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121.
Eckenrode BA Ramsey SA Stockham RA Van Berkel GJ Asano KG Wolf DA 《Journal of forensic sciences》2006,51(4):780-789
The Scent Transfer Unit (STU-100) is a portable vacuum that uses airflow through a sterile gauze pad to capture a volatiles profile over evidentiary items for subsequent canine presentation to assist law enforcement personnel. This device was evaluated to determine its ability to trap and release organic compounds at ambient temperature under controlled laboratory conditions. Gas chromatography-mass spectrometry (GC-MS) analyses using a five-component volatiles mixture in methanol injected directly into a capture pad indicated that compound release could be detected initially and 3 days after the time of collection. Additionally, 15 compounds of a 39-component toxic organic gaseous mixture (10-1000 parts per billion by volume [p.p.b.(v)]) were trapped, released, and detected in the headspace of a volatiles capture pad after being exposed to this mixture using the STU-100 with analysis via GC-MS. Component release efficiencies at ambient temperature varied with the analyte; however, typical values of c. 10% were obtained. Desorption at elevated temperatures of reported human odor/scent chemicals and colognes trapped by the STU-100 pads was measured and indicated that the STU-100 has a significant trapping efficiency at ambient temperature. Multivariate statistical analysis of subsequent mass spectral patterns was also performed. 相似文献
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A method was developed for simultaneously analyzing cocaine (COC), benzoylecgonine (BZE), norbenzoylecgonine (BNE), norcocaine (NCOC), ecgonine (ECG), ecgonine methyl ester (EME), m-hydroxybenzoylecgonine (HBZE), anhydroecgonine methyl ester (AEME), cocaethylene (CE), norcocaethylene (NCE), and ecgonine ethyl ester (EEE) in blood, urine, and muscle. Available deuterated analogs of these analytes were used as internal standards. Proteins from blood and muscle homogenate were precipitated with cold acetonitrile. After the removal of acetonitrile by evaporation, the supernatants and urine were subjected to solid-phase extraction. The eluted analytes were converted to their hydrochloride salts and derivatized with pentafluoropropionic anhydride and 2,2,3,3,3-pentafluoro-1-propanol. The derivatized products were analyzed by a gas chromatograph (GC)/mass spectrometer by selected ion monitoring. The limit of detection (LOD) for COC, BZE, NCOC, EME, CE, NCE, and EEE was 2ng/ml, while the LODs for BNE, ECG, HBZE, and AEME were 25, 640, 50, and 13 ng/ml, respectively. This method was successfully applied in analyzing 13 case samples from aviation accident pilot fatalities and motor vehicle operators. AEME concentrations found in the 13 samples were consistent with those produced solely by the GC inlet pyrolysis of COC controls in blood. Anhydroecgonine cannot be used as a marker for the abuse of COC by smoking because it is also pyrolytically produced from COC metabolites on the GC inlet. The developed method can be effectively adopted for analyzing COC and related compounds in urine, blood, and muscle by a single extraction with increased sensitivity through formation of hydrochloride salts and using a one-step derivatization. 相似文献
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Prevention science,drug abuse prevention,and Life Skills Training: Comments on the state of the science 总被引:1,自引:0,他引:1
Gilbert?J.?BotvinEmail author Kenneth?W.?Griffin 《Journal of Experimental Criminology》2005,1(1):63-78
There has been tremendous growth in the field of prevention science over the past two decades. The defining features of contemporary prevention science are high quality empirical research using rigorous and well-established scientific methods, careful hyphothesis testing, and the systematic accumulation of knowledge. One area where substantial progress has been made is in our understanding of the etiology and prevention of tobacoo, alcohol, and illicit drug abuse. In this paper, we review the growth in prevention as a scientific enterprise, discuss advances in drug abuse prevention research, and review the effectiveness of one approach to the problem of adolescent drug abuse, the Life Skills Traning (LST) program, and the methodological strengths of the LST evaluation research. In addition, we provide a response to criticism regarding two types of data analysis in evaluation research, and show that these analyses can help address a number of important research questions with implications for theory and practice. First, the analysis of high fidelity subsamples can address research questions about the importance of program implementation fidelity; and second, composite measures of concurrent tobacco, alcohol, and marijuana use (i.e., polydrug use) are useful in testing research questions about program effects on more serious levels of drug involvement. With an increasing number of ramdomized controlled trials underway, the field of prevention science is contributing to a new generation of evidence-based approaches and policies that, if widely utilized, offer the potential of reducing the mortality and morbidity associated with a number of major health and social problems. 相似文献
129.
Dennis T. Avery 《Society》2007,44(6):137-143
High-yield farming—more agricultural output per acre of farmland—has been a boon to mankind and to nature. If today’s agricultural
efficiency was the same as in the 1950s, the world would need three times the cropland to produce today’s food supply. That
would mean that 15-16 million mi2 of forest would have been destroyed—all the global forest area available today. Rising population and increased affluence
will require a tripling of agricultural efficiency in the next 50 years if we are to protect wildlife at the same time. More
investment in agricultural research and education will be required, but this is what produced the previous green revolution.
相似文献
Dennis T. AveryEmail: |
130.
Dennis C. Mueller 《Public Choice》2012,152(1-2):47-60
Gordon Tullock is one of the founders of the field of public choice, of the Public Choice Society, and of the Public Choice Center. He is a coauthor with James M. Buchanan of one of the true classics in the public choice field—The Calculus of Consent. He has been one of the field’s most prolific scholars, with his research spanning virtually all dimensions of the public choice field. This article surveys his major contributions. 相似文献