• Title/Summary/Keyword: MRC division

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Dust particles-induced intracellular Ca2+ signaling and reactive oxygen species in lung fibroblast cell line MRC5

  • Lee, Dong Un;Ji, Min Jeong;Kang, Jung Yun;Kyung, Sun Young;Hong, Jeong Hee
    • The Korean Journal of Physiology and Pharmacology
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    • v.21 no.3
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    • pp.327-334
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    • 2017
  • Epidemiologic interest in particulate matter (PM) is growing particularly because of its impact of respiratory health. It has been elucidated that PM evoked inflammatory signal in pulmonary epithelia. However, it has not been established $Ca^{2+}$ signaling mechanisms involved in acute PM-derived signaling in pulmonary fibroblasts. In the present study, we explored dust particles PM modulated intracellular $Ca^{2+}$ signaling and sought to provide a therapeutic strategy by antagonizing PM-induced intracellular $Ca^{2+}$ signaling in human lung fibroblasts MRC5 cells. We demonstrated that PM10, less than $10{\mu}m$, induced intracellular $Ca^{2+}$ signaling, which was mediated by extracellular $Ca^{2+}$. The PM10-mediated intracellular $Ca^{2+}$ signaling was attenuated by antioxidants, phospholipase blockers, polyADPR polymerase 1 inhibitor, and transient receptor potential melastatin 2 (TRPM2) inhibitors. In addition, PM-mediated increases in reactive oxygen species were attenuated by TRPM2 blockers, clotrimazole (CLZ) and N-(p-amylcinnamoyl) anthranilic acid (ACA). Our results showed that PM10 enhanced reactive oxygen species signal by measuring DCF fluorescence and the DCF signal attenuated by both TRPM2 blockers CLZ and ACA. Here, we suggest functional inhibition of TRPM2 channels as a potential therapeutic strategy for modulation of dust particle-mediated signaling and oxidative stress accompanying lung diseases.

Analysis of Smart Antenna Performance Improving the Robustness of OFDM to Rayleigh Fading (레일리 페이딩 내구성을 개선시키는 OFDM 스마트안테나의 성능 분석)

  • Hong, Young-Jin
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.48 no.4
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    • pp.53-60
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    • 2011
  • In order to augment the robustness of OFDM system to Rayleigh multipath fading, there exist two smart antenna algorithms, namely, Pre-FFT smart antenna and Post-FFT smart antenna. After the mathematical modeling of both smart antenna algorithms, computer simulations have been carried to compare and analyze the performance of generalized eigen problem based Pre-FFT algorithm and the performance of Wiener solution based Post-FFT algorithm. It has been shown that the Post-FFT smart antenna far outperforms the Pre-FFT smart antenna due to the computational complexities. Especially it is so when the multipath signal arrives at beyond the guard interval and a rich co-channel interferer is introduced. Performance of a subcarrier clustering method proposed to lessen the computing load has been compared to that of a typical Wiener solution based Post-FFT smart antenna. Performance comparison between MRC(Maximum Ratio Combining) diversity based Post-FFT algorithm and typical Post-FFT algorithm has also been carried.

Assessment of Flood Probability Based on Temporal Distribution of Forecasted-Rainfall in Cheongmicheon Watershed (예보강우의 시간분포에 따른 청미천 유역의 홍수 확률 평가)

  • Lee, Hyunji;Jun, Sang Min;Hwang, Soon Ho;Choi, Soon-Kun;Park, Jihoon;Kang, Moon Seong
    • Journal of The Korean Society of Agricultural Engineers
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    • v.62 no.1
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    • pp.17-27
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    • 2020
  • The objective of this study was to assess the flood probability based on temporal distribution of forecasted-rainfall in Cheongmicheon watershed. In this study, 6-hr rainfalls were disaggregated into hourly rainfall using the Multiplicative Random Cascade (MRC) model, which is a stochastic rainfall time disaggregation model and it was repeated 100 times to make 100 rainfalls for each storm event. The watershed runoff was estimated using the Clark unit hydrograph method with disaggregated rainfall and watershed characteristics. Using the peak discharges of the simulated hydrographs, the probability distribution was determined and parameters were estimated. Using the parameters, the probability density function is shown and the flood probability is calculated by comparing with the design flood of Cheongmicheon watershed. The flood probability results differed for various values of rainfall and rainfall duration. In addition, the flood probability calculated in this study was compared with the actual flood damage in Cheongmicheon watershed (R2 = 0.7). Further, this study results could be used for flood forecasting.

Arrest of Cell Growth by Inhibition of Endogenous Reverse Transcription Activity in Cancer and Somatic Cell Lines (사람의 암세포주 및 정상세포주에서 역전사 효소의 억제에 의한 세포 성장의 제한)

  • Mi-Jeong Kim;Sung-Ho Lee;Jong-Kuen Park;Byeong-Gyun Jeon
    • Journal of Life Science
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    • v.34 no.6
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    • pp.365-376
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    • 2024
  • The present study assessed the cytotoxic effects on cell growth and senescence in human cancer (A-549, AGS, HCT-116, MDA-MB-231, and U 87-MG) and normal (MRC-5 and mesenchymal stem cells) cell lines treated with efavirenz (EFA), an inhibitor of non-nucleoside reverse transcriptase (RTase). Following EFA treatment, the half-maximal inhibitory concentration (IC50) values were approximately 15 µM, and the IC50 value was significantly (p<0.05) lower in the cancer cell lines, compared to normal cell lines. After determining the IC50 values against EFA, each cell line was treated with 15 µM EFA for up to one week. Significant (p<0.05) decreases in endogenous RTase and telomerase activity were observed in the cancer cell lines. RTase and telomerase activity were absent or detected at very low levels in both EFA-untreated and treated MRC-5 and MSC normal cells. The cell doubling time (CDT) was also significantly (p<0.05) prolonged by the decreased cell growth rate in the EFA-treated cancer cell lines compared to the untreated cell lines. Furthermore, EFA-treated cancer cells displayed a high number of cells with a high intensity of senescence-associated ß-galactosidase activity (SA-ß-gal activity), compared to the untreated cells. The present study showed that inhibition of RTase activity induces cellular senescence and arrests cell growth in human cancer cell lines; however, normal cell lines showed greater tolerance against EFA. RTase treatment could offer optional chemotherapy for cancer treatment in human cancer cell lines with high RTase activity.

Validation of the Korean Version of the Bronchiectasis Health Questionnaire

  • Kim, Hyun Kuk;Lee, Hyun;Kim, Sang-Heon;Choi, Hayoung;Lee, Jae Ha;Lee, Jae Seung;Lee, Sei Won;Oh, Yeon-Mok
    • Tuberculosis and Respiratory Diseases
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    • v.83 no.3
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    • pp.228-233
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    • 2020
  • Background: The Bronchiectasis Health Questionnaire (BHQ) is a simple and repeatable, self-reporting health status questionnaire for bronchiectasis. We have translated the original version of the BHQ into Korean using a standardized methodology. The purpose of this study was to assess the validity of the Korean version of the BHQ (K-BHQ) with Korean patients. Methods: Stable state patients with bronchiectasis from two academic hospitals were enrolled in this study. The validity was assessed by investigating the relationship between the K-BHQ scores and the Korean version of the Chronic Obstructive Pulmonary Disease Assessment Test (K-CAT) scores. We also investigated the relationship between the K-BHQ scores and other variables of the modified Medical Research Council's (mMRC) dyspnea scale, lung function, and exacerbations. Results: A total of 126 patients with bronchiectasis were enrolled. The mean age was 64.3 (standard deviation [SD], 9.7). Women comprised 53.2% of the patients. The mean forced expiratory volume in one second (FEV1) was 60% of the predicted value (SD, 18.9%); the mean K-CAT score was 17.6 (SD, 9.1). The K-BHQ scores correlated strongly with the K-CAT scores (r=-0.656, p<0.001). There was significant correlation between the K-BHQ scores and the mMRC dyspnea scale (ρ=-0.409, p<0.001), FEV1 (r=0.406, p<0.001), and number of exacerbations requiring hospitalization (ρ=-0.303, p=0.001). Conclusion: The K-BHQ is valid for assessing the health-related quality of life or health status of Korean bronchiectasis patients.

Design of an integrated network management system for telecom subsystem in offshore plants

  • Kang, Nam-seon;Kim, Nam-hun;Lee, Seon-ho;Kim, Young-goon;Yoon, Hyeon-kyu
    • Journal of Advanced Marine Engineering and Technology
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    • v.39 no.8
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    • pp.863-869
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    • 2015
  • This study analyzed the offshore plant industry and related regulations such as ISO, IEC, and Norsok Standards to develop an integrated network management system (INMS) capable of both on-site and remote management and configuration of IP-based network equipment in offshore plants. The INMS was designed based on actual specifications and POS plans, and a plan of management was verified through an offshore plant engineering company. Various modules such as PAGA interface modules, CCTV, IP-PBX, and HF-radio communication modules were developed for system implementation. Protocol and data design and screen design were followed by framework development and introduction of the automatic satellite communication function.

Receive Diversity for OFDM Systems with Cochannel Interference (동일 채널 간섭을 고려한 OFDM 시스템의 수신 다이버시티 기법)

  • Seo, Bo-Seok
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2005.11a
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    • pp.95-98
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    • 2005
  • 이 논문에서는 동일채널 간섭이 존재하는 채널 환경에서 OFDM(Orthogonal Frequency Division Multiplexing) 시스템의 수신 다이버시티 결합 방법을 제시한다. 제시된 방법에서는 각 수신 안테나로부터의 수신 신호를 주파수 영역에서 부반송파 단위로 결합하며, 잡음과 간섭 전력을 고려한 MRC(Maximum Ratio Combining)를 적용한다. 잡음과 간섭 전력은 채널의 제한된 지연확산에 기인하는 주파수 대역에서의 상관특성(coherency)을 이용하여 인접한 몇 개의 부채널에 대해 잡음과 간섭 전력의 평균을 취함으로써 더 정확한 추정치를 얻는다. IEEE 802.11a 무선 LAN 규격에서 모의실험 결과 제안방법은 기존 방시에 비해 SNR을 2-4 dB 개선하였으며, 정확하게 SINR을 추정한 경우에 대해 1 dB 이내로 접근하는 결과를 나타내었다.

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Comparative Analysis on Anti-aging, Anti-adipogenesis, and Anti-tumor Effects of Green Tea Polyphenol Epigallocatechin-3-gallate (녹차의 폴리페놀류인 에피갈로카테킨-3-갈레이트에 의한 항노화, 항비만 및 항암효과에 대한 비교 분석)

  • Lim, Eun-Ji;Kim, Min-Jae;Kim, Hyeon-Ji;Lee, Sung-Ho;Jeon, Byeong-Gyun
    • Journal of Life Science
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    • v.28 no.10
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    • pp.1201-1211
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    • 2018
  • The study compared the anti-aging, anti-adipogenesis, and anti-tumor effects of epigallocatechin-3- gallate (EGCG) in various cancer cell lines (SNU-601, MKN74, AGS, MCF-7, U87-MG, and A-549) and normal cell lines (MRC-5 fibroblasts, dental tissue-derived mesenchymal stem cells [DSC], and 3T3-L1 pro-adipocytes). Half inhibitory concentration ($IC_{50}$) values were significantly (p<0.05) higher in normal cell lines (~50 uM), when compared to that in cancer cell lines (~10 uM). For anti-aging effects, MRC-5 and DSC were exposed to 10 uM EGCG for up to five passages that did not display any growth arrest. Population doubling time and senescence-related ${\beta}-galactosidase$ ($SA-{\beta}-gal$) activity in treated cells were similar to untreated cells. For anti-adipogenic effects, mouse 3T3-L1 pre-adipocytes were induced to adipocytes in an adipogenic differentiation medium containing 10 uM EGCG, but adipogenesis in 3T3-L1 cells was not inhibited by EGCG treatment. For anti-tumor effects, the cancer cell lines were treated with 10 uM EGCG. PDT was significantly (p<0.05) increased in EGCG-treated SNU-601, AGS, MCF-7, and U87-MG cancer cell lines, except in MKN74 and A-549. The level of telomerase activity and cell migration capacity were significantly (p<0.05) reduced, while $SA-{\beta}-gal$ activity was highly up-regulated in EGCG treated-cancer cell lines, when compared to that in untreated cancer cell lines. Our results have demonstrated that EGCG treatment induces anti-tumor effects more efficiently as noted by decreased cell proliferation, cell migration, telomerase activity, and increased $SA-{\beta}-gal$ activity than inducing anti-aging and anti-adipogenesis. Therefore, EGCG at a specific concentration can be considered for a potential anti-tumor drug.

Cytotoxicity of Particulate Matter in Various Human Cells Lines (미세먼지가 다양한 사람 세포주에 미치는 세포 독성)

  • Lee, Ji-Hyeon;Lee, Joo-Yeong;Kim, Mi-Jeong;Kim, Hyeon-Ji;Lee, Sung-Ho;Jeon, Byeong-Gyun
    • Journal of Life Science
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    • v.29 no.6
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    • pp.724-734
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    • 2019
  • The present study investigated the cytotoxicity of particulate matter (PM) derived from car air filter (outdoor PM) and home cleaner filter (indoor PM) in the various human cell lines. Each outdoor and indoor PM were harvested by ethanol extraction method, subsequently sieved with 10 um filter paper, sterilized with autoclave and added to culture media. The half maximal inhibitory concentration ($IC_{50}$) values was significantly (p<0.05) lower in the outdoor PM, compared with indoor PM, and the significantly (p<0.05) higher $IC_{50}$ values were observed in the cancer cell lines (A-549 lung adenocarcinoma and AGS stomach adenocarcinoma), than those of normal MRC-5 fibroblasts and dental papilla tissue derived-mesenchymal stem cells (DSC). After being exposed to $100{\mu}g/ml$ outdoor PM for 7 days, the population doubling time (PDT) was significantly (p<0.05) increased in especially MRC-5 and DSC cell lines, compared with untreated cell lines. Further, the expression of senescence-associated ${\beta}$-galactosidase activity was up-regulated in all the cells exposed to outdoor PM than those of untreated control. Besides, the expression level of inflammation-associated genes, such as cyclooxygenase-2 (COX-2) and interleukin-6 (IL-6) was found to be significantly (p<0.05) increased in the outdoor PM-treated cell lines than those of untreated cell lines. Our results showed that PM induces the cytotoxicity via arrest of cell growth, cell damage and inflammation response.

A Study on the OFDM System Using Multi-Block SDM (Multi-Block SDM을 이용한 OFDM 시스템에 관한 연구)

  • Lee, Kyu-Jin;Kim, Ji-Sung;Kim, Nam-Il;Lee, Kye-San
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.7 no.5
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    • pp.122-130
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    • 2008
  • Improving the transmission rates of multi-media delivery, such as moving pictures and internet services, has become increasingly important in modern society. To satisfy such high data rate requirements, the MIMO technique, which has the capacity to transmit large amounts of data using limited frequency resources, was developed. The Space Division Multiplexing (SDM) system is one of the MIMO techniques to be able to improve the transmission capacity. However, it is unable to achieve diversity gain because of interference due to the use of multiple antennas. In this paper, an SDM system that utilizes a Multi-Block method as an advanced transmission technique in a wireless communication system to obtain diversity gain is proposed and discussed fur the performance of the proposed system.

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