鞋内底浸渍痕迹的检验

1 鞋内底浸渍痕迹的形成 鞋内底浸渍痕迹是指鞋在穿用过程中，由于脚的蹬踩与汗液的浸渍，形成在鞋内底或鞋垫上的印痕。这种印痕与赤足足底具有对应性，在足迹检验中具有较高的利用价值。根据运动力学和生理学的原理，每个人的生理特点和运动能力的差异，形成的运动特征也各不相同，在鞋内底及鞋垫上会形成深浅、虚实不一的赤足形象特征，这就给我们的检验提供了有利的条件。     

鞋内底浸渍痕迹在足迹鉴定中应用

鞋内底浸渍痕迹包括通常所说的鞋内底磨损面、鞋垫上的浸渍痕迹等,该痕迹的形成是由于人脚上汗孔排出的汗液在鞋内不易挥发,其中的盐分和其他有机质很容易在鞋内底、鞋垫或皮革及各种合成材料上形成脏污的痕迹,因而鞋一经穿用,脚掌在鞋内固定,穿用人脚的结构形态就通过脚表面的汗液介质在鞋内底或鞋垫上反映出来。这种痕迹在实际工作中同样有较高的利用价值,本文通过一例案件现场上足迹的检验,对鞋内底浸渍痕迹进行了初步探讨,供同行们参考。1案情简介2002年5月10日晚,潜江市某街居民徐某(男,83岁)被人杀死在家中,现场勘查在死者上衣上提取…     

刑事现场188份接触DNA检材法医学检验分析

目的分析188份接触DNA检材的提取、送检和检验结果,探讨接触DNA检出率及可能影响接触DNA检验的因素。方法收集本辖区2016年1月至2016年10月提取并送检的188份接触DNA检材,按照检材载体性质、提取方法、送检时间、检出率等进行分类,采用SPSS13.0软件对数据进行统计分析和χ2检验。结果188份接触DNA检材成功进行STR分型的有38份,检出率为20.21%;其中表面质软、粗糙的载体接触DNA检出率58.82%,高于其它载体接触DNA检出率组的差异具有统计学意义;直接原物提取的接触DNA检材检出率42.11%,高于脱落细胞粘取器提取、棉签拭子转移提取的检出率组的差异具有统计学意义;送检时间早的检材检出率高于送检时间晚的检材组且具有统计学意义。结论接触DNA检材的检出率受载体性质、提取方法、送检时间等因素影响,日常现场勘查时要注重发现检出率高的载体上的接触DNA选择适当的方法提取,并及时送检。     

215例枪支上接触DNA检材的检验分析

目的分析215例枪支上接触DNA提取、送检及检验结果,探讨枪支上接触DNA检出情况及可能影响检验结果的影响因素。方法收集自2013年以来受理的215例涉案枪支上接触DNA检材,按照提取部位、检出率、送检时间、检验方法进行分类并对数据进行统计分析。结果215例接触DNA成功检出35例,检出率为16.28%;枪支上不同部位接触检材的检出率无明显差异;硅膜法与改良硅珠法的检出率无明显差异;送检时间早的检材检出率高于送检时间晚的检材并具有统计学意义。结论枪支上接触DNA的检出率与提取部位、送检时间、检验方法等因素有关,日常类似检材应合理提取、及时送检并采取正确检验方法。     

QIAcube小型工作站在生物接触类检材提取中的应用研究

目的 探讨QIAcube工作站在生物接触类检材中的提取效果。方法 将90份以脱落细胞粘取膜、实物样本(纱线转移)或棉签擦拭物为载体的生物接触类检材,分别采用QIAcube工作站、EZ1工作站和手工硅珠法进行基因组DNA提取、定量并检测15个常染色体基因座的STR分型。结果 利用QIAcube工作站提取的生物接触类检材平均检出率达到44.4%,其中脱落细胞粘取膜组检出率为56.7%,实物纱线转移组检出率为46.7%,棉签擦拭物组检出率为30.0%。脱落细胞粘取膜组和实物样本(纱线转移)组均获得较好的STR分型结果,所得DNA浓度均优于棉签擦拭物组样本。QIAcube工作站组平均检出率为44.4%,手工硅珠法组平均检出率为43.2%,而EZ1工作站组平均检出率为26.9%,前两者平均检出率明显高于EZ1工作站组。QIAcube工作站组与硅珠法组所得DNA浓度无显著差异,但均明显高于EZ1工作站组。QIAcube工作站组与硅珠法组检测得到的STR分型RFU值及峰值均衡性均优于EZ1工作站组,尤其是大片段基因在前两组中均能够被完整检测到。结论 采用QIAcube工作站提取生物接触类检材检出率高,STR分型结果良好,可应用于法医物证实际案件检验。     

杯口边缘附着微量口唇脱落细胞的检验

目的　探讨对遗留在杯口边缘的微量口唇黏膜脱落细胞进行DNA分型的可行性及影响因素 ,为案件的侦查提供指导作用。方法　分类提取饮水后容器边缘口唇黏膜脱落细胞中的DNA ,应用荧光标记PCR STR分型技术进行DNA分析。根据每个样本DNA基因座的检出个数 ,分别计算出基因座检出率。结果　不同容器、不同饮料对口唇黏膜脱落细胞DNA检验的影响不同。结论　杯口遗留的口唇黏膜脱落细胞 ,可作为一种法庭生物检材进行DNA分析 ,在实际办案中占有一席之地     

3种方法联合运用提取人体脱落上皮细胞DNA

目的寻求提高法医物证检验中附有人体脱落细胞载体检材的DNA检出率的方法。方法根据案件检材的具体条件．选择3种提取方法即Chelex-100法、Chelex-100联合有机法和Chelex-100联合磁珠法。结果采用了分步提取DNA法,可充分、有效地提取微量DNA,提高了人体脱落上皮细胞有效DNA的检出率。结论根据第一步提取方法的检测结果,来调整下一步的提取策略,如是否加以纯化浓缩,可增加人体脱落上皮细胞有效DNA的检出率。     

激光显微捕获技术用于尿液脱落细胞DNA检测

目的采用激光显微捕获技术（LCM）捕获尿液脱落细胞,并进行STR分型。方法收集10份健康成人尿液样本,根据储存时间分组,其中新鲜尿液组（≤24h）分别采用Chelex-100及LCM联合DNA IQTM提取法提取DNA,储存尿液组（〉24h）再分为4℃组和室温组,分别在4～30d内不同时间点采用LCM联合DNA IQTM提取法提取DNA;各组提取的模板DNA进行扩增及SRT分型检验。结果新鲜尿液组采用LCM联合DNA IQTM提取法提取DNA,所有样本均可检出全部基因座（16个）,采用Chelex-100法则在部分基因座上出现等位基因丢失、非特异性扩增、峰值低等现象;4℃储存10d和室温储存4d以内的尿液经检验可明确判读12个以上基因座,4℃20～30d及室温7d,可检出7个以上基因座。结论 LCM技术可用于尿液检材的DNA分型检验,且检材应尽可能4℃保存并尽快检验。     

生物检材采集与保存套管的应用

目的探讨生物检材采集与保存套管在法医学中的应用价值。方法在不同温、湿度环境下，观察悬空放置在生物检材采集与保存套管、有孔与外界相通的套管及密闭管内的湿润棉签的干燥时间30次；分别用生物检材采集与保存套管和医用棉签采集纸袋保存口腔细胞、血液、皮肤脱落细胞样本各20例，磁珠法提取DNA并进行DNA定量；用生物检材采集与保存套管采集口腔脱落细胞和血样进行DNA直接扩增。结果在温度4～30℃、相对湿度21％～90％的环境下，湿润棉签在套管内的平均干燥时间为7．89h，有孔管内的为23．30h，密闭管内观察15天仍不干燥，出现霉斑。生物检材用套管采集保存比医用棉签采集纸袋保存方式获得的DNA量显著提高，平均高达0．968倍；用套管采集口腔细胞和血样进行直接扩增，操作简单方便，成功率高。结论生物检材采集与保存套管具有快速干燥、对检材无损耗和浓缩等优点，可提高检材DNA的提取效率，且适合直接扩增。     

微量生物物证提取套装在现场微量血痕DNA检验中的应用

目的探讨微量生物物证提取套装应用于提取现场微量血痕DNA的检验效果。方法将静脉血制成地面血痕。分别应用微量生物物证提取套装法和普通法提取血痕。分别于恒温摇床放置2、24、48、72、96h(每组50份)进行血痕DNA检验,对比各组检验结果。结果恒温摇床上分别放置24、48、72、96h后,微量生物物证提取套装法的DNA检出率(分别为100.00%、100.00%、100.00%、96.00%)均高于普通法(分别为62.00%、26.00%、10.00%、0),差异均具有统计学意义(P<0.05)。恒温摇床上放置2h,两种方法的DNA检出率差异无统计学意义(P>0.05)。结论微量生物物证提取套装可有效提升放置时间较久的现场微量血痕的检出率和检出时限。     

Determination of DNA yield rates in six different skeletal elements in ancient bones

Current sampling strategy for laboratories typing bones for human identification include samples obtained from femur, tooth and temporal bone. Latest studies suggest that the small bones of the hands and feet were very similar or even better in DNA yield. These bones can be easily sampled with a disposable scalpel and thus reduce potential DNA contamination. The aim of our study was to determine the suitability of metatarsals, metacarpals and phalanges for genetic identification. 48 bone samples from 8 different skeletons (six from 18^th century and two from 3rd century) were obtained from 5 archaeological sites in Slovenia. In each skeleton, 6 different skeletal elements were sampled (temporal bone, molar, femur, metacarpal bone, metatarsal bone and proximal phalanx of the hand), and strict precautions followed to prevent contamination. Half of gram of bone powder was decalcified using full demineralization extraction method. The DNA was purified in a Biorobot EZ1 (Qiagen), DNA content determined with the PowerQuant kit (Promega), and autosomal STR typing performed with the Investigator ESSplex Plus kit (Qiagen). Up to 8.75 ng DNA/g of powder was obtained from samples analyzed. The highest yields were detected in temporal bone and the lowest in femur. The success rate of STR typing was evaluated according to the number of successfully typed loci and a strong correlation between the success rate of STR typing and the amount of extracted DNA was confirmed. For all eight skeletons full consensus genetic profiles were determined from skeletal elements analyzed. Our findings suggest it would be suitable to include metatarsal and metacarpal bones in sampling strategy for human identification although further research is needed to substantiate the findings of this study.     

A preliminary study investigating the overlay method in forensic podiatry for comparison of insole footprints

The overlay method is used in forensic podiatry to compare the shape, position, and overall fit of features between questioned and reference footprint evidence. However, the scientific foundation underpinning its validity in the comparison of insole footprints is not fully understood because of a lack of published data defining its statistical operating parameters. A review of literature revealed its subjective nature with little scientific validation, limited only to face validity.The aim of this study investigated strength of agreement between three expert footprint examiners’ overlay comparisons of ten reference insole footprints using Cohen’s weighted kappa (K_w). Validity of method was explored using measures of sensitivity, specificity, false positive rate (FPR), false negative rate (FNR), receiver operating characteristic (ROC) curve and area under the ROC curve (AUC). Results showed two examiners demonstrated high inter-rater consistency between their overlay comparisons (K_w: 0.981; 95 %CI: 0.943 to 1.020 for Rater1 v Rater2) whilst one examiner did not (K_w: 0.340; 95 %CI: 0.148 to 0.532 for Rater1 v Rater3; K_w: 0.310; 95 %CI: 0.100 to 0.519 for Rater2 v Rater3). Validity was investigated using a conclusion scale in a verbal expressions table to indicate support or rejection of compatibility of footprints between one questioned insole and ten reference insoles. Data analysis indicated validity as follows: Sensitivity: 77.8 %, Specificity: 61.9 %, FPR: 38.1 % and FNR: 22.2 %. ROC analysis corroborated this finding. AUC was calculated at 0.762 or 76.2 % indicating an ‘acceptable’ measure of overall accuracy of the overlay method for insole footprint comparison. Findings provide novel data supporting previous suggestions that the overlay method should not be used in isolation to compare insole footprints. Data also offers insight into the scientific foundation of this method, whilst highlighting its limitations and providing some implications and recommendations for forensic podiatry practice.     

Physical match: insole and shoe

In this case report, the authors show an interesting case of a physical match between an insole and a suspect shoe that was connected to the crime scene by a blood drop. Several pairs of shoes were seized and inspected. On the insoles of the main suspect's shoes, two different types of prints were seen, one was clear and the other image was faint. A physical match examination was conducted and the authors could place the right insole inside the right shoe. The insole was apparently glued to the shoe by the sweat, heat and dirt inside the shoe, and not by the manufacturer. In this case, the critical questions were how conclusive can the complexity of the random contours be, and whether the physical match between the two objects could pass the "Daubert challenge."     

三个单位点DNA杂交联合应用的研究

本文从一些多态位点中筛选出在中国人群中，对于同一种限制酶HaeⅢ酶解都能检出良好多态性的三个单位点探针（PMLJ14、PYNH24、α－globin－3’HVR）。对这三个位点的等位基因频率进行了调查．用DNA指纹自动识别系统进行了数据处理，各位点的数据如下：PMLJ14、杂合度94％，等位基因频率分布0．002～0．051；PYNH24：杂合度89％，等位基因频率分布0．003～0．152；α－globin-3’HVR：杂合度78％，等位基因频率分布0．003～0．077。分析15个家系，未见到变异发生，符合孟德尔遗传规律。这三个位点个人识别中的累加机率是：1．7×10-5～2．1×10-14。     

鞋内底足迹显现效果的影响因素

目的探究鞋内底足迹的显出情况及可能影响显现效果的因素,寻找有效的鞋内底足迹显现方法。方法收集PU材质的皮鞋鞋垫、EVA材质的运动鞋鞋垫、解放牌胶鞋鞋垫共144只,用多波段光源法、茚二酮法、茚三酮法三种方法分别对穿用时间为一周、一个月、三个月、六个月的鞋内底足迹进行显现,按照显现方法、材质、穿用时间进行分类讨论并对数据进行统计和分析。结果采用多波段光源法、茚二酮法、茚三酮法分别成功显出15、14、19例,有效显出率分别为31.25%、29.17%、39.58%,PU材质、EVA材质、解放牌胶鞋三种材质分别成功显出15、23、10例,有效显出率分别为31.25%、47.92%、20.83%,穿用时间为一周、一个月、三个月、六个月的检材分别成功显出3、6、13、26例,有效显出率分别为8.33%、16.67%、36.11%、72.22%。多波段光源法、茚二酮法、茚三酮法对鞋内底足迹显出率的影响,其差异无明显统计学意义;EVA材质运动鞋鞋内底足迹显出率高于PU材质皮鞋鞋内底足迹显出率,高于解放牌胶鞋鞋内底足迹显出率,并且差异具有统计学意义;穿用时间长的检材显出率高于穿用时间短的检材并且差异具有统计学意义。结论鞋内底足迹的显现效果与鞋内底材质、穿用时间因素有关,多波段光源法、茚二酮法、茚三酮法均能对鞋内底足迹有效显出。     

Two-dimensional metric comparisons between dynamic bare footprints and insole foot impressions-forensic implications

Footwear may be found at crime scenes as physical evidence. Such footwear often has impression features of the wearer’s foot on the insole of the shoe. Scientific research and literature have established that footprints are distinct. This study compares two-dimensional measurements on bare footprints to foot impressions on insoles to determine if significant differences or similarities exist. Dynamic footprints were collected from 51 donors using the Identicator® Inkless Shoe Print Model LE 25P system. Seven foot length and width measurements were taken based on the Reel linear measurement method. Footprint measurements between bare footprints and foot impressions on the insoles were compared. Only two differences (p > 0.05) were observed between the various bare footprint and insole foot impression measurements on the right and left side for most of the measurements, CALC (p < 0.001) and A1 (p = 0.04). Bare footprint and insole A5 measurements on the left side were also significantly different (p = 0.015). The results of the study have implications in the forensic analysis of foot impression evidence on insoles in footwear in assisting with identifying the wearer of said footwear. Situations may arise in the forensic context when comparing the foot impression on the insole of footwear to a suspect’s bare footprint or a footprint from post-mortem remains. This study contributes to the scant literature available on the topic and to understanding the similarities and differences observed in the various linear measurements that may be utilized in the comparison process of footprint impressions on shoe insoles to bare footprints.     

A new approach to upper cervical injuries

Severe injuries to the upper cervical region can be the cause of death. Standard autopsy techniques are inadequate for examination of this area. Therefore a technique has been developed that gives excellent visualization and allows removal of the brain and spinal cord in one piece. With the body prone a midline incision is made from the top of the head to the sacrum. The skull is sawed in a circle from one side of the foramen magnum around the top of the skull to the other side of the foramen magnum. The lamina of the neural arches of the vertebral column are sawed. With the removal of the piece of skull and the posterior portions of the neural arches, the posterior half of the cerebral cortex, cerebellum, and entire spinal cord are exposed. The entire brain and spinal cord can be removed as a unit. Cases are selected by history, X-ray examination, or floppy head. Four cases in which this approach has been helpful are briefly mentioned.     

辽宁汉族人血清类粘蛋白(ORM)型的分布及其在血痕精液(斑)及脑脊液中的检出

本文作者采用PAGIEF结合免疫固定法,调查了辽宁汉族群体(431人)ORM的分布,检出了ORM1型和ORM2型各8种表现型;对不同条件下的血痕标本进行检测,成功地检出了37℃保存2年血痕的ORM1型;首次由脑脊髓液中检出了ORM1型。ORM型的总鉴别机率为0.7043,是进行个人识别和亲子鉴定的良好遗传标记。     

Investigation into "normal" background DNA on adult necks: implications for DNA profiling of manual strangulation victims

Others have investigated the role that DNA profiling could play as a method for identifying the perpetrator of manual strangulation. These studies have demonstrated that it is possible to collect offender DNA from the skin surface of a victim following physical contact. It is not known whether nonself biological material is normally present on the skin surface due to adventitious transfer occurring during innocent everyday interactions. To test the hypothesis that detectable amounts of nonself DNA are normally present on the skin surface of healthy adult individuals due to the adventitious transfer of DNA occurring during normal day-to-day social interactions, we designed an experiment in three phases. Phase 1 was used to deduce which DNA collection, extraction, and amplification methods were suited to investigating this question. During phase 2, the neck surface of 24 healthy adult volunteers was swabbed. DNA was extracted using the QIAamp DNA mini kit and amplified using the SGM Plus PCR amplification kit, using 28 PCR cycles. The work carried out during phase 3 involved a simulated assault to investigate primary and secondary transfer of DNA during physical contact. It was found that 23% of neck areas swabbed during phase 2 of this investigation showed nondonor alleles in the resulting DNA profile, with 5% of areas showing six or more nondonor alleles. The results of phase 3 showed that primary, secondary, and zero transfer of victim and/or offender DNA could be observed after physical contact and that alleles from an unknown source could still be detected in this more controlled experiment. The data presented in this paper demonstrate that DNA profiles generated after swabbing the skin surface of healthy adults can include components of an unknown source, present due to adventitious transfer. These components, if present in large quantities, have the potential to interfere with DNA profile interpretation of swabs taken for the investigation of physical assault by DNA profiling.     

牙髓细胞DNA含量与死后经过时间的相关性

目的探讨死后不同环境温度下离体牙的牙髓细胞平均DNA含量变化与死后时间(PM I)的相关性。方法采用细胞图像分析系统(PIPS-2020),测定离体即刻至15d牙齿在低温环境(10~15℃)和高温(30~35℃)环境下牙髓细胞DNA含量变化值,并对其数据进行统计学分析。结果在不同的环境温度下,牙髓细胞DNA降解的速度有所不同,温度的升高有加速牙髓细胞DNA降解的趋势,且DNA降解存在一个平台期。低温组牙髓细胞平均DNA含量与PM I之间的相关系数r=0.953,相关指数R2=0.917;高温组的相关系数r=0.991,相关指数R2=0.971。结论牙髓细胞平均DNA含量与PM I之间具有高度相关性,测定牙髓细胞的DNA变化情况对推断3d(高温环境)或6d(低温环境)后的PM I有参考价值。