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841.
Gamma hydroxybutyric acid (GHB) concentrations in humans and factors affecting endogenous production
Elliott SP 《Forensic science international》2003,133(1-2):9-16
The endogenous nature of the drug of abuse gamma hydroxybutyric acid (GHB) has caused various interpretative problems for toxicologists. In order to obtain data for the presence of endogenous GHB in humans and to investigate any factors that may affect this, a volunteer study was undertaken. The GHB concentrations in 119 urine specimens from GHB-free subjects and 25 urine specimens submitted for toxicological analysis showed maximal urinary GHB concentrations of 3mg/l. Analysis of 15 plasma specimens submitted for toxicological analysis detected no measurable GHB (less than 2.5mg/l). Studies in a male and female volunteer in which different dietary food groups were ingested at weekly intervals, showed significant creatinine-independent intra-individual fluctuation with overall urine GHB concentrations between 0 and 2.55, and 0 and 2.74mg/l, respectively. Urinary concentrations did not appear to be affected by the particular dietary groups studied.The concentrations measured by gas chromatography with flame ionisation detection (GC-FID) and gas chromatography with mass spectrometry (GC-MS) lend further support to the proposed urinary and plasma interpretative cut-offs of 10 and 4mg/l, respectively, where below this it is not possible to determine whether any GHB detected is endogenous or exogenous in nature. 相似文献
842.
Agg KM Craddock AF Bos R Francis PS Lewis SW Barnett NW 《Journal of forensic sciences》2006,51(5):1080-1084
A rapid method for screening drug seizure samples for 3,6-diacetylmorphine (heroin), which consists of a simple hydrolysis procedure and flow-injection analysis with two chemiluminescence reagents, is described. Before hydrolysis, 3,6-diacetylmorphine evokes an intense response with a tris(2,2'-bipyridyl)ruthenium(III) reagent (prepared by dissolving the perchlorate salt in acetonitrile), and a relatively weak chemiluminescence response with a second reagent: potassium permanganate in an aqueous acidic polyphosphate solution. However, the permanganate reagent is extremely sensitive toward the hydrolysis products of 3,6-diacetylmorphine (i.e., 6-monoacetylmorphine and morphine). Some compounds commonly found in drug laboratories may cause false positives with tris(2,2'-bipyridyl)ruthenium(III), but do not produce the markedly increased response with the permanganate reagent after the hydrolysis procedure. The combination of these two tests therefore provides an effective presumptive test for the presence of 3,6-diacetylmorphine, which we have verified with 14 samples obtained from a forensic science laboratory. 相似文献
843.
Many suspected victims of surreptitious drug and/or alcohol administration may present to hospitals or healthcare centres and never come to the attention of forensic or law enforcement professionals. Therefore, it is necessary to include clinical toxicological findings in order to assess the growing perception that instances have become more widespread within society. Between July 2002 and June 2004, 180 requests were received for toxicological analysis of individuals presenting to their GP or hospital following self-reported or suspected surreptitious drug administration (e.g. "spiked drink"). There was a rise of 77% in the number of requests from 2002-2003 to 2003-2004 which peaked in December of each year (most likely due to the increased socialization of people during the festive season). Between 2002 and 2004, 34% of patients were male and 66% were female with an overall average age of 25 (range 11-73). Following urinary analysis using immunoassay and gas chromatography (mass spectrometry, flame-ionisation detection and nitrogen-phosphorus detection), 59% of cases were negative for drugs and alcohol in 2002-2003 and 51% in 2003-2004. Drugs or alcohol were detected in 32% of cases in 2002-2003 and in 45% in 2003-2004. Out of the 169 cases analysed, ethanol (alcohol) was the most commonly detected compound (24% of cases), followed by amphetamines (amphetamine, MDMA, MDA, MDEA--11% of cases), cannabinoids (9% of cases), benzodiazepines (temazepam, nordiazepam, oxazepam--9% of cases), cocaine (4% of cases), opiates (dihydrocodeine, codeine--2% of cases), chlorpheniramine (0.6% of cases), ephedrine 0.6% of cases), fluoxetine (0.6% of cases), tramadol (0.6% of cases) and zopiclone (0.6% of cases). No gamma-hydroxybutyrate (GHB), gamma-butyrolactone (GBL) or flunitrazepam was detected in the cases analysed. 相似文献
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847.
Simon M. Fass 《Journal of policy analysis and management》1985,4(4):554-572
As the ongoing debate among philosophers and social scientists suggests, interpretation of cause and effect in human action is often extremely difficult. Especially complicated for the policy analyst is the problem of determining whether causal relationships are inferred from the evidence or imputed to it. This dilemma characterizes certain types of government activity in which distinctions between policy and implementation, between decisions and actions, and between inputs and outcomes are unclear. The efforts of the federal government between 1960 and 1985 to assist refugees in securing employment illustrate how the flow of events may elude causal explanation, and how conclusions and recommendation for improvement derived from the evidence may prove highly ambiguous. In such instances the most rational course open to policy analysts may be to concede ignorance. 相似文献
848.
Julian L. Simon 《Society》1991,28(5):58-62
His books include The Economics of Population Growth; The Ultimate Resource; Theory of Population and Economic Growth: Effort, Opportunity
and Wealth; The Economic Consequences of Immigration;and most recently Population Matters: People, Resources, Environment and Immigration,published by Transaction. 相似文献
849.
850.