应用SEM/EDX和ICP-AES检测元素成份判定致伤工具

目的应用扫描电镜/能谱联合分析仪(Scanning electron microscopy & Energy dispersive X-ray apparatus SEM/EDX)和电感耦合原子发射等离子光谱(inductively coupled plasma-atom emission spectrometer ICP-AES)对金属致伤工具本身及所致创口残留物元素成分分析,探讨两者在推断认定此类工具的应用条件及价值.方法镀层和普通铁质工具在乳猪皮肤各致创5例,SEM/EDX对创口内遗留金属颗粒元素检测;用标准样品检测实验方法的精确度;普通铁质工具于刀背、刀刃处各取5个样本,ICP-AES测定元素成分与含量.结果镀锌工具所致创口中存在单一含有锌的金属颗粒,镀黄铜工具则同时含有锌和铜,未发现其它元素;不锈钢或普通铁质菜刀创口中,发现同时含有铁、铬、硅或铁、锰、硅的颗粒;除5号菜刀外同一把铁质菜刀在刀刃、刀背处元素含量无明显差别;ICP-AES分析表明不锈钢菜刀之间在铬、锰、硅、铜、钼和5号刀背部以及其他铁质菜刀在锰、硅元素含量差别具有显著意义,5号刀刃部锰、硅、钼、钛、磷、硫、镍元素RSD明显升高.结论SEM/EDX可以通过创口的检测对金属致伤工具进行种类的推断认定,ICP-AES则可在同种类致伤工具中进行相对同一的判定有应用价值.     

骨砍创金属颗粒的检测

目的 应用扫描电镜/X射线能谱仪(SEM/EDX)对菜刀砍击骨质后遗留在创面上的金属微粒进行检测.方法 3种不同材质菜刀各取5把,对猪大腿骨进行砍击,使用SEM/EDX对骨创面上附着的金属颗粒元素以及菜刀自身所含元素进行定性及定量检验,并对结果进行比对分析.结果 菜刀样本同型号之间元素重量百分比相比较,结果无统计学差异(P＞0.05);创面附着金属颗粒与菜刀自身所含元素种类特征相同;其所占重量的百分比一致(P＞0.05);结论 骨骼创面遗留金属颗粒的元素种类及其百分比含量,可以作为区分菜刀类致伤工具的重要依据.     

铁铬合金菜刀遗留金属颗粒的成分评价方法

目的检测铁铬合金菜刀遗留的金属颗粒成分,并建立可行的评价指标及方法。方法使用滤纸擦蹭菜刀制作金属遗留微小颗粒样本,应用扫描电镜-X射线能谱仪(scanning electron microscopy and energy dispersive X-ray spectrometer,SEM-EDX)的GSR颗粒分析功能检测遗留金属颗粒成分,计算遗留金属颗粒中铁、铬相对含量比。结果铁铬合金菜刀遗留金属颗粒内所含铁、铬相对含量比,在大部分菜刀间差异有统计学意义(P0.05)。结论使用GSR颗粒分析功能量化检测铁铬合金菜刀遗留金属颗粒内铁、铬相对含量比,为此类致伤工具的认定建立可行的评价方法。     

采用SEM/EDX方法推断铜锌镀层钢管的种类

目的采用扫描电镜/X射线能谱仪(SEM/EDX)法推断铜锌镀层钢管的种类,评价其在推断工具种类认定中的意义。方法用3根铜锌镀层钢管打击滤纸和猪皮后,分别提取残留的金属颗粒各5组,使用扫描电镜/X射线能谱仪颗粒分析方法进行检测,用SPSS 13.0软件对所得铜锌颗粒成分数据进行统计学分析。结果通过Cu和Zn元素相对含量的均数±标准差(x—±s),评估铜锌镀层钢管打击滤纸和猪皮后所残留的铜锌元素金属颗粒的稳定性。不同种类钢管残留金属颗粒成分(P0.05)有显著差异,同一把钢管打击猪皮和滤纸残留金属颗粒(P0.05)无差异。结论 SEM/EDX颗粒分析方法可以对铜锌镀层钢管进行种类认定。     

SEM/EDAX检测内脏异物元素成分诊断溺死

为探讨溺死诊断的依据和推断入水地点，用扫描电镜／X－射线谱仪（SEM／EDAX）检测19例溺死尸体及28只溺死兔的肺、肾、心、肝等组织异物颗粒及其元素成分和含量，并以陆地上死亡尸体14具及8只陆地上勒死兔（2只勒死后入水浸泡6天）作实验对照。结果发现，19例溺死尸体及28只溺死兔的肺边缘区呼吸性细支气管、肺泡管、肺泡囊及肺泡内均可见高能谱值的异物颗粒，其大小自数微米至数十微米不等，多为无定形异物颗粒或细小异物颗粒集落。其中元素成分为硅、铝、钙、铁、铬、钛、钼、铅、锡、铜、溴等，与入水地点溺液中所含元素成分相同；肾、心、肝组织异物颗粒检出率分别为77％、53％及47％，数量较少，颗粒较小，大小自1微米以下至十数微米。非溺死尸体及实验兔的肺、肾、心、肝组织未检出或偶尔检出异物颗粒，其元素成分多为铁、钙或硅等，可能是病理及生理性异物颗粒，如含铁血黄素、钙化灶等。用SEM／EDAX检测水中尸体组织中异物颗粒及其元素成分和含量，可以诊断溺死，推断入水区域，为明确案件性质和确定侦察范围提供科学依据。     

致伤工具微量残留物提取和检验研究

目的研究猪皮损伤创口内微量物证提取检验方法,探索致伤工具残留物成分认定方法。方法用锤子打击猪皮,并用滤纸、棉花棒提取损伤创口的微量物质,应用扫描电镜X射线能谱技术检验,确定致伤工具成分。结果猪皮残留微小颗粒可以定量地与锤子成分进行比对检验,扫描电镜X射线能谱技术可对微小颗粒成分分析。结论该方法可以作为致伤工具成分认定的参考,对致伤工具推断具有现实意义。     

钢锤打击后皮肤遗留金属颗粒成分检测

目的应用扫描电镜-X射线能谱仪(scanning electron microscope and energy dispersive X-ray spec-trometer,SEM-EDX)对钢锤打击猪皮和滤纸遗留金属颗粒进行元素成分分析,为钝器致伤工具推断研究建立方法。方法使用两把不同的钢锤分别打击猪皮和滤纸,应用SEM-EDX检测遗留金属颗粒,利用SPSS13.0对检测结果进行统计分析。结果同一把钢锤多次打击遗留颗粒成分特征稳定,打击猪皮和滤纸遗留颗粒成分差异无统计学意义,两把成分不同的钢锤遗留颗粒成分差异有统计学意义。结论 SEM-EDX可以对钢锤遗留的颗粒进行成分检验,为法医学致伤物推断提供新的途径。     

根据创口射击残留物推断“5.4”式手枪射击距离的研究

目的利用环境控制扫描电镜/能谱仪（SEM/EDX）研究枪弹创射入口周围射击残留物与射击距离的关系,探讨其能否用于射击距离的判断。方法采用＂＂5.4＂＂式手枪分别在5、10、15、20、30、40、50、60、70、80、90、120cm处射击乳猪皮肤,利用SEM/EDX观察创口周围GSR的分布和成分,并建立回归方程。结果射击距离和GSR颗粒数量之间总体表现为直线关系,并建立了相应的回归方程。当射击距离为10~90cm时,用该方程推断射击距离效果较好。结论检测创口周围GSR可望用于判断“5.4”式手枪的射击距离。     

两种铁铬合金电警棍遗留金属颗粒成分分析

目的检测两种电警棍铁铬合金电极遗留金属颗粒的成分,对同一电警棍电击前后遗留金属颗粒成分特征进行分析,对电警棍遗留金属颗粒成分的稳定性、差异性进行评价。方法使用电警棍分别多次摩擦滤纸和电击猪皮,使用碳导电胶带粘取遗留金属颗粒,应用SEM/EDS技术检测颗粒元素成分,并对数据进行统计学分析。结果两种电警棍电击前遗留铁铬合金颗粒及电击后遗留铁铬合金颗粒成分均稳定,存在差异;实验两种电警棍电击后遗留金属颗粒成分分布发生显著变化,除原成分铁铬颗粒外,实验猪皮表面均检出全新成分的铁铬合金颗粒,且两种电警棍电击后产生的全新铁铬颗粒成分稳定无显著差异。结论通过分析两种电警棍铁铬电极电击前后遗留多金属颗粒成分分布特征,可以实现对两种电警棍电极的识别,为人体电警棍损伤的识别与认定提供技术支持和理论依据。     

冲镐捅击腹部致胃破裂1例

冲镐类似两头尖的扁担，两尖端包有铁质尖角，尖角为块状钝角。用冲镐作致伤工具，尚未见报道，就作者所在地而言，也是很少见的．现就本例冲镐造成的特殊损伤，报告如下：1案例陶某，男．22岁。某日上午9时许，被他人用冲镐捅击腹部，伤后即感腹痛，伴频繁呕吐，呕吐物中带血，急送县人民医院治疗。12时30分入院，见面色苍白，四肢厥冷，体温37℃，脉搏90次／分，呼吸20次／分，血压9／5kPa呈失血性休克状态．满腹胀痛，左上腹为甚，腹穿抽出较多未凝固血液．急行腹部手术，术中见左上腹壁皮下的腹内、外斜肌等肌肉与腹膜洞状破裂，肌肉内…     

Identify the injury implements by SEM/EDX and ICP-AES

The forensic investigator is frequently confronted with the discrimination and deduction of injury implements, which is one of the most important physical testimonies in courts. The usual method used in actual cases is from points of morphology. In the forensic discrimination of injury implements, such as metal implements, the analysis and comparison of elements are expected to provide excellent results, and simultaneous multi-elemental analysis is required to analyze various kinds of elements. This study was designed to establish discrimination and deduction of metal injury implements by scanning electron microscope/energy disperse X-ray microanalyzer (SEM/EDX) and inductively coupled plasma atomic emission spectrometry (ICP-AES). Examined metal particles in five wounds made on the skin of domestic pigs, respectively, using Cu-Zn or Cr-Ni coated and carbon steel kitchen implements by EDX. For carbon steel kitchen implements, analyzed five samples from the back and blade separately in the contents and varieties of elements by ICP-AES. In the wounds by the coated implements, the special particles only containing Cu, Zn or Cr, Ni were found. In the wounds by carbon steel kitchen implements, the particles containing Fe, Cr, Si or Fe, Mn, Si were found. The differences of contents of elements between the back and blade was no significant except No. 5 for carbon steel kitchen implements, and the significant differences of elements exited in Cr, Mn, Si, Cu, Mo among the stainless kitchen knives, Mn, Si among the other kitchen implements and for the blade of No. 5 knife, relative standard deviations (R.S.D.s) were significantly different in Mn, Si, Mo, Ti, S, P, Ni. Using EDX to examine the particles in wounds can deduce the categories of metal injury implements, and we can still deduce the different implements in the same category by ICP-AES.     

The differential diagnosis and the identification importance of the track of the heel of stabbing-cutting weapons in skin wounds

Data on 123 cut-stab wounds and 52 knives were examined in the course of medicolegal expert evaluation. It was found that 30 knives possessed heels which could have two forms: symmetric and asymmetric. Heel traces were seen in 16 expert evaluations (34%) in 31 wounds (25.2%) and in some of them particular features of knife blade heel were represented. Differences between butt end and heel trace according to series of signs were noted.     

Morphologic, experimental-comparative investigation as an identification of the injuring instrument method

Aiming to identify the injuring tool characteristics and the tool itself morphologic, experimental-comparative investigations of the skin wound, rib and cartilage injuries taken during the autopsy are performed. During 1995-2004, 489 investigations were performed for this purpose. In 418 cases, knives were submitted for identification of the specific injuring tool (in total-835 knives). In 205 cases the investigation included not only skin wounds, but also the injured rib cartilages. Identification investigations were performed by investigating both the skin wounds morphologic characteristics and dynamic traces-trails in the rib cartilage tissue left by the micro relief of the knife blade edge. In the case of the investigated and experimental skin wounds characteristics coincidence the experimental and comparative dynamic traces investigation was performed when the traces were suitable for the tool identification purposes. In the case of the investigated and experimental skin wounds, dynamic traces coincidence, the totality of the coincided characteristics was considered individual. In those cases, the conclusion included the fact that the injury had been made by a particular knife. According to our data during 1995-2004 in 23 cases-15.9% (5.5% out of the total investigated cases), the knife identification was based on the skin wound characteristics and dynamic traces in the rib cartilage tissue. In our opinion, the dynamic traces in the rib cartilage tissue investigations supplement the identification field and are valuable in the tool identification. In 11 (2.6% out of the total investigated cases) cases knives were identified only by the skin wounds morphologic characteristics, the ribs being not injured or dynamic traces being not suitable for the tool identification.     

Immunocytochemical examination of biological traces on knife blades

In cases of penetrating stab wounds by different knives it is highly relevant to prove which knife caused which injury, especially if one of the injuries was lethal. This is possible by immunocytochemical examination of cellular material remaining on the injuring blade because some organs have organ-specific antigen determinants such as alpha-l-fetoprotein in the liver cells or cardiac troponin I in the heart muscle cells, to which antibodies can bind. Even when penetrations occur through several layers of clothing, enough cells from the injured organ remain on the blade of a knife to allow immunohistochemical examination. These cells can be collected by means of adhesive film or wiping the blade and can be stained immunocytochemically. The organ specificity of the examined proteins allows proof of their origin. The present study shows that immunocytochemical alpha-l-fetoprotein and cardiac troponin I staining of the cells remaining on a knife blade enables proof of whether the knife blade injured the heart or the liver, or both.     

Characteristics of Bone Injuries Resulting from Knife Wounds Incised with Different Forces

The aim of this research was to experimentally determine the characteristics of incised bone wounds, which are commonly found in defense injuries. A specially constructed pivoting arm device was used to inflict wounds with controlled forces and direction. Five knives were selected to inflict the wounds on porcine forelimbs. Eight incised wounds were made per knife per force. A larger knife and a greater force caused longer and wider bone wounds. Comparisons of individual knives at the two forces produced varying results in the bone wounds. A correlation was seen between the force and the length (r = 0.69), width (r = 0.63), and depth (r = 0.57) of bone wounds. Serrated‐edge and nonserrated knives can be distinguished from the appearance of the wound. The outcomes may be applicable in forensic investigations to ascertain the forces associated with incised wounds and identify the specific knife used.     

Striation patterns in serrated blade stabs to cartilage

Stab wounds were made in porcine cartilage with 13 serrated knives, amongst which 4 were drop-point and 9 straight-spine; 9 coarsely serrated, 3 finely serrated and 1 with mixed pattern serrations. The walls of the stab tracks were cast with dental impression material, and the casts photographed together with the knife blades for comparison. All 13 serrated blades produced an "irregularly regular" pattern of striations on cartilage in all stabbings. Unusual and distinctive blade serration patterns produced equally distinctive wound striation patterns. A reference collection of striation patterns and corresponding blades might prove useful for striation pattern analysis. Drop-point blades produced similar striations to straight-spine blades except that the striations were not parallel but rather fan-shaped, converging towards the wound exit. The fan-shaped striation pattern characteristic of drop-point blades is explained by the initial lateral movement of the blade through the cartilage imposed by the presence of the drop point shape. It appears that the greater the overall angle of the drop point, the shorter the blade length over which the drop point occurs, and the closer the first serration is to the knife tip, the more obvious is the fan-shaped pattern. We anticipate that micro-irregularities producing individualising characteristics in non-serrated drop point blades, provided they were located at the tip opposite the drop point, should also show a fan-shaped pattern indicative of a drop point blade. The examination of the walls of stab wounds to cartilage represents an under-utilised source of forensic information to assist in knife identification.     

Quantitative analysis of sharp-force trauma: an application of scanning electron microscopy in forensic anthropology.

Scanning electron microscopy (SEM) has occasionally been used by anthropologists and forensic scientists to look at morphological characteristics that certain implements leave on bone. However, few studies have addressed techniques or protocols for assessing quantitative differences between tool marks on bone made by different bladed implements. In this study, the statistical variation in cut mark width was examined between control and test samples on bone using a scalpel blade, paring knife, and kitchen utility knife. Statistically significant differences (p < .0005) were found between cut marks made by the same knife under control and test conditions for all three knife types used in the study. When the control sample and test samples were examined individually for differences in mean variation between knife types, significant differences were also found (p < .0005). While significant differences in cut mark width were found, caution should be used in trying to classify individual cut marks as being inflicted by a particular implement, due to the overlap in cut mark width that exists between different knife types. When combined, both quantitative and qualitative analyses of cut marks should prove to be more useful in trying to identify a suspect weapon. Furthermore, the application of SEM can be particularly useful for assessing many of these features.