• 제목/요약/키워드: light activation

검색결과 360건 처리시간 0.029초

Association of Anti-apoptotic Mechanism Due to House Dust Mite in Neutrophils with Protein Synthesis and Bad

  • Kim, In Sik;Lee, Ji-Sook
    • 대한의생명과학회지
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    • 제22권4호
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    • pp.211-214
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    • 2016
  • House dust mite is an essential allergen in the pathogenesis of allergic diseases. Abnormal regulation of neutrophil apoptosis is an important pathogenic process in allergic diseases. In the present study, we investigated the effects of house dust mites on spontaneous apoptosis of neutrophils and its associated mechanisms. Extract of Dermatophagoides pteronissinus (DP) inhibited neutrophil apoptosis in a time-dependent manner. Cycloheximide (CHX), an inhibitor of translation, increased apoptosis of DP-treated neutrophils as well as control cells. The pro-apoptotic effect of CHX was blocked by DP in neutrophils. In addition, DP increased the phosphorylation of Bad in a time-dependent manner, indicating that it exerted an inhibitory effect on the function of Bad. These results suggest that DP has anti-apoptotic effects of neutrophils and may regulate protein synthesis and activation of Bad. Moreover, these findings may shed light on elucidation of allergy pathogenesis due to house dust mites.

Identification of a Regulatory Region within the luxR Structural Gene in a Marine Symbiotic Bacterium, Vibrio fischeri

  • Choi, Sang-Ho
    • Journal of Microbiology and Biotechnology
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    • 제4권3호
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    • pp.176-182
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    • 1994
  • The light-organ symbiont of pine cone fish, Vibrio fischeri, senses its presence in the host and responds to environmental changes by differentially expressing its symbiosis-related luminescence genes. The V. fischeri luminescence genes are activated by LuxR protein in the presence of an autoinducer. In an effort to elucidate the mechanism of regulation of luxR, a plasmid containing luxR was mutagenized in vitro with hydroxylamine and a luxR mutant plasmid was isolated by its ability to activate luminescence genes cloned in E. coli in the absence of the autoinducer. The specific base change identified by DNA sequencing was only single base transition at +78 from the transcriptional start of luxR. Based on a Western immunoblot analysis, the nucleotide change directed the synthesis of much higher level of LuxR protein without any amino acid substitutions. The results suggest that the region including the +78th base is presumably internal operator required for autorepression of luxR, and the increased cellular level of LuxR results in activation of luminescence genes by autoinducer independent fashion.

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EFFECT OF MONO-SPECTRAM RADIANT ON AUTONOMIC NERVOUSSYSTEM

  • Shibayama, Y.;Watanuki, S.
    • 한국감성과학회:학술대회논문집
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    • 한국감성과학회 2000년도 춘계 학술대회 및 국제 감성공학 심포지움 논문집 Proceeding of the 2000 Spring Conference of KOSES and International Sensibility Ergonomics Symposium
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    • pp.62-66
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    • 2000
  • This study investigated the effects of certain specific wavelengths of lighting on the autonomic nervous system (ANS) using the heart rate variability (HRV) as an index. Six subjects with normal color vision participated n this study between 15:00 and 17:00 hr to neutralize any visual differences arising from circadian rhythm. The environmental conditions of the laboratory were maintained in complete darkness and the temperature was equilibrated at 24$\Box$ with a relative humidity of 60%. Subjects were only subjected to light stimulation when the pupil of dyes attained a minimum size of 2 mm by projecting illumination equalized with the same spectral radiance of 500-700 nm with 50-nm internal radiance. HRV was calculated from electrocardiogram (ECG) with systematic respiratory control at 0.35 Hz. The results suggest that illumination with certain wavelengths may induce ANS activation.

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Open-Tube에서 Zn확산을 이용한 GaAs에의 $p^+$층 형성 (Formation of $P^+-Layer$ in GaAs Using the Open-Tube Diffusion of Zn)

  • 심규환;강진영;민석기;한철원;최인훈
    • 대한전자공학회논문지
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    • 제25권8호
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    • pp.959-965
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    • 1988
  • Zinc diffusion characteristics and its applicabilities have been studied using an open-tube system. Thermal decomposition of arsenide(As) at gallium arsenide(GaAs) wafer surface was well inhibited by using Ga: poly-GaAs: Zn compositon as a diffusion source. Junction depth was obtained as 4.6x10**7\ulcorner exp)-1.25/kT) where activation energy of diffusion was 1.25eV. From Boltzmann-matano analysis, it could be identified that concentration dependencies of Zn diffusivity well consisted with those of kick-out model. The ideality factor of p+-n junction formed by Zn diffusion was about 1.6 and infrared light intensity was linearly varied in the range of sixty folds. It is concluded frodm these results that Zn diffuses according to kick-out model, and open-tube method is applicable to compound semiconductor devices.

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Thermally activated delayed fluorescence (TADF) from $Sn^{4+}$-porphyrin complexes and their application to organic light emitting diodes - novel pathway for high efficiency electroluminescence

  • Endo, Ayataka;Ogasawara, Mai;Takahashi, Atsushi;Kato, Yoshimine;Adachi, Chihaya
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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    • pp.1411-1413
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    • 2008
  • We developed $Sn^{4+}$-porphyrin complexes that show thermally activated delayed fluorescence (TADF). TADF intensities increased with an increase of temperature because of an acceleration of the reverse intersystem crossing from triplet to singlet excited states by heat activation. TADF component provides a novel pathway for high efficiency OLEDs.

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Effect of Seeding Layers on Preparation of PLZT Thin Films by Sol-Gel Method

  • Hirano, Tomio;Kawai, Hiroki;Suzuki, Hisao;Kaneko, Shoji;Wada, Tatsuya
    • The Korean Journal of Ceramics
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    • 제5권1호
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    • pp.50-54
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    • 1999
  • $(Pb_xLa_{1-x}) (Zr_yTi_{1-y})O_3$ (PLZT) thin films with electrooptic effect are promising for the optical application such as display or light shutter. However, it is difficult to use inexpensive and transparent glass substrates because the conventional process for preparation of PLZT requires temperatures above $600^{\circ}C$. In order to deposit a perovskite PLZT thin films at low processing temperatures through alkoxide route, we have offered several seeding processes which reduce the activation energy for crystallization. In this study, we optimized the stacking structure of multilayered PLZT for obtaining single phase perovskite at lower temperatures. As a result, ferroelectric PLZT thin films with different compositions were successfully prepared at a temperature as low at $500^{\circ}C$.

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Anthocyanins: Targeting of Signaling Networks in Cancer Cells

  • Sehitoglu, Muserref Hilal;Farooqi, Ammad Ahmad;Qureshi, Muhammad Zahid;Butt, Ghazala;Aras, Aliye
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권5호
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    • pp.2379-2381
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    • 2014
  • It is becoming progressively more understandable that phytochemicals derived from edible plants have shown potential in modelling their interactions with their target proteins. Rapidly accumulating in-vitro and in- vivo evidence indicates that anthocyanins have anticancer activity in rodent models of cancer. More intriguingly, evaluation of bilberry anthocyanins as chemopreventive agents in twenty-five colorectal cancer patients has opened new window of opportunity in translating the findings from laboratory to clinic. Confluence of information suggests that anthocyanins treated cancer cells reveal up-regulation of tumor suppressor genes. There is a successive increase in the research-work in nutrigenomics and evidence has started to shed light on intracellular-signaling cascades as common molecular targets for anthocyanins. In this review we bring to l imelight how anthocyanins induced apoptosis in cancer cells via activation of extrinsic and intrinsic pathways.

Ionizing Radiations Induce Apoptosis in TRAIL Resistant Cancer Cells: in vivo and in vitro Analysis

  • Silva, Marcela Fernandes;Khokhar, Abdur Rehman;Qureshi, Muhammad Zahid;Farooqi, Ammad Ahmad
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권5호
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    • pp.1905-1907
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    • 2014
  • Increasingly it is being realized that despite considerable advancements in therapeutic interventions related to treatment of cancer, satisfactory results are still difficult to achieve. Rapidly accumulating evidence has started to shed light on the fact that cancer cells escape from death via constitutive activation of pro-survival signaling cascades. Cell biology and genetics have extensively enhanced our current understanding of the molecular mechanisms that underlie loss of apoptosis in cancer cells. This review is focused on ionizing radiation mediated restoration of TRAIL mediated apoptosis as evidenced by cell culture and animal model studies. Moreover, we also bring to the limelight radiation induced expression of miRNAs and how miRNAs further control response of cancer cells to radiation.

SYNTHESIS AND APPLICATION OF NEW SPIN PROBES

  • Kim, S.D.;Freeman, H.S.;Mcgregor, R.
    • 한국섬유공학회:학술대회논문집
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    • 한국섬유공학회 1990년도 제2차 학술발표초록집
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    • pp.67-67
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    • 1990
  • Three non-ionic and two anioinic spin probes, differing in size and substituent, were synthesized. Their mobility in dried nylon 6 film was investicated by the spin probe technique using electron spin resonance spectrometer. When the size of a spin probe was large and the interaction between the probe molecules and polymer chains existed, the mobility of spin probes decreased. From Arrhenius plots of rotational correlation time, one discontinuity point ($T_d$) was determined. The activation energies for rotation below and above $T_d$ were discussed in terms of the mode of probe rotation. Three spin probes could be viewed as azo dyes having a built-in nitroxide radical. Photolysis of them in dimethylformamide and in nylon 6 film was performed by exposure to 254 nm UV light in the presence of air. It was found that dyes having a built-in nitroxide radical showed better photostability than dyes derived from ${\bata}-naphthol$..

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Debye 이론을 이용한 유기 EL용 Alq3계 재료의 Trap Level 측정 (Trap Level Study of Alq3 for OLED with Debye Dielectric Relaxation)

  • 정용석;정연태;김종태
    • 한국전기전자재료학회논문지
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    • 제17권6호
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    • pp.668-672
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    • 2004
  • Upon Debye's dielectric relaxation theory, we tried simple determination method of trap level in organic EL materials. From dielectric measurements in the 20 Hz - 1 MHz frequency range and in the 150 K - 320K temperature range, the depth of traps in Alq$_3$ filled with remaining electrons was determinated. Comparing to other determination techniques like TSL, or TL, the apparatus all we need is just simple LCR meter, thermometer and cooling method(liquid nitrogen). The mean activation energy is about 0.20 eV. It is in good agreement with previous determinations by other techniques like TSL. This results consolidate the validity of Burrow's transport mechanism model. Further intensified experiment with UV light on the dielectric absorption(Photodipolair effect) was nevertheless disturbed by the photoconductivity component.