• 제목/요약/키워드: migration study

검색결과 2,248건 처리시간 0.034초

제지용 형광증백제의 전이현상에 대한 기초연구 (Study on the Migration of Fluorescent Whitening Agents Used for Papermaking Process)

  • 이지영;김철환;성용주;김은혜;김재형;박태웅
    • 펄프종이기술
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    • 제48권3호
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    • pp.5-13
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    • 2016
  • This study investigated the effects of different factors on the migration of a fluorescent whitening agent (FWA) from paper treated with FWAs to non-fluorescent papers. FWA migration experiments were carried out in vertical and friction contacts between the papers dyed with FWAs and non-fluorescent papers. During the experiments, we identified the effects of the addition and types of FWAs, contact time, temperature, and relative humidity (RH) on FWA migration. The fluorescence indices of the non-fluorescent papers were measured before and after the migration experiments, and the Student's t test, a statistical tool, was utilized to compare results from different migration experiments. In vertical contact experiments, FWA migration to non-fluorescent paper was observed at $30^{\circ}C$ and 70% RH; this was attributed to the high moisture content of the paper. FWA migration did not occur significantly at $23^{\circ}C$ and 50% RH. In the friction contact experiments, FWA migrations were identified at both temperature conditions and RH percentages. The addition and types of FWAs did not increase the fluorescence index of non-fluorescent papers. Therefore, it was concluded that the moisture content of paper and the friction contact affected FWA migration from the papers containing internal and surface FWAs.

부산 대도시권의 인구이동( I ) : 인구구조와 인구이동 (Patterns of Migration in the Busan Metropolitan Area( I ) : Population Structure and Migration)

  • 최은영;구동회;박영실
    • 한국지역지리학회지
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    • 제15권5호
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    • pp.572-589
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    • 2009
  • 본 연구에서는 부산 대도시권의 인구이동 특성을 살펴보기 위하여 부산 대도시권의 인구구조, 부산 대도시권 내부의 인구이동, 부산 대도시권과 다른 지역 사이의 인구이동을 분석하였다. 주요 결과는 다음과 같다. 첫째, 전국 대비 부산 대도시권의 인구 및 가구 비율은 지속적으로 감소하고 있다. 특히 주 생산 연령층인 25~39세 인구가 크게 감소하였다. 둘째, 서울 대도시권에 비해 부산 대도시권은 상대적으로 시도내 인구이동 비율이 높고, 시도간 인구이동 비율이 낮은 것으로 보아, 기능적 연계에 의한 대도시권의 통합 정도가 낮은 것으로 판단된다. 셋째, 부산에서 서울 대도시권으로의 전출 초과가 갈수록 증가하여 부산의 전출 초과에서 수도권의 영향력이 강화되고 있다.

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Involvement of PI3K and MMP1 in PDGF-induced Migration of Human Adipose-derived Stem Cells

  • Lim, Yoonhwa;Lee, Minji;Jeong, Hyeju;Kim, Haekwon
    • 한국발생생물학회지:발생과생식
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    • 제21권2호
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    • pp.167-180
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    • 2017
  • Human adult stem cells have widely been examined for their clinical application including their wound healing effect in vivo. To function as therapeutic cells, however, cells must represent the ability of directed migration in response to signals. This study aimed to investigate the mechanism of platelet-derived growth factor (PDGF)-induced migration of the human abdominal adipose-derived stem cells (hADSCs) in vitro. A general matrix metalloproteinase (MMP) inhibitor or a MMP2 inhibitor significantly inhibited the PDGF-induced migration. PDGF treatment exhibited greater mRNA level and denser protein level of MMP1. The conditioned medium of PDGF-treated cells showed a caseinolytic activity of MMP1. Transfection of cells with siRNA against MMP1 significantly inhibited MMP1 expression, its caseinolytic activity, and cell migration following PDGF treatment. Phosphatidylinositol 3-kinase (PI3K) inhibitor reduced the migration by about 50% without affecting ERK and MLC proteins. Rho-associated protein kinase inhibitor mostly abolished the migration and MLC proteins. The results suggest that PDGF might signal hADSCs through PI3K, and MMP1 activity could play an important role in this PDGF-induced migration in vitro.

Role of Non-Thermal DBD Plasma on Cell Migration and Cell Proliferation in Wound Healing

  • Ali, Anser;Lee, Seung Hyun;Kim, Yong Hee;Uhm, Han Sup;Choi, Eun Ha;Park, Bong Joo
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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    • pp.526-526
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    • 2013
  • Plasma technology isbeing developed for a range of medical applications including wound healing. However, the effect of plasma on many cells and tissues is unclear. Cell migration and cell proliferation are very important biological processes which are affected by plasma exposure and might be a potential target for plasma therapy during wound healing treatment. In this study, we confirmed the plasma exposure time and incubation time after plasma treatment in skin fibroblast (L-929 cells) to evaluate the optimal conditions forplasma exposure to the cell in-vitro. In addition, we used a scratch method to generate artificial wound for evaluating the cell migration by plasma treatment. Where, the cells were treated with plasma and migration rate was observed by live-cell imaging device. To find the cell proliferation, cell viability assay was executed. The results of this study indicate the increased cell proliferation and migration on mild plasma treatment. The mechanisms for cell migration and cell proliferation after plasma treatment for future studies will be discussed.

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The Environmental Justice in Ecological Immigration A Case Study of Sanjiangyuan Area

  • Ma, Shuang;Ma, Sa
    • Architectural research
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    • 제17권4호
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    • pp.147-152
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    • 2015
  • Recently, there is an increasing criticism both inside and outside China toward the eco-migration projects. The author focuses on the eco-migration of Sanjiangyuan National Nature Reserve as a case study as it is one of the main eco-migration projects. At the end of 2010, government invested 4.47 billion CNY in eco-migration and relocated the immigration 55773 people in 10733 units. Benefits of eco-migration is obvious, however, it needs to be recognized that in the aspect of environment justice, it is unfair to sacrifice a group of people in the process of environmental protection because costs and benefits result from the environmental protection have to share among the people without discrimination. Local herdsmen received extra disadvantages in their level of material possessions, social and cultural values and the social inclusion after eco-migration project. As a part of the eco-social system established within several centuries, the local herdsmen are not only threateners to local ecology system, but also the guardians to the natural environment through religion and habits last for generations. The social and cultural values, traditional religion and Nomadic living habits, as important as the environment, are need to be cherished and protected.

금속 마이그레이션에 의한 화재 위험성 연구 (A Study on Fire Hazard by Metallic Migration)

  • 최경원;현병수;김선재;임규영;우승우;이동규;조영진;박종택;고재모;박남규
    • 한국화재소방학회논문지
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    • 제33권6호
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    • pp.114-119
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    • 2019
  • 우리는 LED등기구의 Printed circuit board (PCB)에서 화재의 원인으로 특정할 수 있는 금속 마이그레이션(Metallic migration) 현상을 발견하고, 본 연구를 진행하였다. 금속 마이그레이션 현상 가속화 실험인 물방울 시험을 소량의 물과 저전압(3 V)로 진행하고 절연되어있는 양극에서 직접적으로 금속 마이그레이션의 성장과 회로의 단락을 확인하였다. 그리고 전자주사현미경(SEM)을 통해 형태를 관찰하고 에너지 분산형 분광기(EDS)를 이용하여 성분을 분석한 결과, 절연된 부분에서 전극을 이루고 있는 구리의 성분을 검출하였다.

TRAIL Suppresses Human Breast Cancer Cell Migration via MADD/CXCR7

  • Wang, Rui;Li, Jin-Cheng
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권7호
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    • pp.2751-2756
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    • 2015
  • Background: Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) can specifically induce apoptosis limited to various cancer cells, so this reagent is considered a promising medicine for cancer therapy. TRAIL also exerts effects on non-apoptotic signals, relevant to processes such as metastasis, autophagy and proliferation in cancer cells. However, the mechanisms of TRAIL-regulated non-apoptotic signals are unclear. The purpose of this study was to investigate MADD/CXCR7 effects in TRAIL-mediated breast cancer cell migration. Materials and Methods: The ability of MADD/CXCR7 to regulate MVP signaling in TRAIL-mediated breast cancer cells migration was evaluated by transwell migration assay, quantitative RT-PCR, Western blotting and knock down experiments. Results: In this study, we found that treatment with TRAIL resulted in induced expression levels of MADD and CXCR7 in breast cancer cells. Knock down of MADD followed by treatment with TRAIL resulted in increased cell migration compared to either treatment alone. Similarly, through overexpression and knockdown experiments, we demonstrated that CXCR7 also positively regulated TRAIL-inhibited migration. Surprisingly, knock down of MADD lead to inhibition of TRAIL-induced CXCR7 mRNA and protein expression and overexpression of CXCR7 lead to the reduction of MADD expression, indicating that MADD is an upstream regulatory factor of TRAIL-triggered CXCR7 production and a negative feedback mechanism between MADD and CXCR7. Furthermore, we showed that CXCR7 is involved in MADD-inhibited migration in breast cancer cells. Conclusions: Our work defined a novel signaling pathway implicated in the control of breast cancer migration.

보두산의 금속분해효소 활성 저해를 통한 사람 대동맥 평활근세포의 유주능 억제 효과 (Inhibitory Effect of Bodusan on $TNF-{\alpha}-induced$ Migration via Inhibition of Metalloproteinase Activity in Human Aortic Smooth Muscle Cells)

  • 윤현정;박선동
    • 대한본초학회지
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    • 제23권3호
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    • pp.155-162
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    • 2008
  • Objectives : This study was evaluated to elucidate the inhibitory potential of Bodusan (BDS) and its components, Strychnos ignatii semen (SIS) and Glycyrrhizae Radix (GR), on human aortic smooth muscle cells (HASMC) migration and production of matrix metalloproteinase (MMP)-2 and MMP-9 by $TNF-{\alpha}$ treatment. Methods : Cytotoxic activity of BDS and its components on HASMC was using 5-(3-caroboxymeth- oxyphenyl)-2H-tetra-zolium inner salt (MTS) assay. Effect of BDS, SIS and GR on $TNF-{\alpha}-induced$ HASMC migration underside of matrigel filter was stained with hematoxylin-eosin. And total number of cells that migrated to the underside of the filter was counted. MMP-2 and MMP-9 activity was evaluated by gelatin zymography assay. Results : The matrigel migration assay showed that BDS effectively inhibited the $TNF-{\alpha}-induced$ migration of HASMC. Moreover, BDS significantly inhibited MMP-9 activity. Our present study demonstrates that BDS and its components inhibits $TNF-{\alpha}-induced$ HASMC migration and MMP-9 activity. The inhibitory effect of BDS extract is more potent than that of its component herb extracts. Conclusions : These results provide evidence that BDS has multiple effects in the inhibition of HASMC migration and may offer a therapeutic approach to block HASMC migration.

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이온마이그레이션에 대한 플라스틱과 금속첨가제의 영향 연구 (A Study on the Effect of Metallic Fillers and Plastic for Ionic Migration)

  • 전상수;김지정;이호승
    • 자동차안전학회지
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    • 제13권2호
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    • pp.30-34
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    • 2021
  • Electrical failures and reliability problems of electronic components by ionic migration between adjacent device terminals have become an issue in automotive electronics. Especially unlike galvanic corrosion, ionic migration is occurred at high temperature and high humidity under applied electric field condition. Until now, although extensive studies of the ionic migrations dealing with PCBs, electrodes, and solders were reported, there is no study on the effect of insulation polymers and metallic fillers for ionic migration. In this research, therefore, ionic migration induced by the types and contents of polymers and metallic fillers, and variety conditions of temperature, humidity, and applied voltage was studied in detail. Ester and amide types of liquid crystal polymer (LCP) and poly (phthalamide) (PPA) were used as base polymers, respectively and compounded with the metallic fillers of Copper iodide (CuI), Zinc stearate (Zn-st), or Calcium stearate (Ca-st) in various compositions. The compounding polymers were fabricated in IPC-B-24 of SIR test coupon according to ISO 9455-17 with Cu electrodes for ionic migration test. While there is no change in LCP-based samples, ionic migration in PPA compounding sample with a high water absorption property was accelerated in the presence of 0.25 wt% or above of CuI at the environmental conditions of 85℃, 85% RH and 48V. The dendritic short-circuit growth of Cu caused by ionic migration between the electrodes on the surface of compounded polymers was systematically observed and analyzed by using optical microscopy and SEM (EDX).

전자기록물 장기보존을 위한 마이그레이션 전략에 관한 연구 (A Study on Migration Strategy for Long-term Preservation of Electronic Records)

  • 권도윤;김희섭;오삼균
    • 한국기록관리학회지
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    • 제9권2호
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    • pp.19-40
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    • 2009
  • 본 연구는 마이그레이션에 대한 개념 정리와 더불어 전자기록물 장기보존을 위한 다양한 마이그레이션 전략 및 DPT, CAMiLEON 등 주요 마이그레이션 전략 적용사례에 대한 조사분석을 통해 국내 전자기록물 장기보존전략으로서 마이그레이션을 적용하기 위해 고려해야 할 시사점들을 제안하였다.