• Journal of Integrative Natural Science
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• v.16 no.2
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• pp.47-51
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• 2023

Ras small GTPases are involved in regulating various cellular signaling pathways including cell migration, proliferation, and differentiation. Ras GTPase subfamily is comprised of 15 proteins; 11 Ras, 3 Rap, and one Rheb related protein. Some Ras proteins, such as RasC and RasG, have been identified for their major functions, but there are proteins whose functions have not been studied yet, such as RasU and RasX. Here, we investigated the roles of RasU in cell motility and development. RasU shows the highest homology with RasX. To investigate the functions of RasU, rasU null cells were used to observe the phenotype. Cells lacking RasU were larger and more spread than wild-type cells. These results indicate that RasU plays a negative role in cell spreading. In addition, we investigated the roles of RasU in cell motility and development of Dictyostelium cells and found that rasU null cells exhibited decreased random migration speed and delayed developmental process. These results suggest that RasU plays an important role in cell motility and development.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.12B
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• pp.1087-1098
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• 2006

This study is unlike common Input-Output Analysis in the point that both RAS and methods are applied to the dynamic Input-Output Model simultaneously. We have analyzed the propagation effects on the regional economy from the investment generated by u-City construction in Wha-sung and Dong-tan City. The main results of the study are as follows. The total induced effect on production according to u-City construction in Wha-sung and Dong-tan City is estimated about 2.9 times. On the other hand, u-City industry is appreciated as a industry which a forward linkage effect is very high while a backward linkage effect is not that high.

• Proceedings of the KSRS Conference
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• 2006.03a
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• pp.36-40
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• 2006

The objective of the study is to develop a GIS-based flood map. Hydraulic model (HEC-RAS) is linked with hydrologic model (HEC-HMS) for flood map. Geospatial data processors, HEC-GeoHMS and HEC-GeoRAS, are used for operating HEC-HMS and HEC-RAS. HEC-HMS was calibrated and validated at the Hwa-Ong watershed. HEC-HMS was used for calculating runoff from the Hwa-Ong watershed which consisted of Nam-Yang, Ja-An, U-Eun river sub-watersheds, and HEC-RAS was applied and validated for river flow routing at the Hwa-Ong watershed. The simulated results from HEC-HMS and HEC-RAS were reasonably good compared with the observed data. HEC-RAS and HEC-HMS were applied to simulate flooding from probability rainfall at the Hwa-Ong watershed, and the simulated result was used to develop a flood map. Flood map developed in this study will be used for mitigating and predicting the flood damages.

• Molecules and Cells
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• v.26 no.5
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• pp.462-467
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• 2008

TPA is known to cooperate with an activated Ras oncogene in the transformation of rodent fibroblasts, but the biochemical mechanisms responsible for this effect have not been established. In the present study we used c-fos promoter-luciferase constructs as reporters, in transient transfection assays, in NIH3T3 cells to assess the mechanism of this cooperation. We found a marked synergistic interaction between TPA and a transfected v-Ha-ras oncogene in the activation of c-fos promoter and SRE. SRE has binding sites for TCF and SRF. A dominant-negative Ras (ras-N17) inhibited the TPA-Ras synergy by blocking the PKC-MAPK-TCF pathway. Dominant-negative RhoA and Rac1 (but not Cdc42Hs) inhibited the TPA-Ras synergy by blocking the Ras-Rho-SRF signaling pathway. Constitutively active $PKC{\alpha}$ and $PKC{\varepsilon}$ showed synergy with v-Ras. These results suggest that the activation of two distinct pathways such as Ras-Raf-ERK-TCF pathway and Rho-SRF pathway are responsible for the induction of c-fos by TPA and Ras in mitogenic signaling pathways.

• The Korean Journal of Quaternary Research
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• v.21 no.2
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• pp.56-57
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• 2007

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.06a
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• pp.139-142
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• 2007

본 연구는 RAS 계수법과 동태적 산업연관 모형을 동시에 적용하여 u-City 구축의 경제적 파급효과를 분석하였다는 점에서 통상적인 산업연관분석과 차별성을 지닌다. 한국은행이 가장 최근 발표한 산업연관표는 2000년도 자료이다. 본 연구는 RAS 계수법으로 알려져 있는 예측기법을 이용하여 2000년 산업연관표를 2010년 표로 연장시켜 u-City 산업의 경제적 파급효과를 분석한다. 한편 산업연관분석에 통상적으로 사용되고 있는 모형은 정태적 분석모형인 기본 산업연관 모형이지만, 본 연구에서는 동태적 산업연관 모형을 적용하여 u-City 산업의 경제적 파급효과를 동태적으로 분석하였다. u-City 구축에 따른 총 생산파급효과는 약 3.3배로 추정되었으며, u-City 산업은 전방연쇄효과는 매우 높지만 후방연쇄효과는 그다지 높지 않은 것으로 나타났다.

• Journal of Pharmacopuncture
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• v.22 no.4
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• pp.248-252
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• 2019

Objectives: The aim of the present work is evaluating the special effects of Urtica Dioica and Lamium Album on the serum level of K-Ras and GSK-3 beta in diabetic rats. Methods: In the present experimental study, 32 male Wistar rats randomly divided into 4 groups (Group I: normal control rats; receiving daily PBS, Group 2: diabetic control rats; receiving single dose of streptozotocin (60 mg/kg) and daily PBS, Group 3: Diabetic rats treated with 100 mg/kg of hydroalcoholic extract of the U. dioica, Group 4: Diabetic rats treated with 100 mg/kg of hydroalcoholic extract of L. Album. Diabetes-induced by an intraperitoneal injection of streptozotocin (60 mg/ kg). On the 14 th day of treatment, the weight, fasting blood sugar (FBS) and on 28 th day blood glucose, K-Ras and GSK3 beta was measured. Results: In diabetic group blood GSK- 3 beta increase in comparison to control group (P < 0.05), also blood K-Ras decrease in the diabetic group (P < 0.05). Both extracts reduced GSK-3 beta level, however, this reduction was only statistically significant by U.dioica (P < 0.05). Compared to diabetic group, blood K-Ras level increased by both extract (P < 0.05). Also diabetes induction increase blood glucose levels and both extracts decrease its level significantly (P < 0.05).there is no significant differences among both extract effects on blood glucose, and K-Ras. Conclusion: For the first time shown that both extracts by regulating GSK-3 beta and K-Ras improve blood glucose level. More studies are needed to determine all the effects of these herbs.

• The Korean Journal of Physiology and Pharmacology
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• v.24 no.3
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• pp.267-276
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• 2020

T In the present study, we investigated the effect of oncogenic H-Ras on rat mdr1b expression in NIH3T3 cells. The constitutive expression of H-Ras^V12 was found to downregulate the mdr1b promoter activity and mdr1b mRNA expression. The doxorubicin-induced mdr1b promoter activity of the H-Ras^V12 expressing NIH3T3 cells was markedly lower than that of control NIH3T3 cells. Additionally, there is a positive correlation between the level of H-Ras^V12 expression and a sensitivity to doxorubicin toxicity. To examine the detailed mechanism of H-Ras^V12-mediated down-regulation of mdr1b expression, antioxidant N-acetylcysteine (NAC) and NADPH oxidase inhibitor diphenylene iodonium (DPI) were used. Pretreating cells with either NAC or DPI significantly enhanced the oncogenic H-Ras-mediated down-regulation of mdr1b expression and markedly prevented doxorubicin-induced cell death. Moreover, NAC and DPI treatment led to a decrease in ERK activity, and the ERK inhibitors PD98059 or U0126 enhanced the mdr1b-Luc activity of H-Ras^V12-NIH3T3 and reduced doxorubicin-induced apoptosis. These data suggest that Ras^V12 expression could downregulate mdr1b expression through intracellular reactive oxygen species (ROS) production, and ERK activation induced by ROS, is at least in part, contributed to the downregulation of mdr1b expression.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.860-864
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• 2010

하천은 유속과 수심을 변화시키는 환경과 수역에서 고수부지까지의 다양한 지형변화, 홍수에 의한 파괴와 재생 등 하천 특유의 조건을 가지고 있어 여러 생물이 공존하여 살 수 있는 환경을 가지고 있다. 근래 하천은 친수성을 높이고 하천오염문제를 해결하기 위해 자연친화적인 하천으로 개발 방향이 바뀌고 있지만, 생물 서식처 기능 보다는 친수성이 강조되는 경우가 많다. 본 연구에서는 하천에 도입을 원하는 식생에 대한 환경유량을 분석하여 도입 가능한 하천 영역을 찾는 것이 목적이다. 연구대상지역은 황룡강이며 지형자료는 HEC-RAS의 횡단자료를 이용하여 유한요소망으로 만들어 사용하였다. 하천 식생을 고려한 환경유량을 계산하기 위하여 HEC-EFM을 이용하였다. 연구지역의 수위-유량자료, 도입 가능한 식생의 Life Cycle을 분석하여 HEC-EFM에 입력하여 환경유량을 계산하였다. 산정한 환경유량을 HEC-RAS모형으로 모의하여 환경유량에 맞는 수위 유량을 계산하고 이 결과를 HEC-GeoRAS모형을 이용하여 도입 가능한 영역을 시각화 하였다.

• Korean Journal of Veterinary Research
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• v.40 no.1
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• pp.117-129
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• 2000

This study was carried out to examine proliferative activity and expression of c-myc oncoprotein and p2lras in normal and preneoplastic rat livers induced by an in vivo mid-term chemical carcinogenesis assay. Sixty, six-week-old male specific pathogen free Sprague-Dawley male rats were randomly divided into five groups. Group I was received a single intraperitoneal(IP) dose(200mg/kg) of diethylnitrosamine(DEN). Group 2(10 rats) was operated partial hepatectomy(PH) and Group 3 was received IP(200mg/kg) DEN, fed two weeks later with 500ppm of phenobarbital(PB). Group 4 was received IP(200mg/kg) DEN, fed two weeks later 500ppm(PB) and PH at week 3 after the onset of experiment. While group 5(20 rats) was not treated and used as a control group. All the rats were sacrificed at age 14 weeks except 10 rats from group 5 were sacrificed at the onset of experiment. Livers of all rats were examined for 5-bromo-2'-deoxyuridine(BrdU) incoporation, proliferating cell nuclear antigen(PCNA), silver-binding nucleolar organizer regions(AgNORs) counts per nucleus and expression of c-myc oncoprotein and p21ras. Both the number and area of the preneoplastic lesions were significantly(p<0.01) compared to other groups. A significant(p<0.01) increase in immunoreactive cells were detected in preneoplastic hepatocytes in Groups 3 and 4 by PCNA and BrdU immunohistochemical stain. The number of the positive cells were significantly(p<0.05) lower in normal 14-week-old rats than those of 6-week-old rats. The results showed that proliferative activity of the hepatocytes was increased by treatment with DEN, PH and PB. Meanwhile, AgNORs counts per nucleus were significantly(p<0.05) increased in the preneoplastic hepatocytes of rats in both groups 3 and 4. The expression of c-myc oncoprotein and p21ras were more readily localized within the hepatic preneoplastic lesions such as hyperplastic nodules. Especially, group 4 showed significantly (p<0.05) overexpressed levels compared to groups 1 and 3. These findings suggest that PCNA, BrdU and AgNORs are significantly increased and c-myc oncoprotein and p21ras are significantly overexpressed in hepatic preneoplastic lesions induced by mid-term carcinogenesis. So these parameters can be an effective markers for hepatic prencoplastic lesions.