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This study reports the persistence behaviour of human scalp hairs under a number of different circumstances. The effects of artificial dyeing of hairs, the presence or absence of roots and different types of fabrics on the persistence of hair on a variety of garments were investigated. The garments were made from cotton, polycotton, cotton/acrylic, polyester and wool. The results indicated that neither artificial dyes nor the presence or absence of roots had statistically significant effects on the persistence of hair. In contrast, the type of fabric had a major impact and it was found that, generally, hairs persist longer on rougher fabrics. The rate of loss of hairs from non-woollen fabrics during normal wear was found to follow an exponential decay curve. In contrast, the rate of loss from the woollen garments was quite linear, indicating a constant, even loss, and thus suggests that a different process is involved in the persistence of hairs on woollen garments from that on non-woollen garments. The speed at which hair was lost from fabrics decreased in the order polyester, cotton/acrylic, polycotton, cotton, smooth wool, rough wool, so that wool gives the best chance of recovering samples of hair. Due to the uniqueness of each case, it is advised that caution be used when making any interpretations and before drawing any conclusions.  相似文献   

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利用射击残留物的存在和分布形态判断枪口与射入口的距离是现场分析的关键之一。然而我们在工作中发现,在对头部射击的案件中,弹孔周围的头发有可能对射击残留物起到屏蔽作用,尤其在贴近距离[1](2cm~5cm左右)射击的时候,绝大部分射击残留物会附着在头发而不是头皮上,本文将以实验和真实案例为基础详细说明近距离射击时头发对射击残留物附着的影响。  相似文献   

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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.  相似文献   

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A classification of bone fissures, suggested by the authors, is based on the results of their studies of bone destruction. Relationship between the fissures and bone tissue structural arrangement, and the sequence of the fissure emergence and development, starting from a microfissure (at the level of bone plates) progressing to a major fissure, resulting in final destruction of the bone, underlie this classification.  相似文献   

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The presence of drugs excreted from the body with the perspiration (without stimulation of the sweat glands) and deposed in the linens, was investigated. Linens were obtained from addicts and from smokers. The investigations demonstrated that cocaine, nicotine, cotinine and methadone excreted with the sweat are deposed in the linens. The drugs measurements were performed by radioimmunoassay and revealed by GC/MS.  相似文献   

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Methadone concentrations in human hair of the head, axillary and pubic hair   总被引:2,自引:0,他引:2  
The concentrations of methadone and its metabolites in the hair of the head, axillary and pubic hair obtained from patients receiving a daily maintenance doses, were determined. Comparison of the concentrations provides the highest values in the axillary hair, followed by pubic hair and the hair of the head.  相似文献   

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This study examines the influence of three-layered cranial architecture development upon blunt force trauma (BFT) cranial outcomes associated with pediatric non-accidental injury (NAI). Macroscopic and microscopic metric and morphological comparisons of subadult crania ranging from perinatal to 17 years of age chronicle the ontogenetic development and spatial and temporal variability in the emergence of a mature cranial architecture. Cranial vault thickness increases with subadult age, accelerating in the first 2 years of life due to rapid brain growth during this period. Three-layer differentiation of the cranial tables and diploë initiates by 3–6 months but is not consistently observed until 18 months to 2 years; diploë formation is not well developed until after age 4 and does not manifest a mature appearance until after age 8. These results allow topographic documentation of cortical and diploic development and temporal and spatial variability across the growing cranium. The lateral cranial vault is identified as expressing delayed development and reduced expression of the three-layer architecture, a pattern that continues into adulthood. Comparison of fracture locations from known BFT pediatric cases with identified cranial fracture high-risk impact regions shows a concordance and suggests the presence of a higher fracture risk associated with non-accidental BFT in the lateral vault region in subadults below the age of 2. The absence or lesser development of a three-layered architecture in subadults leaves their cranial bones, particularly in the lateral vault, thin and vulnerable to the effects of BFT.  相似文献   

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Using thin-layer and gas chromatography and mass spectrometry, chloroquine and its major metabolite (monodesethylchloroquine) were identified in hair samples of numerous patients who received this antimalarial drug for several months. In two patients the amounts of chloroquine were, respectively, 310 and 145 mg/kg hair and those of the monodesethylchloroquine 23 and 11 mg/kg. The respective proportions (93 and 7%) are the same in the two subjects. The chloroquine percentage was near those in the spleen or stomach wall after poisoning. Other metabolites in hair are being identified. Hair analysis may provide a good toxicologic and forensic science complement to the blood, urine, and tissues. It may be useful for the control of chloroquine therapy.  相似文献   

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Phenobarbital analysis was performed in vertex hair of patients by gas chromatography mass spectrometry (GC/MS). After washing with dichloromethane, about 250 mg were ground to dust in a ball mill. A 50-mg sample was stirred mechanically for 10 min with 3 ml of NH4Cl/HCl buffer (pH 2.0) containing phenobarbital D5. A solid phase extraction was performed (extrelut Merck) and elution was achieved with chloroform/isopropanol/n-heptane (50:17:33; v/v). A full scan (40–240 uma) acquisition was realized by GC/MS with an ion trap (ITD 700 Finnigan) using a DB5-MS chromatographic column. Quantification was achieved by integrating dominants ions (phenobarbital, 204; phenobarbital D5, 209). Compared to serum, hair concentrates phenobarbital during anti-epileptic therapy (average value 36.4 ng/mg, n = 40 vs. 18.7 mg/l, n = 23). A group correlation exists between phenobarbital in hair and phenobarbital in serum, and between phenobarbital in hair and clinic observation in some typical cases. Phenobarbital in hair yields good information over a long period, especially when blood collection has not been made, when clinical disorders are observed on long-term therapeutic observance.  相似文献   

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Fatty acid ethyl esters (FAEE) can be used as alcohol markers in hair. It was investigated in this study whether this diagnostic method is disturbed by hair care and hair cosmetics. Traces of ethyl myristate, ethyl palmitate, ethyl oleate and ethyl stearate were detected in all of 49 frequently applied hair care products by headspace solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS). The highest concentration was 0.003% in a hair wax. From experiments with separated hair samples of alcoholics as well as from the evaluation of the FAEE concentrations and the data about hair care of 75 volunteers (alcoholics, social drinkers and teetotalers) follows that usual shampooing, permanent wave, dyeing, bleaching or shading are of minor importance as compared to the drinking amount and other individual features. However, false positive results were found after daily treatment with a hair lotion containing 62.5% ethanol, with a deodorant and with a hair spray. As an explanation, it is assumed that FAEE are formed in the sebum glands also after regular topical application of products with a higher ethanol content.  相似文献   

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The sorption of explosives (TNT, RDX, PETN, TATP, EGDN) to hair during exposure to their vapors is examined. Three colors of hair were simultaneously exposed to explosive vapor. Following exposure of hair, the sorbed explosive was removed by extraction with acetonitrile and quantified. Results show that sorption of explosives, via vapor diffusion, to black hair is significantly greater than to blond, brown or bleached hair. Furthermore, the rate of sorption is directly related to the vapor density of the explosive: EGDN > TATP >TNT > PETN > RDX. In some cases, the explosive-containing hair was subject to repeated washings with sodium dodecylsulfate or simply left out in an open area to determine the persistence of the explosive contamination. While explosive is removed from hair with time or washing, some persists. These results indicate that hair can be a useful indicator of explosive exposure/handling.  相似文献   

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毛发中毒品分析   总被引:2,自引:0,他引:2  
毛发分析在法庭毒品分析领域有其独特的优势,很多国家的法化学实验室,毛发分析已成为毒品检测的常规操作,并已得到了法庭的承认、采纳。本文对毒品进入毛发的机制、毛发的现场勘查、毛发中毒品分析程序、毛发中毒品分析结果的评判进行了综述。简单地介绍了毛发在现场勘查中采取、包装、送检的基本方法和技术人员在操作过程中的注意事项,以及针对毛发检验中的特殊技术处理;另外,介绍了毛发中毒品分析的特点,通过分析毛发毒品的药理机制,总结出了一些高效、便利、快速的毒品分析方法,并对各种方法进行了介绍,得出了毛发中毒品分析结果的一些特点。  相似文献   

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Ethyl glucuronide (EtG) is a minor metabolite of ethanol that can be detected in hair. In some specific situations, head hair can be missing, and therefore, alternative anatomical locations of hair are of interest. In this study, paired hair specimens (head hair and pubic hair) from eight social drinkers were analyzed for EtG. Each sample was decontaminated by two dichloromethane bathes (5 ml) for 2 min. After cutting into small pieces, about 50 mg of hair was incubated in 2 ml water in the presence of 10 ng of EtG-d5, used as internal standard and submitted to ultra-sonication for 2 h. The aqueous phase was extracted by SPE using Oasis MAX columns. The hair extract was separated on an ACQUITY BEH HILIC column using a gradient of acetonitrile and formate buffer. Detection was based on two daughter ions: transitions m/z 221-85 and 75 and m/z 226-75 for EtG and the IS, respectively. This laboratory is using a positive cut-off at 50 pg/mg. All eight head hair specimens were negative for EtG at a limit of quantitation fixed at 10 pg/mg. Surprisingly, EtG was identified at high concentrations in pubic hair, in the range 12-1370 pg/mg. It appears, therefore, that it is not possible to document the drinking status of a subject by simply switching from head hair to pubic hair.  相似文献   

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Opiate levels in hair   总被引:1,自引:0,他引:1  
By means of radioimmunoassay-technique, hair samples of users, drug related fatalities, carcinoma patients receiving morphine and of experimental guinea pigs receiving codeine were investigated for opiates. The RIA-investigations require a minimum of material; our routine procedures need only 50 mg of hair. No correlation existed between administered doses of opiates and their concentrations in hair of both human and experimental animals. By sectioning the hair, the approximate period of drug use in man could be detected. However, these findings could not be confirmed by the animal experiments. The growth rate of the hair, diffusion and adhesion processes may influence the transport of drugs along the hair. External contaminations and washing procedures were shown to increase or diminish the drug concentration of the samples.  相似文献   

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