• Title/Summary/Keyword: Light dependent

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p38 mitogen-activated protein kinase-dependent activation of contractility in rat thoracic aorta

  • Yeol, An-Hui
    • Proceedings of the Korean Biophysical Society Conference
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    • 2001.06a
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    • pp.24-24
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    • 2001
  • The present study was undertaken to determine whether p38 mitogen-activated protein kinase participates in the regulation of vascular smooth muscle contraction by endothelin-I (ET-1) in rat thoracic aorta. ET-1 induced a sustained contraction. In contrast, both the intracellular Ca$\^$2+/ and myosin light chain (MLC) phosphorylations were not sustained.(omitted)

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Fabrications and Characterizations of InGaN/GaN Quantum Well Light Emitting Devices Including Photonic Crystal Nanocavity Structures (광결정 Nanocavity를 갖는 InGaN/GaN 양자우물구조의 청색 광소자 공정 및 특성평가)

  • Choi, Jae-Ho;Lee, Jung-Tack;Kim, Keun-Joo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.22 no.12
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    • pp.1045-1057
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    • 2009
  • The authors investigated the InGaN/GaN multi-quantum well blue light emitting devices with the implementation of the photonic crystals fabricated at the top surface of p-GaN layer and the bottom interface of n-GaN layer. The top photonic crystals result in the lattice-dependent photoluminescence spectra at the wavelength of 450 nm and however, the bottom photonic crystal shows a big shift of the photoluminescence peak from 444 nm to 394 nm. The sample with the bottom photonic crystal structure also shows the lasing effect at the wavelength of 468 nm. Furthermore, the quality enhancement for the crystal growth of GaN thin film on the bottom photonic crystal comes from the modulated compressive stress which was measured by the micro-Raman spectroscopy.

Fire Resistance Performance of High Strength-Light Weight Concrete (고강도를 적용한 1종 경량골재 콘크리트의 내화특성)

  • Song, Hun;Lee, Jong-Chan;Lee, Sea-Hyun
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.11a
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    • pp.749-752
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    • 2005
  • Normally, the degradation of concrete member exposed to fire is largely dependent on the fire scale and fire condition. With all ensuring the fire resistance structure as a method of setting the required cover thickness to fire, the RC is significantly affected from the standpoint of its structural stability that the compressive strength and elastic modulus is reduced by fire. Thus, this study is concerned with experimentally investigating fire resistance of high strength-light weight concrete. From the test result, high strength-light weight concrete is happened explosive spalling. The decrease of cross section caused by explosive spalling made sharp increasing gradient of inner temperature.

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Electrical and Optical Properties of Organic Light Emitting Devices Using Blue Fluorescent and Orange Phosphorescent Materials (청색형광재료와 황색인광 재료를 이용한 OLEDs의 전기 및 광학적 특성)

  • Seo, Yu-Seok;Moon, Dae-Gyu
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2010.06a
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    • pp.155-155
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    • 2010
  • We have investigated organic light-emitting devices by doping phosphorescent orange and fluorescent blue emitters into the separate layers of single host. The electroluminescence spectra and current efficiency were strongly dependent on the location of each doped layers. The luminance-voltage (L-V) characteristics of the device2 (ITO/Hole Transport Layer/Orange Phosphorescent emissive layer/Blue Fluorescent emissive layer/Electron Transport Layer/liF/Al) showed the maximum current efficiency of 19.5 cd/A.

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Behavior Therapy and Light Therapy of Insomnia (불면증의 행동치료 및 광치료)

  • Seo, Wan-Seok
    • Sleep Medicine and Psychophysiology
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    • v.10 no.1
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    • pp.20-25
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    • 2003
  • Many people suffer from chronic insomnia. Inappropriate sleep causes attention difficulties, decreased work efficiency, and increased traffic accidents and disasters. Evaluating the precise causes of insomnia prior to treatment is very important, because chronic insomnia can be a secondary symptom of other medical, psychiatric, and sleep disorders. Medication and behavior therapy are not exclusive of each other, and both treatments are beneficial to some patients, but currently many physicians and patients tend to be dependent only on medication. While long-term medication causes various degrees of dependency, tolerance, and withdrawal symptoms, behavior therapy has a stable effect over a long period. Behavior therapy is one of the most important treatment modalities for chronic insomnia. It shortens sleep latency, and decreases frequency of awakening during sleep. The rationale and practice of currently used behavior therapy and light therapy will be reviewed in this study.

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Built-in Voltage in Organic Light-emitting Diodes depending on the Alg3 Layer Thickness (Alg3 두께 변화에 따른 유기 발광 소자의 내장 전압)

  • Lee, Eun-Hye;Yoon, Hee-Myoung;Kim, Tae-Wan
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.21 no.3
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    • pp.255-259
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    • 2008
  • Built-in voltage in ITO/$Alq_3$/ Al organic light-emitting diodes was studied by varying a thickness of $Alq_3$ layer using modulated photocurrent technique at ambient condition. A thickness of the $Alq_3$ layer was varied from 100 to 250 nm. From the bias voltage-dependent photocurrent, built-in voltage of the device was able to be determined. The obtained built-in voltage is about 0.8 V irrespective of the $Alq_3$ layer thickness in the device. This value of built-in voltage confirms that the built-in voltage is generated due to a difference of work function of the anode and cathode. The $Alq_3$ layer thickness independent built-in voltage indicates that the built-in electric field in the device is uniform across the organic layer.

Stimulation of Tissue Transglutaminase Activity by Clostridium botulinum Neurotoxin Type B

  • Moon, Yu-Seok;Gi-Hyeok;Rhee, Sang-Dal;Jung, Hyun-Ho
    • Journal of Microbiology
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    • v.41 no.2
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    • pp.161-164
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    • 2003
  • Recombinant light chain of Clostridium botulinum neurotoxin type B stimulated transglutaminase activity in a dose dependent manner, Compared to native toxin, recombinant light chain showed av greater stimulatory effect on transglutaminase activity. Zn-chelating agents, inhibiting the proteolytic activity of the clostridial toxins, did not interfere with this stimulation. These results suggest that the light chain plays a major stimulatory role, which is not due to its metallopeptidase activity, but is possibly due to specific interaction with transglutaminase. More importantly, this report provides a new insight into the intracellular action of C. botulinum neurotoxins.

Current-Voltage Characteristics of Organic Light-Emitting Diodes with a Variation of Temperature (온도 변화에 따른 유기 전기 발광 소자의 전압-전류 특성)

  • Kim, Sang-Geol;Hong, Jin-Ung;Kim, Tae-Wan
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.51 no.7
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    • pp.322-327
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    • 2002
  • Temperature-dependent current-voltage characteristics of organic light-emitting diodes(OLEDs) were studied in a device structure of ITO/TPD/Alq$_3$/Al to understand conduction mechanism. The current-voltage characteristics were measured in the temperature range of 8K ~ 300K. We analyzed an electrical conduction mechanism of the OLEDS using space-charge-limited current(SCLC) and Fowler-Nordheim tunneling. In the temperature range above 150k, the conduction mechanism could be explained by space charge limited current from the inversely proportional temperature dependence of exponent m. The characteristic trap energy is found to be about 0.15ev. At low temperatures below 150k, the Fowler-Nordheim tunneling conduction mechanism is dominant. We have obtained a zero field barrier height to be about 0.6~0.8eV.

Characteristics of Preflashover Light Emission in High Field $SiO_2$-vacuum Systems (고전계 $SiO_2$진공계에서 전구섬락 광방출 특성)

  • Kim, J.D.;Jung, J.G.;Joo, S.C.;Jang, G.H.;Lee, S.H.;Lee, Y.K.;Kim, D.H.
    • Proceedings of the KIEE Conference
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    • 1997.07e
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    • pp.1794-1797
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    • 1997
  • The preflashover light emission of the $SiO_2$-dielectric system behavior under high electric field is discussed. Time dependence of the voltage drop, electrical current, and light emission, are analyzed for high-purity $SiO_2$-vacuum systems under impulse voltage stress. We will summarize the experimental results showing the main feature of the time-dependent system response up to breakdown.

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