• 제목/요약/키워드: direct regulation

검색결과 489건 처리시간 0.033초

Molecular Mechanisms of Generation for Nitric Oxide and Reactive Oxygen Species, and Role of the Radical Burst in Plant Immunity

  • Yoshioka, Hirofumi;Asai, Shuta;Yoshioka, Miki;Kobayashi, Michie
    • Molecules and Cells
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    • 제28권4호
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    • pp.321-329
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    • 2009
  • Rapid production of nitric oxide (NO) and reactive oxygen species (ROS) has been implicated in the regulation of innate immunity in plants. A potato calcium-dependent protein kinase (StCDPK5) activates an NADPH oxidase StRBOHA to D by direct phosphorylation of N-terminal regions, and heterologous expression of StCDPK5 and StRBOHs in Nicotiana benthamiana results in oxidative burst. The transgenic potato plants that carry a constitutively active StCDPK5 driven by a pathogen-inducible promoter of the potato showed high resistance to late blight pathogen Phytophthora infestans accompanied by HR-like cell death and $H_2O_2$ accumulation in the attacked cells. In contrast, these plants showed high susceptibility to early blight necrotrophic pathogen Alternaria solani, suggesting that oxidative burst confers high resistance to biotrophic pathogen, but high susceptibility to necrotrophic pathogen. NO and ROS synergistically function in defense responses. Two MAPK cascades, MEK2-SIPK and cytokinesis-related MEK1-NTF6, are involved in the induction of NbRBOHB gene in N. benthamiana. On the other hand, NO burst is regulated by the MEK2-SIPK cascade. Conditional activation of SIPK in potato plants induces oxidative and NO bursts, and confers resistance to both biotrophic and necrotrophic pathogens, indicating the plants may have obtained during evolution the signaling pathway which regulates both NO and ROS production to adapt to wide-spectrum pathogens.

MTA1 Overexpression Induces Cisplatin Resistance Innasopharyngeal Carcinoma by Promoting Cancer Stem Cells Properties

  • Feng, Xiaohua;Zhang, Qianbing;Xia, Songxin;Xia, Bing;Zhang, Yue;Deng, Xubin;Su, Wenmei;Huang, Jianqing
    • Molecules and Cells
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    • 제37권9호
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    • pp.699-704
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    • 2014
  • Themetastasis-associated gene 1 (MTA1) oncogene hasbeen suggested to be involved in the regulation of cancer progression. However, there is still no direct evidence that MTA1 regulates cisplatin (CDDP) resistance, as well as cancer stem cell properties. In this study, we found that MTA1 was enriched in CNE1/CDDP cells. Knock down of MTA1 in CNE1/CDDP cells reversed CSCs properties and CDDP resistance. However, ectopic expression of MTA1 in CNE1 cells induced CSCs phenotypes and CDDP insensitivity. Interestingly, ectopic overexpression of MTA1-induced CSCs properties and CDDP resistance were reversed in CNE1 cells after inhibition of PI3K/Akt by LY294002. In addition, MTA1 expression and Akt activity in CNE1/CDDP cells was much higher than that in CNE1 cells. These results suggested that MTA1 may play a critical role in promoting CDDP resistance in NPC cells by regulatingcancer stem cell properties via thePI3K/Akt signaling pathway. Our findings suggested that MTA1 may be a potential target for overcoming CDDP resistance in NPC therapy.

부분 예혼합 압축착화 연소기법을 적용한 HSDI 디젤엔진의 배기 성능 개선 (Improvement of Emission Performances of a HSDI Diesel Engine with Partial Premixed Compression Ignition Combustion Method)

  • 정재우;강정호;김남호;민경덕;이기형;이정훈;김현옥;강우
    • 한국자동차공학회논문집
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    • 제16권6호
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    • pp.88-96
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    • 2008
  • Currently, due to the serious world-wide air pollution by substances emitted from vehicles, emission control is enforced more firmly and it is expected that the regulation requirements for emission will become more severe. A new concept combustion technology that can reduce the NOx and PM in relation to combustion is urgently required. This study used a split injection method at a 4 cylinder common-rail direct injection diesel engine in order to apply the partially premixed charge compression ignition combustion method without significantly altering engine specifications And it is investigated that the effects of the injection ratio and SCV(swirl control valve) to emission characteristics. From these tests, soot(g) and NOx(g) emission could be reduced to 40% and 92% compared to base engine performance at specified engine driving conditions(6 points with weight factors) according to application of split injection and SCV(swirl control valve).

환경정책수단의 최적성에 대한 이론적 검토 (A Theoretical Study on the Optimal Environmental Policy Instruments)

  • 권오성
    • 자원ㆍ환경경제연구
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    • 제12권3호
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    • pp.397-425
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    • 2003
  • 본 연구는 Uzawa(1965)-Lucas(1988) 유형의 내생적 경제성장모형에 환경변수를 도입하여 개발한 이론적 모형을 사용하여 시장경제에서 어떠한 환경정책수단이 사회 최적을 실현할 수 있는지의 여부를 시험하였다. 대부분의 기존연구에서는 환경정책수단의 효과성을 평가함에 있어서 비용효율성(cost efficiency)에 초점을 맞추고 있는 반면, 본 연구는 거시경제학에서 사용되는 정교한 경제성장모형을 이용하여 최적성(optimality)을 연구한다는 데 기존연구와 가장 큰 차이점이 있다고 할 수 있다. 일반균형분석을 통해 환경정책수단의 최적성에 대해 검토한 결과, 정태모형에서는 차이가 없지만 동태모형에서 환경세, 배출거래권제도 등의 경제적 유인수단은 사회 최적을 실현하지만, 특정 형태의 직접규제는 사회최적을 이룰 수 없음을 보여주고 있다. 그 이유는 환경세나 배출거래권제도는 환경의 질에 대하여 독립된 시장가격을 부여함으로써 물적자본과 인적자본의 배분에 영향을 미치는 반면, 직접규제는 환경의 질에 대한 시장가격을 반영하지 않아 자본의 가치가 왜곡되기 때문인 것으로 나타났다.

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Murrayafoline A Induces a G0/G1-Phase Arrest in Platelet-Derived Growth Factor-Stimulated Vascular Smooth Muscle Cells

  • Han, Joo-Hui;Kim, Yohan;Jung, Sang-Hyuk;Lee, Jung-Jin;Park, Hyun-Soo;Song, Gyu-Yong;Nguyen, Manh Cuong;Kim, Young Ho;Myung, Chang-Seon
    • The Korean Journal of Physiology and Pharmacology
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    • 제19권5호
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    • pp.421-426
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    • 2015
  • The increased potential for vascular smooth muscle cell (VSMC) growth is a key abnormality in the development of atherosclerosis and post-angioplasty restenosis. Abnormally high activity of platelet-derived growth factor (PDGF) is believed to play a central role in the etiology of these pathophysiological situations. Here, we investigated the anti-proliferative effects and possible mechanism(s) of murrayafoline A, a carbazole alkaloid isolated from Glycosmis stenocarpa Guillamin (Rutaceae), on PDGF-BB-stimulated VSMCs. Murrayafoline A inhibited the PDGF-BB-stimulated proliferation of VSMCs in a concentration-dependent manner, as measured using a non-radioactive colorimetric WST-1 assay and direct cell counting. Furthermore, murrayafoline A suppressed the PDGF-BB-stimulated progression through $G_0/G_1$ to S phase of the cell cycle, as measured by [$^3H$]-thymidine incorporation assay and cell cycle progression analysis. This anti-proliferative action of murrayafoline A, arresting cell cycle progression at $G_0/G_1$ phase in PDGF-BB-stimulated VSMCs, was mediated via down-regulation of the expression of cyclin D1, cyclin E, cyclin-dependent kinase (CDK)2, CDK4, and proliferating cell nuclear antigen (PCNA), and the phosphorylation of retinoblastoma protein (pRb). These results indicate that murrayafoline A may be useful in preventing the progression of vascular complications such as restenosis after percutaneous transluminal coronary angioplasty and atherosclerosis.

Roles of Metabotropic Glutamate Receptors 1 and 5 in Rat Medial Vestibular Nucleus Neurons

  • Lee, Hae-In;Lee, Sung-Hyo;Chun, Sang-Woo
    • International Journal of Oral Biology
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    • 제36권2호
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    • pp.71-78
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    • 2011
  • Using whole cell current- and voltage-clamp recording we investigated the characteristics and pharmacology of group I metabotropic glutamate receptor (mGluR)-mediated responses in rat medial vestibular nucleus (MVN) neurons. In current clamp conditions, activation of mGluR I by application of the group I mGluR agonist (R,S)-3,5-dihydroxyphenylglycine (DHPG) induced a direct excitation of MVN neurons that is characterized by depolarization and increased spontaneous firing frequency. To identify which of mGluR subtypes are responsible for the various actions of DHPG in MVN, we used two subtype-selective antagonists. (S)-(+)- alpha-amino-a-methylbenzeneacetic acid (LY367385) is a potent competitive antagonist that is selective for mGluR1, whereas 2-methyl-6-(phenylethynyl)-pyridine (MPEP) is a potent noncompetitive antagonist that is selective for mGluR5. In voltage clamp conditions, DHPG application increased the frequency of spontaneous and miniature inhibitory postsynaptic currents (IPSCs) but had no effect on amplitude distributions. Antagonism of the DHPG-induced increase of miniature IPSCs required the blockade of both mGluR1 and mGluR5. DHPG application induced an inward current, which can be enhanced under depolarized conditions. DHPG-induced current was blocked by LY367385, but not by MPEP. Both LY367385 and MPEP antagonized the DHPG-induced suppression of the calcium activated potassium current ($I_{AHP}$). These data suggest that mGluR1 and mGluR5 have similar roles in the regulation of the excitability of MVN neurons, and show a little distinct. Furthermore, mGluR I, via pre- and postsynaptic actions, have the potential to modulate the functions of the MVN.

추나의학 관련과목 개설현황 조사 (Curriculum Analysis of Chuna Manual Medicine in Korea)

  • 박태용;신병철
    • 척추신경추나의학회지
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    • 제5권1호
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    • pp.157-168
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    • 2010
  • Objectives: The aim of this study was to investigate the curriculum of Chuna manual medicine (CMM)-related subjects in oriental medicine college and to let CMM have opportunities to develope current curriculum and basic circumstance for CMM. Methods: Questionnaire was obtained from 11 oriental medicine college and 1 school of Korean medicine, Pusan National University, bye-mail. If there was any insufficient information from response, we asked more information by direct call. Results and Conclusions: The findings from our study can be summarized as follows: 1. There are three CMM-related subjects, CMM, Oriental Rehabilitation Medicine (ORM) and Neuromusculoskeletology(NMS). All curriculums of 8 colleges belonged to classification I have CMM and DRM courses. Curriculums of 4 colleges belonged to classification II, have ORM or NMS course without CMM course. 2. 10 colleges of 11 ones which have ORM course, have major compulsory courses, 1 college has a major optional course. 5 colleges of 8 ones which have CMM course, have major compulsory courses, 3 colleges have major optional courses. 2 colleges have only part-time lecturers for CMM course, other 2 college have cooperation of specialized professors and part-time lecturers, another 8 colleges have only specialized professors. 3. Most CMM-related subjects is teached at 3 or 4 grade of medical course. The units taken for CMM-related subjects is minimum 4 units to maximum 8 units in total about 160 units. 4. Total class hour for CMM-related subjects is minimum 120 hours to maximum 225 hours, and practice hours is about minimum 30 hours to maximum 75 hours. 5. The systematic regulation and financial support is needed for patients to get the best CMM treatment, because the present curriculum of CMM is insufficient for carrying out the best manual therapy for patients.

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국제중재에서 국제적 강행법규의 적용가능성 (Applicability of Overriding Mandatory Rules in International Arbitration)

  • 정홍식
    • 한국중재학회지:중재연구
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    • 제23권4호
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    • pp.3-27
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    • 2013
  • Overriding Mandatory rules are laws that purport to apply irrespective of the law chosen by the parties to govern their contractual relations. This article examines their role and applicability in international arbitration. The overriding mandatory rules pose a complex and continuing problem for arbitrators because they put the interests of states and parties in direct competition. When a law says that arbitrators must apply it, yet the parties' contract excludes it, what should the arbitrators do? Where should their allegiance lie? The answer depends on the underlying nature of arbitration - and since that can be legitimately conceptualized in different ways, a principled approach to overriding mandatory rules seems to be impossible to provide. Nevertheless, a practical solution is required, because there were European cases in which courts voided valid arbitration agreements made, reasoning that arbitrators certainly would not apply and/or take into account its overriding mandatory rules of indemnity right granted to commercial agent and distributor in Europe. Therefore, this paper first examines status of overriding mandatory rules of another law in international litigation and then explores any possibility of application of overriding mandatory rules of another law in international commercial arbitration. With this analysis, the author reaches into a conclusion that the arbitrator should and/or take into account overriding mandatory rules of another law, yet should limit to them of the country where characteristic performance is made under the contract.

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DDX53 Promotes Cancer Stem Cell-Like Properties and Autophagy

  • Kim, Hyuna;Kim, Youngmi;Jeoung, Dooil
    • Molecules and Cells
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    • 제40권1호
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    • pp.54-65
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    • 2017
  • Although cancer/testis antigen DDX53 confers anti-cancer drug-resistance, the effect of DDX53 on cancer stem cell-like properties and autophagy remains unknown. MDA-MB-231 ($CD133^+$) cells showed higher expression of DDX53, SOX-2, NANOG and MDR1 than MDA-MB-231 ($CD133^-$). DDX53 increased in vitro self-renewal activity of MCF-7 while decreasing expression of DDX53 by siRNA lowered in vitro self-renewal activity of MDA-MB-231. DDX53 showed an interaction with EGFR and binding to the promoter sequences of EGFR. DDX53 induced resistance to anti-cancer drugs in MCF-7 cells while decreased expression of DDX53 by siRNA increased the sensitivity of MDA-MB-231 to anti-cancer drugs. Negative regulators of DDX53, such as miR-200b and miR-217, increased the sensitivity of MDA-MB-231 to anti-cancer drugs. MDA-MB-231 showed higher expression of autophagy marker proteins such as ATG-5, $pBeclin1^{Ser15}$ and LC-3I/II compared with MCF-7. DDX53 regulated the expression of marker proteins of autophagy in MCF-7 and MDA-MB-231 cells. miR-200b and miR-217 negatively regulated the expression of autophagy marker proteins. Chromatin immunoprecipitation assays showed the direct regulation of ATG-5. The decreased expression of ATG-5 by siRNA increased the sensitivity to anti-cancer drugs in MDA-MB-231 cells. In conclusion, DDX53 promotes stem cell-like properties, autophagy, and confers resistance to anti-cancer drugs in breast cancer cells.

Coordinated Voltage Control Scheme for Multi-Terminal Low-Voltage DC Distribution System

  • Trinh, Phi Hai;Chung, Il-Yop;Kim, Taehoon;Kim, Juyong
    • Journal of Electrical Engineering and Technology
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    • 제13권4호
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    • pp.1459-1473
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    • 2018
  • This paper focuses on voltage control schemes for multi-terminal low-voltage direct current (LVDC) distribution systems. In a multi-terminal LVDC distribution system, there can be multiple AC/DC converters that connect the LVDC distribution system to the AC grids. This configuration can provide enhanced reliability, grid-supporting functionality, and higher efficiency. The main applications of multi-terminal LVDC distribution systems include flexible power exchange between multiple power grids and integration of distributed energy resources (DERs) using DC voltages such as photovoltaics (PVs) and battery energy storage systems (BESSs). In multi-terminal LVDC distribution systems, voltage regulation is one of the most important issues for maintaining the electric power balance between demand and supply and providing high power quality to end customers. This paper focuses on a voltage control method for multi-terminal LVDC distribution system that can efficiently coordinate multiple control units, such as AC/DC converters, PVs and BESSs. In this paper, a control hierarchy is defined for undervoltage (UV) and overvoltage (OV) problems in LVDC distribution systems based on the control priority between the control units. This paper also proposes methods to determine accurate control commands for AC/DC converters and DERs. By using the proposed method, we can effectively maintain the line voltages in multi-terminal LVDC distribution systems in the normal range. The performance of the proposed voltage control method is evaluated by case studies.