The application of capillary electrophoresis for enantiomeric separation of N,N-dimethylamphetamine and its related analogs: intelligence study on N,N-dimethylamphetamine samples in crystalline and tablet forms

This paper reports a new capillary zone electrophoresis method for the simultaneous chiral determination of the enantiomers of N,N-dimethylamphetamine (DMA), methamphetamine (MA), ephedrine (E), pseudoephedrine (PE) and methylephedrine (Me-E). In this study, a number of electophoretic parameters were examined and optimized including the choice of chiral selectors, the use of short-chain tetraalkylammonium cations, the effect of chiral selector concentration, buffer concentration, applied voltage and capillary temperature. Heptakis(2,6-di-O-methyl)-beta-cyclodextrin (DM-beta-CD) and tetrabutylammonium (TBA) being the best chiral selector and buffer cation, respectively, the optimized electrophoretic conditions were found to be: 20 mM DM-beta-CD, 50 mM TBAPO(4) at pH 2.5, applied voltage at 30 kV and temperature at 25 degrees C. Under the optimized conditions, all analytes were well separated with resolution factors between 3.3 and 24.0 achieved. Using phentermine as an internal standard, the intra-day (n=8) precisions for the relative migration times and peak areas of all analytes were below 1.09%, while the inter-day precisions (n=12, 6 days) for the relative migration times and peak areas of all analytes were under 3.77%. This method has been applied to the measurement of the enantiomeric purities of the seized DMA samples. The result of the measurement could provide important clues about the possible synthetic pathways of these samples.     

A Study of PCR Inhibition Mechanisms Using Real Time PCR*,†

Abstract: In this project, real time polymerase chain reaction (PCR) was utilized to study the mechanism of PCR inhibition through examination of the effect of amplicon length, melting temperature, and sequence. Specifically designed primers with three different amplicon lengths and three different melting temperatures were used to target a single homozygous allele in the HUMTH01 locus. The effect on amplification efficiency for each primer pair was determined by adding different concentrations of various PCR inhibitors to the reaction mixture. The results show that a variety of inhibition mechanisms can occur during the PCR process depending on the type of co‐extracted inhibitor. These include Taq inhibition, DNA template binding, and effects on reaction efficiency. In addition, some inhibitors appear to affect the reaction in more than one manner. Overall we find that amplicon size and melting temperature are important in some inhibition mechanisms and not in others and the key issue in understanding PCR inhibition is determining the identity of the interfering substance.     

Analysis of cannabis in oral fluid specimens by GC-MS with automatic SPE

Methamphetamine (MA) is the most commonly abused drug in Korea, followed by cannabis. Traditionally, MA analysis is carried out on both urine and hair samples and cannabis analysis in urine samples only. Despite the fact that oral fluid has become increasingly popular as an alternative specimen in the field of driving under the influence of drugs (DUID) and work place drug testing, its application has not been expanded to drug analysis in Korea. Oral fluid is easy to collect and handle and can provide an indication of recent drug abuse.In this study, we present an analytical method using GC–MS to determine tetrahydrocannabinol (THC) and its main metabolite 11-nor-Δ⁹-tetrahydrocannabinol-9-carboxylic acid (THC-COOH) in oral fluid. The validated method was applied to oral fluid samples collected from drug abuse suspects and the results were compared with those in urine. The stability of THC and THC-COOH in oral fluid stored in different containers was also investigated.Oral fluid specimens from 12 drug abuse suspects, submitted by the police, were collected by direct expectoration. The samples were screened with microplate ELISA. For confirmation they were extracted using automated SPE with mixed-mode cation exchange cartridge, derivatized and analyzed by GC-MS using selective ion monitoring (SIM).The concentrations of THC and THC-COOH in oral fluid showed a large variation and the results from oral fluid and urine samples from cannabis abusers did not show any correlation. Thus, detailed information about time interval between drug use and sample collection is needed to interpret the oral fluid results properly. In addition, further investigation about the detection time window of THC and THC-COOH in oral fluid is required to substitute oral fluid for urine in drug testing.     

东亚电子贸易区及电子贸易税制的构建

东亚地区的相互依赖程度日益加深 ,为了促进东亚地区的贸易便捷化 ,使用信息和通讯技术工具构建电子贸易区成为一种必然。在东亚地区建立PAA等电子贸易区是可取的 ,为了建立电子贸易区 ,有必要改进电子商务的法律和税收制度。为了准备对电子商务进行税收激励 ,政府必须营造出一种能够使电子商务得以蓬勃发展的财政氛围 ,而不必单纯考虑其维护公平、可预测的税收体系的职责     

The Role of Forensic Anthropology in the Examination of the Daegu Subway Disaster (2003, Korea)*

Abstract: Meticulous recovery of victims in the Daegu subway disaster was possible, because charred and fragmented victims were left in situ. Because bodies were piled one over another within the train, appropriate methodology during the recovery was critical to identifying the victims. The disaster area was thoroughly documented with notes, photographs, and schematic drawings of the various locations. The recovery team, comprising two medical examiners and one forensic anthropologist, decided when charred body parts and cremated bones were linked to the same individual based on the anatomy and forensic anthropological examination. Without these recovery procedures, it would not have been possible to efficiently harvest representative DNA sample from most of the victims’ body parts. After the entire process of identification, 136 victims were positively identified, and six victims remained unidentified. This study supports the crucial role of forensic anthropologists in the recovery of victims, especially in fire scenes.     

Political Business Cycle in Taiwan—Evidence from Central Government Expenditures

The political business cycle (PBC) refers to the phenomenon of an incumbent utilizing fiscal or monetary policies to create an economic boom before an election so that periodic fluctuations are induced according to election calendars. This article uses panel data from 1992 to 2010 to examine the effect of presidential elections on central government departmental expenditure in Taiwan. The results suggest an opportunistic PBC in Taiwan after the first Taiwanese presidential direct election in 1996. Furthermore, Taiwan’s government expenditure cycles have been significantly stronger in the years of the “new democracy.”     

东北亚安全合作机制国际研讨会主要观点

“东北亚安全合作机制”国际研讨会于2005年8月3-4日在北京召开。会议由中国现代国际关系研究院与福特基金会共同主办,来自中、美、俄、日、韩、朝六国的20多位专家学者,围绕传统同盟关系、六方会谈、双边关系、非传统安全、经济合作与东北亚安全合作,以及建立东北亚安全合作机制的困难和方案等议题进行了广泛、深入的探讨。现将会议一些主要观点摘要选登如下,以飨读者。     

Selection of twenty-four highly informative SNP markers for human identification and paternity analysis in Koreans

A number of DNA marker types suitable for human identification and parentage testing have been developed, of which single nucleotide polymorphisms (SNPs) merit attention as they are abundant, genetically stable, and amenable to high-throughput automated analysis. In this regard, 24 highly informative SNP markers representing each 22 autosome and both sex chromosomes were selected, and the allele and genotype frequencies of these SNPs were determined in a group composed of 30 unrelated Koreans. Based on frequency data from this group, the estimated probability of identity (P(I)) and probability of paternity exclusion (P(E)) with 22 autosomal SNP loci were 1.905x10(-10) and 98.9%, respectively. The SNPs in this study offer a small but highly accurate database that will be an essential reference for SNP-based forensic application in the future.