Prevalence and characterization of Salmonella in pigs from conventional and organic farms and first report of S. serovar 1,4,[5],12:i:- from Korea

Tamang, M.D.,Gurung, M.,Nam, H.M.,Moon, D.C.,Kim, S.R.,Jang, G.C.,Jung, D.Y.,Jung, S.C.,Park, Y.H.,Lim, S.K. Elsevier Scientific Pub. Co 2015 Veterinary microbiology Vol.178 No.1

<P>This study compared the prevalence of Salmonella spp. and their antimicrobial susceptibilities in pigs from conventional and organic farms during 2012-2013 in Korea and characterized them by molecular methods. Altogether, 100 nontyphoid Salmonella were isolated: 47 from 1324 pigs (3.5%) from conventional farms and 53 from 641 pigs (8.3%) from organic farms. The most frequent serovar was Typhimurium (49%) followed by Panama (24%), 1,4,[5],12:i:- (5%), and Virchow (5%). Overall, the isolates were most often resistant to tetracycline (75%) followed by ampicillin (66%), streptomycin (57%), and gentamicin (44%). The prevalence of antimicrobial resistance, multi-drug resistance phenotype, and resistance to tetracycline, ampicillin, and gentamicin were significantly higher in swine Salmonella from conventional farms than those from organic farms. The most common resistance pattern was ampicillin-gentamicin-tetracycline (n = 16). All eight ceftiofur-resistant Salmonella identified produced CTX-M-15. Overall, decreased susceptibility to ciprofloxacin was observed in 39 isolates. Among them, a single isolate was positive for qnrS1 gene. An insertion sequence ISEcp1 was detected upstream of bla(CTX-M) gene in all isolates. The spread of bla(CTX-M-15) gene was attributed to combination of clonal expansion and horizontal dissemination mediated by IncHI2 plasmid. Multilocus variable number of tandem repeats analysis demonstrated clonal dissemination of S. Typhimurium and S. 1,4,[5],12:i:- strains in pigs. To our knowledge, this is the first report of bla(CTX-M-15) gene in S. Virchow from pigs and qnrS1 gene in S. Rissen from animals. This study also reports the first occurrence of Salmonella serovar 1,4,[5],12:i:- from Korea and CTX-M-15 producing Salmonella from pigs in Korea. (C) 2015 Elsevier B.V. All rights reserved.</P>

2주간 간헐적인 저압,저산소 트레이닝이 남녀 지구성선수의 체성분, 유산소성 운동능력 및 혈중 산소포화도에 미치는 영향

남상석 ( S. S. Nam ),이만균 ( M. G. Lee ),선우섭 ( Oo S. Sun ) 한국운동생리학회(구 한국운동과학회) 2011 운동과학 Vol.20 No.3

남상석, 이만균, 선우섭. 2주간 간헐적인 저압·저산소 트레이닝이 남녀 지구성선수의 체성분, 유산소성 운동능력 및 혈중 산소포화도에 미치는 영향. 운동과학, 제20권 제3호. 283-296. 2011. 본 연구에서는 2주간 간헐적(주당 3회)인 저압·저산소 트레이닝이 지구성 운동선수의 체성분, 유산소성 운동능력 및 혈중 산소포화도에 미치는 효과가 성별에 따라 다르게 나타나는지 여부를 규명하고자 하였다. 남자축구선수(n=8명)와 여자 필드하키선수(n=9명)를 대상으로 2,000 m 상당의 저압·저산소 환경에서 2주간, 격일로 총 6회의 트레이닝(자전거타기 30분과 트레드밀 달리기 30분, 총 60분)을 실시하였다. 트레이닝 전후에 해수면 수준과 5,000 m 상당고도에서 각각 사전·사후검사를 실시하였다. 주요 연구결과는 다음과 같다. 1. 체성분의 변화에는 체중을 제외하고 성차가 나타나지 않았다. 2. 해수면 수준에서의 유산소성 운동능력의 변화에는 유의한 성차가 나타나지 않았다. 5,000 m 상당고도에서는 남자선수의 경우 추정된 VO2max를 제외한 모든 변인에서 트레이닝 후 유의하게 증가된 반면, 여자선수의 경우 유의한 변화가 나타나지 않았다. 즉, 5,000 m 상당고도에서의 유산소성 운동능력 변화에는 유의한 성차가 나타났으며, 이는 남녀 간의 근육량의 차이에 일부 기인하는 것으로 확인되었다. 3. 혈중 산소포화도의 변화에는 성차가 나타나지 않았다. 이상의 결과를 종합해 볼 때, 지구성 종목의 남녀 선수를 대상으로 2주간 간헐적인 저압·저산소 트레이닝을 실시한 경우 5,000 m 상당의 높은 고지대 환경에서의 유산소성 운동능력 개선이 여자에 비해 남자에게서 더 크게 나타난 것으로 결론지을 수 있다. This study was designed to investigate the effects of gender on changes of body composition, aerobic exercise capacity, and %SpO2, shown by two weeks of intermittent hypobaric hypoxia training on in endurance athletes. Male soccer players (n=8) and female hockey players (n=9) underwent the exercise training (cycling 30 min & running 30 min, total 60 min) in 2,000 m-simulated hypobaric hypoxia environment every other day (six times) for 2 weeks. Pre-test and post-test were performed in sea level and 5,000 m-simulated hypobaric hypoxia before and after the training, and the data were compared by gender and test. Main results of the study were as follows: 1. No significant gender difference was shown in changes of body composition, except body weight. 2. No significant gender difference was shown in changes of aerobic exercise capacity in sea level. There were significant improvements of aerobic capacity in 5,000 m condition in male athletes, whereas there were no significant changes of the variables in female athletes, indicating that significant gender difference was found in the changes of aerobic capacity in 5,000 m condition. 3. No significant gender difference was shown in changes of %SpO2. It was concluded that the improvement of aerobic exercise capacity in 5,000 m condition shown by short-term intermittent hypobaric hypoxia training was greater in male athletes than in female athletes.

S6K1 Phosphorylation of H2B Mediates EZH2 Trimethylation of H3: A Determinant of Early Adipogenesis

Yi, S.,Um, S.,Lee, J.,Yoo, J.,Bang, S.,Park, E.,Lee, M.,Nam, K.,Jeon, Y.,Park, J.,You, J.,Lee, S.J.,Bae, G.U.,Rhie, J.,Kozma, Sara C.,Thomas, G.,Han, J.W. Cell Press 2016 Molecular Cell Vol.62 No.3

S6K1 has been implicated in a number of key metabolic responses, which contribute to obesity. Critical among these is the control of a transcriptional program required for the commitment of mesenchymal stem cells to the adipocytic lineage. However, in contrast to its role in the cytosol, the functions and targets of nuclear S6K1 are unknown. Here, we show that adipogenic stimuli trigger nuclear translocation of S6K1, leading to H2BS36 phosphorylation and recruitment of EZH2 to H3, which mediates H3K27 trimethylation. This blocks Wnt gene expression, inducing the upregulation of PPARγ and Cebpa and driving increased adipogenesis. Consistent with this finding, white adipose tissue from S6K1-deficient mice exhibits no detectable H2BS36 phosphorylation or H3K27 trimethylation, whereas both responses are highly elevated in obese humans or in mice fed a high-fat diet. These findings define an S6K1-dependent mechanism in early adipogenesis, contributing to the promotion of obesity.

Hairy and Enhancer of Split 6 (Hes6) Deficiency in Mouse Impairs Neuroblast Differentiation in Dentate Gyrus Without Affecting Cell Proliferation and Integration into Mature Neurons

Nam, S. M.,Kim, Y. N.,Kim, J. W.,Kyeong, D. S.,Lee, S. H.,Son, Y.,Shin, J. H.,Kim, J.,Yi, S. S.,Yoon, Y. S. Springer Science + Business Media 2016 Cellular and molecular neurobiology Vol.36 No.1

<P>Hes6 is a member of the hairy-enhancer of split homolog (Hes) family of transcription factors and interacts with other Hes family genes. During development, Hes genes are expressed in neural stem cells and progenitor cells. However, the role of Hes6 in adult hippocampal neurogenesis remains unclear. We therefore investigated the effects of Hes6 on adult hippocampal neurogenesis, by comparing Hes6 knockout and wild-type mice. To this end, we immunostained for markers of neural stem cells and progenitor cells (nestin), proliferating cells (Ki67), post-mitotic neuroblasts and immature neurons (doublecortin, DCX), mature neuronal cells (NeuN), and astrocyte (S100 beta). We also injected 5-bromo-2'-deoxyuridine (BrdU) to trace the fate of mitotic cells. Nestin- and Ki67-positive proliferating cells did now show any significant differences between wild and knockout groups. Hes6 knockout negatively affects neuroblast differentiation based on DCX immunohistochemistry. On the contrary, the ratio of the BrdU and NeuN double-positive cells did not show any significance, even though it was slightly higher in the knockout group. These results suggest that Hes6 is involved in the regulation of neuroblast differentiation during adult neurogenesis, but does not influence integration into mature neurons.</P>

Gelatin-based sponge with Ag nanoparticles prepared by solution plasma: Fabrication, characteristics, and their bactericidal effect

Kim, S.C.,Kim, S.M.,Yoon, G.J.,Nam, S.W.,Lee, S.Y.,Kim, J.W. Elsevier 2014 Current Applied Physics Vol.14 No.suppl2

A solution plasma process was established for fabrication of gelatin-based sponge incorporated with Ag nanoparticles (AgNPs) in this study. Without using any chemical reducing agent, colloidal AgNPs were formed in gelatin medium via the reduction reaction of Ag precursors (AgNO<SUB>3</SUB>) and the hydrogen radicals generated during discharge. The gelatin/AgNPs sponges fabricated by lyophilization had a 3D scaffold structure of micropores with diameters of about 20 μm. TEM analysis showed that the spherical AgNPs in the thin layer of gelatin were evenly well dispersed and had mean particle sizes of about 10-15 nm. The gelatin/AgNP solutions and sponges prepared in this study exhibited excellent bactericidal activity against two well-known bacteria, Escherichia coli and Staphylococcus aureus. All of them inhibited growth of E. coli more efficiently than that of S. aureus. Minimal inhibition concentration of gelatin/AgNP formed with 3% gelatin and 5 mM AgNO<SUB>3</SUB> was <20 and 40 μg/ml for E. coli and S. aureus, respectively. The sponge of 3% gelatin and 5 mM AgNO<SUB>3</SUB> discharged for 740 s showed the strongest bactericidal activity toward both bacteria.

Tissue Culture and Production of Secondary Metabolites of Domestic Medicinal Herbs-Ⅱ. Production of Secondary Metabolites of Pinellia ternata and Melandryum firmum

Yang, M.S.,Choi, S.U.,Nam, S.H.,Kim, L.S. Gyeongsang National University 1991 Plant molecular biology and biotechnology research Vol.1991 No.

Pinellia ternata Thunb. and Melandryum firmum Rohbach used as medicinal herbs were cultured and analyzed secondary metabolites. The saponin contents were the highest level between 25 and 30 culture days. The addition of phenylalanine and methionine in medium effected the ephedrine production in P. ternata. The effective precursors on saponin production were sitosterol and mevalonate in P. ternata and M. firmum. Protocom-like body derived from P. ternata was produced to the most amount of saponin and ephedrine.

Defect reduction of SiN_x embedded m-plane GaN grown by hydride vapor phase epitaxy

Woo, S.,Kim, M.,So, B.,Yoo, G.,Jang, J.,Lee, K.,Nam, O. North-Holland Pub. Co 2014 Journal of crystal growth Vol.407 No.-

Nonpolar (10-10) m-plane GaN has been grown on m-plane sapphire substrates by hydride vapor phase epitaxy (HVPE). We studied the defect reduction of m-GaN with embedded SiN<SUB>x</SUB> interlayers deposited by ex-situ metal organic chemical vapor deposition (MOCVD). The full-width at half-maximum values of the X-ray rocking curves for m-GaN with embedded SiN<SUB>x</SUB> along [11-20]<SUB>GaN</SUB> and [0001]<SUB>GaN</SUB> were reduced to 528 and 1427arcs, respectively, as compared with the respective values of 947 and 3170arcs, of m-GaN without SiN<SUB>x</SUB>. Cross-section transmission electron microscopy revealed that the basal stacking fault density was decreased by approximately one order to 5x10<SUP>4</SUP>cm<SUP>-1</SUP> due to the defect blocking of the embedded SiN<SUB>x</SUB>. As a result, the near band edge emission intensities of the room-temperature and low-temperature photoluminescence showed approximately two-fold and four-fold improvement, respectively.

Antimicrobial Susceptibility of Coagulase-Negative Staphylococci Isolated from Bovine Mastitis Between 2003 and 2008 in Korea

( J. M. Kim ),( S. K. Lim ),( J. S. Moon ),( Nam H. M. ),( H. M. Kang ),( G. C. Jang ),( S. H. Wee ),( Y. S. Joo ),( S. C. Jung ) 한국미생물 · 생명공학회 2010 Journal of microbiology and biotechnology Vol.20 No.10

A total of 1,444 coagulase-negative staphylococci (CNS) isolates from bovine mastitic milk samples collected during 2003-2008 in Korea were identified to the species level. Of 14 species identified, S. simulans, S. haemolyticus, and S. sciuri accounted for over 60% of the isolates. All the CNS isolates were tested for susceptibility to eight antimicrobials commonly used in dairy cattle. With a few exceptions, similar resistance patterns were observed among the CNS species: penicillin and ampicillin showed the lowest activity, whereas amikacin, cephalothin, and gentamicin were highly effective. About 39% (557/1,444) of the CNS isolates were pan-susceptible, whereas 12% (175/1,444) showed resistance to four or more antimicrobials tested.

High-resolution electrohydrodynamic inkjet printing of stretchable metal oxide semiconductor transistors with high performance

Kim, S.-Y.,Kim, K.,Hwang, Y. H.,Park, J.,Jang, J.,Nam, Y.,Kang, Y.,Kim, M.,Park, H. J.,Lee, Z.,Choi, J.,Kim, Y.,Jeong, S.,Bae, B.-S.,Park, J.-U. The Royal Society of Chemistry 2016 Nanoscale Vol.8 No.39

<P>As demands for high pixel densities and wearable forms of displays increase, high-resolution printing technologies to achieve high performance transistors beyond current amorphous silicon levels and to allow low-temperature solution processability for plastic substrates have been explored as key processes in emerging flexible electronics. This study describes electrohydrodynamic inkjet (e-jet) technology for direct printing of oxide semiconductor thin film transistors (TFTs) with high resolution (minimum line width: 2 mu m) and superb performance, including high mobility (similar to 230 cm(2) V-1 s(-1)). Logic operations of the amplifier circuits composed of these e-jet-printed metal oxide semiconductor (MOS) TFTs demonstrate their high performance. Printed In2O TFTs with e-jet printing-assisted high-resolution S/D electrodes were prepared, and the direct printing of passivation layers on these channels enhanced their gate-bias stabilities significantly. Moreover, low process temperatures (<250 degrees C) enable the use of thin plastic substrates; highly flexible and stretchable TFT arrays have been demonstrated, suggesting promise for next-generation printed electronics.</P>

Optical subthreshold current method for extracting the interface states in MOS systems

Kim, M.S.,Nam, I.C.,Kim, H.T.,Shin, H.T.,Kim, T.E.,Park, H.S.,Kim, K.S.,Kim, K.H.,Choi, J.B.,Min, K.S.,Kim, D.J.,Kang, D.W.,Kim, D.M. IEEE 2004 IEEE electron device letters Vol.25 No.2

Optical subthreshold current method (OSCM) is proposed for characterizing the interface states in MOS systems using the current-voltage characteristics under a photonic excitation. An optical source with a subbandgap (E<SUB>ph</SUB>>E<SUB>g</SUB>) photonic energy (E<SUB>ph</SUB>=0.943 eV, P<SUB>opt</SUB>=+5 dBm), which is less than the silicon bandgap (E<SUB>g</SUB>=1.12;eV), is employed for the optical subthreshold current characterization of interface states in the photoresponsive energy band. We applied the OSCM method under a subbandgap photonic excitation to MOS systems with a poly-Si gate and verified a U-shaped distribution of interface trap density D<SUB>it</SUB>=10<SUP>10</SUP>∼10<SUP>12</SUP> eV<SUP>-1</SUP>cm<SUP>-2</SUP> for n- and p-type MOSFETs with W/L=30 μm/1.2 μm.