先进成像技术在全固态锂电池关键问题研究中的应用

全固态锂电池因其高能量密度和安全性良好而备受关注. 然而,要提高其充放电效率和延长其使用寿命需要其在固态电极、固态电解质及两者间的界面实现快速离子传导. 另外,全固态锂电池中的固态电解质隔膜需要限制锂枝晶的生长,从而使得应用高能量密度的锂金属负极变为可能. 本文基于上述全固态锂电池中的重要问题,讨论了电子显微镜、扫描探针显微镜、X射线断层摄影术、磁共振成像和光学显微镜五种先进成像技术在其中的应用.     

X射线成像技术在能源材料研究中的应用

随着人类对可持续能源的需求不断增长,先进的表征方法在能源材料研究等领域变得越来越重要。借助X射线成像技术,我们可以从二维和三维角度实时获取能源材料的形貌、结构和应力变化信息。此外,借助高穿透性X射线和高亮度同步辐射源,设计原位实验,可以获取充放电过程中样品的定性和定量变化信息。本文综述了基于同步加速器的X射线成像技术及其相关应用,讨论了包括X射线投影成像、透射式X射线显微成像、扫描透射X射线显微成像、X射线荧光显微成像以及相干衍射成像等几种主要的X射线成像技术在能源材料研究领域的应用,展望了未来X射线成像的应用前景及发展方向。     

短波近红外在体荧光分子成像技术最新进展

癌症的诊断迄今所依赖的主要是一些离体检测方法以及超声波、X射线透视、X射线CT、核磁共振成像和PET等影像学技术. 癌症的确诊则以肿瘤组织或病变细胞的形态和其它宏观特征为依据, 这往往是一个侵入性和耗时的过程, 不适于癌症的早期诊断. 这些影像学技术目前也大都难以发现分子水平上的问题. 因此, 迄今癌症的早期诊断仍然是医学界面临的一个空前挑战. 光学成像方法, 特别是荧光成像方法具有对人体无害、非侵入、高灵敏和可进行在体多目标成像的优点, 随着荧光指示物的不断拓展和检测方法的不断创新, 有望在分子和细胞水平上实现癌症的早期诊断. 本文重点介绍了几项有较重要价值及工作在短波近红外区域的在体荧光成像技术的新进展.     

同步辐射在分子自组装研究中的应用

同步辐射是一种高亮度、高准直性、宽频谱的优质光源,其在物质原子或分子尺度的结构表征方面具有独特的优势。本文介绍了同步辐射在分子自组装研究中的一些应用,主要包括同步辐射X射线散射、时间分辨的小角X射线散射、时间分辨的X射线衍射、X射线精细结构谱,以及红外光谱,详细阐述了同步辐射X射线散射在层状结构、管状结构以及溶液中的组装体结构表征方面的应用。     

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。     

同步辐射及相关核分析技术在纳米材料生物效应研究中的应用

伴随纳米技术的发展,纳米材料的生物效应研究成为热点,然而这一新兴的研究领域对传统的研究方法提出了挑战,其深入研究有赖于方法学的发展。同步辐射是具有高亮度、高准直、宽频谱等优异性质的光源,其在元素分析及物质原子或分子尺度的结构表征方面具有独特的优势。本文介绍了同步辐射及相关核分析技术,主要包括同步辐射X荧光分析、同步辐射X射线吸收光谱(扩展X射线吸收精细结构EXAFS,X射线吸收近边结构XANES)、同步辐射圆二色谱、电感耦合等离子体质谱、中子活化分析、同位素示踪技术等在纳米生物效应研究中的应用,结合本实验室以及国内外的研究工作详细阐述了基于同步辐射以及相关核分析方法应用于纳米材料表征及其在生物体内的定量、分布、结构分析等方面的最新进展。     

同步辐射红外显微光谱学和成像技术在分析化学中的应用

同步辐射红外显微光谱作为一种新兴的分析技术,一方面利用了红外光谱可以同时表征有机和/或无机、结晶和/或无定形样品的特点,另一方面充分发挥了同步辐射高亮度和高空间分辨率的特性,因此在对小样品或小样品区域的表征上具有传统红外光谱无法比拟的优势。经过20多年的发展,同步辐射红外显微光谱技术已被广泛地应用于多种分析化学领域并取得了丰硕的研究成果。本文总结了最近几年同步辐射红外显微光谱学和成像技术在文化遗产和考古学、地球和空间科学以及化学和高分子科学中的研究和应用进展。     

基于功能核酸的细胞荧光成像

细胞是生物体基本的结构和功能单元,对活细胞中特定生物组分进行动态分析,将为相关生命活动过程的研究提供重要信息。荧光成像为细胞分析提供了一种操作简单、灵敏度高、可实时监测细胞微观动态分子过程的光学生物成像技术。发展高性能的荧光探针用于活细胞成像已成为研究热点。功能核酸是一类具有特殊化学和生物学功能的寡核苷酸分子,除了天然存在的核酶(Ribozyme)和核糖开关(Riboswitch)之外,还包括通过指数富集的配体系统进化技术(SELEX)筛选获得的核酸适体和脱氧核酶(DNAzyme)。功能核酸由于具有合成简单、免疫原性低、相对分子质量小、化学稳定性高、易于修饰等优点,在生物成像领域受到广泛关注。本文主要综述了基于功能核酸的荧光探针在细胞成像领域中的应用研究,总结了该领域面临的挑战,并对其未来发展方向进行了展望。     

同步辐射小角和广角X射线散射在高分子材料研究中的应用

同步辐射X射线散射是研究高分子材料不可替代的重要工具。第三代同步辐射光源—上海光源的成功建设,标志着我国进入国际先进光源俱乐部,为我国高分子材料研究大发展提供了一个契机。本文结合作者和国内外同行的工作,以具体案例的形式介绍了同步辐射小角和广角X射线散射在高分子材料研究中的一些应用,阐述了同步辐射高亮度原位在线研究高分子材料结构形成和演化动力学以及结构与性能关系的独特优势。同时介绍几种自主研制的原位装置和常用的X射线散射数据处理方法。希望本文能起到抛砖引玉的作用,吸引更多的高分子研究同行利用同步辐射开展研究。     

单分子定位超分辨显微成像有机荧光探针的研究进展

在生物医学领域,对纳米尺寸级别的微小生物目标进行精确定位研究具有非常重要的意义,而光学显微成像技术为此提供了强有力的工具。 光学显微成像技术受到光学衍射极限的限制,难以分辨尺寸在衍射极限(<200 nm)以下的生物结构,无法直接获取微小生物结构信息,阻碍了生物医学的进一步发展。 近年来,随着纳米分辨显微成像技术的出现,新型荧光探针的开发、成像系统与设备的不断发展及成像算法不断完善地深入结合,促进了光学衍射极限以下尺寸微观目标的研究。 基于单分子定位的超分辨荧光显微成像(SMLM)包括光激活定位成像(PALM)与随机光学重构超分辨成像(STORM),将有机荧光探针与超分辨光学显微成像技术紧密结合在一起,荧光探针的光物理性质直接决定着超分辨成像结果的好坏。 因此,设计不同性能的荧光探针可以实现超精细结构的不同超分辨成像,为研究其生物学功能提供了有力的工具。 本文着重围绕基于SMLM的原理、有机荧光探针的设计要求、用于SMLM的荧光探针种类及其生物应用等方面进行总结综述,指出了单分子定位成像上存在的不足,并对其发展方向进行了展望,希望为对超分辨成像研究感兴趣或初涉该领域的研究者提供成像理论与探针设计方面的帮助。     

磁共振/光学双模态分子探针的研究现状与展望

基于磁共振与荧光成像的双模态成像技术不仅克服了传统单一分子影像技术在灵敏度、特异度、分辨率等方面的固有缺陷，更是拓宽了分子影像技术在诊断及治疗监控等领域的研究范围及应用前景。本文将对磁共振/荧光双模态分子探针的应用情况和研究进展等进行综述。     

Applications of synchrotron-based X-ray techniques in environmental science

Synchrotron-based X-ray techniques have been widely applied to the fields of environmental science due to their element-specific and nondestructive properties and unique spectral and spatial resolution advantages. The techniques are capable of in situ investigating chemical speciation, microstructure and mapping of elements in question at the molecular or nanometer scale, and thus provide direct evidence for reaction mechanisms for various environmental processes. In this contribution, the applications of three types of the techniques commonly used in the fields of environmental research are reviewed, namely X-ray absorption spectroscopy (XAS), X-ray fluorescence (XRF) spectroscopy and scanning transmission X-ray microscopy (STXM). In particular, the recent advances of the techniques in China are elaborated, and a selection of the applied examples are provided in the field of environmental science. Finally, the perspectives of synchrotron-based X-ray techniques are discussed. With their great progress and wide application, the techniques have revolutionized our understanding of significant geo- and bio-chemical processes. It is anticipatable that synchrotron-based X-ray techniques will continue to play a significant role in the fields and significant advances will be obtained in decades ahead.     

Relaxometric and magnetic characterization of ultrasmall iron oxide nanoparticles with high magnetization. Evaluation as potential T1 magnetic resonance imaging contrast agents for molecular imaging

Here we report on the synthesis of ultrasmall gamma-Fe2O3 nanoparticles (5 nm) presenting a very narrow particle size distribution and an exceptionally high saturation magnetization. The synthesis has been carried out by decomposition of an iron organometallic precursor in an organic medium. The particles were subsequently stabilized in an aqueous solution at physiological pH, and the colloidal dispersions have been thoroughly characterized by complementary techniques. Particular attention has been given to the assessment of the mean particle size by transmission electron microscopy, X-ray diffraction, dynamic light scattering, magnetic, and relaxometric measurements. The good agreement found between the different techniques points to a very narrow particle size distribution. Regarding the magnetic properties, the particles are superparamagnetic at room temperature and present an unusually high saturation magnetization value. In addition, we describe the potential of these particles as specific positive contrast agents for magnetic resonance molecular imaging.     

High pressure effects in anaesthesia and narcosis

There is growing interest in determining the effects of high pressure on biological functions. Studies of brain processes under hyperbaric conditions can give a unique insight into phenomena such as nitrogen narcosis, inert gas anaesthesia, and pressure reversal of the effects of anaesthetic and narcotic agents. Such research may shed light on the action of anaesthetics, which remains poorly understood, and on the nature of consciousness itself. Various studies have established the behavioural response of organisms to hyperbaric conditions, in the presence or absence of anaesthetic agents. At the molecular level, X-ray crystallography has been used to investigate the incorporation of species like Xe in hydrophobic pockets within model ion channels that may account for pressure effects on neuronal transmission. New magnetic resonance imaging techniques are providing tomographic three-dimensional images that detail brain structure and function, and that can be correlated with behavioural studies and psychological test results. Such whole organ techniques are linked to the molecular scale via voltage-sensitive dye (VSD) imaging studies on brain slices that provide time-resolved images of the dynamic formation and interconnection of inter-neuronal complexes. The VSD experiments are readily adapted to in situ studies under high pressure conditions. In this tutorial review we review the current state of knowledge of hyperbaric effects on brain processes: anaesthesia and narcosis, recent studies at the molecular level via protein crystallography at high pressure in a Xe atmosphere, and we also present some preliminary results of VSD imaging of brain slices under hyperbaric conditions.     

Analysis of chemical dynamics in microenvironments

A variety of techniques exist that provide chemical information in the form of a spatially resolved image. For example, magnetic resonance imaging has significant advantages for biological applications because it allows measurements in intact tissues. However, it is restricted at the present time to species of high concentration. The most common approach for chemically selective imaging is to use optical microscopy coupled with fluorescence measurements. A variety of fluorophores with high selectivity for specific ions are commercially available and are readily used in such applications. While imaging techniques provide an overall view of the microenvironment, probes that give a high fidelity view of a specific species and its concentration at a single location are also useful. Thus, there is particular interest in developing local sampling techniques. Electrochemical techniques, both potentiometric and amperometric, are particularly useful in this regard. For example, neurotransmitters, compounds secreted from nerve terminals to relay information from one neuron to another, can readily be examined with electrodes of micrometer dimensions. In this way, the mechanisms that control the secretion and the regulation of these compounds in the extracellular space can be evaluated. These tools can also be used at the level of single cells, and when placed at different locations, can be used to provide a chemical image. This approach essentially represents a marriage of electrochemical techniques with those of the scanning microscopies, an area that will see considerable growth in the new millennium.     

分子影像探针

分子影像是近年出现并迅速发展的一个生物医学领域,在疾病的治疗与诊断中发挥着重要作用。同时它又是一门交叉学科,涉及化学、医学、生物、计算机科学、放射科学、材料科学等。分子影像的发展除了需要先进的成像设备外,最关键的是合成新型而高效的成像探针。目前,分子影像探针广泛应用于科学研究和临床,并且也取得了巨大进步。本文主要综述了5种常见的分子影像探针:超声成像探针、X-射线计算机断层成像探针、光学成像探针、核磁共振成像探针、正电子发射计算机断层扫描成像探针,并对分子影像探针的应用进行了概述,最后对分子影像探针的发展进行了展望。     

Recent and future developments in the use of radiation for the study of objects of cultural heritage significance

Until recently, items of cultural heritage significance have been studied only using laboratory-based techniques. Improvements in the design of synchrotron radiation sources have made it possible to undertake experiments on objects of cultural heritage experience which had hitherto been impossible. Experimental techniques used in conservation science studies range from infrared microscopy to X-ray diffraction and fluorescence (both micro- and macro-diffraction), to small and wide angle X-ray scattering (SAXS/WAXS) (both micro- and macro-scattering). Here, we describe studies of important artefacts held by Australian national collecting agencies using both laboratory- and synchrotron-based analytical techniques and particle beam X-ray emission (PIXE). As well, a new technique for studying easel paintings, hyperspectral imaging, will be introduced.     

Functional tumor imaging based on inorganic nanomaterials

Inorganic nanomaterials have attracted substantial research interest due to their unique intrinsic physicochemical properties.We highlighted recent advances in the applications of inorganic nanoparticles regarding their imaging efficacy, focusing on tumor-imaging nanomaterials such as metal-based and carbon-based nanomaterials and quantum dots. Inorganic nanoparticles gain excellent in vivo tumor-imaging functions based on their specific characteristics of strong near-infrared optical absorption and/or X-ray attenuation capability. The specific response signals from these novel nanomaterials can be captured using a series of imaging techniques, i.e., optical coherence tomography(OCT), X-ray computed tomography(CT) imaging, two-photon luminescence(TPL), photoacoustic tomography(PAT), magnetic resonance imaging(MRI), surface-enhanced Raman scattering(SERS) and positron emission tomography(PET). In this review, we summarized the rapid development of inorganic nanomaterial applications using these analysis techniques and discussed the related safety issues of these materials.     

Magnetic nanoparticles--templated assembly of protein subunits: a new platform for carbohydrate-based MRI nanoprobes

A new approach for the preparation of carbohydrate-coated magnetic nanoparticles is reported. In a first step, we show that the pH-driven assembly-disassembly natural process that occurs in apoferritin protein is effective for the encapsulation of maghemite nanoparticles of different sizes: 4 and 6 nm. In a second step, we demonstrate that the presence of functional amine groups in the outer shell of apoferritin allows functionalization with two carbohydrates, N-acetyl-D-glucosamine and d-mannose. High-resolution electron microscopy (HREM), high angle annular dark field scanning electron microscopy (HAADF-STEM), electron energy loss spectroscopy (EELS), X-ray diffraction (XRD), and SQUID technique have been used to characterize the magnetic samples, termed herein Apomaghemites. The in vivo magnetic resonance imaging (MRI) studies showed the efficiency in contrasting images for these samples; that is, the r(2) NMR relaxivities are comparable with Endorem (a commercial superparamagnetic MRI contrast agent). The r(2) relaxivity values as well as the pre-contrast and post-contrast T(2)*-weighted images suggested that our systems could be used as perspective superparamagnetic contrast agents for magnetic resonance imaging (MRI). The carbohydrate-functionalized Apomaghemite nanoparticles retained their recognition abilities, as demonstrated by the strong affinity with their corresponding carbohydrate-binding lectins.