• Title/Summary/Keyword: Blue LED

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Dynamics of Supercoiled and Relaxed pTZ18U Plasmids Probed with a Long-Lifetime Metal-Ligand Complex

  • Kang, Jung-Sook;Abugo, Omoefe O.;Lakowicz, Joseph R.
    • BMB Reports
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    • v.35 no.4
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    • pp.389-394
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    • 2002
  • $[Ru(bpy)_2(dppz)]^2+$ (bpy=2,2'-bipyfidine, dppz=dipyrido[3,2-a:2',3'-c]phenazine) (RuBD), a long-lifetime metal-ligand complex, displays favorable photophysical properties. These include long lifetime, polarized emission, but no significant fluorescence from the complex that is not bound to DNA. To show the usefulness of this luminophore (RuBD) for probing the bending and torsional dynamics of nucleic acids, its intensity and anisotropy decays when intercalated into supercoiled and relaxed pTZ18U plasmids were examined using frequency-domain fluorometry with a blue light-emitting diode (LED) as the modulated light source. The mean lifetimes for the supercoiled plasmids (< $\tau$ >=148 ns) were somewhat shorter than those for the relaxed plasmids (< $\tau$ >=160 ns). This suggests that the relaxed plasmids were shielded more efficiently from water. The anisotropy decay data also showed somewhat shorter slow rotational correlation times for supercoiled plasmids (288 ns) than for the relaxed plasmids (355 ns). The presence of two rotational correlation times suggests that RuBD reveals both the bending and torsional motions of the plasmids. These results indicate that RuBD can be useful for studying both the bending and torsional dynamics of mucleic acids.

A Study on the Changes of Social Meaning of Androgynous Image in Fashion Magazine(II) -Focused Fashion Design Element- (패션잡지에 나타난 양성이미지의 사회적 의미변화에 관한 연구(II) -디자인 요소를 중심으로-)

  • 유홍식;황선진
    • Journal of the Korean Society of Costume
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    • v.53 no.5
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    • pp.111-124
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    • 2003
  • The purpose of this study is to analyze how the women´s fashion with the design elements(silhouette, material, color, detail and trimming) of androgynous image which has appeared on our specialized fashion magazine from 1986 through 2000. As a result of this study I drew the following conclusion. 1. The bon silhouette led the market in the first stage of mid 1980. The wool and leather with the masculine image, cotton and soft material with unisex image were used to express the androgynous image. The dark and mono tone with the masculine image were used a lot in color. In women´s fashion the minimalism style with simple image was expressed escaping from the decoration, in which the detail and trimming was not found as in men´s wear. 2. It showed that more and more feminine image was accepted in the second stage of early 1990. Women´s wear silhouette with the androgynous image has changed from masculine box silhouette boomed in the first stage to hourglass silhouette and slim silhouette. The wool and leather were used a lot as the materials in the first stage but the usage of the cotton with unisex image and soft texture were getting increased. The main colors were the black and the blue but the usage of the white and the red were on the increase showing the range of the use was extending. In the meantime, the detail and trimming were hardly used like in the first stage. 3. In the third stage of the late 1990, the silhouette has changed to slim style. The wool and leather were mainly used as the materials but the cotton and silk were on the increase showing that the materials of the feminine image were used in the women´s fashion with the androgynous image as well as the materials of masculine image. In color, the black and the white of the masculine image were used increasingly by the effect of the minimalism and the usage of the colors were various for the rising frequency of the trend colors usage.

Changes of Cortical Activation Pattern Induced by Motor Learning with Serial Reaction Time Task (시열반응과제의 운동학습이 대뇌피질 활성화의 변화에 미치는 영향)

  • Kwon, Yong-Hyun;Chang, Jong-Sung;Kim, Chung-Sun
    • The Journal of Korean Physical Therapy
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    • v.21 no.1
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    • pp.65-71
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    • 2009
  • Purpose: Numerous investigators demonstrated that adaptative changes were induced by motor skill acquisition in the central nervous system. We investigated the changes of neuroelectric potential following motor learning with serial reaction time task in young healthy subjects, using electroencephalography (EEG). Methods: Twelve right-handed normal volunteers were recruited, who have no history of neurological dysfunction and were given to written the informed consent. All subjects were assigned to flex to extend the wrist joint or flex the thumb for pressing the matched button as quickly and accurately as possible, when one of five colored lights was displayed on computer screen (red, yellow, green, blue, white). EEG was measured, whenfive types simulations ware presented randomly with equal probabilities of 20% in total 200 times at the pre and post test. And they were scheduled for 30 minutes practice session during two consecutive days in the laboratory. Results: The results showed that the reaction time at the post test was significantly reduced, compared to one of the pre test in serial reaction time task. In EEG map analysis, the broaden bilateral activation tended to be changed to the focused contralateral activation in the frontoparietal area. Conclusion: These findings showed that acquisition of motor skill led to product more fast motor execution, and that motor learning could change cortical activation pattern, from the broaden bilateral activation to the focused contralateral activation. Thus we concluded that the adaptative change was induced by motor learning in healthy subjects.

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Chemopreventive Actions of Blond and Red-Fleshed Sweet Orange Juice on the Loucy Leukemia Cell Line

  • Dourado, Grace KZS;Stanilka, Joy M;Percival, Susan S;Cesar, Thais B
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.15
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    • pp.6491-6499
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    • 2015
  • Background: Red-fleshed sweet orange juice (ROJ) comes from a new variety of citrus cultivated in Brazil that contains high levels of ${\beta}$-carotene and lycopene, and similar amounts of hesperidin (HSP) and nutrients, equivalently to blond orange juice (BOJ). Such bioactive compounds are associated with chemopreventive actions in several cancer cell lines. The purpose of this study was to examine the cytotoxicity, cell cycle, apoptosis, and cytokine secretion after BOJ, ROJ, and HSP treatment of a novel T acute lymphoblastic leukemia cell line, Loucy. Materials and Methods: Loucy cells were incubated for 24-h with BOJ, ROJ, and HSP, and the viability was measured using trypan blue. Cell cycling and apoptosis were assessed by propidium iodide (PI) and annexin V-FITC/PI flow cytometry, respectively. Secretion of cytokines $IL-1{\alpha}$, $IL1-{\beta}$, IL-2, IL-4, IL-6, IL-10, IL-17A, $IFN{\gamma}$, $TNF{\alpha}$, $TGF{\beta}$, $MIP{\alpha}$, and $MIP{\beta}$ was determined by ELISA array. Results: BOJ and ROJ treatments promoted Loucy cell cytotoxicity. Additionally, BOJ induced cell cycle arrest in the G0/G1 phase, and decreased the cell accumulation in the G2/M. ROJ decreased only the G0/G1 fraction, while HSP did not change the cell cycle. BOJ led to apoptosis in a different fashion of ROJ, while the first treatment induced apoptosis by increase of late apoptosis and primary necrotic fractions, the second increased early and late apoptosis, and primary necrotic fraction compared to positive controls. HSP had no effect on apoptosis. IL-6 and IL-10 were abrogated by all treatments. Conclusions: Taking together, these results suggest potential chemopreventive effects of BOJ and ROJ on Loucy cells.

Photoluminescence and Fabrication of Zirconia Nanofibers from Electrospinning an Alkoxide Sol Templated on a Polyvinyl Butyral (폴리비닐 부티랄에 붙힌 지르코늄 알콕시드 졸을 사용한 전기방사에서 지르코니아 나노섬유 제조와 광발광)

  • Ko, Tae-Gyung;Han, Kyu-Suk;Rim, Tae-Kyun;Oh, Seoung-Gyu;Han, Sang-Whan
    • Journal of the Korean Ceramic Society
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    • v.47 no.4
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    • pp.343-352
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    • 2010
  • A zirconia gel/polymer hybrid nanofiber was produced in a nonwoven fabric mode by electrospinning a sol derived from hydrolysis of zirconium butoxide with a polyvinyl butyral. Results indicated that the hydroxyl groups on the vinyl alcohol units in the backbone of the polymer were involved in the hydrolysis as well as grafting the hydrolyzed zirconium butoxide. In addition, use of acetic acid as a catalyst resulted in further hydrolysis and condensation in the sol, which led to the growth of -Zr-O-Zr- networks among the polymer chains. These networks gradually transformed into a crystalline zirconia structure upon heating. The as-spun fiber was smooth but partially wrinkled on the surface. The average fiber diameter was $690{\pm}110\;nm$. The fiber exhibited a strong but broad blue photoluminescence with its maximum intensity at a wavelength of ~410 nm at room temperature. When the fiber was heat-treated at $400^{\circ}C$, the fiber diameter shrunk to $250{\pm}60\;nm$. Nanocrystals which belonged to a tetragonal zirconia phase and were ~5 nm in size appeared. A strong white photoluminescence was observed in this fiber. This suggests that oxygen or carbon defects associated with the formation of the nanocrystals play a role in generating the photoluminescence. Further heating to $800^{\circ}C$ resulted in a monoclinic phase beginning to form In the heat-treated fibers, coloring occurred but varied depending on the heating temperature. Crystallization, coloring, and phase transition to the monoclinic structure influenced the photoluminescence. At $600^{\circ}C$, the fiber appeared to be fully crystallized to a tetragonal zirconia phase.

Short Low Concentration Cisplatin Treatment Leads to an Epithelial Mesenchymal Transition-like Response in DU145 Prostate Cancer Cells

  • Liu, Yi-Qing;Zhang, Guo-An;Zhang, Bing-Chang;Wang, Yong;Liu, Zheng;Jiao, Yu-Lian;Liu, Ning;Zhao, Yue-Ran
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.3
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    • pp.1025-1028
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    • 2015
  • Background: Prostate cancer is one of the main causes of cancer death, and drug resistance is the leading reason for therapy failure. However, how this occurs is largely unknown. We therrfore aimed to study the response of DU145 cells to cisplatin. Materials and Methods: Du145 prostate cancer cells were treated with a low dose of cisplatin for 24 h and cell viability and number were determined by MTT assay and trypan blue exclusion assay, respectively. The real time polymerase chain reaction (PCR) was used to assess responses to cisplatin treatment. Results: After 24h $2{\mu}g/ml$ treatment did not result in significant reduction in cell viability or number. However, it led to enhanced cancer cell invasiveness. E-cadherin mRNA was reduced, and vimentin, Snail, Slug, metalloproteinase 9 (MMP9) mRNA expression increased significantly, a feature of epithelial-mesenchymal transition (EMT). Conclusions: Short time low concentration cisplatin treatment leads to elevated invasiveness of DU145 cancer cells and this is possibly due to EMT.

Improving the Productivity of Recombinant Protein in Escherichia coli Under Thermal Stress by Coexpressing GroELS Chaperone System

  • Kim, So-Yeon;Ayyadurai, Niraikulam;Heo, Mi-Ae;Park, Sung-Hoon;Jeong, Yong-Joo;Lee, Sun-Gu
    • Journal of Microbiology and Biotechnology
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    • v.19 no.1
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    • pp.72-77
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    • 2009
  • Here, we demonstrate that the overexpression of the GroELS chaperone system, which assists the folding of intracellular proteins and prevents aggregation of its biological targets, can enhance the thermotolerance of Escherichia coli strains and facilitate the production of recombinant protein under thermal stress. The overexpression of GroELS led to an about 2-fold higher growth rate of E. coli XL-1 blue than control at $45^{\circ}C$ and induced the growth of the strain even at $50^{\circ}C$, although the growth was not sustained in the second-round culture. The effect of GroELS overexpression was also effective on other E. coli strains such as JM109, $DH5{\alpha}$, and BL21. Finally, we have shown that coexpression of GroELS allows us to produce recombinant protein even at $50^{\circ}C$, a temperature at which the protein production based on E. coli is not efficient. This study indicates that the employment of the GroELS overexpression system can expand the range of environmental conditions for E. coli.

Emission and Structural Properties of Titanium Oxide Nanoparticles-coated a-plane (11-20) GaN by Spin Coating Method

  • Kim, Ji-Hoon;Son, Ji-Su;Baik, Kwang-Hyeon;Park, Jung-Ho;Hwang, Sung-Min
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.02a
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    • pp.146-146
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    • 2011
  • The blue light emitting diode (LED) structure based on non-polar a-plane (11-20) GaN which was coated TiO2 nanoparticles using spin coating method was grown on r-plane (1-102) sapphire substrates to improve light extraction efficiency. We report on the emission and structural properties with temperature dependence of photoluminescence (PL) and x-ray rocking curves (XRC). From PL results at 13 K of undoped GaN samples, basal plane stacking fault (BSF) and near band edge (NBE) emission peak were observed at 3.434 eV and 3.484 eV, respectively. We also found the temperature-induced band-gap shrinkage, which was fitted well with empirical Varshini's equation. The PL intensity of TiO2 nanoparticles ?coated multiple quantum well (MQW) sample is decayed slower than that of no coating sample with increasing temperature. The anisotrophic strain and azimuth angle dependence in the films were shown from XRC results. The full width at half maximum (FWHM) along the GaN [11-20] and [1-100] directions were 564.9 arcsec and 490.8 arcsec, respectively. A small deviation of FWHM values at in-plane direction is attributed to uniform in-plane strain.

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Al-doping Effects on Structural and Optical Properties of Prism-like ZnO Nanorods

  • Kim, So-A-Ram;Kim, Min-Su;Cho, Min-Young;Nam, Gi-Woong;Lee, Dong-Yul;Kim, Jin-Soo;Kim, Jong-Su;Son, Jeong-Sik;Leem, Jae-Young
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.420-420
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    • 2012
  • ZnO seed layer were deposited on quartz substrate by sol-gel method and prism-like Al-doped ZnO nanorods (AZO nanorods) were grown on ZnO seed layer by hydrothermal method with various Al concentration ranging from 0 to 2.0 at.%. Structural and optical properties of the AZO nanorods were investigated by field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), photoluminescence (PL). The diameter of the AZO nanorods was smaller than undoped ZnO nanorods and its diameter of the AZO nanorods decreased with increasing Al concentration. In XRD spectrum, it was observed that stress and full width at half maximum (FWHM) of the AZO nanorods decreased and the 'c' lattice constant increased as the Al concentration increased. From undoped ZnO nanorods, it was observed that the green-red emission peak of deep-level emission (DLE) in PL spectra. However, after Al doping, not only a broad green emission peak but also a blue emission peak of DLE were observed.

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Optical and microstructural behaviors in the GaN-based LEDs structures with the p-GaN layers grown at different growth temperatures (GaN 기반 LED구조의 p-GaN층 성장온도에 따른 광학적, 결정학적 특성 평가)

  • Kong, Bo-Hyun;Kim, Dong-Chan;Kim, Young-Yi;Han, Won-Suk;Ahn, Cheol-Hyoun;Choi, Mi-Kyung;Cho, Hyung-Koun;Lee, Ju-Young;Kim, Hong-Seung
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.06a
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    • pp.144-144
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    • 2008
  • Blue light emitting diode structures consisting of the InGaN/GaN multiple quantum wells were grown by metalorganic chemical vapor deposition at different growth temperatures for the p-GaN contact layers and the influence of growth temperature on the emission and microstructural properties was investigated. The I-V and electroluminescence measurements showed that the sample with a p-GaN layer grown at $1084^{\circ}C$ had a lower electrical turn-on voltage and series resistance, andenhanced output power despite the low photoluminescence intensity. Transmission electron microscopy (TEM) revealed that the intense electro luminescence was due to the formation of a p-GaN layer with an even distribution of Mg dopants, which was confirmed by TEM image contrast and strain evaluations. These results suggest that the growth temperature should be optimized carefully to ensurethe homogeneous distribution of Mg as well as the total Mg contents in the growth of the p-type layer.

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