• 제목/요약/키워드: forced migration

검색결과 31건 처리시간 0.021초

Cellular Changes Resulting from Forced Expression of Glypican-3 in Hepatocellular Carcinoma Cells

  • Kwack, Mi Hee;Choi, Byung Yeol;Sung, Young Kwan
    • Molecules and Cells
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    • 제21권2호
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    • pp.224-228
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    • 2006
  • Glypican-3 (GPC3) is a member of the glypican family, which encodes cell-surface heparan-sulfate proteoglycans, and is frequently upregulated in hepatocellular carcinoma (HCC). We have recently reported that blocking endogenous GPC3 expression promotes the growth of HCC cell lines, suggesting that GPC3 plays a negative role in HCC cell proliferation. Here, we report that forced expression of GPC3 reduced the growth of HCC cells. We also found that FGF2-mediated cell proliferation was inhibited by GPC3. In addition, we observed that the adhesion of HCC cells to collagen type I and fibronectin was decreased by GPC3, whereas cellular migration and invasiveness were stimulated. Collectively, these results suggest that progression of hepatocellular carcinoma is associated with upregulation of GPC3.

Droplet transient migration and dynamic force balance mechanism on vibration-controlled micro-texture surfaces

  • Xu, Jing;Liu, Guodong;Lian, Jiadi;Ni, Jing;Xiao, Jing
    • Current Applied Physics
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    • 제18권11호
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    • pp.1368-1374
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    • 2018
  • In this paper, forced vibration was used to regulate the droplet migration, fully recording the transient migration of droplets on a micro-textured substrate under the resonance frequency by a high-speed camera. The influence of resonance frequency and dynamic migration characteristics of droplets on the solid micro-texture surface under lateral vibration were researched. The experiment demonstrates that the driving force is caused by the difference between the left and right contact angles made the droplet oscillate and migrate, and as time t increases, the left and right contact points are periodically shifted and the amplitude of migration increases. Therefore, based on the droplet migration behavior and its force balance mechanism, a spring vibration model of migration behavior of the vibrating droplet micro unit was set up to predict the complete trajectory of its migration on a solid surface. The calculation results show that the theoretical displacement is less than the experimental displacement, and the longer the time, the larger the difference. Affected by the vibration, part of the droplet permeates through the micro-texture, resulting in the droplet losing height and the contact angle becoming smaller as well. While the other part of droplet overcomes the internal surface tension to migrate.

The Effect of Transverse Vibration on Red Blood Cell Aggregation and Blood Viscosity

  • Shin, Se-Hyun;Ku, Yun-Hee;Park, Myung-Su;Suh, Jang-Soo
    • International Journal of Vascular Biomedical Engineering
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    • 제1권2호
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    • pp.4-12
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    • 2003
  • The present study investigated the effect of transverse vibration on the hemorheological characteristics of blood using a newly designed pressure-scanning capillary viscometer. As vibration was applied, aggregated blood cells (rouleaux) were disaggregated. The range of vibration frequency and amplitude are $0{\sim}100\;Hz$ and $0{\sim}0.8\;mm$, respectively for a capillary diameter 0.84 mm. As vibration increased, blood viscosity initially increased and tended to decrease. In order to delineate the unexpected results, the present study proposed two counteracting mechanisms of vibration related with red blood cell (RBC) aggregation affecting hemo-rheological properties. One is the reduction of RBC aggregation due to vibration causing an increase of blood viscosity. The other is forced cell migration due to the transverse vibration, which in turn forms a cell-free layer near the tube wall and causes a decrease of flow resistance.

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RESIN TRANSFER MOLDING 공정에서의 기공 형성에 관한 3차원 모델링 (Three-Dimensional Modeling of Void Formation During Resin Transfer Molding)

  • 배준호;강문구;임성택;이우일
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2001년도 춘계학술대회논문집C
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    • pp.246-250
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    • 2001
  • In resin transfer molding (RTM), resin is forced to flow through the fiber perform of inhomogeneous permeability. This inhomogeneity is responsible for the mismatch of resin velocity within and between the fiber tows. The capillary pressure of the fiber tows exacerbates the spatial variation of the resin velocity. The resulting microscopic perturbations of resin velocity at the flow front allow numerous air voids to form. In this study, a mathematical model was developed to predict the formation and migration of micro-voids during resin transfer molding. A transport equation was employed to account for the migration of voids between fiber tows. Incorporating the proposed model into a resin flow simulator, the volumetric content of micro-voids in the preform could be obtained during the simulation of resin impregnation.

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AOP를 이용한 이동 에이전트의 투명한 이주 기법 설계 (Transparent Migration Scheme of Mobile Agent by using AOP)

  • 임원택;김구수;엄영익
    • 한국정보처리학회:학술대회논문집
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    • 한국정보처리학회 2006년도 추계학술발표대회
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    • pp.551-554
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    • 2006
  • Java 기반의 이동 에이전트 시스템은 에이전트의 실행 상태를 이주시킬 수 없는 문제점을 가지고 있다. 이러한 문제점을 해결하기 위해 JVM을 수정하거나 이주에 필요한 소스 코드, 혹은 바이트 코드를 삽입하는 메커니즘을 이용한 이동 에이전트 시스템들이 연구되었다. 하지만 이러한 시스템들은 이식성이 떨어지거나 에이전트의 이주부분을 프로그래밍 할 수 없는 단점이 존재한다. 또한 이러한 시스템들은 플랫폼의 요청에 의한 에이전트 이주 기법인 forced migration을 지원하지 않는다. 본 논문에서는 AOP(Aspect Oriented Programming)를 이용한 에이전트의 투명한 이주 기법을 제안한다. 제안 기법에서는 에이전트를 비즈니스 로직, 이동성 코드, 상태 저장 코드로 나누어 개발하고, 이를 직조하여 이동 에이전트를 개발한다. 제안 기법을 사용하면 에이전트 개발자는 이동 에이전트의 비즈니스 로직 개발에 집중할 수 있고 에이전트의 이주 부분을 프로그래밍 함으로써, 유연한 에이전트의 이주 정책을 수립할 수 있다.

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주기적인 하폭 변화 수로에서 사주의 거동에 관한 수치실험 (Numerical Experiments of the Behavior of Bars in the Channels with Periodic Variable Width)

  • 장창래
    • 한국수자원학회논문집
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    • 제47권1호
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    • pp.37-47
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    • 2014
  • 본 연구에서는 하폭의 주기적인 변화에 의하여 교호사주와 복렬사주가 발생하는 수리학적 조건에서 주기적인 하폭변화에 의한 강제사주의 형성과정과 거동 특성을 2차원 수치모형을 이용하여 파악하였다. 하폭변화의 진폭이 크면, 사주의 파장은 짧아지고, 사주의 이동성은 크게 감소하였다. 교호사주가 발생할 수 있는 영역에서는 하폭의 변화에 대하여 강제효과가 크게 작용하며, 복렬사주가 발생할 영역에서는 하폭의 변화에 의한 강제효과가 상대적으로 작은 특성을 보여주었다. 복렬사주가 발달한 조건에서는 하도변화의 진폭 대 평균하폭의 비인 무차원 진폭이 0.25로 증가할 때 사주의 이동속도는 증가하지만, 이보다 크면 사주의 이동속도가 급격하게 감소하였다. 교호사주가 발생하는 조건에서는 사주의 파장 대하폭 변화의 파장 비인 무차원 사주의 파장이 증가할수록 사주의 이동속도가 증가하지만, 무차원 사주의 파장이 1에 가까운 경우에 사주의 이동속도가 급격하게 감소하였다. 즉, 사주의 파장과 하폭의 파장이 일치할 때, 하폭변화에 의한 강제효과가 강하게 작용하여 사주가 압박되기 때문이다.

중국 조선족 디아스포라의 지리적 해석: 중국 동북3성 조선족 이주를 중심으로 (Geographical Interpretation of Korean Diaspora in Northeastern China: Its Migration and Spatial Diffusion)

  • 최재헌;김숙진
    • 대한지리학회지
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    • 제51권1호
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    • pp.167-184
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    • 2016
  • 본 논문은 중국 조선족의 이주과정을 시기별로 해석하고 각 시기에 따른 이주공간의 변화를 조선족 인구분포의 변화를 통해 밝히려고 하였다. 중국 조선족의 이주는 19세기 말부터 본격적으로 일어났으며, 1910년까지의 난민 월경기, 1930년까지의 정치 이주기, 1945년까지의 강제 이주기, 그리고 해방이후 최근까지의 경제 이주기로 나누어 그 특징을 고찰할 수 있다. 1910년대와 1930년대, 2000년대의 변화과정을 고찰하면 중국 조선족의 이주는 벼농사의 재배와 밀접한 관련이 있으며 초기에는 국경 인근에 벼농사가 유리한 지역으로 우선 이주가 시작되어 그 주변으로 조선족 취락이 확대되는 접촉확산으로, 1930년대 강제이주에 따라 철도를 따라 집단촌이 건설되고 2000년 이후 연해도시를 중심으로 집적지가 확대되는 계층확산으로 해석이 가능하다. 중국 조선족의 디아스포라 공간은 초기에 형성된 인구밀집지에서 지속적으로 인구가 증가하고 안정적으로 유지되었으나, 최근 농촌공동체에서 도시공동체로 변화하고 동북3성 위주의 단일지역 분포 패턴에서 연해 대도시와 해외이주가 포함된 다지역 분포 패턴으로 변화하고 있다.

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miR-124 Inhibits Growth and Invasion of Gastric Cancer by Targeting ROCK1

  • Hu, Cong-Bing;Li, Qiao-Lin;Hu, Jian-Fei;Zhang, Qiang;Xie, Jian-Ping;Deng, Li
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권16호
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    • pp.6543-6546
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    • 2014
  • MicroRNAs (miRNAs) act as critical regulators of genes involved in many biological processes. Aberrant alteration of miRNAs have been found in many cancers, including gastric cancer (GC), but the molecular mechanisms are not well understood. Herein, we investigated the role of miR-124 in GC. We found that its expression was significantly reduced in both GC tissue samples and cell lines. Forced expression of miR-124 suppressed GC cell proliferation, migration, and invasion. Furthermore, the Rho-associated protein kinase (ROCK1) was identified as a direct target of miR-124 in GC cells. Finally, silencing of ROCK1 showed similar effects as miR-124 overexpression, while supplementation of ROCK1 remarkably restored the cell growth and invasion inhibited by miR-124. Together, our data demonstrate that miR-124 acts as a tumor suppressor by targeting ROCK1, and posit miR-124 as a novel strategy for GC treatment.

사할린 영주귀국 동포의 주거생활사 - 안산시 고향마을 거주 강제이주 동포를 중심으로 - (Housing History of Sakhalin Returnees in Ansan Gohyangmaeul)

  • 조재순
    • 한국주거학회논문집
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    • 제20권4호
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    • pp.103-112
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    • 2009
  • The purpose of this research was to find out the housing history of Sakhalin returnees in Ansan Gohyangmaeul since leaving hometown under the Japanese ruling period, who experienced two international migration for one's life. Face to face interview had been done with 20 returnees in the community center of Ansan Gohyangmaeul during October to December, 2008. The semi-structured questionnaire about housing the respondents lived in major life changes used to guide the individual interview. The results showed that personal life as well as housing histories were differed by the reason to move into Sakhalin, which still influenced the returnee' life up to now. The housing they had lived changed from barracks like a training camp, to Japanese small wooden cottage/row house, and then Russian brick house/ apartment. Housing alteration and addition and rebuilding were common to renew the old existing house. The boundary of residing area was mostly limited to the first residing location under soviet governing system throughout one's life without a long distance move. Housing satisfaction was very high in Gohyangmaeul because of the improvement of housing facilities and residence itself as well as the convenience of housing management, compared to former residence in Sakhalin. Economic and emotional aspects of life satisfaction were also high during about 8 years of living in the apartment. Forced movers still require the compensation on hand to either Korean or Japanese government no matter the amount. Social integration to the Korean community would be one of the main issues to new returnees as well as the already returned. In-depth interviews of case study need to reveal the unique housing experience of the forced mover according to the type of leaving hometown by oneself or by parents, and to returned region and time to motherland.

입방형 채널 캐비티 유동의 PIV 해석 (PIV Analysis of Cubic Channel Cavity Flow)

  • 조대환;김진구;이영호
    • Journal of Advanced Marine Engineering and Technology
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    • 제21권5호
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    • pp.557-563
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    • 1997
  • The unsteady flow in three-dimensional cubic cavity with narrow channel at upper region is investigated experimentally for three kinds of Reynolds number, 1*10/sup 4/, 3*10/sup 4/ and 5*10/sup 4/ based on the cavity width and cavity inlet mean flow velocity. Instant velocity vectors are obtained simultaneously at whole field by PIV(Particle Image Velocimetry). Wall pressure distributions are estimated using Poisson equation from the velocity data. Results of PIV reveal that severe unsteady flow fluctuation within the cavity are remarkable at all Reynolds numbers and sheared mixing layer phenomena are also found at the region where inlet driving flow is collided with the clock-wise rotating main primary vortex. Instant velocity profiles reveal that deformed forced vortex formation is observed throughout the entire region and spanwise kinetic energy migration is conspicuous.

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