Antibiotic susceptibility and resistance of Streptococcus iniae and Streptococcus parauberis isolated from olive flounder (Paralichthys olivaceus)

Park, Y.K.,Nho, S.W.,Shin, G.W.,Park, S.B.,Jang, H.B.,Cha, I.S.,Ha, M.A.,Kim, Y.R.,Dalvi, R.S.,Kang, B.J.,Jung, T.S. Elsevier Scientific Pub. Co 2009 Veterinary microbiology Vol.136 No.1

The rates of antibiotic susceptibility and resistance were investigated in Streptococcus iniae and Streptococcus parauberis isolates obtained from diseased olive flounders (Paralichthys olivaceus) collected from fish farms in Jeju Island, Korea. Isolates of S. iniae (n=65) were susceptible to cefotaxime, erythromycin, ofloxacin, penicillin, tetracycline and vancomycin, as demonstrated by the minimum inhibitory concentration (MIC) test. Isolates of S. parauberis (n=86) were highly resistant to erythromycin (58% of the 86 isolates tested) and tetracycline (63% of the 86 isolates tested). Fifty-four isolates of tetracycline-resistant S. parauberis contained the tet(M/O/S) genes, of which 39 and 12 isolates contained the tet(M) and tet(S) genes, respectively, whereas 3 isolates contained both the tet(M) and tet(S) genes. Among the erythromycin-resistant isolates of S. parauberis (n=50) only 14 contained the erm(B) gene. These results suggest that the tet(S) and erm(B) genes of S. parauberis are involved in the acquisition of high-level resistance to erythromycin and tetracycline. Our findings reveal a high rate of antibiotic resistance among strains of S. parauberis and emphasize the need to develop an appropriate vaccine to reduce the use of antibiotics.

In vitro and in vivo antifungal activities of decursin and decursinol angelate isolated from Angelica gigas against Magnaporthe oryzae, the causal agent of rice blast

Yoon, M.Y.,Kim, Y.S.,Ryu, S.Y.,Choi, G.J.,Choi, Y.H.,Jang, K.S.,Cha, B.,Han, S.S.,Kim, J.C. Academic Press 2011 Pesticide biochemistry and physiology Vol.101 No.2

Blast is considered the most important fungal disease of rice due to its wide distribution and destructiveness under favorable conditions. Development of new effective and environmentally benign agents against the causal pathogen, Magnaporthe oryzae, is of great interest. In the course of a search for natural antifungal compounds in medicinal plants, we found that the methanol extract of Angelica gigas roots showed a potent control efficacy against rice blast caused by M. oryzae. We isolated antifungal coumarins from the extract, and they were identified as decursin and decursinol angelate. Antifungal activities of these compounds, along with kasugamycin, were tested on M. oryzae in vivo and in vitro. In an in vivo assay, the three compounds effectively suppressed the development of rice blast at concentrations more than 100μg/mL. Coumarins showed relatively weak inhibitory effect on fungal mycelial growth when compared to kasugamycin. However, they strongly inhibited M. oryzae spore germination, which was not observed in kasugamycin treatments. This is the first report demonstrating that decursinol angelate can provide control against rice blast and that the two coumarins inhibit M. oryzae spore germination. In addition, the wettable powder formulation of the crude extract of A. gigas prohibited the development of blast symptoms on rice plants more effectively than liquid concentrate formulation of kasugamin, a commercial fungicide. Based on our study, we propose that coumarin compounds as well as the A. gigas root crude extract can be used as natural, benign fungicides for controlling rice blast.

Inflammatory lipid sphingosine-1-phosphate upregulates C-reactive protein via C/EBPβ and potentiates breast cancer progression

Kim, E-S,Cha, Y,Ham, M,Jung, J,Kim, S G,Hwang, S,Kleemann, R,Moon, A Macmillan Publishers Limited 2014 Oncogene Vol.33 No.27

A crucial role of the inflammatory lipid sphingosine-1-phosphate (S1P) in breast cancer aggressiveness has been reported. Recent clinical studies have suggested that C-reactive protein (CRP) has a role in breast cancer development. However, limited information is available on the molecular basis for the expression of CRP and its functional significance in breast cell invasion. The present study aimed to elucidate the molecular link between S1P and CRP during the invasive process of breast epithelial cells. This is the first report showing that transcription of CRP was markedly activated by S1P in breast cells. Our data suggest that not only S1P treatment but also the endogenously produced S1P may upregulate CRP in breast carcinoma cells. Transcription factors CCAAT/enhancer-binding protein beta and c-fos were required for S1P-induced CRP expression. Coupling of S1P<SUB>3</SUB> to heterotrimeric G<SUB>αq</SUB> triggered the expression of CRP, utilizing signaling pathways involving reactive oxygen species (ROS), Ca<SUP>2+</SUP> and extracellular signal-related kinases (ERKs). S1P-induced CRP expression was crucial for the transcriptional activation of matrix metalloproteinase-9 through ERKs, ROS and c-fos, leading to breast cell invasion. Using a xenograft mice tumor model, we demonstrated that S1P induced CRP expression both in vitro and in vivo. Taken together, our findings have revealed a molecular basis for S1P-induced transcriptional activation of CRP and its functional significance in the acquisition of the invasive phenotype of human breast epithelial cells under inflammatory conditions. Our findings may provide useful information on the identification of useful therapeutic targets for inflammatory breast cancer.

주메모리 실시간 저장시스템을 위한 개방적 트랜잭션 스케쥴러 라이브러리의 설계 및 구현

권오성(O. S. Kwon),송세혁(S. H. Song),차상균(S. K. Cha),채미옥(M. O. Chae) 한국정보과학회 1996 한국정보과학회 학술발표논문집 Vol.23 No.1A

실시간 데이타베이스 연산들의 정확성은 수행되는 논리적 연산뿐만 아니라 실시간 트랜잭션들의 결과가 도축되는 시간에도 좌우된다. 실시간 DBMS가 가능한 많은 트랜잭션들을 그들의 시간 제약 조건들을 위배하지 않고서 완수하는 것을 보장하기 위해서는 실시간 DBMS의 스케쥴링 전략은 실시간 트랜잭션들과 데이타베이스와 관련된 시간 제약 조건들에 관한 정보들을 이용해야만한다. 이 논문은 M²RTSS(Main-Memory Real-Time Storage System)의 트랜잭션들에 대한 몇 가지의 스케쥴링 알고리듬을 제안한다. 이러한 알고리듬들을 구현한 스케쥴러들은 시스템의 재사용성과 확장가능성을 향상시키기 위해 객체지향 방식에 의해 설계되었다. M²RTSS를 이용하는 프로그래머는 어떤 스케쥴링 알고리듬도 선택할 수 있을 뿐만 아니라 시스템의 다른 부분에 영향을 끼치지 않고서 자신의 응용 분야에 적절한 새로운 알고리듬을 구현할 수 도 있다. 우리는 이 연구가 진행됨에 따라 M²RTSS가 다양한 응용 분야를 지원하는 일반적인 실시간 DBMS로 발전되기를 희망한다.

Synthesis and characterization of macrocyclic nickel(II) complexes with α-methylbenzyl groups as chiral pendants

Han, J.H.,Cha, M.J.,Kim, B.G.,Kim, S.K.,Min, K.S. Elsevier 2008 Inorganic chemistry communications Vol.11 No.7

Novel nickel(II) hexaaza macrocyclic complexes, [Ni(L<SUP>R,R</SUP>)](ClO<SUB>4</SUB>)<SUB>2</SUB> (1) and [Ni(L<SUP>S,S</SUP>)](ClO<SUB>4</SUB>)<SUB>2</SUB> (2), containing chiral pendant groups have been synthesized by an efficient one-pot template condensation and characterized (L<SUP>R,R/S,S</SUP>=1,8-di((R/S)-α-methylbenzyl)-1,3,6,8,10,13-hexaazacyclotetradecane). The crystal structures of 1 and 2 were determined by single-crystal X-ray analysis. Each complex has a square-planar coordination environment for the nickel(II) ion, and is either an R or an S enantiomorph depending on the pendant groups. The circular dichroism spectrum of 1 showed a negative, positive and negative peak at 345, 440, and 492nm, respectively, and that of 2 exhibited an enantiomeric pattern.

MoO3 / bismuth molybdate 혼합 2상 촉매의 구조에 따른 프로필렌 선택산화반응 특성

차태병,최명재,박대원,정종식 ( T . B . Cha,M . J . Choi,D . W . Park,J . S . Chung ) 한국공업화학회 1992 공업화학 Vol.3 No.1

프로필렌을 선택산화시켜 아크로레인을 제조하는 반응을 Bi-molybdate 촉매상에서 고정층 반응기를 사용하여 연구하였다. α-Bi_2Mo_3O_12 위에 MoO_3를 담지시킨 M/BM-series 촉매는 함침법으로 제조되었고, 역으로 BM/M-series 촉매는 MoO_3 위에 α-Bi_2Mo_3O_12을 침전시켜 제조하였다. 또한 촉매의 특성분석을 위하여 질소흡착과 XRD, SEM을 이용하였다. M/BM-series 촉매에서는 MoO_3가 작은 입자로 분산되고 α-Bi_2Mo_3O_12의 결정구조는 MoO_3상이 추가되어도 그 형상이 변하지 않는 채로 유지되었으나, BM/M-series 촉매의 표면형상 및 전체 구조는 촉매제조 중에 생기는 침전물인 Bi(OH)_3가 소성 도중 MoO_3와 반응하여 α-Bi_2Mo_3O_12을 형성하는 관계로 그 조성에 따라 매우 불규칙적으로 변화하였다. 반응실험 결과, 두 종류의 촉매 모두에서 excess MoO_3가 포함되었을 때 활성이 크게 증가하였는데, 이는 선별산화반응이 주로 α-Bi_2Mo_3O_12에서 일어나고 MoO_3는 α-Bi_2Mo_3O_12에 산소 공급을 원활히 하여 활성을 증가시키기 때문으로 판명되었다. 또한 이러한 활성 증가는 α-Bi_2Mo_3O_12와 기계적 혼합물 (mechanical mixture)에서도 관찰되었다. M/BM-series catalysts, MoO_3 supported on α-Bi_2Mo_3O_12 were prepared by impregnation method. BM/M-series catalysts, α-Bi_2Mo_3O_12 supported on MoO_3 were also prepared by coprecipitation. Structure and catalytic properties of the two phase catalysts were studied by means of using nitrogen adsorption, X-ray diffraction, and scanning electron microscopy. The reaction test for the selective oxidation of propylene to acrolein over Bi-molybdate catalysts was studied using a fixed-bed reactor system. In M/BM -series catalysts, MoO_3 was dispersed on α-Bi_2Mo_3O_12, and the crystal structure of α-Bi_2Mo_3O_12 remains unchanged by the presence of excess MoO_3. However the surface morphology and bulk structure of BM/M-series catalysts were altered probably because the precipitated Bi(OH)_3 reacted with MoO_3 during the calcination to form α-Bi_2Mo_3O_12 phase. The results of propylene oxidation on both series catalysts showed that the reaction took place over the surface of α-Bi_2Mo_3O_12 particle and the role of excess MoO_3 was to supply oxygen to α-Bi_2Mo_3O_12. These increasing effects on activity were also observed in the mechanical mixtures of α-Bi_2Mo_3O_12 and MoO_3.

A SUPER-JUPITER MICROLENS PLANET CHARACTERIZED BY HIGH-CADENCE KMTNET MICROLENSING SURVEY OBSERVATIONS OF OGLE-2015-BLG-0954

신인구,Y.-H. Ryu,A. Udalski,M. Albrow,S.-M. Cha,J.-Y. Choi,S.-J. Chung,C. Han,K.-H. Hwang,Y. K. Jung,D.-J. Kim,S.-L. Kim,C.-U. Lee,Y. Lee,B.-G. Park,H. Park,R. W. Pogge,J. C. Yee,P. Pietrukowicz,P. Mroz 한국천문학회 2016 Journal of The Korean Astronomical Society Vol.49 No.3

We report the characterization of a massive $(m_p=3.9\pm 1.4 M_{\rm jup})$ microlensing planet (OGLE-2015-BLG-0954Lb) orbiting an M dwarf host ($M=0.33\,\pm 0.12 M_\odot$) at a distance toward the Galactic bulge of $0.6^{+0.4}_{-0.2}\,$kpc, which is extremely nearby by microlensing standards. The planet-host projected separation is $a_\perp \sim 1.2\,\au$. The characterization was made possible by the wide-field ($4\,\rm deg^2$) high cadence ($\Gamma = 6\,\rm hr^{-1}$) monitoring of the Korea Microlensing Telescope Network (KMTNet), which had two of its three telescopes in commissioning operations at the time of the planetary anomaly. The source crossing time $t_*=16\,$min is among the shortest ever published. The high-cadence, wide-field observations that are the hallmark of KMTNet are the only way to routinely capture such short crossings. High-cadence resolution of short caustic crossings will preferentially lead to mass and distance measurements for the lens. This is because the short crossing time typically implies a nearby lens, which enables the measurement of additional effects (bright lens and/or microlens parallax). When combined with the measured crossing time, these effects can yield planet/host masses and distance.

OGLE-2016-BLG-0263Lb: Microlensing Detection of a Very Low-mass Binary Companion through a Repeating Event Channel

Han, C.,Udalski, A.,Gould, A.,Bond, I. A.,Albrow, M. D.,Chung, S.-J.,Jung, Y. K.,Ryu, Y.-H.,Shin, I.-G.,Yee, J. C.,Zhu, W.,Cha, S.-M.,Kim, S.-L.,Kim, D.-J.,Lee, C.-U.,Lee, Y.,Park, B.-G.,Skowron, J.,M American Astronomical Society 2017 The Astronomical journal Vol.154 No.4

<P>We report the discovery of a planet-mass companion to the microlens OGLE-2016-BLG-0263L. Unlike most low-mass companions that were detected through perturbations to the smooth and symmetric light curves produced by the primary, the companion was discovered through the channel of a repeating event, in which the companion itself produced its own single-mass light curve after the event produced by the primary had ended. Thanks to the continuous coverage of the second peak by high-cadence surveys, the possibility of the repeating nature due to source binarity is excluded with a 96% confidence level. The mass of the companion estimated by a Bayesian analysis is Mp = 4.1(-2.5)(+6.5) M-j. The projected primary-companion separation is a(perpendicular to) = 6.5(-1.9)(+1.3) au. The ratio of the separation to the snow-line distance of a(perpendicular to/)a(s1) similar to 15.4 corresponds to the region beyond Neptune, the outermost planet of the solar system. We discuss the importance of high-cadence surveys in expanding the range of microlensing detections of low-mass companions and future space-based microlensing surveys.</P>

OGLE-2016-BLG-1469L: Microlensing Binary Composed of Brown Dwarfs

Han, C.,Udalski, A.,Sumi, T.,Gould, A.,Albrow, M. D.,Chung, S.-J.,Jung, Y. K.,Ryu, Y.-H.,Shin, I.-G.,Yee, J. C.,Zhu, W.,Cha, S.-M.,Kim, S.-L.,Kim, D.-J.,Lee, C.-U.,Lee, Y.,Park, B.-G.,Soszyń,ski, American Astronomical Society 2017 The Astrophysical journal Vol.843 No.1

<P>We report the discovery of a binary composed of two brown dwarfs, based on the analysis of the microlensing event OGLE-2016-BLG-1469. Thanks to the detection of both finite-source and microlens-parallax effects, we are able to measure both the masses M-1 similar to 0.05M(circle dot) and. M-2 similar to 0.01M(circle dot), and the. distance D-L similar to 4.5 kpc, as well as the projected separation a(perpendicular to) similar to 0.33 au. This is the third brown-dwarf binary detected using the microlensing method, demonstrating the usefulness of microlensing in detecting field brown-dwarf binaries with separations of less than 1 au.</P>

Synthesis and characterization of ampelopsin glucosides using dextransucrase from Leuconostoc mesenteroides B-1299CB4: Glucosylation enhancing physicochemical properties

Woo, H.J.,Kang, H.K.,Nguyen, T.T.H.,Kim, G.E.,Kim, Y.M.,Park, J.S.,Kim, D.,Cha, J.,Moon, Y.H.,Nam, S.H.,Xia, Y.m.,Kimura, A.,Kim, D. IPC Science and Technology Press ; Elsevier Scienc 2012 Enzyme and microbial technology Vol.51 No.6

Novel ampelopsin glucosides (AMPLS-Gs) were enzymatically synthesized and purified using a Sephadex LH-20 column. Each structure of the purified AMPLS-Gs was determined by nuclear magnetic resonance, and the ionic product of AMPLS-G1 was observed at m/z 505 (C<SUB>21</SUB>H<SUB>22</SUB>O<SUB>13</SUB>.Na)<SUP>+</SUP> using matrix-assisted laser desorption ionization time-of-flight mass spectrometry. AMPLS-G1 was identified as ampelopsin-4'-O-α-d-glucopyranoside. The optimum condition for AMPLS-G1, determined using response surface methodology, was 70mM ampelopsin, 150mM sucrose, and 1U/mL dextransucrase, which resulted in an AMPLS-G1 yield of 34g/L. The purified AMPLS-G1 displayed 89-fold increased water solubility and 14.5-fold browning resistance compared to those of AMPLS and competitive inhibition against tyrosinase with a K<SUB>i</SUB> value of 40.16μM. This value was smaller than that of AMPLS (K<SUB>i</SUB>=62.56μM) and much smaller than that of β-arbutin (K<SUB>i</SUB>=514.84μM), a commercial active ingredient of whitening cosmetics. These results indicate the potential of AMPLS and AMPLS-G1 as superior ingredients for functional cosmetics.