• Title/Summary/Keyword: Choi Chang Hak

Search Result 278, Processing Time 0.024 seconds

Extensive Bilateral Airspace Consolidation (광범위한 양측성 폐경변)

  • Choi, Su-Mi;Han, Chung-Min;Kang, Ji-Ho;Chang, Woo-Im;Kim, Chi-Hong;Kim, Kwan-Hyoung;Moon, Hwa-Sik;Song, Jeong-Sup;Park, Sung-Hak
    • Tuberculosis and Respiratory Diseases
    • /
    • v.46 no.5
    • /
    • pp.735-740
    • /
    • 1999
  • Pneumonia caused by Mycoplasma pneumoniae is usually a mild and self-limited infection. Chest films usually show patch consolidation or interstitial infiltration in the lung. We recently encountered a case of fulminant Mycoplasma pneumonia which showed rapidly progressing extensive bilateral airspace consolidation with pleural effusion. A previously healthy 19-year-old female college student was admitted to the hospital because of fever and dry cough. Chest X-ray showed large areas of airspace consolidation in both lung with pleural effusion and rapid progression of the lung lesion. The diagnosis of Mycoplasma pneumonia was made from the serologic test Here we report a case of Mycoplasma pneumonia showing unusual manifestation.

  • PDF

The Effect of Ca Addition on the Grain Growth Inhibition During Reheating Process of Al-Zn-Mg Al Alloys for Thixo-extrusion (반응고 Al-Zn-Mg계 합금의 반용융 압출을 위한 재가열 시 결정립 성장 억제에 미치는 Ca 첨가의 영향)

  • Park, Hyung-Won;Kim, Dae-Hwan;Shim, Sung-Yong;Kim, Hee-Kyung;Seong, Bong-Hak;Choi, Chang-Ock;Lim, Su-Gun
    • Journal of Korea Foundry Society
    • /
    • v.31 no.6
    • /
    • pp.347-353
    • /
    • 2011
  • There is thixo-extrusion to form high strength aluminum alloy. But, it is a problem that grains become grain coarsening during reheating process because the alloy was exposed at high temperature. In order to solve grain growth during reheating process, calcium was added in Al-Zn-Mg alloys. Primary a grain sizes of semi-solid Al-Zn-Mg-(0, 0.4, 0.6 and 0.9, wt.%)Ca were measured with image analyzer after reheating. Measured primary a grain sizes were applied to LSW(Lifshitz-Slyozov and Wagner) equation to check the effect of Ca on grain coarsening. Coarsening rate constant K values of semi-solid Al-Zn-Mg-(0, 0.4, 0.6 and 0.9, wt.%)Ca alloys were $371\;mm^3s^{-1}$, $247\;mm^3s^{-1}$, $198\;mm^3s^{-1}$ and $166 mm^3s^{-1}$, respectively. As increasing calcium content, K value decreased which means grains are refined. Also, grains of calcium addition were more spherical than that of calcium free.

Effects of ethanol extract of Nelumbo nucifera leaves on Anti-oxidation and Type I Procollagen Expression in CCD-986sk Cells (연잎 에탄올 추출물이 피부 주름에 미치는 영향)

  • Yang, Woong-Mo;Kim, Hyang-Mi;Chang, Mun-Seog;Park, Wan-Su;Kim, Won-Nam;Kim, San-Woong;Choi, Dong-Gi;Lee, Hak-Chul;Kim, Yun-Kyung;Park, Seong-Kyu
    • Herbal Formula Science
    • /
    • v.14 no.2
    • /
    • pp.67-75
    • /
    • 2006
  • The natural plants were screened for new cosmetic materials. Many parts of Nelumbo nucifera has been investigated for anti-wrinkling and anti-furrowing effects. The leaves. flowers and stamens of Nelumbo nucifera were extracted with ethanol or distilled water. The effects of cell viability and $H_2O_2-induced$ cytotoxicity were studied on CCD-986sk human fibroblast cell line by MTT assay. We measured various effects related to skin such as the synthesis of MMP-1 and type I procollagen. The ethanol extract of Nelumbo nucifera leaves (ENL) at concentrations of 30 ${\mu}g/ml$ showed maximum cell viability on CCD-986sk cells by 129.70%. and $H_2O_2-induced$ cytotoxicity was blocked by ENL (5. 10. 20. 30. and 40 ${\mu}g/ml$) concentration-dependently. The synthesis of MMP-1 and type I procollagen were positive in ENL. These results suggest that ENL has anti-oxidant and anti-furrowing effects.

  • PDF

FGF-2 inhibits TNF-α mediated apoptosis through up-regulation of Bcl2-A1 and Bcl-xL in ATDC5 cells

  • Kim, Hey-Ryun;Heo, Youn-Moo;Jeong, Kyoung-Il;Kim, Yong-Min;Jang, Hae-Lan;Lee, Kwang-Yeol;Yeo, Chang-Yeol;Kim, Sung-Hoon;Lee, Hak-Kyo;Kim, Seung-Ryul;Kim, Eung-Gook;Choi, Joong-Kook
    • BMB Reports
    • /
    • v.45 no.5
    • /
    • pp.287-292
    • /
    • 2012
  • FGF-2 is involved in cell survival, proliferation, apoptosis, and angiogenesis in a wide variety of cells. FRGRs, PI3K and MAP kinases are well known mediators of FGF signaling. Despite its known roles during many developmental processes, including osteogenesis, there are few known targets of FGF-2. In the present study, we identified Bcl2-A1 and Bcl-xL as two prominent targets involved in promoting cell survival. Pretreatment of ATDC5 cells with FGF-2 increased cell survival, while siRNAs specific for Bcl2-A1 and Bcl-xL compromised the anti-apoptotic effect of FGF-2, sensitized the cells to apoptosis triggered by TNF-${\alpha}$. Chemical inhibition of FGFR, NFkB, and PI3K activity by PD173074, pyrrolidine dithiocarbamate, and LY294002 respectively abrogated the FGF-2-mediated induction of Bcl2-A1 and Bcl-xL expression. Taken together, our data demonstrate that a subset of Bcl2 family proteins are the targets of FGF-2 signaling that promotes the survival of ATDC5 cells.

A Study on the Eddy Current Loss of the Permanent Magnet for PMSG for the Wind Turbine Application (풍력터빈 적용을 위한 PMSG용 영구자석의 와전류손실에 관한 연구)

  • Choi, Man-Soo;Moon, Chae-Joo;Sun, Rui;Chang, Young-Hak;Park, Tae-Sik;Jeong, Moon-Seon;Kwak, Seung-Hun
    • Journal of the Korean Solar Energy Society
    • /
    • v.34 no.2
    • /
    • pp.8-15
    • /
    • 2014
  • The objective of this paper is to suggest a design topology of permanent magnet synchronous generator with 2,000kW capacities for wind turbine. The suggested topology is to provide 3 split magnet PMSG instead of single magnet, and performed an analysis of eddy current loss and iron loss for suggested type using ansoft maxwell commercial program. The simulation results of suggested magnet type show there duction of eddy current loss as 13.87kW with loadless conditions and23.48kW with rated conditions, but iron loss for rotor yoke show the in creasing trend as2.2kW with loadless conditions and 0.2kW with rated conditions. The suggested 3 split maget type is to identified as more useful for 2,000kW PMSG.

Effect of Herbal Medicine on Liver Function in Korean Medical Hospital Inpatients: A Retrospective Chart Review (한약복용이 한방병원 입원환자의 간 기능에 미치는 영향에 대한 후향적 관찰)

  • Seo, Hyung-bum;Seo, Hee-jeong;Shim, So-hyun;Lee, Chan;Cho, Im- hak;Han, Chang-woo;Kim, So-yeon;Choi, Jun-yong;Park, Seong-ha;Yun, Young-ju;Hong, Jin-woo;Kwon, Jung-nam;Lee, In
    • The Journal of Internal Korean Medicine
    • /
    • v.40 no.6
    • /
    • pp.1145-1151
    • /
    • 2019
  • Objectives: The purpose of this study was to investigate liver function test results in admitted patients before and after herbal treatment. Methods: 54 subjects admitted to hospital had liver function tests (aspartate aminotransferase, alanine amino transferase, alkaline phosphatase, total bilirubin) before and after herbal treatment from 1 March 2017 to 30 June 2019. Results: Aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase were not significantly changed (p>0.05). On admission, 11 patients had abnormal liver function, while seven patients had abnormal results in alkaline phosphatase upon discharge. Three of the seven were normal when they were hospitalized. Conclusions: This study suggests that herbal treatment may have no effect on liver injury.

The AGN-Bar Connection

  • Lee, Gwang-Ho;Woo, Jong-Hak;Lee, Myung-Gyoon;Park, Chang-Bom;Choi, Yun-Young;Hwang, Ho-Seong;Lee, Jong-Hwan;Sohn, Ju-Bee
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.35 no.2
    • /
    • pp.33.1-33.1
    • /
    • 2010
  • We investigate the relation between the presence of bars in galaxies and AGN activities. Bars are believed to play an important role in fueling of AGN. Although there have been many previous studies on this topic, "the AGN-Bar Connection" is still an open question. To better understand the connection, we use a volume-limited sample of 9,726 late-type galaxies brighter than $M_r$=-19.5+5logh at $0.02{\leqq}z{\leqq}0.05489$, drawn from SDSS DR7. Among galaxies in the sample, 1,963 galaxies are classified as AGN-host galaxies based on the emission-line ratios while barred galaxies are identified by visual inspection. The bar fraction in AGN host galaxies (22.5%) is 3-times higher than in star-forming galaxies (8.6%). However, this trend is simply caused by the fact that the bar fraction increases with galaxy mass or luminosity and that AGN host galaxies are on average more massive than star-forming galaxies. Nevertheless, we find that among AGN host galaxies, the bar fraction increases with the Eddington ratio $(L_{[OIII]}/M_{[BH]})$, and this trend remains intact even at fixed galaxy luminosity and stellar velocity dispersion. These results imply that bars play a role in triggering AGNs.

  • PDF

A Study on non-linear trajectory shaped apparatus applied solar tracking device (비선형 궤적형상을 적용한 태양광 추적장치에 대한 연구)

  • Han, Jae-Hyeon;Moon, Chae-Joo;Chang, Young-Hak;Choi, Man-Soo;Kim, Young-Gon;Jeong, Moon-Seon
    • The Journal of the Korea institute of electronic communication sciences
    • /
    • v.10 no.11
    • /
    • pp.1277-1284
    • /
    • 2015
  • In this paper, 1-axis tracking mechanism of solar-cell panel, which is able to rotate from -90 degree to +90 degree for maintaining always perpendicular between solar-cell panel and sun, was analyzed. This paper propose the non-linear shaped guidance and analyze mathematical formulation of non-linear shape. This analysis shows that it is able to identify the non-linear shaped guidance. Especially, even though the length of rotating link have changed, the non-linear shaped guidance could be confirm with proper size. As effectiveness of this result, 10% efficiency rising is estimated compared to the conventional 1-axis tracking mechanism and also optimal non-linear shaped guidance can be suggested for various size of solar-cell panel. Therefore the flexible mass-production is possible for various size of non-linear shaped guidance.

Performance Examination and Comparison of Steel Beam-Column Connection in SM570TMC for Mixed-Use (고강도강 혼용 사용을 위한 SM570TMC강 보-기둥 접합부의 성능평가 및 해석 비교)

  • Kim, Moonjeong;Cho, Sukhee;Ha, Tae-Uk;Kang, Chang-Hoon;Choi, Woo-Hyuk;Kim, Jung-Hak
    • Journal of the Korean Society for Advanced Composite Structures
    • /
    • v.4 no.3
    • /
    • pp.22-29
    • /
    • 2013
  • In recent years, the construction of high-rise buildings are promoted. According to these, there are many needs about new technologies to strengthen the building performance and high-strength steel is regarded as one of these for promoting building performance. In Korea, high-strength steels which stress are over 600MPa are on market and in aborad, super high-strength steels over 1000MPa are developing and they expected to promote the building performance. But there are still doubts about applying high-strength steel members because of size effect and worry of brittle fracture. In this reports, we propose results of performance and analysis tests for use with general steel. We propose the characteristic of high-strength steels first and next the results of performance test to show they satisfy the performance that designers expect. And last, we compare the results of test and analysis for acquire the alanysis reliability in non-linear analysis with high-strength steels.

Simultaneous Determination of Fluorene and Anthracene by Synchronous Spectrofluoremetry (동시화 형광분광법에 의한 fluorene과 anthracene의 동시정량)

  • Lee, Sang Hak;Han, Yung Ji;Son, Bum Mok;Choi, Jong Ha;Kim, Chang Jin
    • Analytical Science and Technology
    • /
    • v.15 no.5
    • /
    • pp.393-398
    • /
    • 2002
  • A method to determine simultaneously fluorene and anthracene in aqueous solution by synchronous fluorescence spectrometry has been studied. The emission characteristics and optimum wavelength interval (${\Delta}{\lambda}$) for synchronous spectra of fluorene and anthracene in aqueous solution were investigated. The optimum wavelength interval (${\Delta}{\lambda}$) was found to be 50 nm. The calibration curve for fluorene and anthracene in the synthetic mixture solution of both compounds was linear over the range from $5.0{\times}10^{-8}M$ to $1.0{\times}10^{-3}M$ and from $5.0{\times}10^{-8}M$ to $1.0{\times}10^{-3}M$ for fluorene and anthracene, respectively. The detection limit was $3.0{\times}10^{-9}M$ and $7.0{\times}10^{-9}M$, for fluorene and anthracene, respectively under the optimal wavelength interval.