利用金属疲劳断口痕迹查明误报盗割案件1例

金属材料在交变循环应力或应变的循环加载下，在某些点会产生局部的永久性损伤，并在一定循环次数后形成裂纹或使裂纹进一步扩展直到完全断裂的现象叫做金属疲劳。疲劳断裂具有在时问上的突发性，在位置上的局部性及对环境和缺陷的敏感性等特点，故疲劳破坏常不易被及时发现且易造成事故。疲劳断口保留了整个断裂过程的很多信息，具有明显区别于其他任何性质断裂的断口形貌特征，研究和应用金属疲劳断口的痕迹特征可以帮助我们甄别案件的性质。笔者曾遇到一起误报盗割铁路器材案件，后运用金属疲劳的相关理论澄清了案件性质，报道分析如下。     

普通正三轮摩托车转向前叉断裂原因分析

通过对一辆导致了事故的普通正三轮摩托车转向前叉左侧减震器筒与其底座焊接部位的断裂原因进行分析。经过对断口宏观形貌、微观形貌的观察,以及对断裂部位材质、金相组织的检验分析,判断转向前叉的断裂为沿焊接结合面发生的沿晶韧窝断裂,是因焊接工艺不合理引起的。     

事故现场金属断口的宏观分析

事故现场金属断口的宏观分析王建军在事故现场中，经常会遇到由于金属机械设备零部件断裂而引发的恶性伤亡事故。因此，掌握一定的观察和分析方法对判断失效原因查清事故责任具有很大帮助。断口分析包括宏观分析和微观分析两种方式。由于微观分析需要有专门仪器如金相显微...     

酒驾肇事的定罪量刑及其刑法完善

回顾过去一年里发生的几起重大交通事件,无不都是血淋淋的教训,对几起具体案例进行分析,不难发现,看似相同的交通事故,判决却截然不同,有的定刑为交通肇事罪,有的则是以危险方法危害公共安全罪,这同时也引起了众多民众不同的呼声和疑问。借此,笔者认为急需通过增加过渡罪名对酒驾肇事进行立法完善。     

法医断口学理论和实践——骨折表面特征及其与裂纹扩展关系的分析

断口学理论和技术可以运用于刑事犯罪现场勘查和法医学鉴定，由此形成了法医断口学，利用骨折断面/断口特征分析其形成机制。骨折断口的重要特征包括骨镜和骨褶皱，可以观察到外力引起的经向裂纹、环状裂纹和锥形裂纹及裂纹分支，同时还可以观察到弓形线、止裂嵴、尾迹毛刺、悬臂式卷曲等，据此判断骨折的起点和终点，由此推断骨折的发生机制、致伤原因、致伤物等重要的法医学信息。     

处理机动车交易纠纷案应注意的几个问题

最近,我们对市区县法院1984年至1987年审结的32件因机动车交易而引起的纠纷案件进行了调查分析,发现存在的问题主要是:一、错误的确认当事人诉讼地位的有12件,占该类案件总数的37.5%。如有的将第三人确认为被告;有的遗漏了诉讼第三人;有的企业法人是被告,却将法定代表人列为     

弥漫性轴索损伤的扫描电镜观察

弥漫性轴索损伤是一种具有独特的临床、病理学特征的脑损伤，是重型脑损伤的主要死因之一，作者对６例脑外伤ＳＥＭ研究发现：大脑皮质挫伤远区可见神经细胞树实折断，轴索排列紊乱、断裂、粗细不等，有的断端球形扩大（ｒｅｔｒａｃｔｂａｌｌ）。髓鞘变性、表面粗糙、呈筛孔状，有的坏死脱落至轴索裸露，有的可见星形细胞附着在毛细血管壁的足板有断裂，毛细血管淤血、弯曲、破裂出血、出血区可见纤维蛋白网络红细胞。ＳＥＭ下上述病变观察清楚，立体感强，不失为一种先进的研究手段，脑外伤ＤＡＩ的研究中尚未见报告。     

调和汽油的GC-MS检验与区分

调和汽油在涉火案件中出现的频率逐渐增加,其特殊的组成可能对成分研判造成干扰。为准确识别汽油组分,区分不同来源的调和汽油,本文依托气相色谱–质谱（GC-MS）检验了部分典型调和油品,分析了相关样品的谱图特征并进行归类。结果表明,案件中常见的调和油品按照谱图主要特点可划分为添加剂异常、异构烷烃异常、直链烷烃异常和多组分异常四类。其中前两类对汽油及其残留物鉴定基本不构成干扰,而直链烷烃异常类油品可能引起误判,多组分异常类油品则不宜轻易下汽油结论。该研究结果对特殊调和汽油及其残留物的检验鉴定有一定的指导意义,对于涉火案件中汽油的比对分析和来源推断具有实战应用价值。     

涉农职务犯罪新趋势的分析

随着我国城市化进程的不断推进,国家加大了对农村的投资,有些不法分子,钻法律空子、找政策漏洞,想方设法,贪污、截留农资款,有的在农村基础建设中为谋取私利,收受贿赂,有的公开索要,致使工程质量下降,有的还造成严重的工程事故,这种坑害农民、农村的行为,在社会上引起了农民的极大不满。     

防患于未然——家庭纠纷的预防

山东省文登县司法局在排查民间婚姻、赡养、家务、继承、债务纠纷中发现百分之六十四是因分家遗留问题引起。主要原因是,有的口头协议分了家,分家后情况变化而发生争执,但无据可查;也有的当时分得不清,事后发生纠葛;还有的子女在对老人的赡养、债务等问题上引起新的矛盾。     

A traffic accident caused by fatigue failure of axle

An investigation of a traffic accident involving a tractor-trailer and a passenger car that were traveling at high speed is presented. The cause was the fracture of a trailer axle. The investigation showed that the fracture was because of the fatigue failure. In addition, cracks were found in the remaining three trailer wheels. Hardness measurements showed that, because of inadequate heat treatment of the metal, they were prone to failure.     

Heat-induced dimensional changes in bone and their consequences for forensic anthropology

An understanding of heat-induced transformation of hard tissue is vital before a full interpretation of burned human remains can be successfully achieved. Samples of modem sheep (n = 60) were analyzed resulting in 5440 data points. An experimental approach was undertaken that explored the bi-variable impact of heating temperature and duration of burning. Subsequent heat-induced bone changes included the progression of color from natural through to blue-white, the significant loss of weight, the reduction in mechanical strength, the development of distinct fracture patterns, alterations in the microscopic porosity, substantial alterations in crystalline structure and reduction and expansion in size. Collation and integration of this information demanded a revision of the four stages of heat-induced degradation of bone previously presented by Mayne Correia (1) and Thompson (2). The results demonstrate that heat-induced shrinkage is also accompanied by expansion and that both can be statistically significant. This suggests that anthropological techniques applied to burned bone will likely be detrimentally affected and accuracy will be reduced.     

What can a baby's skull withstand? Testing the skull's resistance on an anatomical preparation

A fall scenario is often given to explain the reason for a head injury to an infant. Mostly the examining doctor or forensic expert has to rely on his own experience and to appraise the situation to be consistent or not with his finds. An experiment carried out on an anatomical preparation showed that the skull of a newborn baby was able to repeatedly resist forces of up to 1000 N before breaking in. Even then the fracture lines followed the bony spikes (spiculae) from the ossification centers of the skull bones. If fractures are running across these spiculae there is reason to believe that high local force has been used, and a blow against a sharp edge must be considered.     

Role of preoperative 3-dimensional computed tomography reconstruction in depressed skull fractures treated with craniectomy: a case report of forensic interest

Patients affected by cranial trauma with depressed skull fractures and increased intracranial pressure generally undergo neurosurgical intervention. Because craniotomy and craniectomy remove skull fragments and generate new fracture lines, they complicate forensic examination and sometimes prevent a clear identification of skull fracture etiology. A 3-dimensional reconstruction based on preoperative computed tomography (CT) scans, giving a picture of the injuries before surgical intervention, can help the forensic examiner in identifying skull fracture origin and the means of production.We report the case of a 41-year-old-man presenting at the emergency department with a depressed skull fracture at the vertex and bilateral subdural hemorrhage. The patient underwent 2 neurosurgical interventions (craniotomy and craniectomy) but died after 40 days of hospitalization in an intensive care unit. At autopsy, the absence of various bone fragments did not allow us to establish if the skull had been stricken by a blunt object or had hit the ground with high kinetic energy. To analyze bone injuries before craniectomy, a 3-dimensional CT reconstruction based on preoperative scans was performed. A comparative analysis between autoptic and radiological data allowed us to differentiate surgical from traumatic injuries. Moreover, based on the shape and size of the depressed skull fracture (measured from the CT reformations), we inferred that the man had been stricken by a cylindric blunt object with a diameter of about 3 cm.     

基于深度学习的人体肋骨骨折智能检测技术

目的将人工智能中的深度学习技术应用到人体肋骨骨折识别,实现人体肋骨骨折智能检测,提高法医肋骨骨折诊断效率。方法采集3143例人体胸部X线数字影像(2602例用于训练,541例用于测试),标注肋骨骨折特征点,通过多层网络堆叠,分层、分级主动学习原始数据高度抽象的特征表述,并将此特征反馈至检测器进行骨折检测,输出骨折位置及相应置信度。结果基于深度学习的人体肋骨骨折检测准确率在90%以上。结论基于深度学习的人体肋骨骨折检测准确率较高,可用于辅助法医进行肋骨骨折识别诊断、检验鉴定等,本研究可为人体其他部位骨骼损伤智能检测提供参考。     

Cognitive Impact of Fatigue in Forensic Neuropsychology Context

Physical and mental fatigue are common factors affecting function and recovery in litigated injuries and illnesses. Despite the high prevalence of fatigue-related symptoms and anticipated impact on cognitive functioning, forensic neuropsychological assessments are often challenged by the following approaches to the evaluation of fatigue: (1) confusing physical and mental fatigue; (2) referencing fatigue as a factor in existence but disregarding its specific cognitive impact; (3) over-attribution of all identified problems to fatigue; and (4) neglecting the impact of fatigue on effort in testing. In the context of a wide range of idiosyncratic approaches applied by neuropsychologists with respect to the significance of fatigue factors and the role of the assessor in accounting for them, there is a risk of confusion. Yet, impairments caused by fatigue can be disabling and resistant to treatment, and even more so when the treatment is based on incorrect diagnostic, causality, and prognostic assumptions. The current review will focus on integrating the available empirical evidence from neuroscience and neuropsychology regarding our current understanding of the cognitive impact of fatigue. Our critical review will emphasize the implications of the accumulating new evidence for forensic assessment determinations regarding causality, diagnosis, and impact on function, as well as prognosis and treatment. To this end, electronic search engines including PubMed, PsycINFO, and Google Scholar (up to January 2018) have been screened and reviewed both for the neuroscience and neuropsychological literature related to mental fatigue.     

Chronic Alcohol Abuse Leads to Low Bone Mass with No General Loss of Bone Structure or Bone Mechanical Strength,

Chronic alcohol abuse (CAA) has deleterious effects on skeletal health. This study examined the impact of CAA on bone with regard to bone density, structure, and strength. Bone specimens from 42 individuals with CAA and 42 individuals without alcohol abuse were obtained at autopsy. Dual‐energy X‐ray absorptiometry (DEXA), compression testing, ashing, and bone histomorphometry were performed. Individuals with CAA had significantly lower bone mineral density (BMD) in the femoral neck and significantly lower bone volume demonstrated by thinner trabeculae, decreased extent of osteoid surfaces, and lower mean wall thickness of trabecular osteons compared to individuals without alcohol abuse. No significant difference was found for bone strength and structure. Conclusion: CAA leads to low bone mass due to a decrease in bone formation but with no destruction of bone architecture nor a decrease in bone strength. It is questionable whether this per se increases fracture risk.     

Causality of an accident in subsequent fatal pulmonary embolism a few hours after trauma

An 87-year-old woman, who was largely immobilized in a wheelchair, suffered rib fractures and an unstable fracture of the pelvic ring in a fall. Approximately 2 1/2 hours later she developed marked clinical symptoms of pulmonary thromboembolism and died 5 hours after the accident. The question to be discussed with regard to the causality was the unusually short interval of only 2 1/2 to 5 hours between the accident and the clinical signs of embolism leading to her death. Current literature gives only rough outlines stating that thromboembolism can occur as early as the first day after the trauma. An alternative theory explaining the pulmonary thromboembolism may be the breaking off of a pre-existing thrombus due to manipulation during transport or diagnostic measures in connection with the unstable fracture of the pelvic ring.     

Pontomedullary lacerations in falls from a height--a retrospective autopsy study

Brainstem pontomedullary laceration (PML) in falls from a height appears as isolated cases and usually in feet-first impacts with a ring fracture. The aim of this study was to determine the frequency of PML in falls from a height, as well as the frequency of concomitant head and neck injuries. Out of 261 cases, PML was present in 40. An impact to the chin, as well as a feet- or buttocks-first impact, most often led to PML owing to transmission of the impact force. Also, a lateral, frontal, or posterior head impact, with subsequent hinge fracture, as well as the frontoposterior hyperextension of the head associated with an upper spine fracture, could be possible mechanisms of PML in falls from a height. The jawbone and other facial bones act as shock absorbers, and their fracture diminishes energy transfer toward the skull and protects the brain and brainstem from injury.     

硬脑膜厚度及生物力学参数时序性变化在死亡时间推断中的应用

目的研究人尸体硬脑膜厚度以及生物力学参数与死亡时间(postmortem interval,PMI)的关系,探讨其用于推断PMI的可行性。方法收集尸体检验的硬脑膜样本并按死后6h、12h、18h、24h、30h、36h、48h、60h、72h、84h、96h分组,统一制作成4.0cm×1.0cm的A、B两块试件。测量A试件厚度后检测极限载荷、最大力变形、抗拉强度、弹性模量、断裂力等生物力学参数,分别拟合厚度和生物力学参数值与PMI的回归方程,并通过验证组验证PMI预测值与实际值之间的差异。B试件经10%中性甲醛溶液固定后制备组织切片观察其形态学变化。结果死后6~96h,硬脑膜厚度逐渐减小,胶原纤维从排列清晰逐渐变为相互融合,细胞核数量逐渐变少;硬脑膜厚度、极限载荷、抗拉强度、弹性模量、断裂力呈时序性下降趋势,其中硬脑膜厚度、极限载荷、弹性模量、断裂力与PMI具有相关性(P<0.05)。回代检验中验证组PMI实际值和预测值之间差异无统计学意义(P>0.05)。结论人死后6~96 h的硬脑膜厚度、极限载荷、弹性模量、断裂力呈时序性变化,利用其与PMI的关系建立的回归方程可用于PMI推断。