• 제목/요약/키워드: Radiation Power

검색결과 1,902건 처리시간 0.029초

Low-Dose Radiation Stimulates the Proliferation of Normal Human Lung Fibroblasts Via a Transient Activation of Raf and Akt

  • Kim, Cha Soon;Kim, Jin Kyoung;Nam, Seon Young;Yang, Kwang Hee;Jeong, Meeseon;Kim, Hee Sun;Kim, Chong Soon;Jin, Young-Woo;Kim, Joon
    • Molecules and Cells
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    • 제24권3호
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    • pp.424-430
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    • 2007

  • The biological effects of low-dose radiation have been investigated and debated for more than a century, but its cellular effects and regulatory mechanisms remain poorly understood. This study shows the human cellular responses to low-dose radiation in CCD-18 Lu cells, which are derived from normal human lung fibroblasts. We examined a colony-forming assay for cell survival by ionizing radiation. Live cell counting and cell cycle analysis were measured for cell proliferation and cell cycle progression following low-dose irradiation. We examined Raf and Akt phosphorylation to determine the proliferation mechanism resulting from low-dose radiation. We also observed that p53 and p21 were related to cell cycle response. We found that 0.05 Gy of ionizing radiation enhanced cell proliferation and did not change the progression of the cell cycle. In addition, 0.05 Gy of ionizing radiation transiently activated Raf and Akt, but did not change phospho-p53, p53 and p21 in CCD-18 Lu cells. However, 2 Gy of ionizing radiation induced cell cycle arrest, phosphorylation of p53, and expression of p53 and p21. The phosphorylation of Raf and Akt proteins induced by 0.05 Gy of ionizing radiation was abolished by pre-treatment with an EGFR inhibitor, AG1478, or a PI3k inhibitor, LY294002. Cell proliferation stimulated by 0.05 Gy of ionizing radiation was blocked by the suppression of Raf and Akt phosphorylation with these inhibitors. These results suggest that 0.05 Gy of ionizing radiation stimulates cell proliferation through the transient activation of Raf and Akt in CCD-18 Lu cells.

  • KSCI

The potential impact of low dose ionizing ${\gamma}$-radiation on immune response activity up-regulated by Ikaros in IM-9 B lymphocytes

  • Kim, Sung-Jin;Jang, Seon-A;Yang, Kwang-Hee;Kim, Ji-Young;Kim, Cha-Soon;Nam, Seon-Young;Jeong, Mee-Seon;Jin, Young-Woo
    • 대한방사선방어학회:학술대회논문집
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    • 대한방사선방어학회 2011년도 추계 학술발표회 및 심포지엄
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    • pp.212-213
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    • 2011

  • The biological effects of low dose ionizing radiation (LDIR) remain insufficiently understood. We examined for the scientific evidence to show the biological effects of LDIR using radiation-sensitive immune cells. We found that Ikaros protein was responsed to low dose-dependent effects of gamma radiation in IM-9 B lymphocytes. Ikaros encodes zinc finger transcription factors that is important regulators of a hematopoietic stem cells (HSCs) progression to the B lymphoid lineage development, differentiation and proliferation. In this study, we observed that cell proliferation was enhanced from 10% to 20% by LDIR (0.05 Gy) in IM-9 B lymphocytes. The Ikaros protein was phosphorylated in its serine/threonine (S/T) region and decreased its DNA binding activity in the cells exposed to LDIR. We found that Ikaros phosphorylation was up-regulated by CK2/AKT pathway and the residues of ser-304 and ser-306 in Ikaros was phosphorylated by LDIR. We also observed that Ikaros protein was localized from the nucleus to the cytoplasm after LDIR and bound with Autotaxin (ENPP2, ATX) protein, stimulating proliferation, migration and survival of immune cells. In addition, we found that the lysoPLD activity of ATX was dependent on Ikaros-ATX binding activity. These results indicate that the Ikaros is an important regulator of immune activation. Therefore, we suggest that low dose ionizing radiation can be considered as a beneficial effects, stimulating the activation of immune cells.

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Occupational Radiation Exposure and Cancer in Korea

  • Jin, Young-Woo;Jeong, Mee-Seon;Moon, Ki-Eun;Jo, Min-Heui;Kang, Seong-Kyu
    • 대한방사선방어학회:학술대회논문집
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    • 대한방사선방어학회 2010년도 춘계 학술발표회 및 심포지엄
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    • pp.238-239
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    • 2010

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SEA 법에 의한 결합구조물의 음향방사파워 예측 (Prediction of Sound Radiation Power from Coupled Structures using SEA)

  • 오재응
    • 한국음향학회:학술대회논문집
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    • 한국음향학회 1987년도 학술발표회 논문집
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    • pp.24-30
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    • 1987

  • SEA method have been developed for prediction sound radiation power from vibration of machinery. In this study, sound radiation power was predicted from coupled structures by transmission of vibration, which composed of two plates welded at right angle. The predicted sound radiation power is agreement within 2 or 3 dB on octave band comparing with values obtained from direct measurements. Also, in order to prove the validity of this method in changes of sound radiation power associated with modifications to structures, rubber pad stuck on a plate. This result is agreement approximately within 3 or 5 dB.

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일사량에 따른 태양광 발전출력 분석

  • 정종욱;김선구
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2009년도 추계학술대회 논문집
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    • pp.210-210
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    • 2009

  • This paper describes the analysis results of an generated power with a inclined solar radiation. 2 different types of modules were employed to study the effect of the a inclined solar radiation on the generated power amount. As a result, it was confirmed that the generated power increased with the solar radiation and the mono crystal type cells generated higher power than the thin film type cells.

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