디스크 부식에 의한 DTV 변화에 패드 마모가 미치는 영향 연구

이완규(Wankyu Lee),이강국(Kangkuk Lee),이인호(Inho Lee),현보원(Bowon Hyun),이성주(Seongju Lee) 한국자동차공학회 2019 한국자동차공학회 부문종합 학술대회 Vol.2019 No.5

The rust judder due to the disc corrosion have been known as a serious problem on automobile. Among various sources on the rust judder of vehicle, in this paper, the influence of brake pad wear particles was investigated using rig unit and vehicle with different friction materials. Results showed that the amount of wear particles critically affected to the change of DTV and to make a contact trace on the disc surface after corrosion test. In the case of pad material with the largest wear amount, the vibration of brake pedal and steering after corrosion was strongly felt during all braking stop in contrast with wear life enhanced pad material. Furthermore, the wear amount of disc was related with the linear change of DTV by corrosion. This study shows that the occurrence level of rust judder due to friction material can be predicted at the development stage of friction material.

Inflammasome-mediated inflammation by malassezia in human keratinocytes: a comparative analysis with different strains

( Hye Ree Park ),( Ji Hee Jung ),( Dong Geon Lee ),( Kyung Jae Lee ),( Jee Hye Oh ),( Eu Jin Lee ),( Song Hee Park ),( Yang Won Lee ),( Seongju Lee ),( Hoon Kang ),( Jung Eun Kim ) 대한피부과학회 2020 대한피부과학회 학술발표대회집 Vol.72 No.1

Background: Malassezia species are associated with several common dermatologic conditions including pityriasis versicolor, seborrheic dermatitis, folliculitis, and atopic dermatitis and dandruff. However, its causal role remains to be established. Objectives: We intended to explore the role of inflammasome activation in human keratinocytes in response to three different Malassezia species. Methods: We compared the different activation patterns of inflammasomes and the expression of proinflammatory cytokines and antimicrobial peptides by three different Malassezia species―M. restricta, M. globosa, and M. sympodialis―in human keratinocytes. Results: We found that different Malassezia species, especially M. restricta, and M. globosa could induce nucleotide-binding oligomerization domain, leucine-rich repeat and pyrin-domain-containing protein (NLRP)3- apoptosis-associated speck-like protein containing CARD (ASC) inflammasome activation and subsequent interleukin (IL)-1β secretion in human keratinocytes. Malassezia species variably induced thymic stromal lymphopoietin, β -defensin 2, and LL-37. IL-6 mRNA and IL-22 protein significantly increased in the M. sympodialis-treated group, and CCL17 and CCL27 mRNA were increased in response to M. globosa-treated keratinocytes. Conclusion: Our data show that various species of Malassezia promote variable inflammatory responses in keratinocytes by activating NLRP3 inflammasomes, pro-inflammatory cytokines and chemokines, and antimicrobial peptides.

CEP215 is involved in the dynein-dependent accumulation of pericentriolar matrix proteins for spindle pole formation.

Lee, Seongju,Rhee, Kunsoo Landes Bioscience 2010 Cell Cycle Vol.9 No.4

<P>CEP 215 is a human orthologue of Drosophila centrosomin which is a core centrosome component for the pericentriolar matrix protein recruitment. Recent investigations revealed that CEP 215 is required for centrosome cohesion, centrosomal attachment of the gamma-TuRC, and microtubule dynamics. However, it remains obscure how CEP 215 functions for recruitment of the centrosomal proteins during the centrosome cycle. Here, we investigated a role of CEP 215 during mitosis. Knockdown of CEP 215 resulted in characteristic mitotic phenotypes, including monopolar spindle formation, a decrease in distance between the spindle pole pair, and detachment of the centrosomes from the spindle poles. We noticed that CEP 215 is critical for centrosomal localization of dynein throughout the cell cycle. As a consequence, the selective centrosomal proteins were not recruited to the centrosome properly. Finally, the centrosomal localization of CEP 215 also depends on the dynein-dynactin complex. Based on the results, we propose that CEP 215 regulates a dynein-dependent transport of the pericentriolar matrix proteins during the centrosome maturation.</P>

The Assessment of Building Energy Savings Potential with Photochromic (PC) Window Based on Simulation Analysis

Seongju Lee,Younghun Seo,Jongho Yoon,Dongsu Kim 한국신재생에너지학회 2023 AFORE Vol.2023 No.11

239Pu and 99Tc Sorption to the Cementitious and Natural Rock Barriers: Effect of Organic Complexing Agents (EDTA and ISA)

Seongju Lee,Youngsu Lim,Bolam Kim,Dae Sung Lee 한국방사성폐기물학회 2022 한국방사성폐기물학회 학술논문요약집 Vol.20 No.2

Radionuclides can be leached into groundwater or soil over a long period of time due to unexpected situations even after being permanently disposed of in a repository. Therefore, it is necessary to investigate the mobility of radionuclides for the safety assessment of radioactive waste disposal. In this study, the effects of organic complexing agents such as ethylenediaminetetraacetic acid (EDTA) and isosaccharinic acid (ISA) on the sorption behavior of 239Pu and 99Tc over cementitious (concrete and grout) and natural rock samples (granite and sedimentary rock) were investigated in batch sorption experiments. For characterization of rock samples, XRD, XRF, FT-IR, FE-SEM, BET, and Zeta-potential analyses were performed. For the evaluation of mobility, the distribution coefficient (Kd) was selected and compared. The adsorption experiment was carried out at two pHs (7 and 13), a temperature of 20°C, and a range of organic complexing agents concentrations (10-7~10-2 M and 10- 5~10-2 M for 239Pu and 99Tc, respectively). The radionuclides concentrations in adsorption samples were analyzed using ICP-MS. The Kd values for 239Pu in all rock samples reduced significantly due to the presence of EDTA, even at low concentrations such as 10-5 M. In the case of ISA, the limiting noeffect concentration was much higher than that of EDTA. On the other hand, 99Tc showed relatively lower Kd values than 239Pu, and the sorption behavior of 99Tc was almost unaffected by the organic complexing agents for all rock samples. Therefore, it is possible to assume that the increased mobility of radionuclides, especially, 239Pu, in groundwater caused by the lowering of sorption at even low concentrations of organic complexing agents may result in the transport of radionuclides to the nearand far-field location of the repository.

Cellular senescence: a promising strategy for cancer therapy

( Seongju Lee ),( Jae-seon Lee ) 생화학분자생물학회 2019 BMB Reports Vol.52 No.1

Cellular senescence, a permanent state of cell cycle arrest, is believed to have originally evolved to limit the proliferation of old or damaged cells. However, it has been recently shown that cellular senescence is a physiological and pathological program contributing to embryogenesis, immune response, and wound repair, as well as aging and age-related diseases. Unlike replicative senescence associated with telomere attrition, premature senescence rapidly occurs in response to various intrinsic and extrinsic insults. Thus, cellular senescence has also been considered suppressive mechanism of tumorigenesis. Current studies have revealed that therapy-induced senescence (TIS), a type of senescence caused by traditional cancer therapy, could play a critical role in cancer treatment. In this review, we outline the key features and the molecular pathways of cellular senescence. Better understanding of cellular senescence will provide insights into the development of powerful strategies to control cellular senescence for therapeutic benefit. Lastly, we discuss existing strategies for the induction of cancer cell senescence to improve efficacy of anticancer therapy. [BMB Reports 2019; 52(1): 35-41]

Extracellular Vesicle as a Source of Alzheimer’s Biomarkers: Opportunities and Challenges

Lee, Seongju,Mankhong, Sakulrat,Kang, Ju-Hee MDPI 2019 INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES Vol.20 No.7

<P>Alzheimer’s disease (AD) is a chronic progressive neurodegenerative disease characterized by memory decline and cognitive dysfunction. Although the primary causes of AD are not clear, it is widely accepted that the accumulation of amyloid beta (Aβ) and consecutive hyper-phosphorylation of tau, synaptic loss, oxidative stress and neuronal death might play a vital role in AD pathogenesis. Recently, it has been widely suggested that extracellular vesicles (EVs), which are released from virtually all cell types, are a mediator in regulating AD pathogenesis. Clinical evidence for the diagnostic performance of EV-associated biomarkers, particularly exosome biomarkers in the blood, is also emerging. In this review, we briefly introduce the biological function of EVs in the central nervous system and discuss the roles of EVs in AD pathogenesis. In particular, the roles of EVs associated with autophagy and lysosomal degradation systems in AD proteinopathy and in disease propagation are discussed. Next, we summarize candidates for biochemical AD biomarkers in EVs, including proteins and miRNAs. The accumulating data brings hope that the application of EVs will be helpful for early diagnostics and the identification of new therapeutic targets for AD. However, at the same time, there are several challenges in developing valid EV biomarkers. We highlight considerations for the development of AD biomarkers from circulating EVs, which includes the standardization of pre-analytical sources of variability, yield and purity of isolated EVs and quantification of EV biomarkers. The development of valid EV AD biomarkers may be facilitated by collaboration between investigators and the industry.</P>

Dazl can bind to dynein motor complex and may play a role in transport of specific mRNAs

Lee, Kyung Ho,Lee, Seongju,Kim, Byunghyuk,Chang, Sunghoe,Kim, Soo Woong,Paick, Jae-Seung,Rhee, Kunsoo Wiley (John WileySons) 2006 The EMBO journal Vol.25 No.18

<P>Male germ cell development includes mitotic and meiotic cell divisions that are followed by dramatic morphological changes resulting in the production of spermatozoa. Genetic evidence has indicated that the DAZ family genes are critical for successful male germ cell development in diverse animals as well as humans. In the present study, we investigated the cellular functions of Dazl in the mouse male germ cells. We identified a specific interaction of Dazl with the dynein light chain, a component of the dynein-dynactin motor complex. The subcellular distribution of Dazl was microtubule-dependent and a selected number of Dazl-bound mRNAs could accumulate in the perinuclear area. Based on these results, we propose that Dazl may play a role in transport of specific mRNAs via dynein motor complex. The Dazl-bound mRNAs may be stored at specific sites and would be available for future developmental processes. Our study revealed the presence of an active mRNA transport system in mouse male germ cells.</P>

The role of Notch in regulation of inflammasome in keloid fibroblasts

( Seongju Lee ),( Donggeon Lee ),( Hye Ree Park ),( Ji Hee Jung ),( Hoon Kang ),( Jung Eun Kim ) 대한피부과학회 2019 대한피부과학회 학술발표대회집 Vol.71 No.2

Background: Notch signaling is important in keloid scar formation by regulating TGF-β pathway. I nflammasomes are involved in innate immune response, but the role is not known in the pathogenesis of keloid. Objectives: We intended to investigate whether the Notch signaling affects the activation of inflammasomes in keloid fibroblasts. Methods: Using mRNA and protein expression of inflammasomes NACHT, LRR and PYD domainscontaining protein 3 (NALP3) and ASC and proinflammatory cytokines, caspase-1 and IL-1b in the primary keloid fibroblasts was investigated. Notch-siRNA transfected keloid fibroblast cell line was used to examine the effect of Notch signaling. Results: Notch and NLRP3 inflammasome expression of keloid fibroblasts were enhanced. To find a cause of increased Notch and inflammasome expression, autophagy in keloid fibroblasts was examined. Autophagy was decreased in keloid fibroblasts and autophagy reflux analysis showed that decreased autophagic activity resulted in a reduction of Notch and inflammasome degradation in keloid fibroblasts. Notch silencing suppressed reactive oxygen species, NF-kB, α-smooth muscle actin, NLRP3, and caspase1. Conclusion: The present study demonstrated that Notch signaling involve in inflammasome-activation as well as fibrotic extracellular matrix production, and the clinical use of Notch inhibition may be useful treatment or prevention option for keloid.

Experimental and Computational Approaches to Hydrate-Based Desalination (HBD) for the Treatment of High-Salinity Water

Seongju Mun(문성주),Sungwoo Kim(김성우),Junghoon Mok(목정훈),Woojin Go(고우진),Kyung Chan Kang(강경찬),Seungmin Lee(이승민),Ju Dong Lee(이주동),Yongwon Seo(서용원) 한국신재생에너지학회 2024 한국신재생에너지학회 학술대회논문집 Vol.2024 No.5