不同死因大鼠死后不同时间红细胞溶血速度比较

目的观察不同死亡原因大鼠尸体血液中红细胞溶血速度的变化规律,为死亡原因的法医学推断提供新思路。方法 40只SD大鼠随机分为4组,分别以断髓、置于99%CO的空间、高坠、勒颈方式处死后,取各组大鼠右心室血液,于死后即刻（0h）、8h、16h、24h、32h、40h、48h、56h、64h、72h,采用显微镜数码图像法进行全血红细胞计数（CBC）,并对组内和组间数据进行统计学比较分析。结果 4组血液红细胞数量在死后即刻至72h期间,均随时间的延长因溶血而减少。其中0~16h,各组溶血速度无明显差异（P〉0.05）;16~48h,速度加快,溶血速度以CO中毒组（88.50±25.99）%最快,其次为高坠（69.33±29.52）%和断髓组（48.78±3.17）%,机械性窒息组（41.90±9.61）%最慢,组间比较具有显著性差异（P〈0.05）;56h后,溶血速度再次减慢,至72h机械性窒息组仍有少量红细胞存在。结论 4组不同死因大鼠死后不同时间红细胞计数均减少,各组间差异具有统计学意义,其变化特征可为死亡原因的推断提供新的思路。     

氨基比林血痕预试验处理血痕后样本的DNA定量

目的：探讨氨基比林血痕预试验处理血痕后样本DNA含量的变化及对STR分型检测的影响。方法10名健康无关个体EDTA抗凝血液制成滤纸血痕,氨基比林血痕预试验检测,按试验后血样干燥保存时间分30 min、1 h、3 h、6 h、12 h、24 h共6个实验组,并采用磁珠法、QIAcube DNA纯化法、Chelex-100法三种方法提取样本DNA,应用荧光定量PCR检测样本DNA含量,PCR-STR荧光技术进行STR分型。结果提取方法相同时,氨基比林血痕预试验后血样随干燥保存时间的延长,样本DNA含量呈逐渐降低的趋势。保存时间相同时,不同DNA提取方法间,样本DNA含量差异也有统计学意义。90.56%样本均可获得16个STR基因座明确分型。结论氨基比林血痕预试验对血痕样本DNA有损伤,24 h内多可获有效STR分型。磁珠法提取样本DNA进行STR分型,效果最好。     

基于MRI的中国汉族成人颅面径线测量与分析

目的通过MRI和VGStudio MAX 2.2软件对中国汉族成人颅面相关径线进行测量,并分析其与性别、年龄、身高以及体重的关系。方法按颅面标志点设定4条径线。A径线：在正中矢状面上颏下点至头顶点的最大直线距离;B径线：在正中矢状面上发际点至后头点的最大直线距离;C径线：在水平面上左、右外眼点间的最大直线距离;D径线：在冠状面上左、右侧颧点间的最大直线距离;用VGStudio MAX 2.2软件对MRI图像数据进行三维重建,直接用软件的测量工具对颅面的相关径线进行测量,并用SPSS 16.0进行分析。结果 A、B、C、D径线的均值分别为（237.54±8.63）mm、（173.07±8.28）mm、（89.58±4.46）mm、（127.34±8.16）mm,与性别有着显著性差异（P〈0.01）;其中A、C、D径线与身高,A、D径线与体重,C径线与年龄,均存在明显的直线相关关系。结论中国汉族成人颅面径线A、B、C、D均存在明显的性别差异;且A、C、D径线与身高,A、D径线与体重,C径线与年龄,均存在明显的直线相关关系。     

Postmortem Distribution of 3‐Beta‐Hydroxybutyrate

The concentrations of 3‐beta‐hydroxybutyrate (3HB) in femoral blood, urine, vitreous humor as well as pericardial and cerebrospinal fluids were retrospectively examined in a series of medico‐legal autopsies, which included cases of diabetic ketoacidosis, hypothermia fatalities without ethanol in blood, bodies presenting mild decompositional changes, and sudden deaths in chronic alcoholics. Similar increases in 3HB concentrations were observed in blood, vitreous, and pericardial fluid, irrespective of the cause of death, suggesting that pericardial fluid and vitreous can both be used as alternatives to blood for postmortem 3HB determination. Urine 3HB levels were higher than blood values in most cases. Cerebrospinal fluid 3HB levels were generally lower than concentrations in blood and proved to be diagnostic of underlying metabolic disturbances only when significant increases occurred.     

Using Spatial,Temporal and Evidence‐status Data to Improve Ballistic Imaging Performance

Firearms identification imaging systems help solve crimes by comparing newly acquired images of cartridge casings or bullets to a database of images obtained from past crime scenes. We formulate an optimization problem that bases its matching decisions not only on the similarity between pairs of images, but also on the time and spatial location of each new acquisition and each database entry. The objective is to maximize the detection probability subject to a constraint on the false positive rate. We use data on all cartridge casings matches detected in Israel during 2006–2008 to estimate most of the model parameters. We estimate matching accuracy from two different studies and predict that the optimal use of extraneous information would increase the detection probability from 0.931 to 0.987 and from 0.707 to 0.844, respectively. These improvements are achieved by favoring pairs of images that are closer together in space and time.     

CT‐Guided,Minimally Invasive,Postmortem Needle Biopsy Using the B‐Rob II Needle‐Positioning Robot

CT‐guided, minimally invasive needle biopsy techniques can be used to retrieve tissue or body fluid samples for histologic tissue diagnoses in forensic investigations. The purpose of this study was an evaluation of CT‐guided needle‐positioning robot B‐Rob II. To operate under CT guidance, we adopted the B‐Rob II robotic needle placement system and its workflow. The accuracy and speed of the procedure were tested on a gelatin phantom in a series of 21 biopsies. We achieved an average needle placement accuracy of 1.8 mm (±1.1 mm) using robotic assistance. The procedure required an average of 2 min 21 s. The needle placement accuracy for minimally invasive needle biopsies using the B‐Rob II biopsy robot is sufficiently accurate and fast for forensic postmortem examinations of focal organ changes. Further tests will be performed to test the feasibility of the robot for performing biopsies of focal organ changes in human bodies.     

Pneumomediastinum and Soft Tissue Emphysema in Pediatric Hanging

Postmortem computed tomography (CT) is increasingly being used as a tool in forensic pathology. The exact value of postmortem imaging in detecting specific conditions has not yet been established, but in specific cases, it can be used as a diagnostic tool demonstrating findings that remain undetected during autopsy, as in this case. Pneumomediastinum and soft tissue emphysema were detected with postmortem CT in a 3‐year‐old girl after hanging. It was not found during autopsy. This radiological finding matches 3 adult cases previously described. It is assumed that in this case, the first reported in a child, hanging was the most likely cause as well. In the adult cases, it was interpreted as a vital sign; the person must have been alive to create a pressure gradient causing rupture of the alveoli. This case demonstrates one of the added values of postmortem imaging, the possibility of demonstrating findings that remain undetected during autopsy.     

Comparative Analysis of Insect Succession Data from Victoria (Australia) Using Summary Statistics versus Preceding Mean Ambient Temperature Models

Minimum postmortem interval (mPMI) can be estimated with preceding mean ambient temperature models that predict carrion taxon pre‐appearance interval. But accuracy has not been compared with using summary statistics (mean ± SD of taxon arrival/departure day, range, 95% CI). This study collected succession data from ten experimental and five control (infrequently sampled) pig carcasses over two summers (n = 2 experimental, n = 1 control per placement date). Linear and exponential preceding mean ambient temperature models for appearance and departure times were constructed for 17 taxa/developmental stages. There was minimal difference in linear or exponential model success, although arrival models were more often significant: 65% of linear arrival (r² = 0.09–0.79) and exponential arrival models (r² = 0.05–81.0) were significant, and 35% of linear departure (r² = 0.0–0.71) and exponential departure models (r² = 0.0–0.72) were significant. Performance of models and summary statistics for estimating mPMI was compared in two forensic cases. Only summary statistics produced accurate mPMI estimates.     

Use of Postmortem Temperature Decay Response Surface Plots of Heat Transport in the Human Eye to Predict Time of Death

A finite element heat transfer model of the human eye was previously constructed and applied to experimental postmortem temperature decay curves collected in eyeballs of ten human bodies. The model was applied in the early postmortem period of 0–24 h under conditions of natural convection–radiation. Based upon this previous model, response surfaces for postmortem temperature decay were constructed based upon variable ranges of the natural convective–radiation heat transfer coefficient from 7–13 W/m² K, ambient temperatures of 10–33°C, and times of 0–24 h. Mathematical equations to describe these response surfaces have been developed. This response surface method is demonstrated for use by coroners/medical personnel to estimate time of death from recorded field temperature data collected over a 30‐min period. Sensitivity of the model to small changes in the key variable of ambient temperature is explored. The response surface model is applied to two cases of previously collected experimental eyeball temperature data. This response surface model method is only valid for constant surrounding temperatures, conditions of natural convection, no radiation effects, and postmortem times of 0–24 h.     

人体死亡后血液中生化指标的变化

目的测定人体死亡后血液中生化指标的变化并进行分析。方法收集81例交通事故死亡后尸体锁骨下静脉血样,并采用罗氏cobasc311全自动生化分析仪检测血液中肝功能（ALT、AST、TBIL、DBIL）、肾功能（UA、Cr）、心功能（CK、CK—MB、LDH）、电解质（K＋、Na＋、Cl-）以及葡萄糖（GLU）13项生化指标的变化,采用SPSS17．0统计学软件进行描述性分析。结果生化指标中ALT、AST、CK、CK—MB、LDH、D数值较活体正常参考值高、波动幅度较大。TBIL、DBIL、UA、Cr、Na＋、Cl-、GLU数值相对稳定、波动幅度较小。结论人体死亡后血液生化指标中肝功能、肾功能、心功能、电解质以及葡萄糖等指标易受溶血、自溶等因素影响,表现为生化指标升高明显,尤以酶类为著,且标准差较大。