To evaluate the utility of smaller sample sizes when assessing dental maturity curves for forensic age estimation

Dental maturation and chronological age estimation were determined from 144 healthy Western Australian individuals aged 3.6-14.5 years. The results were compared with Farah et al.'s previous study which comprised a larger heterogeneous sample of Western Australian individuals (n = 1450). Orthopantomograms were analyzed with the application of Demirjian and Goldstein's 4-tooth method based on eight stages of dental mineralization. Analysis of variance revealed no significant differences in dental maturity scores in each age group among the males in both studies; similar results were seen in the females. Paired t-tests showed no statistical significance overall between chronological and estimated ages for the males in our sample (p = 0.181), whereas the females showed significant differences (p < 0.001). Our results show that smaller samples may be used when assessing dental maturity curves for forensic age estimation.     

生物试样中苯巴比妥药物的超临界流体萃取及气相色谱法检验

超临界流体萃取技术(SFE)作为一种新的前处理技术,在毒物分析领域的应用中显示了很大的优越性。通过一种离线超临界流体萃取、气相色谱直接测定生物试样中苯巴比妥药物的方法,在优化操作条件下,其回收率可达89.98%以上。整个实验操作分析时间少于40分钟,具有速度快、效率高、无毒、不污染环境等特点。     

Serum strontium estimation as a diagnostic criterion of the type of drowning water

The estimation of serum strontium in rabbits before and after death by drowning, in soft or hard water, or by barbiturate intoxication is highly promising as a method in medicolegal practice. It not only diagnoses drowning but also indicates the type of drowning water. Atomic absorption spectrophotometry is a good method for the estimation.     

Gc蛋白的分离纯化

本文报道Gc蛋白的分离与纯化.人血浆经DEAE-Sephadex-A50, Sephadex G100和DEAE-Sephadex-A50三次柱层析即可获得纯化Gc.纯化Gc经PAGE, SDS-PAGE和免疫电泳等证明,其纯度和特异性均符合要求.     

接触DNA在法医实践中的应用研究进展

人体在接触物体后,会在其表面留下少量接触DNA。对接触DNA的检验是目前法医DNA检验技术的热点和难点。接触DNA的检验成功率差异较大,受各环节多重因素影响。影响接触DNA检验成功率的主要因素有接触DNA检材的准确发现、接触DNA的提取与纯化以及扩增策略的选择和结果分析等。本文详述了接触DNA检验过程的进展及研究展望。     

生物检材中乌头碱的LC-MS/MS快速分析

目的应用高效液相色谱-质谱法对生物检材中乌头生物碱等有毒成分进行快速分析。方法取全血样品经乙腈-甲醇(5:1 v/v)提取,使用Agilent Zorbax SB C18(2.1 mm×50 mm,1.8μm)色谱柱,以0.1%甲酸溶液-乙腈(60:40 v/v)为流动相等度洗脱。在多反应监测模式下测定全血样品中乌头生物碱等有毒成分。结果乌头碱、次乌头碱和中乌头碱的保留时间为0.73 min、0.77 min和0.63 min;用于定量分析的离子对分别为m/z 646.4→586.4(乌头碱)、616.1→556.5(次乌头碱)和632.4→572.1(中乌头碱)。乌头碱在0.1~250 ng/m L内线性关系良好,相关系数(r)≥0.9987,最低检出限0.1ng/m L,精密度考查其变异系数(CV)5.42%(n=6),血液中乌头碱提取回收率不小于90%。结论本文建立的高效液相色谱-质谱法快速、简便、灵敏,适用于天然药毒物检验。     

论强制采样侦查手段的法制化

强制采样作为一种特殊的侦查手段,在刑事案件的侦查中发挥着不可忽视的作用。考察我国现阶段有关强制采样的相关规定以及在进行强制采样侦查过程中所出现的问题,我们不难发现强制采样侦查手段的实施和法律规制已出现了相当棘手的问题。结合域外的司法实践,我们只有对强制采样侦查手段予以法定化、程序化、制度化,才能使其更好地发挥作用,更有力地打击各种刑事犯罪活动。     

Nitrous Oxide Determination in Postmortem Biological Samples: A Case of Serial Fatal Poisoning in a Public Hospital*

Abstract: In a public hospital, eight cases of fatal poisoning by nitrous oxide (N₂O) occurred under oxygen administration, due to an erroneous swapping of the lines in the gas system. The aim of the study was to clarify the factors involved in asphyxia by characterizing gases from different lines and measuring N₂O concentrations in postmortem biological samples from bodies exhumed. Analyses carried out on the gas system confirmed the erroneous substitution of O₂ line with N₂O and air line with O₂. Consequently, high N₂O amounts were revealed in several tissues and gaseous biological samples. All specimens were analyzed by headspace gas chromatography technique. A rigorous quantitative analysis was possible only in blood (11.29–2152.04 mg/L) and urine (95.11 mg/L) and in air samples from stomach and trachea (from 5.28 to 83.63 g/m³). This study demonstrates that N₂O can be detected in biological samples even 1 month after death.     

侦查机关强制采取物证比对样本的必要性及合法化路径研究

本文讨论了刑事侦查中强制采取物证比对样本的必要性以及立法规制这种强制活动的必要性,探究了强制采样的合法化路径。认为法律应明确侦查机关有权依照必要性原则、适当性原则和比例原则在侦查中强制采取物证比对样本,并就强制采样的主体、对象、程序等问题作出具体规定,否则,就有可能侵犯相关人员的基本人权。     

A fast ultrasound-assisted extraction procedure for trace elements determination in hair samples by ICP-MS for forensic analysis

An ultrasound-assisted extraction method is proposed for the determination of trace elements in hair samples by inductively coupled plasma-mass spectrometry (ICP-MS) for forensic investigation. Prior to analysis, 25 mg of hair samples were accurately weighed into (15 mL) conical tubes. Then, 2 mL of 20% HNO₃ is added to the samples, sonicated at 2 min (50 W, 100% amplitude), and then further diluted to 10 mL with Milli-Q water. Resulted diluted slurries are centrifuged and the analytes are directly determined in the supernatant. Calibrations against aqueous solutions were carried out with rhodium as internal standard. The method was successfully applied for the extraction of Al, As, Ba, Be, Cd, Co, Cr, Cu, Mn, Pb, Tl, U, V and Zn with a method detection limit (3 s, n = 20) of 0.1, 0.4, 0.2, 0.09, 0.08, 0.04, 0.1, 2.9, 1.0, 0.9, 0.04, 0.05, 0.1 and 4.2 ng/g, respectively. Method accuracy is traceable to Certified Reference Materials (CRMs) 85 and 86 human hair from the International Atomic Energy Agency (IAEA). Additional validation data are provided based on the analysis of hair samples from the trace elements intercomparison program operated by the Institut National de Sante’ Publique du Quebec, Canada. The proposed method is very simple and can be applied for forensic purposes with the elimination of sample digestion step prior to analysis. Then, a considerable improvement in the sample throughput is archived with the use of the proposed method.