• Asian Pacific Journal of Cancer Prevention
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• 제15권1호
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• pp.167-174
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• 2014

Tumor angiogenesis, growth and metastasis are three closely related processes. We therefore investigated the effects of barbigerone on all three in the B16F10 tumor model established in both zebrafish and mouse models, and explored underlying molecular mechanisms. In vitro, barbigerone inhibited B16F10 cell proliferation, survival, migration and invasion and suppressed human umbilical vascular endothelial cell migration, invasion and tube formation in concentration-dependent manners. In the transgenic zebrafish model, treatment with $10{\mu}M$ barbigerone remarkably inhibited angiogenesis and tumor-associated angiogenesis by reducing blood vessel development more than 90%. In vivo, barbigerone significantly suppressed angiogenesis as measured by H and E staining of matrigel plugs and CD31 staining of B16F10 melanoma tumors in C57BL/6 mice. Furthermore, it exhibited highly potent activity at inhibiting tumor growth and metastasis to the lung of B16F10 melanoma cells injected into C57BL/6 mice. Western blotting revealed that barbigerone inhibited phosphorylation of AKT, FAK and MAPK family members, including ERK, JNK, and p38 MAPKs, in B16F10 cells mainly through the MEK3/6/p38 MAPK signaling pathway. These findings suggested for the first time that barbigerone could inhibit tumor-angiogenesis, tumor growth and lung metastasis via downregulation of the MEK3/6/p38 MAPK signaling pathway. The findings support further investigation of barbigerone as a potential anti-cancer drug.

• 지역연구
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• 제31권2호
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• pp.29-45
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• 2015

평균수명의 증가로 은퇴 후 생활에 대한 관심이 높아지면서 쾌적한 자연환경을 찾아 귀촌을 희망하는 가구가 증가하고 있다. 본 연구는 전국 도시가구를 대상으로 은퇴 후 귀촌을 희망하는 가구의 사회경제적 특성을 고찰하고 임의절편 로짓모형을 이용하여 귀촌 희망 요인을 분석하였다. 주거실태조사 자료를 이용한 분석 결과 도시가구의 약 27%는 은퇴 후 귀촌을 희망하고 있으며 중간 소득층, 40~50세, 고등학교 졸업 가구주의 귀촌 희망 비율이 높다. 귀촌 희망 가구는 사회경제적으로 중간계층에 속하는 집단이며, 주택보다는 소음, 대기오염 등 주거환경이 귀촌 희망여부에 유의한 영향을 미치고 있다. 즉 은퇴 후 자신의 경제적 능력으로 쾌적한 자연환경에서 좀 더 여유로운 전원생활을 누리는 것이 귀촌을 희망하는 가장 주된 이유로 볼 수 있다. 또한 고령자 중 귀촌자가 많았던 도시에서 귀촌 희망 비율이 높게 나타나 도시민들이 은퇴 후 귀촌을 희망하고 실행하는 데 귀촌에 대한 정보 제공이 중요한 역할을 할 것으로 보인다.

• Nuclear Engineering and Technology
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• 제39권6호
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• pp.747-752
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• 2007

The Proton Engineering Frontier Project (PEFP) has designed and developed a proton linear accelerator facility operating at 100 MeV - 20 mA. The radiological effects of such a nuclear facility on the environment are important in terms of radiation safety. This study estimated the production rates of radionuclides in the soil around the accelerator facility using MCNPX. The groundwater migration of the radioisotopes was also calculated using the Concentration Model. Several spallation reactions have occurred due to leaked neutrons, leading to the release of various radionuclides into the soil. The total activity of the induced radionuclides is approximately $2.98{\times}10^{-4}Bq/cm^3$ at the point of saturation. $^{45}Ca$ had the highest production rate with a specific activity of $1.78{\times}10^{-4}Bq/cm^3$ over the course of one year. $^3H$ and $^{22}Na$ are usually considered the most important radioisotopes at nuclear facilities. However, only a small amount of tritium was produced around this facility, as the energy of most neutrons is below the threshold of the predominant reactions for producing tritium: $^{16}O(n,\;X)^3H$ and $^{28}Si(n,X)^3H$ (approximately 20 MeV). The dose level of drinking water from $^{22}Na$ was $1.48{\times}10^{-5}$ pCi/ml/yr, which was less than the annual intake limit in the regulations.

• BMB Reports
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• 제52권12호
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• pp.712-717
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• 2019

Translocase of outer mitochondrial membrane 20 (TOMM20) plays an essential role as a receptor for proteins targeted to mitochondria. TOMM20 was shown to be overexpressed in various cancers. However, the oncological function and therapeutic potential for TOMM20 in cancer remains largely unexplored. The purpose of this study was to elucidate the underlying molecular mechanism of TOMM20's contribution to tumorigenesis and to explore the possibility of its therapeutic potential using colorectal cancer as a model. The results show that TOMM20 overexpression resulted in an increase in cell proliferation, migration, and invasion of colorectal cancer (CRC) cells, while siRNA-mediated inhibition of TOMM20 resulted in significant decreases in cell proliferation, migration, and invasion. TOMM20 expression directly impacted the mitochondrial function including ATP production and maintenance of membrane potential, which contributed to tumorigenic cellular activities including regulation of S phase cell cycle and apoptosis. TOMM20 was overexpressed in CRC compared to the normal tissues and increased expression of TOMM20 to be associated with malignant characteristics including a higher number of lymph nodes and perineural invasion in CRC. Notably, knockdown of TOMM20 in the xenograft mouse model resulted in a significant reduction of tumor growth. This is the first report demonstrating a relationship between TOMM20 and tumorigenesis in colorectal cancer and providing promising evidence for the potential for TOMM20 to serve as a new therapeutic target of colorectal cancer.

• 정보처리학회논문지D
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• 제11D권1호
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• pp.105-114
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• 2004

본 논문에서는 멀티 에이전트 모델에서 각 에이전트의 협력 방법을 제안하고 네이밍 에이전트의 메타데이터를 이용한 MA(Mobile Agent)의 노드 이주 알고리즘을 제시한다. 멀티 에이전트의 협력은 에이전트 시스템의 안정성과 분산 환경에서의 정보 검색의 신뢰성을 향상시킨다. 이러한 멀티 에이전트의 중요한 구성 요소 중, 네이밍 에이전트는 상호 에이전트를 식별하고 특정 객체를 참조하도록 에이전트 이름을 지원하며, 각 에이전트는 이러한 고유의 이름으로서 특정 객체를 참조한다. 또한 네이밍 에이전트는 에이전트 특성에 따라 SPA(Server Push Agent), CPA(Client Push Agent) 및 SPA(Server Push Agent) 등으로 각 에이전트를 분류하여 네이밍 서비스를 통합하고 관리하는 역할을 수행하며, 특정 MA에 노드 이주 정보를 제공하게 된다. 그러므로 MA의 노드 이주 시 적중 문건의 수, 적중률, 노드 처리 시간 및 네트워크 지연시간에 따른 우선순위를 부여하여 노드 이주의 효율성을 높일 수 있는 방안이 요구된다. 따라서 본 논문은 통합된 네이밍 서비스를 위한 네이밍 에이전트를 설계하고 적중 문건의 수, 적중률 및 탐색 문건의 수 등으로 구성된 메타데이터 구조를 보인 후, 멀티 에이전트의 협력을 통한 메타데이터의 생성과 갱신 및 적중 문건의 수에 따른 노드 이주 방법을 보인다.

• Journal of Periodontal and Implant Science
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• 제46권6호
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• pp.362-371
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• 2016

Purpose: The increasing demand for esthetically pleasing results has contributed to the use of ceramics for dental implant abutments. The aim of this study was to compare the biological response of epithelial tissue cultivated on lithium disilicate ($LS_2$) and zirconium oxide ($ZrO_2$) ceramics. Understanding the relevant physicochemical and mechanical properties of these ceramics will help identify the optimal material for facilitating gingival wound closure. Methods: Both biomaterials were prepared with 2 different surface treatments: raw and polished. Their physicochemical characteristics were analyzed by contact angle measurements, scanning white-light interferometry, and scanning electron microscopy. An organotypic culture was then performed using a chicken epithelium model to simulate peri-implant soft tissue. We measured the contact angle, hydrophobicity, and roughness of the materials as well as the tissue behavior at their surfaces (cell migration and cell adhesion). Results: The best cell migration was observed on $ZrO_2$ ceramic. Cell adhesion was also drastically lower on the polished $ZrO_2$ ceramic than on both the raw and polished $LS_2$. Evaluating various surface topographies of $LS_2$ showed that increasing surface roughness improved cell adhesion, leading to an increase of up to 13%. Conclusions: Our results demonstrate that a biomaterial, here $LS_2$, can be modified using simple surface changes in order to finely modulate soft tissue adhesion. Strong adhesion at the abutment associated with weak migration assists in gingival wound healing. On the same material, polishing can reduce cell adhesion without drastically modifying cell migration. A comparison of $LS_2$ and $ZrO_2$ ceramic showed that $LS_2$ was more conducive to creating varying tissue reactions. Our results can help dental surgeons to choose, especially for esthetic implant abutments, the most appropriate biomaterial as well as the most appropriate surface treatment to use in accordance with specific clinical dental applications.

• 대한지리학회지
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• 제47권1호
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• pp.13-36
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• 2012

이 논문은 한국에서 지난 20년 동안 급증했던 초국적 이주자들의 국내 유입과 이에 따른 사회공간적 변화에 관한 주요 세부 주제들을 전반적으로 그러나 가능한 체계적으로 성찰해보기 위한 것이다. 지구화의 불균등성과 교통통신기술의 발달 그리고 국내 경제성장과 저임금 노동력의 부족 등으로 인해 급증하게 된 외국인 이주자들은 수도권과 공단지역을 중심으로 불균등하게 분포해 있다. 이주노동자들은 단기적으로 지역경제에 긍정적 영향을 미치지만, 장기적으로 보면 오히려 부정적인 것으로 추정된다. 내국인들은 다문화의 필요성을 수용하면서도 동시에 단일민족에 대해 자부심을 가지는 이중적 태도를 보이고 있다. 중앙정부는 2000년 중반 이후 외국인 이주자들을 위하여 본격적인 다문화정책을 추진하게 되었지만, 여전히 동화주의 또는 차별배제주의를 내재하면서 이들을 주변화시키고 있으며, 지방정부의 역할은 매우 미흡한 편이다. 결론적으로, 이러한 문제들을 해결하고 다문화사회공간으로 원활하게 전환하기 위하여, 진정한 다문화주의 담론과 정책, 지방정부의 역할 증대, 지구-지방적 시민권의 보장 등을 촉구하는 초국적 이주의 지리학이 필요하다.

• 터널과지하공간
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• 제33권4호
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• pp.228-243
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• 2023

벤토나이트는 팽윤 능력과 낮은 투수율 등의 유리한 특성으로 인해 고준위방폐물처분장에서 완충재로 널리 인정받고 활용되고 있으며, 낮은 투수율로 인해 방사성 핵종이 주변 암반으로 이동하는 것을 효과적으로 방지하여 방사성 폐기물의 안전한 처분을 보장하는 데 중요한 역할을 한다. 그러나 벤토나이트 완충재의 장기적인 성능은 여전히 지속적인 연구의 대상으로 남아 있으며, 주요 우려 사항 중 하나는 벤토나이트의 팽윤과 지하수 흐름에 의한 완충재의 침식이다. 벤토나이트 완충재의 침식은 완충재의 무결성을 손상시키고 지하수를 통한 방사성 핵종의 이동을 촉진할 수 있는 콜로이드 형성을 초래하여, 결과적으로 방사성 핵종 이동 위험을 높임으로써 처분장 안전에 중대한 영향을 미칠 수 있다. 따라서 벤토나이트 완충재의 침식 메커니즘과 침식 정도를 수치 해석적으로 정량화하여 장기적인 벤토나이트 완충재의 성능 및 콜로이드 형성 정도를 평가하는 것이 고준위방폐물처분장의 안전성 평가에 매우 중요하다. 본 기술 보고에서는 동적 벤토나이트 확산 모델을 기반으로 거동이 유사한 영역을 두 개로 분류하여 벤토나이트의 균열 침투 및 콜로이드 형성을 모사할 수 있도록 제안된 모델인 Two-region 모델을 소개하였으며, 이 모델을 이용해 벤토나이트 완충재 침식 정도를 정량적으로 평가하였다.

• Journal of Korean Neurosurgical Society
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• 제54권6호
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• pp.467-476
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• 2013

Objective : This study aimed to evaluate the hypotheses that administration routes [intra-arterial (IA) vs. intravenous (IV)] affect the early stage migration of transplanted human bone marrow-derived mesenchymal stem cells (hBM-MSCs) in acute brain infarction. Methods : Male Sprague-Dawley rats (n=40) were subjected to photothrombotic infarction. Three days after photothrombotic infarction, rats were randomly allocated to one of four experimental groups [IA group : n=12, IV group : n=12, superparamagnetic iron oxide (SPIO) group : n=8, control group : n=8]. All groups were subdivided into 1, 6, 24, and 48 hours groups according to time point of sacrifice. Magnetic resonance imaging (MRI) consisting of T2 weighted image (T2WI), $T2^*$ weighted image ($T2^*WI$), susceptibility weighted image (SWI), and diffusion weighted image of rat brain were obtained prior to and at 1, 6, 24, and 48 hours post-implantation. After final MRI, rats were sacrificed and grafted cells were analyzed in brain and lung specimen using Prussian blue and immunohistochemical staining. Results : Grafted cells appeared as dark signal intensity regions at the peri-lesional zone. In IA group, dark signals in peri-lesional zone were more prominent compared with IV group. SWI showed largest dark signal followed by $T2^*WI$ and T2WI in both IA and IV groups. On Prussian blue staining, IA administration showed substantially increased migration and a large number of transplanted hBM-MSCs in the target brain than IV administration. The Prussian blue-positive cells were not detected in SPIO and control groups. Conclusion : In a rat photothrombotic model of ischemic stroke, selective IA administration of human mesenchymal stem cells is more effective than IV administration. MRI and histological analyses revealed the time course of cell migration, and the numbers and distribution of hBM-MSCs delivered into the brain.

• 한국추진공학회지
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• 제4권3호
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• pp.45-54
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• 2000

Ignition transient is a. very rapid process lasting only in the order of 100 milliseconds and therefore it is difficult to measure all relevant ballistic properties. Numerical simulation is thus useful to quantify some of these hard to measure flow and ballistic properties. One-dimensional model was employed to study the effects of aging using simplified aging scenarios for both N-H sustainer and booster motors. Also the effects of newly designed igniter on the ignition of N-H sustainer was simulated. Radiation effects could be significant in terms of energy flux increase to the propellant surface and the energy exchange between the combustion gas itself. One dimension implementation of radiation showed significant effects for rear-mounted igniter. Implementation of radiation effects into 2-D axi-symmetric numerical model was completed and its effects on the N-H sustainer were examined. To have a reliable prediction of computer model on ignition transient, accurate chemical property data on the propellant and igniter gas are required. It was found that such property data on aged N-H motors are not available. Chemical aging model can be used to predict to some degree of accuracy effects of aging on chemical and mechanical properties. Such a model was developed, albeit 2-dimensional, to study migration of moisture through a representative solid rocket motor configuration.