Effects of $BaCO_3$ purity on the superconducting properties of top seeded melt growth processed $Y_{1+x}Ba_2Cu_3O_y$ superconductors

Choi, J.S.,Park, S.D.,Jun, B.H.,Han, Y.H.,Sung, T.H.,Choo, K.N.,Kim, C.J. The Korean Society of Superconductivity and Cryoge 2009 한국초전도저온공학회논문지 Vol.11 No.2

Effects of $BaCO_3$ purity on the superconducting properties of top seeded melt growth (TSMG) processed $Y_{1+x}Ba_2Cu_3O_{7-y}$ (Y1+x, x=0.1 and 0.2) superconductors were investigated. $YBa_2Cu_3O_{7-y}$ (Y123) powder prepared using $BaCO_3$ with 99.75% purity and commercially available Y123 powder of 99.9% were used for the fabrication of single Y123 grain superconductors. $T_c$ values of the Y1+x samples prepared using low purity Y123 powder were slightly lower than those of the samples prepared using a high purity powder. In addition to the lower $T_c$, an anomalous peak effect in the intermediate magnetic fields was observed in Y1+x samples prepared using the low purity $BaCO_3$ powder. The slight decrease in $T_c$ and the anomalous peak effect are ascribed to the possible incorporation of a Y123 phase with impurity elements such as strontium and calcium included in the $BaCO_3$powder of 99.7%. The result suggests that the low purity $BaCO_3$ powder of a low price can be used as a raw power for the fabrication of single grain YBCO bulk superconductors.

돼지 H-FABP 유전자의 다형성 및 경제 형질과의 연관성 구명

최봉환,김태헌,이지웅,조용민,이혜영,조병욱,정일정 한국동물자원과학회 2003 한국축산학회지 Vol.45 No.5

The purpose of this study was to detect association between genetic variation and economic trait in the porcine heart type fatty acid-binding protein gene as a candidate gene for the traits related with growth and meat quality in pigs. The H-FABP is a 15-kDa protein expressed in several tissues with high demand for fat metabolism such as cardiac and skeletal muscle and lactating mammary gland. H-FABP is small intracellular protein involved in fatty acid transport from the plasma membrane to the site of β-oxidation and/or triacylglycerol or phospholipid synthesis. In this study, H-FABP PCR-RFLP was performed in F_(2) population composed of 214 individuals form an intercross between Korean Native Boars and Landrace sows. PCR products form tow primer sets within H-FABP gene were amplified in 850bp and 700bp. Digestion of PCR products with the restriction digestion enzymes HaeⅢ and Hinf Ⅰ, revealed fragment length polymorphisms(RFL. Ps). The genotype frequencies from H-FABP/HaeⅢ was .29 for genotype DD, .53 for genotype Dd, and .15 for genotype dd, respectively. The genotype frequencies of HH, Hh, and hh from H-FABP(hinf Ⅰ was .38, .41, and .20, respectively, in the population.Relationships between their genotypes and economic traits were estimated. In H-FABP/HaeⅢ locus, there were specific genotypes(Dd and dd) associated with economic traits such as body weight. In H-FABP/Hinf Ⅰ Iocus, Genotypes of HH and Hh associated with growth traits such as body weights at 5, 12, and 30 week of age (p<.05 or p<.001) and back fat thickness, body fat including abdominal and trimmed fat (p<.001) and intramuscular fat(p<.05). The 'H'allele was positivecly associated with gaining of body weight and fatness deposition. In conclusion, a significant association of the H-FABP gene from its genetic variation was found on body weight, intramuscular fat and backfat thickness.

Genetic relationship of H3 subtype avian influenza viruses isolated from domestic ducks and wild birds in Korea and their pathogenic potential in chickens and ducks

Choi, J.G.,Kang, H.M.,Kim, M.C.,Paek, M.R.,Kim, H.R.,Kim, B.S.,Kwon, J.H.,Kim, J.H.,Lee, Y.J. Elsevier Scientific Pub. Co 2012 Veterinary microbiology Vol.155 No.2

The H3 subtype avian influenza virus (AIV) is one of the most frequently isolated subtypes in domestic ducks, live poultry markets, and wild birds in Korea. In 2002-2009, a total of 45 H3 subtype AIVs were isolated from the feces of clinically normal domestic ducks (n=28) and wild birds (n=17). The most prevalent subtypes in domestic ducks were H3N2 (35.7%), H3N6 (35.7%), H3N8 (25.0%), and H3N1 (3.6%, novel subtype in domestic duck in Korea). In contrast, H3N8 (70.6%) is the most prevalent subtype in wild birds in Korea. In the phylogenetic analysis, HA genes of the Korean H3 AIVs were divided into 3 groups (Korean duck, wild bird 1, and wild bird 2) and all viruses of duck origin except one were clustered in a single group. However, other genes showed extensive diversity and at least 17 genotypes were circulating in domestic ducks in Korea. When the analysis expanded to viruses of wild bird origin, the genetic diversity of Korean H3 AIVs became more complicated. Extensive reassortments may have occurred in H3 subtype influenza viruses in Korea. When we inoculated chickens and ducks with six selected viruses, some of the viruses replicated efficiently without pre-adaptation and shed a significant amount of viruses through oropharyngeal and cloacal routes. This raised concerns that H3 subtype AIV could be a new subtype in chickens in Korea. Continuous surveillance is needed to prepare the advent of a novel subtype AIV in Korea.

Neural stem cells injured by oxidative stress can be rejuvenated by GV1001, a novel peptide, through scavenging free radicals and enhancing survival signals

Park, H.H.,Yu, H.J.,Kim, S.,Kim, G.,Choi, N.Y.,Lee, E.H.,Lee, Y.J.,Yoon, M.Y.,Lee, K.Y.,Koh, S.H. Elsevier BV 2016 NeuroToxicology Vol.55 No.-

<P>Oxidative stress is a well-known pathogenic mechanism of a diverse array of neurological diseases, and thus, numerous studies have attempted to identify antioxidants that prevent neuronal cell death. GV1001 is a 16-amino-acid peptide derived from human telomerase reverse transcriptase (hTERT). Considering that hTERT has a strong antioxidant effect, whether GV1001 also has an antioxidant effect is a question of interest. In the present study, we aimed to investigate the effects of GV1001 against oxidative stress in neural stem cells (NSCs). Primary culture NSCs were treated with different concentrations of GV1001 and/or hydrogen peroxide (H2O2) for various time durations. The H2O2 decreased the viability of the NSCs in a concentration-dependent manner, with 200 mu M H2O2 significantly decreasing both proliferation and migration. However, treatment with GV1001 rescued the viability, proliferation and migration of H2O2 injured NSCs. Consistently, free radical levels were increased in rat NSCs treated with H2O2, while co-treatment with GV1001 significantly reduced these levels, especially the intracellular levels. In addition, GV1001 restored the expression of survival-related proteins and reduced the expression of death associated ones in NSCs treated with H2O2. In conclusion, GV1001 has antioxidant and neuroprotective effects in NSCs following treatment with H2O2, which appear to be mediated by scavenging free radicals, increasing survival signals and decreasing death signals. (C) 2016 Elsevier B.V. All rights reserved.</P>

Genetic and phylogenetic characterizations of a novel genotype of highly pathogenic avian influenza (HPAI) H5N8 viruses in 2016/2017 in South Korea

Kim, Y.I.,Park, S.J.,Kwon, H.I.,Kim, E.H.,Si, Y.J.,Jeong, J.H.,Lee, I.W.,Nguyen, H.D.,Kwon, J.J.,Choi, W.S.,Song, M.S.,Kim, C.J.,Choi, Y.K. Elsevier Science 2017 INFECTION GENETICS AND EVOLUTION Vol.53 No.-

<P>During the outbreaks of highly pathogenic avian influenza (HPAI) H5N6 viruses in 2016 in South Korea, novel H5N8 viruses were also isolated from migratory birds. Phylogenetic analysis revealed that the HA gene of these H5N8 viruses belonged to clade 2.3.4.4, similarly to recent H5Nx viruses, and originated from A/Brk/Korea/Gochang1/14(H5N8), a minor lineage of H5N8 that appeared in 2014 and then disappeared. At least four reassortment events occurred with different subtypes (H5N8, H7N7, H3N8 and H10N7) and a chicken challenge study revealed that they were classified as HPAI viruses according to OIE criteria. (C) 2017 Elsevier B.V. All rights reserved.</P>

Genetic diversity and pathogenic potential of low pathogenic H7 avian influenza viruses isolated from wild migratory birds in Korea

Kim, Y.I.,Kim, S.W.,Si, Y.J.,Kwon, H.I.,Park, S.J.,Kim, E.H.,Kim, S.m.,Lee, I.W.,Song, M.S.,Choi, Y.K. Elsevier Science 2016 Infection, genetics and evolution Vol.45 No.-

To detect the circulation of H7 avian influenza viruses, we characterized H7 viruses found in migratory birds and live poultry markets of South Korea from 2005 to 2014. Phylogenic analysis revealed that while all viruses clustered into the Eurasian-lineage of H7 avian viruses, at least 12 distinct genotypes were represented. Most H7 viruses contained at least one gene segment from the highly-pathogenic A/Sck/Hong Kong/YU100/02(H5N1)-like avian virus, and they could be separated into at least two antigenic groups. Although we did not detect genetically identical strains, HI assay demonstrated close cross-reactivity of some isolates with the H7N9 viruses from China. Animal studies revealed that most of the genotypes could replicate in the lungs of mice and chickens without prior adaptation and some, particularly H7N4 and H7N7 subtypes, induced mortality in mice. These results reinforce growing pandemic concerns regarding recent H7 viruses and emphasize the importance of continued surveillance of avian influenza viruses in the wild.

Cross-protective efficacies of highly-pathogenic avian influenza H5N1 vaccines against a recent H5N8 virus

Park, S.J.,Si, Y.J.,Kim, J.,Song, M.S.,Kim, S.m.,Kim, E.H.,Kwon, H.i.,Kim, Y.I.,Lee, O.J.,Shin, O.S.,Kim, C.J.,Shin, E.C.,Choi, Y.K. Academic Press 2016 Virology Vol.498 No.-

<P>To investigate cross-protective vaccine efficacy of highly-pathogenic avian influenza H5N1 viruses against a recent HPAI H5N8 virus, we immunized C57BL/6 mice and ferrets with three alum-adjuvanted inactivated whole H5N1 vaccines developed through reverse-genetics (Rg): [Vietnam/1194/04xPR8 (clade 1), Korea/W149/06xPR8 (clade 2.2), and Korea/ES223N/03xPR8 (clade 2.5)]. Although relatively low cross-reactivities (10-40 HI titer) were observed against heterologous H5N8 virus, immunized animals were 100% protected from challenge with the 20 mLD(50) of H5N8 virus, with the exception of mice vaccinated with 3.5 mu g of Rg Vietnam/1194/04xPR8. Of note, the Rg Korea/ES223N/03xPR8 vaccine provided not only effective protection, but also markedly inhibited viral replication in the lungs and nasal swabs of vaccine recipients within five days of HPAI H5N8 virus challenge. Further, we demonstrated that antibody-dependent cell-mediated cytotoxicity (ADCC) of an antibody-coated target cell by cytotoxic effector cells also plays a role in the heterologous protection of H5N1 vaccines against H5N8 challenge. (C) 2016 Elsevier Inc. All rights reserved.</P>

Surveillance of avian influenza virus in wild bird fecal samples from South Korea, 2003-2008.

Kang, H M,Jeong, O M,Kim, M C,Kwon, J S,Paek, M R,Choi, J G,Lee, E K,Kim, Y J,Kwon, J H,Lee, Y J [Wildlife Disease Association] 2010 JOURNAL OF WILDLIFE DISEASES Vol.46 No.3

<P>We analyzed the results from nationwide surveillance of avian influenza (AI) from birds in South Korea's major wild bird habitats and the demilitarized zone of South Korea, 2003-2008. Of 28,214 fecal samples analyzed, 225 yielded influenza viruses, for a prevalence of 0.8%. Hemagglutinin (HA) subtypes H1-H12 and all nine neuraminidase (NA) subtypes were detected. The dominant HA subtypes were H6, H1, and H4, and the most common NA subtypes were N2, N1, and N6. Among the 38 HA/NA subtype combinations, the most common were H4N6, H6N1, and H5N2. Thirty-seven low-pathogenic AI (LPAI) viruses of the H5 and H7 subtype were detected. Among them, we identified bird species for 16 H5- and H7-positive fecal samples using a DNA bar-coding system instituted in 2007; all birds were identified as Anseriformes. The HA gene of the H5 wild bird isolates belonged to the Eurasian avian lineage, and could be clearly distinguished from the sublineage H5N1 highly pathogenic AI (HPAI) of the Eurasian and American avian lineages. Whereas H7 LPAI viruses did not group as a separate sublineage with H7 HPAI viruses, H7 isolates were closely related with the Eurasian avian lineage.</P>

Evaluation of the zoonotic potential of a novel reassortant H1N2 swine influenza virus with gene constellation derived from multiple viral sources

Lee, J.H.,Pascua, P.N.Q.,Decano, A.G.,Kim, S.M.,Park, S.J.,Kwon, H.I.,Kim, E.H.,Kim, Y.I.,Kim, H.,Kim, S.Y.,Song, M.S.,Jang, H.K.,Park, B.K.,Choi, Y.K. Elsevier Science 2015 INFECTION GENETICS AND EVOLUTION Vol.34 No.-

In 2011-2012, contemporary North American-like H3N2 swine influenza viruses (SIVs) possessing the 2009 pandemic H1N1 matrix gene (H3N2pM-like virus) were detected in domestic pigs of South Korea where H1N2 SIV strains are endemic. More recently, we isolated novel reassortant H1N2 SIVs bearing the Eurasian avian-like swine H1-like hemagglutinin and Korean swine H1N2-like neuraminidase in the internal gene backbone of the H3N2pM-like virus. In the present study, we clearly provide evidence on the genetic origins of the novel H1N2 SIVs virus through genetic and phylogenetic analyses. In vitro studies demonstrated that, in comparison with a pre-existing 2012 Korean H1N2 SIV [A/swine/Korea/CY03-1½012 (CY03-1½012)], the 2013 novel reassortant H1N2 isolate [A/swine/Korea/CY0423/2013 (CY0423-12/2013)] replicated more efficiently in differentiated primary human bronchial epithelial cells. The CY0423-12/2013 virus induced higher viral titers than the CY03-1½012 virus in the lungs and nasal turbinates of infected mice and nasal wash samples of ferrets. Moreover, the 2013 H1N2 reassortant, but not the intact 2012 H1N2 virus, was transmissible to naive contact ferrets via respiratory-droplets. Noting that the viral precursors have the ability to infect humans, our findings highlight the potential threat of a novel reassortant H1N2 SIV to public health and underscore the need to further strengthen influenza surveillance strategies worldwide, including swine populations.

Amplification of Porcine SRY Gene for Sex Determination

Choi, S.G.,Bae, M.S.,Lee, E.S.,Kim, S.O.,Kim, B.K.,Yang, J.H.,Jeon, C.E.,Kim, H.H.,Hwang, Y.J.,Lee, E.S.,Kim, D.Y. Asian Australasian Association of Animal Productio 2009 Animal Bioscience Vol.22 No.8

The separation of X and Y chromosome-bearing sperm is of use in many aspects of livestock maintenance. In this study, we sought to determine the difference in DNA content between X- and Y-bearing sperm, separate sperm into X- and Y-enriched pools, and assess the efficacy of sorting. Sperm collected from Duroc and miniature pigs were stained with 20.8 $\mu{M}$ Hoechst 33342 and analyzed using a high-speed cell sorter. Measurement of the fluorescence intensity of stained sperm nuclei revealed that the X-bearing sperm of Duroc and miniature pigs respectively contain 2.75% and 2.88% more DNA than Y-bearing sperm. In total, 50.18% of the sperm were assigned to the X-sorted sample and 49.82% was assigned to the Y-sorted sample for Duroc pigs. For miniature pigs, the Xsorted sample represented 50.19% of the population and the Y-sorted represented 49.81% of the population. Duplex PCR was used to evaluate accuracy of sorting. A fast and reliable method for porcine sexing was developed through amplification of the sex-determining region of the Y chromosome gene (SRY). Oligonucleotide primers were designed to amplify the conserved porcine SRY high motility group (HMG) box sequence motif. We found that the primer pair designed in this study was 1.46 times more specific than previously reported primers. Thus, this study shows that the present method can be applied in porcine breeding programs to facilitate manipulation of the sex ratio of offspring and to achieve precise sexing of porcine offspring by amplification of the HMG box of the SRY gene.