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The hidden switches undertying RORα-mediated circuits that critically regulate uncontrolled cell proliferation

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Journal of Molecular Cell Biology 2014年第4期8卷 338-348页

作者： Dongkwan Shin ik Soo kim Ji Min Lee sung-Young Shin Jong-Hoon Lee sung Hee Baek Kwang-Hyun Cho Department of Bio and Brain Engineering Korea Advanced Institute of Science and Technology (KAIST) Daejeon 305-701 Republic of Korea Department of Biological Sciences Creative Research Initiative Center for Chromatin Dynamics Seoul National University Seou1151-742 Republic of Korea

Prostaglandin E2 （PGE2） is known to have a key role in the development of colorectal cancer, but previous experiments showed its contrasting （i.e. tumor-promoting or tu mor-suppressive） roles depending on experimental conditions. To elucidate the mechanisms underlying such contrasting roles of PG E2 in tumorigenesis, we investigated all the previous experiments and found a new signal transduction pathway mediated by retinoic acid receptor-related orphan receptor （ROR）α, in which PGE2/PKCα-dependent phosphorylation of RORα attenuates Wnt target gene expression in colon cancer ceils. From mathematical simulations combined with biochemical experimentation, we revealed that RORα induces a biphasic response of Wnt target genes to PGE2 stimulation through a regulatory switch formed by an incoherent feedforward loop, which provides a mechanistic explanation on the contrasting roles of PGE2 observed in previous experiments. More interestingly, we found that RORα constitutes another regulatory switch formed by coupled positive and negative feedback loops, which regulates the hysteretic response of Wnt signaling and eventually converts a proliferative cellular state into an anti-proliferative state in a very delicate way. Our results indicate that RORα is the key regulator at the center of these hidden switches that critically regulate cancer celt proliferation and thereby being a promising anti-cancer therapeutic target.

关键词： colorectal cancer Wnt signaling RORα mathematical modeling biphasic response hysteresis systems biology

Die Casting Mold Design of the Thin-walled Aluminum Case by Computational Solidification Simulation

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Journal of Materials Science & Technology 2008年第3期24卷 383-388页

作者： Young-Chan kim Chang-Seog Kang Jae-ik Cho Chang-Yeol Jeong Se-Weon Choi sung-Kil Hong Korea Institute of Industrial Technology Chonnam National University

Recently, demand for the lightweight alloy in electric/electronic housings has been greatly increased. However, among the lightweight alloys, aluminum alloy thin-walled die casting is problematic because it is quite difficult to achieve sufficient fluidity and feedability to fill the thin cavity as the wall thickness becomes less than 1mm. Therefore, in this study, thin-walled die casting of aluminum （Al-Si-Cu alloy： ALDC 12） in size of notebook computer housing and thickness of 0.8 mm was investigated by solidification simulation （MAGMA soft） and actual casting experiment （Buhler Evolution B 53D）. Three different types of gating design, finger, tangential and split type with 6 vertical runners, were simulated and the results showed that sound thin-walled die casting was possible with tangential and split type gating design because those gates allowed aluminum melt to flow into the thin cavity uniformly and split type gating system was preferable gating design comparing to tangential type gating system at the point of view of soundness of casting and distortion generated after solidification. Also, the solidification simulation agreed well with the actual die-casting and the casting showed no casting defects and distortion.

关键词： Aluminum casting alloy Thin-wall die casting Solidification simulation

Profile of Blow-up Solution to Hyperbolic System with Nonlocal Term

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Acta Mathematica Sinica,English Series 2007年第6期23卷 1083-1094页

作者： Zhi Wen DUAN Kwang ik kim Department of Mathematics Huazhong University of Science and Technology Wuhan 430074 P. R. China Department of Mathematics Pohang University of Science and Technology Pohang 790-784 Republic of Korea

This paper is concerned with a nonlocal hyperbolic system as follows utt = △u ＋（∫Ωvdx ）^p for x∈R^N,t〉0 ,utt = △u ＋（∫Ωvdx ）^q for x∈R^N,t〉0 ,u（x,0）=u0（x）,ut（x,0）=u01（x） for x∈R^N,u（x,0）=u0（x）,ut（x,0）=u01（x） for x∈R^N, where 1≤ N ≤3, p ≥1, q ≥ 1 and pq 〉 1. Here the initial values are compactly supported and Ω belong to R^N is a bounded open region. The blow-up curve, blow-up rate and profile of the solution are discussed.

关键词： hyperbolic system nonlocal term blow-up profile

Energy Estimate for the Type-Ⅱ Superconducting Film

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Acta Mathematica Sinica,English Series 2008年第1期24卷 75-86页

作者： Kwang ik kim Zu Han LIU Department of Mathematics Pohang University of Science and Technology Pohang 790-784 Republic of Korea Department of Mathematics Xuzhou Normal University Xuzhou 221116 P. R. China

We study the minimizers of the Ginzburg-Landau model for variable thickness, superconducting, thin films with high k, placed in an applied magnetic field hex, when hex is of the order of the ＂first critical field＂, i.e. of the order of ｜lnε｜. We obtain the asymptotic estimates of minimal energy and describe the possible locations of the vortices.

关键词： superconductivity Ginzburg-Landau functional free boundary problem

Inversion of two-phase extensional basin systems during subduction of the Paleo-Pacific Plate in the SW Korean Peninsula:Implication for the Mesozoic “Laramide-style” orogeny along East Asian continental margin

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Geoscience Frontiers 2019年第3期10卷 909-925页

作者： Seung-ik Park Jungrae Noh Hee Jun Cheong Sanghoon Kwon Yungoo Song sung Won kim M.Santosh Department of Geology Kyungpook National University Department of Earth System Sciences Yonsei University School of Earth Sciences The Ohio State University Geology Division Korea Institute of Geoscience and Mineral Resources School of Earth Sciences and Resources China University of Geosciences Department of Earth Sciences University of Adelaide

During subduction, continental margins experience shortening along with inversion of extensional sedimentary basins. Here we explore a tectonic scenario for the inversion of two-phase extensional basin systems, where the Early-Middle Jurassic intra-arc volcano-sedimentary Oseosan Volcanic Complex was developed on top of the Late Triassic-Early Jurassic post-collisional sequences, namely the Chungnam Basin. The basin shortening was accommodated mostly by contractional faults and related folds. In the basement, regional high-angle reverse faults as well as low-angle thrusts accommodate the overall shortening, and are compatible with those preserved in the cover. This suggests that their spatial and temporal development is strongly dependent on the initial basin geometry and inherited *** in transport direction observed along the basement-sedimentary cover interface is a characteristic structural feature, reflecting sequential kinematic evolution during basin inversion. Propagation of basement faults also enhanced shortening of the overlying sedimentary cover sequences. We constrain timing of the Late Jurassic-Early Cretaceous(ca. 158-110 Ma) inversion from altered K-feldspar 40 Ar/39 Ar ages in stacked thrust sheets and K-Ar illite ages of fault gouges, along with previously reported geochronological data from the area. This "non-magmatic phase" of the Daebo Orogeny is contemporaneous with the timing of magmatic quiescence across the Korean Peninsula. We propose the role of flat/low-angle subduction of the Paleo-Pacific Plate for the development of the "Laramide-style" basement-involved orogenic event along East Asian continental margin.

关键词： Two-phase extensional basin systems Paleo-Pacific Plate Inversion tectonics “Laramide-style” orogeny East Asian continental margin

Paleozoic tectonic evolution of the proto-Korean Peninsula along the East Asian continental margin from detrital zircon U-Pb geochronology and Hf isotope geochemistry

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Geoscience Frontiers 2024年第1期15卷 97-117页

作者： Yirang Jang sung Won kim Vinod O.Samuel Sanghoon Kwon Seung-ik Park M.Santosh Keewook Yi Department of Earth and Environmental Sciences Chonnam National UniversityGwangju 61186Republic of Korea Geology Division Korea Institute of Geoscience and Mineral ResourcesDaejeon 34132Republic of Korea Department of Earth System Sciences Yonsei UniversitySeoul 03722Republic of Korea Department of Geology Kyungpook National UniversityDaegu 41566Republic of Korea School of Earth Sciences and Resources China University of Geosciences BeijingBeijing 100083China Department of Earth Science University of AdelaideAdelaide SA 5005Australia Yonsei Frontiers Lab Yonsei UniversitySeoul 03722Republic of Korea Division of Earth and Environmental Sciences Korea Basic Science InstituteChungbuk 28119Republic of Korea

Detrital zircon geochronology and Hf isotope analysis can be used for inferring provenance characteristics,and to evaluate the tectonic evolution of sedimentary basins and their link with regional *** Paleozoic sequences of the Okcheon Belt consist of the Lower Paleozoic Joseon and the Upper Paleozoic Pyeongan supergroups with Middle Paleozoic hiatus locally on top of the Neoproterozoic bimodal volcanic rocks,reflecting an intracontinental rift setting between the two basements(*** and Yeongnam massifs)at southern part of the Korean *** detrital zircon U-Pb ages and Lu-Hf isotope results show that all these Paleozoic strata commonly have Paleoproterozoic and Paleozoic zircon ages with rare Meso-to Neoproterozoic *** individual zircon populations display following features,allowing estimation of their sedimentary provenances:(i)The Paleoproterozoic zircons(ca.1.85 Ga and 2.50 Ga)with similar ranges ofεHf(t)values are most common in the basement rocks of the Korean Peninsula,and were sourced from both the Gyeonggi and Yeongnam massifs.(ii)The Meso-to Neoproterozoic zircons,preserved only in the Middle to Late Cambrian clastic sedimentary rocks within the carbonate sequences probably reflect proximal provenance.(iii)The youngest Paleozoic zircons of each formation,almost coincident with their deposition ages,suggest presence of syndepositional magmatism,indicating proximal magmatic sources during their deposition.(iv)The Cambrian-Ordovician zircons,from the Lower Paleozoic sequences,but rare in the successive Upper Paleozoic sequences,suggest a provenance change after the hiatus between the two sedimentary successions.(v)The Permian zircons showing differentεHf(t)values indicate that detrital sources were varied at that *** integrated results in our study suggest provenance variability linked to diverse tectonic environments,reflecting prolonged subduction-related crustal evolution of the proto-Korean Peninsula during the Paleozo

关键词： Detrital zircon U-Pb and Hf isotopes Paleozoic metasedimentary rocks Okcheon Belt Taebaeksan zone Korean Peninsula

Carbon nanotube formation using zeolite template and applications

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Journal of Advanced Ceramics 2012年第3期1卷 179-193页

作者： Wei ZHAO Bijay BASNET ik Jin kim Institute for Processing and Application of Inorganic Materials(PAIM) Department of Materials Science and EngineeringHanseo UniversitySeosan city 356-706Korea

Carbon nanotubes(CNTs)have attracted intensive interests of researchers for a long time due to their fascinating physical and chemical properties promising for various potential applications,including advanced ceramics,nanoelectronic devices,nanoscale sensors,solar cells,battery electrode,field emitters,etc..This review summarized the synthetic methods of CNTs,with an emphasis on the chemical vapor deposition(CVD)method,especially catalytic *** there still are some challenges in the way,with the development of the technology,a hope for widespread applications always exists.

关键词： carbon nanotubes catalytic chemical vapor deposition zeolite template catalyst

Our works on conservation of wooden objects in Korea

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江汉考古 2014年第S1期 33-38页

作者： kim ik Joo

韩国木质文物的系统保护始于1976年新安沉船出土后,新安沉船保护方法的研究促进了饱水木保护技术的发展,是韩国木质文物保护的转折点,为木质文物保护新方法、新技术的研究搭建了一个平台。二十世纪九十年代以后韩国出土了大量木质文物,... 详细信息

韩国木质文物的系统保护始于1976年新安沉船出土后,新安沉船保护方法的研究促进了饱水木保护技术的发展,是韩国木质文物保护的转折点,为木质文物保护新方法、新技术的研究搭建了一个平台。二十世纪九十年代以后韩国出土了大量木质文物,这些文物的出土提供了很多新信息,是重要的历史资源。这一趋势促使了韩国保护工作人员对木质文物保护新方的研究。韩国的木质文物实际上是埋藏在沼泽、湖底和海底的饱水木,这些环境限制了微生物的生长。遗址中出土的木质器物是糟朽木或是碳化木。因此,韩国木质文物的保护分两类:一类是用传统工艺修复木建筑和漆器,另一类是保护处理饱水木器。文中介绍了韩国文物保护实验室保护修复木质文物的几个实例。

关键词： Our works on conservation of wooden objects in Korea

Mechanically resilient,alumina-reinforced carbon nanotube arrays for in-plane shock absorption in micromechanical devices

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Microsystems & Nanoengineering 2023年第3期9卷 73-81页

作者： Eunhwan Jo Hojoon Lee Jae-ik Lee Jongbaeg kim School of Mechanical Engineering Yonsei University50 Yonsei-roSeodaemun-guSeoul 03722Republic of Korea Department of Neurosurgery Massachusetts General HospitalHarvard Medical School25 Shattuck StBostonMA 02115USA

Microelectromechanical systems(MEMS)are of considerable interest due to their compact size and low power consumption when used in modern *** devices intrinsically incorporate three-dimensional(3D)microstructures for their intended operations;however,these microstructures are easily broken by mechanical shocks accompanying high-magnitude transient acceleration,inducing device *** various structural designs and materials have been proposed to overcome this limit,developing a shock absorber for easy integration into existing MEMS structures that effectively dissipates impact energy remains ***,a vertically aligned 3D nanocomposite based on ceramic-reinforced carbon nanotube(CNT)arrays is presented for in-plane shock-absorbing and energy dissipation around MEMS *** geometrically aligned composite consists of regionally-selective integrated CNT arrays and a subsequent atomically thick alumina layer coating,which serve as structural and reinforcing materials,*** nanocomposite is integrated with the microstructure through a batch-fabrication process and remarkably improves the in-plane shock reliability of a designed movable structure over a wide acceleration range(0-12,000g).In addition,the enhanced shock reliability through the nanocomposite was experimentally verified through comparison with various control devices.

关键词： shock plane arrays