• Title/Summary/Keyword: 분절형 PC

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Performance Measurement of Split PC Sleepers for Safety in Maintenance Work (분절형 PC침목의 안전성 확보를 위한 성능평가 시험)

  • Eum, Ki-Young;Um, Ju-Hwan;Sin, Seung-Kwon;Lee, Chang-Hun
    • Journal of the Korean Society of Hazard Mitigation
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    • v.6 no.4 s.23
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    • pp.1-6
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    • 2006
  • In terms of the speed-up of the conventional line, the research for a improved turnout was carried out continually around world. A turnout is known that it is the most unstable equipment structurally in the rail system. So, the turnout is needed more stable structure. An accurate assembly of turnout affects traveling qualify of turnout area and running safety. Therefore, a turnout which is pre-assembled at a factory by using the split PC sleeper is transported to construction site recently in advanced countries. In this paper, the performance measurements which estimate the safety of the split PC sleepers which are adopted for the first time to improve performance of turnout are implemented indoors. The split PC sleeper is one of components of the improved turnout. The test is considered of the worst ballast condition under the maintenance work as like STT(Swithc Tie Tamper) or MTT(Multiple Tie Tamper). These experiments results indicate that structural safety for the expansion joint of the split PC sleepers.

Study and Field application of Segmented PC sleeper for Turnout (분절형 PC 침목 분기기의 연구 및 실용화)

  • Hwang Kwang-Ha;Park June-Teak;Lee Joong-Su;Park Yong-Gul;Jung Woo-Jin
    • Proceedings of the KSR Conference
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    • 2004.10a
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    • pp.739-745
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    • 2004
  • In reference to conventional line speed-up and improvement railway, accurate assembly of turnout affects traveling quality of turnout area and running safety. Because of heavy weight and a large volume of the long sleepers and car limit, transport and construction of the P.C(prestress concrete) sleeper turnout is the most difficult process. the prerequisite for trouble-free transport of the factory pre-assembled major turnout components is achieved through division of long sleepers. So, in this paper we investigate structural safety of segmented sleeper which is adopted for the first time to improve performance of turnout and, new construction method.

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Gamma Irradiation Induces a Caspase-dependent Apoptotic Mechanism in Human Prostate Cancer PC-3 Cells (인간 남성호르몬 비의존형 전립선 PC-3 암세포에서 감마선의 Caspase-의존성 세포자멸사 유도 효과)

  • Chang, Jeong-Hyun;Kim, Dong-Hyun;Jeon, Gye-Rok;Kwon, Heun-Young
    • Journal of Life Science
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    • v.18 no.8
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    • pp.1042-1048
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    • 2008
  • Prostate cancer is the most predominant cancer in men and related death rate increases every year. Till date, there is no effective therapy for androgen independent prostate cancer. To investigate the mechanism for cell growth inhibition or apoptosis in human androgen independent prostate cancer PC-3 cells after gamma irradiation. The aim of this study was to examine the potential of gamma irradiation to induce apoptosis in PC-3 cells and to assess the mechanism of gamma irradiation-induced apoptosis. Five different assays were employed in this study: cell proliferation assay, morphological assessments of apoptotic cells, DNA fragmentation analysis, quantification of apoptosis by annexin V (AV) and propidium iodide (PI) staning, and western blot analysis. Cell viability was inversely related to radiation dose. DAPI-positive cells were detected 48 hr after 40 Gy radiation exposure. And nuclear morphological changes of cells were observed by gamma irradiation. DNA ladder patterns in the cells exposed to gamma-radiation were appeared at 24 hr. Also, gamma irradiation induces apoptosis of PC-3 cells via Caspase3, Bax and PARP-dependent fashion.

Resveratrol Induces Apoptosis in Primary Human Prostate Cancer Cells (Primary 인체 전립선 암세포에서 Resveratrol의 Apoptosis 유도 효과)

  • Kang, Hye-In;Kim, Jae-Yong;Cho, Hyun-Dong;Park, Kyung-Wuk;Kang, Jum-Soon;Seo, Kwon-Il
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.39 no.8
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    • pp.1119-1125
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    • 2010
  • To evaluate resveratrol as a prostate cancer preventive material, we investigated its anti-proliferative and apoptotic effects in RC-58T/h/SA#4 primary human prostate cancer cells. Resveratrol significantly decreased the number of viable RC-58T/h/SA#4 cells in a dose- and time-dependent manner. Resveratrol showed cytotoxicity against RC-58T/h/SA#4, LNCaP, PC-3 human prostate cancer cells with $IC_{50}$ values of 245, 320 and $340\;{\mu}M$, respectively. However the cytotoxic potential of resveratrol against normal RWPE-1 cells was lower ($IC_{50}=982\;{\mu}M$). Resveratrol induced cell death as evidenced by the increased formation of apoptotic bodies, nuclear condensation, sub-G1 phase, and DNA fragmentation. Resveratrol activated initiator caspases 8, and 9 as well as effector caspase 3 in a dose-dependent manner. Furthermore, the general caspase inhibitor z-VAD-fmk significantly inhibited resveratrol-induced apoptosis compared to cells without treatment. These results clearly indicate that resveratrol-induced apoptosis was dependent on caspase activation. Further, resveratrol modulated the down regulation of Bcl-2 (anti-apoptotic), and Bid. However, the level of Bax (pro-apoptotic) remained unchanged. These results suggest that resveratrol induced apoptosis in RC-58T/h/SA#4 cells via a mitochondrial-mediated caspase-dependent pathway, suggesting therapeutic potential against prostate cancer.