上、下尖牙髓腔/牙体表面积比值的年龄判定价值研究

目的 通过三维重建测量上、下颌尖牙髓腔/牙体表面积比值(Pulp/Tooth area Ratio,PTR)来推断个体年龄,为临床年龄推断的应用提供科学依据.方法 收集口腔门诊患者年龄在16～65岁200例锥形束CT(Cone beam computed tomography,CBCT)影像资料,以4个尖牙为测量对象并...     

Metrological framework for selecting morphological characters to identify species and estimate developmental maturity of forensically significant insect specimens

Accurate age estimates of immature necrophagous insects associated with a human or animal body can provide evidence of how long the body has been dead. These estimates are based on species-specific details of the insects’ aging processes, and therefore require accurate species identification and developmental stage estimation. Many professionals who produce or use identified organisms as forensic evidence have little training in taxonomy or metrology, and appreciate the availability of formalized principles and standards for biological identification. Taxonomic identifications are usually most readily and economically made using categorical and qualitative morphological characters, but it may be necessary to use less convenient and potentially more ambiguous characters that are continuous and quantitative if two candidate species are closely related, or if identifying developmental stages within a species. Characters should be selected by criteria such as taxonomic specificity and metrological repeatability and relative error. We propose such a hierarchical framework, critique various measurements of immature insects, and suggest some standard approaches to determine the reliability of organismal identifications and measurements in estimating postmortem intervals. Relevant criteria for good characters include high repeatability (including low scope for ambiguity or parallax effects), pronounced discreteness, and small relative error in measurements. These same principles apply to individuation of unique objects in general.

Key points

• Metrological rigour can increase in forensic entomology by selecting measurements based on their metrological qualities.
• Selection of high-quality features for morphological identification of organisms should consider these criteria: (1) pronounced discreteness of features (minimising group overlap or maximizing interval); (2) high repeatability of assessment (such as symmetrical width rather than asymmetrical length); (3) small relative error in measurement (selecting the physically largest continuous rigid feature for measurement).
• These metrological principles also apply to individuation of unique objects in general.

     

高职学生心理健康问题分析及教育对策

目前,高职学生心理健康问题呈现递增趋势,已成为严重阻碍大学生健康成长和顺利完成学业的重要因素.如何塑造学生健康完整的人格,使学生在德育、智育、体育、心育得到全面发展,已成为教育工作者共同关注的问题.文章主要从心理健康的内涵、高职学生心理健康问题的表现特征、高职学生心理健康问题的形成因素进行分析、总结,并针对高职学生心理健康问题的现状,提出几点解决和教育的对策.     

基于38-plex InDels的青海地区三个族群遗传推断

目的 基于38-plex InDels族群推断体系研究青海地区汉族、回族及撒拉族的族群成分与遗传结构.方法 使用38-plex InDels复合扩增体系检测3个族群的220份样本并获取InDels位点分型,利用主成分分析、STRUCTURE聚类分析及系统发育树综合分析族群之间的遗传关系,使用族群推断软件DAA v1.0...     

重型犯常见的心理问题及应对策略

重型犯是指犯罪性质恶劣、情节严重以及社会危害性很大的罪犯。用症状自评量表(SCL—90)对重型犯进行了测查,发现入监初期与入监中期服刑人员相比,入监中期服刑人员在躯体化、忧郁、偏执三项因子分方面明显高于入监初期犯人,表明服刑时间较长的罪犯存在更多的心理问题。因此,综合运用各种改造手段对罪犯进行心理和行为矫正,广泛开展心理健康教育,就可以极大地提高我国特殊预防的水平。     

美与生态健康在语境性审美体验中的整合——以伊顿的审美理论为讨论中心

借鉴生态学知识与原理来重新解释审美活动及其一系列关键词是生态美学建构的重要组成部分,针对生态危机这个时代语境来重释"美"的要点则是解释它与"生态健康"的内在关联,其理论难点是将认识性的、不可感知的"生态健康"内容有机地融合到审美体验之中,从而建构出有别于传统之"美"的"生态健康之美",进而将传统的审美体验转化为生态审美...     

Forensic toxicological study on adipocere formation in submerged cadavers of female albino rats intoxicated with cadmium

There is a dearth of information on the mutual interaction between metal intoxication and adipocere formation. Herein, 40 adult female albino rats were distributed into two equal groups, one used as control while the other orally administered single dose of cadmium chloride (CdCl₂) 225 mg/kg·bw (LD_min). Control group was killed by cervical dislocation. Half of dead rats of both groups were subjected for determination of iodine value and estimation of cadmium (Cd) residues while the other half of both groups were submerged in opened glass container previously filled with 4 L dechlorinated tap water kept in closed room with an open air access (one cadaver/container). Gross morphological changes of submerged cadavers were recorded weekly along the experiment. At the end of the experiment, after 3 months, samples were collected again for iodine value determination and estimation of Cd residues. The obtained results revealed the depressant effect of Cd toxicity on development of adipocere. Cd residues were found in different tissues of cadavers at time of death with the highest amount in the intestines followed by the liver and kidneys, then lungs, adipose tissue, muscles, and finally the bones. After 3 months of water submersion, tissues exhibited significant decrease in the amount of Cd residues but to a limit that was still detected. This study concluded the possibility of detection of Cd residues even after adipocere formation. Additionally, it shed light on the possibility of the interference of environmental pollution with the natural rate of decomposition especially adipocere formation.     

Postmortem chest computed tomography for the diagnosis of drowning:a feasibility study

It may be difficult to distinguish the cause of death in drowning cases without specific findings. The aim of this study was to explore the forensic value of thoracic postmortem computed tomography (PMCT) using routine images and three-dimensional (3D) image reconstructions. The imaging data of PMCT examinations of six drowning cadavers, aged 21–54 years, were analyzed. Twelve victims of sudden death from coronary artery disease (CAD) were chosen as a control group. After 3D bilateral lung images were reconstructed using image processing software, an interactive medical image control system was used to measure and analyze parameters including lung volume, lung volume ratio, mean CT value of the whole lung, and lung CT value distribution curves. Lung volume and lung volume ratio were used to assess the shape changes of the lung. Lung CT value distribution curves showed the corresponding number of pixels of the different CT values in the lung image. Lung volume was not significantly larger in drowning cases (mean 2 958 cm³) than in controls (mean 2 342 cm³). Lung volume ratio values in the drowning group (mean 0.3156) were greater than those in the control group (mean 0.2763); (P = 0.02). There was no significant difference between the drowning and control group in the mean CT value of the whole lung. There were differences between lung CT value distribution curves in drowning victims and controls, with drowning victims showing a single peak and CAD cases showing a bimodal distribution. Thoracic PMCT is helpful for the forensic medical diagnosis of drowning. Lung volume ratio and lung CT value distribution are potential indicators to distinguish between drowning and CAD.     

论劳动者安全健康权益的保障

保证生命安全是人的最基本需求。“安全发展”体现了科学发展观“以人为本”的本质特征。目前我国安全生产形势十分严峻,伤亡事故频发、职业危害严重,劳动者安全健康合法权益受到侵害。只有实现安全发展,劳动者的生命安全得到切实保障,社会才能和谐稳定,经济才能持续发展。因此,构建社会主义和谐社会,必须从保障劳动者安全健康切身利益这一现实问题入手。     

Cloud point extraction coupled with back extraction: a green methodology in analytical chemistry

Recently, cloud point extraction (CPE) coupled with back extraction (BE) has been suggested as a promising alternative to liquid-liquid extraction. In CPE, non-ionic surfactants in aqueous solutions form micelles and the solution becomes turbid when heated to the cloud point temperature. Microwave- or ultrasonic-assisted BE can be performed after CPE and before injection of the sample for instrumental analysis by ultraviolet-visible spectroscopy, high-performance liquid chromatography, gas chromatography, gas chromatography-mass spectrometry, or liquid chromatography-mass spectrometry. This article reviews selected published scientific research on the application of CPE-BE to the determination of alkaloids, drugs and organophosphorus compounds from several complex matrices. This method could be scaled-up for use in forensic science.