Characteristic polynomial of a generalized complete product of matrices

Hwang, S.G.,Park, J.W. North Holland [etc.] 2011 Linear algebra and its applications Vol.434 No.5

For a simple graph G, let G@? denote the complement of G relative to the complete graph and let P<SUB>G</SUB>(x)=det(xI-A(G)) where A(G) denotes the adjacency matrix of G. The complete product G@?H of two simple graphs G and H is the graph obtained from G and H by joining every vertex of G to every vertex of H. In [2]P<SUB>G@?H</SUB>(x) is represented in terms of P<SUB>G</SUB>, P<SUB>G@?</SUB>, P<SUB>H</SUB> and P<SUB>H@?</SUB>. In this paper we extend the notion of complete product of simple graphs to that of generalized complete product of matrices and obtain their characteristic polynomials.

Gα₁₂ gep oncogene deregulation of p53-responsive microRNAs promotes epithelial–mesenchymal transition of hepatocellular carcinoma

Yang, Y M,Lee, W H,Lee, C G,An, J,Kim, E-S,Kim, S H,Lee, S-K,Lee, C H,Dhanasekaran, D N,Moon, A,Hwang, S,Lee, S J,Park, J-W,Kim, K M,Kim, S G Macmillan Publishers Limited 2015 Oncogene Vol.34 No.22

Hepatocellular carcinoma (HCC) has a poor prognosis owing to aggressive phenotype. Gα<SUB>12</SUB> gep oncogene product couples to G-protein-coupled receptors, whose ligand levels are frequently increased in tumor microenvironments. Here, we report Gα<SUB>12</SUB> overexpression in human HCC and the resultant induction of zinc-finger E-box-binding homeobox 1 (ZEB1) as mediated by microRNA deregulation. Gα<SUB>12</SUB> expression was higher in HCC than surrounding non-tumorous tissue. Transfection of Huh7 cell with an activated mutant of Gα<SUB>12</SUB> (Gα<SUB>12</SUB>QL) deregulated microRNA (miRNA or miR)-200b/a/429, -194-2/192 and -194-1/215 clusters in the miRNome. cDNA microarray analyses disclosed the targets affected by Gα<SUB>12</SUB> gene knockout. An integrative network of miRNAs and mRNA changes enabled us to predict ZEB1 as a key molecule governed by Gα<SUB>12</SUB>. Decreases of miR-200a/b, -192 and -215 by Gα<SUB>12</SUB> caused ZEB1 induction. The ability of Gα<SUB>12</SUB> to decrease p53 levels, as a result of activating protein-1 (AP-1)/c-Jun-mediated mouse double minute 2 homolog induction, contributed to transcriptional deregulation of the miRNAs. Gα<SUB>12</SUB>QL induced ZEB1 and other epithelial–mesenchymal transition markers with fibroblastoid phenotype change. Consistently, transfection with miR-200b, -192 or -215 mimic prevented the ability of Gα<SUB>12</SUB>QL to increase tumor cell migration/invasion. In xenograft studies, sustained knockdown of Gα<SUB>12</SUB> decreased the overall growth rate and average volume of tumors derived from SK-Hep1 cell (mesenchymal-typed). In HCC patients, miR-192, -215 and/or -200a were deregulated with microvascular invasion or growth advantage. In the HCC samples with higher Gα<SUB>12</SUB> level, a correlation existed in the comparison of relative changes of Gα<SUB>12</SUB> and ZEB1. In conclusion, Gα<SUB>12</SUB> overexpressed in HCC causes ZEB1 induction by deregulating p53-responsive miRNAs, which may facilitate epithelial–mesenchymal transition and growth of liver tumor. These findings highlight the significance of Gα<SUB>12</SUB> upregulation in liver tumor progression, implicating Gα<SUB>12</SUB> as an attractive therapeutic target.

Radiation promotes invasiveness of non-small-cell lung cancer cells through granulocyte-colony-stimulating factor

Cui, Y-H,Suh, Y,Lee, H-J,Yoo, K-C,Uddin, N,Jeong, Y-J,Lee, J-S,Hwang, S-G,Nam, S-Y,Kim, M-J,Lee, S-J Macmillan Publishers Limited 2015 Oncogene Vol.34 No.42

Despite ionizing radiation (IR) is being widely used as a standard treatment for lung cancer, many evidences suggest that IR paradoxically promotes cancer malignancy. However, its molecular mechanisms underlying radiation-induced cancer progression remain obscure. Here, we report that exposure to fractionated radiation (2 Gy per day for 3 days) induces the secretion of granulocyte-colony-stimulating factor (G-CSF) that has been commonly used in cancer therapies to ameliorate neutropenia. Intriguingly, radiation-induced G-CSF promoted the migratory and invasive properties by triggering the epithelial–mesenchymal cell transition (EMT) in non-small-cell lung cancer cells (NSCLCs). By irradiation, G-CSF was upregulated transcriptionally by β-catenin/TCF4 complex that binds to the promoter region of G-CSF as a transcription factor. Importantly, irradiation increased the stability of β-catenin through the activation of PI3K/AKT (phosphatidylinositol 3-kinase/AKT), thereby upregulating the expression of G-CSF. Radiation-induced G-CSF is recognized by G-CSFR and transduced its intracellular signaling JAK/STAT3 (Janus kinase/signal transducers and activators of transcription), thereby triggering EMT program in NSCLCs. Taken together, our findings suggest that the application of G-CSF in cancer therapies to ameliorate neutropenia should be reconsidered owing to its effect on cancer progression, and G-CSF could be a novel therapeutic target to mitigate the harmful effect of radiotherapy for the treatment of NSCLC.

여대생의 우울, 스트레스와 문제도박과의 관계

하주희,차민주,조에스더,조세빈,홍소리,황정민,박지윤,강하영,노규상 이화여자대학교 간호과학대학 2015 이화간호학회지 Vol.- No.49

Purpose: The purpose of this study was to learn about problem-gambling level, depression and stress among female college students. Method: In this cross-sectional design study, a convenient sample of 325 female college students were recruited between September and October, 2014. Measurement used for this study were the CPGI(Canadian Problem Gambling Index), the CES-D(Center for Epidemiologic Studies Depression Scale), and the Life stress scale for college students. Data were statistically analyzed using descriptive statistics, t-test, ANOVA and chi-square test. Result: About 58.5 percent of the participants had experience of gambling; lottery was the most frequently used gambling among participants. 36 participants(11.1%) were problem gamblers. Relationship of smoking status to problem gambler group was statistically significant. There were statistically significant relationships among problem-gambling level(Non-problem, Low-risk, Moderate-risk, High-risk), depression and stress. The problem gambler group had significantly higher trait stress scores compared to the normal group. Conclusion: Problem gambling was a risk factor for both depression and stress among female college students. The proposals of this study are as follows; first, in depth-research are required with more expanded sampling as sample of this study was conveniently gathered, it is hard to generalize the result. Second, a problem gambling prevention program is recommended for low-risk problem gamblers as they have risk to become problem gambler later. Third, nursing interventions for problem gamblers should be investigated with regard to depression and stress level.

Preparation of Bimodal Porous Carbon Supported PtRu Catalysts for Fuel Cells

Hwang, S.,Park, G.-G.,Yim, S.-D.,Park, S.-H.,Yang, T.-H.,Kim, H.,Kim, C.-S. WILEY-VCH Verlag 2010 FUEL CELLS -WEINHEIM- Vol.10 No.2

<P>In this work, we synthesised the bimodal porous carbon supported electro-catalyst as a novel catalyst for fuel cells. For this purpose, the bimodal porous carbons with different pore sizes were prepared by imprinting method. Three kinds of bimodal porous carbons were fabricated by using the silica spheres with diameters of ca. 50, 100 and 300 nm and SBA-15 particle having 200–250 nm diameter and 700–900 nm length as templates. The BET surface areas of the bimoal porous carbons were determined to be 235–294 m<SUP>2</SUP> g<SUP>–1</SUP>, which are similar to that of Vulcan XC72. To evaluate the electro-catalytic activity, the PtRu nanoparticles of ca. 1.9–2.6 nm were loaded on the bimodal porous carbon supports. The PtRu/C100, synthesised by using SBA-15 and 100 nm silica sphere, had the higher electrochemical surface area (ECSA) and the lower on-set potential and showed comparable performance with the commercial catalyst.</P>

HECTOMAP AND HORIZON RUN 4: DENSE STRUCTURES AND VOIDS IN THE REAL AND SIMULATED UNIVERSE

Hwang, Ho Seong,Geller, Margaret J.,Park, Changbom,Fabricant, Daniel G.,Kurtz, Michael J.,Rines, Kenneth J.,Kim, Juhan,Diaferio, Antonaldo,Zahid, H. Jabran,Berlind, Perry,Calkins, Michael,Tokarz, Susa American Astronomical Society 2016 The Astrophysical journal Vol.818 No.2

<P>HectoMAP is a dense redshift survey of red galaxies covering a 53 deg(2) strip of the northern sky. HectoMAP is 97% complete for galaxies with r < 20.5, (g-r) > 1.0, and (r -i) > 0.5. The survey enables tests of the physical properties of large-scale structure at intermediate redshift against cosmological models. We use the Horizon Run 4, one of the densest and largest cosmological simulations based on the standard. Cold Dark Matter (Lambda CDM) model, to compare the physical properties of observed large-scale structures with simulated ones in a volume-limited sample covering 8 x 10(6) h(-3) Mpc(3) in the redshift range 0.22 < z < 0.44. We apply the same criteria to the observations and simulations to identify over-and under-dense large-scale features of the galaxy distribution. The richness and size distributions of observed over-dense structures agree well with the simulated ones. Observations and simulations also agree for the volume and size distributions of under-dense structures, voids. The properties of the largest over-dense structure and the largest void in HectoMAP are well within the distributions for the largest structures drawn from 300 Horizon Run 4 mock surveys. Overall the size, richness and volume distributions of observed large-scale structures in the redshift range 0.22 < z < 0.44 are remarkably consistent with predictions of the standard Lambda CDM model.</P>

sediment toxicity assessment in the interidal flat zone of the middle west coast of korea

G,S,Hwang,G,Dave,E,Nilsson,K,Kim 한국환경보건학회 2004 한국환경보건학회지 Vol.30 No.4

Muricauda olearia sp. nov., isolated from crude-oil-contaminated seawater, and emended description of the genus Muricauda

Hwang, C. Y.,Kim, M. H.,Bae, G. D.,Zhang, G. I.,Kim, Y. H.,Cho, B. C. Microbiology Society 2009 International journal of systematic and evolutiona Vol.59 No.8

<P>A Gram-staining-negative, rod-shaped and non-motile bacterium, designated CL-SS4T, was isolated from crude-oil-contaminated seawater from the west coast of Korea and was investigated by means of a polyphasic taxonomic approach. Strain CL-SS4T grew optimally at 25-30 degrees C, at pH 6.8-7.7 and in the presence of 2-3% sea salts. The major fatty acids were iso-C17:0 3-OH, iso-C15:0 and iso-C15:1 G. The major isoprenoid quinone was MK-6. The DNA G+C content was 50.7 mol%. Analysis of the 16S rRNA gene sequence of strain CL-SS4T revealed that it was a member of the genus Muricauda, sharing 95.7-96.9% sequence similarity with the type strains of Muricauda species and being most closely related to Muricauda aquimarina SW-63T. Phylogenetic analyses based on 16S rRNA gene sequences confirmed that strain CL-SS4T formed a deep lineage related to the genus Muricauda. Strain CL-SS4T was distinguishable from recognized Muricauda species on the basis of differential phenotypic characteristics and DNA G+C content. Based on these results, it is proposed that strain CL-SS4T represents a novel species of the genus Muricauda, for which the name Muricauda olearia sp. nov. is proposed. An emended description of the genus Muricauda is also proposed. The type strain is CL-SS4T (=KCCM 90075T=JCM 15563T).</P>

Pharmacokinetics and pharmacokinetic/pharmacodynamic integration of orbifloxacin in Korean Hanwoo cattle

ELIAS, G.,LEE, J.-S.,HWANG, M.-H.,PARK, Y.-S.,CHO, K.-H.,KIM, Y.-H.,PARK, S.-C. Blackwell Publishing Ltd 2009 Journal of veterinary pharmacology and therapeutic Vol.32 No.3

<P>The pharmacokinetics and pharmacodynamics of orbifloxacin were studied in six clinically healthy Hanwoo cows after intravenous (i.v.) and intramuscular (i.m.) administration at a dose of 3 mg/kg. Orbifloxacin concentrations were determined by high performance liquid chromatography with fluorescence detection. Steady-state volume of distribution and clearance of orbifloxacin after i.v. administration were 0.92 L/kg and 0.24 L/h·kg, respectively. Following i.m. administration, a slow and complete absorption with absolute bioavailability of 101.4%, and a maximum concentration (<I>C</I><SUB>max</SUB>) of 1.17 &mgr;g/mL at 1.04 h were observed. The <I>in vitro</I> serum protein binding was 14.76%. The <I>in vitro</I> antibacterial activity of orbifloxacin against a pathogenic strain of <I>Mannheimia haemolytica</I> (<I>M. haemolytica</I>), <I>Escherichia coli</I> (<I>E. coli</I>) and <I>Staphylococcus aureus</I> (<I>S. aureus</I>) was determined<I>.</I> The <I>ex vivo</I> activity of orbifloxacin against <I>M. haemolytica</I> strain was also determined<I>,</I> and these data were integrated with the <I>ex vivo</I> bacterial counts to establish <I>AUC</I><SUB>24h</SUB>/<I>MIC</I> values producing bacteriostatic action, bactericidal action and elimination of bacteria. Mean values were 32.7, 51.6 and 102.6 h, respectively. From these data, we predict that orbifloxacin, when administered i.m. at a dosage of 2.5–5 mg/kg once a day, would be effective against bovine pathogens, such as <I>M. haemolytica.</I> Additional studies may be needed to confirm its efficacy in a clinical setting, and to evaluate the penetration of the drug in diseased tissues.</P>

NiFe / Cr 다층박막의 층수와 자기이방성에 따른 자기저항특성

황도근(D. G. Hwang),이상석(S. S. Lee),박창만(C. M. Park),이기암(K. A. Lee) 한국자기학회 1995 韓國磁氣學會誌 Vol.5 No.3

Glass\Cr_(40Å)\[Cr_(10Å)\NiFe_(50Å)]_N multilayers (number of layer N = 1, 2, 3, 4, 5, 6, 10) were made by dc magnetron sputtering under magnetic anisotropy of 200 G. Magnetoresistance curve MR(xx), MR(xy) were measured for the parallel and perpendicular current direction to external magnetic field. MR(xx) curves for the number of layer N=1, 5, 10 were almost became about zero percent, however the curves of other numbers appeared the phenomena of positive magnetoresistance that the resistance increased to external magnetic field, and the irregular and reversed curves in the vicinity of H=0 Oe.