Effects of Y₂O₃ additions on the oxygen diffusion in top-seeded melt growth processed YBa₂Cu₃O_7-y superconductors

Jun, B.H.,Jung, S.A.,Park, S.D.,Park, B.J.,Han, Y.H.,Kim, C.J. North-Holland 2011 Physica. C, Superconductivity Vol.471 No.21

To understand the effect of Y<SUB>2</SUB>BaCuO<SUB>5</SUB> (Y211)/YBa<SUB>2</SUB>Cu<SUB>3</SUB>O<SUB>7-y</SUB> (Y123) interfaces on the oxygen diffusion in single grain YBa<SUB>2</SUB>Cu<SUB>3</SUB>O<SUB>7-y</SUB> superconductors, single grain Y123 superconductors with 0.05 and 0.3moles of Y<SUB>2</SUB>O<SUB>3</SUB> additions were fabricated by a top-seeded melt growth (TSMG) process. Y123 compacts with Y<SUB>2</SUB>O<SUB>3</SUB> additions were subjected to melt growth heating cycles with a cooling rate of 1<SUP>o</SUP>C/h through a peritectic temperature (1015<SUP>o</SUP>C) and then annealed at 450<SUP>o</SUP>C for 200h in flowing oxygen. The superconducting temperature (T<SUB>c</SUB>) and critical current density (J<SUB>c</SUB>) were estimated for the three different regions (top surface (s), intermediate (i) and center (c)) of samples. The amount of Y211/Y123 interface area in single grain Y123 superconductors was successfully controlled by Y<SUB>2</SUB>O<SUB>3</SUB> additions. The T<SUB>c</SUB> values of s regions were higher than those of i and c regions, which indicates the presence of more oxygen at the sample surfaces. In addition, the T<SUB>c</SUB> values of i and c regions of the Y123 sample with 0.3mole Y<SUB>2</SUB>O<SUB>3</SUB> addition were higher than those of the same regions of the Y123 sample with 0.05mole Y<SUB>2</SUB>O<SUB>3</SUB> addition due to the promoted oxygen diffusion through Y211/Y123 interfaces and other related defects. In spite of the promoted oxygen diffusion by Y<SUB>2</SUB>O<SUB>3</SUB> addition, the large T<SUB>c</SUB> difference among the regions still existed, which suggests sluggish oxygen diffusion into single Y123 grains.

Effects of calcium doping on the superconducting properties of top-seeded melt growth processed Y_1.5Ba_2-xCa_xCu₃O_y superconductors

Park, S.D.,Kim, H.J.,Park, B.J.,Han, Y.H.,Jun, B.H.,Lee, J.S.,Kim, C.J. North-Holland 2011 Physica. C, Superconductivity Vol.471 No.21

The effect of calcium doping on the superconducting properties of top seeded melt growth (TSMG) processed Y<SUB>1.5</SUB>Ba<SUB>2-x</SUB>Ca<SUB>x</SUB>Cu<SUB>3</SUB>O<SUB>y</SUB> superconductors was studied in terms of calcium content (X<SUB>ca</SUB>). YBa<SUB>2-x</SUB>Ca<SUB>x</SUB>Cu<SUB>3</SUB>O<SUB>7-δ</SUB> (X<SUB>ca</SUB>=0, 0.005, 0.01, 0.02, 0.04, 0.1, 0.3) powders were synthesized by the powder calcination method. YBa<SUB>2-x</SUB>Ca<SUB>x</SUB>Cu<SUB>3</SUB>O<SUB>7-δ</SUB> powders were mixed with 0.25mole Y<SUB>2</SUB>O<SUB>3</SUB> powder and 1wt.% CeO<SUB>2</SUB> as Y<SUB>2</SUB>BaCuO<SUB>5</SUB> (Y211) refiner, and finally made into Y<SUB>1</SUB>.<SUB>5</SUB>Ba<SUB>2-x</SUB>Ca<SUB>x</SUB>Cu<SUB>3</SUB>O<SUB>y</SUB> (Y1.5)+1wt.% CeO<SUB>2</SUB> composition. The single Y123 growth on the top surface was observed up to X<SUB>ca</SUB>=0.1, while the multiple Y123 growth was observed at X<SUB>ca</SUB>≥0.1. The superconducting transition temperature (T<SUB>c</SUB>) and critical current density (J<SUB>c</SUB>) of TSMG processed Y1.5 samples were inversely proportional to X<SUB>ca</SUB>. The Y211 size increased with increasing X<SUB>ca</SUB> due to the enhancement of Y211 coarsening by calcium doping. No Y211 refining effect by CeO<SUB>2</SUB> was observed in the calcium doped samples. The T<SUB>c</SUB> and J<SUB>c</SUB> decrease by calcium doping are likely to be due to the calcium incorporation with the Y123 lattice and formation of coarse Y211 particles.

Silencing of homeobox B9 is associated with down-regulation of CD56 and extrathyroidal extension of tumor in papillary thyroid carcinoma

Kim, J.H.,Kim, Y.H.,Han, J.H.,Lee, K.B.,Sheen, S.S.,Lee, J.,Soh, E.Y.,Park, T.J. W. B. Saunders Co ; Centrum Philadelphia 2012 Human pathology Vol.43 No.8

Papillary thyroid carcinoma is the most common type of thyroid malignancy, and CD56, a neural cell adhesion molecule, is typically down-regulated in almost all cases of papillary thyroid carcinoma. Homeobox B9 is a transcription factor, belongs to the products of the homeobox transcription factor gene family, and has been known to regulate transcription of CD56 and to promote tumorigenicity and metastasis in some malignancies. In this study, we investigated the expression and relation of homeobox B9 to reduced expression of CD56 in papillary thyroid carcinomas and also a relationship between their expression and clinicopathologic parameters. Therefore, we performed CD56 and homeobox B9 immunohistochemical staining on 72 papillary thyroid carcinomas and Western blotting on 31 papillary thyroid carcinomas. CD56 protein staining revealed that it was reduced or absent in 65 papillary thyroid carcinomas (90.3%) and was related to silencing of homeobox B9 (77.8%) (P = .003). The loss of homeobox B9 expression was associated with extrathyroidal extension (P = .002), pathologic stage of tumor (P = .01), and age older than 45 years (P = .032). However, the CD56 staining did not reveal any significant relationship with clinicopathologic features (P > .05). In conclusion, reduced expression of CD56 is associated with homeobox B9 in papillary thyroid carcinomas. Furthermore, silencing of homeobox B9 is more common in older age and is linked to extrathyroidal extension and advanced pathologic stage of papillary thyroid carcinoma.

Antiviral activity of KR-23502 targeting nuclear export of influenza B virus ribonucleoproteins

Jang, Y.,Lee, H.W.,Shin, J.S.,Go, Y.Y.,Kim, C.,Shin, D.,Malpani, Y.,Han, S.B.,Jung, Y.S.,Kim, M. Elsevier/North-Holland 2016 ANTIVIRAL RESEARCH Vol.134 No.-

<P>The spiro compound 5,6-dimethyl-3H,3'H-spiro(benzofuran-2,1'-isobenzofuran)-3,3'-dione (KR-23502) has antiviral activity against influenza A and more potently B viruses. The aim of this study is to elucidate its mechanism of action. Subcellular localization and time-course expression of influenza B viral proteins, nucleoprotein (NP) and matrix protein 1 (M1), showed that KR-23502 reduced their amounts within 5 h post-infection. Early steps of virus life cycle, including virus entry, nuclear localization of NP and viral RNA-dependent RNA replication, were not affected by KR-23502. Instead it interrupted a later event corresponding to nuclear export of NP and M1 proteins. Delivery of viral ribonucleoprotein (vRNP)-M1 complex has been known to be mediated by the viral nuclear export protein (NEP) through interaction with cellular chromosomal maintenance 1 (CRM1) protein. In this study, we experimentally demonstrated that the compound targets the nuclear export of vRNP. Moreover, a single mutation (aspartate to glycine) at amino acid position 54 in M1 [M1(D54G)] was detected after 18 passages in the presence of KR-23502 with a 2-fold increase in 50% effective concentration indicating that this compound has a relatively high genetic barrier to resistance. Interestingly, it was observed that proteasome-mediated degradation of M1 (D54G) was attenuated by KR-23502. In conclusion, we suggest that KR-23502 shows its anti-influenza activity by downregulating NEP/CRM1-mediated nuclear export of influenza vRNP and M1. KR-23502 provides a core chemical skeleton for further structure-based design of novel antivirals against influenza viruses. (C) 2016 Elsevier B.V. All rights reserved.</P>

Satisfaction with mammography in the National Cancer Screening Programme participants of age 40s in Korea

JEON, B.Y.,LEE, H‐,Y.,PARK, E‐,C.,CHOI, K.S.,JUN, J.K.,KIM, Y.,HAN, M.A.,YOON, N‐,H.,KIM, E.J.,JEON, S.M. Blackwell Publishing Ltd 2011 European journal of cancer care Vol.20 No.6

<P>JEON B.Y., LEE H‐Y., PARK E‐C., CHOI K.S., JUN J.K., KIM Y., HAN M.A., YOON N‐H., KIM E.J. & JEON S.M. (2011) <I>European Journal of Cancer Care</I><B>20</B>, 803–809</P><P><B>Satisfaction with mammography in the National Cancer Screening Programme participants of age 40s in Korea</B></P><P>The aim of this study was to evaluate satisfaction with the National Cancer Screening Programme of mammography in Korea and to examine the association between subscales of satisfaction and general satisfaction. We conducted a cross‐sectional telephone survey for women who had obtained a National Cancer Screening Programme mammographic screening at general hospitals between May and October 2008. The present study included 2005 women in their forties. We performed multivariate linear regression using dependent variable as general satisfaction and independent variables as subscales of satisfaction, such as pre‐screening information transfer, staff interpersonal skills, physical surroundings and results reporting. Participants were stratified according to the result of their mammogram as negative or positive. Mean score of satisfaction was above 2.5 of 4 for all subscales. Women who received positive results were less satisfied with all of subscale factors. Staff interpersonal skills were the most important factor that contributed to general satisfaction. Future efforts such as staff training programme of communication/attitude skills, ensuring privacy and explanation of possible discomfort of the screening would be needed.</P>

CD19 signalling improves the Epstein–Barr virus-induced immortalization of human B cell

Hur, D. Y.,Lee, M. H.,Kim, J. W.,Kim, J.-H.,Shin, Y. K.,Rho, J. K.,Kwack, K. B.,Lee, W. J.,Han, B. G. Blackwell Science Ltd 2005 Cell proliferation Vol.38 No.1

<P>Abstract. </P><P>Epstein–Barr virus (EBV) infection <I>in vitro</I> immortalizes primary B cells and generates B lymphoblastoid cell lines (LCLs). These EBV-LCLs have been used for several purposes in immunological and genetic studies, but some trials involving these transformations fail for unknown reasons, and several EBV-LCLs do not grow in normal culture. In this study, we improved the immortalization method by CD19 and B-cell receptor (BCR) co-ligation. This method shortens the time required for the immortalization and generation of EBV-LCLs but does not alter the cell phenotype of the LCLs nor the expression of the EBV genes. In particular, the CD19 and BCR co-ligation method was found to be the most effective method examined. EBV-infected B cells induced by CD19 and/or BCR ligation expressed the intracellular latent membrane protein LMP-1 earlier than EBV-infected B cells, and the expression of intracellular LMP-1 was found to be closely related to the time of immortalization. These results suggest that the modified method, using CD19 and/or BCR ligation, may efficiently generate EBV-LCLs, by expressing intracellular LMP-1 at an early stage.</P>

Draft Genome Sequence of the Biocontrol Bacterium Pseudomonas putida B001, an Oligotrophic Bacterium That Induces Systemic Resistance to Plant Diseases

Park, J. Y.,Han, S. H.,Lee, J. H.,Han, Y. S.,Lee, Y. S.,Rong, X.,McSpadden Gardener, B. B.,Park, H.-S.,Kim, Y. C. American Society for Microbiology 2011 Journal of Bacteriology Vol.193 No.23

<P>Pseudomonas putida B001 is a rhizobacterium that was isolated on the basis of its abilities to grow under low-nutrient conditions and induce systemic resistance against bacterial, fungal, and viral diseases of plants. Here we report the draft genome sequence and automatic annotation of strain B001. Comparison of this sequence to the sequenced genome of P. putida KT2440 points to a subset of gene functions that may be related to the defense-inducing functions of B001.</P>

Effects of Cu and B addition on microstructure and mechanical properties of high-strength bainitic steels

Shin, S.Y.,Han, S.Y.,Hwang, B.,Lee, C.G.,Lee, S. Elsevier Sequoia 2009 Materials science & engineering. properties, micro Vol.517 No.1

Effects of Cu and B addition on microstructure and mechanical properties of high-strength bainitic steels were investigated in this study. Six kinds of steels were fabricated by controlling the amount of Cu and B addition, and their microstructures and tensile and Charpy impact properties were investigated. Their effective grain sizes were also characterized by the electron back-scatter diffraction analysis. The tensile test results indicated that the B- or Cu-containing steels had the higher yield and tensile strengths than the B- or Cu-free steels because their volume fractions of acicular ferrite and martensite were quite high. The B- or Cu-free steels had the higher upper shelf energy than the B- or Cu-containing steels because of their lower volume fraction of martensite. In the steel containing 10ppm B without Cu, the best combination of high strengths, high upper shelf energy, and low energy transition temperature could be obtained by the decrease in effective grain size due to the presence of acicular ferrite having fine effective grain size.

Particle distribution in melt-processed Y_1.5 Ba₂Cu₃O_x superconductors with BaCeO₃ addition

Youn, J.S.,No, K.,Kim, Y.H.,Mahmood, A.,Jun, B.H.,Han, Y.H.,Sung, T.H.,Kim, C.J. North-Holland 2009 Physica. C, Superconductivity Vol.469 No.15

To understand the effect of BaCeO<SUB>3</SUB> on a Y<SUB>2</SUB>BaCuO<SUB>5</SUB> (Y211) distribution, Y<SUB>1.5</SUB>Ba<SUB>2</SUB>Cu<SUB>3</SUB>O<SUB>x</SUB> (Y1.5) superconductors with/without 1wt.% BaCeO<SUB>3</SUB> additions were prepared by a top-seeded melt-textured growth (TSMG) process. Two different BaCeO<SUB>3</SUB> powders (as-synthesized (coarse powder) and an attrition-milled (fine powder)) were used and the size effect was compared with that obtained from a Y1.5 sample with no addition. A refinement of the Y211 particles was achieved for both the as-synthesized and attrition-milled BaCeO<SUB>3</SUB> additions. The distribution of the Y211 particles was most uniform in the Y1.5 sample prepared with the attrition-milled BaCeO<SUB>3</SUB> powder due to the reduced size of the Y211-free regions by the fine size BaCeO<SUB>3</SUB> addition. The highest J<SUB>c</SUB> was achieved in the Y1.5 sample prepared with the attrition-milled BaCeO<SUB>3</SUB> powder. The J<SUB>c</SUB> result agreed well with the microstructure variations by the addition of BaCeO<SUB>3</SUB> powders.

Effective pore control and critical current density in liquid infiltration growth processed Y-123 superconductors with Ag addition

Mahmood, A,Jun, B-H,Han, Y H,Kim, C-J IOP Publishing Ltd 2010 Superconductor science & technology Vol.23 No.6

<P>The effect of a sintered density (open porosity) of Y<SUB>2</SUB>BaCuO<SUB>5</SUB> (Y211) pre-forms on the final porosity and Y211 size within Y Ba<SUB>2</SUB>Cu<SUB>3</SUB>O<SUB>7 − <I>y</I></SUB> (Y-123) products was systematically studied in liquid infiltration growth (LIG) processed Y-123 bulk superconductors with Ag addition. To prepare Y211 pre-forms of various densities, Y211 powder compacts were sintered in air at various temperatures of 900–1200 °C. The single-grain Y-123 bulk superconductors were fabricated by the LIG process with top seeding. It was found that the porosity of the final Y-123 product was fairly dependent on the Y211 pre-form density. When a Y211 pellet of a high density was used as a pre-form for the LIG process, the porosity of the final Y-123 product was greatly reduced. In addition to the reduced porosity, the enhanced Y211 refinement was achieved for the Y-123 product prepared using the dense Y211 pre-form, resulting in the improved critical current density (<I>J</I><SUB>c</SUB>). The Ag addition was also helpful in eliminating the spherical pores through pore filling with a silver melt. The pore elimination and Y211 refinement mechanism in the LIG-processed Y-123 bulks were explained in terms of the liquid capillary movement and Ag melt and particle coarsening at the (Y 211 + melt) state.</P>