近红外光谱技术在神经外科患者脑氧和血流动力学监测中的应用研究进展

神经外科患者,尤其是脑血流自动调节功能受损的重症患者,脑氧饱和度是反应患者脑组织氧代谢情况的重要指标,实时、准确的脑氧饱和度监测方法对于指导选择有效的治疗措施和判断患者预后具有重要价值。基于血红蛋白不同氧合状态,即氧合血红蛋白(oxyhemoglobin,Hb O2),还原血红蛋白(deoxygenated hemoglobin,Hb)具有的差异性分子光谱,近红外光谱技术near infrared spectroscopy,NIRS)可监测人体局部组织氧饱和度。由于近红外射线能穿透颅骨直接获得脑组织内平均氧饱和度的特性,可协助临床实现无创持续监测脑氧饱和度的目的,近年来该技术在神经外科领域的应用研究获得了迅速发展,在颅脑创伤和其它神经外科疾病的应用研究中均取得了显著的进展,本文将对最新研究结果及其意义和未来发展方向进行综述。     

近红外光谱技术在食品产地溯源中的应用进展

食品产地溯源是食品安全追溯制度的重要工作。近红外光谱技术(near infrared spectroscopy,NIRS)作为一种兼具快速、简便、不破坏试样、分析过程无试剂消耗等优点的新兴绿色检测技术,近年来被逐步应用于食品产地溯源的研究中。简要介绍了应用于食品产地溯源研究中近红外光谱技术常用的化学计量学技术及软件平台,同时概述了近年来该技术在国内外食品产地溯源中的研究进展,分析了在目前产地溯源研究中的优势和存在的问题,以期为近红外光谱溯源技术的进一步发展提供参考。     

近红外光谱技术在运动脑功能研究中的应用

近红外光谱是一种评估生物组织氧合水平的无创性光学技术,这一技术以血液动力学原理为基础,能实时监测局部脑区的动态变化。近红外光谱作为一种客观的测量工具,在人体运动科学领域广泛运用。近红外光谱技术可用于区别体能水平、监控耐力训练和抗阻训练过程特征以及考察运动中的认知活动变化。本文综述了近红外光谱技术原理及其在抗阻运动、运动中枢疲劳和运动认知领域的运用,并对近红外光谱在运动科学领域的未来研究趋向作了分析。     

近红外光谱技术在猫脑射频热凝毁损中的应用研究

目的:探索近红外光谱(nears)技术用于立体定向靶点毁损术中实时监测的可行性。方法:利用猫脑建立体内不同毁损时间、温度下的毁损灶体积模型,通过病理检测及近红外光谱仪观察并记录脑组织靶点毁损时的NIRS尤其是优化散射系数()的变化情况。结果:不同温度、不同时间温度点下NIRS出现特征性变化曲线。并建立时间、温度及三维模型。结论:利用NIRS实时活体在位监测猫脑射频神经核团毁损术是科学、可行的,优化散射系数是监测的良好指标,比以往单凭经验的作法更科学、更准确。     

近红外光谱技术在水果成熟期预测中的应用(综述)

近红外光谱技术以快速、准确和多组分同步分析等优势,近年来在水果果实发育、成熟期预测和品质检测等方面应用广泛,并在果实品质无损检测分析技术研究方面取得重要进展。本文综述近红外光谱技术的基本原理和特点,分析近红外光谱技术在果实成熟期预测中的研究现状和存在问题,并提出今后研究方向。     

近红外光谱技术在猫脑射频热凝毁损中的应用研究

目的：探索近红外光谱（nears）技术用于立体定向靶点毁损术中实时监测的可行性。方法：利用猫脑建立体内不同毁损时间、温度下的毁损灶体积模型,通过病理检测及近红外光谱仪观察并记录脑组织靶点毁损时的NIRS尤其是优化散射系数（）的变化情况。结果：不同温度、不同时间温度点下NIRS出现特征性变化曲线。并建立时间、温度及三维模型。结论：利用NIRS实时活体在位监测猫脑射频神经核团毁损术是科学、可行的,优化散射系数是监测的良好指标,比以往单凭经验的作法更科学、更准确。     

近红外反射光谱分析技术在植物育种与种质资源研究中的应用

近年来近红外反射光谱分析技术(NIRS)在植物育种与种质资源研究中的应用已成为一个活跃的研究领域,本从NIRS分析植物的种类和品质类型、种质资源品质分析和评价、加速品质育种进程等方面作一综述,并对NIRS在作物育种中的应用作了探讨。     

NIRS定量分析羽衣甘蓝油含量、蛋白质含量数学模型的建立

应用近红外反射光谱技术(NIRS)采集807份羽衣甘蓝种子光谱数据,然后挑选250份材料,用经典化学方法测试种子油含量和饼粕蛋白质含量.通过偏最小二乘法(PLS)、改良最小二乘法(MPLS)和不同光谱散射及数学处理技术来建立NIRS定量分析数学模型.种子油含量和饼粕蛋白质含量模型的交叉检验相关系数(1-VR)分别为0 9180、0 9062,交叉检验标准差(SECV)分别为1 0606、0 8720,校正标准差(SEC)分别为0 9267、0 8119.两种模型的外部检验相关系数(RSQ)分别为0 949、0 915,相对误差分别小于3 60%、2 70%,预测标准差(SEP)分别为0 881、0 779,检验偏差(BIAS)均较小分别为-0 054、-0 062.研究表明:这两个数学模型的分析结果具有较高的精确度,在品质育种中具有较好的应用前景.     

近红外光谱无创血糖检测

糖尿病患者减少由糖尿病引起的并发症的重要手段是自我监测,目前主要的检测方法是有创或微创的,给患者不可避免的带来痛苦和不便。本文对利用近红外光谱技术进行无创血糖检测研究进行了综述,分析了其优缺点,总结了目前研究原理,并结合我们的研究提出了一些看法。     

细菌光谱检测方法与分子机制的研究进展

细菌是人类最常见的致病源之一,不仅严重危害人类健康和公共卫生安全,还带来了巨额的医疗支出。快速而准确的细菌检测对细菌感染的治疗具有重要的意义。光谱检测方法不但可以快速实时地获得细菌的分类、含量以及功能状态等信息,而且具有操作简单、非侵入性的优势,在细菌检测领域具有巨大的潜力。本文介绍了拉曼光谱、太赫兹光谱、可见光和近红外光光谱、荧光光谱在细菌检测方面的研究与应用,并对可见光和近红外光光谱的分子机制——光靶点,包括含有视网膜发色团的细菌视紫红质(CBCRs)、带有四吡咯发色团的拟菌植物色素、带有对香豆酸发色团的光活性黄蛋白(PYP)、带有黄素单核苷酸(FMN)的光氧压力(LOV)结构域、带有黄素腺嘌呤二核苷酸(FAD)发色团的隐色剂和含有FAD的蓝光感应域等进行了阐述。最后,针对现有细菌光谱检测技术的优缺点提出了细菌检测技术的优化策略,希望对细菌的光谱检测研究提供帮助。     

Advances of infrared spectroscopy in natural product research

Natural product's properties are related to certain classes of compounds such as alkaloids, flavonoids, essential oils and others. Traditionally, separation techniques including thin layer chromatography (TLC), liquid chromatography (LC), gas chromatography (GC) and capillary electrophoresis (CE) even hyphenated to mass spectrometry (MS) were used for the elucidation, qualitative and quantitative analysis of individual compounds.In food industry, spectroscopic investigations using infrared radiation have been used to monitor and evaluate the composition and quality already since the early sixties. During the last four decades near-infrared spectroscopy (NIR; 800–2500 nm; 12,500–4000 cm⁻¹) has become one of the most attractive and used methods for analysis for the following reasons: it represents a non-invasive analytical tool allowing a fast and simultaneous qualitative and quantitative characterization of natural products and their constituents. Additionally, the development of custom-made hand-held instruments enables in-field measurement for determining the optimum harvest time.Attenuated total reflection (ATR) and Fourier transform infrared (FTIR) spectroscopic imaging are suitable not only for the differentiation of different plant species, but also to distinct various ingredients within a plant. FTIR spectroscopic microscopy enables molecular imaging of complex botanical samples and therefore the detection and characterization of the molecular components of biological tissue.In the present contribution, the principle, technique and methodology of the different infrared spectroscopic methods are described followed by a discussion of quantitative and qualitative application possibilities in the field of natural product analysis.     

Selected latest applications of molecular spectroscopy in natural product analysis

The field of molecular vibrational spectroscopy applied to natural products is advancing extremely fast. Traditionally applied separation techniques (LC-, μ-LC–MS, GC, CE-MS) offer the advantages of high selectivity/sensitivity, but their application for routine quality control is limited due to long analyses times. Therefore, molecular spectroscopy in combination with multivariate analysis (MVA) enjoys excellent reputation, because of the fast and non-invasive measurement enabling the analysis of several physical and chemical parameters simultaneously. Near infrared (NIR; 4.000–10.000 cm⁻¹), attenuated total reflection (ATR; 400–4.000 cm⁻¹), Raman and far ultraviolet (FUV;120–200 nm) spectroscopy have permanently increased their efficiencies for quality control of predominantly food stuff, but also of other natural products including mainly medicinal plants. All four techniques enable not only a quantitative analysis of potent ingredients, but also qualitative fingerprint analysis for the discrimination of, e.g., species and/or geographic origin, respectively. Thereby, each individual spectroscopic technique possesses its specific strength. Powerful miniaturized portable spectrometers based on linear variable tuneable filter (LVTF) or micro-electro-mechanical systems (MEMS) are helpful in order to prevent consumers from deception on one hand, on the other hand they represent powerful analytical instruments for measurements in the field. 2-Dimensional correlation spectroscopy (2DCOS) represents a powerful technique for monitoring the dynamics of a system including temperature stability, extraction procedures etc. Imaging and mapping spectroscopy using infrared radiation and/or Raman scattering are not only suitable for classification of food stuff including e.g. maize kernels and/or coffee beans, but also for localizing the distribution of ingredients down to a resolution of 4 μm.In the present contribution, the latest progresses of the different techniques are introduced and their applicability in the fields of natural product analysis will be discussed in detail by distinct selected applications.     

Status of THz-to-Visible Nanospectroscopy Development

Quite unexpectedly, THz and infraredspectroscopy has now a real chance to solveproblems in the nanosciences. This rests ona new microscope technique that overcomesthe Abbe diffraction limit, by using thenear field of a metal antenna in closeproximity to a scanned sample surface. HereI briefly summarize present activities inthe microwave, mid-infrared and visiblespectral ranges. It seems straightforwardand highly desirable to fill the existinggap between about 20 GHz and 20 THz, andattain spatial resolution of 10 nm andbelow also in this important part of theelectromagnetic spectrum.     

Quantitative analysis of biosurfactants using Fourier Transform Infrared (FT-IR) spectroscopy

A quick and simple technique has been developed that is suitable to quantify the concentration of most types of biosurfactants in a typical growth medium using infrared spectroscopy. The area of the peak due to the carbonyl bond of the biosurfactant was measured and compared to the area of the nitrile peak in an internal standard (anthracenecarbonitrile). This ratio showed a linear trend with the concentration of biosurfactant in the medium for concentrations from 0.2 to 3.2 g biosurfactant l^–1. The presence of hydrocarbons in the media and variations in the pH of the media did not interfere with the measurements.     

Interaction between hydroxyethyl starch and propofol: computational and laboratorial study

Background: Hydroxyethyl starch (HES) is one of the most used colloids for intravascular volume replacement during anesthesia. Aim: To investigate the existence of a chemical interaction between HES and the anesthetic propofol by in vitro propofol dosing, computational docking, and examination of a complex between propofol and HES by infrared (IR), ultraviolet (UV), and ¹H and ¹³C nuclear magnetic resonance (NMR) spectroscopy. Methods: Ten samples with human plasma mixed with HES or lactated Ringers (n?=?5 for each fluid) were prepared, and the propofol free fraction was quantified until 50?min, using gas chromatography-mass spectrometry. The docking study was performed between HES and propofol and compared with controls. The binding affinities between HES and the small molecules were evaluated by binding free energy approximation (ΔGb, kJ?mol^?1). The IR, UV, and NMR spectra were measured for propofol, HES, and a mixture of both obtained by the kneading method. Results: Propofol concentrations were significantly lower in the HES samples than in the LR samples (p?=?.021). The spectroscopic characterization of propofol combined with HES revealed differences in spectra and docking studies reinforced a potential interaction between propofol and HES. Conclusions: Propofol and HES form a complex with different physical-bio-chemical behavior than the single drugs, which may be an important drug interaction. Further studies should evaluate its clinical effects.     

Raman and FTIR microscopic imaging of colon tissue: a comparative study

Colon tissue constitutes a valid model for the comparative analysis of soft tissue by Raman and Fourier transform infrared (FTIR) imaging because it contains four major tissue types such as muscle tissue, connective tissue, epithelium and nerve cells. Raman microscopic images were recorded in the mapping mode using 785 nm laser excitation and a step size of 10 μm from three regions within a thin section that encompassed mucus, mucosa, submucosa, and longitudinal and circular muscle layers. FTIR microscopic images that were composed of 4, 8 and 9 individual images of 4096 spectra each were recorded from the same regions using a FTIR spectrometer coupled to a microscope with a focal plane array detector. Furthermore, Raman microscopic images were recorded at a step size of 2.5 μm from three ganglia that belong to the myenteric plexus. The results are discussed with respect to lateral resolution, spectral resolution, acquisition time and sensitivity of both modalities. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Flash-induced kinetic infrared spectroscopy applied to biochemical systems

A flash photolysis apparatus with monitoring infrared beam is described allowing measurements of relative transmission changes of 10^–3 in times of a few milliseconds. The investigation of the photodissociation of CO-myoglobin confirms the results obtained by static infrared difference spectroscopy. The application of our method to the rhodopsin/Meta II transition reveals signals which can tentatively be ascribed to the disappearance of the C=C-band of the protonated N-retinylidene Schiff base in rhodopsin. The developed method will be compared with other existing methods of kinetic vibronic spectroscopy such as kinetic resonance Raman spectroscopy and kinetic Fourier infrared spectroscopy.     

光谱法研究甲醇和盐酸对短梗霉黑色素的分离效果

应用紫外和红外光谱对甲醇和盐酸分离的短梗霉黑色素进行了分析。分析结果表明:甲醇和盐酸法分离的黑色素在紫外图谱215 nm处都有最大吸收峰,而甲醇法分离的黑色素其紫外图谱在260、280 nm处无吸收峰表明此法分离的黑色素不含核酸及蛋白质;红外图谱中,在3340 cm-1、1637 cm-1处有很强的吸收峰表现为黑色素的典型特征;同时在对照中发现盐酸多次处理后的黑色素显示较少的结构信息,说明盐酸沉降法有可能破坏黑色素的结构。由此选用甲醇作为沉淀剂有利于黑色素的纯化及确保其结构信息的完整,为进一步分析短梗霉黑色素的结构表征奠定了基础。