• Title/Summary/Keyword: switch cell

Search Result 350, Processing Time 0.026 seconds

TRAIL Based Therapy: Overview of Mesenchymal Stem Cell Based Delivery and miRNA Controlled Expression of TRAIL

  • Attar, Rukset;Sajjad, Farhana;Qureshi, Muhammad Zahid;Tahir, Fizza;Hussain, Ejaz;Fayyaz, Sundas;Farooqi, Ammad Ahmad
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.15 no.16
    • /
    • pp.6495-6497
    • /
    • 2014
  • Rapidly increasing number of outstanding developments in the field of TRAIL mediated signaling have revolutionized our current information about inducing and maximizing TRAIL mediated apoptosis in resistant cancer cells. Data obtained with high-throughput technologies have provided finer resolution of tumor biology and now it is known that a complex structure containing malignant cells strictly coupled with a large variety of surrounding cells constitutes the tumor stroma. Utility of mesenchymal stem cells (MSCs) as cellular vehicles has added new layers of information. There is sufficient experimental evidence substantiating efficient gene deliveries into MSCs by retroviral, lentiviral and adenoviral vectors. Moreover, there is a paradigm shift in molecular oncology and recent high impact research has shown controlled expression of TRAIL in cancer cells on insertion of complementary sequences for frequently downregulated miRNAs. In this review we have attempted to provide an overview of utility of TRAIL engineered MSCs for effective killing of tumor and potential of using miRNA response elements as rheostat like switch to control expression of TRAIL in cancer cells.

High-Frequency Flyback Transformer Linked PWM Power Conditioner with An Active Switched Capacitor Snubber

  • Mun, Sang-Pil;Kim, Soo-Wook;Joo, Seok-Min;Park, Young-Jun
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.22 no.7
    • /
    • pp.7-15
    • /
    • 2008
  • A single active capacitor snubber-assisted soft-switching sinewave pulse modulation utility-interactive power conditioner with a three-winding flyback high frequency transformer link and a bidirectional active power switch in its secondary side has been proposed. With the aid of the switched-capacitor quasi-resonant snubber cell, the high frequency switching devices in the primary side of the proposed DC-to-AC sinewave power inverter can be turned-off with ZVS commutation. In addition to this, the proposed power conditioner in the DCM can effectively take the advantages of ZCS turn-on commutation. Its output port is connected directly to the utility AC power source grid. At the end, the prototype of the proposed HF-UPC is built and tested in experiment. Its power conversion conditioning and processing circuit with a high frequency flyback transformer link is verified and the output sinewave current is qualified in accordance with the power quality guidelines of the utility AC interactive power systems.

Handover Control for WCDMA Femtocell Networks

  • Chowdhury, Mostafa Zaman;Jang, Yeong-Min
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.35 no.5B
    • /
    • pp.741-752
    • /
    • 2010
  • The ability to seamlessly switch between the macro networks and femtocell networks is a key driver for femtocell network deployment. The handover procedures for the integrated femtocell/macrocell networks differ from the existing handovers. Some modifications of existing network and protocol architecture for the integration of femtocell networks with the existing macrocell networks are also essential. These modifications change the signal flow for handover procedures due to different 2-tier cell (macrocell and femtocell) environment. The handover between two networks should be performed with minimum signaling. A frequent and unnecessary handover is another problem for hierarchical femtocell/macrocell network environment that must be minimized. This work studies the details mobility management schemes for small and medium scale femtocell network deployment. To do that, firstly we present two different network architectures for small scale and medium scale WCDMA femtocell deployment. The details handover call flow for these two network architectures and CAC scheme to minimize the unnecessary handovers are proposed for the integrated femtocell/macrocell networks. The numerical analysis for the proposed M/M/N/N queuing scheme and the simulation results of the proposed CAC scheme demonstrate the handover call control performances for femtocell environment.

Current-Voltage Characteristics of Molecular Electronic Devices Using a Amino-Style Derivatives (Amino-style 유도체를 이용한 분자 전자 소자의 전류-전압 특성에 관한 연구)

  • Kim, So-Young;Koo, Ja-Ryong;Kim, Young-Kwan
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2004.07b
    • /
    • pp.882-885
    • /
    • 2004
  • Organic molecules have many properties that make them attractive for electronic applications. We have been examining the progress of memory cell by using molecular-scale switch to give an example of the application using both nanoscale components and Si-technology. In this study, molecular electronic devices were fabricated with amion style derivatives as redox-active component to compare to the devices using Zn-Porphyrin derivatives. This molecule is amphiphilic to allow monolayer formation by the Langmuir-Blodgett (LB) method, and then this LB monolayer is inserted between two metal electrodes. According to current-voltage (I-V) characteristics, it was found that the devices show remarkable hysteresis behavior and can be used as memory devices at ambient conditions, when aluminum oxide layer was existed on bottom electrode. Diode-like characteristics were measured only, when Pt layer was existed as bottom electrode. It was also found that this metal layer interacts with the organic molecules and acts as a protecting layer, when thin Ti layer was inserted between the organic molecular layer and the top Al electrode. These electrical properties of the devices may be applicable to active components for the memory and/or logic gates in the future.

  • PDF

Multi-Central System for Large Scale PV Power Generation (대용량 태양광 발전용 멀티센트럴 시스템)

  • Park, Jong-Hyoung;Ko, Kwang-Soo;Kim, Heung-Geun;Nho, Eui-Cheol;Chun, Tae-Won
    • 한국태양에너지학회:학술대회논문집
    • /
    • 2012.03a
    • /
    • pp.427-432
    • /
    • 2012
  • This paper proposes efficient operation method of PV system consisted of multi-central which is suitable for large scale system. The multi-central system used switch at a DC-link and applied proposed algorithm can improve the efficiency and the reliability on the existing system. This algorithm, with advantage of Multi-Central system can minimize the effect of different characteristic of each PV array due to a shadow or damaged PV cell. Each system is analysed and maximum power point tracking control, DC-link voltage control and output current control is used commonly. The validity is verified after comparing of the existing system and proposed system by simulation.

  • PDF

The Study on Algorithm for Partial shade Compasation of PV (태양광 발전시스템의 부분그늘 보상을 위한 알고리즘에 관한 연구)

  • Koh K. H.;Lee H. W.;Suh K. Y.;Koh H. S.;Moon S. C.
    • Proceedings of the KIPE Conference
    • /
    • 2003.11a
    • /
    • pp.271-274
    • /
    • 2003
  • In this paper, compare and analyze existent MPPT algorithms. Existent algorithms have defects which don't generate it in a partial shade or low insolation. Therefore, to supplement it, we design improved IncCond algorithm consisted of a Aux. switch and capacitor with Generation Control circuit which can always obtain maximum generation power at the factor which is reduced generational efficiency by partial shade. Generation Control circuit is method which can always get maximum output power as it regularly controls each voltage of serial connected solar cell. Accordingly, it can improve efficiency and confidence of utility interaction inverter. Construction of system use a low price PIC16F87X. We analyze special character according to system operation through simulation and prove the validity through experiments.

  • PDF

Cloning and characterization of ADP-ribosylation factor 1b from the olive flounder Paralichthys olivaceus

  • Son, So-Hee;Jang, Jin-Hyeon;Jo, Hyeon-Kyeong;Chung, Joon-Ki;Lee, Hyung-Ho
    • Fisheries and Aquatic Sciences
    • /
    • v.20 no.6
    • /
    • pp.10.1-10.7
    • /
    • 2017
  • Small GTPases are well known as one of the signal transduction factors of immune systems. The ADP-ribosylation factors (ARFs) can be classified into three groups based on the peptide sequence, protein molecular weight, gene structure, and phylogenetic analysis. ARF1 recruits coat proteins to the Golgi membranes when it is bound to GTP. The class I duplicated ARF gene was cloned and characterized from the olive flounder (Paralichthys olivaceus) for this study. PoARF1b contains the GTP-binding motif and the switch 1 and 2 regions. PoARF1b and PoARF1b mutants were transfected into a Hirame natural embryo cell to determine the distribution of its GDP/GTP-bound state; consequently, it was confirmed that PoARF1b associates with the Golgi body when it is in a GTP-binding form. The results of the qPCR-described PoARF1b were expressed for all of the P. olivaceus tissues. The authors plan to study the gene expression patterns of PoARF1b in terms of immunity challenges.

Design of 234.7 MHz Mixed Mode Frequency Multiplication & Distribution ASIC for ATM Switching System (ATM 교환기용 234.7 MHz 혼합형 주파수 체배분배 ASIC의 설계)

  • 채상훈;정희범
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.24 no.10A
    • /
    • pp.1597-1602
    • /
    • 1999
  • An analog / digital mixed mode frequency multiplication and distribution ASIC for switch link or network synchronization of ATM switching system for B-ISDN has designed. This ASIC generates 234-7 MHz system clock and 77.76 MHz, 19.44 MHz user clocks using 46.94 MHz external clock. It also includes digital circuits for checking and selecting between the two external clocks. For effective ASIC design, full custom technique is used in analog PLL circuit and standard cell based technique is used in digital circuit. Resistors and capacitors are specially designed so the chip can be implemented in 0.8$\mu\textrm{m}$ digital CMOS technology.

  • PDF

Mechanisms Underlying the Effects of LPS and Activation-induced Cytidine Deaminase on IgA Isotype Expression

  • Park, Seok-Rae;Kim, Hyun-A;Chun, Sung-Ki;Park, Jae-Bong;Kim, Pyeung-Hyeun
    • Molecules and Cells
    • /
    • v.19 no.3
    • /
    • pp.445-451
    • /
    • 2005
  • Activation-induced cytidine deaminase (AID) is needed for Ig class switch recombination (CSR). We explored the effect of LPS on the expression of AID during B cell differentiation, and the role of AID in IgA isotype expression. In normal spleen B cells, LPS increased AID transcription up to 48 h post-stimulation, i.e. around the time of Ig CSR. TGF-${\beta}1$ and AID were required for IgA expression, and LPS contributed to $TGF{\beta}1$-induced IgA production largely by inducing AID. Interestingly, LPS repressed AID transcription in $sIgA^+$ B cells but still stimulated IgA production mainly by increasing the rate of IgA secretion. Our data indicate that LPS contributes to $TGF{\beta}1$-induced IgA isotype expression in at least two ways: by stimulating AID transcription before CSR and by enhancing the IgA secretion rate after CSR.

Automatic Switching System for The Impedance Analysis of Multichannel icroelectrode Arrays: Limits and Improvement Scheme (다채널 미세전극칩 임피던스 분석을 위한 자동 스위칭 시스템: 한계점 및 개선 방안)

  • Lee, Seok-Young;Nam, Yoon-Key
    • Journal of Biomedical Engineering Research
    • /
    • v.32 no.3
    • /
    • pp.207-217
    • /
    • 2011
  • Electrode impedances are measured to quantitatively characterize the electrode-electrolyte or cell-electrode interfaces. In the case of high-density microelectrode arrays(MEAs) that have been developed for brainmachine interface applications, the characterization process becomes a repeating and time-consuming task; a system that can perform the measurement and analysis in an automated fashion with accuracy and speed is required. However, due to the large number of channels, parasitic capacitance and off-capacitance components of the switching system become the major factors that decreased the accuracy for the measurement of high impedance microelectrodes. Here we investigated the implementation of automatic impedance measurement system with analyzing the causes of possible measurement-related problems in multichannel switching configuration. Based on our multi-channel measurement circuit model, we suggest solutions to the problems and introduce a novel impedance measurement scheme using electro-mechanical relays. The implemented measurement system could measure |Z| < 700 $k{\Omega}$ of impedance in - 10% errors, which can be widely applicable to high density neural recording MEAs.