In vitro production of GHB in blood and serum samples under various storage conditions

The in vitro production of GHB was observed in freshly collected, untreated whole blood samples using glass BD-Vacutainers and polypropylene S-monovettes. GHB concentrations were determined daily over a period of one week and after 3, 6 and 9 weeks again. Furthermore, the GHB concentration in 40 untreated random whole blood samples stored at 4°C for a longer period of time (10 samples 12 month, 10 samples 24 month and 20 samples 36 month) was also determined. For comparison, the in vitro production of GHB in freshly collected and prepared serum samples was observed. GHB serum concentrations were determined three times over a period of one week and once again after six weeks. Sample preparation was performed by means of methanolic extraction following the precipitation of whole blood and serum samples. A methanolic standard calibration was done in a low range of 0.005-0.1 μg/mL (LOD: 0.004, LLOQ: 0.013). For quantification a spiked blood bank serum with a determined GHB concentration of 0.09 μg/mL was used. Corrected calibrations in the range of 0.09-5.09 μg/mL were used (LOD: 0.08 μg/mL, LLOQ: 0.30 μg/mL), recovery: 91.3% (high level: 4.09 μg/mL) 50.5% (low level: 0.19 μg/mL). RESULTS: Relevant elevation of GHB was observed in all whole blood samples stored in liquid form (4°C or room temperature). In two of the 40 whole blood samples stored over a longer period of time at 4°C, GHB concentrations in the range of 13 μg/mL were even determined. These findings constitute grounds for caution. Even a GHB cut-off level of 5 μg/mL cannot be considered as "absolutely positive" proof of a case of exogenous administration, at least in untreated liquid blood samples in long time storage. However, no significant elevations of GHB were otherwise observed in any of the serum samples independently of storage temperature nor in the whole blood samples that were frozen for storage. CONCLUSIONS: The results suggest that the cut-off for exogenous GHB of 5 μg/mL could be lowered significantly, with the consequence of winning valuable time for the potential victim, but only if serum is collected for GHB determination or if the whole blood sample is frozen immediately after collection and the procedure well documented.     

Raman spectroscopy and microspectrophotometry of reactive dyes on cotton fibres: Analysis and detection limits

A collaborative study on Raman spectroscopy and microspectrophotometry (MSP) was carried out by members of the ENFSI (European Network of Forensic Science Institutes) European Fibres Group (EFG) on different dyed cotton fabrics. The detection limits of the two methods were tested on two cotton sets with a dye concentration ranging from 0.5 to 0.005% (w/w). This survey shows that it is possible to detect the presence of dye in fibres with concentrations below that detectable by the traditional methods of light microscopy and microspectrophotometry (MSP). The MSP detection limit for the dyes used in this study was found to be a concentration of 0.5% (w/w). At this concentration, the fibres appear colourless with light microscopy. Raman spectroscopy clearly shows a higher potential to detect concentrations of dyes as low as 0.05% for the yellow dye RY145 and 0.005% for the blue dye RB221. This detection limit was found to depend both on the chemical composition of the dye itself and on the analytical conditions, particularly the laser wavelength. Furthermore, analysis of binary mixtures of dyes showed that while the minor dye was detected at 1.5% (w/w) (30% of the total dye concentration) using microspectrophotometry, it was detected at a level as low as 0.05% (w/w) (10% of the total dye concentration) using Raman spectroscopy. This work also highlights the importance of a flexible Raman instrument equipped with several lasers at different wavelengths for the analysis of dyed fibres. The operator and the set up of the analytical conditions are also of prime importance in order to obtain high quality spectra. Changing the laser wavelength is important to detect different dyes in a mixture.     

Sexual Dimorphism in Finger Ridge Breadth Measurements: A Tool for Sex Estimation from Fingerprints

Previous research has demonstrated significant sexual dimorphism in friction ridge skin characteristics. This study uses a novel method for measuring sexual dimorphism in finger ridge breadths to evaluate its utility as a sex estimation method from an unknown fingerprint. Beginning and ending in a valley, the width of ten parallel ridges with no obstructions or minutia was measured in a sample of 250 males and females (N = 500). The results demonstrate statistically significant differences in ridge breadth between males and females (p < 0.001), with classification accuracy for each digit varying from 83.2% to 89.3%. Classification accuracy for the pooled finger samples was 83.9% for the right hand and 86.2% for the left hand, which is applicable for cases where the digit number cannot be determined. Weight, stature, and to a lesser degree body mass index also significantly correlate with ridge breadth and account for the degree of overlap between males and females.     

固根萃取技术在系统药、毒物分析中的应用

根据反相色谱法及离子交换色谱法的原理,研制了一种固相萃取小柱,建立了筛分系统,可以同时完成对复杂体系中酸性、中性及碱性药、毒物的一次革取净化及富集,适应于系统毒物及药物筛分工作的需要。并对筛分柱的草取机理进行了初步的实验论证。     

人体组织ABO血型检测方法的研究

探讨人体组织ABO血型检测方法。对已知ABO血型尸体的不同组织,用红细胞粘连试验、吸收—抑制试验和吸收－解离试验进行ABO血型测定。12例尸体的16种组织中均检出与尸体血痕相同的ABH物质。对不同温度保存的组织块进行ABH物质检测的结果显示,4℃保存的组织ABH物质的检出时间长于室温,空腔脏器的检出时间短于实质脏器。三种方法中,红细胞粘连试验简单易行,适用于基层单位,吸收－抑制试验用于组织块的测定时优于吸收－解高试验。     

VNTR D17530位点多态性在亲子鉴定中的应用

运用微量热启动PCR技术,对20例正常家系的遗传学分析,证实D17530位点的遗传符合孟德尔遗传规律,表现为简单的共显性遗传。同时,对100例亲子鉴定案例进行回顾性分析研究,证明D17S30位．在多态性可应用于我国法医学亲子鉴定。根据D17S30位点基因频率估算的排除概率（74．04％）与其实际排除能力（80．00％）无显著差异。在15倒排除亲子关系的案例中,有2例由D17S30位点单独取得排除证据。D17S30位点是法医学上有重要意义的遗传学标记,可用于亲子鉴定。     

Neuropsychological,Psychological, and Vocational Assessment of High Achievers in a Medicolegal Context

High achievers are a unique subset of persons referred for neuropsychological and psychological assessments in medicolegal contexts, including personal injury, disability, and workers’ compensation cases. Literature in this area is limited and poorly integrated, and neither a conceptual model nor best evidence-informed practices for the assessment of high achievers in the medicolegal context have yet emerged. Construct and methodological issues also hamper the ability of assessors to accurately and fairly assess this specialist group, which is particularly troubling in high-stakes forensic assessments. This paper reviews the current methodological issues involved in the assessment of high achievers and proposes an integrated, multimethod assessment model based on a particular vocational group, namely that of business leaders and entrepreneurs, that draws from available empirical research in different fields of psychological inquiry.     

The Decline of Federalism and the Rise of Morality-Policy Conflict in the United States

Morality policies-such as those pertaining to abortion, capitalpunishment, gambling, gay rights, pornography, and sex education—generateconflict over core values. These policies tend to be technicallysimple, potentially salient to the general public, and involvehigher than normal levels of citizen participation. They are,therefore, highly susceptible to being thrust into the activephase of policymaking when an incongruity develops between publicopinion and public policy. The reservation of authority to thestates on these issues embodied in the Tenth Amendment to theU.S. Constitution allows for closer policy-opinion congruence,therefore stabilizing morality policy politics. However, recentfederal actions on a range of morality policies have thrustthese issues onto the active political agenda of the states.     

Measuring the impact of fair trade on development

This study of the impact of fair trade relies on new field data from coffee and banana co-operatives in Peru and Costa Rica, including a detailed assessment of its welfare effects by comparing FT farmers with non-FT farmers as a benchmark. Attention is focused on three major effects: (a) direct tangible impact of FT arrangements on the income, welfare, and livelihoods of rural households; (b) indirect effects of fair trade for improving credit access, capital stocks, investments, and attitudes to risk; and (c) institutional implications of fair trade for farmers' organisations and externalities for local and regional employment, bargaining, and trading conditions. Although direct effects in terms of net income remain fairly modest, important benefits are found to include capitalising farmers and strengthening their organisations.