• Title/Summary/Keyword: Rac3

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Ara - C유도체의 항암작용에 관한 연구 (2) : 암세포에 대한 Ara-C 유도체의 항암효과에 대한 in vitro 연구 및 독성연구

  • Lee, Hyung-Hwan;Cho, Dong-In;Ji, Yong-Hoon;Lee, Chul-Kyu;Kang, Heon;Choi, Hee-Baek;Lee, Hye-Yeol;Kim, Eun-Tae;Kanter, P.M.;Creaven, P.J.;West, C.R.
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1994.04a
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    • pp.200-200
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    • 1994
  • Thioglycerol과 g1ycerol로부터 rac-1-S-octa-decyl-2-O-palmitoyl-1-S-thioglycerol-3-phosphate (DL -PTBA-P)와 rac -1-O-octadecyl -2-O-palmitoyl-g1ycerol-3-phosphate (DL-PBA-P)등을 합성하였고, 이들에 ara-C유도체인 ara-CMP morpholidate를 반응시켜 최종 산물인 ara-CDP-DL-PCA, ara-CDP-DL-PBA, ara-CDP-DL-PTCA 및 ara-CDP-DL-PTBA등을 합성하였다. 이들 최종 산물의 항암효과는 L1210 lymphoid leukemia, P388 leukemia등의 암세포주를 사용하여 실험하였다. 암세포인 L1210, P388 leukemia 세포의 성장에 대한ara-CDP-DL-PTBA의 시험관 내 세포성장 억제정도를 알아보기 위하여 비색법인 MTT방법을 시행하였으며, 검체의 세포성장 억제능을 비교하기 위하여 대조군으로 5-Fluorouracil (5-FU)을 사용하였다.

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Reduction of eco-toxicity risk of heavy metals in the rotary drum composting of water hyacinth: Waste lime application and mechanisms

  • Singh, Jiwan;Kalamdhad, Ajay S.;Lee, Byeong-Kyu
    • Environmental Engineering Research
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    • v.20 no.3
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    • pp.212-222
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    • 2015
  • Experiments were conducted on the immobilization of eight heavy metals (HMs) (Zn, Cu, Mn, Fe, Ni, Pb, Cd, and Cr) during 20-day rotary drum composting of water hyacinth. The Tessier sequential extraction procedure was used to investigate the fractionation of HMs. The eco-toxicity risk of HMs was assessed by risk assessment code (RAC). In the results, the bioavailability factor (BAF) for different HMs presented in the following order: Mn > Zn = Fe > Cu > Cr > Cd = Pb > Ni. The total concentration of Pb was higher than that of Zn, Cu, Mn, Cd and Cr; however, its BAF was the lowest among these HMs. These results confirmed that the eco-toxicity of HMs depends on bioavailable fractions rather than on the total concentration. The greatest reduction in bioavailability and eco-toxicity risk of HMs occurred in lime 1% and 2% as compared to control and lime 3%. The eco-toxicity risk of Fe, Ni, Pb, Cd and Cr was reduced from low risk to zero risk by rotary drum composting. These studies demonstrated the high efficiency of the rotary drum for degrading compost materials and for reducing the bioavailability and eco-toxicity risk of HMs during the composting process.

Compressive and flexural behaviour of recycled aggregate concrete filled steel tubes (RACFST) under short-term loadings

  • Yang, You-Fu;Han, Lin-Hai
    • Steel and Composite Structures
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    • v.6 no.3
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    • pp.257-284
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    • 2006
  • The behaviour of hollow structural steel (HSS) stub columns and beams filled with normal concrete and recycled aggregate concrete (RAC) under instantaneous loading was investigated experimentally. A total of 40 specimens, including 30 stub columns and 10 beams, were tested. The main parameters varied in the tests were: (1) recycled coarse aggregate (RCA) replacement ratio, from 0 to 50%, (2) sectional type, circular and square. The main objectives of these tests were threefold: first, to describe a series of tests on new composite columns; second, to analyze the influence of RCA replacement ratio on the compressive and flexural behaviour of recycled aggregate concrete filled steel tubes (RACFST), and finally, to compare the accuracy of the predicted ultimate strength, bending moment capacity and flexural stiffness of the composite specimens by using the recommendations of ACI318-99 (1999), AIJ (1997), AISC-LRFD (1999), BS5400 (1979), DBJ13-51-2003 (2003) and EC4 (1994).

The Comparison between Ziegler-Natta and Zirconocene Catalyst on Reaction Conditions and Physical Properties in Polymer in Propylene Polymerization (프로필렌 중합에 있어서 Ziegler-Natta 촉매와 Zirconocene 촉매의 중합 조건과 중합체의 물성 비교)

  • 이성철;남영곤;정석진
    • Polymer(Korea)
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    • v.24 no.4
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    • pp.437-444
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    • 2000
  • Propylene polymerizations were carried out by using rac-Et(Ind)$_2$ZrCl$_2$ (Zirconocene catalyst) and a commercial third generation Ziegler-Natta catalyst in a semibatch reactor. From the polymerization reactions, the optimum reaction conditions and the physical properties of polymers produced from each catalyst system were investigated. The optimum reaction temperatures of rac-Et(Ind)$_2$ZrCl$_2$ and Ziegler-Natta catalyst were 5$0^{\circ}C$, 4$0^{\circ}C$, respectively. On the basis of the results for the produced polymer particle size distributions and the catalytic activities of polymerization reaction, the reaction temperature should be considered as an important factor for the successful polymerization reactions. Especially, the polymer was conglomerated in the higher reaction temperature. It was found that there was an upper limitation to co-catalyst concentration. Reaction rates and polymer yields rather decreased with increasing the concentration of to-catalyst, i.e., MAO and TEAl affected only polymerization activities, but the PEEB in Ziegler-Natta catalyst system affected isotactic indexes of produced polymer as well as activities. Based on these observations, the production yield seems to exhibit a first order lineal relationship to the partial pressure of monomer.

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Roles of Phosphatidylinositol 3-Kinase(PI3K) and Rac1

  • Shin, Il-Chung;Kim, Seon-Hoe;Moon, A-Ree
    • Proceedings of the PSK Conference
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    • 2003.04a
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    • pp.223.1-223.1
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    • 2003
  • Many studies have identified the phosphatidylinositol 3-kinase (PI3K) as a key regulator for various cellular functions including cell survival, growth and motility. We have previously shown that H-ras, but not N-ras. induces invasiveness and motility in human breast epithelial cells (MCF10A), while both H-ras and N-ras induce transformed phenotype. In the present study, we wished to investigate the functional role of PI3K pathway in H-ra-induced invasive phenotype and motility of MCF10A cells. (omitted)

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Non-contact 3-dimensional Coordinate Measurement by Pulse Magnetic Field Method (펄스자기장을 이용한 비접촉 3차원 좌표 측정)

  • Kim, H. J.;Son, De-Rac;Cho, Y.
    • Proceedings of the Korean Magnestics Society Conference
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    • 2002.12a
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    • pp.128-129
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    • 2002
  • 최근 컴퓨터의 계산속도가 빨라짐에 따라 데이터를 가지고 실시간 영상처리에 대한 많은 연구가 이루어지면서 인터넷을 이용한 온라인 게임, PC 게임, 방송 등의 엔터테인먼트 산업에서 멀티미디어 시장이 증가하게 되고 동영상 및 3차원 영상매체를 제작하는데 복합적 고도 기술의 필요성이 대두되어지고 있다. (중략)

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Induction of c-Jun Expression by Breast Cancer Anti-estrogen Resistance-3 (BCAR3) in Human Breast MCF-12A Cells (정상적인 인간유방상피세포인 MCF-12세포에서 유방암 항에스토젠 내성인자-3 (BCAR3)에 의한 c-Jun 발현 유도 연구)

  • Oh, Myung-Ju;Kim, Ji-Hyun;Jhun, Byung Hak
    • Journal of Life Science
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    • v.26 no.12
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    • pp.1383-1391
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    • 2016
  • Anti-estrogen drugs such as tamoxifen have been used for treating patients with ER-positive, early breast cancer. However, resistance to anti-estrogen treatment is inevitable in most patients. Breast cancer anti-estrogen resistance-3 (BCAR3) has been identified as the protein responsible for the induction of tamoxifen resistance in estrogen-dependent human breast cancer. We have previously reported that BCAR3 regulates the cell cycle progression and the signaling pathway of EGF and insulin leading to DNA synthesis. In this study, we investigated the functional role of BCAR3 in regulating c-Jun transcription in non-tumorigenic human breast epithelial MCF-12A cells. A transient transfection of BCAR3 increased both the mRNA and protein of c-Jun expression, and stable expression of BCAR3 increased c-Jun protein expression. The overexpression of BCAR3 directly activated the promoter of c-jun, AP-1, and SRE but not that of $NF-{\kappa}B$. Furthermore, single-cell microinjection of BCAR3 expression plasmid in the cell cycle-arrested MCF-12A cells induced c-Jun protein expression, and co-injection of dominant negative mutants of Ras, Rac, and Rho suppressed the transcriptional activity of c-Jun in the presence of BCAR3. Furthermore, stable expression of BCAR3 increased the proliferation of MCF-12A cells. The microinjection of inhibitory materials such as anti-BCAR3 antibody and siRNA BCAR3 inhibited EGF-induced c-Jun expression but did not affect IGF-1 induced upregulation of c-Jun. Taken together, we propose that BCAR3 plays a crucial role in c-Jun protein expression and cell proliferation and that small GTPases (e.g., Ras, Rac, and Rho) are required for the BCAR3-mediated activation of c-Jun expression.

Cancer Gene Therapy : Chemosensitization by an Enzyme-Prodrug Activation Strategy

  • Chung, Injae
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1997.11a
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    • pp.35-39
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    • 1997
  • Recent development of human genetics and techniques of gene transfer and expression have opened the way for investigating novel approaches based on the genetic modification of cells to treat both inherited and acquired diseases. This approach is referred to as gene therapy. Over the past few years, gene therapy has moved from the laboratory to phase I clinical trials. Although the clinical performance of gene transfer experiments is still in an early phase of development, the NIH of Health Recombinant DNA Advisory Comittee (RAC) has approved more than 150 protocols that involve gene transfer or putative gene therapy procedures in clinical settings. Many sectors of society in United States have participated in the design and formulation of these clinical trials through local Institutional Review Boards, the National Institutes of Health (NIH) RAC, the Chemotherapy Evaluation Program of the National Cancer institute, and the FDA. Currently, clinical trials involving gene modification are under way at many medical centers throughout the United Slates. The goals of these trials are as follows. (1) The design should be directed to short-term achievable goals. (2) Each clinical trial is best considered as an intermediate step in a multistep process. (3) The design should identify evaluable proximate endpoints for toxicity and for efficacy, (4) The potential benefits and possible risks for patients participating in these trial should be defined.

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Isospecific Propylene Polymerization Behavior of Lewis Base Functionalized Unbridged Zirconocences under Bulk Conditions

  • Yoon, Seung Woong;Kim, Hwa Kyu;Kim, Seong Kyun;Kim, Taewon;Lee, Min Hyung;Do, Youngkyu
    • Bulletin of the Korean Chemical Society
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    • v.35 no.1
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    • pp.236-242
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    • 2014
  • Isospecific propylene polymerization behavior of meta- and para-Lewis base (E) functionalized unbridged zirconocenes ($[1-(E_n-Ph)-3,4-Me_2C_5H_2]_2ZrCl_2$, E = $NMe_2$, OMe; n = 1 or 2) was investigated under bulk conditions. Catalytic activity of the zirconocenes, and molecular weight and isotacticity of polypropylenes are found to be dependent on the position and number of the Lewis base functional groups in the zirconocenes. All the crude polypropylenes possess a broad molecular weight distribution and multi-melting transitions, indicating an involvement of multi-catalytic active species in the polymerization. The highest [mmmm] value of an isotactic portion of the polypropylenes reached 89%, which is higher than that (85%) from the well-known $C_2$-symmetric EBIZr (rac-$Et(Ind)_2ZrCl_2$) catalyst. These results support that the in situ generated, rigid rac-like cation-anion pair through the Lewis acid-base interactions between the functional groups of zirconocenes and methylaluminoxane anion is effective in the formation of isotactic polypropylene under bulk propylene polymerization conditions.

Ara - C유도체의 항암작용에 관한 연구 (1) : 암세포에 대한 Ara-C 유도체의 항암효과에 대한 in vivo 연구

  • Lee, Hyung-Hwan;Cho, Dong-In;Ji, Yong-Hoon;Lee, Chul-Kyu;Kang, Heon;Choi, Hee-Baek;Lee, Hye-Yeol;Kim, Eun-Tae;Kanter, P.M.;Creaven, P.J.;West, C.R.
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1994.04a
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    • pp.199-199
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    • 1994
  • Thioglycerol과 glycerol로부터 rac-1-S-octa-decyl-2-O-palmitoyl-1-S-thioglycerol-3-phosphate (DL -PTBA-P)와 rac-1-O-octadecyl-2-O-palmitoyl-g1ycerol-3-phosphate (DL-PBA-P)등을 합성하였고, 이들에 ara-C 유도체인 ara-CMP morpholidate를 반응시켜 최종 산물인 ara-CDP-DL-PCA, ara-CDP-DL-PBA, ara-CDP-DL-PTCA 및 ara-CDP-DL-PTBA등을 합성하였다. 이들 최종산믈의 항암효과는 L1210 lymphoid leukemia, colon 26 carcioma, M5076 sarcoma, C-1300 neuroblastoma, 3-Lewis lung carcinoma, WEHI-3B leukemia, human colon cancer, hum an pancreatic cancer 등의 암세포주를 사용하여 실험하였다. L1210를 DB/2J의 뇌막 또는 복강, DBA/1J의 복강내에 이식하여 ara-C, Ehss thioether lipid의 ara-C 유도체 (ara-CDP-L-DP, ara-CDP-DL-PCA, ara-CDP-DL-PBA, ara -CDP-DL-PTCA, ara-CDP-D-PTBA, ara-CDP-L-PTBA, ara-CDP-DL-PTBA)를 단일 투여 또는 중복 투여하였고, 3-Lewis는 C57BL/6 의 발바닥 피하, colon26은 BALB/C의 견갑상부 히아조직, M5076은 C57BL/6의 피하, WEHI-3B는 BALB/C의 복강, C-1300는 A/strong Ros에 각각 이식한 후 ara-C 또는 ara-CDP-DL-PTBA를 단일 또는 중복 투여하였다.

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