• Journal of Korean Medical Science
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• v.33 no.52
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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.

• Analytical Science and Technology
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• v.36 no.3
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• pp.121-127
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• 2023

The detection of blood at a crime scene is an important process for identification and case reconstruction. However, blood may be difficult to observe with the naked eye on dark or multi-colored surfaces. Acidic hydrogen peroxide (AHP) is a recently reported blood enhancement reagent that can enhance blood with high sensitivity by increasing the exposure time of the camera. However, it has never been compared to previously known techniques on dark or multi-colored surfaces. For this purpose, the method of observation/photographing (UV and IR photography), alginate casting, leuco rhodamine 6G (LR6G), and AHP were applied to bloody impression on dark or multi-colored surfaces and the results were compared. As a result, blood treated with AHP had a higher contrast to the surfaces than UV and IR photography, and it was applicable on all surfaces, opposed to alginate casting. In addition, AHP successfully enhanced blood on dark or multi-colored surfaces, similar to LR6G.

• Analytical Science and Technology
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• v.11 no.2
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• pp.1013-1024
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• 1998

• Korean Journal of Pharmacognosy
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• v.52 no.2
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• pp.69-76
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• 2021

Cannabis sativa is an important industrial plant utilized to produce fiber, oil, and medicinal ingredients. A chemotype of cannabis is divided into "Drug type" with predominance of tetrahydrocannabinolic acid (THCA) and "Fiber type" with cannabidiolic acid (CBDA). To develop molecular markers for the discrimination of these two types, nucleotide sequences of THCA synthase and CBDA synthase as well as their pseudogenes were retrieved from the recently published cannabis genome in chromosome scale. Gene-specific SNPs were discovered by multiple alignment of these sequences, and 2 dominant marker sets from each gene were designed for selective amplification. Our markers successfully identified "Drug type" and "Fiber type" cannabis plants as well as forensic samples including processed materials. Our molecular markers will provide a fast and efficient system for molecular-based identification of the cannabis plant.

• Analytical Science and Technology
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• v.17 no.3
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• pp.271-277
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• 2004

The aim of this study was to investigate questioned documents written with blue or black ballpoint pen on paper by nondestructive technique. In this work, 21 blue and 22 black ballpoint pen inks which were purchased on different brands were analyzed by using Microspectrophotometry (MSP). The reflectance spectra were obtained from these ink samples and their shapes and the wavelength of the maximum intensity were compared. In the blue and black ballpoint pen inks, the discriminating powers (DP) were 0.85 and 0.61, respectively. The changes of the reflectance intensity at their wavelength of maximum intensity and their shapes appeared according to the exposure time to sunshine in a laboratory, especially in the blue ballpoint pen inks. Therefore it is possible to distinguish ink entries on the same paper with the relative age in case of questioned letters written with blue ballpoint pen.

• Proceedings of the Zoological Society Korea Conference
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• 2003.08a
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• pp.205.3-205
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• 2003

No Abstract, See Full Text

• Analytical Science and Technology
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• v.17 no.4
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• pp.315-321
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• 2004

The aim of this study was to investigate the evidential value of blue and black ballpoint pens on paper by nondestructive techniques. In this work, 21 blue and 22 black ballpoint pens which were purchased on different brands were analyzed by Raman Spectroscopy and Video Spectral Comparator (VSC). Surface-Enhanced Resonance Raman Spectroscopy (SERRS) with excitation at 685 nm and VSC with several spot light filters were used for the discrimination of ballpoint pen inks. In the SERR spectra, the ballpoint pen inks on paper could be shown sharp spectral bands and distinguished by their band shapes and relative intensities. In the blue and black ballpoint pen inks, the discriminating powers (DP) by SERRS were 0.85 and 0.67 and the DP by VSC were 0.88 and 0.90, respectively. The DP by combined sequence of techniques was all 0.97 in both black and blue ballpoint pen inks.

• Journal of Preventive Medicine and Public Health
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• v.54 no.3
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• pp.218-219
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• 2021

The identification of human remains can be performed visually through families and next-of-kin, but it is not advisable to rely only on visual recognition; instead, it is preferable to conduct a forensic comparison of antemortem and postmortem data for primary identifiers (fingerprints, DNA, and dental data). A dental autopsy is particularly valuable in the identification process of skeletonized, carbonized, saponified, and fragmented human remains. The principal challenge in the identification process is the search and collection of antemortem data. To this end, all dental information held on a missing person can represent a precious source of individualizing information that families should share with the police or investigating agencies after reporting a disappearance.

• Analytical Science and Technology
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• v.19 no.1
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• pp.103-106
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• 2006

A 35-year-old Perubian who suffered from grand mal seizures died in the aircraft on his way from the United States to Hongkong via Incheon international airport of Korea. While performing the autopsy, 115 packs made with double layer of transparent film and black plastic bag containing cocaine were found in the ileum and large intestine. Among of them, 3 packs were ruptured. To determine the concentration of cocaine and its metabolites, blood, urine, bile, liver, spleen, heart, kidney, brain and gastric contents were taken and toxicological analysis was performed. Gas chromatography/mass spectrometry (GC/MS) following liquid-phase extraction using chloroform:isopropanol (=9:1) and derivatization with bis(trimethylsilyl)-trifluoroacetamide (contains 1% trimethylchlorosilane) was performed. High levels of cocaine, benzoylecgonine (BE) and ecgonine methylester (EME) were found in the postmortem blood (0.96, 3.09 and $5.59{\mu}g/mL$) and urine (32.85, 145.35 and $53.17{\mu}g/mL$), respectively. Cocaine and its metabolites were also detected in all other biological specimen.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.463-466
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• 2012

Smartphones along with the development of crime evidence has been using smartphones. Phone's internal storage medium can be used as evidence in the case of images, video, phone, GPS information, there are Internet access and other data records. Therefore, these data to collect evidence of a systematic procedure for collecting and analyzing evidence is needed. In this paper, the target mobile phone forensics forensic evidence collection, evidence analysis, and reporting results to the procedures and how to draw. Through this paper, phone forensics and will serve as a basis for the investigation.