GC/MS研究海洛因代谢物在吸毒者体内的分布

应用GC／MS－SIM测定了海洛因代谢物吗啡在两例海洛因延缓死亡者的体内分布,并分析了收集到的7例案子的毛发（头发、腋毛和阴毛）中6-单乙酰吗啡和吗啡含量。生物检材和毛发经酸水解、提取、醋酸酐或双（三甲基硅基）三氟乙酰胺（BSTFA）衍生化,然后进行GC／MS-SIM分析。结果表明尿、胆汁和肝脏是判定死者是否曾使用海洛因的最佳检材;毛发分析与生物检材相比有其独特的优点,可提供数月甚至数年的用药情况。为公安司法机关打击吸毒、惩治犯罪提供更可靠、有效的证据。     

Chemical composition and structure of the microcrystals formed between silver(I) and gamma-hydroxybutyric acid and gamma-hydroxyvaleric acid

This study examined microcrystals formed by silver with gamma-hydroxybutyric acid (GHB) and gamma-hydroxyvaleric acid (GHV), the five-carbon analog of GHB, in the presence of silver, copper, and lanthanide nitrates. Distinct microcrystals formed with silver (+1) and lanthanum (+3) ions but not with the copper (+2) ions. The crystals formed with GHB were distinctly different than those formed with GHV and in all cases, the drug microcrystals were easily distinguishable from reagent crystals. X-ray diffraction analysis provided definitive structure for the microcrystals. The morphological differences between the silver-GHB and silver-GHV crystals were characterized using simple measurements such as size and angles provided by image recognition software. The utility of the test for casework was demonstrated using spiked beverage samples.     

Concentration of carbon monoxide (CO) in postmortem human tissues: effect of environmental CO exposure

We studied how carbon monoxide (CO) is distributed within the human body through quantitation of CO concentrations in postmortem tissue samples from fatalities including possible CO exposure. Stored, frozen tissues were diced, sonicated in water, and 0.01-8.0 mg wet weight (ww) tissues were incubated with sulfosalicylic acid in CO-purged, septum-sealed vials. CO released into the headspace was quantitated by reduction gas chromatography. Mean tissue CO concentrations (pmol/mg ww) from subjects diagnosed to have no known CO exposure (control, N=14), died from fire (N=13), and CO asphyxiation (N=7), respectively, were: adipose (2;13;9), brain (3;13;65), muscle (15;97;297), heart (30;99;371), kidney (22;432;709, lung (54;690;2638), spleen (73;1366;3548), and blood (162;2238;5070). Carboxyhemoglobin concentrations were 1.4%, 25.2%, and 69.1% of total hemoglobin, respectively. We conclude that measurements of CO concentration in a variety of tissues can be used as markers for the degree of exogenous CO exposure and the identification of possible causes of death.     

死后离体人肝组织的激光共聚焦显微拉曼光谱分析

目的观察和探讨人死后肝组织细胞激光共聚焦显微拉曼光谱的变化规律及其与死亡时间的关系。方法离体肝组织于死后48～72h内每隔4h提取样品,采用激光共聚焦显微拉曼光谱技术进行检测。观察800cm-1～3 200cm-1范围内检测样本特征峰的变化,指认其对应的化学基团,选择强度比值I1094/I2923作为响应值,并进行统计学计算。结果在48～72h内,随时间的延长,肝组织细胞主要散射峰峰位无明显变化,而其峰强度有明显差异;与核酸有关的峰（1 094cm-1）强度随时间推移有明显下降;与脂类有关的峰（1 454cm-1、2 923cm-1）强度变化不明显;各相对峰强（I1094/I2923）随死亡时间的推移而减小,并得到回归方程（r=0.914）。结论人死后肝组织细胞DNA降解随死亡时间延长呈下降趋势,I1094/I2923值与PMI呈负线性关系。激光共聚焦显微拉曼光谱技术有望成为推断死亡时间的检测方法。     

PrP基因在金黄地鼠淋巴和外周组织中表达水平的动态检测

利用实时荧光定量RT-PCR技术,构建了标准重组质粒,制备了标准曲线,对不同年龄金黄地鼠腹股沟浅淋巴结、脾、心、肝、肺和肾提取总RNA,反转录后进行PrP基因的表达定量。结果发现,淋巴组织呈现高的表达量,外周组织的表达量比较低;不同组织在不同年龄出现表达高峰。     

玻璃刺创形态学特点的初步研究

目的研究玻璃刺创的形态学特点。方法分别用3个厚度为0．31cm带尖状突起的啤酒瓶残端及3块厚度为0．29cm有尖的普通窗玻璃碎片按设定的不同方向刺击带皮猪肉组织,重复此过程3次,形成198例创口,观察、编号、拍照、测量各创口。结果198例创口的整体形态可分为5种类型,即“工”型、“”型、“”型、“上”型与“一”型,各型在不同刺击方向的分布上存在差异,其中前4种为主要类型,共约占总数的93％,其共同点为在损伤的中部出现了一段与损伤整体走向垂直的创口,啤酒瓶残端所致垂直创口的长度为0．31±0．Olcm（x±s）,窗玻璃碎片所致垂直创口的长度为0．29±0．Olcm（x±s）。结论损伤中部有与损伤整体走向垂直的短创口是玻璃刺创中易出现的一种形态学特点,垂直创的长度与致伤玻璃的厚度具有一致性。     

大鼠死后肝脏磷酸果糖激酶-2含量的变化

目的 分析不同死亡时间和死亡原因大鼠肝脏组织内磷酸果糖激酶-2(PFK-2)含量的变化.方法 大鼠105只随机分为三组,以不同方式(失血、窒息、断颈)处死.分别于死后0、1、2、4、8、12和24h取大鼠肝脏组织,免疫组化和图像分析技术测定大鼠PFK-2变化.结果 三组不同死亡原因大鼠肝脏组织内PFK-2的含量随死亡时间延长呈规律性减弱趋势.结论 大鼠肝脏组织内PFK-2的变化可以反映死亡时间的变化趋势.     

An unusual case of thermal injuries with a hot glue gun: Deliberate self-harm or maltreatment?

Assessing injuries in forensic medicine casework, examiners are often confronted with the question of self-infliction versus third parties' influence, respectively, deliberate self-harm versus maltreatment. We report the case of a 40-year-old male who presented with numerous partially healed thermal injuries of different age. These burns were shaped like capital letters and little circles, which were arranged in lines in a regular form. The lesions were found on the whole body with exclusion of face, genitals, hands and feet. Furthermore, four bitemarks at the right shoulder were noted. Investigations revealed that the man had been abused by his 25-year-old wife (presumably a borderline personality disorder patient) for at least 1 year. In addition to another series of abuses, the woman may have inflicted the shaped burns with a hot glue gun as punishment for breaking certain "rules" she had established. When assessing injuries of patients in forensic medicine, several considerations regarding etiology have to be taken into account. In principle, the victim's testimony, the anamnesis, the police investigation results and the findings from the forensic physical examination have to be balanced against each other. The injury pattern in the present case showed contradictory single characteristics both of deliberate self-harm and of maltreatment. After forensic analysis, it was assessed as injuries inflicted by an assistant with the patient's consent.     

黄牛足螨的形态学观察

采用光学显微镜和扫描电子显微镜对采自四川黄牛的足螨进行了形态学观察和测量。结果表明:各发育阶段的足螨均呈长椭圆形,幼螨大小为(160.9±26)μm×(124.7±17)μm,3对足;雌性若一螨大小为(210.8±29)μm×(160.1±22)μm;雌性若二螨大小为(235.2±18)μm×(183.1±16)μm,体末具有圆柱形突出物1对;雌性成螨大小为(311.4±27)μm×(213.3±21)μm;雄性若螨大小为(216.1±18)μm×(168.2±14)μm;雄性成螨大小为(245.7±24)μm×(191.0±21)μm。其中雄性足螨末端突出物分2节,突出物上竹片状刚毛(Spatulate setae)的长度为168~200μm,最外侧刚毛的平均长度为50μm左右,根据其形态学特征鉴定为德州足螨。     

Striation Density for Predicting the Identifiability of Fired Bullets with Automated Inspection Systems*

Abstract: Automated firearms identification systems will correlate a reference bullet with all evidence bullets without a selection procedure to exclude the bullets having insufficient bullet identifying signature. Correlations that include such bullets increase the workload and may affect the correlation accuracy. In this article, a parameter called striation density is proposed for determining and predicting bullet identifiability. After image preprocessing, edge detection and filtering techniques are used to extract the edges of striation marks, the resulting binary image distinctly shows the amount and distribution of striation marks. Then striation density is calculated for determining the quality of images. In the experiment, striation densities for six lands of 48 bullets fired from 12 gun barrels of six manufactures are calculated. Statistical results show strong relation between striation density and identification rate. It can provide firearms identification systems with a quantitative criterion to assess whether there are sufficient striae for reliable bullet identification.