• BMB Reports
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• v.56 no.12
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• pp.657-662
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• 2023

Neurodegenerative diseases are characterized by distinct protein aggregates, such as those of α-synuclein and tau. Lysosomal defect is a key contributor to the accumulation and propagation of aberrant protein aggregates in these diseases. The discoveries of common proteinopathies in multiple forms of lysosomal storage diseases (LSDs) and the identification of some LSD genes as susceptible genes for those proteinopathies suggest causative links between LSDs and the proteinopathies. The present study hypothesized that defects in lysosomal genes will differentially affect the propagation of α-synuclein and tau proteins, thereby determining the progression of a specific proteinopathy. We established an imaging-based high-contents screening (HCS) system in Caenorhabditis elegans (C. elegans) model, by which the propagation of α-synuclein or tau is measured by fluorescence intensity. Using this system, we performed RNA interference (RNAi) screening to induce a wide range of lysosomal malfunction through knock down of 79 LSD genes, and to obtain the candidate genes with significant change in protein propagation. While some LSD genes commonly affected both α-synuclein and tau propagation, our study identified the distinct sets of LSD genes that differentially regulate the propagation of either α-synuclein or tau. The specificity and efficacy of these LSD genes were retained in the disease-related phenotypes, such as pharyngeal pumping behavior and life span. This study suggests that distinct lysosomal genes differentially regulate the propagation of α-synuclein and tau, and offer a steppingstone to understanding disease specificity.

• The Transactions of the Korea Information Processing Society
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• v.13 no.3
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• pp.130-139
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• 2024

Artificial intelligence models are being used to detect facility anomalies using physics data such as vibration, current, and temperature for predictive maintenance in the manufacturing industry. Since the types of facility anomalies, such as facility defects and failures, anomaly detection methods using autoencoder-based unsupervised learning models have been mainly applied. Normal or abnormal facility conditions can be effectively classified using the reconstruction error of the autoencoder, but there is a limit to identifying facility anomalies specifically. When facility anomalies such as unbalance, misalignment, and looseness occur, the facility vibration frequency shows a pattern different from the normal state in a specific frequency range. This paper presents an N-segmentation anomaly detection method that performs anomaly detection by dividing the entire vibration frequency range into N regions. Experiments on nine kinds of anomaly data with different frequencies and amplitudes using vibration data from a compressor showed better performance when N-segmentation was applied. The proposed method helps materialize them after detecting facility anomalies.

• Journal of Life Science
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• v.14 no.1
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• pp.21-25
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• 2004

To identify genes involved in the decolorization of both crystal violet and malachite green, we isolated random mutants generated by transposon insertion in triphenylmethane-decolorizing bacterium, Citrobacter sp. The resulting mutant bank yielded 14 mutants with complete defect in color removal capability of both crystal violet and malachite green. Southern hybridization with a Tn5 fragment as a probe showed a single hybridized band in 5 mutants and these mutants appeared to have insertions at different sites of the chromosome. Tn5-inserted genes were isolated and the DNA sequence flanking Tn5 was determined. From comparison with a sequence database, putative protein products encoded by cmg genes were identified as follows. cmg 2 is MaIC protein in maltose transport system; cmg 6 is transcriptional regulator (LysR-type): cmg 12 is a putative oxidoreductase. The sequences deduced from two cmg genes, cmg 8 and cmg 11, showed no significant similarity to any protein with a known function. Therefore, these results indicate that these two cmg genes encode unidentified proteins responsible for decolorization of both crystal violet and malachite green.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.1
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• pp.40-45
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• 2015

Electrode systems: a protrusion on conductor (POC), a protrusion on enclosure (POE), a crack in epoxy plate and a free particle (FP) were fabricated to simulate insulation defects in a gas insulated switchgear (GIS). $SF_6$ gas was filled in the electrode systems by 3 bar and/or 5 bar, respectively. Partial discharge (PD) pulses were detected through a $50{\Omega}$ non-inductive resistor. A calibration test was carried out according to IEC 60270, and the sensitivity was 0.25 pC/mV. PD pulses were distributed in the phase of $50^{\circ}{\sim}135^{\circ}$ and over 95% of them existed in the phase of $55^{\circ}{\sim}120^{\circ}$ for the POC. PD pulses were distributed in the phase of $230^{\circ}{\sim}310^{\circ}$ and over 90% of them existed in phase of $220^{\circ}{\sim}300^{\circ}$ for the POE. PD pulses occurred in the phase of $40^{\circ}{\sim}60^{\circ}$ and $220^{\circ}{\sim}300^{\circ}$ for the crack, and pulse counts were 25% higher in negative polarity than in positive polarity. PD pulses were distributed in every phase unlike to other three electrode systems and the peak magnitude was measured at $118^{\circ}$ and $260^{\circ}$ for the FP. As described above, PD pulses were observed in positive polarity for the POC, in negative one for the POE, in both one for the crack and the FP. In conclusion, it is expected that the identification rate of defect type can be improved by considering the polarity ratio of PD pulses on the PRPDA method.

• Journal of the Korean Vacuum Society
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• v.17 no.4
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• pp.311-316
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• 2008

Since the presence of the chemical impurities and defect at surfaces and interfaces greatly influence the properties of various semiconductor devices, an unambiguous chemical characterization of the metal and semiconductor surfaces become more important in the view of the miniaturization of the devices toward nano scale. Among the various conventional surface characterization tools, Electron-induced Auger Electron Spectroscopy (EAES), X-ray Photoelectron Spectroscopy (XPS) and Secondary Electron Ion Mass Spectroscopy (SIMS) are being used for the identification of the surface chemical impurities. Recently, a novel surface characterizaion technique, Positron-annihilation induced Auger Electron Spectroscopy (PAES) is introduced to provide a unique method for the analysis of the elemental composition of the top-most atomic layer. In PAES, monoenergetic positron of a few eV are implanted to the surface under study and these positrons become thermalized near the surface. A fraction of the thermalized positron trapped at the surface state annihilate with the neighboring core-level electrons, creating core-hole excitations, which initiate the Auger process with the emission of Auger electrons almost simultaneously with the emission of annihilating gamma-rays. The energy of electrons is generally determined by employing ExB energy selector, which shows a poor resolution of $6{\sim}10eV$. In this paper, time-of-flight system is employed to measure the electrons energy with an enhanced energy resolution. The experimental result is compared with simulation results in the case of both linear (with retarding tube) and reflected TOF systems.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.167-167
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• 2010

반도체는 도핑하지 않으면 대부분 n형을 나타내는 것에 반하여 GaSb는 p형을 보이는 반도체로서, 그 근원은 명확하게 규명되어 있지 않은 상태이다. GaSb의 p형 불순물인 Be은 Ga과 치환 ([$Be_{Ga}$])되므로, p형 전도의 근원으로 추정되는 잔존결함인 [$Ga_{Sb}$]와 그 복합체인 [$Ga_{Sb}-Sb_{Ga}$]와 높은 상관관계를 가질 것으로 예측된다. 본 연구에서는 Be을 도핑한 GaSb:Be 에피층을 MBE 방법으로 성장하여, PL 스펙트럼과 Hall 효과 분석을 통하여 p형 전도의 근원을 조사하였다. 도핑하지 않은 u-GaSb는 DA (deep acceptor)와 함께 A 준위를 나타낸 반면, p-GaSb:Be의 PL 스펙트럼은 Be 도핑농도가 증가함에 따라 FWHM가 줄어들면서 점차 높은 에너지 영역으로 변위하지만 농도가 가장 높은 시료에서는 PL의 FWHM가 증가하면서 에너지는 감소함이 관측되었는데, 이것은 A 피크와 Sb 관련 피크가 경쟁적으로 중첩되어 나타난 현상으로 분석된다. Hall 효과 결과는 유효 전하밀도의 증가에 따라 이동도는 감소하는 전형적인 의존성을 나타내었으며, u-GaSb의 Hall 이동도가 p-GaSb:Be의 값보다 작은 것은 u-GaSb에 잔존하는 DA에 의한 산란 때문으로 해석된다. Gaussian 형태로 분해하여 얻은 A ([$Ga_{Sb}$])와 DA ([$Ga_{Sb}-Sb_{Ga}$]) 및 Be 관련 피크로부터 특정 도핑농도 ($1.2{\times}10^{17}cm^{-3}$)의 시료를 제외한 모든 p-GaSb:Be에는 A 피크가 중첩되고 A와 Be 준위 중간에 Be과의 복합체인 중간상태(intermediate state)인 [$Be^*$]가 존재함이 관측되었는데, 특정 도핑농도에서는 [$Be_{Ga}$]이 우세하지만 더 이상 농도가 증가하면 [$Be_{Ga}$] 준위의 강도는 오히려 감소함을 관측할 수 있었다. 이것은 적정 이상의 Be을 도핑할 경우, A ([$Be_{Ga}$])와 $Be^*([Be_{Ga}-Ga_Sb}])$가 형성 ($A[Ga_{Sb}]+Be{\rightarrow}Be^*[Be_{Ga}-Ga_{Sb}]+[Be_{Ga}]$)됨을 보여 주는 중요한 결과인 것으로 분석된다. A, [Be], [$Be^*$] PL 피크 에너지는 각각 779, 787, 794 meV (오차범위 ${\pm}3\;meV$)이고, [$Be_{Ga}$]의 활성화 에너지는 ($23{\pm}3\;meV$) (20 K)임을 밝혔다.

• Microbiology and Biotechnology Letters
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• v.49 no.3
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• pp.458-465
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• 2021

Tubulysins are a group of bioactive secondary metabolites from myxobacteria exhibiting strong anticancer activity against various cancer cell lines. In this study, we describe the identification of putative tubulysin biosynthetic gene clusters (tubA~tubF) in the genome sequences of two tubulysin-producing myxobacterial strains, Archangium gephyra MEHO_002 and MEHO_004. The inactivation of the putative tubulysin biosynthetic genes resulted in a tubulysin-production defect. The DNA sequences of the A. gephyra MEHO_002 and MEHO_004 tubulysin biosynthetic genes were 97% identical, and the amino acid sequences of the encoded proteins shared a similarity of 97-100%. The nucleotide sequences of the tubulysin biosynthetic gene clusters in MEHO_002 and MEHO_004 were 86% identical to that in Cystobacter sp. SBCb004 known as a tubulysin-producing myxobacterium, and the organization of the clusters was identical except for the lack of a tubZ gene in the clusters in MEHO_002 and MEHO_004. The amino acid sequences of the proteins encoded by each gene were 88-97% similar to those encoded by SBCb004, and the domain compositions of the proteins were also identical.

• Childhood Kidney Diseases
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• v.3 no.2
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• pp.209-216
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• 1999

Purpose : Nephrogenic diabetes insipidus (NDI) is a rare X-linked disorder associated with renal tubule resistance to arginine vasopressin (AVP). The hypothesis that the defect underlying NDI might be a dysfunctional renal AVPR2 has recently been proven by the identification of mutations in the AVPR2 gene in NDT patients. To investigate the association of mutations in th AVPR2 gene with NDI, we analyzed the AVPR2 gene located on the X chromosome. Methods : We have analyzed the AVPR2 gene in a kindred with X-linked NDI. The proband and proband's mother were analyzed by polymerase chain reaction-single strand conformational polymorphism(PCR-SSCP) and DNA sequencing of the AVPR2 gene. We also have used restriction enzyme analysis of genomic PCR product to evaluate the AVPR2 gene. Results : C to T transition at codon 202, predictive of an exchange of tryptophan 202 by cysteine(R202C) in the third extracellular domain was identified. This mutation causes a loss of Hae III site within the gene. Conclusion : We found a R202C missense mutation in the AVPR2 gene causing X-linked NDI, and now direct mutational analysis is available for carrier screening and early diagnosis.

• Journal of Science and Technology Studies
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• v.5 no.1 s.9
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• pp.55-92
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• 2005

The factors contributing to the formation of an important scientific concept in South Korea and its circulation in the society are the scientific knowledge that had been already formed, matured, and established in the U.S.A, Europe and Japan and has been introduced into Korea, and the institutions that have been formed during the recent modernization in South Korea. The concept of 'genetic information' cannot be an exception in this context. The concept of genetic information is the one that has been extended and intensified by the genomics and bioinformatics formed and matured through the Human Genome Projects from the former concept of inheritance or heredity within the framework of classical and molecular genetics. The purpose of this study was to find out 'how the production structure of genetic information in South Korea has been formed', under the perspective of the conceptual, epistemic, and institutional holisticity or integratedness in the concept and knowledge production structure idealized in Western advanced nations. The discourse of genetic engineering popular in the mid 1980's in South Korea has catalyzed the development of molecular biology. However, the institutional balance that had been established for the biochemistry departments in Natural Science College and Medical College was not formed between the genetic engineering and genetics departments in South Korea. Therefore, they were unable to achieve the more integrative and macro-level disciplinary impact on life sciences, largely due to institutional lack of the capable (human) genetics departments in some leading Korean colleges of Medicine. In genomics, the cutting-edge reprogramming and restructuring of the traditional genetics in the West, South Korea has not invested, even meagerly, in the infrastructure, fund, and research and development (R & D) for the Basic or First Phase of the research trajectory in the Human Genome Project. Without a minimal Basic Phase, the genomics research and development in Korea has been running more or less for the Advanced or Second Phase. Bioinformatics has started developing in Korea under a narrow perspective which regards it as a mere sub-discipline of information technology (IT). Having developed itself in parallel with genomics, bioinformatics contains its own unique logics and contents that can be both directly and indirectly connected to the information science and technology. As a result, bioinformatics reveals a defect in respect of being synergistically integrated into genetics and life sciences in Korea. Owing to the structural problem in the production, genetic information appears to be produced in a fragmented pattern in the Korean society since its fundamental base is weak and thin. A good example of the conceptual and institutional fragmentedness is that 'the genetics of individual identification' is not a normal integrated part of the Korean genetics, but a scientific practice exercised in the departments of legal medicine in a few Medical Colleges. And the environment contributing to the production structure of genetic information in South Korea today comprises 'sangmyung gonghak'(or life engineering) discourse and non-governmental organization movement.