• Title/Summary/Keyword: signal cascade

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Tyrosine Phosphorylation of Paxillin during Cell Adhesion

  • Chang, Jong-Soo;Lee, Hong-Mie;Min, Do-Sik
    • BMB Reports
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    • v.33 no.4
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    • pp.349-352
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    • 2000
  • Proteins that are involved in cellular signal cascade experience phosphorylation and dephosphorylation cycles in their tyrosine residue(s) during cell adhesion. In order to identify the protein(s), which tyrosine desidues are specifically phosphorylated when the cells attached to the substrate, we compared the tyrosine phosphorylation level of proteins between suspension and adhered culture condition in rat fibroblast 3Yl cells. We found that a cluster of 70 kDa protein was specifically phosphorylated when the cells adhered to the substrate, but did not effect the cells held in suspension. The phosphorylated protein is identified as paxillin, a focal adhesion protein in immunoprecipitation and immunobloting analysis. These results suggest that the tyrosine phosphorylation of paxillin may play a role in cell-substrate adhesion.

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Mitogen-Activated Protein Kinase Kinase 3 Is Required for Regulation during Dark-Light Transition

  • Lee, Horim
    • Molecules and Cells
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    • v.38 no.7
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    • pp.651-656
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    • 2015
  • Plant growth and development are coordinately orchestrated by environmental cues and phytohormones. Light acts as a key environmental factor for fundamental plant growth and physiology through photosensory phytochromes and underlying molecular mechanisms. Although phytochromes are known to possess serine/threonine protein kinase activities, whether they trigger a signal transduction pathway via an intracellular protein kinase network remains unknown. In analyses of mitogen-activated protein kinase kinase (MAPKK, also called MKK) mutants, the mkk3 mutant has shown both a hypersensitive response in plant hormone gibberellin (GA) and a less sensitive response in red light signaling. Surprisingly, light-induced MAPK activation in wild-type (WT) seedlings and constitutive MAPK phosphorylation in dark-grown mkk3 mutant seedlings have also been found, respectively. Therefore, this study suggests that MKK3 acts in negative regulation in darkness and in light-induced MAPK activation during dark-light transition.

A Study on the Circuit Analysis of Composite BiCMOS Transistor and the Design Methodology of BiCMOS Differential Amplifier (복합 BiCMOS 트랜지스터의 회로 분석 및 그로 구성된 차동 증폭기의 설계기법에 관한 연구)

  • 송민규;김민규;박성진;김원찬
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.26 no.9
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    • pp.1359-1368
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    • 1989
  • In this paper, the composite BiCMOS transistor which combines a bipolar transistor and a MOS transistor in a cascade type, is analyzed in terms of I-V characteristics and small signal equivalent circuit. As a result, it has a larger driving capability than MOS transistor and a more extended rante of input voltage than bipolar transistor. Next, a BiCMOS differential amplifier as its application example is designed and compared with the CMOS one and the bipolar one. It increases the driving capability of the CMOS differential amp and improves the linear operation region of the bipolar differential amp.

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A Study on the construction of Broad-Band Twisted-Wire Quadrature Hybrid (광대역 Twisted-Wire Quadrature Hybrid 회로구성에 관한 연구)

  • 박정기;김성진
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.17 no.6
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    • pp.78-85
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    • 1980
  • A symmetrical 3-dB quadrature hybrid circuits, consisting mainly of bifilar pair of taitoted wires, is described. A cascade of two such hybrid circuits can achieve an octave bandwidth hybrid circuit with a small coupling loss. Since the proposed type is simple, compact, and low In cost 1 its applicarion may be preferred to the more common coaxial line or printed -circuit type hybrid version in the frequency region below 1 GHz. This study provides a design method for a hybrid circuit mixing two different antenna signals for the anti - ghosting of television signal.

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Vector Quantization of Image Signal using Larning Count Control Neural Networks (학습 횟수 조절 신경 회로망을 이용한 영상 신호의 벡터 양자화)

  • 유대현;남기곤;윤태훈;김재창
    • Journal of the Korean Institute of Telematics and Electronics C
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    • v.34C no.1
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    • pp.42-50
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    • 1997
  • Vector quantization has shown to be useful for compressing data related with a wide rnage of applications such as image processing, speech processing, and weather satellite. Neural networks of images this paper propses a efficient neural network learning algorithm, called learning count control algorithm based on the frquency sensitive learning algorithm. This algorithm can train a results more codewords can be assigned to the sensitive region of the human visual system and the quality of the reconstructed imate can be improved. We use a human visual systrem model that is a cascade of a nonlinear intensity mapping function and a modulation transfer function with a bandpass characteristic.

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Screening of the Extracts of Herbal Medicines which Stimulate the Hydrolysis of Phosphoinositides in Jurkat T-lymphocyte Cells (Jurkat T 면역세포에서 Phosphoinositides의 가수분해를 증가시키는 약용식물 추출물의 검색)

  • 민도식;이영한;백석환;서판길;류성호
    • Biomolecules & Therapeutics
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    • v.4 no.2
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    • pp.148-153
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    • 1996
  • Activation of the T lymphocytes results in a variety of early biochemical events ultimately leading to cell proliferation and lymphokine production. Stimulation of the signal transduction cascade in T cells through the T cell receptor coincides with activation of the phosphatidylinositol-phospholipase C (PI-PLC) pathway. Therefore, we have established a model system to screen immune-simulator that can increase the hydrolysis of phosphoinositides in human T cell leukemia Jurkat cells. As a result of screening from herbal medicine extract, 4 extracts (O1ibanum, Ephedrae Herba, Real Gar, Saussureae Radix) were found 14 increase the production of inositol phosphates. All the active fraction from the four kinds of extract were fluted in a different retention time on C-18 HPLC and these active fraction also showed difference in cell specificity. And all the active fractions increased DNA synthesis in T cell. Therefore, it is suggested that the active fraction among 4 extracts might contain a compound having different properties one another.

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Time Delay Prediction of Networked Control Systems using Cascade Structures of Fuzzy Neural Networks (종속형 퍼지 뉴럴 네트워크를 이용한 네트워크 제어 시스템의 시간 지연 예측)

  • Lee, Cheol-Gyun;Han, Chang-Wook
    • Journal of IKEEE
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    • v.23 no.3
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    • pp.899-903
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    • 2019
  • In networked control systems, time-varying delay of the transmitting signal is inevitable. If the transmission delay is longer than the fixed sampling time, the system will be unstable. To solve this problem, this paper proposes the method to predict the delay using logic-based fuzzy neural networks, and the predicted time delay will be used as a sampling time in the networked control systems. To verify the effectiveness of the proposed method, the delay data collected from the real system are used to train and test the logic-based fuzzy neural networks.

(-) 3,5-Dicaffeoyl-muco-quinic acid isolated from Aster scaber contributes to the differentiation of PC12 cells: through tyrosine kinase cascade signaling

  • Hur, Jin-Young;Lee, Pyeong-Jae;Kim, Ho-Cheol;Kang, In-Sug;Lee, Kang-Lo;Kim, Sun-Yeou
    • Proceedings of the PSK Conference
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    • 2003.10b
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    • pp.79.1-79.1
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    • 2003
  • Aster scaber T. (Asteraceae) has been used in traditional Korean and Chinese medicine to treat bruises, snakebites, headaches and dizziness. (-) 3,5-Dicaffeoyl-muco-quinic acid (DQ) isolated from Aster scaber induced neurite outgrowth in PC12 cells. It has been reported that the activation of the extracellular signal regulated kinase1/2 (Erk 1/2) and phosphoinositide 3 (P13) kinase plays a crucial role in the NGF-induced differentiation of PC12 cells. This study showed that the effect of DQ on neurite outgrowth is mediated via the Erk 1/2 and PI3 kinase-dependent pathways like NGF. (omitted)

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A New High-Efficiency CMOS Darlington-Pair Type Bridge Rectifier for Driving RFID Tag Chips (RFID 태그 칩 구동을 위한 새로운 고효율 CMOS 달링턴쌍형 브리지 정류기)

  • Park, Kwang-Min
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.4
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    • pp.1789-1796
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    • 2012
  • In this paper, a new high-efficiency CMOS bridge rectifier for driving RFID tag chips is designed and analyzed. The input stage of the proposed rectifier is designed as a cascade structure connected with two NMOSs for reducing the gate capacitance by circuitry method, which is the main path of the leakage current that is increased when the operating frequency is increased. This gate capacitance reduction technique using the cascade input stage for reducing the gate leakage current is presented theoretically. The output characteristics of the proposed rectifier are derived analytically using its high frequency small-signal equivalent circuit. For the general load resistance of $50K{\Omega}$, the proposed rectifier shows better power conversion efficiencies of 28.9% for 915MHz UHF (for ISO 18000 -6) and 15.3% for 2.45GHz microwave (for ISO 18000-4) than those of 26.3% and 26.8% for 915MHz, and 13.2% and 12.6% for 2.45GHz of compared other two existing rectifiers. Therefore, the proposed rectifier may be used as a general purpose rectifier to drive tag chips for various RFID systems.

The Incremental Delta-Sigma ADC for A Single-Electrode Capacitive Touch Sensor (단일-극 커패시터 방식의 터치센서를 위한 Incremental 델타-시그마 아날로그-디지털 변환기 설계)

  • Jung, Young-Jae;Roh, Jeong-Jin
    • Journal of IKEEE
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    • v.17 no.3
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    • pp.234-240
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    • 2013
  • This paper presents an incremental delta-sigma analog-to-digital converter (ADC) for a single-electrode capacitive touch sensor. The second-order cascade of integrators with distributed feedback (CIFB) delta-sigma modulator with 1-bit quantization was fabricated by a $0.18-{\mu}m$ CMOS process. In order to achieve a wide input range in this incremental delta-sigma analog-to-digital converter, the shielding signal and the digitally controlled offset capacitors are used in front of a converter. This circuit operated at a supply voltage of 2.6 V to 3.7 V, and is suitable for single-electrode capacitive touch sensor for ${\pm}10-pF$ input range with sub-fF resolution.