• Title/Summary/Keyword: Target response spectrum

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Signal Transduction Network Leading to COX-2 Induction: A Road Map in Search of Cancer Chemopreventives

  • Surh Young-Joon;Kundu Joydeb Kumar
    • Archives of Pharmacal Research
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    • v.28 no.1
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    • pp.1-15
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    • 2005
  • Cancer is still a major global health concern even after an everlasting strive in conquering this dread disease. Emphasis is now given to chemoprevention to reduce the risk of cancer and also to improve the quality of life among cancer afflicted individuals. Recent progress in molecular biology of cancer has identified key components of the cellular signaling network, whose functional abnormality results in undesired alterations in cellular homeostasis, creating a cellular microenvironment that favors premalignant and malignant transformation. Multiple lines of evidence suggest an elevated expression of cyclooxygenase-2 (COX-2) is causally linked to cancer. In response to oxidative/pro-inflammatory stimuli, turning on unusual signaling arrays mediated through diverse classes of kinases and transcription factors results in aberrant expression of COX-2. Population-based as well as laboratory studies have explored a broad spectrum of chemopreventive agents including selective COX-2 inhibitors and a wide variety of anti-inflammatory phytochemicals, which have been shown to target cellular signaling molecules as underlying mechanisms of chemoprevention. Thus, unraveling signaling pathways regulating aberrant COX-2 expression and targeted blocking of one or more components of those signal cascades may be exploited in searching chemopreventive agents in the future.

Development of the DGRS enriched in the high frequency range for APR1400 (고진등수 영역이 보강된 APR1400 설계지반응답스펙트럼의 개발)

  • 장영선;김태영;주광호;김종학
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2001.09a
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    • pp.67-74
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    • 2001
  • This paper presents the Safe Shutdown Earthquake(SSE) input motion for the seismic design of the Advanced Power Reactor 1400(APR1400). The Design Ground Response Spectra(DGRS) far the SSE is based on the design spectrum specified in regulatory Guide(RG) 1.60 of U.S. Nuclear Regulatory Commission(US NRC), anchored to a Peak Ground Acceleration(PGA) of 0.3g and enriched in the high frequency range. This SSE seismic input motion is to be applied to the seismic analysis as the free-field seismic motion at the ground surface of both the rock and generic soil sites fur APRI1400. The enrichment for APR1400 seismic input motion is performed considering the current US NRC regulations, the seismic hazard studies performed by the Lawrence Livermore National Laboratory (LINL) and Electric Power Research Institute(EPRI) for the Central and Eastern United States nuclear power plant sites, and the seismic input motions used in the design certifications of the three existing U.S. advanced standard plants. It is represented by a set of DGRS and the accompanying Target Power Spectral Density(PSD) Function in both the horizontal and vertical directions.

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Design for improving the impact resistance of a vehicle equipped with the circuit card assembly (비행체 탑재 회로카드 조립체의 내충격 향상을 위한 설계)

  • Lee, Chang-Min;Kang, Dong-Suk;Shin, Young-Hoon;Lee, Ki-Sun
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2014.10a
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    • pp.48-53
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    • 2014
  • Rocket, held using the CCA for the mission, a plurality of recording devices, and navigation equipment. In case of a projectile which is entered the water after fired into the air, after performing stages and fairing separated in flight to enter the underwater. It is caused by the explosion of gunpowder mainly, vibration phenomenon of a large transition is induced structurally very, also on entering the water, have a significant shock structurally separated. If shock is transmitted directly to the CCA through the body, it can be caused malfunction of payloads, resulting in failure of the mission of the projectile. In order to ensure the stability against shock, in this paper, Calculating a target resonacne frequency of the CCA, and verified through modal test and analysis. Maximum acceleration position of CCA is checked by SRS analysis. In addition, effectiveness of shock isolation system through shock analysis.

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Comparison of the seismic performance of existing RC buildings designed to different codes

  • Zeris, Christos A.;Repapis, Constantinos C.
    • Earthquakes and Structures
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    • v.14 no.6
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    • pp.505-523
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    • 2018
  • Static pushover analyses of typical existing reinforced concrete frames, designed according to the previous generations of design codes in Greece, have established these structures' inelastic characteristics, namely overstrength, global ductility capacity and available behaviour factor q, under planar response. These were compared with the corresponding demands at the collapse limit state target performance point. The building stock considered accounted for the typical variability, among different generations of constructed buildings in Greece, in the form, the seismic design code in effect and the material characteristics. These static pushover analyses are extended, in the present study, in the time history domain. Consequently, the static analysis predictions are compared with Incremental Dynamic Analysis results herein, using a large number of spectrum compatible recorded base excitations of recent destructive earthquakes in Greece and abroad, following, for comparison, similar conventional limiting failure criteria as before. It is shown that the buildings constructed in the 70s exhibit the least desirable behaviour, followed by the buildings constructed in the 60s. As the seismic codes evolved, there is a notable improvement for buildings of the 80s, when the seismic code introduced end member confinement and the requirement for a joint capacity criterion. Finally, buildings of the 90s, designed to modern codes exhibit an exceptionally good performance, as expected by the compliance of this code to currently enforced seismic provisions worldwide.

Behavior Analysis of a Seismically Isolated NPP Structure by Varying Seismic Input Generation Method and Strong Ground Motion Duration (입력운동 생성방법과 강진지속시간에 따른 면진원전의 거동 분석)

  • Kim, Hyun-Uk;Joo, Kwang-Ho;Noh, Sang-Hoon;Jung, Chang-Gyun
    • Journal of the Earthquake Engineering Society of Korea
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    • v.17 no.4
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    • pp.187-195
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    • 2013
  • In this paper, firstly, acceleration-time histories were generated by varying strong motion duration in the frequency domain for application to a seismically isolated nuclear power structure, so as to examine the effects of strong motion duration on the behavior of the structure. Secondly, real recorded earthquakes were modified to match the target response spectrum based on the revised SRP 3.7.1(2007) and the modified time histories were applied to the analysis of a seismically isolated nuclear power structure. The obtained values of acceleration and displacement responses of the structure were, finally, compared with the values obtained in case of applying acceleration-time histories generated in the frequency domain to the structure.

The MicroRNA-551a/MEF2C Axis Regulates the Survival and Sphere Formation of Cancer Cells in Response to 5-Fluorouracil

  • Kang, Hoin;Kim, Chongtae;Ji, Eunbyul;Ahn, Sojin;Jung, Myeongwoo;Hong, Youlim;Kim, WooK;Lee, Eun Kyung
    • Molecules and Cells
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    • v.42 no.2
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    • pp.175-182
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    • 2019
  • microRNAs regulate a diverse spectrum of cancer biology, including tumorigenesis, metastasis, stemness, and drug resistance. To investigate miRNA-mediated regulation of drug resistance, we characterized the resistant cell lines to 5-fluorouracil by inducing stable expression of miRNAs using lenti-miRNA library. Here, we demonstrate miR-551a as a novel factor regulating cell survival after 5-FU treatment. miR-551a-expressing cells (Hep3B-lenti-miR-551a) were resistant to 5-FU-induced cell death, and after 5-FU treatment, and showed significant increases in cell viability, cell survival, and sphere formation. It was further shown that myocyte-specific factor 2C is the direct target of miR-551a. Our results suggest that miR-551a plays a novel function in regulating 5-FU-induced cell death, and targeting miR-551a might be helpful to sensitize cells to anti-cancer drugs.

Identification and structure of AIMP2-DX2 for therapeutic perspectives

  • Hyeon Jin Kim;Mi Suk Jeong;Se Bok Jang
    • BMB Reports
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    • v.57 no.7
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    • pp.318-323
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    • 2024
  • Regulation of cell fate and lung cell differentiation is associated with Aminoacyl-tRNA synthetases (ARS)-interacting multifunctional protein 2 (AIMP2), which acts as a non-enzymatic component required for the multi-tRNA synthetase complex. In response to DNA damage, a component of AIMP2 separates from the multi-tRNA synthetase complex, binds to p53, and prevents its degradation by MDM2, inducing apoptosis. Additionally, AIMP2 reduces proliferation in TGF-β and Wnt pathways, while enhancing apoptotic signaling induced by tumor necrosis factor-α. Given the crucial role of these pathways in tumorigenesis, AIMP2 is expected to function as a broad-spectrum tumor suppressor. The full-length AIMP2 transcript consists of four exons, with a small section of the pre-mRNA undergoing alternative splicing to produce a variant (AIMP2-DX2) lacking the second exon. AIMP2-DX2 binds to FBP, TRAF2, and p53 similarly to AIMP2, but competes with AIMP2 for binding to these target proteins, thereby impairing its tumor-suppressive activity. AIMP2-DX2 is specifically expressed in a diverse range of cancer cells, including breast cancer, liver cancer, bone cancer, and stomach cancer. There is growing interest in AIMP2-DX2 as a promising biomarker for prognosis and diagnosis, with AIMP2-DX2 inhibition attracting significant interest as a potentially effective therapeutic approach for the treatment of lung, ovarian, prostate, and nasopharyngeal cancers.

Seismic Design of Buckling-Restrained Braced frame Using Equivalent Energy Concept (등가 에너지 개념을 이용한 비좌굴 가새골조의 내진설계)

  • 김진구;최현훈;원영섭
    • Journal of the Earthquake Engineering Society of Korea
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    • v.7 no.3
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    • pp.47-55
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    • 2003
  • This study proposed a convenient seismic design procedure for buckling-restrained braced frames based on the equivalent energy concept. The design process begins with the computation of input energy from response spectrum. Then the elastic energy and plastic energy are computed based on the equal energy concept. The computed plastic energy is distributed to each story along energy distribution ratio and the cross-sectional area of each brace is computed so that all the plastic energy is dissipated by the brace. The proposed procedure was applied to the design of three-, six-, and twenty-story steel frames with buckling-restrained braces, and artificial earthquake records were used for verification of the proposed method. According to analysis results, top story displacements of the low-rise structure satisfies the given target displacement however that of the twenty-story structure was much smaller than the given target displacement.

Modeling and Detent Torque Hormonic Analysis of Hybrid Type Step Motor (하이브리드형 스텝모터의 모델링 및 디텐트 토크 고조파 분석)

  • Yoon, Shin-Yong;Baek, Soo-Hyun;Kim, Yong;Kim, Cherl-Jin
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.16 no.5
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    • pp.14-21
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    • 2002
  • This paper did the study target for modeling, characteristics analysis and harmonic reduce with the detent torque of a 4 phase and 5 phase hybrid type step motor. For this, it was attempted to derive the mathematical modeling and used the permeance method for flux field analysis. Through this analysis result, this paper acquired the detent torque of this model. To compare the characteristics analysis of phase difference with two motors structure it have obtained to derive the operating detent torque with this model. Here, 5 phase motor has known the harmonic reduce of detail torque compare with 4 phase motor. Also, that has showed to improved the step response. The analysis result has represent the effect that a fundamental component of the permeance distribution produces the average torque and that harmonic components produce the ripple torque.

Effects of Significant Duration of Ground Motions on Seismic Responses of Base-Isolated Nuclear Power Plants (지진의 지속시간이 면진원전의 지진거동에 미치는 영향)

  • Nguyen, Duy-Duan;Thusa, Bidhek;Lee, Tae-Hyung
    • Journal of the Earthquake Engineering Society of Korea
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    • v.23 no.3
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    • pp.149-157
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    • 2019
  • The purpose of this study is to investigate the effects of the significant duration of ground motions on responses of base-isolated nuclear power plants (NPPs). Two sets of ground motion records with short duration (SD) and long duration (LD) motions, scaled to match the target response spectrum, are used to perform time-history analyses. The reactor containment building in the Advanced Power Reactor 1400 (APR1400) NPP is numerically modeled using lumped-mass stick elements in SAP2000. Seismic responses of the base-isolated NPP are monitored in forms of lateral displacements, shear forces, floor response spectra of the containment building, and hysteretic energy of the lead rubber bearing (LRB). Fragility curves for different limit states, which are defined based on the shear deformation of the base isolator, are developed. The numerical results reveal that the average seismic responses of base-isolated NPP under SD and LD motion sets were shown to be mostly identical. For PGA larger than 0.4g, the mean deformation of LRB for LD motions was bigger than that for SD ones due to a higher hysteretic energy of LRB produced in LD shakings. Under LD motions, median parameters of fragility functions for three limit states were reduced by 12% to 15% compared to that due to SD motions. This clearly indicates that it is important to select ground motions with both SD and LD proportionally in the seismic evaluation of NPP structures.