纤维联接蛋白的析出与大鼠皮肤早期损伤的时间关系

采用免疫组化(PAP)方法,检测大鼠皮肤损伤区的FN,发现在生前创伤后15min,创壁FN即呈明确阳性;随着伤后经历时间的延长,创壁FN逐渐增多,并滑创壁呈条带状沉积;而在死后5min的创伤,创壁FN则呈阴性。本文为区别生前与死后皮肤创伤提出了一种新的方法。     

家兔玻璃体液HBDH、LDH活性变化与PMI相关性的研究

目的 寻找一种推断PMI的新方法。方法 应用全自动生化检测仪(用比色法)检测家兔死后0-54小时玻璃体液内羟丁酸脱氢酶(HBDH)、乳酸脱氢酶(LDH)在两组温度下(25-30℃:10-15℃)的失活情况。结果 两种酶的活性在死后一定时间内各出现一个平台期,平台期后两酶的活性迅速下降,低温组在死亡54小时后活性几乎为零,高温组在死亡48小时后活性几乎为零。经统计学分析得知死后两种酶活性与PMI之间有显著的负相关性(P<0.05)。结论 在0-54小时内依据其各自的回归方程将可以大致地推断PMI,依据两种酶活性的多元回归方程可以较准确地推断PMI。     

Application of fluorescence lifetime imaging (FLIM) in latent finger mark detection

Fluorescence lifetime imaging (FLIM) in frequency domain enables the mapping of the spatial distribution of fluorescence lifetimes of a specimen. It has been extensively applied in biology. In this paper, a theoretical analysis for the fluorescence lifetime determination of latent finger mark samples is described, which is followed by the feasibility study of using FLIM in frequency domain for latent finger marks detection. Preliminary experiments are carried out with latent finger marks treated with a fluorescent powder on two different substrates. The resulting fluorescence lifetime image of finger mark revealed a good contrast, and was able to detect the latent finger marks clearly.     

大鼠死后心肌细胞DNA含量与死亡时间关系的进一步研究

目的研究机体的细胞核内DNA含量与死亡时间的关系。方法本实验通过计算机图像系统,选择核面积、积分光密度等7种参数,研究了15只大鼠心肌细胞在死后25～49h细胞核DNA含量的变化规律。结果心肌细胞DNA含量测定适合相对较长死亡时间的推断。结论应用计算机图像分析技术测量机体死后心肌细胞DNA含量将有可能成为推断死亡时间精确、客观的新方法。     

Smartphone Image Acquisition During Postmortem Monocular Indirect Ophthalmoscopy

The medical usefulness of smartphones continues to evolve as third‐party applications exploit and expand on the smartphones’ interface and capabilities. This technical report describes smartphone still‐image capture techniques and video‐sequence recording capabilities during postmortem monocular indirect ophthalmoscopy. Using these devices and techniques, practitioners can create photographic documentation of fundal findings, clinically and at autopsy, without the expense of a retinal camera. Smartphone image acquisition of fundal abnormalities can promote ophthalmological telemedicine—especially in regions or countries with limited resources—and facilitate prompt, accurate, and unbiased documentation of retinal hemorrhages in infants and young children.     

Drunk Person Screening using Eye Thermal Signatures

Temperature distribution on the eyes of drunk persons is studied by means of thermal infrared images. The sclera and the iris are of the same temperature for the sober person, while for the intoxicated person, the sclera temperature increases. Consequently, only the thermal images from the drunk persons are necessary for intoxication screening. Forty‐one participants drank in a controlled alcohol consumption procedure. Their breath alcohol concentration was above the threshold of 0.2 mg/L of exhaled air, which corresponds to about 0.5 mg of alcohol per cubic centimeter of blood. Histogram modification algorithms were employed to prove that for 36 among the 41 intoxicated persons, the sclera becomes hotter. The Student t‐test verified with over 99% confidence the drunk discrimination capabilities of the procedure. The forensic science potential contribution of the method is that face infrared imagery is available to the authorities for supporting intoxication in case of criminal actions.     

Detection of Acetaminophen–Protein Adducts in Decedents with Suspected Opioid–Acetaminophen Combination Product Overdose

Acetaminophen overdose is a leading cause of drug‐induced liver failure in the United States. Acetaminophen–protein adducts have been suggested as a biomarker of hepatotoxicity. The purpose of this study was to determine whether protein‐derived acetaminophen–protein adducts are quantifiable in postmortem samples. Heart blood, femoral blood, and liver tissue were collected at autopsy from 22 decedents suspected of opioid–acetaminophen overdose. Samples were assayed for protein‐derived acetaminophen–protein adducts, acetaminophen, and selected opioids found in combination products containing acetaminophen. Protein‐derived APAP‐CYS was detected in 17 of 22 decedents and was measurable in blood that was not degraded or hemolyzed. Heart blood concentrations ranged from 11 ng/mL (0.1 μM) to 7817 ng/mL (28.9 μM). Protein‐derived acetaminophen–protein adducts were detectable in liver tissue for 20 of 22 decedents. Liver histology was also performed for all decedents, and no evidence of centrilobular hepatic necrosis was observed.     

外温变化下小鼠肝细胞18s rRNA降解与死亡时间关系研究

目的探讨在外界环境温度变化条件下,小鼠肝细胞18s rRNA降解与死亡时间的关系。方法小鼠断颈处死后置于10℃、15℃、20℃、25℃、和30℃温度下保存;从死后6h至72h,每6h分别提取肝细胞组织中总RNA。利用实时荧光定量PCR检测18s rRNA循环阈值(Ct值)的变化。应用插值函数进行分析拟合,建立死亡时间推断方程。结果各温度组Ct值随死亡时间延长均呈上升趋势,对所得数据进行插值拟合,得到一定温度变化区间内(10℃~30℃),Ct值变化与PMI关系的三元五次曲面方程:f(x,y)=-426.9+30.82x+44.48y-1.297x~2-1.837xy-1.388y~2+0.034 38x~3+0.038 17x~2y+0.038 67xy~2+0.028 77y3-0.000 612 9x~4-3.897e~(-7)x~3y-0.001 223x~2y~2+0.000256 6xy3-0.000 537 4y~4+3.606e~(-6)x~5-2.846e~(-6)x~4y+1.009e~(-5)x~3y~2-3.439e~(-6)x~2y3-2.556e~(-7)xy~4+2.664e~(-6)y~5(r2=0.999 4)。结论在外界温度变化条件下,小鼠肝细胞18s rRNA降解与死亡时间关系符合三元五次方程分布,利用插值函数拟合的方法可在外界环境温度变化条件下进行死亡时间推断。     

地西泮及去甲地西泮在大鼠体内的死后再分布研究

目的观察地西泮及其主要代谢物去甲地西泮在大鼠体内的死后再分布特点。方法大鼠24只,随机分成8组,以安定90 mg/kg灌胃,2 h后脱颈椎处死,左侧卧位,分别置于室温(10℃)条件下,于死后不同时间(0h、2h、4h、8h、12h、24h、48h、96h)取心、肝、脾、肺、肾、大脑、肌肉,固相萃取、高效液相色谱法检测其中地西泮及其主要代谢物去甲地西泮的含量。结果地西泮及其主要代谢物去甲地西泮在染毒处死大鼠内各时间点、各脏器都有分布并呈现出一定的规律性。结论地西泮及其主要代谢物去甲地西泮在染毒处死大鼠内可发生死后再分布。     

猪肋软骨和肋骨的ATR-FTIR光谱变化与死亡时间的关系

目的应用衰减全反射傅里叶变换红外(attenuated total reflection-Fourier transform infrared,ATRFTIR)光谱技术分析长白猪死后肋软骨和肋骨组织随死亡时间推移的化学降解过程,为死后较长时间段内推断死亡时间提供可行的新途径和方法。方法猪放血处死后取肋软骨和肋骨离体置于20℃环境,后每72 h提取部分组织样本,进行ATR-FTIR光谱分析,并与对应死亡时间点进行相关性分析。结果随死亡时间的延长,肋软骨与肋骨FTIR的主要吸收峰峰位没有发生明显变化,而其部分峰强比出现了不同时序性的变化趋势,并与死亡时间存在良好的相关性,肋软骨较肋骨组织有更好的时序性。结论应用ATRFTIR光谱技术发现死后猪肋软骨和肋骨组织光谱学变化存在一定的规律性,有望成为基于光谱学推断死亡时间的一种新途径。