• 대한토목학회논문집
• /
• 제37권1호
• /
• pp.1-7
• /
• 2017

일반적으로 구조물에 폭발, 충돌, 지진과 바람 등과 같이 짧은 시간에 큰 하중이 작용하게 되면 구조물은 국부적으로 재료의 대변형(large deformation), 대회전(large rotation), 대변형률(large strain)등이 발생하게 된다. 이와 같은 현상을 해석하려면 전산연속체 역학에 기초하여 유체-구조물 상호작용 등을 고려할 수 있는 하이드로코드(Hydrocode)의 도움이 필요하다. 또한, 폭발로 인해 발생되는 순간 동역학적인 폭발 메커니즘은 매우 복잡하기 때문에 폭발실험을 병행하여 거동을 예측하는 것이 합리적인 방법이지만 막대한 비용과 시설이 요구되므로 한계가 있는 것도 사실이다. 따라서 본 논문에서는 하이드로코드인 AUTODYN을 사용하여 폭발해석한 결과를 기수행된 철근콘크리트 슬래브의 폭발실험 결과와 비교하여 폭발해석 방법의 타당성을 검토하였고, 동일한 폭발해석 모형에 대하여 철근 배근간격, 피복두께의 변화 및 수직철근 유무에 따른 폭발 손상도를 비교검토하였다. 검토한 결과, 철근의 배근간격에 대한 철근콘크리트 슬래브 두께의 비가 커질수록, 지름이 큰 철근보다 지름이 작은 철근을 많이 사용할수록, 마지막으로 수직철근을 배근할수록 콘크리트 구조물의 내폭성능이 향상됨을 알 수 있었다.

• 한국수정란이식학회지
• /
• 제32권3호
• /
• pp.165-170
• /
• 2017

Pigs have been extensively used as mediators of xenotransplantation research. Specifically, the Massachusetts General Hospital (MGH) miniature pig was developed to fix major histocompatibility antigens for use in xenotransplantation studies. We generated transgenic pigs for xenotransplantation using MGH pigs. However, it has not been studied yet whether these pigs show similarity of reproductive physiological characteristics to wild types of MGH miniature pig. In this study we analyzed the estrous cycles and pregnancy characteristics of wild type (WT) and transgenic MGH miniature pigs, which were ${\alpha}1,3$-galactosyltransferase (GalT) heterozygous and homozygous knock-out, and membrane cofactor protein (MCP) inserted in its locus, $GalT^{-MCP/+}$ and $GalT^{-MCP/-MCP}$ pigs. Estrous cycles of WT, $GalT^{-MCP/+}$ and $GalT^{-MCP/-MCP}$ pigs were $20.9{\pm}0.74$, $20.1{\pm}1.26$, and $17.3{\pm}0.87days$, respectively, and periods of estrous were $3.2{\pm}0.10$, $3.1{\pm}0.12$, and $3.1{\pm}0.11days$. The periods of gestation of WT, $GalT^{-MCP/+}$ and $GalT^{-MCP/-MCP}$ pigs were $114.2{\pm}0.37$, $113.3{\pm}0.67$, and $115.4{\pm}0.51days$, respectively. Litter sizes of WT, $GalT^{-MCP/+}$ and $GalT^{-MCP/-MCP}$ pigs were $4.8{\pm}0.35$, $4.8{\pm}1.11$ and $3.0{\pm}0.32$ respectively. There were no significant differences on estrous cycle, periods of estrous and gestation, and litter size among WT, $GalT^{-MCP/+}$ and $GalT^{-MCP/-MCP}$ pigs, meaning that GalT knock-out and additional expression MCP of the MGH miniature pig did not effect on reproduction traits. These results provide relevant information to establish breeding system for MGH transgenic pig, and for propagation of $GalT^{-MCP/-MCP}$ pig to supply for xenotransplantation research.

• 디자인학연구
• /
• 16호
• /
• pp.213-223
• /
• 1996

원시시대부터 인간의 커뮤니케이션 수단으로 이용되어 온 일러스트레이션은 이제 우리 생활 속에서 생활의 단편적이거나 혹은 심층적인 면을 함축하여 표현하는 수단이 되었다. 즉 그것은 피터 노크(Peter Knock)의 한 잡지 일러스트레이션을 보고 어떤 예술가가 '여태껏 읽은 것 중 가자 훌륭한 기사였다'고 말 한데서도 알 수 있듯이, 일러스트레이터의 임무는 하루의 일상생활에서 아니 순간 순간의 사물의 지각을 통한 비구체적이든, 구체적이든 일러스트레이션의 소스(source)가 우리의 잠재의식 속에 남아있다고 가정할 때 이들을 추출해서 사실적으로 묘사하는 작업을 하고 있다고 할 수 있고, 그것은 어떤 미사여구를 붙인 문자 언어보다도 강한 지각작용을 불러일으킬 수 있다는 것이다. 뿐만 아니라 일러스트레이션의 활용분야는 나날이 증가하고 있으며 그 대상도 인물, 자연, 인공, 과학 등 다양해지고 따라서 이러한 시점의 일러스트레이션에서 가장 요구되는 것은 얼마나 창조적이며 참신한 아이디어를 지녔냐 하는 것이다. 왜냐하면 복잡 다양한 사회 속에서 일반인의 마음속에 자리잡기 위해서는 보다 독특한 이미지와 호소력을 가져야 하기 때문이다. 따라서 일러스트레이션의 교육도 이젠 단순한 기술연마가 아닌 시넥틱스(Synetics)적 사고에 바탕을 둔 작품으로 유도되어야하며 기능 위주의 도식적인 일러스트이션 교육에서 벗어난 보다 자유롭고 풍부한 개성을 지닌 사고를 할 수 있도록 되어야 한다.

• 생명과학회지
• /
• 제26권2호
• /
• pp.174-180
• /
• 2016

Dicumarol는 전동싸리 식물에서 추출한 coumarin 유도체로 vitamin K 의존적으로 항응고 작용를 한다. 그러나, dicumarol에 의한 MMP-9의 발현 및 활성화 조절에 대한 연구는 수행되지 않았다. 본 연구에서 dicumarol이 인간 신장암 Caki세포에서 PMA 매개의 MMP-9의 발현과 활성화를 조절 할 수 있는지 확인하였다. Dicumarol는 PMA유도 MMP-9의 활성을 억제하였고, MMP-9의 mRNA RT-PCR 및 promoter assay를 통하여 전사단계에서 조절됨을 확인하였다. Dicumarol에 의한 MMP-9 발현 조절에 NF-κB와 AP1 전사인자의 전사 활성 저해에 의하여 야기됨을 확인하였다. NQO1 siRNA를 이용한 knock-down 실험에서 dicumarol이 PMA유도의 MMP-9 활성 억제에 NQO1의 관련성을 확인 할 수 없었다. Dicumarol는 PMA에 의한 세포이동 및 침윤을 억제하였는데, 이러한 현상은 MMP-9의 발현 및 활성을 조절함으로써 일어날 수 있음을 확인하였다.

• 생명과학회지
• /
• 제17권3호통권83호
• /
• pp.396-401
• /
• 2007

천식이 유발된 Balb/c마우스와 동일한 조건의 IL-10 KO 마우스에 천식의 원인으로 알려진 DEP와 지하철역내에서 채집한 PM (10 ${\mu}g/m^3$)을 inhalation chamber,에 넣고 하루 4시간씩 흡입시킨 후 시료들을 채취하여 ICAM-1, VCAM-1의발현을 살펴 천식증상의 악화에 DEP와 PM이 어데한 영향을 미치는지 확인하였다. 본 실험의 결과 천식이 유발된 일반 Balb/c 마우스에 있어서는 DEP와 PM의 노출에 의하여 ICAM-1 및 VCAM-1의 발현이 세기관지 주위 조직들에서 미약하게 증가하였다. 그러나 IL-10 KO 마우스의 경우 DEP와 PM을 노출시켰을 때 ICAM-1 및 VCAM-1의 발현이 아주 강하게 증가하였다. 따라서, 본 결과는 IL-10에 대한 항체요법이 천식증상의 완화에 쓰일 수 있는 가능성을 암시하며, 한편 자동차 배기가스와 지하철 미세분진의 발생을 예방할 경우 천식과 관련한 세기관지의 염증을 완화시킬 수 있음을 간접적으로 증명한 것이라 할 수 있다.

• 한국수정란이식학회지
• /
• 제32권3호
• /
• pp.87-94
• /
• 2017

Tissue engineering (TE) has been developed to create functional organs and tissue by combining 3D matrix and cells in vitro. Vascularization and angiogenesis are utmost important for supply of nutrients and oxygen in tissue engineered organs. The present study was performed to isolate and characterize primary endothelial cells (EC) from aorta of alpha 1, 3-enzyme galactosyltransferase knock out (GalT KO) pig, to minimize immune rejection and analyze body immune system for future xenotransplantation studies. Isolation of primary EC from aorta were performed by incubation with dispase for 8-10 min at $37^{\circ}C$. Primary EC were cultured in EC growth medium on different extra cellular matrix (ECM), either collagen or gelation. Primary EC exhibits morphological characteristics and showed positive expressions of EC specific marker proteins i.e. PECAM1, KDR and VWF despite of their ECM surface; however, on collagen based surface they showed increase in mRNA level analyzed by qPCR. Primary EC cultured on collagen were sorted by flow cytometer using KDR marker and cultured as KDR positive cells and KDR negative cells, respectively. KDR positive cells showed dramatically increased in PECAM1 and VWF level as compared to KDR negative cells. Based on the above results, primary EC derived from GalT KO are successfully isolated and survived continuously in culture without becoming overgrown by fibroblast. Therefore, they can be utilize for xeno organ transfer, tissue engineering, and immune rejection study in future.

• Molecules and Cells
• /
• 제41권12호
• /
• pp.1008-1015
• /
• 2018

$I{\kappa}B$, a cytoplasmic inhibitor of nuclear factor-${\kappa}B$ ($NF-{\kappa}B$), is reportedly degraded via the proteasome. However, we recently found that long-term incubation with proteasome inhibitors (PIs) such as PS-341 or MG132 induces $I{\kappa}B{\alpha}$ degradation via an alternative pathway, lysosome, which results in $NF-{\kappa}B$ activation and confers resistance to PI-induced lung cancer cell death. To enhance the anti-cancer efficacy of PIs, elucidation of the regulatory mechanism of PI-induced $I{\kappa}B{\alpha}$ degradation is necessary. Here, we demonstrated that PI up-regulates nuclear factor (erythroid-derived 2)-like 2 (Nrf2) via both de novo protein synthesis and Kelch-like ECH-associated protein 1 (KEAP1) degradation, which is responsible for $I{\kappa}B{\alpha}$ degradation via macroautophagy activation. PIs increased the protein level of light chain 3B (LC3B, macroautophagy marker), but not lysosome-associated membrane protein 2a (Lamp2a, the receptor for chaperone-mediated autophagy) in NCI-H157 and A549 lung cancer cells. Pretreatment with macroautophagy inhibitor or knock-down of LC3B blocked PI-induced $I{\kappa}B{\alpha}$ degradation. PIs up-regulated Nrf2 by increasing its transcription and mediating degradation of KEAP1 (cytoplasmic inhibitor of Nrf2). Overexpression of dominant-negative Nrf2, which lacks an N-terminal transactivating domain, or knock-down of Nrf2 suppressed PI-induced LC3B protein expression and subsequent $I{\kappa}B{\alpha}$ degradation. Thus, blocking of the Nrf2 pathway enhanced PI-induced cell death. These findings suggest that Nrf2-driven induction of LC3B plays an essential role in PI-induced activation of the $I{\kappa}B$/$NF-{\kappa}B$ pathway, which attenuates the anti-tumor efficacy of PIs.

• Journal of Plant Biotechnology
• /
• 제39권2호
• /
• pp.106-113
• /
• 2012

Glycolysis is responsible for the conversion of glucose into pyruvate and for supplying reducing power and several metabolites. Fructose-1,6-bisphosphate aldolase (AtFBA1), a central enzyme in the glycolysis pathway, was isolated by functional complementation of the salt-sensitive phenotype of a calcineurin (CaN)-deficient yeast mutant. Under high salinity conditions, aldolase activity and the concentration of NADH were compromised. However, expression of AtFBA1 maintained aldolase activity and the NADH level in yeast cells. AtFBA1 shares a high degree of sequence identity with known class I type aldolases, and its expression was negatively regulated by stress conditions including NaCl. The fusion protein GFP-AtFBA1 was localized in the cytosol of Arabidopsis protoplasts. The seed germination and root elongation of AtFBA1 knock-out plants exhibited sensitivity to ABA and salt stress. These results indicate that AtFBA1 expression and aldolase activity is important for stress tolerance in yeast and plants.

• IMMUNE NETWORK
• /
• 제9권6호
• /
• pp.274-284
• /
• 2009

Background: Swiprosin-1 was identified in human CD8+ lymphocytes, mature B cells and non-lymphonoid tissue. We have recently reported that swiprosin-1 is expressed in mast cells and up-regulated in both in vitro and in vivo. Methods: The expression of cytokines and swiprosin-1 were determined by by real time PCR and conventional PCR. Pharmacological inhibitors were treated to investigate potential mechanism of swiprosin-1 in mast cell activation. Actin content was evaluated by confocal microscopy and flow cytometry. Results: The swiprosin-1 augmented PMA/A23187-induced expression of cytokines and release of histamine. However, knock-down of swiprosin-1 showed only a modest effect on PMA/A23187-induced cytokine expression, suggesting that swiprosin-1 has gain-of-function characteristics. Swiprosin-1 was found in microvilli-like membrane protrusions and highly co-localized with F-actin. Importantly, either disruption of actin by cytochalasin B or inhibition of PI3 kinase, an enzyme involved in actin remodeling, by wortmannin blocked cytokine expression only in swiprosin-1-overexpressing cells. Conclusion: These results suggest that swiprosin-1 modulates mast cell activation potentially through actin regulation.

• Asian Pacific Journal of Cancer Prevention
• /
• 제13권2호
• /
• pp.633-636
• /
• 2012

Purpose: PRIL (proliferation-inducing ligand) is a newly identified member of the tumor necrosis factor (TNF) family and modulates death ligand-induced apoptosis. Here, we investigated the effect of PRIL on cellular characteristics relating to tumor progression in human gastric cancer. Method: Recombinant lentivirus containing PRIL siRNA was constructed and then infected MGC803 and SGC7901 gastric cancer cells. MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] colony formation and cell cycle analysis were used to study the effect of PRIL knockdown on gastric cancer cell proliferation. Results: PRIL expression in lentivirus infected cells was significantly reduced as evidenced by quantitative real-time PCR. Cell viability and colony formation of MGC803 and SGC7901 cells were significantly hampered in PRIL knock-down cells. Moreover, the cell cycle was arrested at G2/M phase, elucidating the mechanism underlying the inhibitory effect of siRNA on cell proliferation. Conclusions: Our study indicated that PRIL functions in promoting cell growth, and lentivirus-mediated PRIL gene knockdown might be a promising strategy in the treatment of gastric cancer.