激光技术在农产品质量检测中的研究进展

近年来激光在农业领域得到广泛的应用和研究,其中的一个最新进展是将激光技术应用于农产品内部品质和安全性检测。本文介绍了农产品质量检测中的几种激光技术,包括应用激光的吸收与反射技术来检测农产品糖酸度、质地、PH值、成熟度、干物质等;应用激光诱导荧光技术来检测农产品的农药残留、叶绿素、成熟度;应用激光拉曼光谱技术来检测农产品水果损伤、农药残留。对农产品激光检测的未来发展趋势进行了探讨和展望。     

胃癌患者手术前后血清的激光拉曼光谱研究

为了探讨胃癌患者血清光谱在手术前后的变化及临床应用价值,用光谱法分别检测了30例胃癌细胞培养液、20例健康人血清和41例胃癌患者手术前、后血清的激光拉曼光谱。结果表明细胞培养液的拉曼光谱与空白对照有明显不同,且峰值与培养时间增成正相关;胃癌患者血清的拉曼光谱与健康人有显著差异;手术后胃癌患者血清的拉曼光谱峰值比术前明显降低。研究表明拉曼光谱可以作为胃癌细胞体外研究的检测手段,并有潜力成为胃癌筛查、预后监测及疗效判断的新方法。     

光声光谱技术在生物医学领域的发展与应用

光声光谱（特别是激光光声光谱）技术已成为分子光谱学的一个重要分支,其技术特点为生物医学材料的研究提供了一种灵敏而又无损材料的有效办法,是研究复杂生物体所不缺少的分析工具,本文简述了光声光谱的基本理论及特点,介绍了光声光谱在生物学,医学领域的发展和应用情况。     

水稻病毒激光喇曼光谱的初步探讨

本文初步探讨水稻病毒激光喇曼光谱,分析了谱线与病毒中核酸蛋白质结构的关系。确信应用激光喇曼光谱研究水稻病毒是具有信息量大、高灵敏及高分辨本领的。     

半导体激光辐照DNA的光谱分析

本文通过半导体激光等辐照源对ＤＮＡ辐照,研究激光、紫外、普通红光对ＤＮＡ吸收光谱的影响。发现激光（６６０ｎｍ）与紫外（峰值波长２５４ｎｍ）均能使ＤＮＡ吸收峰值改变,表明它们均能被ＤＮＡ吸收,与ＤＮＡ发生作用,从而使ＤＮＡ构型发生变化,但激光、紫外与ＤＮＡ作用机理是不同的。而普通红光（峰值波长６６０ｎｍ）对ＤＮＡ光谱无甚影响,这说明了激光与ＤＮＡ作用的非线性共振吸收存在。并发现在激光辐照ＤＮＡ时,激光剂量不同以及ＤＮＡ溶液浓度不同,对ＤＮＡ光谱的影响也不同。这些结果对激光育种和激光生物学实验有一定参考价值。     

“中国遗传学会第十届全国激光生物学学术会议”将在武汉召开

会议主题 激光生物学的发展和应用 1学术报告： 大会将邀请院士和特聘教授等作特邀报告和专题报告,并安 排分组交流。第一分会场：包括激光生物学和生物光子学的基础研究,激光生物技术（含微束照射技术、光镊技术、成像技术、光谱技术、共聚焦扫描显微技术、细胞分流技术等）及其仪器的研制、应用。     

利用飞秒激光研究微液滴的冻结相变特性

对微液滴冻结行为的认识在低温生物学、分析化学等方面具有重要意义.引入飞秒激光实验手段研究液滴及微量生物材料(蛋白)的冻结相变特性.实验考察了样品在多次冻结过程中荧光光谱的变化规律,结果表明:生物材料与非生物材料在冻结及复温过程中的荧光光谱变化趋势存在差异,非生物试剂在冻结过程中光谱下降,经历复温后,其光谱可回复到初始状态;而蛋白在冻结过程中光谱上升,经历复温后,由于降温/升温过程对其造成的不可逆损伤,光谱无法回复到初始状态.基于此提出了用以评估生物样品活性的非接触式飞秒激光测量方法.     

拉曼光谱技术在微生物学中的应用

拉曼光谱具有快速、灵敏、无损、实时监测等显著特点,在微生物学领域得到广泛应用。分别介绍共焦显微拉曼光谱、共振拉曼光谱、表面增强拉曼光谱、拉曼成像、相干反斯托克斯拉曼光谱、激光镊子拉曼光谱和Raman-FISH的原理和特点,并重点总结和分析不同拉曼光谱技术在微生物的结构、化学组成,以及代谢过程等相关研究中的应用优势。合理利用这些技术在基础微生物、发酵微生物和微生物诊断等方面具有潜在的应用价值。     

用于浮游植物探测的三维激光诱导荧光光谱系统

本文介绍一个针对浮游植物现场探测的三维激光诱导荧光（3D-LIF）光谱系统。该系统以波长可调谐激光器为光源,使用光栅光谱仪进行光谱分光,输出光谱范围380 nm ～800 nm,并选用32通道光电倍增管模组作为光电探测器。光栅光谱仪和光电倍增管模组之间的耦合选用芯径0．2 mm 的光纤束,对应光谱分辨率约为3 nm,以此采集接收的31通道发射荧光光谱,其光谱范围为410 nm ～710 nm,光谱带宽约10 nm。光电转换电路的模拟带宽约为20 MHz,数据采集频率50 MHz,分辨率14 bit。基于研发的光谱系统,采用光学参量放大器（OPO）以获得405 nm ～615 nm 可调谐激发光源,在实验室对三十余种中国海常见的浮游植物的3D-LIF 光谱进行了测量。测量结果证实了系统的稳定性和用于藻种分类和识别研究的有效性。系统中的激光器和望远镜可灵活更换,接收的光谱范围和光谱分辨率等参数可便利调节,因此,该系统可望发展成为用于现场探测的3D-LIF 光谱系统。     

超短脉冲技术测量癌细胞荧光光谱与荧光寿命

研究用于癌症诊断与治疗的光敏剂血卟啉（hematoporphyrin derivative,HPD）的超快光动力学过程,采用超短脉冲激光光谱技术和皮秒时间相关单光子计数系统,测量经血卟啉培养的活体癌细胞与正常细胞的荧光光谱、荧光寿命特性及荧光峰值强度随时间变化曲线,并测量单一细胞内部不同位置的荧光寿命特性,观测到：癌细胞样品在645 nm处具有特有的光谱谱峰;癌细胞样品荧光寿命的快成分约150 ps慢成分约1200 ps,而正常细胞样品快成分约300 ps慢成分约2500 ps;癌细胞样品的荧光峰值强度经12小时衰减约10%,而正常细胞样品衰减约55%;在细胞内部荧光寿命300 ps的快成分十分显著,且中心部位血卟啉浓度最高.癌细胞与正常细胞的荧光光谱、荧光寿命特性及荧光峰值强度随时间变化曲线相差十分明显,反映了癌细胞与正常细胞对血卟啉亲和特性有显著的差异,测量结果确认了荧光光谱技术诊断与治疗癌症的可行性,并对发展超短脉冲激光光谱技术早期诊断与治疗癌症具有重要的指导意义和临床应用价值.     

Recent applications of ATR FTIR spectroscopy and imaging to proteins

Attenuated Total Reflection (ATR) Fourier Transform Infrared (FTIR) spectroscopy is a label-free, non-destructive analytical technique that can be used extensively to study a wide variety of different molecules in a range of different conditions. The aim of this review is to discuss and highlight the recent advances in the applications of ATR FTIR spectroscopic imaging to proteins. It briefly covers the basic principles of ATR FTIR spectroscopy and ATR FTIR spectroscopic imaging as well as their advantages to the study of proteins compared to other techniques and other forms of FTIR spectroscopy. It will then go on to examine the advances that have been made within the field over the last several years, particularly the use of ATR FTIR spectroscopy for the understanding and development of protein interaction with surfaces. Additionally, the growing potential of Surface Enhanced Infrared Spectroscopy (SEIRAS) within this area of applications will be discussed. The review includes the applications of ATR FTIR imaging to protein crystallisation and for high-throughput studies, highlighting the future potential of the technology within the field of protein structural studies and beyond.     

Monitoring biological wastewater treatment processes: recent advances in spectroscopy applications

Biological processes based on aerobic and anaerobic technologies have been continuously developed to wastewater treatment and are currently routinely employed to reduce the contaminants discharge levels in the environment. However, most methodologies commonly applied for monitoring key parameters are labor intensive, time-consuming and just provide a snapshot of the process. Thus, spectroscopy applications in biological processes are, nowadays, considered a rapid and effective alternative technology for real-time monitoring though still lacking implementation in full-scale plants. In this review, the application of spectroscopic techniques to aerobic and anaerobic systems is addressed focusing on UV–Vis, infrared, and fluorescence spectroscopy. Furthermore, chemometric techniques, valuable tools to extract the relevant data, are also referred. To that effect, a detailed analysis is performed for aerobic and anaerobic systems to summarize the findings that have been obtained since 2000. Future prospects for the application of spectroscopic techniques in biological wastewater treatment processes are further discussed.     

Assessment of Lignocellulosic Biomass Using Analytical Spectroscopy: an Evolution to High-Throughput Techniques

Lignocellulosic biomass has been proposed as an option for reducing global dependence on nonrenewable energy sources, such as oil. Selection and development of biomass feedstocks that efficiently yield the maximum fuel or biomaterial requires the availability of reliable methods for compositional and structural characterization of plant material. Many standard methods for biomass analysis are laborious and slow, and employ a variety of harsh reagents requiring some degree of remediation. The use of simpler and more rapid spectroscopic methods has proved invaluable in analyzing biomass. In the twenty-first century, researchers have employed techniques such as Raman, mid-infrared, and near-infrared spectroscopy for a wide range of applications in endeavors to further understand biofuel feedstocks. While many methods remain time consuming and expensive, a growing interest in high-throughput spectroscopic techniques has provided faster and larger scale feedstock screening for desirable traits. This review seeks to provide an overview of both high-throughput techniques and those requiring longer analysis times but still providing abundant qualitative and quantitative data. While applications of these instrumental methods have been researched for decades, more recent developments will be discussed here.     

Raman Spectroscopy of Microbial Pigments

Raman spectroscopy is a rapid nondestructive technique providing spectroscopic and structural information on both organic and inorganic molecular compounds. Extensive applications for the method in the characterization of pigments have been found. Due to the high sensitivity of Raman spectroscopy for the detection of chlorophylls, carotenoids, scytonemin, and a range of other pigments found in the microbial world, it is an excellent technique to monitor the presence of such pigments, both in pure cultures and in environmental samples. Miniaturized portable handheld instruments are available; these instruments can be used to detect pigments in microbiological samples of different types and origins under field conditions.     

Polysaccharide-polynucleotide complexes VIII. Cation-induced complex formation between polyuridylic acid and schizophyllan

Raman spectroscopy has recently been applied ex vivo and in vivo to address various biomedical issues such as the early detection of cancers, monitoring of the effect of various agents on the skin, determination of atherosclerotic plaque composition, and rapid identification of pathogenic microorganisms. This leap in the number of applications and the number of groups active in this field has been facilitated by several technological advancements in lasers, CCD detectors, and fiber-optic probes. However, most of the studies are still at the proof of concept stage. We present a discussion on the status of the field today, as well as the problems and issues that still need to be resolved to bring this technology to hospital settings (i.e., the medical laboratory, surgical suites, or clinics). Taken from the viewpoint of clinicians and medical analysts, the potential of Raman spectroscopic techniques as new tools for biomedical applications is discussed and a path is proposed for the clinical implementation of these techniques.     

Biofluid spectroscopic disease diagnostics: A review on the processes and spectral impact of drying

The complex patterns observed from evaporated liquid drops have been examined extensively over the last 20 years. Complete understanding of drop deposition is vital in many medical processes, and one which is essential to the translation of biofluid spectroscopic disease diagnostics. The promising use of spectroscopy in disease diagnosis has been hindered by the complicated patterns left by dried biological fluids which may inhibit the clinical translation of this technology. Coffee‐ring formation, cracking and gelation patterns have all been observed in biofluid drops, and with surface homogeneity being a key element to many spectroscopic techniques, experimental issues have been found to arise. A better understanding of the fundamental processes involved in a drying droplet could allow efficient progression in this research field, and ultimately benefit the population with the development of a reliable cancer diagnostic.      

Chiral ionic liquids: a compendium of syntheses and applications (2005-2012)

In recent years, the field of chiral ionic liquids (CILs) has undergone exponential growth. As the technology has advanced, new ways of synthesizing stable and structurally diverse ionic liquids have been established. This has led to heretofore unknown applications of CILs as well as in improving efficiency of previously identified applications. In this review article we have compiled a comprehensive database containing structures and physical properties of notable CILs that have been synthesized during the last 6 years. Their applications in the fields of asymmetric organic synthesis, spectroscopy, and chromatography are also illustrated. This is an expansion of our previous review, which covered the literature before 2005.     

In‐line monitoring of amino acids in mammalian cell cultures using raman spectroscopy and multivariate chemometrics models

The application of PAT for in‐line monitoring of biopharmaceutical manufacturing operations has a central role in developing more robust and consistent processes. Various spectroscopic techniques have been applied for collecting real‐time data from cell culture processes. Among these, Raman spectroscopy has been shown to have advantages over other spectroscopic techniques, especially in aqueous culture solutions. Measurements of several process parameters such as glucose, lactate, glutamine, glutamate, ammonium, osmolality and VCD using Raman‐based chemometrics models have been reported in literature. The application of Raman spectroscopy, coupled with calibration models for amino acid measurement in cell cultures, has been assessed. The developed models cover four amino acids important for cell growth and production: tyrosine, tryptophan, phenylalanine and methionine. The chemometrics models based on Raman spectroscopy data demonstrate the significant potential for the quantification of tyrosine, tryptophan and phenylalanine. The model for methionine would have to be further refined to improve quantification.     

Professor Tatsuo Miyazawa: from molecular structure to biological function

The late Prof. Tatsuo Miyazawa was an outstanding physical chemist, who established a number of spectroscopic methods to analyse the structures of proteins, peptides and nucleotides, and used them to understand molecular functions. He developed an infrared spectroscopic method to quantitatively analyse the secondary structures, α-helices and β-strands, of proteins. He successfully utilized nuclear magnetic resonance (NMR) methods to determine the conformations of peptides and proteins, particularly with respect to the interactions with their target molecules, which served as a solid basis for the wide range of applications of NMR spectroscopy to life science research. For example, he found that physiologically active peptides are randomly flexible in solution, but assume a particular effective conformation upon binding to their functional environments, such as membranes. He also used NMR spectroscopy to quantitatively analyse the conformer equilibrium of nucleotides, and related the dynamic properties of the modified nucleosides naturally-occurring in transfer ribonucleic acids (tRNAs) to their roles in correct codon recognition in protein synthesis. Furthermore, he studied the mechanisms of protein biosynthesis systems, including tRNA and aminoacyl-tRNA synthetases. Inspired by the structural mechanism of amino acid recognition by aminoacyl-tRNA synthetases, as revealed by NMR spectroscopy, he initiated a new research area in which non-natural amino acids are site-specifically incorporated into proteins to achieve novel protein functions (alloprotein technology).