整合荧光成像和化疗的有机小分子诊疗探针的研究进展

将诊断与治疗功能结合为一体是当前应对癌症的一种新兴策略. 诊疗一体化作为一种潜在的新型医学诊治方式, 在快速获得体内信息、 改善生物分布、 减少剂量和降低毒副作用等方面具有潜在的应用前景. 荧光成像被广泛应用于医学诊断, 近年来近红外荧光成像技术得到飞速发展, 在活体成像方面具有较好的穿透深度和成像分辨率. 本文综合评述了部分整合荧光成像和化疗的有机单分子诊疗试剂的相关研究, 并对诊疗一体化探针的未来研究进行了展望.     

成像技术在食品安全与质量控制中的研究进展

食品质量与安全是政府、食品行业以及消费者十分关注的问题。为了保证食品质量与安全，需要对食品中的风险因子进行检测。传统的分析方法如生物化学方法和仪器分析方法（色谱法、色谱-质谱法）存在前处理比较复杂，耗时，对样品具有破坏性及无法获取目标物空间信息等缺点。因此，开发快速，无损，实时和可视化的检测技术十分重要，这也是食品领域研究的热点。近年来，高光谱成像技术融合了成像和光谱两种技术，可以作为一种用于食品质量和安全评估的非破坏性和实时检测的工具。拉曼光谱成像技术可以同时获得待测物的光谱和空间信息，具有快速，无损和低成本等优点，在食品安全评价和质量控制中也得到了成功应用。质谱成像技术不需要标记和染色，即可实现样品组织表面待测物的可视化和高通量分析。它作为一种分子可视化技术，可以获得食品中营养成分及内、外源性有害物质的空间分布信息，在食品领域也表现出良好的应用前景。本文检索了近几年国内外发表的成像技术在食品研究中的相关文献，介绍了高光谱成像技术、拉曼光谱成像技术和质谱成像技术的原理，并综述了它们在食品安全与质量控制中的应用。此外，本文分析和讨论了这几种成像技术的优缺点，并对成像技术在食品领域的发展前景做出了展望。     

高分辨阿达玛变换显微光谱成像系统研究

阿达玛变换(HT)是一种多通道的光谱调制技术,基于这一原理,研制了一种显微光谱成像系统.通过光学设计,除可以获得微小试样(如单个细胞)的光谱以外,还可以对试样进行分光谱成像,得到分辨率为256×256像素的256级灰度图像.通过对两种不同荧光发射波长的CdSe/ZnS量子点进行的分光谱成像测试表明,本系统具有良好的分光谱成像能力,可以对具有复杂光谱的物质针对其某一特定成分进行成像.     

同步辐射红外光谱成像技术对细胞的研究

同步辐射红外显微光谱技术凭借其超高亮度和高空间分辨率的优势,已经在多学科领域中取得了大量的研究成果。特别是在生物医学领域,同步辐射红外显微光谱可以对无染色、无标记的生物样品进行无损检测并可获得生物分子的大量结构信息,因此得到广泛应用。随着同步辐射红外显微光谱技术的发展,生物化学家和光谱学家已经将研究的重点从组织层次的红外光谱成像（组织红外光谱成像）扩展到细胞层次的红外光谱成像（细胞红外光谱成像）,并在近十年的研究中取得了大量的研究成果,但同时也暴露出一些问题,例如（1）细胞或介质中的水在红外光谱酰胺Ⅰ谱带具有很强的吸收;（2）不平整的细胞表面会导致红外光谱中产生Mie散射;（3）细胞红外光谱的复杂性和不确定性会影响数据分析的有效性和准确性。另一方面,生化学家和光谱学家也为解决这些问题采取了许多有用的策略。因此,本综述首先从样品制备、实验设计以及数据分析等方面对最近十年来细胞同步辐射红外光谱成像技术取得的成果进行了总结,随后介绍了目前细胞红外成像技术面临的问题以及解决策略。我们相信,通过多束同步辐射红外光与焦平面阵列（FPA）探测器的结合,同步辐射红外光谱成像技术在对细胞的结构和功能研究中以及其他领域不同材料的研究中都会逐步显示出独特的作用。     

隐身材料红外光谱特性评价方法

对隐身材料光红外谱特性评价方法进行了综述.分别介绍了近红外分光光度计光谱反射率测定方法、热红外成像技术、热红外发射率测定方法以及高光谱成像方法.通过人工绿与自然绿色物体的光谱反射率实验提出了近红外隐身材料与实际地物背景存在的差异及其需要改进的技术.     

同步辐射显微红外光谱法应用于杜仲的研究

同步辐射显微红外光谱具有高亮度、高信噪比等优势.应用同步辐射显微红外光谱对于中药进行研究,可以进行微区分析,从而更加深入了解中药的组成.应用同步辐射显微红外光谱对于杜仲的冰冻切片进行研究,采集不同微区的一系列红外光谱;同时对选定区域进行化学成像,进一步研究该区域中化学组成的分布,从而对于杜仲红外光谱中各个峰的归属有深入...     

面向绘画艺术品复制的多光谱图像数字修复技术研究

绘画艺术品作为人类文明的瑰宝,有着不可估量的艺术价值,然而受人为、意外以及自然环境等因素的影响,会有不同程度的损坏。面向艺术品复制的多光谱图像数字修复,目的是通过采用多光谱技术获取客观准确的艺术品颜色信息并用于彩色图像数字修复,进而用于艺术品的数字典藏、高保真图像复制,满足人们对绘画艺术品颜色准确性与结构完整性的需求。论文研究了多光谱成像技术及其在彩色数字图像修复上的应用,通过多光谱成像系统获取多通道图像,经过图像配准、滤噪、重构与还原,可获得色彩丰富、颜色逼真的多光谱图像,以此作为彩色数字图像进行数字修复,修复质量优于传统获取的RGB图像,取得了较好的修复结果。主要内容： 1.探讨了基于多光谱的绘画艺术品数字修复技术理论框架及面向艺术品复制的需要,对其中的关键问题进行了阐述。基于多光谱成像技术进行图像的获取满足高保真复制对颜色准确性与结构完整性的需求,探讨了其中涉及的关键技术。 2.分析了多光谱图像在颜色复制、图像高保真复制要求方面的优势,探讨了光谱成像的原理,对基于训练样本的多通道图像光谱重构技术进行了研究,提出了针对非线性成像系统基于主成份和多项式回归法的光谱重构算法,对光谱重构精度和色度精度有一定的改善。 3.分析了光谱反射率重构过程中传统训练样本对样本选择的局限性——不能综合反映颜色的光谱特性和色度特性,训练样本的相似性较差。提出基于光谱反射率空间相关性最小以及色度空间相似性聚类的训练样本选择方法,综合考虑了样本的光谱特性和色度特性,实验结果表明,光谱重构精度有一定改善。 4.对面向高保真图像复制的有破损绘画艺术品图像修复问题进行了分析,从3个方面分析了彩色图像的数字修复方法,并针对彩色图像修复时带来的伪彩现象提出了优化方法,提出了基于图像分解的改进算法和彩色图像修复流程,实验结果表明,图像修复的结果明显有所改善,修复图像的均方误差、峰值信噪比和结构相似度统计评价指标明显提高,适合于面向绘画艺术品高保真图像复制的数字修复,为多光谱图像修复奠定了基础。     

多光谱光声层析成像及其在生物医学中的应用

多光谱光声层析成像(MSOT)技术是一种将多光谱成像与光声层析成像(PACT)技术相结合的新技术,该技术利用不同生物组织的光谱吸收特性,用多组不同波长的短脉冲激光照射组织以产生组织特异性的光声信号,从而更好地进行光声成像和组分识别。MSOT兼具光学成像的高灵敏度、高分辨率优势和超声成像可对数厘米深组织成像的长处,同时又能弥补光学成像深度有限和超声成像对比度差的短处,能够实现深层组织的高分辨率、高对比度、高穿透深度的实时无损伤成像。迄今为止,MSOT已应用于肿瘤内光吸收粒子的检测、血管结构和血液氧合作用的评价、生物荧光蛋白的成像以及乳腺癌患者检测的初步研究。随着光声成像系统的不断改进,MSOT与生物标记物(如荧光试剂、金纳米颗粒等)结合对体内分子进行成像,在生物医学中得到了广泛的应用。本文简要综述了MOST的成像原理、实验装置及其性能特点,着重总结了其在生物医学领域的最新应用进展,尤其是在新生血管成像、肿瘤的早期诊断及肿瘤的原位成像方面。     

质谱成像技术在肿瘤研究中的应用进展

质谱成像(Mass spectrometry imaging,MSI)作为一种新型的分子成像技术,具有无需标记、无需复杂样品前处理、高通量等优点,可实现脂类、代谢物等的直接分析,并可获得组织切片中物质的空间分布信息,已成为生物、医学等领域研究的有力工具。离子化技术是质谱成像的关键和核心,新型质谱成像离子化技术的不断涌现,推动了质谱成像技术在肿瘤研究中的应用。该文着重介绍了当前主要质谱成像技术的原理及特点,并对其在肿瘤的病理诊断、标志物、药物研究等方面的应用进行评述,为质谱成像技术在肿瘤方面的研究提供参考。     

基于高光谱和化学计量学方法的除草剂残留分类识别研究

本研究基于高光谱技术和化学计量学方法,对薄荷叶上的异丙甲草胺、烟嘧(莠去津、敌草胺和砜嘧(精喹4类除草剂残留进行种类判别.高光谱成像光谱范围为450nm～950nm的可见-近红外区域.为降低噪音对光谱数据的干扰、提升判别精度,采用SG平滑和多元散射校正对高光谱曲线进行处理.利用主成分分析算法(PCA)对原始数据进行降维...     

Label‐Free Molecular Imaging of Biological Cells and Tissues by Linear and Nonlinear Raman Spectroscopic Approaches

Raman spectroscopy is an emerging technique in bioanalysis and imaging of biomaterials owing to its unique capability of generating spectroscopic fingerprints. Imaging cells and tissues by Raman microspectroscopy represents a nondestructive and label‐free approach. All components of cells or tissues contribute to the Raman signals, giving rise to complex spectral signatures. Resonance Raman scattering and surface‐enhanced Raman scattering can be used to enhance the signals and reduce the spectral complexity. Raman‐active labels can be introduced to increase specificity and multimodality. In addition, nonlinear coherent Raman scattering methods offer higher sensitivities, which enable the rapid imaging of larger sampling areas. Finally, fiber‐based imaging techniques pave the way towards in vivo applications of Raman spectroscopy. This Review summarizes the basic principles behind medical Raman imaging and its progress since 2012.     

Quantitative analysis in medicine using photoacoustic tomography

Photoacoustic imaging, or photoacoustic tomography, is a 2D or 3D optical imaging method based on localized optical absorption of pulsed laser radiation. By a spatially resolved detection of the following thermoelastic expansion, the local distribution of the absorption can be determined. The technique has been proven to have significant potential for the imaging of human and animal organs and single blood vessels, combining high contrast with good spatial resolution. The contrast is based on the specific optical absorption of certain components in the visible and near-infrared spectral range, for most applications of blood. Generally, the images represent the local distribution of blood in a qualitative or semiquantitative way. Although photoacoustic imaging is capable of revealing absolute and spatially resolved concentrations of endogenous (such as oxyhemoglobin and deoxyhemoglobin) or artificial (such as tumor markers) chromophores, only a very limited number of publications have dealt with this demanding task. In this report, the problems involved and possible solutions are reviewed and summarized.     

Recent advances in AIEgens for three-photon fluorescence bioimaging

Bioimaging is increasingly becoming an indispensable tool in disease diagnosis, clinical trials and medical practice. Fluorescence bioimaging is minimally invasive, affordable and portable, with the potential to become a widespread medical imaging technique. Currently, a serious challenge obstructing the large-scale clinical applications of fluorescence technique is the shallow penetration depth. Three-photon fluorescence offers several advantages over near-infrared and two-photon fluorescence, such as deeper penetration, more confined excitation areas and higher resolution. On the other hand, fluorophores displaying solid-state fluorescence are intriguing because they can emit bright fluorescence in the condensed phase, which is beneficial to imaging applications demanding intense emission signals. This review highlights the recent advances in small organic AIEgens for three-photon fluorescence bioimaging in vivo. The progress suggests that three-photon fluorescence imaging offers deep penetration, good photostablity and high signal-to-background contrast, which is valuable in fluorescence imaging in vivo.     

Multivariate data analysis for Raman imaging of a model pharmaceutical tablet

Spectroscopic imaging techniques provide spatial and spectral information about a sample simultaneously and are finding ever-increasing application in the pharmaceutical industry. Effective extraction of chemical information from imaging data sets is a crucial step during the application of imaging techniques. Multivariate imaging data analysis methods have been reported but few applications of these methods for pharmaceutical samples have been demonstrated. In this study, a bilayer model tablet consisting of avicel, lactose, sodium benzoate, magnesium stearate and red dye was prepared using custom press tooling, and Raman mapping data were collected from a 400 μm × 400 μm area of the tablet surface. Several representative multivariate methods were selected and used in the analysis of the data. Multivariate data analysis methods investigated include principal component analysis (PCA), cluster analysis, direct classical least squares (DCLS) and multivariate curve resolution (MCR). The relative merits and drawbacks of each technique for this application were evaluated. In addition, some practical issues associated with the use of these methods were addressed including data preprocessing, determination of the optimal number of clusters in cluster analysis and the optimization of window size in second derivative calculation.     

Detection of colonic malignant lesions by digital imaging of UV laser-induced autofluorescence

The objective of our study was to investigate whether digital imaging of autofluorescence could be applied in the detection of colonic malignancies. Autofluorescence was excited with a 325 nm line from a He-Cd laser. Images were recorded in vitro in six spectral bands. The material for study was 50 resected specimens for which images of 64 areas were recorded. The main result is the observation that for a majority of malignant and premalignant lesions the intensity of autofluorescence was lower than for the corresponding normal mucosa in all of the spectral bands selected for imaging. The spectral bands centered around 440 nm and 475 nm seem to be most promising in terms of possible future clinical applications.     

Visible and near-infrared chemical imaging methods for the analysis of selected forensic samples

This study investigated various chemical imaging methods for the forensic analysis of paints, tapes and adhesives, inks and firearm propellants (absorption and photoluminescence in the UV-vis-NIR regions). Results obtained using chemical imaging technology were compared with those obtained using traditional techniques. The results show that chemical imaging offers significant advantages in the forensic context, for example the ability to display visual and spectral results side by side and to reduce sample preparation, hence minimizing the risk of contamination. Chemical imaging produced a greater discriminating power than traditional techniques for most evidence types. Chemical imaging also eliminated different brands of ammunition based on the fluorescence characteristics of the propellant grains preserving the evidence for further analysis. It is expected that this technology will find broader forensic applications in the future.     

自适应拉曼光谱成像数据去噪及其在植物细胞壁光谱分析中的应用

拉曼光谱成像数据存在基线漂移与宇宙射线干扰峰两类噪声信号,无法直接用于光谱分析研究,必须去除。现有单光谱去噪方法处理结果不稳定、可重复性差。针对这一问题,本研究提出了一种自适应拉曼光谱成像数据新型去噪法,采用优化的自适应迭代惩罚最小二乘法( Adaptive iteratively reweighted penalized least-squares,airPLS)和基于主成分分析( PCA)的干扰峰消除算法修正光谱基线漂移和宇宙射线干扰峰,具有输入参数少、光谱失真小、处理速度快、去噪结果稳定等优点。利用本方法去除了芒草( Miscanthus sinensis)细胞壁拉曼光谱成像数据(9010条光谱)中的噪声信号,并对去噪后数据进行PCA和聚类分析(CA),成功区分非植物光谱与植物光谱,分类结果优于未去噪数据。预期本方法可应用于其它光谱成像数据去噪,为光谱的解译和定量分析提供可靠的研究基础。     

Reverse detection for spectral width improvements in spatially encoded dimensions of ultrafast two‐dimensional NMR spectra

Recently, the spatially encoded technique has been broadly used in the fast analyses of chemical systems and real‐time detections of chemical reactions. In spatially encoded ultrafast 2D spectra, spectral widths and resolution in spatially encoded dimensions are contradictive, leading to the risk of insufficient spectral widths when providing satisfactory resolution values for all resonances. Here, a method named as reverse detection is proposed to improve the spectral width in the spatially encoded dimension. Experimental results show that spectral width improvements are at least twofold with reverse detection solely, and more improvements can be expected along with the gradient‐controlled folding method. The proposed method can be applied to almost any spatially encoded scheme with echo planar spectroscopic imaging—like detection module and may promote wide applications of ultrafast 2D spectroscopy techniques in chemical analyses. Copyright © 2014 John Wiley & Sons, Ltd.     

Biological applications of scanning electrochemical microscopy: chemical imaging of single living cells and beyond

Recent applications of scanning electrochemical microscopy (SECM) to studies of single biological cells are reviewed. This scanning probe microscopic technique allows the imaging of an individual cell on the basis of not only its surface topography but also such cellular activities as photosynthesis, respiration, electron transfer, single vesicular exocytosis and membrane transport. The operational principles of SECM are also introduced in the context of these biological applications. Recent progress in techniques for high-resolution SECM imaging are also reviewed. Future directions, such as single-channel detection by SECM, high-resolution imaging with nanometer-sized probes, and combined SECM techniques for multidimensional imaging are also discussed.