• Mass Spectrometry Letters
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• 제7권2호
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• pp.31-40
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• 2016

The analysis of nuclear materials and environmental samples is an important issue in nuclear safeguards and nuclear forensics. An analysis technique for safeguard samples has been developed for the detection of undeclared nuclear activities and verification of declared nuclear activities, while nuclear forensics has been developed to trace the origins and intended use of illicitly trafficked nuclear or radioactive materials. In these two analytical techniques, mass spectrometry has played an important role in determining the isotope ratio of various nuclides, contents of trace elements, and production dates. These two techniques typically use similar analytical instruments, but the analytical procedure and the interpretation of analytical results differ depending on the analytical purpose. The isotopic ratio of the samples is considered the most important result in an environmental sample analysis, while age dating and impurity analysis may also be important for nuclear forensics. In this review, important aspects of these techniques are compared and the role of mass spectrometry, along with recent progress in related technologies, are discussed.

• Bulletin of the Korean Chemical Society
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• 제34권8호
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• pp.2413-2418
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• 2013

Forensic and legal medicine require reliable data to indicate excessive alcohol consumption. Ethanol is oxidatively metabolized to acetate by alcohol dehydrogenase and non-oxidatively metabolized to ethyl glucuronide (EtG), ethyl sulfate (EtS), phosphatidylethanol, or fatty acid ethyl esters (FAEE). Oxidative metabolism is too rapid to provide biomarkers for the detection of ethanol ingestion. However, the non-oxidative metabolite EtG is a useful biomarker because it is stable, non-volatile, water soluble, highly sensitive, and is detected in body fluid, hair, and tissues. EtG analysis methods such as mass spectroscopy, chromatography, or enzyme-linked immunosorbent assay techniques are currently in use. We suggest that nuclear magnetic resonance (NMR) spectroscopy could be used to monitor ethanol intake. As with current conventional methods, NMR spectroscopy doesn't require complicated pretreatments or sample separation. This method has the advantages of short acquisition time, simple sample preparation, reproducibility, and accuracy. In addition, all proton-containing compounds can be detected. In this study, we performed $^1H$ NMR analyses of urine to monitor the ethanol and EtG. Urinary samples were collected over time from 5 male volunteers. We confirmed that ethanol and EtG signals could be detected with NMR spectroscopy. Ethanol signals increased immediately upon alcohol intake, but decreased sharply over time. In contrast, EtG signal increased and reached a maximum about 9 h later, after which the EtG signal decreased gradually and remained detectable after 20-25 h. Based on these results, we suggest that $^1H$ NMR spectroscopy may be used to identify ethanol non-oxidative metabolites without the need for sample pretreatment.

• Journal of Korean Medical Science
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• 제33권52호
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• pp.337.1-337.14
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• 2018

Background: Mitochondrial heteroplasmy, the co-existence of different mitochondrial polymorphisms within an individual, has various forensic and clinical implications. But there is still no guideline on the application of massively parallel sequencing (MPS) in heteroplasmy detection. We present here some critical issues that should be considered in heteroplasmy studies using MPS. Methods: Among five samples with known innate heteroplasmies, two pairs of mixture were generated for artificial heteroplasmies with target minor allele frequencies (MAFs) ranging from 50% to 1%. Each sample was amplified by two-amplicon method and sequenced by Ion Torrent system. The outcomes of two different analysis tools, Torrent Suite Variant Caller (TVC) and mtDNA-Server (mDS), were compared. Results: All the innate heteroplasmies were detected correctly by both analysis tools. Average MAFs of artificial heteroplasmies correlated well to the target values. The detection rates were almost 90% for high-level heteroplasmies, but decreased for low-level heteroplasmies. TVC generally showed lower detection rates than mDS, which seems to be due to their own computation algorithms which drop out some reference-dominant heteroplasmies. Meanwhile, mDS reported several unintended low-level heteroplasmies which were suggested as nuclear mitochondrial DNA sequences. The average coverage depth of each sample placed on the same chip showed considerable variation. The increase of coverage depth had no effect on the detection rates. Conclusion: In addition to the general accuracy of the MPS application on detecting heteroplasmy, our study indicates that the understanding of the nature of mitochondrial DNA and analysis algorithm would be crucial for appropriate interpretation of MPS results.

• Journal of Veterinary Science
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• 제25권3호
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• pp.24.1-24.9
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• 2024

Importance: In veterinary forensic science, accurately determining the postmortem interval (PMI) is crucial for identifying the causes of animal deaths. Autolysis, a significant postmortem process, influences PMI estimation, but its relationship with humidity is not well understood. Objective: This study aimed to improve the accuracy of PMI estimates in veterinary forensic cases by looking into how different humidity levels affect autolysis in different organs of rats. Methods: The study involved 38 male rats, examining histopathological changes in their heart, liver, and pancreas. These organs were subjected to controlled humidity levels (20%, 55%, and 80%) at a constant 22℃. Tissue samples were collected at several intervals (0 h, 12 h, 24 h, 3 days, and 8 days) for comprehensive analysis. Results: Distinct autolytic characteristics in animal organs emerged under varying humidity conditions. The low-humidity environment rapidly activated autolysis more than the high-humidity environment. In addition, it was found that lower humidity caused nuclear pyknosis, cytoplasmic disintegration, and myofiber interruption. The liver, in particular, showed portal triad aggregation and hepatocyte individuation. The pancreas experienced cell fragmentation and an enlarged intracellular space. High humidity also caused the loss of striations in cardiac tissues, and the liver showed vacuolation. Under these conditions, the pancreas changed eosinophilic secretory granules. Conclusions and Relevance: The study successfully established a clear connection between the autolytic process in PMIs and relative humidity. These findings are significant for developing a more accurate and predictable method for PMI estimation in the field of veterinary forensic science.

• 방사성폐기물학회지
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• 제20권2호
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• pp.171-183
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• 2022

The parent and daughter nuclides in a radioactive decay chain arrive at secular equilibrium once they have a large half-life difference. The characteristics of this equilibrium state can be used to estimate the production time of nuclear materials. In this study, a mathematical model and algorithm that can be applied to radio-chronometry using the radioactive equilibrium relationship were investigated, reviewed, and implemented. A Bateman equation that can analyze the decay of radioactive materials over time was used for the mathematical model. To obtain a differential-based solution of the Bateman equation, an algebraic numerical solution approach and two different matrix exponential functions (Moral and Levy) were implemented. The obtained result was compared with those of commonly used algorithms, such as the Chebyshev rational approximation method and WISE Uranium. The experimental analysis confirmed the similarity of the results. However, the Moral method led to an increasing calculation uncertainty once there was a branching decay, so this aspect must be improved. The time period corresponding to the production of nuclear materials or nuclear activity can be estimated using the proposed algorithm when uranium or its daughter nuclides are included in the target materials for nuclear forensics.

• Nuclear Engineering and Technology
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• 제49권4호
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• pp.787-791
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• 2017

Americium-beryllium (Am-Be; n, ${\gamma}$) is a neutron emitting source used in various research fields such as chemistry, physics, geology, archaeology, medicine, and environmental monitoring, as well as in the forensic sciences. It is a mobile source of neutron activity (20 Ci), yielding a small thermal neutron flux that is water moderated. The aim of this study is to develop a model to increase the neutron thermal flux of a source such as Am-Be. This study achieved multiple advantageous results: primarily, it will help us perform neutron activation analysis. Next, it will give us the opportunity to produce radio-elements with short half-lives. Am-Be single and multisource (5 sources) experiments were performed within an irradiation facility with a paraffin moderator. The resulting models mainly increase the thermal neutron flux compared to the traditional method with water moderator.

• Journal of Korean Neurosurgical Society
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• 제59권6호
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• pp.544-550
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• 2016

Objective : Cerebral endothelial cells have unique biological features and are fascinating candidate cells for stroke therapy. Methods : In order to understand the molecular mechanisms of human cerebral endothelial cell (hCMEC/D3) transplantation in a rat stroke model, we performed proteomic analysis using 2-dimensional electrophoresis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Protein expression was confirmed by quantitative real-time PCR and Western blot. Results : Several protein spots were identified by gel electrophoresis in the sham, cerebral ischemia (CI), and CI with hCMEC/D3 treatment cerebral ischemia with cell transplantation (CT) groups, and we identified 14 differentially expressed proteins in the CT group. Proteins involved in mitochondrial dysfunction (paraplegin matrix AAA peptidase subunit, SPG7), neuroinflammation (peroxiredoxin 6, PRDX6), and neuronal death (zinc finger protein 90, ZFP90) were markedly reduced in the CT group compared with the CI group. The expression of chloride intracellular channel 4 proteins involved in post-ischemic vasculogenesis was significantly decreased in the CI group but comparable to sham in the CT group. Conclusion : These results contribute to our understanding of the early phase processes that follow cerebral endothelial cell treatment in CI. Moreover, some of the identified proteins may present promising new targets for stroke therapy.

• 식물분류학회지
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• 제48권4호
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• pp.289-300
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• 2018

Coreanomecon is a monotypic and endemic genus in Korea, distributed mainly in the southern regions. Coreanomecon is morphologically similar to Hylomecon by producing red latex, easily distinguished from Chelidonium, which produces yellow latex. Coreanomecon were merged into Hylomecon or Chelidonium depending on the authors. To understand the phylogenetic relationship of Coreanomecon, DNA sequences of chloroplast rbcL and matK and nuclear Internal Transcribed Spacer (ITS) regions were determined from the species of Papaveroideae (Papaveraceae) in Korea and analyzed with the Maximum Parsimony and Bayesian methods. Phylogenetic analyses of Papaveroideae suggest that Coreanomecon is sister to the clade of Chelidonium and Stylophorum in the ITS data and that it is sister to Hylomecon in the chloroplast (cpDNA) data. A constraining analysis using the Shimodaira-Hasegawa test (S-H test) suggested that the ITS data do not reject the sister relationship of Coreanomecon and Hylomecon. The S-H test also suggested that the cpDNA data is compatible with the placement of Coreanomecon as a sister to the clade of Chelidonium and Stylophorum. Although the conflicting phylogenetic results may stem from insufficient phylogenetic signals, they may also be associated with hybridization between Hylomecon and an ancestor of Stylophorum and Chelidonium. The results of this study suggest that Coreanomecon is a distinct lineage as an endemic genus, supporting the morphological data.

• Asian Pacific Journal of Cancer Prevention
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• 제15권2호
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• pp.803-805
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• 2014

The IL-16 rs4778889 T/C polymorphism is associated with cancer risk. However, the results are conflicting. We performed this meta-analysis to derive a more precise estimation of the relationship. A comprehensive literature search was performed using PubMed, Embase and Web of Science databases. Odds ratio (OR) and 95% confidence interval (CI) were used to assess the strength of association. A total of 6 studies including 1,603 cases and 2,342 controls were identified. With all studies involved, results showed no statistically significant association between IL-16 rs4778889 T/C polymorphism and cancer risk (CC vs. CT+TT: OR=0.74, 95%CI:0.55-1.02, $P_h=0.15$; CC+CT vs. TT: OR=0.89, 95%CI: 0.72-1.10, $P_h=0.03$; CC vs. TT: OR=0.73, 95%CI: 0.53-1.00, $P_h=0.08$; CT vs. TT: OR=0.91, 95%CI: 0.79-1.05, $P_h=0.08$; C vs. T: OR=0.89, 95%CI: 0.74-1.07, $P_h=0.02$). In addition, the results were not changed when studies were stratified by cancer type. However, to verify our findings, it is essential to perform more well-designed studies with larger sample sizes in the future.

• Journal of Oral Medicine and Pain
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• 제33권1호
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• pp.59-66
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• 2008

사람 Y염색체상에 존재하는 RPS4Y(Ribosomal Protein S4Y) 유전자는 성별감정시 유용한 유전자로 규명되어 유전질환의 조기 발견이나 예방 및 태아의 성별판정 등에 응용되고 있다. 신원이 불분명한 사체에서 성별감정시, 기존의 성별감정에 이용되고 있는 다른 유전자와 함께 RPS4Y 유전자를 검색함으로써 성별감정의 신뢰도를 높힐 수 있을 것으로 사료된다. 또한 사체의 손상이 심할 때 유전자를 이용한 개인식별은 제한을 받게 된다. 이때 치아는 인체의 기관 중 가장 견고한 구조로 구성되어 있어 외부 환경에 대한 물리적, 화학적 저항성이 높아 법의치과학적 개인식별에 널리 이용되므로, 본 연구에서는 사람 치아에서 중합효소연쇄반응법을 이용한 RPS4Y유전자를 검출하여 법의학적 성별감정에 응용하고자 하였다. 남녀 각각 10개의 치아에서 치수와 상아질을 분리한 후 DNA를 추출하여 중합효소연쇄반응을 시행하였다. RPS4Y 유전자를 검출한 결과, 남자에게서만 특이적으로 유전자가 검출되었으며, 이는 사람 치아에서 RPS4Y 유전자를 이용한 성별감정이 법의학적 개인식별의 성별감정 실무에 있어서 다른 유전자와 함께 유용하게 사용될 수 있을 것으로 사료된다.