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过滤筛选
- 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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Investigation of Keratinizing Squamous Cell Carcinoma of the Tongue Using Terahertz Reflection Imaging
摘要： We investigated the feasibility of using terahertz (THz) reflection imaging to detect keratinizing squamous cell carcinoma (SCC) of the tongue. Four fresh keratinizing SCC tissues were studied, which had been surgically resected. All of the keratinizing SCCs were well distinguished from normal healthy tissues. We showed that the tumor regions exhibited low THz reflection despite having higher water content than normal regions. The refractive indices and absorption coefficients were low in the tumor tissues despite the relatively high water content. Our results showed that there were dominant factors such as keratin pearls, other than the water content affecting the THz reflection signal.
关键词： Optical diagnostics for medicine,Tissue diagnostics,Terahertz imaging,Medical and biological imaging,Terahertz spectroscopy
更新于2025-09-23 15:23:52
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Electromagnetically induced holographic imaging with Rydberg atoms
摘要： Electromagnetically induced holographic imaging using strongly interacting Rydberg atoms is investigated via electromagnetically induced grating (EIG). We consider two schemes, i.e., by direct detection of holographic imaging pattern, known as electromagnetically induced classical holographic imaging (EICHI), and by employing entangled photon pairs for imaging which is called as electromagnetically induced quantum holographic imaging (EIQHI). Both the schemes are employed to obtain 1D and 2D holographic imaging. In EICHI and EIQHI, amplitude and phase information of EIG can be imaged with controllable image variation in size. It is noticed that holographic imaging is influenced by van der Waals (vdW) effect present in Rydberg atoms.
关键词： Electromagnetically induced grating,Rydberg atoms,Quantum imaging,Electromagnetically induced holographic imaging,van der Waals effect
更新于2025-09-23 15:23:52
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Evaluation of the effect of image noise on CT perfusion measurements using digital perfusion phantoms
摘要： Objectives To assess the influence of image noise on computed tomography (CT) perfusion studies, CT perfusion software algorithms were evaluated for susceptibility to image noise and results applied to clinical perfusion studies. Methods Digital perfusion phantoms were generated using a published deconvolution model to create time-attenuation curves (TACs) for 16 different combinations of blood flow (BF; 30/60/90/120 ml/100 ml/min) and flow extraction product (FEP; 10/20/30/40 ml/100 ml/min) corresponding to values encountered in clinical studies. TACs were distorted with Gaussian noise at 50 different strengths to approximate image noise, performing 200 repetitions for each noise level. A total of 160,000 TACs were evaluated by measuring BF and FEP with CT perfusion software, comparing results for the maximum slope and Patlak models with those obtained with a deconvolution model. To translate results to clinical practice, data of 23 patients from a CT perfusion study were assessed for image noise, and the accuracy of reported CT perfusion measurements was estimated. Results Perfusion measurements depend on image noise as means and standard deviations of BF and FEP over repetitions increase with increasing image noise, especially for low BF and FEP values. BF measurements derived by deconvolution show larger standard deviations than those performed with the maximum slope model. Image noise in the evaluated CT perfusion study was 26.46 ± 3.52 HU, indicating possible overestimation of BF by up to 85% in a clinical setting. Conclusions Measurements of perfusion parameters depend heavily upon the magnitude of image noise, which has to be taken into account during selection of acquisition parameters and interpretation of results, e.g., as a quantitative imaging biomarker.
关键词： Tomography, x-ray computed,Phantoms, imaging,Perfusion imaging,Software,Artifacts
更新于2025-09-23 15:23:52
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Probing Polarity and Heterogeneity of Lipid Droplets in Live Cells Using a Push–Pull Fluorophore
摘要： Lipid droplets (LDs) are organelles composed of a lipid core surrounded by a phospholipid monolayer. Lately, LDs attracted a considerable attention due to recent studies demonstrating their role in a variety of physiological processes as well as diseases. Herein we synthesized a push-pull molecule named DAF (Dimethyl Aniline Furaldehyde) that possesses a strong positive solvatochromism in emission of 119 nm from toluene to methanol. Its impressive fluorogenic properties from water to oil (2000-fold) as well as its high quantum yields (up to 0.97) led us to investigate its ability to sense the distribution of polarity in live cells by fluorescence ratiometric imaging. When added to live cells and excited at 405 nm, DAF immediately and brightly stain lipid droplets using a blue channel (410-500 nm) and cytoplasm in a red channel (500-600 nm). DAF also proved to be compatible with fixation thus allowing 3D imaging of LDs in their cytoplasm environment. Taking advantage of DAF emission in two distinct channels, ratiometric imaging was successfully performed and led to the polarity mapping of the cell unraveling some heterogeneity in polarity within LDs of the same cell.
关键词： Environment Sensitive Fluorescent Probe,Lipid Droplets,Ratiometric Imaging,Multicolor Fluorescent imaging
更新于2025-09-23 15:23:52
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Non-Invasive Optical Guided Tumor Metastasis/Vessel Imaging by Using Lanthanide Nanoprobe with Enhanced Down-Shifting Emission beyond 1500 nm
摘要： Visualization of tumor vessels/metastasis and cerebrovascular architecture is vital important for analyzing pathological states of brain diseases and tumor's abnormal blood vessel to improve cancer diagnosis. In vivo fluorescence imaging using second near infrared emission beyond 1500 nm (NIR-IIb) is emerged as a next generation optical imaging method with significant improvement in imaging sensitivity and spatial resolution. Unfortunately, highly biocompatible probe capable of generating NIR-IIb emission with sufficient brightness and uniformed size is still scarce. Here, we have proposed the polyacrylic acid (PAA)-modified NaLnF4:40Gd/20Yb/2Er nanorods (Ln=Y, Yb, Lu, PAA-Ln-NRs) with enhanced downshifting NIR-IIb emission, high quantum yield (QY), relative narrow bandwidth (~160 nm) and high bio-compatibility via Ce3+ doping for high performance NIR-IIb bioimaging. The downshifting emission beyond 1500 nm is improved by 1.75~2.2 times with simultaneously suppressing the upconversion (UC) path in Y, Yb, and Lu hosts via Ce3+ doping. Moreover, compared with the traditionally used Y-based host, the QY of NIR-IIb emission in Lu-based probe in water is improved from 2.2% to 3.6%. The explored bright NIR-IIb emitted PAA-Lu-NRs were used for high sensitivity small tumor (~ 4 mm)/metastatic tiny tumor detection (~ 3 mm), tumor vessel visualization with high spatial resolution (41 μm) and brain vessel imaging. Therefore, our findings open up the opportunity of utilizing lanthanide based NIR-IIb probe with bright 1525 nm emission for in vivo optical-guided tumor vessel/metastasis and non-invasive brain vascular imaging.
关键词： enhancement of downshifting emission,tiny metastatic tumor detection,tumor vascular imaging,rare-earth nanoprobes,brain vascular imaging
更新于2025-09-23 15:23:52
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A Novel Chemiluminescent Probe Based on 1,2-Dioxetane Scaffold for Imaging Cysteine in Living Mice
摘要： A novel chemiluminescent probe for detection of cysteine (Cys) from other biothiols has been reported by utilizing the excellent chemiluminescent Schaap’s adamantylidene-dioxetane scaffold. After careful assessment, the probe CL-Cys could detect Cys with high sensitivity and total light photons increased with 28-fold after the probe was treated with Cys, with the detection limit of 7.5 x 10-8 M. Finally, CL-Cys was further utilized to the chemiluminescent imaging of endogenous Cys in living mouse. In general, this probe has a remarkable ability of detecting Cys, which provides a valuable method for interrogation the Cys roles in more biological and pathological processes.
关键词： Chemiluminescent probe,1,Cysteine,2-dioxetane,Chemiluminescent imaging,In vivo imaging.,Living animal
更新于2025-09-23 15:23:52
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Improved immuno-PET imaging of HER2-positive tumors in mice: Urokinase injection-triggered clearance enhancement of <sup>64</sup> Cu-trastuzumab
摘要： Immuno-positron emission tomography (immuno-PET) is expected to improve the specificity of small chemical tracers such as 18F-fluorodeoxyglucose. Whole antibodies significantly accumulate in target molecule-expressing tumors but frequently persist too long in the blood circulation for imaging purposes. We investigated the utility of whole antibodies, 64Cu-labeled via a urokinase-substrate linker, and their exogenous urokinase-responsive cleavage to enhance clearance of immuno-PET probes from the blood and shorten the time required to develop adequate imaging contrast. Specifically, we used 64Cu-labeled trastuzumab in human epidermal growth factor receptor 2 (HER2)-positive tumor-bearing mice. 64Cu-labeled trastuzumab with a urokinase-cleavage site (64Cu-CB-TE1A1P-USL-trastuzumab) was synthesized using a bifunctional chelator incorporating a urokinase substrate peptide. Urokinase cleavage was analyzed in vitro by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and radio-gel permeation-high performance liquid chromatography. Improvements in radioisotope clearance and HER2-imaging by urokinase injection were evaluated by PET imaging and ex vivo biodistribution studies in A431 tumor-bearing mice. 64Cu-CB-TE1A1P-USL-trastuzumab was cleaved into smaller radioactive fragments by 20,000 IU/mL urokinase treatment in vitro at an efficacy of ~95%. The probe targeted HER2 in A431 tumors in mice within 24 h post-injection, and approximately two-thirds of the probe in the blood circulation was eliminated via renal clearance of radioactive fragments after three urokinase injections. Therefore, the tumor/blood ratio increased 3.0-fold. Without urokinase injection, the tumor accumulation of 64Cu-CB-TE1A1P-USL-trastuzumab slowly increased and the blood radioactivity decreased over 72 h. However, the tumor/blood ratios in mice after three urokinase injections were higher at 24 h than those in mice without injections at 72 h. The results indicate that our approach shortened the time required to develop adequate imaging contrast of immuno-PET by > 2 days. Therefore, this approach can benefit high-sensitivity imaging under lower radioactive decay conditions and can decrease patient radiation exposure. In addition, it could reduce other adverse effects of radioimmunotherapy.
关键词： immuno-positron emission tomography,cancer imaging,trastuzumab,urokinase,imaging contrast,clearance enhancement
更新于2025-09-23 15:23:52
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A Radio-Fluorogenic Polymer-Gel Makes Fixed Fluorescent Images of Complex Radiation Fields
摘要： We review the development and application of an organic polymer-gel capable of producing fixed, three-dimensional fluorescent images of complex radiation fields. The gel consists for more than 99% of γ-ray-polymerized (~15% conversion) tertiary-butyl acrylate (TBA) containing ~100 ppm of a fluorogenic compound, e.g., maleimido-pyrene (MPy). The radio-fluorogenic effect depends on copolymerization of the MPy into growing chains of TBA on radiation-induced polymerization. This converts the maleimido residue, which quenches the pyrene fluorescence, into a succinimido moiety (SPy), which does not. The intensity of the fluorescence is proportional to the yield of free-radicals formed and hence to the local dose deposited. Because the SPy moieties are built into the polymer network, the image is fixed. The method of preparing the gel and imaging the radiation-induced fluorescence are presented and discussed. The effect is illustrated with fluorescent images of the energy deposited in the gel by beams of X-rays, electrons, and protons as well as a radioactive isotope.
关键词： polymer gel dosimetry,radio-fluorogenic co-polymerization,radio-fluorogenic gel,3D dose imaging,proton beam imaging,tertiary-butyl acrylate gel
更新于2025-09-23 15:23:52
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A miniature multi-contrast microscope for functional imaging in freely behaving animals
摘要： Neurovascular coupling, cerebrovascular remodeling and hemodynamic changes are critical to brain function, and dysregulated in neuropathologies such as brain tumors. Interrogating these phenomena in freely behaving animals requires a portable microscope with multiple optical contrast mechanisms. Therefore, we developed a miniaturized microscope with: a fluorescence (FL) channel for imaging neural activity (e.g., GCaMP) or fluorescent cancer cells (e.g., 9L-GFP); an intrinsic optical signal (IOS) channel for imaging hemoglobin absorption (i.e., cerebral blood volume); and a laser speckle contrast (LSC) channel for imaging perfusion (i.e., cerebral blood flow). Following extensive validation, we demonstrate the microscope’s capabilities via experiments in unanesthetized murine brains that include: (i) multi-contrast imaging of neurovascular changes following auditory stimulation; (ii) wide-area tonotopic mapping; (iii) EEG-synchronized imaging during anesthesia recovery; and (iv) microvascular connectivity mapping over the life-cycle of a brain tumor. This affordable, flexible, plug-and-play microscope heralds a new era in functional imaging of freely behaving animals.
关键词： freely behaving animals,multi-contrast imaging,neurovascular coupling,miniaturized microscope,functional imaging
更新于2025-09-23 15:23:52
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Multimodal hard x-ray imaging with resolution approaching 10 nm for studies in material science
摘要： We report multimodal scanning hard x-ray imaging with spatial resolution approaching 10 nm and its application to contemporary studies in the field of material science. The high spatial resolution is achieved by focusing hard x-rays with two crossed multilayer Laue lenses and raster-scanning a sample with respect to the nanofocusing optics. Various techniques are used to characterize and verify the achieved focus size and imaging resolution. The multimodal imaging is realized by utilizing simultaneously absorption-, phase-, and fluorescence-contrast mechanisms. The combination of high spatial resolution and multimodal imaging enables a comprehensive study of a sample on a very fine length scale. In this work, the unique multimodal imaging capability was used to investigate a mixed ionic-electronic conducting ceramic-based membrane material employed in solid oxide fuel cells and membrane separations (compound of Ce0.8Gd0.2O2?x and CoFe2O4) which revealed the existence of an emergent material phase and quantified the chemical complexity at the nanoscale.
关键词： mixed ionic-electronic conducting membrane,x-ray nanoscale imaging,multimodal imaging,high spatial resolution
更新于2025-09-23 15:23:52