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。     

STR基因座与Amelogenin的峰面积比在DNA降解评估中的应用

目的研究DNA降解过程中STR基因座与性别基因座Amelogenin(AMEL)峰面积比(STR/AMEL)的变化规律,探讨STR/AMEL值在评估DNA降解程度中的应用。方法取人体髂腰肌组织抽提DNA,分析DNaseⅠ酶人工降解后STR/AMEL值(Penta E/AMEL、Penta D/AMEL、FGA/AMEL)的变化,并分析室外环境自然降解的髂腰肌组织中三者比值的变化。以降解时间为自变量(x),STR/AMEL值为因变量(y),进行回归曲线分析,建立两种条件下三组曲线方程。结果人工降解及自然降解条件下STR/AMEL值与降解时间均呈负相关,一元三次方程能够较好地模拟STR/AMEL值随降解时间的变化规律。人工降解条件下,R~2均大于0.99;自然降解条件下,R~2均大于0.86。结论 STR/AMEL值(Penta E/AMEL、Penta D/AMEL、FGA/AMEL)与DNA降解程度呈负相关,有望应用于DNA降解程度的评估。     

电烧伤皮肤金属元素的测定

本实验系用220V交流电源和直径2.0mm紫铜线为接触电极,在新鲜尸体腹部皮肤上做电烧伤实验。用原子吸收分光光度计对电烧伤皮肤中铜元素含量进行测定。结果表明电烧伤皮肤铜元素含量最高可达137.90μg/g。经10%福尔马林溶液固定40天以上的电烧伤皮肤铜元素含量有昕降低,但仍较正常皮肤含量为高。电烧伤皮肤铜元素含量以电流斑处为最高。本实验为电烧伤皮肤金属元素的定性与定量分析,检材的提取和处理,提供了一个较好的方法,有利于判定案件的性质和确定接触电极的金属种类。     

鱼塘水中微量铜的原子吸收检验

采用原子吸收检验测定因投放铜盐导致鱼大批死亡的鱼塘水中的微量铜以空白鱼塘水为对照,铜标准液做标准曲线,方法简单,结果准确可靠,是该类案件检测的较好方法之一.     

一种改进的红外图像非均匀性校正算法

针对两点多段线性校正法校正因子推导过于简单的缺点,提出一种改进算法。这种算法对增益系数和偏移系数重新进行推导,弥补了两点多段校正法中由于校正因子推导带来结果值偏大的不足,并对算法进行了仿真。     

国际直接投资理论与FDI吸收能力渊源

20世纪80年代以来对FDI吸收能力的研究日益突出,关于FDI吸收能力的研究渊源于国际直接投资理论。产生于20世纪60年代的国际直接投资理论基本上沿着两条思路展开:一是研究国际直接投资形成的原因、去向及其决定,简称为FDI决定理论;二是考察国际直接投资对东道国经济的影响及其政策激励,简称为FDI影响理论。     

The discrimination potential of ultraviolet-visible spectrophotometry, thin layer chromatography, and Fourier transform infrared spectroscopy for the forensic analysis of black and blue ballpoint inks

The knowledge of the discriminating power of analytical techniques used for the differentiation of writing inks can be useful when interpreting results. Ultraviolet-visible (UV-VIS) spectrophotometry, thin layer chromatography (TLC), and diffuse reflectance Fourier transform infrared spectroscopy (FT-IR) were used to examine a population of 21 black and 12 blue ballpoint writing inks. Based on corroborative results of these methods, the discrimination power for UV-VIS, TLC, and FT-IR was determined to be 100% and 98% for the black and blue inks, respectively. Generally, TLC and UV-VIS can be used to differentiate the colorant components (i.e., dyes and some pigments) found in inks. As FT-IR can be utilized to identify some of the noncolorant components, it was determined to be an excellent complementary technique that can be implemented into an analytical scheme for ink analysis.     

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.     

Investigation of Postmortem Absorption and Redistribution After the Application of a Fentanyl Patch

Fentanyl deaths have increased with availability of transdermal patches. Interpretation of postmortem fentanyl levels may be complicated by postmortem redistribution and absorption of fentanyl from a patch. We applied an unused 100‐μg/h fentanyl patch onto the lower abdomen of a decedent with no premortem fentanyl exposure. Ocular fluid, blood, and urine were collected prior to placement, and the decedent was refrigerated for 23 h. Prior to the autopsy, urine, subcutaneous tissue under the patch, and samples from the same anatomic sites were obtained. We observed no fentanyl in any postpatch placement samples (LOD: 0.1 ng/mL for blood and vitreous fluid, 1.0 ng/mL urine, 2.0 ng/g for tissues). Although we observed no postmortem absorption of fentanyl, this was only a single case; therefore, we recommend that patches be removed after receipt of a cadaver before initiation of an autopsy, with the location of removed patch documented.