Imaging proteins in vivo using fluorescence lifetime microscopy

Fluorescence lifetime imaging (FLIM) represents a key optical technique for imaging proteins and protein interaction in vivo. We review the principles and recent advances in the application of the technique, instrumentation and molecular probe development.     

小动物活体成像技术的应用

小动物活体成像技术在国内外得到越来越多的普及应用,极大地促进了生命科学特别是肿瘤研究的发展。本文就小动物活体成像技术的原理、标记方法和实际应用做简单介绍。     

Protein microarray biosensors based on imaging ellipsometry techniques and their applications

After years of development, biosensors based on imaging ellipsometry and biosensors based on total internal reflection imaging ellipsometry have been successfully implemented in various engineering systems. Their experimental setups, detection principles, and biological and clinical applications are briefly reviewed.     

多功能磁共振造影剂研究进展

磁共振成像技术因对人体无创、任意方向断层扫描三维图像且分辨率较高、提供形态与功能两方面诊断评价等突出优点,成为了临床上用于疾病诊断的重要手段之一。临床上使用磁共振造影剂可以提高成像的分辨率和灵敏度,提高图像质量,增强对比度和可读性。但是,各种成像技术由于实现原理不同,具有各自的优势和缺陷,靠传统单一的诊断模式无法提供疾病的全面信息,因而在对各种复杂疾病进行诊断时会受到一定的限制。因此,将磁共振成像与其他成像技术如CT成像、超声成像等联合起来使用,则可以达到优势互补的效果,能为疾病的临床诊断提供更快捷精确的信息,同时可将磁共振成像与各种治疗方式结合在一起,即开发基于磁共振成像的诊断治疗一体化试剂,以实现对疾病的即时治疗和实时监控。本文主要介绍了磁共振成像造影剂的原理和种类,并且综述了目前国内外在基于磁共振成像的多功能造影剂/诊疗制剂这一领域的研究进展,最后就未来可能的研究方向进行了展望。     

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.     

Application of optical imaging and spectroscopy to radiation biology

Optical imaging and spectroscopy is a diverse field that has been of critical importance in a wide range of areas in radiation research. It is capable of spanning a wide range of spatial and temporal scales, and has the sensitivity and specificity needed for molecular and functional imaging. This review will describe the basic principles of optical imaging and spectroscopy, highlighting a few relevant applications to radiation research.     

Magnetic Resonance Imaging Part I—Physical Principles

Magnetic resonance (MR) imaging is the most complex imaging technology available to clinicians. Whereas most imaging technologies depict differences in one, or occasionally two, tissue characteristics, MR imaging has five tissue variables—spin density, T₁ and T₂ relaxation times and flow and spectral shifts—from which to construct its images. These variables can be combined in various ways by selecting pulse sequences and pulse times to emphasize any desired combination of tissue characteristics in the image. This selection is determined by the user of the MR system before imaging data are collected. If the selection is not optimal, the imaging process must be repeated at a cost of time and resources.The optimal selection of MR imaging procedures and the proper interpretation of the resultant images require a thorough understanding of the basic principles of MR imaging. Included in this understanding should be at least the rudiments of how an MR imaging signal is produced and why it decays with time; the significance of relaxation constants; the principles of scanning methods such as saturation recovery, inversion recovery and spin echo; how data obtained by these methods are used to form an image, and how the imaging data are complied by multi-slice and volumetric processes. In selecting an MR imaging unit, information about different magnet designs (resistive, superconductive and permanent) is useful. Although no bioeffects are thought to be associated with an MR imaging examination, some knowledge of the attempts to identify bioeffects is helpful in alleviating concern in patients.     

Principles of nuclear medicine imaging: planar, SPECT, PET, multi-modality, and autoradiography systems

The underlying principles of nuclear medicine imaging involve the use of unsealed sources of radioactivity in the form of radiopharmaceuticals. The ionizing radiations that accompany the decay of the administered radioactivity can be quantitatively detected, measured, and imaged in vivo with instruments such as gamma cameras. This paper reviews the design and operating principles, as well as the capabilities and limitations, of instruments used clinically and preclinically for in vivo radionuclide imaging. These include gamma cameras, single-photon emission computed tomography (SPECT) scanners, and positron emission tomography (PET) scanners. The technical basis of autoradiography is reviewed as well.     

Time-lapse imaging of neural development: zebrafish lead the way into the fourth dimension

Time-lapse imaging is often the only way to appreciate fully the many dynamic cell movements critical to neural development. Zebrafish possess many advantages that make them the best vertebrate model organism for live imaging of dynamic development events. This review will discuss technical considerations of time-lapse imaging experiments in zebrafish, describe selected examples of imaging studies in zebrafish that revealed new features or principles of neural development, and consider the promise and challenges of future time-lapse studies of neural development in zebrafish embryos and adults.     

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.     

小动物体内可见光三维成像技术研究进展

活体动物体内可见光成像是采用生物发光和荧光为标记物,利用灵敏的仪器来监控活体动物体内的细胞活动、蛋白表达情况和基因行为。近年来,可见光成像在生物医学的各个方面得到了广泛的应用。随着成像技术和检测仪器的不断发展,现已从平面二维成像逐渐发展为立体三维成像。三维成像技术在靶点的空间定位、与器官的关系,及绝对定量方面都有了很大的进展。本文就三维成像技术的原理、应用和发展前景进行了简要的综述。     

Exploiting the light-metal interaction for biomolecular sensing and imaging

The ability of metal surfaces and nanostructures to localize and enhance optical fields is the primary reason for their application in biosensing and imaging. Local field enhancement boosts the signal-to-noise ratio in measurements and provides the possibility of imaging with resolutions significantly better than the diffraction limit. In fluorescence imaging, local field enhancement leads to improved brightness of molecular emission and to higher detection sensitivity and better discrimination. We review the principles of plasmonic fluorescence enhancement and discuss applications ranging from biosensing to bioimaging.     

Second harmonic generation microscopy: a powerful tool for bio-imaging

Second harmonic generation (SHG) microscopy is an important optical imaging technique in a variety of applications. This article describes the history and physical principles of SHG microscopy and its more advanced variants, as well as their strengths and weaknesses in biomedical applications. It also provides an overview of SHG and advanced SHG imaging in neuroscience and microtubule imaging and how these methods can aid in understanding microtubule formation, structuration, and involvement in neuronal function. Finally, we offer a perspective on the future of these methods and how technological advancements can help make SHG microscopy a more widely adopted imaging technique.     

From medical imaging to image-guided therapy

This survey on medical imaging provides a look into three major components. The first one deals with the full steps through which it must be apprehended: from the sensors to the reconstruction, from the image analysis up to its interpretation. The second aspect describes the physical principles used for imaging (magnetic resonance, acoustic, optics, etc.). The last section shows how imaging is involved in therapeutic procedures and in particular the new physical therapies. All along this paper, the research perspectives are sketched.     

光学相干层析成像技术在内窥镜中的应用

光学相干层析成像(optical coherence tomography,OCT)技术是继X射线成像、核磁共振成像、超声成像等之后的一种新型的成像技术,其可光纤化的特点使得它易于医用电子内窥镜相结合。OCT内窥镜技术可实现对人体内部器官的高速率、高分辨率、无损伤、实时成像。主要介绍了OCT技术的种类、基本原理以及包括探测深度和纵向分辨率等的参数;简述了OCT内窥镜的发展历史以及最新成果,重点分析了光源对OCT内窥镜的影响。总结了OCT内窥镜的主要应用。     

超分辨显微成像技术在活细胞成像中的应用与发展

超分辨显微成像技术(super-resolution microscopy,SRM)可以绕过光学衍射极限对成像分辨率的限制,让以前观察不到的纳米级结构实现可视化,这一重大研究进展推动了现代生命科学和生物医学研究的进步与发展.细胞是生物体的基本组成单位,对活细胞内部的细微结构和动力学过程进行研究是掌握生命本质必不可少的途...     

Neuro at the Nanoscale: Diffraction-Unlimited Imaging with STED Nanoscopy

Recent breakthroughs in fluorescence microscopy have pushed spatial resolution well beyond the classical limit imposed by diffraction. As a result, the field of nanoscopy has emerged, and diffraction-unlimited resolution is becoming increasingly common in biomedical imaging applications. In this review, we recap the principles behind STED nanoscopy that allow imaging beyond the diffraction limit, and highlight both historical and recent advances made in the field of neuroscience as a result of this technology.     

The Applicability of Amide Proton Transfer Imaging in the Nervous System: Focus on Hypoxic-Ischemic Encephalopathy in the Neonate

In recent years, magnetic resonance imaging (MRI) has become more widely used in neonatal hypoxic-ischemic encephalopathy (HIE), involving, for example, evaluation of cerebral edema, white matter fiber bundle tracking, cerebral perfusion status, and assessment of brain metabolites. MRI has many imaging modalities. However, its application for assessing changes in the internal environment at the tissue and cellular level after hypoxia–ischemia remains a challenge and is currently the focus of intense research. Based on the exchange between amide protons of proteins and polypeptides and free water protons, amide proton transfer (APT) imaging can display changes in pH and protein concentrations in vivo. This paper is a review of the principles of APT imaging, with a focus on the potential application of APT imaging for neonatal HIE.     

Recent advances in biological imaging

Recent innovations in microscopy and digital image processing have greatly enhanced the power of biological imaging. Basic principles of several new methods in light and electron microscopy will be discussed, and examples presented of their application to cell and molecular biology.     

基于三通道的超分辨率显微镜成像

显微技术经过快速发展，已经突破了光学衍射极限，目前主要包含受激发射损耗显微术（STED）、结构光照明显微镜（SIM）、光激活定位显微成像（PALM）、随机光学重构显微术（STORM）、基于最少光子数的纳米尺度定位（MINFLUX）、结合结构光照明技术的MINFLUX技术变体（SIMFLUX）等技术。STORM技术具有优越性，在其基础上叠加多色成像技术（目前有6种），本文介绍了目前最新的多色成像技术以及分光成像实现的三通道成像技术。分光成像实现的三通道成像存在光谱串色、通道对齐误差等影响，基于此介绍了相关的优化算法原理。展示了在三通道STORM显微成像平台上实现的COS-7细胞成像。说明三通道STORM显微成像的优越性。