人体毛发尖部形态的扫描电镜研究

采用扫描电镜观察人体毛发尖部微观形态特征，总结归纳了人体主要几个部位毛发尖部形态的八种类型，探讨各类毛尖形状其形成的可能条件、分布的规律性以及修剪后端部的变化情况，为研究人体毛发生长机理、法庭科学的毛发鉴定工作提供依据。     

大鼠溺死后气管纤毛变化的扫描电镜观察

应用扫描电镜对大鼠溺死后不同时间气管纤毛病理变化进行了观察，发现溺死大鼠气管纤毛局部紊乱，杯状细胞顶端开口增多，纤毛表面粘附有较多的絮网状结构．随死后时间延长，纤毛出现粘结、倒伏、结构破坏、消失等死后变化．结果表明，用扫描电镜观察上述变化有助于溺死死因诊断和死后经过时间的推断．     

毛发常见机械性损伤形态的环境扫描电镜研究

目的建立环境扫描电镜(ESEM)法推断毛发致伤物种类的新方法。方法应用ESEM观察分析不同锐器、钝器及致伤方式形成的毛发机械性损伤的微观形态特征。结果毛发锐器、钝器损伤的表面微观特征存在显著差异,同种类型致伤工具,其锋利程度、作用方式不同时,其损伤特征也明显不同。结论ESEM法能够真实、自然反映毛发机械性损伤表面微观特征,可应用于推断毛发致伤物种类。     

扫描电镜/能谱观察溺死和死后入水的法医学应用研究

目的探讨扫描电镜/能谱分析在溺死的法医学鉴定中的作用。方法实验选用20例已知生前入水尸体,11例已知的死后入水尸体和2例陆地死亡尸体。在每个肺叶各取3个切面,每个切面用扫描电镜取样台胶面与肺叶的切面充分接触,另在落水地点取水样一份,进行对比。扫描电镜取样台胶在切面上充分接触后封闭取材盒,真空干燥后,直接在扫描电镜下进行观察。结果20例生前入水尸体在肺组织中均检出异物颗粒,并且与对照水样中检出的异物颗粒相吻合;而死后入水的尸体和在陆地上死亡的尸体肺组织中均未检出明显的异物颗粒,3者比较P<0.0001。在肺组织支气管切面中,生前入水的20例中有15例检出异物颗粒,在边缘肺切面及中间切面中分别有13例检出异物颗粒,统计学无明显差异。结论本实验建立的肺脏内异物颗粒取材方法准确可靠实用。对综合判断案件的性质,判断溺死尸体入水地点的具有积极意义。较好地解决了实验室检验中的污染问题。腐败尸体对检测结果无影响。     

Study of microinjuries to hair cuticle of human head by scanning electron microscopy

The author presents the data on microclues in the free edges of hair cuticles of human head: microinjuries, microdefects (cracks, breaks, clefts, large and small waves) in representatives of Asia, Africa, Latin America, and Eastern Europe. The studies were carried out by scanning electron microscopy. Microinjuries of cuticle cells forming during hair combing by different types of combs and as a result of "permanent" curling are described. Scanning electron microscopy at the optimal magnification of x 3000 is a highly informative method for investigating microinjuries to the hair cuticle as additional signs in expert evaluation of the hair.     

Registration of fingertip pattern with dental impression materials: A scanning electron microscope study

A scanning electron microscope (SEM) study has been made on fingerprints taken with three dental impression materials and a replica tape. A comparative analysis of the impression materials revealed that clearest SEM images were obtained with a Kerr wax-based, type I Compound. Other advantages of this material are its low cost and convenience in handling. Impression plaster was found to be somewhat inferior to Compound due mainly to the porosity of this material. Xantopren, a silicon-based material, gave excellent resolution. However, this was associated with many artefacts that rendered the specimen difficult to interpret. The replica tape was inappropriate for use with specimens as large as whole fingertips. The advantages of examination with SEM are its three dimensional images and the option of using an image inversion mode for accurate reconstruction of the actual fingertip pattern.     

Identification of wires and the cutting tool by scanning electron microscope

The cut ends of aluminium and copper wires made by different pliers have been compared under the scanning electron microscope to correlate the two pieces of a wire and to identify the cutting tool. The mechanism of producing the cut ends has been discussed. Matching of extrusion marks and correspondence of breakages at the edges of the cut ends were observed. Correspondence between the fine striations was observed on the opposite faces. These features are put forward for assigning a cut wire to a source.The ends produced by repeatedly cutting a wire by the same portion of the edge of a pair of pliers have been compared. It was found that the striations and fracture zones were reproduced on the respective surfaces of the consecutive cut ends. To identify the cutting tool in wire theft cases, it is suggested that the trial cut ends can be made by cutting the wire with successive portions of the edge of the suspected tool and compare the surface features with that on the questioned ones.     

人体血液体外电击致血细胞穿孔的扫描电镜观察

目的探讨血细胞体外电击时细胞膜的结构变化。方法对成人血液分别分组通过220V交流电电击5,10,20,30s和1min后,用扫描电镜观察血细胞膜的变化。结果电击后,即可以观察到红细胞与白细胞的细胞膜穿孔,其中红细胞穿孔可为一个或多个,形状多为圆形或卵圆形,白细胞穿孔则为多个,呈筛网状;穿孔细胞数随电击时间延长而增多;电击5s时为6%左右,以后逐渐增加,至电击1min时,穿孔细胞数可达40%左右。结论电流作用可以使血细胞膜发生穿孔,穿孔细胞数随通电时间延长而增多。     

A measurement of human hair oxidation by Fourier transform infrared spectroscopy

Human scalp hair samples were oxidized to determine the sulfonic acid absorption peak. This peak was monitored at 1044 cm-1 by Fourier transform infrared spectroscopy (FTIR) in hair samples from 135 whites and found to provide a degree of discrimination in treated and untreated hairs. The effects of moisture, laboratory storage, natural hair color, and variation over time were also studied.     

A simple method for detection of gunshot residue particles from hands, hair, face, and clothing using scanning electron microscopy/wavelength dispersive X-ray (SEM/WDX).

We devised a simple and rapid method for detection of gunshot residue (GSR) particles, using scanning electron microscopy/wavelength dispersive X-ray (SEM/WDX) analysis. Experiments were done on samples containing GSR particles obtained from hands, hair, face, and clothing, using double-sided adhesive coated aluminum stubs (tape-lift method). SEM/WDX analyses for GSR were carried out in three steps: the first step was map analysis for barium (Ba) to search for GSR particles from lead styphnate primed ammunition, or tin (Sn) to search for GSR particles from mercury fulminate primed ammunition. The second step was determination of the location of GSR particles by X-ray imaging of Ba or Sn at a magnification of x 1000-2000 in the SEM, using data of map analysis, and the third step was identification of GSR particles, using WDX spectrometers. Analysis of samples from each primer of a stub took about 3 h. Practical applications were shown for utility of this method.     

Morphological study of human hair infected with Microsporum canis

Some aspects in forensic medical examination of hairs damaged by Microsporum canis are discussed. The data of microscopic, fluorescent, and serological studies of damaged hairs and methods for their examination are presented.     

Determination of methadone in human hair by radioimmunoassay

The concentrations of methadone in human hair were measured. The washed hair was cut in 1-mm pieces approximately, then incubated overnight at 45 degrees C with 0.1 m HCl. The extracts were alcalized by 1 m NaOH and diluted by phosphate buffer, pH 7.4. The methadone concentrations were determined by radioimmunoassay. The method is simple, rapid, and practicable for routine determination.     

度冷丁在豚鼠毛发中的分布研究

目的探讨度冷丁在毛发中的分布状况。方法通过动物实验-给豚鼠持续腹腔注射度冷丁,探讨度冷丁在豚鼠毛发中出现与消失的时间过程及注射剂量与毛发中的含量关系。结果给豚鼠隔日连续腹腔注射度冷丁7次,第4天可在豚鼠毛发中检出度冷丁,第8天达浓度高峰,停止注射后第5天检不出度冷丁;豚鼠毛发中度冷丁含量与度冷丁的注射剂量有关,但无明显的线性关系。结论研究结果为实际案例分析结果的评价提供依据。     

A comparison study of hair examination methodologies

A study was conducted to investigate the accuracy between two methods of hair analysis: PCR-STR DNA analysis and microscopic comparison analysis. Standard sets of pubic hairs were collected from volunteers, and unknown sets were generated from these samples. Three out of five (60%) of the hairs analyzed produced full DNA profiles that were correctly matched to the standard sets. DNA analysis was inconclusive (partial or no DNA profile) for two out of five (40%) of the samples. In contrast, the microscopic comparison analysis correctly matched four out of five (80%) of the samples to the standard sets but mis-identified one out of five (20%) of the samples. These results reinforce the practice of preliminary microscopic hair examination in narrowing down a set of hairs for DNA analysis. Microscopic comparison analysis is sufficiently reliable to remain a rapid and inexpensive method for forensic hair analysis.     

人牙咬痕形态学变化动态过程研究

目的　研究人牙咬痕形态学变化的动态过程 ,了解咬痕发生、发展的变化规律 ,为已发生变化的咬痕同一认定提供依据。方法　动态追踪观察活体及死亡动物咬痕的变化过程 ,并测定其相关形态参数 ,多元逐步回归分析咬痕形态、牙面积、时间、牙合力、牙宽度、牙厚度之间的关系 ,建立咬痕形态学变化回归方程。结果　咬痕的形态、牙形态、时间、牙合力有一定的数学关系 :S =-6 96-1 68× 10 2 T -0 11F +2 2 1W +3 75H (活体狗实验T <3 60min) ;S =-2 1 90 +5 3 4× 10 2 T -0 3 6F +4 5 7W +6 66H (死亡狗实验T <14 40min)。     

Use of solid-phase microextraction (SPME) for the determination of methadone and EDDP in human hair by GC-MS

Solid-phase microextraction (SPME) is a new extraction technique with many advantages: small sample volume, simplicity, quickness and solvent-free. It is mainly applied to environmental analysis, but is also useful for the extraction of drugs from biological samples. In this paper the use of SPME is proposed for the determination of methadone and its main metabolite EDDP in hair by GC-MS. The hair samples were washed, cut into 1-mm segments, and incubated with Pronase E for 12 h. A 100-micron polydimethylsiloxane (PDMS) film fibre was submerged for 30 min in a diluted solution of the hydrolysis liquid (1:4 with borax buffer) containing methadone-d3 and EDDP-d3 as internal standards. Once the microextraction was concluded the fibre was directly inserted into the CG injection port. Linearity was found for methadone and EDDP in the range studied, 1.0-50 ng/mg hair, with correlation coefficients higher than 0.99. Interassay relative standard deviation (R.S.D) was determined to be less than 13.30% for methadone and less than 8.94% for EDDP, at 3.0 and 30.0 ng/mg. Analytical recoveries were close to 100% for both compounds on spiked samples. The method was applied to the analysis of real hair samples from eight patients of a methadone maintenance programme. The concentration of methadone in hair ranged from 2.45 to 78.10 ng/mg, and for EDDP from 0.98 to 7.76 ng/mg of hair.