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991.
Detection of trace quantities of explosive residues plays a key role in military, civilian, and counter-terrorism applications. To advance explosives sensor technology, current methods will need to become cheaper and portable while maintaining sensitivity and selectivity. The detection of common explosives including trinitrotoluene (TNT), cyclotrimethylenetrinitramine, cyclotetramethylene-tetranitramine, pentaerythritol tetranitrate, 2,4,6-trinitrophenyl-N-methylnitramine, and trinitroglycerin may be carried out using a three-step process combining "turn-off" and "turn-on" fluorimetric sensing. This process first detects nitroaromatic explosives by their quenching of green luminescence of polymetalloles (lambda em approximately 400-510 nm). The second step places down a thin film of 2,3-diaminonaphthalene (DAN) while "erasing" the polymetallole luminescence. The final step completes the reaction of the nitramines and/or nitrate esters with DAN resulting in the formation of a blue luminescent traizole complex (lambda(em) = 450 nm) providing a "turn-on" response for nitramine and nitrate ester-based explosives. Detection limits as low as 2 ng are observed. Solid-state detection of production line explosives demonstrates the applicability of this method to real world situations. This method offers a sensitive and selective detection process for a diverse group of the most common high explosives used in military and terrorist applications today. 相似文献
992.
Margaret P. Donaldson Ph.D. William E. Stephens Ph.D. 《Journal of forensic sciences》2010,55(3):738-741
Abstract: The global trade in counterfeit tobacco products is increasingly taking market share from legal brands in many parts of the developed world, with attendant adverse economic, health, criminal, and other societal impacts. Knowing the geographical source is central to developing new strategies for curbing this illicit trade, and here, the potential of environmental pollen extracted from manufactured cigarettes is examined. Two samples representing U.S. and Chinese brands were investigated for their pollen content. Results indicate that tobacco leaf very efficiently captures environmental pollen (about 1800 and 12,600 grains per cigarette, respectively) with no detectable self‐contamination by the tobacco plant. In both cases, the flora is typical of open space environments, but pollen type counts indicate very different distributions of species. This preliminary investigation indicates that palynology has the potential to constrain geographical source(s) of tobacco, particularly if regionally localized species can be recognized among the pollen. 相似文献
993.
Nicole L. Ledbetter M.S. Barbara L. Walton B.S. Pedro Davila B.S. William D. Hoffmann B.S. Richard N. Ernest B.S. Guido F. Verbeck IV Ph.D. 《Journal of forensic sciences》2010,55(5):1218-1221
Abstract: This article presents the novel instrumentation of nanomanipulation coupled to nanospray ionization‐mass spectrometry, which is used to directly probe trace analytes found on individual fibers. The low detection limits and sample volumes associated with nanospray ionization‐mass spectrometry make it the ideal instrument to implement for trace analysis. Nanospray ionization‐mass spectrometry, coupled with the nanomanipulator, allows for the direct probing of trace particulates on fibers. The technique is demonstrated by dissolving an electrostatic particle of cocaine from a fiber, collecting the analyte solution in a nanospray tip, and transferring the tip directly to the mass spectrometer to complete analysis. The utility of this technique is evident through the minimal sample preparation and short analysis time. The use of nanomanipulation coupled to nanospray ionization‐mass spectrometry could improve on current trace particulate analysis by reducing both detection limits and sample size required to complete analysis. 相似文献
994.
Excerpts
Cocaine: a European Union perspective in the global context 相似文献995.
Short BW 《Issues in law & medicine》2010,26(2):91-195
This article completes a study that the author foreshadowed in his previous articles. The Western moral theory that defends the inalienable right to life and liberty--and that therefore forbids all forms of suicide and slavery--is now well known to the author's readers. What is not well known is an answer to the question of whether this theory, in its totality, was part of the original intent of the Thirteenth Amendment to the Constitution of the United States. The theory of the inalienable right to life and liberty was supported by many political philosophers in the seventeenth and eighteenth centuries. Those philosophers and their theory did shape a good deal of the thought of the men who made the Thirteenth Amendment a part of the Constitution. The anti-suicide implication of the theory, however, was not present in the minds of the framers and ratifiers of the Thirteenth Amendment, and therefore was not part of their intent. 相似文献
996.
997.
Hassenteufel P Smyrl M Genieys W Moreno-Fuentes FJ 《Journal of health politics, policy and law》2010,35(4):517-538
In France, Germany, Spain, and the United Kingdom, the decades from the late 1980s to the present have witnessed significant change in health policy. Although this has included the spread of internal competition and growing autonomy for certain nonstate and parastate actors, it does not follow that the mechanism at work is a "neoliberal convergence." Rather, the translation into diverse national settings of quasi-market mechanisms is accompanied by a reassertion of regulatory authority and strengthening of statist, as opposed to corporatist, management of national insurance systems. Thus the use of quasi-market tools brings state-strengthening reform. The proximate and necessary cause of this dual transformation is found in the work of small, closely integrated groups of policy professionals, whom we label "programmatic actors." While their identity differs across cases, these actors are strikingly similar in functional role and motivation. Motivated by a desire to wield authority through the promotion of programmatic ideas, rather than by material or careerist interests, these elite groups act both as importers and translators of ideas and as architects of policy. The resulting elite-driven model of policy change integrates ideational and institutionalist elements to explain programmatically coherent change despite institutional resistance and partisan instability. 相似文献
998.
This study was conducted to determine the degree of discrimination obtained between non-denim blue cotton fibres using visible–UV range microspectrophotometry alone. To this end, samples of fibres were taken from 100, non-denim, blue cotton, outer garments, including t-shirts, trousers and jumpers and subjected to analysis by both visible and UV range microspectrophotometry. The results obtained from the samples of each garment were compared to determine if they ‘matched’ or not. From an initial visual comparison of the garments it was possible to subdivide the samples into two populations consisting of 73 ‘dark blue’ garments and 27 ‘mid-blue’ garments. It was found that of the 73 ‘dark blue’ garments, 22 distinct sub-populations could be distinguished using visible range MSP, this figure being increased to 43 when the analysis was extended into the UV range. In the case of the 27 ‘mid-blue’ garments, 9 distinct sub-populations were discriminated using visible range MSP, this figure being increased to 17 when the analysis was extended into the UV range. The discriminating power (i.e. the number of discriminated pairs divided by the number of possible pairs) of visible range microspectrophotometry was calculated as 0.89 for ‘mid-blue’ garments and 0.87 for ‘dark blue’ garments. Extending microspectrophotometry into the UV range increased discrimination by 7%, giving a discriminating power of 0.96 for both mid and dark blue cotton fibres which was similar to that reported by a previous study where this method was combined with light and fluorescence microscopy.Intra-garment variation was found to be negligible. The implications of this study for casework are discussed and a revised analytical pathway for the comparison of this fibre type/colour combination using microspectrophotometry as a primary screening tool, is proposed. 相似文献
999.
The goal of this paper is to discuss scientific integrity, consumerism, conflicts of interest, and transparency within the context of forensic science. Forensic scientists play crucial roles within the legal system and are constantly under various pressures when performing analytical work, generating reports based on their analyses, or testifying to the content of these reports. Maintaining the scientific integrity of these actions is paramount to supporting a functional legal system and the practice of good science. Our goal is to discuss the importance of scientific integrity as well as the factors it may compromise, so that forensic practitioners may be better equipped to recognize and avoid conflicts of interest when they arise. In this discussion we define terms, concepts, and professional relationships as well as present three case studies to contextualize these ideas. 相似文献
1000.
James R. Jauchem Ph.D. Jennie M. Burns Ph.D. William B. Voorhees M.S. Michael B. Jirjis Ph.D. 《Journal of forensic sciences》2019,64(4):1196-1202
In laboratory studies of the pig Sus scrofa, hematocrit has consistently increased after conducted‐electrical‐weapon (CEW) exposures, possibly due to contraction of the spleen. Splenectomized animals and intact sham control animals were exposed, each for 30 sec, to a benchtop‐produced electrical waveform of net charge levels similar to those of some CEWs. Changes in the blood were compared statistically. Hematocrit increased significantly in both splenectomized and sham animals. There were no significant main‐effect differences between values of hematocrit from the two groups. There were, however, significant interactive effects of time and splenectomy for hematocrit, red blood cell count, and hemoglobin. After peak values were reached for these variables, values returned toward baseline levels more slowly in splenectomized animals. This may have been due to the lack of a spleen to sequester red blood cells (thereby resulting in more cells remaining in the general circulation), unlike sham animals with intact spleens. 相似文献