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The inhalation of heroin vapors after heating on aluminium foil ("chasing the dragon") is gaining popularity nowadays among heroin users seeking to avoid the risks of parenteral drug administration. The heroin-smoking procedure was simulated under laboratory conditions by heating the samples on aluminium foil at 250 to 400 degrees C and collecting the vapors in a condenser trap. A total of 72 pyrolysis products of diacetylmorphine, street heroin, residues from aluminium foils used to smoke street heroin, typical by-products, and adulterants were detected by gas chromatography/mass spectrometry (GC/MS). About half of these compounds could be identified. Diacetylmorphine (base and salt) undergoes substantial to complete degradation. Some typical street heroin constituents, like morphine, codeine, acetylcodeine, papaverine, and caffeine, are rather heat-stable. Other compounds, like noscapine and paracetamol, are pyrolyzed to a greater extent. The principal chemical reactions leading to the formation of pyrolysis products are desacetylation, transacetylation, N-demethylation, O-methylation, ring cleavage and oxydation. 相似文献
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This paper presents a longitudinal study of alcohol use among college students. Three hypothesized predictors of alcohol use are found to have an independent effect when the other predictors and prior drinking are held constant: the drinking context of the dormitory living group, informal social involvement in college, and lack of commitment to religious and academic values. These predictors are also related to the onset of drinking during the freshman year for those who entered college as abstainers. The pattern varies somewhat for males and females, with the dormitory contextual effect larger for females. Formal involvement in college activities and psychological stress have no independent effect on drinking. The results are discussed in relation to previous work on alcohol use.This research was supported in part by NIAAA Grant AA02863 and NIMH Grant MH28177 and Veterans Administration Research funds.Received Ph.D. in sociology from Stanford University in 1976. Current research interests include adolescent development, statistics, and environmental studies.Received Ph.D. in psychology from University of California, Berkeley, in 1960. Current research interests are personal and environmental influences on behavior. 相似文献
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Die europ?ische Fischerei muss sich zur Zeit einer Vielzahl von Problemen wie sinkenden Fangmengen, abnehmenden Ums?tzen sowie
einem stetigen Besch?ftigungsabbau stellen. Einer der Hauptgründe für diese Entwicklung ist die bis zum heutigen Tage nicht
nachhaltig betriebene Fischerei. Mit einer grundlegenden Reform der Gemeinsamen Fischereipolitik (GFP) im Jahre 2002 und der
Abl?sung der alten FischereigrundVO von 1993 sollten diese dr?ngenden Probleme angegangen werden. Darüber hinaus wurde mit
den Regionalbeir?ten (RACs) ein gemeinsames Forum für den Fischereisektor sowie Umweltund Verbraucherschützer geschaffen,
welches die EU-Kommission in Fischereifragen beraten soll. Leider stimmen die ersten Jahre der neuen GFP wenig zuversichtlich.
Eine Erholung der bedrohten Fischbest?nde ist vorerst nicht in Sicht, insbesondere weil die wissenschaftlichen Empfehlungen
der Fischereiexperten weiterhin ignoriert werden. Ob die neu geschaffenen RACs mit ihrer Beratungst?tigkeit und ihrem internen
Diskurs wichtige Anregungen hin zu einer nachhaltigeren Fischerei leisten k?nnen, ist zweifelhaft. 相似文献
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Services Negotiations in the Doha Round: Lost in Flexibility? 总被引:2,自引:0,他引:2
The World Trade Organization (WTO) rules for services trade,under the General Agreement on Trade in Services (GATS), arefar broader in policy coverage than their counterpart provisionsunder the General Agreement on Tariffs and Trade (GATT), reflecting,inter alia, the Agreements extension to cross-bordermovements of services consumers and factors of production. Atthe same time, the GATS is significantly more flexible in applicationthan the GATT. There are virtually no political sensitivities,protectionist or not, that could not be formally accommodatedwithin its structure. Moreover, the paucity of relevant jurisprudenceon key concepts and a yet incomplete rule-making agenda haveprovided additional scope for creative interpretation.However, while flexibility was a sine qua non for the conclusionof the Agreement, given the diversity of institutional conditions,political concerns, and so on among participants, it has notbeen conducive to one of the key objectives: early achievementof progressively higher levels of liberalization. Thisarticle discusses possible approaches that, within the Agreementscurrent structure, could promote the clarity, quantity, andcommercial relevance of services commitments and address remainingrule-making issues. However, there is no panacea. The challengeremains to find a reasonable balance between economically meaningfuldisciplines and their broad application across sectors, modesof supply, and WTO Members. 相似文献
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Jessica Skinner PhD Natalie Langley PhD Malin Joseph MS James Herrick MSA Robert Brown BS Brian Waletzki BS Peter Goguen Dipl T Loukham Shyamsunder PhD Subramaniam Rajan PhD 《Journal of forensic sciences》2023,68(3):757-767
Forensic fractographic features of bone reliably establish crack propagation in perimortem injuries. We investigated if similar fracture surface features characterize postmortem fractures. Experimentally induced peri- and postmortem fractures were used to assess if fractographic features vary as bone elasticity decreases during the postmortem interval (PMI). Thirty-seven unembalmed, defleshed human femoral shafts from males and females aged 33–81 years were fractured at varying PMIs with a drop test frame using a three-point bending setup and recorded with a high-speed camera. Vital statistics, cause of death, PMI length, temperature, humidity, collagen percentage, water loss, fracture energy, and fractography scores were recorded for each sample. Results showed that fractographic features associated with perimortem fractures were expressed in PMIs up to 40,600 accumulated degree hours (ADH), or 60 warm weather days. Hackle was the most consistently expressed feature, occurring in all fractures regardless of ADH. The most variable characteristics were wake features (78.4%) and arrest ridges (70.3%). Collagen percentage did not correlate strongly with ADH (r = −0.04, p = 0.81); however, there was a strong significant correlation between ADH and water loss (r = 0.74, p < 0.001). Multinomial logistic regression showed no association between fractographic feature expression and ADH or collagen percentage. In conclusion, forensic fractographic features reliably determine initiation and directionality of crack propagation in experimentally induced PMIs up to 40,600 ADH, demonstrating the utility of this method into the recent postmortem interval. This expression of reliable fractographic features throughout the early PMI intimates these characteristics may not be useful standalone features for discerning peri- versus postmortem fractures. 相似文献
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Dipl.-Verw.wiss. Christina Eder 《Politische Vierteljahresschrift》2010,51(1):43-67
Between 1990 and 2005, eleven referenda took place in the German Länder. Of these initiatives, seven were accepted by the voters, while the remaining four were unsuccessful. This pattern raises the question as to whether certain factors lead to increased likelihood of success at the ballot-box. Using Qualitative Comparative Analysis (QCA), the following analyses demonstrate that, taken separately, none of the conditions examined in this article have positive effects on the chances of popular endorsement. Instead, a certain combination of conditions seems to be associated with successful initiatives. 相似文献