• Title/Summary/Keyword: trapping mechanism

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Oxidized LDL induces phosphorylation of non-muscle myosin IIA heavy chain in macrophages

  • Park, Young Mi
    • BMB Reports
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    • v.48 no.1
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    • pp.48-53
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    • 2015
  • Oxidized LDL (oxLDL) performs critical roles in atherosclerosis by inducing macrophage foam cell formation and promoting inflammation. There have been reports showing that oxLDL modulates macrophage cytoskeletal functions for oxLDL uptake and trapping, however, the precise mechanism has not been clearly elucidated. Our study examined the effect of oxLDL on non-muscle myosin heavy chain IIA (MHC-IIA) in macrophages. We demonstrated that oxLDL induces phosphorylation of MHC-IIA (Ser1917) in peritoneal macrophages from wild-type mice and THP-1, a human monocytic cell line, but not in macrophages deficient for CD36, a scavenger receptor for oxLDL. Protein kinase C (PKC) inhibitor-treated macrophages did not undergo the oxLDL-induced MHC-IIA phosphorylation. Our immunoprecipitation revealed that oxLDL increased physical association between PKC and MHC-IIA, supporting the role of PKC in this process. We conclude that oxLDL via CD36 induces PKC-mediated MHC-IIA (Ser1917) phosphorylation and this may affect oxLDL-induced functions of macrophages involved in atherosclerosis.

Effects of Carcinogens and Partial Hepatectomy on the Nitrogen Utilizing and the Xenobiotic Metabolizing Enzymes in the Hepatic Tissues of Rats (발암원과 부분간절제술 처리에 의한 백서 간 조직중 질소이용계 및 이물질 대사계 효소의 변화)

  • 박상철;김응국;곽상준;이건욱;김수태
    • Environmental Mutagens and Carcinogens
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    • v.8 no.1
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    • pp.22-34
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    • 1988
  • The biochemical changes of the hepatic tissues, induced by the carcinogen treatment such as diethylnitrosamine and acetamidofluorene in combination with the partial hepatectomy after Solt and Farber, were determined for the characterization of the induction of the proliferative capacity and the environmental adaptability of the carcinogenic tissues during the malignant transformation process. For the study of the proliferative capacity of the tissues, the activities of the enzymes, related with the nitrogen trapping mechanism, such as glutamine synthetase and gamma-glutamyltranspeptidase, were monitroed, while the cintents of cytochrome P450's and their isozymic patterns as well as the activities of the glutathione S-transferase were determined in the function of time after the hepatocarcinogenic stimuli.

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Effects of Electrical Stress on Polysilicon TFTs with Hydrogen passivation (다결정 실리콘 박막 트랜지스터의 수소화에 따른 전기적 스트레스의 영향)

  • Hwang, Seong-Soo;Hwang, Han-Wook;Kim, Dong-Jin;Kim, Yong-Sang
    • Proceedings of the KIEE Conference
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    • 1998.07d
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    • pp.1315-1317
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    • 1998
  • We have investigated the effects of electrical stress on poly-Si TFTs with different hydrogen passivation conditions. The amounts of threshold voltage shift of hydrogen passivated poly-Si TFTs are much larger than those of as-fabricated devices both under the gate bias stressing and under the gate and drain bias stressing. Also, we have quantitatively analized the degradation phenomena using by analytical method. we have suggested that the electron trapping in the gate dielectric is the dominant degradation mechanism in only gate bias stressed poly-Si TFT while the creation of defects in the poly-Si is prevalent in gate and drain bias stressed device.

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Light Effects on the Bias Stability of Transparent ZnO Thin Film Transistors

  • Shin, Jae-Heon;Lee, Ji-Su;Hwang, Chi-Sun;KoPark, Sang-Hee;Cheong, Woo-Seok;Ryu, Min-Ki;Byun, Chun-Won;Lee, Jeong-Ik;Chu, Hye-Yong
    • ETRI Journal
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    • v.31 no.1
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    • pp.62-64
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    • 2009
  • We report on the bias stability characteristics of transparent ZnO thin film transistors (TFTs) under visible light illumination. The transfer curve shows virtually no change under positive gate bias stress with light illumination, while it shows dramatic negative shifts under negative gate bias stress. The major mechanism of the bias stability under visible illumination of our ZnO TFTs is thought to be the charge trapping of photo-generated holes at the gate insulator and/or insulator/channel interface.

A Review of Corrosion and Hydrogen Diffusion Behaviors of High Strength Pipe Steel in Sour Environment

  • Kim, Sung Jin;Kim, Kyoo Young
    • Journal of Welding and Joining
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    • v.32 no.5
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    • pp.13-20
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    • 2014
  • A brief overview is given of the corrosion and hydrogen diffusion behaviors of high strength pipe steel in sour environment. Firstly, hydrogen adsorption and diffusion mechanism of the pipe steel is introduced. Secondly, the effect of iron sulfide film precipitated as a result of the corrosion reaction on the steel surface on hydrogen reduction reaction and subsequent hydrogen permeation through the steel is discussed. Moreover, the hydrogen diffusion behavior of the pipe steel under tensile stress in both elastic and plastic ranges is reviewed based on a number of experimental permeation data and theoretical models describing the hydrogen diffusion and trapping phenomena in the steel. It is hoped that this paper will result in significant academic contributions in the field of corrosion and hydrogen related problems of the pipe steel used in sour environment.

A study of electrical stress on short channel poly-Si thin film transistors (짧은 채널 길이의 다결정 실리콘 박막 트랜지스터의 전기적 스트레스에 대한 연구)

  • 최권영;김용상;한민구
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.32A no.8
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    • pp.126-132
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    • 1995
  • The electrical stress of short channel polycrystalline silicon (poly-Si) thin film transistor (TFT) has been investigated. The device characteristics of short channel poly-Si TFT with 5$\mu$m channel length has been observed to be significantly degraded such as a large shift in threshold voltage and asymmetric phenomena after the electrical stress. The dominant degradation mechanism in long channel poly-Si TFT's with 10$\mu$m and 20$\mu$m channel length respectively is charage trappling in gate oxide while that in short channel device with 5.mu.m channel length is defect creation in active poly-Si layer. We propose that the increased defect density within depletion region near drain junction due to high electric field which could be evidenced by kink effect, constitutes the important reason for this significant degradation in short channel poly-Si TFT. The proposed model is verified by comparing the amounts of the defect creation and the charge trapping from the strechout voltage.

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Occurrence Mechanism of Magnetic Properties in BiSrCaCuO Superconductor (산화물 초전도체의 자기적 특성 발생 메커니즘)

  • Lee, Sang-Heon
    • Journal of Powder Materials
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    • v.13 no.6 s.59
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    • pp.439-444
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    • 2006
  • An electromagnetic properties in BiSrCaCuO superconductor were studied. In the measurement of current-voltage properties, the voltage was measured when applying an external magnetic field. The voltage continues to appear after the removal of the magnetic field. This phenomenon was considered as a nonvolatile magnetic effect. The voltage increased with the applied magnetic flux, but it became constant at about $10^{-2}$T. The appearance of the voltage was ascribed to the trapping of magnetic flux.

Intensity-dependent dynamics of photoinduced absorption in CdS0.4/Se0.6 semiconductor doped glasses

  • Seo, Jung-Chul;Kim, Dong-Ho;Kong, Hong-Jin
    • Journal of the Optical Society of Korea
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    • v.1 no.1
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    • pp.15-18
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    • 1997
  • Intensity dependent dynamics of photoinduced absorption in $CdS_{0.4}$/$Se_{0.6}$ semiconductor doped glasses below the band gap was investigated by using time-resolved differential transmittance spectroscopy. The carriers populated through ultrafast trapping at semiconductor-glass interfaces give rise to a broad photoinduced absorption below the band gap. The decay time of transient absorption depends strongly on the excitation intensity. Based on our results, the physical mechanism for photoinduced absorption processes was suggested.

Nonlinear evolution of the relativistic Weibel instability driven by anisotropic temperature

  • Kaang, Helen H.;Mo, Chang
    • Bulletin of the Korean Space Science Society
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    • 2009.10a
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    • pp.34.2-34.2
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    • 2009
  • The relativistic Weibel instability has drawn attention as a main mechanism of the magnetic generation in the core of galaxies or in the formation of universe. The Weibel instability is not yet fully understood in the relativistic region. We investigated nonlinear saturation and decay of the relativistic Weibel instability. It is found that the early phase of the instability is in excellent agreement with the linear theory. But, an analysis based on an alternative magnetic trapping saturation theory reveals that a substantial discrepancy between the theory and simulation is revealed in the relativistic regime in contrast to an excellent agreement in the non-relativistic regime. The analysis of the Weibel instability beyond the quasilinear saturation stage shows an inverse cascade process via a nonlinear decay instability involving electrostatic fluctuation.

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Degradation of Gate Induced Drain Leakage(GIDL) Current of p-MOSFET along to Analysis Condition (분석 조건에 따른 p-MOSFET의 게이트에 유기된 드레인 누설전류의 열화)

  • 배지철;이용재
    • Electrical & Electronic Materials
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    • v.10 no.1
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    • pp.26-32
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    • 1997
  • The gate induced drain leakage(GIDL) current under the stress of worse case in -MOSFET's with ultrathin gate oxides has been measured and characterized. The GIDL current was shown that P-MOSFET's of the thicker gate oxide is smaller than that of the thinner gate oxide. It was the results that the this cur-rent is decreased with the increamental stress time at the same devices.It is analyzed that the formation components of GIDL current are both energy band to band tunneling at high gate-drain voltage and energy band to defect tunneling at low drain-gate voltage. The degradations of GIDL current was analyzed the mechanism of major role in the hot carriers trapping in gate oxide by on-state stress.

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