SR)network.To improve the speed of image reconstruction,we designed a generative adversarial net(LCR-GAN)with light parameters,which is much faster than the latest unsupervised networks.To reconstruct the PSF trained by the network in the optical path,a phase mask is introduced.It improves the image reconstruction effect of LCR-GAN by reconstructing the PSF that best matches the network.The results of simulation and verification experiments show that compared with the pure deep learning method,the SR image reconstructed by this method is rich in detail and it is easier to distinguish stars or stripes.展开更多
Super-resolution imaging is vital for optical applications, such as high capacity information transmission, real-time bio-molecular imaging, and nanolithography. In recent years, technologies and methods of super-reso...Super-resolution imaging is vital for optical applications, such as high capacity information transmission, real-time bio-molecular imaging, and nanolithography. In recent years, technologies and methods of super-resolution imaging have attracted much attention. Different kinds of novel lenses, from the superlens to the super-oscillatory lens, have been designed and fabricated to break through the diffraction limit. However, the effect of the super-resolution imaging in these lenses is not satisfactory due to intrinsic loss, aberration, large sidebands, and so on. Moreover, these lenses also cannot realize multiple super-resolution imaging. In this research, we introduce the solid immersion mechanism to Mikaelian lens(ML) for multiple super-resolution imaging. The effect is robust and valid for broadband frequencies. Based on conformal transformation optics as a bridge linking the solid immersion ML and generalized Maxwell's fish-eye lens(GMFEL), we also discovered the effect of multiple super-resolution imaging in the solid immersion GMFEL.展开更多
Carbohydrates on cell surfaces play a crucial role in a wide variety of biological processes,including cell adhesion,recognition and signaling,viral and bacterial infection,in°ammation and metastasis.However,owin...Carbohydrates on cell surfaces play a crucial role in a wide variety of biological processes,including cell adhesion,recognition and signaling,viral and bacterial infection,in°ammation and metastasis.However,owing to the large diversity and complexity of carbohydrate structure and nongenetically synthesis,glycoscience is the least understood¯eld compared with genomics and proteomics.Although the structures and functions of carbohydrates have been investigated by various conventional analysis methods,the distribution and role of carbohydrates in cell membranes remain elusive.This review focuses on the developments and challenges of super-resolution imaging in glycoscience through introduction of imaging principle and the available°uorescent probes for super-resolution imaging,the labeling strategies of carbohydrates,and the recent applications of super-resolution imaging in glycoscience,which will promote the super-resolution imaging technology as a promising tool to provide new insights into the study of glycoscience.展开更多
Purpose: To apply and evaluate a super-resolution scheme based on the super-resolution convolutional neural network (SRCNN) for enhancing image resolution in digital mammograms. Materials and Methods: A total of 711 m...Purpose: To apply and evaluate a super-resolution scheme based on the super-resolution convolutional neural network (SRCNN) for enhancing image resolution in digital mammograms. Materials and Methods: A total of 711 mediolateral oblique (MLO) images including breast lesions were sampled from the Curated Breast Imaging Subset of the Digital Database for Screening Mammography (CBIS-DDSM). We first trained the super-resolution convolutional neural network (SRCNN), which is a deep-learning based super-resolution method. Using this trained SRCNN, high-resolution images were reconstructed from low-resolution images. We compared the image quality of the super-resolution method and that obtained using the linear interpolation methods (nearest neighbor and bilinear interpolations). To investigate the relationship between the image quality of the SRCNN-processed images and the clinical features of the mammographic lesions, we compared the image quality yielded by implementing the SRCNN, in terms of the breast density, the Breast Imaging-Reporting and Data System (BI-RADS) assessment, and the verified pathology information. For quantitative evaluation, peak signal-to-noise ratio (PSNR) and structural similarity (SSIM) were measured to assess the image restoration quality and the perceived image quality. Results: The super-resolution image quality yielded by the SRCNN was significantly higher than that obtained using linear interpolation methods (p p Conclusion: SRCNN can significantly outperform conventional interpolation methods for enhancing image resolution in digital mammography. SRCNN can significantly improve the image quality of magnified mammograms, especially in dense breasts, high-risk BI-RADS assessment groups, and pathology-verified malignant cases.展开更多
We use the label-free microsphere-assisted microscopy to image low-contrast hexagonally close-packed polystyrene nanoparticle arrays with diameters of 300 and 250 nm.When a nanoparticle array is directly placed on a g...We use the label-free microsphere-assisted microscopy to image low-contrast hexagonally close-packed polystyrene nanoparticle arrays with diameters of 300 and 250 nm.When a nanoparticle array is directly placed on a glass slide,it cannot be distinguished.If a 30-nm-thick Ag film is deposited on the surface of a nanoparticle array,the nanoparticle array with nanoparticle diameters of 300 and 250 nm can be distinguished.In addition,the Talbot effect of the 300-nm-diameter nanoparticle array is also observed.If a nanoparticle sample is assembled on a glass slide deposited with a 30-nm-thick Ag film,an array of 300-nm-diameter nanoparticles can be discerned.We propose that in microsphere-assisted microscopy imaging,the resolution can be improved by the excitation of surface plasmon polaritons(SPPs) on the sample surface or at the sample/substrate interface,and a higher near-field intensity due to the excited SPPs would benefit the resolution improvement.Our study of label-free super-resolution imaging of low-contrast objects will promote the applications of microsphere-assisted microscopy in life sciences.展开更多
We present an imaging approach via sparsity constraint and sparse speckle illumination which can dramatically en- hance the optical system＇s imaging resolution. When the object is illuminated by some sparse speckles ...We present an imaging approach via sparsity constraint and sparse speckle illumination which can dramatically en- hance the optical system＇s imaging resolution. When the object is illuminated by some sparse speckles and the sparse reconstruction algorithm is utilized to restore the blur image, numerical simulated results demonstrate that the image, whose resolution exceeds the Rayleigh limit, can be stably reconstructed even if the detection signal-to-noise ratio （SNR） is less than 10 dB. Factors affecting the quality of the reconstructed image, such as the coded pattern＇s sparsity and the detection SNR, are also studied,展开更多
A fully convolutional encoder-decoder network(FCEDN),a deep learning model,was developed and applied to image scanning microscopy(ISM).Super-resolution imaging was achieved with a 78μm×78μm field of view and 12...A fully convolutional encoder-decoder network(FCEDN),a deep learning model,was developed and applied to image scanning microscopy(ISM).Super-resolution imaging was achieved with a 78μm×78μm field of view and 12.5 Hz-40 Hz imaging frequency.Mono and dual-color continuous super-resolution images of microtubules and cargo in cells were obtained by ISM.The signal-to-noise ratio of the obtained images was improved from 3.94 to 22.81 and the positioning accuracy of cargoes was enhanced by FCEDN from 15.83±2.79 nm to 2.83±0.83 nm.As a general image enhancement method,FCEDN can be applied to various types of microscopy systems.Application with conventional spinning disk confocal microscopy was demonstrated and significantly improved images were obtained.展开更多
Structured illumination microscopy has been a useful method for achieving lateral super-resolution,but it typically requires at least three precise phase shifts per orientation.In this paper,we propose a super-resolut...Structured illumination microscopy has been a useful method for achieving lateral super-resolution,but it typically requires at least three precise phase shifts per orientation.In this paper,we propose a super-resolution method that utilizes structured illumination without phase shift.The reconstruction process requires only a conventionally illuminated image and an image with structured illumination.This method achieves the same effect as the traditional phase shift method,and more than doubles the resolution by synthesizing a few reconstructions at different illumination frequencies.We verify the resolution improvement process using a combination of theoretical derivations and diagrams,and demonstrate its effectiveness with numerical simulations.展开更多
Significant advancements have been achieved in the field of Single Image Super-Resolution(SISR)through the utilization of Convolutional Neural Networks(CNNs)to attain state-of-the-art performance.Recent efforts have e...Significant advancements have been achieved in the field of Single Image Super-Resolution(SISR)through the utilization of Convolutional Neural Networks(CNNs)to attain state-of-the-art performance.Recent efforts have explored the incorporation of Transformers to augment network performance in SISR.However,the high computational cost of Transformers makes them less suitable for deployment on lightweight devices.Moreover,the majority of enhancements for CNNs rely predominantly on small spatial convolutions,thereby neglecting the potential advantages of large kernel convolution.In this paper,the authors propose a Multi-Perception Large Kernel convNet(MPLKN)which delves into the exploration of large kernel convolution.Specifically,the authors have architected a Multi-Perception Large Kernel(MPLK)module aimed at extracting multi-scale features and employ a stepwise feature fusion strategy to seamlessly integrate these features.In addition,to enhance the network's capacity for nonlinear spatial information processing,the authors have designed a Spatial-Channel Gated Feed-forward Network(SCGFN)that is capable of adapting to feature interactions across both spatial and channel dimensions.Experimental results demonstrate that MPLKN outperforms other lightweight image super-resolution models while maintaining a minimal number of parameters and FLOPs.展开更多
Fluorophores with controlled on–off switching properties and subcellular targeting abilities are essential for modern super-resolution microscopy techniques.However,the effective design strategies of blinking fluorop...Fluorophores with controlled on–off switching properties and subcellular targeting abilities are essential for modern super-resolution microscopy techniques.However,the effective design strategies of blinking fluorophores are still limited with scarce building blocks(e.g.,rhodamine and cyanine analogues),and sophisticated functionalization is always required for organelle recognition.Therefore,exploring live-cell compatible and organelle-targetable fluorophores with a new blinking mechanism is of broad interest to promote the emerging development of superresolution microscopy.Here,we report a type of live-cell permeable fluorophore with a facile synthesis strategy to facilitate the imaging of lipid droplets and lysosomes using single-molecule localization microscopy.The fluorophores only require a two-step synthetic route.They show signature enol-keto tautomerism by spontaneous proton transfer at the ground state without additional photoactivation,which ensures blinking performance by exciting the minor portion of molecules in keto form.This fluorescence switching mechanism provides a distinct character from that of previously reported live-cell permeable dyes for super-resolution imaging,while the specific organelle binding affinity can be tuned by simply changing the targeting moiety of fluorophores.展开更多
Theranostic visualization of dextran at the nanoscale is beneficial for understanding the bioregulatory mechanisms of this molecule. In this study, we applied structured illumination microscopy(SIM) to capture the dis...Theranostic visualization of dextran at the nanoscale is beneficial for understanding the bioregulatory mechanisms of this molecule. In this study, we applied structured illumination microscopy(SIM) to capture the distribution of Cy5-Dextran at different incubation periods in living cells. The results showed that Cy5-Dextran could be absorbed by He La cells. In addition, we clarified that Cy5-Dextran exhibited differential organelle distribution(lysosomal or mitochondrial) in a time-dependent manner. Moreover,lysosomal Cy5-Dextran localization was found to be independent of the autophagy process, while Cy5-Dextran localized to the mitochondria triggered a pro-apoptotic event, upregulating the levels of reactive oxygen species(ROS) to accelerate mitochondrial fragmentation. This work uses a visualized strategy to reveal the anti-tumor bioactivity of dextran, which was achieved by regulating apoptosis and autophagy.展开更多
The development of super-resolution technology has made it possible to investigate the ultrastructure of intracellular organelles by fuorescence microscopy,which has greatly facilitated the development of life science...The development of super-resolution technology has made it possible to investigate the ultrastructure of intracellular organelles by fuorescence microscopy,which has greatly facilitated the development of life sciences and biomedicine.To realize super-resolution imaging of living cells,both advanced imaging systems and excellent fuorescent probes are required.Traditional fuorescent probes have good availability,but that is not the case for probes for live-cell super-resolution imaging.In this review,we frst introduce the principles of various super-resolution technologies and their probe requirements,then summarize the existing designs and delivery strategies of super-resolution probes for live-cell imaging,and fnally provide a brief conclusion and overview of the future.展开更多
The need for temporal resolution and long-term stability in super-resolution fluorescence imaging has motivated research to improve the photostability of fluorescent probes.Due to the inevitable photobleaching of fluo...The need for temporal resolution and long-term stability in super-resolution fluorescence imaging has motivated research to improve the photostability of fluorescent probes.Due to the inevitable photobleaching of fluorophores,it is difficult to obtain long-term super-resolution imaging regardless of the self-healing strategy of introducing peroxide scavengers or the strategy of fluorophore structure modification to suppress TICT formation.The buffered fluorogenic probe uses the intact probes in the buffer pool to continuously replace the photobleached ones in the target,which greatly improves the photostability and enables stable dynamic super-resolution imaging for a long time.But the buffering capacity comes at the expense of reducing the number of fluorescent probes in targets,resulting in low staining fluorescence intensity.In this paper,we selected BODIPY 493,a lipid droplet probe with high fluorescence brightness,to explore the dynamic process of lipid droplet staining of this probe in cells.We found that BODIPY 493 only needs very low laser power for lipid droplet imaging due to the high molecular accumulation in lipid droplets and the high brightness,and the spatiotemporal resolution is greatly improved.More importantly,we found that BODIPY 493 also has a certain buffering capacity,which enables BODIPY 493 to be used for super-resolution imaging of lipid droplet dynamics.This work reminds researchers to coordinate the buffering capacity and brightness of fluorogenic probes.展开更多
The formation of amyloid plaques usually occurs in the early-stage of Alzheimer’s disease(AD).Stimulated emission depletion(STED)imaging provided a powerful tool for visualizing amyloid structures on the nanometer sc...The formation of amyloid plaques usually occurs in the early-stage of Alzheimer’s disease(AD).Stimulated emission depletion(STED)imaging provided a powerful tool for visualizing amyloid structures on the nanometer scale.However,many commercial probes adopted in detecting amyloid fibrils are inapplicable to STED imaging,owing to their unmatched absorption and emission wavelengths,small Stokes'shift,easy photo-bleaching,etc.Herein,we demonstrated a polarity-activated STED probe based on an intramolecular charge transfer donor(D)-7c-acceptor(A)compound.The electron-rich carbazole group and the electron-poor pyridinium bromide group,linked by 7i-conjugated thiophen-bridge,ensure strong near infrared(NIR)emission with a Stokes'shift larger than 200 nm.The tiny change in polarity before and after binding with amyloid plaques leads to a transition from weakly emission charge-transfer(CT)state(Φ<0.04)to highly emissive locally-excited(LE)state(Φ=0.57),giving rise to a fluorescence Turn-On probe.Together with large Stokes'shift,good photostability and high depletion efficiency,the super-resolution imaging of the formation and morphology of amyloid fibrils in vitro based on this probe was realized with a lateral spatial resolution better than 33 nm at an extremely low depletion power.Moreover,the ex-vivo super-resolution imaging of(E)-1-butyl-4(2-(5-(9-ethyl-9Hcarbazol-3-yl)thiophen-2-yl)vinyl)pyridinium bromide(CTPB)probe in Aβ plaques in the brain slices of a Tg mouse was demonstrated.This research provides a demonstration of the super resolution imaging probe of amyloid fibrils based on polarity-response mechanism,providing a new approach to the development of future amyloid probes.展开更多
Broadband super-resolution imaging is important in the optical field.To achieve super-resolution imaging,various lenses from a superlens to a solid immersion lens have been designed and fabricated in recent years.Howe...Broadband super-resolution imaging is important in the optical field.To achieve super-resolution imaging,various lenses from a superlens to a solid immersion lens have been designed and fabricated in recent years.However,the imaging is unsatisfactory due to low work efficiency and narrow band.In this work,we propose a solid immersion square Maxwell's fish-eye lens,which realizes broadband(7-16 GHz)achromatic super-resolution imaging with full width at half-maximum around 0.2λ based on transformation optics at microwave frequencies.In addition,a super-resolution information transmission channel is also designed to realize long-distance multi-source super-resolution information transmission based on the super-resolution lens.With the development of 3D printing technology,the solid immersion Maxwell's fish-eye lens is expected to be fabricated in the high-frequency band.展开更多
The combination of super-resolution microscopy and synthetic fluorescence probes has emerged as a universal tool to monitor dynamic biological events at the nanometer scale.However,the limited site-specificity and flu...The combination of super-resolution microscopy and synthetic fluorescence probes has emerged as a universal tool to monitor dynamic biological events at the nanometer scale.However,the limited site-specificity and fluorogenicity of synthetic fluorescent probes make it still difficult to realize long-term super-resolution imaging.Herein,we introduce a dynamic aggregation mediated SNAP-tag fluorogenic probe,BGAN-Aze,which can specifically bind to various SNAP-tag fusion proteins with 41-fold fluorescence enhancement.The equilibrium between the non-fluorescent aggregate/dimer(A–D)and the fluorescent monomer(M)of BGAN-Aze acts as an effective method to reduce the fluorescence background and endow BGAN-Aze with the capability of conducting washing-free super-resolution imaging of various intracellular and extracellular proteins.Using this probe,we monitored multiple dynamic biological events,such as MMC,mitophagy,the fusion of nucleolus,and the growth and contact of filopodia.We expect that BGAN-Aze will become a widely used SNAP-tag for super-resolution imaging of dynamic biological events and the A-D-M equilibrium can be a general strategy for designing fluorogenic probes.展开更多
Photocaged fluorophores with photoactivatable characteristics presented important applications in imaging the biological structures and processes.Taking advantage of their super-resolution imaging merits to manipulate...Photocaged fluorophores with photoactivatable characteristics presented important applications in imaging the biological structures and processes.Taking advantage of their super-resolution imaging merits to manipulate and visualize anti-cancer treatment is always a goal of modern clinical medicine.Traditional photodynamic therapy(PDT) is a noninvasive treatment but limited in intracellular oxygen content.Type I PDT and photoacid therapy(PAT) are two effective supplements of traditional PDT especially in hypoxic condition.Herein,a novel white-light-driven fluorescence switch(7H-dibenzo[c,g]carbazol-7-yl)(2-iodophenyl)methanone(2IB) was designed and synthesized as an unprecedent “all in one” platform for stochastic optical reconstruction microscopy(STORM) imaging guided Type Ⅰ/Ⅱ PDT and PAT.The experimental and theoretical studies revealed that the working mechanism is based on two competing paths under excitation:photosensitization and photocyclization reaction.Efficient intersystem crossing(ISC) ensured the generation of reactive oxygen species(ROS) for PDT,while low energy barrier facilitated the photocyclization reaction that simultaneously yielded emissive fluorophores(2IBC) and H^(+) for super-resolution imaging and photoacid,respectively.Impressively,the fluorescent intensity of mitochondria-targeted 2IBC was positively correlated with treatment efficacy,which is beneficial to spatiotemporally visualized therapeutic process and outcome.As a result,superior anti-tumor performance was achieved in vitro and in vivo.This contribution provided a multifunctional nanodrug paradigm for multimode cancer diagnosis and treatment.展开更多
Aggregation-induced emission(AIE)luminogens(AIEgens)with high brightness in aggregates exhibit great potentials in biological imaging,but these AIEgens are seldom applied in super-resolution biological imaging,especia...Aggregation-induced emission(AIE)luminogens(AIEgens)with high brightness in aggregates exhibit great potentials in biological imaging,but these AIEgens are seldom applied in super-resolution biological imaging,especially in the imaging by using the structural illumination microscope(SIM).Based on this consideration,we synthesized the donor-acceptor typed AIEgen of DTPA-BTN,which not only owns high brightness in the near-infrared(NIR)emission region from 600 nm to 1000 nm(photoluminescence quantum yield,PLQYs=11.35%),but also displays excellent photo-stability.In addition,AIE nanoparticles based on 4,7-ditriphenylamine-[1,2,5]-thiadiazolo[3,4-c]pyridine(DTPA-BTN)were also prepared with highly emissive features and excellent biocompatibility.Finally,the developed DTPA-BTN-based AIE nanoparticles were applied in the super-resolution cellular imaging via SIM,where much smaller full width at half-maximum values and high signal to noise ratios were obtained,indicating the superior imaging resolution.The results here imply that highly emissive AIEgens or AIE nanoparticles can be promising imaging agents for super-resolution imaging via SIM.展开更多
A full-polarimetric super-resolution algorithm with spatial smoothing processing is presented for one-dimensional（1-D）radar imaging.The coherence between scattering centers is minimized by using spatial smoothing pr...A full-polarimetric super-resolution algorithm with spatial smoothing processing is presented for one-dimensional（1-D）radar imaging.The coherence between scattering centers is minimized by using spatial smoothing processing（SSP）.Then the range and polarimetric scattering matrix of the scattering centers are estimated.The impact of different lengths of the smoothing window on the imaging quality is mainly analyzed with different signal-to-noise ratios（SNR）.Simulation and experimental results show that an improved radar super-resolution range profile and more precise estimation can be obtained by adjusting the length of the smoothing window under different SNR conditions.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No. 12174085)the Key Research and Development Project of Changzhou, Jiangsu Province, China (Grant No. CE20235054)the Postgraduate Research and Practice Innovation Program of Jiangsu Province, China (Grant No. KYCX24 0833)。
文摘Ultrasonic Lamb waves undergo complex mode conversion and diffraction at non-penetrating defects, such as plate corrosion and cracks. Lamb wave imaging has a resolution limit due to the guided wave dispersion characteristics and Rayleigh criterion limitations. In this paper, a full convolutional network is designed to segment and reconstruct the received signals, enabling the automatic identification of target modalities. This approach eliminates clutter and mode conversion interference when calculating direct and accompanying acoustic fields in time-domain topological energy(TDTE) imaging.Subsequently, the measured accompanying acoustic field is reversed for adaptive focusing on defects and enhance the imaging quality. To circumvent the limitations of the Rayleigh criterion, the direct acoustic field and the accompanying acoustic field were fused to characterize the pixel distribution in the imaging region, achieving Lamb wave super-resolution imaging. Experimental results indicate that compared to the sign coherence factor-total focusing method(SCF-TFM),the proposed method achieves a 31.41% improvement in lateral resolution and a 29.53% increase in signal-to-noise ratio for single-blind-hole defects. In the case of multiple-blind-hole defects with spacings greater than the Rayleigh criterion resolution limit, it exhibits a 27.23% enhancement in signal-to-noise ratio. On the contrary, when the defect spacings are relatively smaller than the limit, this method has a higher resolution limit than SCF-TFM in super-resolution imaging.
基金Funding is provided by the National Natural Science Foundation of China(NSFC,Grant Nos.62375027 and 62127813)Natural Science Foundation of Chongqing Municipality(CSTB2023NSCQ-MSX0504)+1 种基金Natural Science Foundation of Jilin Provincial(YDZJ202201ZYTS411)Jilin Provincial Education Department Fund of China(JJKH20240920KJ)。
文摘Optical telescopes are an important tool for acquiring optical information about distant objects,and resolution is an important indicator that measures the ability to observe object details.However,due to the effects of system aberration,atmospheric seeing,and other factors,the observed image of ground-based telescopes is often degraded,resulting in reduced resolution.This paper proposes an optical-neural network joint optimization method to improve the resolution of the observed image by co-optimizing the point-spread function(PSF)of the telescopic system and the image super-resolution(SR)network.To improve the speed of image reconstruction,we designed a generative adversarial net(LCR-GAN)with light parameters,which is much faster than the latest unsupervised networks.To reconstruct the PSF trained by the network in the optical path,a phase mask is introduced.It improves the image reconstruction effect of LCR-GAN by reconstructing the PSF that best matches the network.The results of simulation and verification experiments show that compared with the pure deep learning method,the SR image reconstructed by this method is rich in detail and it is easier to distinguish stars or stripes.
基金Project supported by the National Natural Science Foundation of China (Grant No. 92050102)the National Key Research and Development Program of China (Grant No. 2020YFA0710100)the Fundamental Research Funds for Central Universities, China (Grant Nos. 20720200074, 20720220134, 202006310051, and 20720220033)。
文摘Super-resolution imaging is vital for optical applications, such as high capacity information transmission, real-time bio-molecular imaging, and nanolithography. In recent years, technologies and methods of super-resolution imaging have attracted much attention. Different kinds of novel lenses, from the superlens to the super-oscillatory lens, have been designed and fabricated to break through the diffraction limit. However, the effect of the super-resolution imaging in these lenses is not satisfactory due to intrinsic loss, aberration, large sidebands, and so on. Moreover, these lenses also cannot realize multiple super-resolution imaging. In this research, we introduce the solid immersion mechanism to Mikaelian lens(ML) for multiple super-resolution imaging. The effect is robust and valid for broadband frequencies. Based on conformal transformation optics as a bridge linking the solid immersion ML and generalized Maxwell's fish-eye lens(GMFEL), we also discovered the effect of multiple super-resolution imaging in the solid immersion GMFEL.
基金This work was supported by NSFC (Grants 31330082,21373200,21525314)the Instrument Developing project of the Chinese Academy of Sciences (Grant YZ201455).
文摘Carbohydrates on cell surfaces play a crucial role in a wide variety of biological processes,including cell adhesion,recognition and signaling,viral and bacterial infection,in°ammation and metastasis.However,owing to the large diversity and complexity of carbohydrate structure and nongenetically synthesis,glycoscience is the least understood¯eld compared with genomics and proteomics.Although the structures and functions of carbohydrates have been investigated by various conventional analysis methods,the distribution and role of carbohydrates in cell membranes remain elusive.This review focuses on the developments and challenges of super-resolution imaging in glycoscience through introduction of imaging principle and the available°uorescent probes for super-resolution imaging,the labeling strategies of carbohydrates,and the recent applications of super-resolution imaging in glycoscience,which will promote the super-resolution imaging technology as a promising tool to provide new insights into the study of glycoscience.
文摘Purpose: To apply and evaluate a super-resolution scheme based on the super-resolution convolutional neural network (SRCNN) for enhancing image resolution in digital mammograms. Materials and Methods: A total of 711 mediolateral oblique (MLO) images including breast lesions were sampled from the Curated Breast Imaging Subset of the Digital Database for Screening Mammography (CBIS-DDSM). We first trained the super-resolution convolutional neural network (SRCNN), which is a deep-learning based super-resolution method. Using this trained SRCNN, high-resolution images were reconstructed from low-resolution images. We compared the image quality of the super-resolution method and that obtained using the linear interpolation methods (nearest neighbor and bilinear interpolations). To investigate the relationship between the image quality of the SRCNN-processed images and the clinical features of the mammographic lesions, we compared the image quality yielded by implementing the SRCNN, in terms of the breast density, the Breast Imaging-Reporting and Data System (BI-RADS) assessment, and the verified pathology information. For quantitative evaluation, peak signal-to-noise ratio (PSNR) and structural similarity (SSIM) were measured to assess the image restoration quality and the perceived image quality. Results: The super-resolution image quality yielded by the SRCNN was significantly higher than that obtained using linear interpolation methods (p p Conclusion: SRCNN can significantly outperform conventional interpolation methods for enhancing image resolution in digital mammography. SRCNN can significantly improve the image quality of magnified mammograms, especially in dense breasts, high-risk BI-RADS assessment groups, and pathology-verified malignant cases.
基金Project supported by the National Natural Science Foundation of China(Grant No.61673287)。
文摘We use the label-free microsphere-assisted microscopy to image low-contrast hexagonally close-packed polystyrene nanoparticle arrays with diameters of 300 and 250 nm.When a nanoparticle array is directly placed on a glass slide,it cannot be distinguished.If a 30-nm-thick Ag film is deposited on the surface of a nanoparticle array,the nanoparticle array with nanoparticle diameters of 300 and 250 nm can be distinguished.In addition,the Talbot effect of the 300-nm-diameter nanoparticle array is also observed.If a nanoparticle sample is assembled on a glass slide deposited with a 30-nm-thick Ag film,an array of 300-nm-diameter nanoparticles can be discerned.We propose that in microsphere-assisted microscopy imaging,the resolution can be improved by the excitation of surface plasmon polaritons(SPPs) on the sample surface or at the sample/substrate interface,and a higher near-field intensity due to the excited SPPs would benefit the resolution improvement.Our study of label-free super-resolution imaging of low-contrast objects will promote the applications of microsphere-assisted microscopy in life sciences.
基金Project supported by the National Natural Science Foundation of China(Grant No.61571427)
文摘We present an imaging approach via sparsity constraint and sparse speckle illumination which can dramatically en- hance the optical system＇s imaging resolution. When the object is illuminated by some sparse speckles and the sparse reconstruction algorithm is utilized to restore the blur image, numerical simulated results demonstrate that the image, whose resolution exceeds the Rayleigh limit, can be stably reconstructed even if the detection signal-to-noise ratio （SNR） is less than 10 dB. Factors affecting the quality of the reconstructed image, such as the coded pattern＇s sparsity and the detection SNR, are also studied,
基金Project supported by the China Postdoctoral Science Foundation,the National Key Research and Development Program of China for Y.S.(Grant No.2017YFA0505300)the National Science Foundation of China for Y.S.(Grant No.21825401)。
文摘A fully convolutional encoder-decoder network(FCEDN),a deep learning model,was developed and applied to image scanning microscopy(ISM).Super-resolution imaging was achieved with a 78μm×78μm field of view and 12.5 Hz-40 Hz imaging frequency.Mono and dual-color continuous super-resolution images of microtubules and cargo in cells were obtained by ISM.The signal-to-noise ratio of the obtained images was improved from 3.94 to 22.81 and the positioning accuracy of cargoes was enhanced by FCEDN from 15.83±2.79 nm to 2.83±0.83 nm.As a general image enhancement method,FCEDN can be applied to various types of microscopy systems.Application with conventional spinning disk confocal microscopy was demonstrated and significantly improved images were obtained.
基金supported by the National Natural Science Foundation of China(Grant No.51775381)National Key Scientific Instrument and Equipment Development Project(Grant No.2017YFF0107001)
文摘Structured illumination microscopy has been a useful method for achieving lateral super-resolution,but it typically requires at least three precise phase shifts per orientation.In this paper,we propose a super-resolution method that utilizes structured illumination without phase shift.The reconstruction process requires only a conventionally illuminated image and an image with structured illumination.This method achieves the same effect as the traditional phase shift method,and more than doubles the resolution by synthesizing a few reconstructions at different illumination frequencies.We verify the resolution improvement process using a combination of theoretical derivations and diagrams,and demonstrate its effectiveness with numerical simulations.
文摘Significant advancements have been achieved in the field of Single Image Super-Resolution(SISR)through the utilization of Convolutional Neural Networks(CNNs)to attain state-of-the-art performance.Recent efforts have explored the incorporation of Transformers to augment network performance in SISR.However,the high computational cost of Transformers makes them less suitable for deployment on lightweight devices.Moreover,the majority of enhancements for CNNs rely predominantly on small spatial convolutions,thereby neglecting the potential advantages of large kernel convolution.In this paper,the authors propose a Multi-Perception Large Kernel convNet(MPLKN)which delves into the exploration of large kernel convolution.Specifically,the authors have architected a Multi-Perception Large Kernel(MPLK)module aimed at extracting multi-scale features and employ a stepwise feature fusion strategy to seamlessly integrate these features.In addition,to enhance the network's capacity for nonlinear spatial information processing,the authors have designed a Spatial-Channel Gated Feed-forward Network(SCGFN)that is capable of adapting to feature interactions across both spatial and channel dimensions.Experimental results demonstrate that MPLKN outperforms other lightweight image super-resolution models while maintaining a minimal number of parameters and FLOPs.
基金supported by the Ministry of Science and Technology of China(grant no.2020YFA0908900)the National Natural Science Foundation of China(grant no.U21A2097)+5 种基金Key Technology Research and Development Program of Shandong(grant no.2021CXGC010212)Guangdong Provincial Key Laboratory of Advanced Biomaterials(grant no.2022B1212010003)Guangdong Natural Science Foundation Joint Fund(grant no.2020A1515110380)the Shenzhen Science and Technology Program(grant nos.KQTD20200820113012029 and JCYJ20220818100416036)the start-up fund provided by SUSTech for financial supportThe authors acknowledge the Center for Computational Science and Engineering at SUSTech for theoretical calculation support,and SUSTech Core Research Facilities for technical support.
文摘Fluorophores with controlled on–off switching properties and subcellular targeting abilities are essential for modern super-resolution microscopy techniques.However,the effective design strategies of blinking fluorophores are still limited with scarce building blocks(e.g.,rhodamine and cyanine analogues),and sophisticated functionalization is always required for organelle recognition.Therefore,exploring live-cell compatible and organelle-targetable fluorophores with a new blinking mechanism is of broad interest to promote the emerging development of superresolution microscopy.Here,we report a type of live-cell permeable fluorophore with a facile synthesis strategy to facilitate the imaging of lipid droplets and lysosomes using single-molecule localization microscopy.The fluorophores only require a two-step synthetic route.They show signature enol-keto tautomerism by spontaneous proton transfer at the ground state without additional photoactivation,which ensures blinking performance by exciting the minor portion of molecules in keto form.This fluorescence switching mechanism provides a distinct character from that of previously reported live-cell permeable dyes for super-resolution imaging,while the specific organelle binding affinity can be tuned by simply changing the targeting moiety of fluorophores.
基金supported by National Natural Science Foundation of China (Nos. 22107059, 21801158, 81870283, 82070382)Program of Taishan Scholars Programme (No. 20190979)+3 种基金Academic Promotion Programme of Shandong First Medical University (No.2019LJ003)National Postdoctoral Program for Innovative Talents(No. BX2021123)The China Postdoctoral Science Foundation (No.2021M691505)the Jiangsu Postdoctoral Research Funding Program (No. 2021K125B)。
文摘Theranostic visualization of dextran at the nanoscale is beneficial for understanding the bioregulatory mechanisms of this molecule. In this study, we applied structured illumination microscopy(SIM) to capture the distribution of Cy5-Dextran at different incubation periods in living cells. The results showed that Cy5-Dextran could be absorbed by He La cells. In addition, we clarified that Cy5-Dextran exhibited differential organelle distribution(lysosomal or mitochondrial) in a time-dependent manner. Moreover,lysosomal Cy5-Dextran localization was found to be independent of the autophagy process, while Cy5-Dextran localized to the mitochondria triggered a pro-apoptotic event, upregulating the levels of reactive oxygen species(ROS) to accelerate mitochondrial fragmentation. This work uses a visualized strategy to reveal the anti-tumor bioactivity of dextran, which was achieved by regulating apoptosis and autophagy.
基金supported by the National Key Research and Development Program of China(No.2022YFC3401100)the National Natural Science Foundation of China(Grant Nos.32271428,92054110,and 32201132)China Postdoctoral Science Foundation funded project(Nos.BX20220125 and 2022M711257).
文摘The development of super-resolution technology has made it possible to investigate the ultrastructure of intracellular organelles by fuorescence microscopy,which has greatly facilitated the development of life sciences and biomedicine.To realize super-resolution imaging of living cells,both advanced imaging systems and excellent fuorescent probes are required.Traditional fuorescent probes have good availability,but that is not the case for probes for live-cell super-resolution imaging.In this review,we frst introduce the principles of various super-resolution technologies and their probe requirements,then summarize the existing designs and delivery strategies of super-resolution probes for live-cell imaging,and fnally provide a brief conclusion and overview of the future.
基金supported by the National Natural Science Foundation of China(Nos.22078314,21878286,21908216).
文摘The need for temporal resolution and long-term stability in super-resolution fluorescence imaging has motivated research to improve the photostability of fluorescent probes.Due to the inevitable photobleaching of fluorophores,it is difficult to obtain long-term super-resolution imaging regardless of the self-healing strategy of introducing peroxide scavengers or the strategy of fluorophore structure modification to suppress TICT formation.The buffered fluorogenic probe uses the intact probes in the buffer pool to continuously replace the photobleached ones in the target,which greatly improves the photostability and enables stable dynamic super-resolution imaging for a long time.But the buffering capacity comes at the expense of reducing the number of fluorescent probes in targets,resulting in low staining fluorescence intensity.In this paper,we selected BODIPY 493,a lipid droplet probe with high fluorescence brightness,to explore the dynamic process of lipid droplet staining of this probe in cells.We found that BODIPY 493 only needs very low laser power for lipid droplet imaging due to the high molecular accumulation in lipid droplets and the high brightness,and the spatiotemporal resolution is greatly improved.More importantly,we found that BODIPY 493 also has a certain buffering capacity,which enables BODIPY 493 to be used for super-resolution imaging of lipid droplet dynamics.This work reminds researchers to coordinate the buffering capacity and brightness of fluorogenic probes.
基金This work was supported by the Ministry of Science and Technology of China(Nos.2017YFA0204503 and 2018YFA0704805)the National Natural Science Foundation of China(Nos.21503139,21573251,21673144,21873065,21833005,81970425 and 21790364)+5 种基金the Beijing Natural Science Foundation of China(No.2192011)the High-level Teachers in Bejing Municipal Universities in the Period of 13^th Five-year Plan(Nos.IDHT20180517 and CIT&TCD20180331)the Open Fund of the State Key Laboratory of Integrated Optoelectronics(No.IOSKL2019KF01)Capacity Building for Sci-Tech Innovation-Fundamental Scientific Research Funds(Nos.025185305000/210,009/19530050162 and 19530012018)Youth Innovative Research Team of Capital Normal University(No,009/19530050148)Beijing Advanced Innovation Center for Imaging Theory and Technology(No.009/19530011009).
文摘The formation of amyloid plaques usually occurs in the early-stage of Alzheimer’s disease(AD).Stimulated emission depletion(STED)imaging provided a powerful tool for visualizing amyloid structures on the nanometer scale.However,many commercial probes adopted in detecting amyloid fibrils are inapplicable to STED imaging,owing to their unmatched absorption and emission wavelengths,small Stokes'shift,easy photo-bleaching,etc.Herein,we demonstrated a polarity-activated STED probe based on an intramolecular charge transfer donor(D)-7c-acceptor(A)compound.The electron-rich carbazole group and the electron-poor pyridinium bromide group,linked by 7i-conjugated thiophen-bridge,ensure strong near infrared(NIR)emission with a Stokes'shift larger than 200 nm.The tiny change in polarity before and after binding with amyloid plaques leads to a transition from weakly emission charge-transfer(CT)state(Φ<0.04)to highly emissive locally-excited(LE)state(Φ=0.57),giving rise to a fluorescence Turn-On probe.Together with large Stokes'shift,good photostability and high depletion efficiency,the super-resolution imaging of the formation and morphology of amyloid fibrils in vitro based on this probe was realized with a lateral spatial resolution better than 33 nm at an extremely low depletion power.Moreover,the ex-vivo super-resolution imaging of(E)-1-butyl-4(2-(5-(9-ethyl-9Hcarbazol-3-yl)thiophen-2-yl)vinyl)pyridinium bromide(CTPB)probe in Aβ plaques in the brain slices of a Tg mouse was demonstrated.This research provides a demonstration of the super resolution imaging probe of amyloid fibrils based on polarity-response mechanism,providing a new approach to the development of future amyloid probes.
基金This work was supported by the National Key Research and Development Program of China(No.2020YFA0710100)National Natural Science Foundation of China(Nos.92050102 and 11874311)Fundamental Research Funds for the Central Universities(No.20720200074).
文摘Broadband super-resolution imaging is important in the optical field.To achieve super-resolution imaging,various lenses from a superlens to a solid immersion lens have been designed and fabricated in recent years.However,the imaging is unsatisfactory due to low work efficiency and narrow band.In this work,we propose a solid immersion square Maxwell's fish-eye lens,which realizes broadband(7-16 GHz)achromatic super-resolution imaging with full width at half-maximum around 0.2λ based on transformation optics at microwave frequencies.In addition,a super-resolution information transmission channel is also designed to realize long-distance multi-source super-resolution information transmission based on the super-resolution lens.With the development of 3D printing technology,the solid immersion Maxwell's fish-eye lens is expected to be fabricated in the high-frequency band.
基金National Natural Science Foundation of China,Grant/Award Numbers:22078314,21878286,21908216Dalian Institute of Chemical Physics,Grant/Award Numbers:DICPI202142,DICPI201938,DICPZZBS201805+1 种基金Advanced Manufacturing and Engineering Program,Grant/Award Number:A2083c0051Ministry of Education,Singapore,Grant/Award Number:MOE-MOET2EP10120-0007。
文摘The combination of super-resolution microscopy and synthetic fluorescence probes has emerged as a universal tool to monitor dynamic biological events at the nanometer scale.However,the limited site-specificity and fluorogenicity of synthetic fluorescent probes make it still difficult to realize long-term super-resolution imaging.Herein,we introduce a dynamic aggregation mediated SNAP-tag fluorogenic probe,BGAN-Aze,which can specifically bind to various SNAP-tag fusion proteins with 41-fold fluorescence enhancement.The equilibrium between the non-fluorescent aggregate/dimer(A–D)and the fluorescent monomer(M)of BGAN-Aze acts as an effective method to reduce the fluorescence background and endow BGAN-Aze with the capability of conducting washing-free super-resolution imaging of various intracellular and extracellular proteins.Using this probe,we monitored multiple dynamic biological events,such as MMC,mitophagy,the fusion of nucleolus,and the growth and contact of filopodia.We expect that BGAN-Aze will become a widely used SNAP-tag for super-resolution imaging of dynamic biological events and the A-D-M equilibrium can be a general strategy for designing fluorogenic probes.
基金supported by the Beijing Natural Science Foundation(Z210017)the National Natural Science Foundation of China(21774130,51925306)+4 种基金the National Key R&D Program of China(2018FYA 0305800)the Key Research Program of Frontier Sciences,Chinese Academy of Sciences(QYZDB-SSW-JSC046)the Strategic Priority Research ProgramChinese Academy of Sciences(XDB28000000)University of Chinese Academy of Sciences。
文摘Photocaged fluorophores with photoactivatable characteristics presented important applications in imaging the biological structures and processes.Taking advantage of their super-resolution imaging merits to manipulate and visualize anti-cancer treatment is always a goal of modern clinical medicine.Traditional photodynamic therapy(PDT) is a noninvasive treatment but limited in intracellular oxygen content.Type I PDT and photoacid therapy(PAT) are two effective supplements of traditional PDT especially in hypoxic condition.Herein,a novel white-light-driven fluorescence switch(7H-dibenzo[c,g]carbazol-7-yl)(2-iodophenyl)methanone(2IB) was designed and synthesized as an unprecedent “all in one” platform for stochastic optical reconstruction microscopy(STORM) imaging guided Type Ⅰ/Ⅱ PDT and PAT.The experimental and theoretical studies revealed that the working mechanism is based on two competing paths under excitation:photosensitization and photocyclization reaction.Efficient intersystem crossing(ISC) ensured the generation of reactive oxygen species(ROS) for PDT,while low energy barrier facilitated the photocyclization reaction that simultaneously yielded emissive fluorophores(2IBC) and H^(+) for super-resolution imaging and photoacid,respectively.Impressively,the fluorescent intensity of mitochondria-targeted 2IBC was positively correlated with treatment efficacy,which is beneficial to spatiotemporally visualized therapeutic process and outcome.As a result,superior anti-tumor performance was achieved in vitro and in vivo.This contribution provided a multifunctional nanodrug paradigm for multimode cancer diagnosis and treatment.
基金This work was supported by the National Natural Science Foundation of China(Nos.21975197,21674085,51603165)the Young Talent Fund of University Association for Science and Technology in Shaanxi Province,China(No.20180601)+3 种基金the Natural Science Basic Research Plan in Shaanxi Province of China(No.2019JM-040)the Key Laboratory Construction Program of Xi’an Municipal Bureau of Science and Technology,China(No.201805056ZD7CG40)the Innovation Capability Support Program of Shaanxi Province,China(Nos.2018PT-28,2019PT-05)school of Materials Science and Engineering,Jiangsu Engineering Laboratory of Light-Electricity-Heart Energy-coverting Materials and Applications,China(No.GDRGCS2019001).
文摘Aggregation-induced emission(AIE)luminogens(AIEgens)with high brightness in aggregates exhibit great potentials in biological imaging,but these AIEgens are seldom applied in super-resolution biological imaging,especially in the imaging by using the structural illumination microscope(SIM).Based on this consideration,we synthesized the donor-acceptor typed AIEgen of DTPA-BTN,which not only owns high brightness in the near-infrared(NIR)emission region from 600 nm to 1000 nm(photoluminescence quantum yield,PLQYs=11.35%),but also displays excellent photo-stability.In addition,AIE nanoparticles based on 4,7-ditriphenylamine-[1,2,5]-thiadiazolo[3,4-c]pyridine(DTPA-BTN)were also prepared with highly emissive features and excellent biocompatibility.Finally,the developed DTPA-BTN-based AIE nanoparticles were applied in the super-resolution cellular imaging via SIM,where much smaller full width at half-maximum values and high signal to noise ratios were obtained,indicating the superior imaging resolution.The results here imply that highly emissive AIEgens or AIE nanoparticles can be promising imaging agents for super-resolution imaging via SIM.
基金Supported by the National Naturral Science Foundation of China(61301191)
文摘A full-polarimetric super-resolution algorithm with spatial smoothing processing is presented for one-dimensional（1-D）radar imaging.The coherence between scattering centers is minimized by using spatial smoothing processing（SSP）.Then the range and polarimetric scattering matrix of the scattering centers are estimated.The impact of different lengths of the smoothing window on the imaging quality is mainly analyzed with different signal-to-noise ratios（SNR）.Simulation and experimental results show that an improved radar super-resolution range profile and more precise estimation can be obtained by adjusting the length of the smoothing window under different SNR conditions.
