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Anefficient quadrature demodulator for medical ultrasound imaging

Hao ZHOU,Yin-fei ZHENG

《信息与电子工程前沿（英文）》 2015年第16卷第4期页码 301-310 doi: 10.1631/FITEE.1400205

摘要： Quadrature demodulation is used in medical ultrasound imaging to derive the envelope and instantaneous phase of the received radio-frequency (RF) signal. In quadrature demodulation, RF signal is multiplied with the sine and cosine wave reference signal and then low-pass filtered to produce the base-band complex signal, which has high computational complexity. In this paper, we propose an efficient quadrature demodulation method for B-mode and color flow imaging, in which the RF signal is demodulated by a pair of finite impulse response filters without mixing with the reference signal, to reduce the computational complexity. The proposed method was evaluated with simulation and in vivo experiments. From the simulation results, the proposed quadrature demodulation method produced similar normalized residual sum of squares (NRSS) and velocity profile compared with the conventional quadrature demodulation method. In the in vivo color flow imaging experiments, the time of the demodulation process was 5.66 ms and 3.36 ms, for the conventional method and the proposed method, respectively. These results indicated that the proposed method can maintain the performance of quadrature demodulation while reducing computational complexity.

关键词： B-mode ultrasound imaging Color flow imaging Quadrature demodulation Finite impulse response filter

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Characterization of 3D microstructure, thermal conductivity, and heat flow of cement-based foam usingimaging technique

《结构与土木工程前沿（英文）》 2021年第15卷第3期页码 643-651 doi: 10.1007/s11709-021-0709-9

摘要： This study presents the results of the 3D microstructure, thermal conductivity, and heat flow in cement-based foams and examines their changes with a range of densities. Images were captured using X-ray micro computed tomography (micro-CT) imaging technique on cement-based foam samples prepared with densities of 400, 600, and 800 kg/m³. These images were later simulated and quantified using 3D data visualization and analysis software. Based on the analysis, the pore volume of 11000 µm³ was determined across the three densities, leading to optimal results. However, distinct pore diameters of 15 µm for 800 kg/m³, and 20 µm for 600 and 400 kg/m³ were found to be optimum. Most of the pores were spherical, with only 10% appearing elongated or fractured. In addition, a difference of 15% was observed between the 2D and 3D porosity results. Moreover, a difference of 5% was noticed between the experimentally measured thermal conductivity and the numerically predicted value and this variation was constant across the three cast densities. The 3D model showed that heat flows through the cement paste solids and with an increase in porosity this flow reduces.

关键词： 3D pore volume distribution X-ray tomography 3D shape factor heat flow

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彩色测温方法中物体辐射色域的界定和划分

王安全,程晓舫,陆少松

《中国工程科学》 2002年第4卷第8期页码 54-57

摘要：

介绍了彩色测温方法的基本原理，并基于可见光波段内光谱发射率的线性模型给出物体辐射颜色色品的表述；明确了一个色品最多只能求解出两个温度；解决了彩色测温方法中物体辐射色域的界定问题，并将辐射色域划分为温度单解域和双解域。

关键词：辐射测温彩色测温色域发射率

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我国海洋水色遥感应用工程技术的新进展

潘德炉,白雁

《中国工程科学》 2008年第10卷第9期页码 14-24

摘要：

介绍了近年来我国在海洋水色遥感应用工程技术方面的新进展，包括以应用为导向的关键技术研究和各类应用示范系统的开发等。针对当前海洋水色遥感业务化应用服务所面临的问题和一些急需解决的关键工程技术进行了分析和展望。

关键词：海洋水色遥感业务化应用中国海洋一号卫星

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Investigations on color variations of Morpho rhetenor butterfly wing scales

Guanglan LIAO, Haibo ZUO, Xuan JIANG, Xuefeng YANG, Tielin SHI

《机械工程前沿（英文）》 2012年第7卷第4期页码 394-400 doi: 10.1007/s11465-012-0347-y

摘要：

Experiments and simulations are carried out to investigate the optical properties of butterfly wing scales. The upper surface of a male butterfly wing presents a single-layer of scales, the microstructures of which are responsible for the brilliant blue color. The color varies from cyan blue to yellow green and soon afterwards returns back to cyan blue when some ethanol is dropped on the upper surface. At the start of the ethanol volatilization process, the reflection spectrum remains stable. As the ethanol further volatilizes, the peak reflectance decreases slightly, then increases dramatically. Meanwhile, the peak wavelength keeps approximately constant, then decreases, and keeps almost stable at the end of the process. Therefore, the optical properties depend strongly on the varying ambient conditions, including the refractive index and the thickness of the packing medium. Moreover, the possible causes for the scales in dark green region after several dropping ethanol experiments are clarified. This research benefits our understanding of the color variation mechanisms of the wing scales, and provides inspiration for further studies and applications.

关键词： Morpho rhetenor microstructures color variations ambient medium

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evaluation of renal function using diffusion weighted imaging and diffusion tensor imaging in type 2

null

《医学前沿（英文）》 2014年第8卷第4期页码 471-476 doi: 10.1007/s11684-014-0365-8

摘要：

This work aims to estimate the value of diffusion weighted imaging (DWI) and diffusion tensor imaging (DTI) in detecting early-stage kidney injury in type 2 diabetic patients with normoalbuminuria (NAU) versus microalbuminuria (MAU) prospectively. A total of 30 T2DM patients with normal kidney function were recruited and assigned to the NAU group (n = 14) or MAU group (n= 16) according to 8 h overnight urinary albuminuria excretion rate (AER) results. A contemporary cohort of health check-up recipients were included as controls (n = 12). DWI and DTI scans were performed on bilateral kidney using SE single-shot EPI, and apparent diffusion coefficient (ADC) and fractional anisotropy (FA) of the renal parenchyma was determined from ADC and FA maps of the three groups. ADC and FA values were compared among the three groups. According to DWI with a b value of 400 s/mm², the MAU and NAU groups showed significantly lowered mean ADC values compared with the healthy controls (P<0.01). The mean ADC in the MAU group [(2.22±0.07)×10^–3 mm²/s] was slightly lower than that of the NAU group [(2.31±0.22)×10^–3 mm²/s], but this difference was not statistically significant (P>0.05). The FA value in the MAU group was higher than that in the control group (0.45±0.07 vs. 0.39±0.03, P = 0.004) but did not differ from that in the NAU group (0.42±0.03) (P>0.05). ADC and FA values may be more sensitive than urine AER in reflecting early-stage kidney injury and, hence, may facilitate earlier detection and quantitative evaluation of kidney injury in T2DM patients. Combined evaluation of ADC and FA values may provide a better quantitative approach for identifying diabetic nephropathy at early disease stages.

关键词： type 2 diabetes mellitus microalbuminuria diffusion weighted imaging diffusion tensor imaging early-stage kidney injury

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Multi-color space threshold segmentation and self-learning k-NN algorithm for surge test EUT status

Jian HUANG,Gui-xiong LIU

《机械工程前沿（英文）》 2016年第11卷第3期页码 311-315 doi: 10.1007/s11465-016-0376-z

摘要：

The identification of targets varies in different surge tests. A multi-color space threshold segmentation and self-learning k-nearest neighbor algorithm (k-NN) for equipment under test status identification was proposed after using feature matching to identify equipment status had to train new patterns every time before testing. First, color space (L*a*b*, hue saturation lightness (HSL), hue saturation value (HSV)) to segment was selected according to the high luminance points ratio and white luminance points ratio of the image. Second, the unknown class sample S_r was classified by the k-NN algorithm with training set T_z according to the feature vector, which was formed from number of pixels, eccentricity ratio, compactness ratio, and Euler’s numbers. Last, while the classification confidence coefficient equaled k, made S_r as one sample of pre-training set T_z′. The training set T_z increased to T_z₊₁ by T_z′ if T_z′ was saturated. In nine series of illuminant, indicator light, screen, and disturbances samples (a total of 21600 frames), the algorithm had a 98.65% identification accuracy, also selected five groups of samples to enlarge the training set from T₀ to T₅ by itself.

关键词： multi-color space k-nearest neighbor algorithm (k-NN) self-learning surge test

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高速单像素成像技术原理及应用 Review

Qiang GUO, Yu-xi WANG, Hong-wei CHEN, Ming-hua CHEN, Si-gang YANG, Shi-zhong XIE

《信息与电子工程前沿（英文）》 2017年第18卷第9期页码 1261-1267 doi: 10.1631/FITEE.1601719

摘要：单像素成像技术具有利用一个单像素探测器获取高分辨图像的能力，近十年来得到广泛关注。该技术已应用于多个领域，如核磁共振成像、航天遥感、太赫兹成像和高光谱成像。与传统相机相比，单像素相机可以实现图像压缩和超宽的频谱工作范围。然而，单像素相机的成像速度受到数字微镜阵列和图像压缩程度限制，导致其时间分辨率较低（毫秒量级）。因此，观察显微成像中的高速动态现象对于单像素相机而言是巨大挑战。最近，基于光子时间拉伸的高速单像素成像技术被提出，其远超普通相机的成像速度也得到验证。本文介绍了光子时间拉伸技术的原理和应用，给出了高速单像素相机的结构，并通过实验证实利用该相机可实现高速和高吞吐量细胞流式分析，最后，讨论了高速单像素相机的局限和应用潜力。

关键词：压缩采样；单像素成像；光子时间拉伸；成像式流式细胞仪

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高等植物叶片色域的理论研究

程晓舫,董金一,范学良,丁金磊

《中国工程科学》 2006年第8卷第12期页码 66-69

摘要：

利用叶绿素和类胡萝卜素的经典吸收光谱以及植物叶片中不含色素的其他物质成分的光谱，分别求得其在CIE1931色品图中的理论坐标，并根据色度学中的加法混色原理确定出高等植物叶色的理论域范围。实验数据与理论相吻合。

关键词：高等植物色素吸收光谱色度坐标色域

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Carbon dots-based fluorescence sensor for two-photon imaging of pH in diabetic mice

《化学科学与工程前沿（英文）》 2023年第17卷第3期页码 298-306 doi: 10.1007/s11705-022-2212-9

摘要： Herein, a reversible pH fluorescent sensor was developed using caffeic acid as the precursor by one-step solvothermal synthesis method. The carbon dots-based sensor (CA-CDs) exhibited pH-dependent increase in fluorescence intensity and showed linear relationship in the range of pH 6.60 and 8.00. Notably, the fluorescence sensor has a reversible response to pH change. Finally, the CA-CDs has been successfully applied for two-photon imaging of the pH in liver and kidney of diabetic mice. Imaging results showed that the pH value in kidney of diabetic mice was lower than that of the normal mice, while the pH value in liver of diabetic mice was almost the same as that of the normal mice. The present study provides a simple analytical method for pH detection suitable for in vivo.

关键词： carbon dots two-photon imaging pH diabetic mice

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In vivo imaging of hematopoietic stem cell development in the zebrafish

Panpan Zhang, Feng Liu

《医学前沿（英文）》 2011年第5卷第3期页码 239-247 doi: 10.1007/s11684-011-0123-0

摘要： imaging is crucial for developmental biology and can further help to follow cell development/differentiation in normal and pathological conditions. Recent advances in optical imaging techniques has facilitated tracing of the developmental dynamics of a specific organ, tissue, or even a single cell. The zebrafish is an excellent model for imaging of hematopoiesis due to its transparent embryo at early stage; moreover, different zebrafish hematopoietic stem cells (HSCs) transgenic lines have been demonstrated as very useful tools for illustrating the details of the HSC developmental process. In this review, we summarize recent studies related to the non-invasive imaging of HSC transgenics, to show that zebrafish transgenic lines are powerful tools for developmental biology and disease. At the end of the review, the perspective and some open questions in this field will be discussed.

关键词： hematopoietic stem cell hematopoiesis in vivo imaging transgenics zebrafish

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光场成像技术：模型、标定、重建及应用 Review

Hao ZHU, Qing WANG, Jingyi YU

《信息与电子工程前沿（英文）》 2017年第18卷第9期页码 1236-1249 doi: 10.1631/FITEE.1601727

摘要：光场成像是计算摄像学领域一项新兴技术。基于对成像模型和光路的创新设计，光场相机不仅记录了三维物体的空间强度，而且捕获了物理世界中的角度信息。这为解决三维重建、显著区域检测、目标识别等计算机视觉问题提供了新途径。本文首先回顾了光场相机的三个关键问题，包括成像模型、标定理论以及重建方法。然后，系统介绍了光场成像技术在信息学、物理学、医学和生物学等领域的应用现状。最后，讨论了光场成像目前存在的问题，并展望了光场成像技术的应用前景。

关键词：光场成像；全光函数；成像模型；标定；重建

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Synthesis and application of superparamagnetic iron oxide nanoparticles in targeted therapy and imaging

Liangqian Tong, Ming Zhao, Shu Zhu, Jing Chen

《医学前沿（英文）》 2011年第5卷第4期页码 379-387 doi: 10.1007/s11684-011-0162-6

摘要： Superparamagnetic iron oxide (SPIO) nanoparticles have become a popular strategy of cancer treatment and molecular imaging because of their versatile properties and biocompatibility. A variety of studies have shown the exciting potential of functionalized SPIO nanoparticles, such as surface-coated, targeted ligand-conjugated, and/or drug-loaded SPIO nanoparticles, as powerful tools for targeted imaging and therapy. Moreover, the applications of SPIO nanoparticles that integrate diagnosis and therapy in SPIO nanoparticles facilitate the monitoring of therapeutic efficacy during treatment. In the present review, we primarily concentrate on the recent advancements in the field of SPIO nanoparticles in terms of synthesis, targeted therapy, and cancer imaging.

关键词： nanoparticles superparamagnetic iron oxide targeted therapy molecular imaging cancer

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A highly selective fluorescent probe for real-time imaging of UDP-glucuronosyltransferase 1A8 in living

《化学科学与工程前沿（英文）》 2022年第16卷第1期页码 103-111 doi: 10.1007/s11705-021-2064-8

摘要： Uridine diphosphate (UDP)-glucuronosyltransferases (UGTs) are enzymes involved in the biotransformation of important endogenous compounds such as steroids, bile acids, and hormones as well as exogenous substances including drugs, environmental toxicants, and carcinogens. Here, a novel fluorescent probe BDMP was developed based on boron-dipyrromethene (BODIPY) with high sensitivity for the detection of UGT1A8. The glucuronidation of BDMP not only exhibited a red-emission wavelength (λ_ex/λ_em = 500/580 nm), but also displayed an excellent UGT1A8-dependent fluorescence signal with a good linear relationship with UGT1A8 concentration. Based on this perfect biocompatibility and cell permeability, BDMP was successfully used to image endogenous UGT1A8 in human cancer cell lines (LoVo and HCT15) in real time. In addition, BDMP could also be used to visualize UGT1A8 in tumor tissues. These results suggested that BDMP is a promising molecular tool for the investigation of UGT1A8-mediated physiological function in humans.

关键词： UDP-glucuronosyltransferase 1A8 fluorescent probe subtype selectivity fluorescence imaging

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of the mechanisms of acupuncture in the treatment of migraine based on functional magnetic resonance imaging

《医学前沿（英文）》页码 993-1005 doi: 10.1007/s11684-023-0989-7

摘要： Migraine is one of the most prevalent and disabling neurological disease, but the current pharmacotherapies show limited efficacy and often accompanied by adverse effects. Acupuncture is a promising complementary therapy, but further clinical evidence is needed. The influence of acupuncture on migraine is not an immediate effect, and its mechanism remains unclear. This study aims to provide further clinical evidence for the anti-migraine effects of acupuncture and explore the mechanism involved. A randomized controlled trial was performed among 10 normal controls and 38 migraineurs. The migraineurs were divided into blank control, sham acupuncture, and acupuncture groups. Patients were subjected to two courses of treatment, and each treatment lasted for 5 days, with an interval of 1 day between the two courses. The effectiveness of treatment was evaluated using pain questionnaire. The functional magnetic resonance imaging (fMRI) data were analyzed for investigating brain changes induced by treatments. Blood plasma was collected for metabolomics and proteomics studies. Correlation and mediation analyses were performed to investigate the interaction between clinical, fMRI and omics changes. Results showed that acupuncture effectively relieved migraine symptoms in a way different from sham acupuncture in terms of curative effect, affected brain regions, and signaling pathways. The anti-migraine mechanism involves a complex network related to the regulation of the response to hypoxic stress, reversal of brain energy imbalance, and regulation of inflammation. The brain regions of migraineurs affected by acupuncture include the lingual gyrus, default mode network, and cerebellum. The effect of acupuncture on patients’ metabolites/proteins may precede that of the brain.

关键词： acupuncture migraine fMRI metabolome proteome