• Title/Summary/Keyword: Blue LED

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Dynamics of RNA Bacteriophage MS2 Observed with a Long-Lifetime Metal-Ligand Complex

  • Kang, Jung Sook;Yoon, Ji Hye
    • Journal of Photoscience
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    • v.11 no.1
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    • pp.35-40
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    • 2004
  • [Ru(2,2'-bipyridine)$_2$(4,4'-dicarboxy-2,2'-bipyridine)]$^{2+}$(RuBDc) is a very photostable probe that possesses favorable photophysical properties including long lifetime, high quantum yield, large Stokes' shift, and highly polarized emission. To evaluate the usefulness of this luminophore (RuBDc) for studying macromolecular dynamics, its intensity and anisotropy decays when conjugated to RNA bacteriophage MS2 were examined using frequency-domain fluorometry with a high-intensity, blue light-emitting diode (LED) as the modulated light source. The intensity decays were best fit by a sum of two exponentials, and the mean intensity decay time was 442.2 ns. The anisotropy decay data showed a single rotational correlation time (2334.9 ns), which is typical for a spherical molecule. The use of RuBDc enabled us to measure the rotational correlation time up to several microseconds. These results indicate that RuBDc can be useful for studying rotational diffusion of biological macromolecules.s.

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Isolation and Structure Determination of a Proteasome Inhibitory Metabolite from a Culture of Scytonema hofmanni

  • Shim, Sang-Hee;Chlipala, George;Orjala, Jimmy
    • Journal of Microbiology and Biotechnology
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    • v.18 no.10
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    • pp.1655-1658
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    • 2008
  • Cyanobacteria, blue-green algae, are a rich source of bioactive secondary metabolites with many potential applications. The ubiquitin-proteasome proteolytic system plays an important role in selective protein degradation and regulates cellular events including apoptosis. Cancer cells are more sensitive to the proapoptotic effects of proteasome inhibition than normal cells. Thus, proteasome inhibitors can be potential anticancer agents. Cyanobacteria have been shown to be a rich source of highly effective inhibitors of proteases. A proteasome inhibitor was screened from an extract of the culture of Scytonema hofmanni on the basis of its inhibitory activity, which led to the isolation of nostodione A with an $IC_{50}$ value of 50${\mu}M$. Its structure was determined by spectroscopic methods such as $^{1}H$-NMR and ESI-MS spectral analyses.

Antioxidative Constituents from the Twigs of Vitex rotundifolia

  • Kim, Dae-Keun
    • Biomolecules & Therapeutics
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    • v.17 no.4
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    • pp.412-417
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    • 2009
  • In the course of screening for antioxidant compounds by measuring the radical scavenging effect on DPPH (1,1-diphenyl- 2-picrylhydrazyl), a total extract of the twigs of Vitex rotundifolia (Verbenaceae) was found to show potent antioxidant activity. Subsequent activity-guided fractionation of the methanolic extract led to the isolation of three iridoid compounds, 10-O-vanilloylaucubin (1), 10-O-p-hydroxybenzoylaucubin (2) and aucubin (3), two C-glycoside flavones, vitexin (4) and orientin (5), and a quinic acid derivative, 3,4-di-O-caffeoylquinic acid (6). Their structures were elucidated by spectroscopic studies. Among them, compounds 5 and 6 showed the significant antioxidative effects on DPPH free radical scavenging test. In riboflavin-NBT-light and xanthine-NBT-xanthine oxidase systems, compounds 5 and 6 exhibited the formation of the blue formazan in a dose-dependent manner. Compounds 5 and 6 showed better superoxide quenching activities than vitamin C.

Combinatorial Synthesis and Screening of the $Eu^{2+}$-activated Phosphors for LED in the System CaO-$Al_2O_3-SiO_2$

  • Park, Seung-Hyok;Yoon, Ho-Shin;Kim, Chang-Hae;Jang, Ho-Gyeom
    • 한국정보디스플레이학회:학술대회논문집
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    • 2004.08a
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    • pp.647-649
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    • 2004
  • We have synthesized phosphor in the system CaO-$Al_2O_3-SiO_2$ by combinatorial polymerized-complex method. The application of combinatorial synthesis and characterization of luminescent materials has been enlarged to identification and optimization in interesting new phosphor. In this study, we investigated luminescent properties of above-mentioned materials by excitation and emission spectra. In $Eu^{2+}$ activated $Ca_1Al_2Si_2O_8$ phosphor emit the blue light.

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The Trend of Clothing Colors Fitted for Personal Color Types (개인색채 유형에 따라 어울리는 의복색 경향)

  • 박화순
    • Journal of the Korean Society of Costume
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    • v.52 no.6
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    • pp.15-24
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    • 2002
  • This paper is to investigate and analyze the clothing colors fitted for personal color types and to help consumers express individual characteristics by clothing colors suitable for themselves. The comparison of sixty three clothing colors with three personal color types. and investigation and analysis of the best clothing colors of each type have led to the following results. Those belong to warm Personal Color Type don't have a variety of choices for clothing colors. so they should be careful of choosing clothing colors. They will do well to choose dark tone colors for their clothing. Those of Cold Personal color Type have a wide range of choices for clothing colors. They have an advantage of expressing themselves in various ways. Neutrals, Blue and Yellow have been found to go well with them. Those of Mixed Personal Type are advised to wear bright and pale tone colors such as Purple, Green, and Red. It will be desirable that the choice of clothing colors should conform to each personal color for the tones of clothing colors should conform to each personal color for the tones of clothing colors make difference according to personal color types.

Electrical Characteristics of Flat Cesium Antimonide Photocathode Emitters in Panel Devices

  • Jeong, Hyo-Soo
    • Transactions on Electrical and Electronic Materials
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    • v.17 no.5
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    • pp.306-309
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    • 2016
  • The Cs3Sb photocathode was formed by non-vacuum process technology. An in-situ vacuum device was fabricated successively with flat cesium antimonide photocathode emitters fabricated in a process chamber. The electrical properties of the device were characterized. Electron emission from the devices was induced by photoemitted electrons, which were accelerated by an anode electric field that was shielded from the photoemitter surface. The electrical characteristics of the devices were investigated by measuring the anode current as a function of device operation times with respect to applied anode voltages. Planar blue LED light with a 450 nm wavelength was used as an excitation source. The results showed that the cesium antimonide photocathode emitter has the potential of long lifetime with stable electron emission characteristics in panel devices. These features demonstrate that the cesium antimony photocathodes produced by non-vacuum processing technology is suitable for flat cathodes in panel device applications.

Optimal Driving of Photo-Sensor for Control of A Mixed Environment (복합환경제어를 위한 광량 센서장치의 최적구동)

  • Kim, Jong-Man;Kim, Won-Sop;Kim, Hyung-Suk
    • Proceedings of the KIEE Conference
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    • 2011.07a
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    • pp.2110-2111
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    • 2011
  • Optimal Driving of Photo-Sensor for Control of a Mixed Environment was realized. The control system was carried out to investigate into the characteristics of Real time control of temperature and humidity at sprouts cutivators. Especially, for led's control for the cultivation of sprouts we have composed a Combined Automatic Control System possible for the control of temperature and humidity at the same time. The applied Photo-Sensor measurement are blue, green, red, white, yellow leds. And we had also designed the Web Programming for the automatic control about sprouts plants.

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Change in Chromatic Characteristics with the Oil Degradation (오일 열화 진행에 따른 오일의 색채 특성 변화)

  • Kong, H.;Ossia, C.V.;Han, H.G.;Markova, L.
    • Tribology and Lubricants
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    • v.24 no.1
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    • pp.7-13
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    • 2008
  • In this work, a simple and low cost sensor technique is proposed to test oil color in real time using in-line sensor. It is presented to use a ratio of intensity in red wavelength range to intensities of green and blue wavelength ranges (defined as a 'chromatic ratio') in order to estimate the oil color change. The proposed sensor technique is realized by irradiating a white LED as light source and a RGB color sensor as photoreceiver, and the chromatic ratio of various types of used oils are measured. The results show that chromatic ratio generally reflects chemical deterioration of oil, including oil oxidation and thermal degradation. It is concluded that the proposed sensor could be used for an effective oil monitoring technology.

Purification and characterization of alcohol dehydrogenase encoded by Zymomonas mobilis gene in Escherichia coli

  • 신병식;윤기홍;박무영
    • Proceedings of the Korean Society for Applied Microbiology Conference
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    • 1986.12a
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    • pp.521.3-522
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    • 1986
  • A gene encoding alcohol dehydrogenase (ADH) in Zymomonas mobilis was cloned into E. coli JM 83 with plasmid pUC 9. The ADH produced by the E. coli transformant was purified bysonication, (NH$^4$)2SO4 fractionation, Affi-Gel blue and hydroxylapatite chromatography. The ADH produced by Z. mobilis was also purified by the same procedures. The two enzyme preparations were characterized and compared. It was found that the E. coli ADH was identical to one of two ADH isozymes of Z. mobilis. Analytical gel filtrations led to the conclusion that the molecule of E. coli ADH was composedv of four subunits having molecular weight of 40,000 (+1,000) dalton each The effect of metal ions on ADH activity and optimum pH were investigated.

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Multi Cultivation Remote-Control System(MCRS) for Crops Through Characteristics of Multi-Safe Sensors (다중 안전센서 특성을 이용한 다중재배 원격제어장치)

  • Kim, Jong-Man;Cho, Ja-Yong;Seo, Beom-Seok
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.58 no.4
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    • pp.619-622
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    • 2009
  • Multi Cultivation Remote-control System(MCRS) for crpos through characteristics of multi-safe sensors was realized. It was carried out to investigate into the effect of LED Control with the physiological activity of crops(for examples, sprouts). We have also composed a Combined Automatic Control System possible for the control of temperature and humidity at the same time. The applied multi-safe sensors for measurement are blue, green, red, white, yellow leds and humidity sensors, web camera sensors under safe conditions for crops cultivation. And we producted the remote control OS using Linux and defined the characteristics of automatic control about sprouts.