• 제목/요약/키워드: Spreading Dynamics

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Ginsenoside Rg1 suppresses cancer cell proliferation through perturbing mitotic progression

  • Hong, Jihee;Gwon, Dasom;Jang, Chang-Young
    • Journal of Ginseng Research
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    • 제46권3호
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    • pp.481-488
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    • 2022
  • Background: Although the tumor-suppressive effects of ginsenosides in cell cycle have been well established, their pharmacological properties in mitosis have not been clarified yet. The chromosomal instability resulting from dysregulated mitotic processes is usually increased in cancer. In this study, we aimed to investigate the anticancer effects of ginsenoside Rg1 on mitotic progression in cancer. Materials and methods: Cancer cells were treated with ginsenoside Rg1 and their morphology and intensity of different protein were analyzed using immunofluorescence microscopy. The level of proteins in chromosomes was compared through chromosomal fractionation and Western blot analyses. The location and intensity of proteins in the chromosome were confirmed through immunostaining of mitotic chromosome after spreading. The colony formation assays were conducted using various cancer cell lines. Results: Ginsenoside Rg1 reduced cancer cell proliferation in some cancers through inducing mitotic arrest. Mechanistically, it inhibits the phosphorylation of histone H3 Thr3 (H3T3ph) mediated by Haspin kinase and concomitant recruitment of chromosomal passenger complex (CPC) to the centromere. Depletion of Aurora B at the centromere led to abnormal centromere integrity and spindle dynamics, thereby causing mitotic defects, such as increase in the width of the metaphase plate and spindle instability, resulting in delayed mitotic progression and cancer cell proliferation. Conclusion: Ginsenoside Rg1 reduces the level of Aurora B at the centromere via perturbing Haspin kinase activity and concurrent H3T3ph. Therefore, ginsenoside Rg1 suppresses cancer cell proliferation through impeding mitotic processes, such as chromosome alignment and spindle dynamics, upon depletion of Aurora B from the centromere.

지역방송의 지역성 및 다문화주의 반영에 관한 연구 (A Study on the Reflect of the Locality and the Multiculturalism in the Local Broadcasting)

  • 홍숙영
    • 디지털융복합연구
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    • 제6권3호
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    • pp.149-158
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    • 2008
  • This study identifies the present status of multicultural broadcasting programs as multicultural phenomenon is spreading throughout Korean society and it discusses how a local broadcasting has to reflect locality and multicultural characteristic. A notion on the local of multimedia and multichannel time is expanding as a concept of emotional and psychological territory over geographical space. Therefore the locality should reflect attachment and interests of its members as well as disseminating multicultural reality. A locality for broadcasting should accept differences, reflect a cultural diversity, and satisfy its dynamics. The purpose of this study is to inquire whether a local broadcasting is performing its function as a local press and a place forpublic opinions by examining how they reflect reality of local, where an inflow of Immigrants and their cultures are altering the place as a multicultural society, and what Programs they propose. This study also presents media education for immigrants, revitalization of community, multicultural education about local citizens, and practical use of multicultural contents and small output radio as a source of supply for local broadcasting program in order to harmonize production of multlcultural media contents In local society.

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배연탈황설비 흡수탑 내 연소가스 및 슬러리의 거동에 관한 수치해석적 연구 (Numerical Analysis on the Flue Gas Flow and Slurry Behavior in the Absorber of a Flue Gas Desulphurization (FGD) System)

  • 최청렬
    • 한국대기환경학회지
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    • 제23권4호
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    • pp.478-486
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    • 2007
  • Numerical analysis had been performed to understand flow characteristics of the flue gas and slurry in the absorber of a flue gas desulphurization (FGD) system using computational fluid dynamics (CFD) technique. Two-fluid(Euler-Lagrangian) model had been employed to simulate physical phenomenon, which slurry particles injected through slurry spray nozzles fall down and bump into the flue gas inflowing through inlet duct. It was not necessary to adopt pre-defined pressure drop inside the absorber because interaction between flue gas and slurry particles was considered. Hundreds of slurry spray nozzles were considered with the spray velocity at the nozzles, swirl velocity and spreading angle. The results note that the flow disturbance of flue gas is found at the bottom of the absorber, and the current rising with high speed stream is observed in the opposite region of the inflow duct. The high speed stream is reduced as the flue gas goes up, because the high speed stream of flue gas dumps falling slurry particles due to momentum exchange between flue gas and slurry particles. In spite of some disproportion in slurry distribution inside the absorber, escape of slurry particles from the absorber facility is not observed. The pressure drop inside the absorber is mainly occurred at the bottom section.

수처리 교반기용 프로펠러의 3차원 유동 전산 해석 및 성능 특성 분석 (THREE-DIMENSIONAL FLOW COMPUTATION AND PERFORMANCE CHARACTERISTICS ANALYSIS OF PROPELLERS FOR WATER TREATMENT MIXER)

  • 배용균;김대한;황승태;문영준
    • 한국전산유체공학회지
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    • 제20권1호
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    • pp.10-15
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    • 2015
  • In this study, the characteristics of water treatment mixer with various propeller profiles are numerically invesitgated. The computation was conducted by solving the incompressible Navier-Stokes equations on unstructured tetrahedral elements with k-${\varepsilon}$ turbulence model. It was found that the spreading angle and swirl magnitude of the jet are important factors for the mixer efficiency, since they clearly characterize the propeller and the frontal surface area of the propeller but not so much affected by the skew angle if it exceeds 30 degrees. The case1 and case2 models are found to show the best propeller efficiency. The case2 with low blade angle, however, requires the lowest power input for the same discharge capacity as the case1.

Structure of a single polymer chain confined in a dense array of nanoposts

  • Joo, Heesun;Kim, Jun soo
    • EDISON SW 활용 경진대회 논문집
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    • 제4회(2015년)
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    • pp.48-52
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    • 2015
  • Control of polymer conformations in heterogeneous confinement plays an important role in natural and engineering processes. We present a simulation study on the conformational structure and dynamics of a single, flexible polymer in a dense array of nanoposts with different sizes and separations, especially, when the volume of the interstitial space formed between four nanoposts is less than the size of the polymer chain. When a polymer is placed in the array of nanoposts, the size of polymer increases compared with that in the absence of nanoposts due to the confinement effect. It is shown that when a polymer is confined in the array of nanoposts the chain is elongated in the direction parallel to the nanoposts. As the interstitial volume between four nanoposts decreases either by increasing the nanopost diameter or by decreasing the separation between nanoposts, the chain elongation becomes more pronounced. On the contrary, the polymer size varies in a non-monotonic fashion, with an initial elongation followed by a chain contraction, as the interstitial volume is reduced both by increasing the nanopost diameter and decreasing the separation at the same time while keeping constant the width of the passageway between two nanoposts. The simulation analysis shows that the non-monotonic dependence of polymer size is determined by interplay between the chain alignment along the nanoposts in each interstitial volume and the chain spreading through passageways over several interstitial volume.

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반생산적인 업무행동에 대한 자기애적 성격특성의 이해 (Counterproductive Work Behaviors and Narcissism)

  • 주원식;차타순
    • 경영과정보연구
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    • 제10권
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    • pp.33-66
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    • 2002
  • Counterproductive work behaviors are behaviors by employees intended to harm their organization or organization members. Human is the being has a desire and behaviors. To understand behaviors of an individual, it is important to understand the personality which determines a difference between individuals. Narcissists has psychological traits to be likely to experience negative emotions, such as frustration, hostility or anger, and this psychological traits of narcissists are more likely to induce an aggression. In this view, the purpose of this study was to examine the relationships between counterproductive work behaviors and narcissistic personality characteristics and to explore psychological dynamics about how narcissistic personality characteristics had an effect on counterproductive work behaviors. As a result, facts known were as follows. First, narcissists has strong desires to maintain a sense of superiority over others and defend their egos against unpleasant evaluation information, even if the information is factual and accurate. Second, narcissists are hyper-sensitive to negative information and are more likely to encounter information or situations that challenge their positive self-appraisals by this view. Third, in response to these challenges, or ego threats, these individuals are more likely to experience negative emotions, such as anger, frustration, or hostility. Forth, this negative emotions lead to aggression and as a result, this is more likely to induce counterproductive work behaviors such as theft, sabotage, interpersonal aggression, work slowdowns, wasting time and materials, and spreading rumors. Thus, narcissism is another individual difference variable that may be an important factor in determining counterproductive work behaviors, particularly under conditions perceived to be difficult or stressful.

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그룹웨어의 현황 분석 Ⅰ (Groupware Current Status Analysis Ⅰ)

  • 김선욱;김봉진
    • 산업공학
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    • 제10권3호
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    • pp.75-93
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    • 1997
  • Unlike individual applications, it is extremely hard to obtain user requirements for group systems, since there exists very complicated dynamics in group. This may result in spreading a great amount of products with a broad range of contents. Thus, this study presents a comparative analysis of groupware products. As a result, these products have been categorized into three areas which include cooperation/document management systems, collaborative writing systems, and decision-making/meeting systems. While the systems reviewed here focus on the cooperation/document management systems, the other two areas will be dealt in details in part Ⅱ. The first area ends up with two large categories such as proprietary groupware products and intranet groupware products. However, it has been observed that there is a natural convergence between these two categories. Consequently, the comparative analysis has been performed in terms of functions provided on the two categories and a combined category. Each group of the functions has been divided into three parts which consist of basic functions, quasi-basic functions, and others. Such a decision has been made based on the frequency rate of the functions provided in the products. With a more strict rule, the basic functions comprise electronic mail, sanction, bulletin board, document management, scheduling, security, Web browser, and Internet connectivity. This study also provides a framework for integrated functional model of groupware systems. The basic functions are merged into the model. However, the model is so flexible that it can partially include the quasi-functions in addition to the basic functions. In the future, it is expected that a large number of products will stem from the modification of the functional model.

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고온 벽면과 충돌하는 단일 액적의 거동에 관한 연구 (A Study on the Behavior of a Droplet Impacting onto a Heated Surface)

  • 강보선;이동환
    • 대한기계학회논문집B
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    • 제23권7호
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    • pp.871-880
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    • 1999
  • In this paper an experimental study is presented of the problem of dynamic behavior of a water droplet impinging upon a heated surface. The experiments are mainly focused on the effects of impinging angle of a droplet and surface temperature on the impact dynamics of the droplet. It Is clarified that the droplet exhibits much different behavior depending on the normal momentum of an impinging droplet before impact. At surface temperature In the nucleate boiling regime. the disintegration of a droplet doesn't occur, whereas the deforming droplet adheres to the surface. The spreading and contraction of the liquid film is repeated a couple of times for the horizontal surface but the expanded droplet just slips without noticeable contraction for the inclined surfaces. In the film boiling regime, the impinging droplet spreads over the surface as a liquid film which is separated from the surface by produced vapor. Depending on the magnitude of the normal momentum of the droplet the disintegration into the several irregular shapes of liquid elements occurs for the horizontal and 30o-inclined surfaces, whereas the impinging droplet for the 60o-inclined surface doesn't break up and tends to recover the original spherical shape.

Impact of parthenium weed invasion on plants and their soil seedbank in a subtropical grassland, central Nepal

  • Khatri-Chettri, Jyoti;Rokaya, Maan Bahadur;Shrestha, Bharat Babu
    • Journal of Ecology and Environment
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    • 제46권1호
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    • pp.8-17
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    • 2022
  • Background: Parthenium hysterophorus L. (Asteraceae; hereafter Parthenium) is an invasive alien species of global significance because of its' negative ecological and socioeconomic impacts. This species is spreading rapidly from lowland Tarai to Middle Mountain regions in Nepal. In the present study, we analyzed the impacts of Parthenium on plant community composition including their soil seedbank in subtropical grasslands located in central Nepal. Data was collected in a 10 m long transects passing through areas of high (> 90% cover), medium (40%-60%) and low (< 10%) levels of Parthenium cover using a plot of 1 m2. Altogether, we sampled 90 plots in 30 transects. Seedling emergence method was used to estimate soil seedbank density in the soil samples (0-10 cm depth) collected from the plots with high Parthenium cover. Results: There was no significant difference in the plant species richness at different levels of Parthenium invasion whereas there was a significant change in the species composition of above ground flora due to Parthenium invasion. There was also a significant difference in species composition between soil seedbank and aboveground flora in the highly invaded plots. Parthenium was the most dominant in soil seedbank, contributing 65% to the total soil seedbank. Conclusions: Our study suggests that Parthenium has considerable negative impact on the native grassland flora, and the dominance of Parthenium in the soil seedbank means there is a challenge for its management. It also suggests the need of monitoring the soil seedbank dynamics while managing Parthenium weed.

산불확산패턴 연구를 위한 시뮬레이션 모델 (A Simulation Model for the Study on the Forest Fire Pattern)

  • 송학수;전원주;이상희
    • 한국시뮬레이션학회논문지
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    • 제22권2호
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    • pp.101-107
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    • 2013
  • 최근 지구 온난화 현상으로 이상기후가 세계 곳곳 에서 발생하고 있으며, 이는 빈번한 산불 발생 및 산불의 대형화에 많은 기여를 하고 있다는 것이 보고되고 있다. 산불은 재산피해, 인명피해 뿐만 아니라 특히, 생태계 파괴를 촉진시키는 매우 심각한 요인 중의 하나이다. 산불로 인한 생태계 파괴 문제를 해결하기 위한 방안으로, 다양한 산불확산 및 패턴 수리모델이 개발되어져 왔다. 본 연구에서는, 바람 요인이 고려된 산불패턴을 시뮬레이션 할 수 있는 수리 모델을 제안하였다. 모델은 격자기반위에서 구성되었으며 셀룰라오토마타 방법을 사용하였다. 모델에서, 숲은 불이 쉽게 옮겨 붙는 나무와 그렇지 않은 나무 두 종류로 구성되었다. 산불이 확산되는 과정에서 연소된 나무의 개수가 전체 시뮬레이션 격자개수의 25% (= 10,000) 되는 시점(T)을 세 개의 독립변수인, 전체 나무밀도, 불 전이 확률이 큰 나무 밀도, 그리고 바람의 세기에 대해 어떤 영향을 받는지를 조사하였다. 나무 밀도가 커질수록, T의 값은 줄어들었고, 바람의 세기가 커질수록 T의 값이 줄어들었다. 나무밀도가 너무 크거나 작은 경우, 바람의 효과가 감소하였다. 본 연구에서, 제안한 산불확산모델은 실제 산불 문제에 적용되어 효과적 대응방안 마련에 많은 도움이 될 것으로 예상된다.