• Title/Summary/Keyword: K-Ras

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Effect of Protein Kinase C Inhibitor (PKCI) on Radiation Sensitivity and c-fos Transcription Activity (Protein Kinase C Inhibitor (PKCI)에 의한 방사선 민감도 변화와 c-fos Proto-oncogene의 전사 조절)

  • Choi Eun Kyung;Chang Hyesook;Rhee Yun-Hee;Park Kun-Koo
    • Radiation Oncology Journal
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    • v.17 no.4
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    • pp.299-306
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    • 1999
  • Purpose : The human genetic disorder ataxia-telangiectasia (AT) is a multisystem disease characterized by extreme radiosensitivity. The recent identification of the gene mutated in AT, ATM, and the demonstration that it encodes a homologous domain of phosphatidylinositol 3-kinase (PI3-K), the catalytic subunit of an enzyme involved in transmitting signals from the cell surface to the nucleus, provide support for a role of this gene in signal transduction. Although ionizing radiation was known to induce c-fos transcription, nothing is known about how ATM or PKCI mediated signal transduction pathway modulates the c-fos gene transcription and gene expression. Here we have studied the effect of PKCI on radiation sensitivity and c-fos transcription in normal and AT cells. Materials and Methods: Normal (LM217) and AT (AT5BIVA) cells were transfected with PKCI expression plasmid and the overexpression and integration of PKCI was evaluated by northern blotting and polymerase chain reaction, respectively. 5 Gy of radiation was exposed to LM and AT cells transfected with PKCI expression plasmid and cells were harvested 48 hours after radiation and investigated apoptosis with TUNEL method. The c-fos transcription activity was studied by performing CAT assay of reporter gene after transfection of c-fos CAT plasmid into AT and LM cells. Results: Our results demonstrate for the first time a role of PKCI on the radiation sensitivity and c-fos expression in LM and AT cells. PKCI increased radiation induced apoptosis in LM cells but reduced apoptosis in AT cells. The basal c-fos transcription activity is 70 times lower in AT cells than that in LM cells. The c-fos transcription activity was repressed by overexpression of PKCI in LM cells but not in AT cells. After induction of c-fos by Ras protein, overexpression of PKCI repressed c-fos transcription in LM cells but not in AT cells Conclusion: Overexpression of PKCI increased radiation sensitivity and repressed c-fos transcription in LM cells but not in AT cells. The results may be a. reason of increased radiation sensitivity of AT cells. PKCI may be involved in an ionizing radiation induced signal transduction pathway responsible for radiation sensitivity and c-fos transcription. The data also provided evidence for novel transcriptional difference between LM and AT cells.

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Numerical Model Application for Analysis of Flood Level Mitigation due to Retention-Basin (강변저류지 홍수위 저감효과 분석을 위한 수치모형 적용)

  • Cho, Gilje;Rhee, Dong Sop;Kim, Hyung-Jun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.1
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    • pp.495-505
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    • 2014
  • The retention basin is a river-facility for the flood mitigation by storing the river flow temporarily. The new 3 retention basins are installed in these regions YeoJu, NaJu, YoungWol by the Large River Management Project. In this study, 1D and 2D numerical flow simulation are conducted to evaluate the reduction effect of the peak flood stage for the YeoJu retention basin. HEC-RAS and FLDWAV models are used for 1D simulation with the option of retention basin. CCHE2D model is used for 2D simulation with the same hydrograph used in 1D simulation. It is verified that the peak flood stage is reduced very largely about 0.13 m near the overtopping section of the levee in 1D simulation. It is verified that the peak flood stage is reduced very largely about 0.20 m at the upstream-end of the simulated reach in 2D simulation. 2D simulation for the retention basin is more reasonable because physical characteristics of topography in the model, and also more advantageous for the evaluation of the flow characteristics of the in- and outside of the retention basin on the results of simulation of this study.

Determine the Length of the Side-Weir of Side-Weir Detention Basin Considering the Uncertainty of the Water Level in River (하천 수위 예측의 불확실성을 고려한 강변저류지 횡월류부 길이 결정 기법)

  • Kim, Seojun;Kim, Sanghyuk;Yoon, Byungman
    • Journal of Korea Water Resources Association
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    • v.48 no.8
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    • pp.673-683
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    • 2015
  • The existing flood protection in rivers has shown the limitation due to the urbanization around rivers and the abnormal climate. Thus, the demand for the constructions of side-weir detention basin are being increased as a part of integrated watershed flood protection plan. It is necessary to estimate the quantitative flood-control effect for including the side-weir detention basin in flood-control measures. For the determination, it is required to reduce the uncertainty of the design factors which can affect the flood-control effect of side-weir detention basin. Among the factors, however, the water level in river always contains uncertainty. Therefore, the design method considering the uncertainty is required. For the reasons, the design method considering uncertainty of the water level in river is suggested in this study with using the length of side-weir which is relatively easy-determinable by designers. Therefore, it is examined how the variation of the length of side-weir can affect the flood-control effect, using HEC-RAS, and then the method to determine the side-weir length considering the uncertainty of the water level in river through results from analyses. Since the uncertainty of the water level in river can be taken into account in the suggested design method, it is evaluated that the design method is more effective to suggest the flood-control effect of the side-weir type detention basin with higher safety side.

Review of Roughness Coefficient Characteristics for Rivers in Korea (실측 자료를 이용한 국내하천의 조도계수 특성검토)

  • Kim, Joo-Young;Kim, Han-Sup;Lee, Jong-Kyu
    • Journal of Korea Water Resources Association
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    • v.44 no.9
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    • pp.695-710
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    • 2011
  • Manning's roughness coefficients for the Han River, the Nakdong River and the Geum River were determined by the hydraulic models using their field measurements. The roughness coefficients of present study were compared with the ones of the conventional references. The hydraulic models, such as HEC-2, HEC-RAS and FLDWAV models, are usually applied to a river flow analysis. In order to compute the accurate flood level with the numerical models, accurate information about river sections, the upstream and downstream boundary conditions, and the appropriate roughness coefficients are indispensable. It is hard to obtain the reasonable roughness coefficient of the river, in the other hand the river cross sectional data and the boundary conditions are relatively easy to acquire. The coefficient values from the references are applied in many applications without considering the variation of locations and discharges of the river, or the values are unreasonably estimated. The final results from this study will give a reasonable and important data to perform the flood routing in the Korea river.

Connection between the Amplitude Variations of the GPS Radio Occultation Signals and Solar Activity

  • Pavelyev, A.G.;Liou, Y.A.;Wickert, J.;Pavelyev, A.A.
    • Proceedings of the KSRS Conference
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    • 2008.10a
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    • pp.348-357
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    • 2008
  • The classification of the effect of ionospheric disturbances on the radio occultation signal amplitude has been introduced based on an analysis of more than 2000 seances of radio occultation measurements per formed with the help of the CHAMP German satellite. The dependence of the histograms of variations in the radio occultation signal amplitude on the IMF variation index has been revealed. It has been indicated that it is possible to introduce the radio occultation index characterizing the relation between ionospheric disturbances and solar activity. An amplitude radio occultation (RO) method is proposed to study connection between the ionospheric and solar activity on a global scale. Sporadic amplitude scintillation observed in RO experiments contain important information concerning the seasonal, geographical, and temporal distributions of the ionospheric disturbances and depend on solar activity. The probability of strong RO amplitude variations (RO $S_4$ index greater than 0.2) in the CHAMP RO signals diminishes sharply with the weakening of solar activity from 2001 to 2008. The general number of RO events with strong amplitude variations can be used as an indicator of the ionospheric activity. We found that during 2001-2008 the daily globally averaged RO $S_{4a}$ index depends essentially on solar activity. The maximum occurred in January 2002, minimum has been observed in summer 2008. Different temporal behavoir of $S_{4a}$ index has been detected for polar (with latitude greater than $60^{\circ}$) and low latitude (moderate and equatorial) regions. For polar regions $S_{4a}$ index is slowly decreasing with solar activity. In the low latitude areas $S_{4a}$ index is sharply oscillating, depending on the solar ultraviolet emission variations. The different geographical behavoir of $S_{4a}$ index indicates different origin of ionospheric plasma disturbances in polar and low latitude areas. Origin of the plasma disturbances in the polar areas may be connected with influence of solar wind, the ultraviolet emission of the Sun may be the main cause of the ionospheric irregularities in the low latitude zone. Therefore, the $S_{4a}$ index of RO signal is important radio physical indicator of solar activity.

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Optimal parameter derivation for Muskingum method in consideration of lateral inflow and travel time (측방유입유량 및 유하시간을 고려한 Muskingum 최적 매개변수 도출)

  • Kim, Sang Ho;Kim, Ji-sung;Lee, Chang Hee
    • Journal of Korea Water Resources Association
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    • v.50 no.12
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    • pp.827-836
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    • 2017
  • The most important parameters of the Muskingum method, widely used in hydrologic river routing, are the storage coefficient and the weighting factor. The Muskingum method does not consider the lateral inflow from the upstream to the downstream, but the lateral inflow actually occurs due to the rainfall on the watershed. As a result, it is very difficult to estimate the storage coefficient and the weighting factor by using the actual data of upstream and downstream. In this study, the flow without the lateral inflow was calculated from the river flow through the hydraulic flood routing by using the HEC-RAS one-dimensional unsteady flow model, and the method of the storage coefficient and the weighting factor calculation is presented. Considering that the storage coefficient relates to the travel time, the empirical travel time formulas used in the establishment of the domestic river basin plan were applied as the storage coefficient, and the simulation results were compared and analyzed. Finally, we have developed a formula for calculating the travel time considering the flow rate, and proposed a method to perform flood routing by updating the travel time according to the inflow change. The rise and fall process of the flow rate, the peak flow rate, and the peak time are well simulated when the travel time in consideration of the flow rate is applied as the storage coefficient.

Remote Acoustic Sensing Methods for Studies in Oceanology

  • Akulichev, Victor A.;Bezotvetnykh, Vladimir V.;Burenin, Alexander V.;Voytenko, Evgeny A.;Kamenev, Sergey I.;Morgunov, Yury N.;Polovinka, Yury A.;Strobykin, Dmitry S.
    • Ocean Science Journal
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    • v.41 no.2
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    • pp.105-111
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    • 2006
  • In this paper, the lines of investigation on a problem of the development of remote acoustic sensing methods in oceanology are formulated. This paper summarizes the results of investigations into the possibilities for monitoring temperature and flow fields in shallow seas. In the discussed experiments, the instrumentation being constituents of the complex for long-duration remote monitoring of marine medium climatic variability and that of the acoustic tomography of shallow sea dynamic processes is used. The acoustic instruments were located on the POI FEB RAS acousto-hydrophysical polygon (Pacific Oceanological Institute, Far Eastern Branch of the Russian Academy of Sciences) near the Gamov Peninsula. Acoustic receiving and transmitting systems operating with multiplex phase-manipulated signals (of M-codes) at frequency range 250-2500 Hz form the basis for this complex.

Bacillus anthracis Spores Influence ATP Synthase Activity in Murine Macrophages

  • Seo, Gwi-Moon;Jung, Kyoung-Hwa;Kim, Seong-Joo;Kim, Ji-Cheon;Yoon, Jang-Won;Oh, Kwang-Keun;Lee, Jung-Ho;Chai, Young-Gyu
    • Journal of Microbiology and Biotechnology
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    • v.18 no.4
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    • pp.778-783
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    • 2008
  • Anthrax is an infectious disease caused by toxigenic strains of the Gram-positive bacterium Bacillus anthracis. To identify the mitochondrial proteins that are expressed differently in murine macrophages infected with spores of B. anthracis Sterne, proteomic and MALDI-TOF/MS analyses of uninfected and infected macrophages were conducted. As a result, 13 mitochondrial proteins with different expression patterns were discovered in the infected murine macrophages, and some were identified as ATP5b, NIAP-5, ras-related GTP binding protein B isoform CRAa, along with several unnamed proteins. Among these proteins, ATP5b is related to energy production and cytoskeletal rearrangement, whereas NIAP-5 causes apoptosis of host cells due to binding with caspase-9. Therefore, this paper focused on ATP5b, which was found to be down regulated following infection. The downregulated ATP5b also reduced ATP production in the murine macrophages infected with B. anthracis spores. Consequently, this study represents the first mitochondrial proteome analysis of infected macrophages.

Solandelactone G: A Novel Inhibitor of Farnesyl Protein Transferase (FPTase), Isolated from the Hydroid Solanderia secunda

  • Jongheon Shin;Youngwan Seo;Park, Jung-Rae;Kwon, Byoung-Mog;Nam, Ji-Youn;Jeong, Tae-Sook;Bok, Song-Hae
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1995.04a
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    • pp.63-63
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    • 1995
  • Farnesyl Protein Transferase (FPTase) catalyses a post-translational modification of Ras that is obligatory for the cell transforming activity of this oncogene protein. The screening of natural products to identify inhibitors of this enzyme as a potential anticancer agents, has led to the isolation of a novel lactone, from the hydroid Solanderia secunda. Solandelactone G has been isolated from the hydroid Solanderia secunda collected along the offshore of Jaejudo and Keomunde. The structure of the compound has been determined as cyclopropane containing C$\_$22/ fatty acid lactone on the basis of the combined spectral and chemical methods

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Isolation of Grb2-Shc Domain Binding Inhibition Component from Agastache rugosa (배초향으로부터 Grb2-Shc domain 결합저해 물질의 분리)

  • Lee, Eun-Sook;Ahn, Byung-Tae;Lee, Sae-Bom;Kim, Hyae-Kyeong;Bok, Song-Hae;Jeong, Tae-Sook
    • Korean Journal of Pharmacognosy
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    • v.30 no.4
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    • pp.404-408
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    • 1999
  • SH2 domains and their associated catalytic or noncatalytic proteins constitute critical signal transduction targets for drug discovery. Grb2 associates with phosphotyrosine sites of the activated receptors or Shc via their SH2 domain to link receptor tyrosine kinases to ras signalling. Blocking of the Grb2-Shc complex may be to intervene the oncogenic signal transduction pathways and to develop a new antitumor drug. In the search for blockers of Grb2 SH2-Shc interaction, Lutein, a family of carotenoids, was isolated from the extract of the leaf of Agastache rugosa O. Kuntze as SH2 domain antagonists. The $IC_{50}$ of Lutein against Grb2-Shc binding was $6.8\;{\mu}M$.

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