多光谱成像技术在植物学研究中的应用

多光谱成像(MSI)技术是一种新兴的成像检测技术, 通过将光谱与成像合二为一, 可实现植物结构、生理、生化表型的定性定量分析及其特征分布的评估。近年来, 与数学建模分析结合的MSI技术具有强大的信息捕获能力, 在植物学研究中展现出强劲的应用潜力。该文介绍了MSI技术的成像原理, 总结了近年来MSI技术在植物损伤鉴定、病害研究、代谢物质生化特征及生理进程鉴定方面的应用, 展望了该技术在植物研究领域的前沿性发展, 以期使MSI技术在植物研究中得到更好的应用。     

高光谱成像技术在生物医学中的应用

高光谱成像技术是传统成像与光谱技术相结合的一门新技术,其可同时获得被测物体的空间特征与光谱信息,以实现对物质特性的研究。本文介绍了高光谱成像技术的基本原理、系统的基本构成及特点,总结和阐述了近年来高光谱成像技术在生物医学领域的发展,以及其在疾病诊断中的应用。     

光声结构与功能成像技术研究进展

光声成像技术利用短脉冲激光激发产生光声信号,可重建出组织的光吸收分布图像,它结合了纯光学成像的高对比度和纯声学成像的高分辨率特性.光声成像技术不仅能够有效的刻画生物组织结构,还能够精确实现无损功能成像,为研究生物组织的形态结构,生理、病理特征,代谢功能等提供了全新手段.本文简要分析了光声信号产生的机理,总结报道了目前实验室几套典型的成像系统及其最新应用进展,指出光声成像作为一种新型的生物医学成像方法,可望引发生物医学影像领域的一次革新.     

电阻抗断层成像技术进展

电阻抗断层成像技术分为:静态EIT(以电阻抗分布的绝对值为成像目标)和动态EIT(以电阻抗分布的相对值为成像目标),它是近年来国内外生物医学工程研究的比较热门的一种成像技术。因为与已有的X射线成像、计算机断层扫描成像(CT)、核磁共振成像(MRI)及超声成像相比,这种新的成像技术不仅具有解剖学的特征信息,还有功能性成像的性质。又因为它的无创、简单、便宜、容易应用等特点,在临床有着很好的应用前景。本文通过数学、物理以及应用上的论述并结合了最新的国内外科研动态。介绍了电阻抗断层成像技术的数学计算(包括算法和算法分析),物理基础(激励方式,激励频率,驱动模式),揭示了电阻抗断层成像技术的基本原理,并展示了此项技术的临床应用情况。     

光声成像造影剂的研究进展

光声成像(PAT)是利用光声效应获得生物组织或材料的断层图像或三维立体图像的一种成像方法,它兼具光学和声学成像的优点,从而成为目前比较有应用前景的一种成像模式。光声成像造影剂是光声成像的对比增强剂,它通过改变局部组织的声学和光学特性,提高成像对比度和分辨率,从而显著增强光声成像的成像效果,成为当前生物医学领域研究的一个热点。目前常见的光声成像造影剂主要有金纳米材料,碳纳米材料,染料相关纳米材料以及其他纳米材料,这些材料有它们独特的优势,它们尺寸小,稳定性好,具有良好的生物相容性,但在临床应用时本身又存在一些问题。本文综述了光声成像造影剂的种类并简要概述了其研究进展,并对其未来在生物医学领域的应用前景做了进一步展望。     

热声成像技术及其在生物医学中的研究进展

摘要：成像技术在疾病的诊断、治疗和监测中起着重要的作用。热声成像作为一种非电离和非侵入性的新型生物医学成像技术,结合了微波成像高对比度和超声成像高分辨率的优点。因其具有利用内源性对比剂（如水和离子）或多种外源性对比剂（或两者兼有）提供结构、功能、和分子信息的能力,在预临床和临床应用中显示出了巨大的潜力。近几十年来,由于微波辐射源和超声硬件的不断发展,热声成像技术已被广泛用于生物医学成像领域。本文阐述了热声成像的基本原理及成像特点,介绍了近年来热声成像技术在生物医学上的应用、当前在解决相应临床问题应用中的优势及研究现状,最后针对热声成像技术在现有生物医学中面临的挑战对该技术进行了展望。     

鼻咽癌细胞组织与血液的SERS光谱研究进展

基于表面增强拉曼光谱(SERS)技术对于人体细胞组织与血液的检测和研究,SERS光谱技术能够发现正常组织与病变组织的差异性,为医学临床上实现癌症的早期诊断提供了科学依据。由于鼻咽癌不具有明显的病变特征、病灶的位置难以通过常规医学手段检测。因此利用SERS光谱技术,应用于鼻咽癌细胞组织与血液的研究,可提高鼻咽癌患者的生存率。对鼻咽癌细胞组织与血液SERS光谱分析和诊断的探索研究,有助于SERS光谱技术发展成为一种在生物医学领域中的分析检测手段,在医学临床诊断上具有潜在的应用前景。     

可检测脑不同部位功能的新医学图像仪MSI

美国加里福尼亚Scripps研究所和新墨西哥大学医学院及退伍军人管理局医学中心合研制成一种新的医学成像像技术—磁源成像(Magnetic Source Imaging,MSI)系统。MSI是一种追踪人体内微弱的生物电信号的技术。无论是脑还是肌肉组织在正常动时都会发出电信号。例如,当一位接受MSI检查的患者动一个手指,他头上的MSI探测器就能测出脑部发出的导致该动作的电信号。与现在所有检测技术不同的是,MSI扫描图不仅能显示脑的结构,尚能标明脑的不同部位的功能。而计算机x线断层(CT)或磁共振     

生物热应变成像技术的研究进展

热应变成像(thermal strain imaging,TSI)是一种利用超声回波时移的温度相关性进行成像的超声应用.它既具有超声安全、无创和实时成像的优点,又能够显示与其他超声成像方式不同的组织特征,具有良好的应用前景.热应变成像目前在生物医学领域主要应用于组织表征和温度监测两个方面.本综述介绍了热应变成像的基本原理,讨论了适用于临床的主要能量源,并通过回顾近几年热应变成像的研究成果和分析目前面临的局限与挑战,对热应变成像技术的发展进行了探讨和展望.     

光声成像及其在生物医学中的应用

光声成像是一种新近迅速发展起来、基于生物组织内部光学吸收差异、以超声作媒介的无损生物光子成像方法,它结合了纯光学成像的高对比度特性和纯超声成像的高穿透深度特性的优点,以超声探测器探测光声波代替光学成像中的光子检测,从原理上避开了光学散射的影响,可以提供高对比度和高分辨率的组织影像,为研究生物组织的结构形态、生理特征、代谢功能、病理特征等提供了重要手段,在生物医学临床诊断以及在体组织结构和功能成像领域具有广泛的应用前景.对光声成像技术的机理、光声成像技术和方法、光声图像重建算法以及光声成像在生物医学上的应用情况作一个简单介绍,希望有助于推动我国在该领域的科研和开发应用工作的迅速发展.     

Multispectral imaging in biology and medicine: slices of life.

Multispectral imaging (MSI) is currently in a period of transition from its role as an exotic technique to its being offered in one form or another by all the major microscopy manufacturers. This is because it provides solutions to some of the major challenges in fluorescence-based imaging, namely ameliorating the consequences of the presence of autofluorescence and the need to easily accommodate relatively high levels of signal multiplexing. MSI, which spectrally characterizes and computationally eliminates autofluorescence, enhances the signal-to-background dramatically, revealing otherwise obscured targets. While this article concentrates on examples derived from liquid-crystal tunable filter-based technology, the intent is to showcase the advantages of multispectral imaging in general. Some technologies used to generate multispectral images are compatible with only particular optical configurations, such as point-scanning laser confocal microscopy. Band-sequential approaches, such as those afforded by liquid-crystal tunable filters (LCTFs), can be conveniently coupled with a variety of imaging modalities, which, in addition to fluorescence microscopy, include brightfield (nonfluorescent) microscopy as well as small-animal, noninvasive in-vivo imaging. Brightfield microscopy is the chosen format for histopathology, which relies on immunohistochemistry to provide molecularly resolved clinical information. However, in contrast to fluorescent labels, multiple chromogens, if they spatially overlap, are much harder to separate and quantitate, unless MSI approaches are used. In-vivo imaging is a rapidly growing field with applications in basic biology, drug discovery, and clinical medicine. The sensitivity of fluorescence-based in-vivo imaging, as with fluorescence microscopy, can be limited by the presence of significant autofluorescence, a limitation which can be overcome through the utilization of MSI.     

Molecular mass spectrometry imaging in biomedical and life science research

This review describes the current state of mass spectrometry imaging (MSI) in life sciences. A brief overview of mass spectrometry principles is presented followed by a thorough introduction to the MSI workflows, principles and areas of application. Three major desorption-ionization techniques used in MSI, namely, secondary ion mass spectrometry (SIMS), matrix-assisted laser desorption ionization (MALDI), and desorption electrospray ionization (DESI) are described, and biomedical and life science imaging applications of each ionization technique are reviewed. A separate section is devoted to data handling and current challenges and future perspectives are briefly discussed at the end.     

In situ metabolomic mass spectrometry imaging: recent advances and difficulties

MS imaging (MSI) is a remarkable new technology that enables us to determine the distribution of biological molecules present in tissue sections by direct ionization and detection. This technique is now widely used for in situ imaging of endogenous or exogenous molecules such as proteins, lipids, drugs and their metabolites, and it is a potential tool for pathological analysis and the investigation of disease mechanisms. MSI is also thought to be a technique that could be used for biomarker discovery with spatial information. The application of MSI to the study of endogenous metabolites has received considerable attention because metabolites are the result of the interactions of a system's genome with its environment and a total set of these metabolites more closely represents the phenotype of an organism under a given set of conditions. Recent studies have suggested the importance of in situ metabolite imaging in biological discovery and biomedical applications, but several issues regarding the technical application limits of MSI still remained to be resolved. In this review, we describe the capabilities of the latest MSI techniques for the imaging of endogenous metabolites in biological samples, and also discuss the technical problems and new challenges that need to be addressed for effective and widespread application of MSI in both preclinical and clinical settings.     

普鲁士蓝纳米粒子在生物医学诊断和治疗中的应用及进展

随着生物医学诊断和治疗的持续深入研究,出现了多种医学诊断和治疗新方法,为人类的健康提供了更大的保证,其中纳米生物技术在生物医学诊断和治疗中的应用日益增多,基于纳米技术,开发传统材料的生物医学新应用成为了人们的研究热点。普鲁士蓝是一种历史悠久的蓝色染料,其制备过程简单、绿色、成本低,化学结构稳定,具有优良的物理、化学、光学以及磁性等性能,已经在许多领域得到了广泛的应用。近年来,普鲁士蓝开始在生物医学诊断和治疗领域中崭露头角,它已经成功的被开发为新型的核磁共振造影剂和光声成像造影剂,并且在药物输送系统和光热治疗等领域也开始占有一席之地,开发基于纳米技术的普鲁士蓝的生物医学应用已经成为极具吸引力的研究方向。本文对普鲁士蓝在生物医学诊断和治疗中的应用及进展进行综述。     

Mass spectrometry imaging and profiling of single cells

Mass spectrometry imaging and profiling of individual cells and subcellular structures provide unique analytical capabilities for biological and biomedical research, including determination of the biochemical heterogeneity of cellular populations and intracellular localization of pharmaceuticals. Two mass spectrometry technologies-secondary ion mass spectrometry (SIMS) and matrix assisted laser desorption/ionization mass spectrometry (MALDI MS)-are most often used in micro-bioanalytical investigations. Recent advances in ion probe technologies have increased the dynamic range and sensitivity of analyte detection by SIMS, allowing two- and three-dimensional localization of analytes in a variety of cells. SIMS operating in the mass spectrometry imaging (MSI) mode can routinely reach spatial resolutions at the submicron level; therefore, it is frequently used in studies of the chemical composition of subcellular structures. MALDI MS offers a large mass range and high sensitivity of analyte detection. It has been successfully applied in a variety of single-cell and organelle profiling studies. Innovative instrumentation such as scanning microprobe MALDI and mass microscope spectrometers enables new subcellular MSI measurements. Other approaches for MS-based chemical imaging and profiling include those based on near-field laser ablation and inductively-coupled plasma MS analysis, which offer complementary capabilities for subcellular chemical imaging and profiling.     

An Instruction on the In Vivo Shell-Less Chorioallantoic Membrane 3-Dimensional Tumor Spheroid Model

The traditional shell chicken chorioallantoic membrane (CAM) model has been used extensively in cancer research to study tumor growth and angiogenesis. Here we present a combined in vivo tumor spheroid and shell-less CAM three-dimensional model for use in quantitative and qualitative analysis. With this model, the angiogenic and tumorigenic environments can be generated locally without exogenous growth factors. This physiological model offers a stable, static and flat environment that features a large working area and wider field of view useful for imaging and biomedical engineering applications. The short experimental time frame allows for rapid data acquisition, screening and validation of biomedical devices. The method and application of this shell-less model are discussed in detail, providing a useful tool for biomedical engineering research.     

生物正交化学在活体标记及药物传递中的研究进展

生物正交化学反应是一类可以在生理条件下发生的化学反应,具有简单、高效、高特异性的特点,在生物医学的研究中被广泛应用.基于生物体天然生命过程的代谢工程,可对生物分子进行无损、高效的生物代谢修饰,是一种理想的生物修饰技术.通过生物代谢途径可有效地将各种化学报告基团引入靶标物的生物分子中,有利于携带配对基团的标记物与其发生生物正交反应,从而在活体系统中实现生物分子的标记示踪和药物递送.这种基于代谢工程与生物正交化学的标记策略因为具有两者之间的优势,在生物医学工程中的标记、成像示踪、诊断等领域展现出巨大的研究价值与应用潜力.本文介绍了生物正交和代谢工程的原理与生物医学研究进展,阐述了生物正交化学在分子成像和药物传递等方面的研究与应用.     

Multispectral near infrared absorption imaging for histology of skin cancer

Multispectral imaging combines the spectral resolution of spectroscopy with the spatial resolution of imaging and is therefore very useful for biomedical applications. Currently, histological diagnostics use mainly stainings with standard dyes (eg, hematoxylin + eosin) to identify tumors. This method is not applicable in vivo and provides low amounts of chemical information. Biomolecules absorb near infrared light (NIR, 800‐1700 nm) at different wavelengths, which could be used to fingerprint tissue. Here, we built a NIR multispectral absorption imaging setup to study skin tissue samples. NIR light (900‐1500 nm) was used for homogenous wide‐field transmission illumination and detected by a cooled InGaAs camera. In this setup, images I(x, y, λ) from dermatological samples (melanoma, nodular basal‐cell carcinoma, squamous‐cell carcinoma) were acquired to distinguish healthy from diseased tissue regions. In summary, we show the potential of multispectral NIR imaging for cancer diagnostics.      

Mass spectrometry imaging for drug distribution studies

Since its introduction mass spectrometry imaging (MSI) has proven to be a powerful tool for the localization of molecules in biological tissues. In drug discovery and development, understanding the distribution of both drug and its metabolites is of critical importance. Traditional methods suffer from a lack of spatial information (tissue extraction followed by LCMS) or lack of specificity resulting in the inability to resolve parent drug from its metabolites (whole body autoradiography). MSI is a sensitive and label-free approach for imaging drugs and metabolites in tissues. In this article we review the different MSI technologies that have been applied to the imaging of pharmaceuticals. Recent technical advances, applications and current analytical limitations are discussed.     

FPGA技术在生物医学成像中的研究进展

数字图像处理技术和微电子集成电路的飞速发展,使实时动态生物医学成像成为可能.生物医学动态成像的关键是高的通讯带宽和快速的数据处理能力,FPGA (field programmable gate array)即现场可编程逻辑门阵列,为数字图像实时处理系统在算法、系统结构上提供了新的思路与方法.文中首先简单介绍FPGA的概念、特点及其发展历程,详细对比FPGA与通用处理器之间的性能指标,然后重点介绍常规生物医疗成像技术原理和FPGA在医疗领域高速成像技术方面的研究和应用情况,最后对FPGA在实时成像方面进行总结和展望.