• The Journal of Korean Society for School & Community Health Education
• /
• v.10 no.2
• /
• pp.55-68
• /
• 2009

연구목적: 본 연구는 미국 인디애나 주에 소재하는 중학교와 고등학교 학생들 사이의 methamphetamine, MDMA, GHB, and Rohypnol과 같은 약물사용 특성을 파악하고 청소년 약물사용과 관련된 성과 학교 환경에 대한 인지된 안전도 특성을 분석하였다. 연구방법: 본 분석에 사용된 데이터는 Indiana Prevention Resource Center (IPRC)에서 2007 년도에 수행한 음주, 흡연, 약물사용 설문조사(ATOD) 응답자료로서 인디애나 주에 거주하고 있는 6-12 학년 사이의 학생들을 편의추출하여 조사가 가능했던 158,632명의 응답을 얻었다. 연구결과: 로지스틱 회귀분석에서 조사한 4개 약물을 사용하는 학생들의 관심도는 교실에 있을 때, 복도에서 혼자 있을 때, 방과후 활동을 위해 학교에 남아있을 때 불안전하다고 느끼는 약물 미사용자보다 더 높은 경향을 보였다. GHB, MDMA, Rohypnol을 사용한다고 응답한 학생이 여자보다 남자에서 더 많았고 상관관계분석 결과, 메탐페타민을 비롯한 네 가지 약물 사용의 상호간 상관도가 모두 유의미하게 높았다.

• YAKHAK HOEJI
• /
• v.47 no.5
• /
• pp.266-270
• /
• 2003

We evaluated four commercially available methamphetamine immunoassays for their relative cross-reactivities of amphetamine analogues in human urine: Abbott TDx, Vitalab Selectra and on-site test kits (Accusign MET, SD bioline MET). High cross-reactivities were shown at designer's drugs such as methylenedioxyamphetamine (MDA), methylenedioxymethamphetamine (MDMA) and methylenedioxyethylamphetamine (MDEA) in all of the tested immunoassays. Methoxyphenamine, fenfluramine and phentermine were positive in TDx and Selectra, but were not positive in on-site test kits. Pseudoephedrine, norpseudoephedrine, ephedrine, norephedrine, MDMA, MDA, fenfluramine and phentermine were detected by gas chromatography/mass spectrometry(GC/MS) in false positive urines. Since the overall specificity of any of the devices was not 100％, we found it is important to confirm any positive screening test result, so we developed simultaneous determination of amphetamine analogues in urines. After alkalinization of the urine samples with 6-N NaOH, the analytes were extracted using ethyl acetate, derivatized with pentafluoropropyl anhydride (PFPA) prior at GC/MS analysis.

• Proceedings of the PSK Conference
• /
• 2001.04a
• /
• pp.220.3-221
• /
• 2001

• Proceedings of the PSK Conference
• /
• 2003.04a
• /
• pp.169.2-169.2
• /
• 2003

A method using EI-GC-MS is described for the determination of amphetamines in hair. The method is applied to simultaneous quantify amphetamines (methamphetamine, amphetamine, MDMA and MDA). Drugs were extracted in 1 ％ HCl in methanol from hair. After derivertization with TFAA, the resulting drugs were separated on HP-5MS column during a 16 min program and identified by mass spectrometry with the SIM mode(EI-GC-MS). (omitted)

• Mass Spectrometry Letters
• /
• v.10 no.1
• /
• pp.1-10
• /
• 2019

Amphetamine-type stimulants (ATS) are a group of ${\beta}$-phenethylamine derivatives that produce central nervous system stimulants effects. The representative ATS are methamphetamine and 3, 4-methylenedioxymethamphetamine (MDMA), and abuse of ATS has become a global problem. Methamphetamine is abused in North America and Asia, while amphetamine and 3, 4-methyle nedioxym ethamphetamine (Ecstasy) are abused in Europe and Australia. Methamphetamine is also the most abused drug in Korea. In addition to the conventional ATS, new psychoactive substances (NPS) including phenethylamines and synthetic cathinones, which have similar effects and chemical structure to ATS, continue to spread to the global market since 2009, and more than 739 NPS have been identified. For the analysis of ATS, two tests that have different theoretical principles have to be conducted, and screening tests by immunoassay and confirmatory tests using GC/MS or LC/MS are the global standard methods. As most ATS have a chiral center, enantiomer separation is an important point in forensic analysis, and it can be conducted using chiral derivatization reagents or chiral columns. In order to respond to the growing drug crime, it is necessary to develop a fast and efficient analytical method.

• Analytical Science and Technology
• /
• v.33 no.1
• /
• pp.23-32
• /
• 2020

Methamphetamine (MA) is the most common and available drug of abuse in Korea and its primary metabolite is amphetamine (AP). Detection of AP derivatives, such as MA, AP, phentermine (PT), MDA, MDMA, and MDEA by the use of immunoassay screening is not reliable and accurate due to cross-reactivity and insufficient specificity/sensitivity. Therefore, the analytical process accepted by most urine drug-testing programs employs the two-step method with an initial screening test followed by a more specific confirmatory test if the specimen screens positive. In this study, a gas chromatography-mass spectrometric (GC-MS) method was developed and validated for confirmation of MA and AP in human urine. Urine sample (500 µL) was added with N-isopropylbenzylamine as internal standard and ethyl chloroformate as a derivatization reagent, and then extracted with 200 µL of ethyl acetate. Extracted samples were analysed with GC-MS in the SIM/ Scan mode, which were screened by Cobas c311 analyzer (Roche/Hitachi) to evaluate the efficiency as well as the compatibility of the GC-MS method. Qualitative method validation requirements for selectivity, limit of detection (LOD), precision, accuracy, and specificity/sensitivity were examined. These parameters were estimated on the basis of the most intense and characteristic ions in mass spectra of target compounds. Precision and accuracy were less than 5.2 % (RSD) and ±14.0 % (bias), respectively. The LODs were 3 ng/mL for MA and 1.5 ng/mL for AP. At the screening immunoassay had a sensitivity of 100% and a specificity of 95.1 % versus GC-MS for confirmatory testing. The applicability of the method was tested by the analysis of spiked urine and abusers' urine samples.

• YAKHAK HOEJI
• /
• v.55 no.2
• /
• pp.145-153
• /
• 2011

A simultaneous detection and quantification method for determining the Phenylalkylamine derivatives, such as methamphetamine (MA), amphetamine (AM), 3,4-methylenedioxymethamphetamine (MDMA), 3,4-methylenedioxyamphetamine (MDA), ketamine (KT), norketamine (NKT), phentermine (PT), fenfluramine (FFA) and phenmetrazine (PM), in oral fluid was developed and validated according to international guidelines. The validated method was applied to actual oral fluid samples collected from drug abuse suspects. The recovery of phenylalkylamines from oral fluid collection devices was also assessed. Oral fluid specimens from 20 drug abuse suspects submitted by the police were collected using Salivette$^{TM}$, Quantisal$^{TM}$ or direct expectoration. The samples were screened using a biochip array analyzer. For confirmation, the samples were analyzed by GC-MS in selected-ion monitoring (SIM) mode after extraction using automated SPE with a mixed-mode cation exchange cartridge and derivatization with trifluoroacetic anhydride (TFAA). The results from the immunoassay were consistent with those from GC-MS. All the oral fluid samples gave positive results for MA, AM, PT and/or PM. The detection of phenylalkylamines in oral fluid can provide a better indication of recent use than urine or hair. Therefore, the oral fluid specimen was useful for demonstrating phenylalkylamines abuse in the driving under the influence of drug (DUID) as an alternative specimen for urine.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.17 no.10
• /
• pp.2768-2787
• /
• 2023

As an important research direction of the application of computer science in the medical field, the automatic generation technology of radiology report has attracted wide attention in the academic community. Because the proportion of normal regions in radiology images is much larger than that of abnormal regions, words describing diseases are often masked by other words, resulting in significant feature loss during the calculation process, which affects the quality of generated reports. In addition, the huge difference between visual features and semantic features causes traditional multi-modal fusion method to fail to generate long narrative structures consisting of multiple sentences, which are required for medical reports. To address these challenges, we propose a multi-feature optimization Transformer (MFOT) for generating radiology reports. In detail, a multi-dimensional mapping attention (MDMA) module is designed to encode the visual grid features from different dimensions to reduce the loss of primary features in the encoding process; a feature pre-fusion (FP) module is constructed to enhance the interaction ability between multi-modal features, so as to generate a reasonably structured radiology report; a detail enhanced attention (DEA) module is proposed to enhance the extraction and utilization of key features and reduce the loss of key features. In conclusion, we evaluate the performance of our proposed model against prevailing mainstream models by utilizing widely-recognized radiology report datasets, namely IU X-Ray and MIMIC-CXR. The experimental outcomes demonstrate that our model achieves SOTA performance on both datasets, compared with the base model, the average improvement of six key indicators is 19.9% and 18.0% respectively. These findings substantiate the efficacy of our model in the domain of automated radiology report generation.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.32 no.2
• /
• pp.223-229
• /
• 2003

An amine rich diet with nitrate was incubated in simulated saliva, gastric juice, kale juice, and its ascorbate and methanol soluble portions (5, 10, 15 and 30 mL) for 1 hr at 37$^{\circ}C$ and N-nitrosodimethylamine (NDMA) was detected in the digestion sample, Kale juice and its ascorbate and methanol soluble portions at 30mL inhibited NDMA formation by 60.1$\pm$4.4%, 49.3$\pm$1.2% and 50.1$\pm$2.0%, respectively. The methanol soluble portion was further fractionated by preparative-LC (prep-LC). Nitrite-scavenging effects of 7 methanol soluble portion (Kl, K2, K3, K4, K5, K6 and K7) in kale juice were 2.0 ~56.2%. Among seven fractions, K3, K4, K5 and K7 exhibited weakly on nitrite scavenging effect. Fraction Kl and K2 inhibited NDMA formation by 71.0 and 65.5%, respectively. Fraction Kl and K2 was further separated by prep-LC into 6 subfractions (Kla, Klb, Klc, K2a, K2b and 2nc). Those subfractions inhibited NDMA formation by 40.9 ~80.4%. The K2a subfraction was screened by MS, $^1$H-NMR, $^{13}$ C-NMR and DEPT spectrum.