Evaluation of Purkait's triangle method for determining sexual dimorphism

The identification of sex from the skeleton is an important demographic assessment in medicolegal investigations. Rama Purkait developed a method for estimating sex using measurements from a triangle defined by three points on the proximal end of the femur using skeletal material from Bhopal, India. This method was tested with measurements on 200 Indo-European and African American adult femora from the Terry collection using discriminant function analysis to determine if Purkait's method was valuable for determining sex in Americans. A side-by-side analysis was conducted of Purkait's "triangle method" and the maximum diameter of the femoral head to determine their relative value in assessing sexual dimorphism. In the study sample a single variable from Purkait's method provided 85.5% prediction accuracy, similar to 87% for the head diameter. Combining threshold values for a single variable from Purkait's method and the femoral head diameter raised the predictability to greater than 90% for both sexes.     

染色毛干mtDNA不同提取方法的研究

目的为染色毛发线粒体DNA选择最佳的提取方法。方法在5个染发个体中各取5根头发,采用Chelex-100法、有机法、磁珠法、H2O2结合Chelex-100法及Chelex-100结合M icrocon100法等5种不同的提取方法提取染色毛发m tDNA,利用2%琼脂糖凝胶电泳检测扩增产物。结果Chelex-100结合M icrocon100方法提取染色毛发扩增m tDNA效果较好,其余方法无扩增产物。毛发的不同部位对扩增结果无影响。结论染色毛发采用恰当的提取方法可以提取到m tDNA模板,为法医日常检案提供帮助。     

Detection of semen and blood stains using polilight as a light source.

Photoluminescence spectra of dry untreated semen have been measured and a suggested method for rapid detection of untreated semen stains is derived from these measurements. The method is presented in the form of a flow chart to cover most crime scene situations. The absorption spectrum of dry untreated blood has also been measured and a suggested method for enhancement and photography of blood stains is derived from this measurement. The method is presented in the form of a flow chart. Both methods are based on the use of a high intensity light source such as the Polilight.     

A Procedure for Calculating the Vertical Space Height of the Sacrum When Determining Skeletal Height for Use in the Anatomical Method of Adult Stature Estimation

Estimating stature from skeletonized remains is one of the essential parameters in the development of a biological profile. A new procedure for determining skeletal height (SKH) incorporating the vertical space height (VSH) from the anterior margin of the sacral promontory to the superior margins of the acetabulae for use in the anatomical method of stature estimation is introduced. Regression equations for stature estimation were generated from measurements of 38 American males of European ancestry from the William M. Bass Donated Skeletal Collection. The modification to the procedure results in a SKH that is highly correlated with stature (r = 0.925–0.948). Stature estimates have low standard errors of the estimate ranging from 21.79 to 25.95 mm, biases from to 0.50 to 0.94 mm, and accuracy rates from 17.71 mm to 19.45 mm. The procedure for determining the VSH, which replaces “S1 height” in traditional anatomical method models, is a key improvement to the method.     

A test of the effectiveness of the revised maxillary suture obliteration method in estimating adult age at death

The effectiveness of the original maxillary suture method for estimating age at death, introduced in 1987 by Mann and colleagues, has been tested, but their revised maxillary suture method (1991) has not been subject to similar scrutiny. The purpose of this study is to test the accuracy of the revised maxillary suture method in estimating age at death on a genetically diverse skeletal sample of 155 maxillae (96 males, 59 females, aged 26 to 100 years) of known age at death from the Department of Anatomy and Cell Biology, University of Cape Town, South Africa. Results from a prior study of the original maxillary suture method will be compared. With age category correctly estimated for 83% of this sample, the results of this study indicate that the revised method is more effective in estimating age at death than the original method. The revised method appears to perform best for older individuals and tends to underestimate age for individuals of all age groups. The results suggest that the revised method is useful as a method for age estimation when it is used conjunction with other estimators.     

顶空气相色谱法测定生物组织中的一氧化碳

本文主要研究用顼空气相色谱法测定生物检材中的一氧化碳。分析一个样品只需三分钟即可完成。本法不但适用于血样检材,而且适用于生物组织,甚至腐败生物检材,对于血液样品的最小检测量为50μl,变异系数为0.023。本文研究的方法已成功地应用于法庭科学一氧化碳中毒案件的检验。并描述了贮存的方法。     

Simulation-based reconstruction of traffic incidents from moving vehicle mono-camera

Video recordings from digital cameras implemented in road vehicles present a valuable source of data concerning various dangerous traffic situations, i.e., road accidents or near-miss incidents. This data is readily available and numerous methods for forensic reconstruction of traffic situations from vehicle video were presented in the past. New alternative method for reconstruction of traffic situations from vehicle video is presented in this article. The method is based on the fusion of kinetic vehicle trajectory simulation within 3D laser scanner point cloud, projective geometry, and processing of video footage from moving vehicle camera. The method offers accurate reconstruction of general vehicle motion within relevant time domain whereby in-depth technical information about traffic incident can be quantitatively extracted from video footage. The result is physics-based 3D projection of simulated vehicle motion on the motion of real vehicle recorded by moving monocular camera. The method was validated within performed experimental test runs with respect to vehicle speed, distance travelled, acceleration/deceleration and directional quantities (yaw rate, yaw angle). The method was further applied in the reconstruction of real-world traffic events.     

Development of a one-tube extraction and amplification method for DNA analysis of sperm and epithelial cells recovered from forensic samples by laser microdissection

Laser microdissection can be used in forensic casework to isolate specific cell types from mixtures of biological samples. Extraction of DNA from selected cells is still required prior to STR amplification. Because of the relatively pristine nature of the recovered cells, laser microdissection is more sensitive than more traditional methods of DNA analysis, theoretically resulting in DNA profiles from less cellular material. A one-tube extraction and amplification method minimises loss of DNA through liquid transfers and reduces the potential for contamination events occurring. In this paper, the development of a one-tube method for the effective extraction of DNA from laser microdissected sperm and epithelial cells is described. The performance of the in-house method was compared to that of a commercial DNA extraction kit for extraction of DNA from sperm and the downstream compatibility with STR amplification was determined for both sperm and epithelial samples. Full Identifiler™ profiles after 28 amplification cycles were obtained from as few as 15 epithelial cells and 30 sperm.     

运用酚-氯仿法结合磁珠法提取蝇蛆体内人类DNA

目的建立运用酚-氯仿法结合磁珠法从蝇蛆嗉囊内提取人类DNA的方法,从而提高STR分型检验的灵敏度。方法采用酚-氯仿法对蝇蛆嗉囊内容物中的人类DNA进行提取,提取产物经磁珠法纯化浓缩后用QuantifilerTM人类DNA定量试剂盒在7500型实时荧光定量PCR仪上进行PCR定量,再用AmpF■STR IndentifilerTM试剂盒在3130XL-Avant遗传分析仪上对这些DNA样本进行STR分型。结果本研究建立的方法可增加模板DNA浓度约为单独使用酚-氯仿法的2倍。用此方法提取到的DNA浓度[（0.218±0.041）ng/μL]可获得全部16个STR分型结果。结论酚-氯仿法结合磁珠法可以有效地提高提取到的人类DNA样本STR分型检验的灵敏度,对于从事法医昆虫学方面研究的工作者有较好的实用价值。     

我国犯罪学研究方法与方法研究

每个学科都有自己的研究方法,科学的研究方法是任何学科赖以建立和发展的工具,犯罪学作为一门社会科学,它也有自己的研究方法,而且犯罪学的研究方法呈现出多样化的特点。目前我国犯罪学研究中存在的问题是实证研究缺乏,定性与定量分析分离,研究范式单一陈旧,应整合研究方法,做到思辨与实证相结合,定性与定量相结合,寻求多学科理论支持,重塑犯罪学研究范式。     

A method for collection of gunshot residues from skin and other surfaces

A method of collecting gunshot residues from the skin of persons who have been injured by firearms has been developed. The method uses a commercially available, adhesive, transparent plastic film. This method is also useful for collecting gunshot residues from other objects, such as leather. The shooting distance is later estimated by ocular, microscopic or IR examination in combination with various chemographic tests.     

Trizol法大鼠心肌总RNA提取方法探讨

目的 探讨大鼠心肌总RNA的提取方法,为今后法医学研究和实践工作提供参考.方法 用Trizol法,严格注意无RNA酶操作,通过裂解组织,分离、沉淀RNA而提取大鼠心肌总RNA,并用分光光度计、凝胶电泳及RT-PCR检测结果.结果 Trizol法能获得较高纯度和产量的完整总RNA.结论 Trizol法是提取总RNA可靠有效的方法,可望在法医学领域有较广的应用.     

Modeling Bone Surface Morphology: A Fully Quantitative Method for Age‐at‐Death Estimation Using the Pubic Symphysis

The pubic symphysis is widely used in age estimation for the adult skeleton. Standard practice requires the visual comparison of surface morphology against criteria representing predefined phases and the estimation of case‐specific age from an age range associated with the chosen phase. Known problems of method and observer error necessitate alternative tools to quantify age‐related change in pubic morphology. This paper presents an objective, fully quantitative method for estimating age‐at‐death from the skeleton, which exploits a variance‐based score of surface complexity computed from vertices obtained from a scanner sampling the pubic symphysis. For laser scans from 41 modern American male skeletons, this method produces results that are significantly associated with known age‐at‐death (RMSE = 17.15 years). Chronological age is predicted, therefore, equally well, if not, better, with this robust, objective, and fully quantitative method than with prevailing phase‐aging systems. This method contributes to forensic casework by responding to medico‐legal expectations for evidence standards.     

显微操作法提取混合斑中精子细胞方法的探讨

目的尝试建立一种提取混合斑中精子细胞的检测方法。方法在人为控制条件下,制备精液—阴道液混合斑,分别使用显微操作法与差异裂解法分离精子细胞,提取DNA,进行STR基因型检测。结果采用显微操作法检测成功率11/12,差异裂解法成功率1/12,两者有显著性差异。结论显微操作法可有效获取精子细胞,排除女性物质和其它杂质的干扰,STR分型成功率优于差异裂解法。     

3种甲醛固定组织DNA提取方法的比较

目的对不同方法提取甲醛固定组织中DNA的效果进行比较,寻找一种操作简便、经济实用、质量较高的DNA提取方法。方法取甲醛固定的心肌组织14份,分别以改良酚-氯仿法,改良Trizol法,试剂盒法提取DNA,进行紫外分光光度计测定OD260/OD280值后,经PCR扩增,琼脂糖凝胶电泳分析确定提取的DNA质量。结果改良酚-氯仿法,改良Trizol法,试剂盒法OD260/OD280比值分别为1.841 5±0.380 4、1.370 5±0.336 7、0.831 6±0.175 0。两两比较均有显著性差异(P<0.05)。3种不同方法提取DNA含量分别为0.943 8±0.530 1、0.707 5±0.423 6、0.342 8±0.182 5。PCR扩增后琼脂糖凝胶电泳显示以改良酚-氯仿法所提DNA的谱带清晰度好于其它两种方法。结论改良酚-氯仿法简便有效,所用试剂价格低廉,是一种经济实用的甲醛固定组织DNA提取方法。     

血中十六种挥发性碳氢化合物的固相微萃取

为认定火灾现场烧死尸体 ,用固相微萃取技术从血中快速提取十六种碳氢化合物 (直链烃从八碳到十三碳 ,芳香烃从二甲苯异构体到三甲基苯 )。在室温条件下直接用 10 0 μm 聚二甲基硅氧烷萃取头以顶空方式萃取浓缩2 0min。气相色谱仪 ,氢火焰检测器测定 ,外标法定量。结果显示 :血中检测浓度可达 0 1μg/ml。固相微萃取是筛选血中碳氢化合物一种灵敏而准确的方法。     

陈旧性骨骼DNA提取技术的研究

对陈旧性骨骼建立一个高回收率并能除去 PCR 反应抑制物的提取 DNA 的方法。采用 CTAB 法提取 DNA。结果显示,该方法不但能有效去除 PCR 抑制物,而且对水泡、火烧、土埋以及10年左右的骨骼所提取的 DNA 均能成功地进行荧光标记 STR 多基因座扩增检验。实验表明,该方法稳定,重复性好,适合陈旧骨骼标本的 DNA 提取。     

DNA identification of sperm cells collected and sorted by flow cytometry

In cases of rape, obtaining enough biologic material for DNA identification of the attacker is often difficult because the methods for distinguishing and separating sperm cells from vaginal cells are not sufficiently efficacious. This article describes a new, innovative method for spermatic DNA extraction from the vaginal washing fluid by means of flow cytometry. The high specificity and sensitivity of the flow-cytometric sorting method provides enough sperm cells for DNA typing. The ease of execution of this method, involving vaginal washing with physiologic solution and flow-cytometric reading of the fresh sample, substantially increases its cost-benefit ratio.     

液上空间SPME/GC法测定生物样品中的甲醇

研究了血液及胃内容物中甲醇的液上空间SPME法.该方法快速、方便.     

Determination of gamma-hydroxybutyrate in water and human urine by solid phase microextraction-gas chromatography/quadrupole ion trap spectrometry

A simple method of detection was developed for gamma-hydroxybutyrate (GHB). The method involves the derivatization of GHB using a hexyl-chloroformate procedure in aqueous media (such as water or urine), extraction of the derivatization product directly from the sample using solid-phase microextraction, and subsequent separation and detection with gas chromatography quadrupole ion trap mass spectrometry. The deuterated form of GHB (GHB-D6) is used as an internal standard for quantitation. The method was linear for GHB-spiked pure water samples from 2 to 150 microg/mL GHB with a detection limit of 0.2 microg/mL. Spiked urine samples showed linearity from 5 to 500 microg/mL GHB with a detection limit of 2 microg/mL. The SPME-GC/MS method is applied to actual case samples, and the results are compared to those values obtained using a conventional GC/MS method. Sensitivity and linearity are comparable to those seen using traditional methods of separation, yet the SPME method is superior due to the simplicity, speed of analysis, reduction in solvent waste, and ability to differentiate between GHB and gamma-butyrolactone (GBL).