Crystalline structure dependence of luminescent properties of Eu³⁺-activated Y₂O₃-Al₂O₃ system phosphors

Jung, H.C.,Park, J.Y.,Seeta Rama Raju, G.,Jeong, J.H.,Moon, B.K.,Kim, J.H.,Choi, H.Y. Elsevier 2009 Current Applied Physics Vol.9 No.3

Eu<SUP>3+</SUP> doped Y<SUB>3</SUB>Al<SUB>5</SUB>O<SUB>12</SUB> (YAG), YAlO<SUB>3</SUB> (YAP) and Y<SUB>4</SUB>Al<SUB>2</SUB>O<SUB>9</SUB> (YAM) nanophosphors were prepared by solvothermal reaction method. The structural properties were studied by using their XRD measurements and the luminescent properties of these phosphors were investigated by the measurement of their excitation and emission spectra along with their decay curves. The relationship between the structures and the photoluminescence properties of the phosphors has been studied. The emission spectrum of Eu<SUP>3+</SUP> doped YAG phosphor is dominated by orange emission due to <SUP>5</SUP>D<SUB>0</SUB>-><SUP>7</SUP>F<SUB>1</SUB> transition with inversion symmetry. However, the emission spectrum of Eu<SUP>3+</SUP> doped YAP phosphor is dominated by red emission due to <SUP>5</SUP>D<SUB>0</SUB>-><SUP>7</SUP>F<SUB>2</SUB> transition without inversion symmetry. The PL spectrum of Eu<SUP>3+</SUP> doped YAM phosphor consists of similar emission intensities for both <SUP>5</SUP>D<SUB>0</SUB>-><SUP>7</SUP>F<SUB>1</SUB> (590nm) and <SUP>5</SUP>D<SUB>0</SUB>-><SUP>7</SUP>F<SUB>2</SUB> (607nm) transitions.

Hip2 ubiquitin-conjugating enzyme overcomes radiation-induced G2/M arrest

Bae, Y.,Jung, S.H.,Kim, G.Y.,Rhim, H.,Kang, S. Elsevier Biomedical Press 2013 Biochimica et biophysica acta, Molecular cell rese Vol.1833 No.12

Radiation induces cell cycle arrest and/or cell death in mammalian cells. In the present study, we show that Hip2, a ubiquitin-conjugating enzyme, can overcome radiation-induced G2/M cell cycle arrest and trigger the entry into mitosis. Ionizing radiation increased the levels of Hip2 by preventing its degradation but not its gene transcription. The stability of Hip2 in irradiated cells was further confirmed using live cell fluorescence imaging. Flow cytometric and molecular analyses revealed that Hip2 abrogated radiation-induced G2/M arrest, promoting entry into mitosis. Bimolecular fluorescence complementation assays and co-immunoprecipitation experiments showed that Hip2 interacted with and targeted p53 for degradation via the ubiquitin proteasome system, resulting in the activation of cdc2-cyclin B1 kinase to promote mitotic entry. These results contribute to our understanding of the mechanisms that regulate cell cycle progression and DNA damage-induced G2/M checkpoint cellular responses.

레이저에 의한 폐활성슬러지의 전처리에 관한 기초연구

정병길,김대용,최수한,김용윤,성낙창 동아대학교 환경문제연구소 2006 硏究報告 Vol.28 No.1

The objective of this study have been carried out to investigate the solubilization and optimum operation of waste activated sludge by laser for sewage sludge reduction. The concentration of waste activated sludge was adjusted to 0.4%, 0.6%, 0.8%, 1.0%, 1.5% of total solids, respectively. Laser modules were used for pretreatment of waste activated sludge out to use laser module(wavelength : 635~650nm, powermax : <5mW, operating electric power : 6V) in the laser pretreatment. Waste activated sludge was evaluated the temperature, pH, SCOD, SCOD/TCOD rate for the 24 hours. The results showed that SCOD/TCOD rates were increased at the low concentration of total solids, because permeability characteristics of laser were largely interrupted by medium in the sludge. The SCOD/TCOD rates were gradually increased until 1hr of irradiation. At the 0.4% of TS concentration, SCOD/TCOD rates were most effective by increasing sludge temperature from 20.0℃ to 26.3℃, decreased pH from 7.1 to 6.5 and increased concentration of SCOD from 58mg/L to 85mg/L.

Microstructures of laser bonded SiC ceramics with Zr interlayers

Jung, Y.I.,Kim, H.G.,Kim, I.H.,Park, J.Y.,Kim, W.J. North Holland Pub. Co 2014 JOURNAL OF NUCLEAR MATERIALS Vol.455 No.1

SiC plates were bonded using a laser beam scanning method. As an interlayer material, a Zr sheet 0.4mm in thickness was used. Joining was performed at room temperature in air under atmospheric pressure. The interfacial microstructures along with their atomic compositions of the Zr/SiC reaction zone were analyzed. In the Zr side, diffused Si formed ZrSi<SUB>2</SUB>, Zr<SUB>5</SUB>Si<SUB>3</SUB>C<SUB>x</SUB>, and Zr<SUB>4</SUB>Si phases. Carbide transformation was observed (Zr+C→ZrC<SUB>x</SUB>) near the Zr/SiC interface. No crystallographic orientation relationship was found in most of the grains; however, a boundary of ZrSi<SUB>2</SUB> [100] parallel to Zr<SUB>5</SUB>Si<SUB>3</SUB>C<SUB>x</SUB>[011@?1] was found in the observation. In the SiC side, penetrated Zr was found at up to 120μm from the Zr/SiC interface. The diffused Zr formed a silicon-rich metastable phase of ZrSi<SUB>y</SUB> (y>3.3).

Production of ω-hydroxy palmitic acid using CYP153A35 and comparison of cytochrome P450 electron transfer system in vivo

Jung, E.,Park, B. G.,Ahsan, M. M.,Kim, J.,Yun, H.,Choi, K. Y.,Kim, B. G. Springer Science + Business Media 2016 Applied microbiology and biotechnology Vol.100 No.24

<P>Bacterial cytochrome P450 enzymes in cytochrome P450 (CYP)153 family were recently reported as fatty acid omega-hydroxylase. Among them, CYP153As from Marinobacter aquaeolei VT8 (CYP153A33), Alcanivorax borkumensis SK2 (CYP153A13), and Gordonia alkanivorans (CYP153A35) were selected, and their specific activities and product yields of omega-hydroxy palmitic acid based on whole cell reactions toward palmitic acid were compared. Using CamAB as redox partner, CYP153A35 and CYP153A13 showed the highest product yields of omega-hydroxy palmitic acid in whole cell and in vitro reactions, respectively. Artificial self-sufficient CYP153A35-BMR was constructed by fusing it to the reductase domain of CYP102A1 (i.e., BM3) from Bacillus megaterium, and its catalytic activity was compared with CYP153A35 and CamAB systems. Unexpectedly, the system with CamAB resulted in a 1.5-fold higher yield of omega-hydroxy palmitic acid than that using A35-BMR in whole cell reactions, whereas the electron coupling efficiency of CYP153A35-BM3 reductase was 4-fold higher than that of CYP153A35 and CamAB system. Furthermore, various CamAB expression systems according to gene arrangements of the three proteins and promoter strength in their gene expression were compared in terms of product yields and productivities. Tricistronic expression of the three proteins in the order of putidaredoxin (CamB), CYP153A35, and putidaredoxin reductase (CamA), i.e., A35-AB2, showed the highest product yield from 5 mM palmitic acid for 9 h in batch reaction owing to the concentration of CamB, which is the rate-limiting factor for the activity of CYP153A35. However, in fed-batch reaction, A35-AB1, which expressed the three proteins individually using three T7 promoters, resulted with the highest product yield of 17.0 mM (4.6 g/L) omega-hydroxy palmitic acid from 20 mM (5.1 g/L) palmitic acid for 30 h.</P>

Phase III Clinical Trial for Immunogenecity and Safety of a New Recombinant Hepatitis B Virus Vaccine (HG-II) in the Newborn

Cho, Y. K 大韓臨床藥理學會 1996 臨床藥理學會誌 Vol.4 No.2

Spectral optical properties of long-range transport Asian dust and pollution aerosols over Northeast Asia in 2007 and 2008

Jung, J.,Kim, Y. J.,Lee, K. Y.,-Cayetano, M. G.,Batmunkh, T.,Koo, J.-H.,Kim, J. Copernicus GmbH 2010 Atmospheric Chemistry and Physics Vol.10 No.12

<P>Abstract. As a part of the IGAC (International Global Atmospheric Chemistry) Mega-cities program, aerosol physical and optical properties were continuously measured from March 2007 to March 2008 at an urban site (37.57° N, 126.94° E) in Seoul, Korea. Spectral optical properties of long-range transported Asian dust and pollution aerosols have been investigated based on the year long measurement data. Optically measured black carbon/thermally measured elemental carbon (BC/EC) ratio showed clear monthly variation with high values in summer and low values in winter mainly due to the enhancement of light attenuation by the internal mixing of EC. Novel approach has been suggested to retrieve the spectral light absorption coefficient (babs) from Aethalometer raw data by using BC/EC ratio. Mass absorption efficiency, σabs (=babs/EC) at 550 nm was determined to be 9.0±1.3, 8.9±1.5, 9.5±2.0, and 10.3±1.7 m2 g−1 in spring, summer, fall, and winter, respectively with an annual mean of 9.4±1.8 m2 g−1. Threshold values to classify severe haze events were suggested in this study. Increasing trend of aerosol single scattering albedo (SSA) with wavelength was observed during Asian dust events while little spectral dependence of SSA was observed during long-range transport pollution (LTP) events. Satellite aerosol optical thickness (AOT) and Hysplit air mass backward trajectory analyses as well as chemical analysis were performed to characterize the dependence of spectral optical properties on aerosol type. Results from this study can provide useful information for studies on regional air quality and aerosol's effects on climate change. </P>

Upregulation of CXCR4 is functionally crucial for maintenance of stemness in drug-resistant non-small cell lung cancer cells

Jung, M-J,Rho, J-K,Kim, Y-M,Jung, J E,Jin, Y B,Ko, Y-G,Lee, J-S,Lee, S-J,Lee, J C,Park, M-J Macmillan Publishers Limited 2013 Oncogene Vol.32 No.2

The hypothesis of cancer stem cells has been proposed to explain the therapeutic failure in a variety of cancers including lung cancers. Previously, we demonstrated acquisition of epithelial–mesenchymal transition, a feature highly reminiscent of cancer stem-like cells, in gefitinib-resistant A549 cells (A549/GR). Here, we show that A549/GR cells contain a high proportion of CXCR4+ cells that are responsible for having high potential of self-renewal activity in vitro and tumorigenicity in vivo. A549/GR cells exhibited strong sphere-forming activity and high CXCR4 expression and SDF-1α secretion compared with parent cells. Pharmacological inhibition (AMD3100) and/or siRNA transfection targeting CXCR4 significantly suppressed sphere-forming activity in A549 and A549/GR cells, and in various non-small cell lung cancer (NSCLC) cell lines. A549/GR cells showed enhanced Akt, mTOR and STAT3 (Y705) phosphorylation. Pharmacological inhibition of phosphatidyl inositol 3-kinase or transfection with wild-type PTEN suppressed phosphorylation of Akt, mTOR and STAT3 (Y705), sphere formation, and CXCR4 expression in A549/GR cells, whereas mutant PTEN enhanced these events. Inhibition of STAT3 by WP1066 or siSTAT3 significantly suppressed the sphere formation, but not CXCR4 expression, indicating that STAT3 is a downstream effector of CXCR4-mediated signaling. FACS-sorted CXCR4+ A549/GR cells formed many large spheres, had self-renewal capacity, demonstrated radiation resistance in vitro and exhibited stronger tumorigenic potential in vivo than CXCR4− cells. Lentiviral-transduction of CXCR4 enhanced sphere formation and tumorigenicity in H460 and A549 cells, whereas introduction of siCXCR4 suppressed these activities in A549/GR cells. Our data indicate that CXCR4+ NSCLC cells are strong candidates for tumorigenic stem-like cancer cells that maintain stemness through a CXCR4-medated STAT3 pathway and provide a potential therapeutic target for eliminating these malignant cells in NSCLC.

OGLE-2016-BLG-0693LB: Probing the Brown Dwarf Desert with Microlensing

Ryu, Y.-H.,Udalski, A.,Yee, J. C.,Albrow, M. D.,Chung, S.-J.,Gould, A.,Han, C.,Hwang, K.-H.,Jung, Y. K.,Shin, I.-G.,Zhu, W.,Cha, S.-M.,Kim, D.-J.,Kim, H.-W.,Kim, S.-L.,Lee, C.-U.,Lee, Y.,Park, B.-G.,P American Astronomical Society 2017 The Astronomical journal Vol.154 No.6

<P>We present an analysis of microlensing event OGLE-2016-BLG-0693, based on the survey-only microlensing observations by the OGLE and KMTNet groups. In order to analyze the light curve, we consider the effects of parallax, orbital motion, and baseline slope, and also refine the result using a Galactic model prior. From the microlensing analysis, we find that the event is a binary composed of a low-mass brown dwarf (49(-18)(+20) Mj) companion and a K- or G-dwarf host, which lies at a distance of 5.0 +/- 0.6 kpc toward the Galactic bulge. The projected separation between the brown dwarf and its host star is less than similar to 5 au, thus it is likely that the brown dwarf companion is located in the brown dwarf desert.</P>

의료용구 품질향상을 위한 연구(Ⅰ) : 일회용 플라스틱 주사기의 잔류가스(E.O) 분석법에 대하여 Determination of the residual E.O in diposable plastic syringes

장영경,최상숙,최보경,이흔파,정경림,김유선,이규식,고인석 국립보건연구원 1992 국립보건원보 Vol.29 No.2