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- 2017
- spectral reconstruction
- interference
- polarization
- transform
- imaging spectrometer
- Optoelectronic Information Science and Engineering
- BITTT
- Zhejiang University
- Guilin University of Aerospace Technology
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Observation of Acetylcholinesterase in Stress-induced Depression Phenotypes by Two-photon Fluorescence Imaging in the Mouse Brain
摘要： Oxidative stress in depression is a prime cause of neurotransmitter metabolism dysfunction in the brain. Acetylcholinesterase (AChE), a key hydrolase in the cholinergic system, directly determines the degradation of neurotransmitters. However, due to the complexity of the brain and lack of appropriate in situ imaging tools, the mechanism underlying the changes in AChE activity in depression remains unclear. Hence, we generated a two-photon fluorescence probe (MCYN) for real-time visualization of AChE with excellent sensitivity and selectivity. AChE can specifically recognize and cleave the carbamic acid ester bond in MCYN, and MCYN emits bright fluorescence at 560 nm by two-photon excitation at 800 nm. By utilizing MCYN to monitor AChE, we discovered a significant increase in AChE activity in the brains of mice with depression phenotypes. Notably, with the assistance of a two-photon fluorescence imaging probe of the superoxide anion radical (O2??), in vivo visualization for the first time revealed the positive correlation between AChE and O2?? levels associated with depressive behaviors. This finding suggests that oxidative stress may induce AChE overactivation, leading to depression-related behaviors. This work provides a new and rewarding perspective to elucidate the role of oxidative stress regulating AChE in the pathology of depression.
关键词： acetylcholinesterase,depression,Two-photon fluorescence imaging,brain,oxidative stress
更新于2025-09-23 15:23:52
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Frame-based Programming, Stream-Based Processing for Medical Image Processing Applications
摘要： This paper presents and evaluates an approach to deploy image and video processing pipelines that are developed frame-oriented on a hardware platform that is stream-oriented, such as an FPGA. First, this calls for a specialized streaming memory hierarchy and accompanying software framework that transparently moves image segments between stages in the image processing pipeline. Second, we use softcore VLIW processors, that are targetable by a C compiler and have hardware debugging capabilities, to evaluate and debug the software before moving to a High-Level Synthesis flow. The algorithm development phase, including debugging and optimizing on the target platform, is often a very time consuming step in the development of a new product. Our proposed platform allows both software developers and hardware designers to test iterations in a matter of seconds (compilation time) instead of hours (synthesis or circuit simulation time).
关键词： Image processing,FPGA,Medical imaging
更新于2025-09-23 15:23:52
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Rational Design of Near-Infrared AIE-Active Probes: In Situ Mapping of Amyloid-β Plaques with Ultra-Sensitivity and High-Fidelity
摘要： High-fidelity mapping of amyloid-β (Aβ) plaques is critical for the early detection of Alzheimer’s disease. However, in vivo probing of Aβ plaques by commercially available Thioflavin derivatives (ThT or ThS) has proven to be extremely limited, as evident by the restriction of enrichment quenching effect, low signal-to-noise (S/N) ratio and poor blood-brain barrier (BBB) penetrability. Herein, we demonstrate a rational design strategy of near-infrared (NIR) aggregation-induced emission (AIE)-active probes for Aβ plaques, through introducing lipophilic π-conjugated thiophene-bridge for extending to NIR wavelength with enhancement of BBB penetrability, and tuning the substituted position of sulfonate group for guaranteeing specific hydrophilicity to keep fluorescence-off state before binding to Aβ deposition. Probe QM-FN-SO3 has well settled the AIE dilemma between lipophilic requirement for longer emission and aggregation behavior from water to protein fibrillogenesis, thus making a breakthrough in high-fidelity feedback on in vivo detection of Aβ plaques with remarkable binding affinity, and serving as an efficient alternative to the commercial probe ThT or ThS.
关键词： Fluorescent probe,In vivo imaging,Aggregation-induced emission,Amyloid-β plaques,Near-infrared
更新于2025-09-23 15:23:52
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A new lysosome-targetable fluorescent probe with a large Stokes shift for detection of endogenous hydrogen polysulfides in living cells
摘要： Hydrogen polysulfides (H2Sn, n>1) influence a variety of important biological functions and activities associated with hydrogen sulfide (H2S). The development of probes for rapid, selective, and sensitive detection of H2Sn still remains a great challenge. Lysosome plays crucial roles in various physiological processes among living cells, which arouse high interest in detecting endogenous lysosome-targetable H2Sn. To the best of our knowledge, there is no lysosome-targetable probe for H2Sn has been reported. In this work, a new lysosome-targetable probe NIPY-NF, based on the scaffold of imidazo[1,5-α]pyridine, with a large Stokes shift (215 nm), low detection limit (84 nM), fast response time (6 min) and low cytotoxicity was designed and synthesized. Furthermore, NIPY-NF was successfully applied into the cell imaging for detection of endogenous lysosome-targetable H2Sn.
关键词： Hydrogen polysulfides,Fluorescent probe,Lysosome,Cell imaging,Imidazo[1,5-α]pyridine
更新于2025-09-23 15:23:52
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Functional imaging of visual cortical layers and subplate in awake mice with optimized three-photon microscopy
摘要： Two-photon microscopy is used to image neuronal activity, but has severe limitations for studying deeper cortical layers. Here, we developed a custom three-photon microscope optimized to image a vertical column of the cerebral cortex > 1 mm in depth in awake mice with low (<20 mW) average laser power. Our measurements of physiological responses and tissue-damage thresholds define pulse parameters and safety limits for damage-free three-photon imaging. We image functional visual responses of neurons expressing GCaMP6s across all layers of the primary visual cortex (V1) and in the subplate. These recordings reveal diverse visual selectivity in deep layers: layer 5 neurons are more broadly tuned to visual stimuli, whereas mean orientation selectivity of layer 6 neurons is slightly sharper, compared to neurons in other layers. Subplate neurons, located in the white matter below cortical layer 6 and characterized here for the first time, show low visual responsivity and broad orientation selectivity.
关键词： subplate neurons,deep brain imaging,visual cortex,neuronal activity,three-photon microscopy,GCaMP6s
更新于2025-09-23 15:23:52
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Targeting carbon nanotubes based on IGF-1R for photothermal therapy of orthotopic pancreatic cancer guided by optical imaging
摘要： Pancreatic cancer is one of the most lethal malignancies worldwide. The existing therapeutic regimen in the clinic for advanced inoperable carcinomas are far from satisfactory, thus it is urgent to seek more effective anticancer strategies. In the pursuit of novel, more effective interventions, photothermal therapy (PTT) based on nanomaterials has attracted increased attention. Recent advances in related fields have catalyzed the generation of novel nanoprobes, such as organic dyes, metal nanoparticles. However, organic dyes are poorly stable and easy to quench while metal nanoparticles with potential metal toxicity are difficult to degrade, both of which have low light-to-heat conversion efficiency, broad spectrum of anti-tumor effects, and lack of tumor targeting specificity. Single-walled carbon nanotubes (SWNTs) can remedy the above inadequacies. Herein, we report our water-soluble, bio-stable and low-toxicity SWNTs with excellent photothermal conversion efficiency. Specific modifications can enable visualization of the aggregate characteristics of SWNTs at the macroscopic or microscopic level in tumors. The dye-conjugated SWNTs bound with targeting antibodies that can induce them specifically targeting to pancreatic tumors for purposes of performing dyes imaging-guided cytotoxic PTT. PTT using this method achieves precise and excellent curative effects with minimal adverse effects, thus providing a promising strategy for anticancer therapy.
关键词： Single-walled carbon nanotubes,Imaging,IGF-1R,Pancreatic cancer,Photothermal therapy
更新于2025-09-23 15:23:52
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A robust and versatile platform for image scanning microscopy enabling super-resolution FLIM
摘要： Image scanning microscopy (ISM) can improve the effective spatial resolution of confocal microscopy to its theoretical limit. However, current implementations are not robust or versatile, and are incompatible with fluorescence lifetime imaging (FLIM). We describe an implementation of ISM based on a single-photon detector array that enables super-resolution FLIM and improves multicolor, live-cell and in-depth imaging, thereby paving the way for a massive transition from confocal microscopy to ISM.
关键词： super-resolution,SPAD array,fluorescence lifetime imaging,confocal microscopy,image scanning microscopy
更新于2025-09-23 15:23:52
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Thermal structure of a hot non-flaring corona from Hinode/EIS
摘要： Aims. In previous studies, a very hot plasma component has been diagnosed in solar active regions through the images in three different narrow-band channels of Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO). This diagnostic from extreme ultraviolet (EUV) imaging data has also been supported by the matching morphology of emission in the hot Ca XVII line, as observed with Extreme-Ultraviolet Imaging Spectrometer (EIS) on board Hinode. This evidence is debated because of the unknown distribution of the emission measure along the line of sight. Here we investigate in detail the thermal distribution of one such region using EUV spectroscopic data. Methods. In an active region observed with SDO/AIA, Hinode/EIS, and X-ray telescope (XRT), we select a sub-region with a very hot plasma component and another cooler sub-region for comparison. The average spectrum is extracted for both, and 14 intense lines are selected for analysis that probe the 5.5 < log T < 7 temperature range uniformly. From these lines, the emission measure distributions are reconstructed with the Markov-chain Monte Carlo method. Results are cross-checked in comparison with the two sub-regions, with a different inversion method, with the morphology of the images, and with the addition of fluxes measured with narrow, and broadband imagers. Results. We find that, whereas the cool region has a flat and featureless distribution that drops at temperature log T ≥ 6.3, the distribution of the hot region shows a well-defined peak at log T = 6.6 and gradually decreasing trends on both sides, thus supporting the very hot nature of the hot component diagnosed with imagers. The other cross-checks are consistent with this result. Conclusions. This study provides a completion of the analysis of active region components, and the resulting scenario supports the presence of a minor very hot plasma component in the core, with temperatures log T > 6.6.
关键词： techniques: imaging spectroscopy,Sun: UV radiation,Sun: corona,techniques: spectroscopic,Sun: X-rays, gamma rays
更新于2025-09-23 15:23:52
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One-dimensional integrals to calculate the two-dimensional Rayleigh–Sommerfeld diffraction integrals for non-rotationally symmetric functions and general polarizing illuminating fields
摘要： The recently reported (Alcalá Ochoa, 2018) approximation to the Rayleigh–Sommerfeld diffraction integrals (RSDI) is used to obtain a set of expressions to calculate the diffraction properties of non-rotationally symmetric optical systems illuminated with polarization fields. It is proved that the three two-dimensional integrals of RSDI can be expressed accurately from two to eight one-dimensional integrals depending of the type of polarization studied. It is proved also that previous developments based on Taylor’s approximations to the RSDI can be described by these new expressions.
关键词： Imaging optics,Diffraction,Fourier optics,Physical optics,Microscopy
更新于2025-09-23 15:23:52
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A cryogenic cylindrical ion trap velocity map imaging spectrometer
摘要： A cryogenic cylindrical ion trap velocity map imaging spectrometer has been developed to study photodissociation spectroscopy and dynamics of gaseous molecular ions and ionic complexes. A cylindrical ion trap made of oxygen-free copper is cryogenically cooled down to ～7 K by using a closed cycle helium refrigerator and is coupled to a velocity map imaging (VMI) spectrometer. The cold trap is used to cool down the internal temperature of mass selected ions and to reduce the velocity spread of ions after extraction from the trap. For CO2+ ions, a rotational temperature of ～12 K is estimated from the recorded [1 + 1] two-photon dissociation spectrum, and populations in spin-orbit excited X2Πg,1/2 and vibrationally excited states of CO2+ are found to be non-detectable, indicating an efficient internal cooling of the trapped ions. Based on the time-of-flight peak profile and the image of N3+ ions, the velocity spread of the ions extracted from the trap, both radially and axially, is interpreted as approximately ±25 m/s. An experimental image of fragmented Ar+ from 307 nm photodissociation of Ar2+ shows that, benefiting from the well-confined velocity spread of the cold Ar2+ ions, a VMI resolution of Δv/v ～ 2.2% has been obtained. The current instrument resolution is mainly limited by the residual radial speed spread of the parent ions after extraction from the trap.
关键词： cryogenic ion trap,velocity map imaging,ion cooling,photodissociation,spectroscopy
更新于2025-09-23 15:23:52