心肌梗死的红外光谱检测

目的建立鉴定心肌梗死的红外光谱法,探讨傅里叶红外光谱面扫描技术鉴别早期心肌缺血和陈旧性心肌梗死的可行性。方法利用傅里叶变换显微红外光谱面扫描成像技术对1例心肌梗死组织样品进行逐点扫描,观测细胞酰胺A带、CH3反对称伸缩、胶原蛋白三螺旋结构及核酸和磷酸脂质PO2反收缩振动频率的光谱分布情况,绘制梗死组织的红外光谱病理图像。结果酰胺A带及胶原蛋白三螺旋结构的高吸收区、CH3反对称伸缩及核酸和磷酸脂质PO2反收缩振动的低吸收区与梗死区符合。结论傅里叶红外光谱及面扫描技术可鉴定心肌梗死病理改变,酰胺A带和胶原蛋白三螺旋结构的红外光谱图改变可特征性的判别早期心肌缺血和陈旧性心肌梗死。     

实验性大鼠弥漫性轴索损伤的傅里叶红外光谱检测

目的探讨利用傅里叶红外光谱技术诊断弥漫性轴索损伤的可行性。方法利用HE染色、银染和β-APP免疫组化染色确认大鼠弥漫性轴索损伤模型,利用傅里叶变换显微红外光谱面扫描成像技术检测弥漫性轴索损伤区域酰胺Ⅱ带的光谱分布情况,得到弥漫性轴索损伤的红外光谱数据,绘制红外光谱病理图像。结果实验组与对照组的酰胺Ⅱ带红外光谱吸收度之间存在明显差异,红外光谱病理图像中酰胺Ⅱ带的高吸收区与弥漫性轴索损伤区符合。结论傅里叶红外光谱技术可对弥漫性轴索损伤进行病理形态学诊断。     

傅里叶红外光谱技术在法医学脑挫裂伤鉴定中的应用展望

脑挫裂伤是常见的一类颅脑损伤,单纯的组织病理学技术可能难以早期发现及精确诊断。傅里叶变换红外面扫描成像技术(FTIR-mapping)是病理学研究领域的新技术,因其结合了傅里叶变换红外光谱、红外显微镜技术以及面扫描成像技术的特点,具有测定方法简便、对样本无损、灵敏度高、准确、直观等优点,突破了传统技术的局限,能检测出发生了物质数量、结构以及构象变化但缺乏明显形态学变化的脑挫裂伤,从而实现早期精准地诊断脑挫裂伤。FTIR-mapping虽已能绘制某些损伤组织的红外光谱病理图像,但其在法医病理学中的价值有待全面深入开发。本文综述了脑挫裂伤的法医病理学研究进展以及傅里叶变换红外面扫描成像技术在法医病理学中的应用。     

家兔死后心肌酰胺A带的傅里叶变换红外光谱图像分析

目的 应用傅里叶变换红外光谱成像系统研究家兔心肌酰胺A带变化与死亡时间的关系.方法 将32只家兔处死后取出心脏,20℃保存,于48h内不同时间点取样并制作切片.用傅里叶变换红外光谱成像系统绘制酰胺A带图像,分析研究死后酰胺A带阳性与阴性面积比的变化规律. 结果 48h内随死亡时间(x)的延长,酰胺A带的阳性与阴性面积比...     

傅里叶变换显微红外光谱结合机器学习算法鉴定电击伤

目的基于傅里叶变换显微红外光谱结合机器学习算法分析猪皮肤电击伤、烧伤及擦伤的差异,构建3种皮肤损伤鉴定模型,筛选电击伤特征性标志物,为皮肤电流斑鉴定提供新方法。方法建立猪皮肤电击伤、烧伤及擦伤的模型,使用传统HE染色检验不同损伤的形态学改变。运用傅里叶变换显微红外技术检测表皮细胞光谱,运用主成分、偏最小二乘法分析损伤的分类情况,运用线性判别和支持向量机构建分类模型,因子载荷筛选特征性标志物。结果与对照组相比,电击伤、烧伤及擦伤组的表皮细胞均呈现出极化现象,以电击伤、烧伤组更为明显。通过主成分和偏最小二乘法分析可区分不同类型损伤,线性判别、支持向量机模型均能够有效诊断不同损伤。2 923、2 854、1 623、1 535 cm-1吸收峰在不同损伤组显示出明显的差异,电击伤的2 923 cm-1吸收峰峰强最高。结论傅里叶变换显微红外光谱结合机器学习算法为诊断皮肤电击伤、鉴定电击死提供了新技术。     

傅立叶显微红外化学成像在朱墨时序鉴定中的应用研究

目的建立朱墨时序的傅里叶显微红外成像检验方法。方法根据印文及油墨的红外光谱特征峰,使用傅立叶变换红外（FTIR）成像系统直接对纸张上印文及文字油墨进行化学成像,根据成像特征从而判断朱墨时序。结果先打印后盖章的红外成像中油墨字迹的红外成像不完整,有被印章所覆盖的痕迹,而印章的红外成像完整,在字迹中可见印章成像斑点。先盖章后打印的红外成像中油墨字迹的红外成像完整,没有被印章所覆盖,而印章的红外成像不完整,被字迹的油墨所覆盖。结论该方法较传统的鉴定方法更加快速、简单,可以更加直观的反映行文顺序,并且具有不破坏检验样本的特点。     

外伤性癫痫灶β-折叠蛋白的FTIR-mapping研究

目的研究外伤性癫痫致痫灶β-折叠蛋白的红外光谱改变。方法利用傅里叶红外光谱面扫描成像技术对大鼠外伤性癫痫脑组织标本进行检测,获得β-折叠蛋白结构的光谱数据,绘制致痫灶的红外光谱图像。结果致痫灶可见明显的β-折叠蛋白结构高吸收区,高吸收区色差、吸收度与低吸收区存在明显不同。结论外伤性癫痫致痫灶广泛存在β-折叠结构跨膜蛋白的改变,具有β-折叠结构的跨膜蛋白广泛参与了外伤性癫痫的发生。     

光谱成像检验技术

光谱成像组合了光谱技术和成像技术。通过运用成像光谱仪 ,光谱成像方法可以记录被检验物体在一个较宽光谱范围内均匀密集分布的窄波段反射光或荧光亮度分布影像 ,形成含有物体亮度信息和光谱信息的光谱影像集。这种技术方法可以用于物证的形态特征检验和物质成分检验。相对传统光谱检验或成像检验技术 ,光谱成像检验的能力和效果都具有明显优势。     

外伤性癫痫致痫灶α-螺旋结构蛋白质的FTIR-mapping研究

目的研究外伤性癫痫致痫灶α-螺旋结构蛋白质的红外光谱改变。方法利用傅里叶红外光谱面扫描成像技术对大鼠外伤性癫痫脑组织标本进行检测,获得α-螺旋结构的光谱数据,以及红外光谱图像。结果致痫灶可见明显的α-螺旋结构高吸收区,高吸收区色差与吸收度与低吸收区存在明显不同。结论外伤性癫痫致痫灶广泛存在α-螺旋结构跨膜蛋白的改变,具有α-螺旋结构的跨膜蛋白广泛参与了外伤性癫痫的发生。     

高温环境下死亡大鼠肾傅里叶显微红外光谱变化

目的应用傅里叶显微红外光谱(Fourier transform infrared microspectroscopy,FTIR-MSP)技术分析高温死亡大鼠肾的化学基团变化,为高温死亡鉴定提供新的途径与方法。方法建立不同死亡原因动物模型并分组,包括高温死亡组、脑干损伤死亡组、失血性休克死亡组、窒息死亡组,大鼠死亡后立即提取其肾组织,使用FTIR-MSP技术采集肾小球区域的红外光谱。结果高温死亡组大鼠肾小球组织在3 290、3 070、2 850、1 540及1 396 cm-1处吸收峰强度增高(P0.05),A1 650/A3 290与A1 650/A1 540的比值降低(P0.05)。结论应用FTIR-MSP技术分析肾组织化学基团变化可作为高温死亡鉴定的辅助诊断方法。     

Characteristics of electrically injured skin from human hand tissue samples using Fourier transform infrared microspectroscopy

This technical note describes a method for distinguishing normal skin tissue samples from those electrically injured by Fourier transform infrared microspectroscopy (FTIR MSP). Furthermore, the infrared spectral features of electrically injured cells and tissues were evaluated to identify molecular changes in epidermal cells. In the present study, 20 human hand tissue samples were evaluated macroscopically and histopathologically. The electrically injured skin samples were subdivided into 2 regions [normal cell regions (NCRs) and polarized cell regions (PCRs)] and 14 major spectral absorption bands were selected. The spectral results showed that the band absorbance at 1080, 1126, 1172, 1242, 1307, 1403, 1456, 1541, 2852, 2925, 2957, 3075, and 3300 cm^− 1 increased significantly both in the stratum and non-stratum corneum of the PCRs in electrically injured skin tissues samples. No significant difference was found between normal skin and the NCR of the electrically injured skin samples. The band absorbance ratios of A₁₁₇₂/A₁₁₂₆, A₁₄₅₆/A₁₄₀₃, and A₂₉₂₅/A₂₉₅₇ were significantly increased, whereas the A₁₆₅₂/A₁₅₄₁ ratio was decreased in the PCR of the stratum corneum and non-stratum corneum. Baseline changes from 4000 to near 1737 cm^− 1 were observed in the spectra of the electrically injured skin samples, which were interpreted in terms of the pathological process involved in electrical injury. FTIR-MSP presents a useful method to provide objective spectral markers for the assisted diagnosis of electrical marks.     

Determination of the sequence of intersecting lines from laser toner and seal ink by Fourier transform infrared microspectroscopy and scanning electron microscope / energy dispersive X-ray mapping

The aim of this study was to verify that the combination of Fourier transform infrared microspectroscopy and scanning electron microscope / energy dispersive X-ray mapping could be applied to line intersection problems. The spectral data of red seal ink, laser toner and their intersections, such as peak location and peak intensity, were described. Relative peak height ratios of different chemical components in intersecting lines were used to distinguish the sequences. Energy dispersive X-ray mapping characteristics of intersecting areas were also detailed. The results show that both the laser toner and the seal ink appear on the surface of intersections, regardless of the sequence. The distribution of the two inks on the surface is influenced not only by the sequence of heterogeneous lines but also by diffusion. Fourier transform infrared microspectroscopy and scanning electron microscope/energy dispersive X-ray mapping are able to explore the chemical components and the corresponding elemental distribution in the intersections. The combination of these two techniques has provided a reliable method for sequencing intersecting lines of red seal ink and laser toner, and more importantly, this method may be a basis for sequencing superimposed lines from other writing instruments.     

An examination of the sequence of intersecting lines using attenuated total reflectance-Fourier transform infrared spectral imaging

In this study, the potential of attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectral imaging as a technique to determine the sequence of line crossings was examined. The technique was successful in determining the sequence of heterogeneous line intersections produced using ballpoint pens and laser printers. By imaging at characteristic frequencies, it was possible to form spectral images showing the spatial distribution of the materials. By examining the spectral images from the inks, it was possible to determine whether the ink was above or below the toner. In blind testing, ATR-FTIR spectral imaging results were directly compared to those obtained by eight experienced forensic document examiners using methods regularly employed in casework. ATR-FTIR spectral imaging was shown to achieve a 100% success rate in the blind tests, whereas some incorrect sequence determinations were made by the forensic document examiners when using traditional techniques. The technique was unable to image ink-jet printing, gel pens, roller ball pens, and felt-tip pens, and was also unable to determine the sequence of intersecting ballpoint pen lines.     

Raman Microspectroscopic Mapping: A Tool for Identification of Fused Materials in Fire Debris

Examination of fire debris can provide information about the types of materials which were present at the time of the fire to give insights for fire scene reconstruction and understanding compartment fire dynamics. This paper demonstrates the ability of Raman spectroscopy for material identification postfire in complex situations, such as the production of fused masses during fire dropdown. A validated Raman spectral library is combined with Raman mapping in three fire case studies, to determine the individual materials in the fused masses formed. The case studies accessed material combinations of several common polymers. Raman mapping was carried out on a 10 μm × 10 μm square of the masses. Material identification using this technique ranged from a high of 85% match to a low of 40% match. This work demonstrated that complex masses found in the fire debris can be resolved into the individual material components for identification and spatial distribution.     

Forensic applications of infrared chemical imaging: multi-layered paint chips

This paper examines the potential of infrared chemical (hyperspectral) imaging as a technique for the forensic analysis of automotive paint chips in particular, and multicomponent (e.g., layered) samples in general. Improved sample preparation procedures for the infrared analysis of paint chips are detailed, with the recommendation that where mounting resins are chemically incompatible with the sample, it is better to mount and section the sample in a soft wax from which the sections can be removed and pressed into a KBr disk for transmission analysis. Infrared chemical images of multilayered paint chips have been successfully obtained, with the chief advantage over conventional infrared analysis being that thousands of infrared spectra are collected in a few minutes across the whole sample, at a spatial resolution of around 5 microm. As with conventional infrared spectroscopy, chemical species can be identified from their spectra, but the wealth of information available can be also extracted in a number of different ways that make multicomponent spectral (and hence chemical) comparisons between two samples easy to visualize and understand. In one approach, the infrared chemical images of two paint chips being compared side-by-side can be viewed as a "movie," in which each frame is an intensity map of the two samples at a given wavenumber (frequency) value. In another approach, the spectra (pixels) in the image files are classified into chemically similar groups, resulting in a "cluster" image that makes it possible to simultaneously compare all of the layers in two paint chips. These methods are applicable to other multicomponent samples, and also to other chemical imaging techniques.     

Characterization of Protein Alterations in Damaged Axons in the Brainstem Following Traumatic Brain Injury Using Fourier Transform Infrared Microspectroscopy: A Preliminary Study

Axonal injury contributes greatly to neurological dysfunction following traumatic brain injury (TBI), but current histological diagnostic methods are limited in identifying the pathological profiles of injured axons and unable to provide an objective and accurate quantification. Fourier transform infrared microspectroscopy (FTIRM) has the ability to offer macromolecular bioinformatics of the tissues including biochemical composition and structure by calculating band absorption intensity. In this study, axonal injury in the brainstem of rats with traumatic brain injury at 72 h post‐trauma, which was confirmed with beta‐amyloid precursor protein (β‐APP) immunostaining, was detected with FTIRM technique. The lower intensity of infrared absorbance under the amide I band corresponds strongly to the area of axonal injury, and further analysis of amide I band shows significant differences in protein conformation between injured and normal axons. The findings indicate that using FTIRM technique, the amide I band has potentials to be a infrared spectral marker of axonal injury.     

大鼠死后皮肤傅里叶变换红外光谱变化与死亡时间的关系

目的运用傅里叶变换红外(Fourier transform infrared,FTIR)光谱技术分析大鼠死后15d内背部皮肤的光谱变化,以此推断死亡时间。方法大鼠麻醉后颈椎脱臼处死,置于温度为25℃、湿度为50%的环境中,分别于不同时间点提取其背部皮肤,收集红外光谱数据,并利用机器学习技术对数据进行分析。结果大鼠死后背部皮肤组织光谱吸收峰的峰位未发生明显改变,其强度随死亡时间延长而发生变化;偏最小二乘(partial least squares,PLS)回归构建的死亡时间推断模型决定系数(R2)为0.92,预测均方根误差为1.30 d。根据模型中的变量投影重要性(variable importance for projection,VIP)指标确定推断死亡时间的贡献波段为1760~1700cm-1、1660~1640cm-1、1580~1540cm-1和1460~1420cm-1。结论应用FTIR技术检测大鼠死后皮肤组织的光谱学改变,为死亡时间推断提供了一种新的思路。     

TOF‐SIMS Analysis of Red Color Inks of Writing and Printing Tools on Questioned Documents

Time‐of‐flight secondary ion mass spectrometry (TOF‐SIMS) is a well‐established surface technique that provides both elemental and molecular information from several monolayers of a sample surface while also allowing depth profiling or image mapping to be performed. Static TOF‐SIMS with improved performances has expanded the application of TOF‐SIMS to the study of a variety of organic, polymeric, biological, archaeological, and forensic materials. In forensic investigation, the use of a minimal sample for the analysis is preferable. Although the TOF‐SIMS technique is destructive, the probing beams have microsized diameters so that only small portion of the questioned sample is necessary for the analysis, leaving the rest available for other analyses. In this study, TOF‐SIMS and attenuated total reflectance Fourier transform infrared (ATR‐FTIR) were applied to the analysis of several different pen inks, red sealing inks, and printed patterns on paper. The overlapping areas of ballpoint pen writing, red seal stamping, and laser printing in a document were investigated to identify the sequence of recording. The sequence relations for various cases were determined from the TOF‐SIMS mapping image and the depth profile. TOF‐SIMS images were also used to investigate numbers or characters altered with two different red pens. TOF‐SIMS was successfully used to determine the sequence of intersecting lines and the forged numbers on the paper.     

TFD-2纸张手印快速显现系统的应用

目的介绍一种利用特殊的红外热成像技术显现常见纸张上汗潜手印的新方法。方法利用英国Foster4-Freeman公司生产的TFD-2纸张手印快速显现系统,通过特殊的红外热成像技术,使汗潜手印呈现强烈荧光,从而显现手印。结果红外热成像方法处理后,汗潜手印在特种激发光（带宽为450nm-510nm）激发下显出较强的橙色荧光;持续处理后,汗潜手印在自然光下呈棕褐色,并在短波紫外光源（254nm）激发下也可显出清晰连贯的手印纹线;而且,新鲜和陈旧手印均有较好的显现效果。结论TFD-2纸张手印快速显现系统显现纸张上汗潜手印的方法,具有操作简单、快速安全、无需化学试剂、显现效果明显的特点,适合推广使用。