• Title/Summary/Keyword: M.R.T.

Search Result 2,807, Processing Time 0.023 seconds

Association of a Provisional New emm Type Opacity Factor-Negative Group A Streptococci Strain ST4529 with Septicemia

  • R.R. Rantty;M. Eshaghi;A.M. Ali;F. Jamal;K. Yusoff
    • Journal of Microbiology
    • /
    • v.39 no.3
    • /
    • pp.236-239
    • /
    • 2001
  • Group A Streptococcus strain ST4529 is a provisional new ems type which has been recently reported in Malaysia (Jomal, et al. 1999. Energ. Infect . Dis. 5,10-14). This strain was found to be opacity factor (OF) negative with a Tl phenotype. Usually, OF negative strains with T1 phenotypes are associated with acute rheumatic fever. However, strain ST4529 was isolated from the blood of a patient with septicemia. Comparison of the deduced amino acid sequence of the mature hypervariable N-terminus of ST4529 showed only 43% identity with that of M5, the closest matched OF negative strain with a T1 phenotype. Thus, ST4529 most probably encodes a new serospecifically unique M protein which is associated with septicemia rather than pharyngitis infections. The strains with these phenotypes are very important because their sequences should be considered for developing any anti-streptococcal vaccines.

  • PDF

Effects of Supplemental Feather Digests on the Growth of Broiler Chicks and Taurine Content in the Broiler Meat (우모 가수분해물 첨가가 육계의 증체 및 계육 내 타우린 함량에 미치는 영향)

  • 홍성진;남궁환;김우연;백인기
    • Korean Journal of Poultry Science
    • /
    • v.29 no.2
    • /
    • pp.141-148
    • /
    • 2002
  • Two experiments were conducted to investigate the effects of supplemental feather digests on the growth of broiler chicks and taurine content in the broiler meat. In experiment 1, a total of 40 broiler chickens(Ros $s_{R}$) were assigned to four dietary treatments: control(T1), regular feather meal(FM) diet(R-FM,T2), NaOH treated FM diet(NaOH-FM,T3), HNO) treated FM diet($HNO_{3}$ -FM, T4). In experiment 2, a total of 70 broiler chickens were assigned to seven dietary treatments: T1 to t4(same as those of Exp. 1), modified $HNO_{3}$ treated FM diet(M- $HNO_{3}$-FM, T5), hair meal diet(HM, T6) and 0.22% cystine supplemented diet(CYS, T7). Feather meals and hair meal were supplemented at the level of 5% in the diet. In experiment 1 and 2, weight gain of chicks frd with R-FM or NaOH-FM tended to be higher than control or $HNO_{3}$ -FM. In experiment 2, weight gain of chicks frd with CYS was the highest followed by R-FM, M-HN $O_3$-FM, NaOH-FM, control, HM and $HNO_{3}$ -FM. In experiment 1, taurine content in breast muscle of chicks fed NaOH-FM was sogmofocamtly higher(P<0.05) than control. In experiment 2, taurine content in breast muscle of chicks fed NaOH-FM and CYS tended to be higher than other groups. Taurine content in leg muscle was significantly different among treatments as NaOH-FM and R-FM being highest followed by M- $HNO_{3}$-FM, CYS, control, $HNO_{3}$ -FM and HM. Taurine content in the liver(Exp. 1 and 2) and heart(Exp. 2) were not significantly affected by the supplemental feather digests. These results indicated that 5% NaOH-FM in the diet was effective in increasing taurine content in breast and leg muscle of broiler chicks.s.

An Adaptive Signal Transmission/Reception Scheme for Spectral Efficiency Improvement of Multiple Antenna Systems in Cellular Environments (셀룰러 환경에서 다중 안테나 시스템의 전송 효율 증대를 위한 적응적 송수신 방안)

  • Jin, Gwy-Un;Kim, Seong-Min;Chang, Jae-Won;Sung, Won-Jin
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.33 no.6C
    • /
    • pp.429-437
    • /
    • 2008
  • Multiple-input multiple-output (MIMO) techniques can be used for the spectral efficiency enhancement of the cellular systems, which can be categorized into spatial multiplexing (SM) and spatial diversity schemes. MIMO systems suffer a severe performance degradation due to the intercell interference from the adjacent cells as the mobile terminal moves toward the cell boundary. Therefore for the spectral efficiency enhancement, an appropriate transmission scheme for the given channel environment and reception scheme which can mitigate the intercell interference are required. In this paper, we propose an adaptive signal transmission/reception scheme for the spectral efficiency improvement of $M_R{\times}M_T$ MIMO systems, present the decision criteria for the adaptive operation of the proposed scheme, and demonstrate the performance gain. The proposed scheme performs adaptive transmission using spatial multiplexing and spatial diversity, and adaptive reception using maximal ratio combining (MRC) and intercell spatial demultiplexing (ISD) when the spatial diversity transmission is used at the transmitter. Spatial multiplexing/demultiplexing is performed at the high signal-to-interference ratio (SIR) range, and the transmit diversity in conjunction with the adaptive reception uses either conventional MRC or ISD which can mitigate the $M_R-1$ interference signals, based on the mobile location. For the performance evaluation of the proposed adaptive scheme, the probability density function (pdf) of the effective SIR for the transmission/reception methods in consideration are derived for $M_R{\times}M_T$ MIMO systems. Using the results, the average effective SIR and spectral efficiency are presented and compared with simulation results.

Integration Process and Reliability for $SrBi_2$ $Ta_2O_9$-based Ferroelectric Memories

  • Yang, B.;Lee, S.S.;Kang, Y.M.;Noh, K.H.;Hong, S.K.;Oh, S.H.;Kang, E.Y.;Lee, S.W.;Kim, J.G.;Shu, C.W.;Seong, J.W.;Lee, C.G.;Kang, N.S.;Park, Y.J.
    • JSTS:Journal of Semiconductor Technology and Science
    • /
    • v.1 no.3
    • /
    • pp.141-157
    • /
    • 2001
  • Highly reliable packaged 64kbit ferroelectric memories with $0.8{\;}\mu\textrm{m}$ CMOS ensuring ten-year retention and imprint at 125^{\circ}C$ have been successfully developed. These superior reliabilities have resulted from steady integration schemes free from the degradation, due to layer stress and attacks of process impurities. The resent results of research and development for ferroelectric memories at Hynix Semiconductor Inc. are summarized in this invited paper.

  • PDF

Cellular Protective and Antioxidative Acivities of Parthenocissus tricuspidata Stem Extracts (담쟁이덩굴 줄기 추출물의 세포 보호 작용과 항산화 활성)

  • Jo, Na-Rae;Park, Min-A;Chae, Kyo-Young;Park, Su-Ah;Jeon, So-Ha;Ha, Ji-Hoon;Park, Soo-Nam
    • Journal of the Society of Cosmetic Scientists of Korea
    • /
    • v.38 no.3
    • /
    • pp.225-236
    • /
    • 2012
  • In this study, the cellular protective effects on HaCaT cells and human erythrocytes and antioxidative effects of P. tricuspidata stem extracts were investigated. The ethyl acetate ($50{\mu}g/mL$) and aglycone fraction ($25{\mu}g/mL$) of P. tricuspidata stem extracts doesn't show any characteristics of cytotoxicity. When HaCaT cells were treated with 10 mM $H_2O_2$ and $30{\mu}M$ rose bengal, the ethyl acetate ($6.25{\sim}50{\mu}g/mL$) and aglycone ($6.25{\sim}25{\mu}g/mL$) fraction protected the cells against the oxidative damage in a concentration dependent manner. The P. tricuspidata stem extracts showed more prominent cellular protective effect than (+)-${\alpha}$-tocopherol, known as lipid antioxidant at $10{\mu}g/mL$. The ethylacetate fraction of P. tricuspidata stem extracts ($18.5{\mu}g/mL$) showed more free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activity ($FSC5_{50}$). Reactive oxygen species (ROS) scavenging activity ($OSC_{50}$) of P. tricuspidata stem extracts on ROS generated in $Fe^{3+}$-EDTA/$H_2O_2$ system was investigated using the luminol-dependent chemiluminescence assay. The ethyl acetate ($1.72{\mu}g/mL$) and the aglycone fraction ($1.53{\mu}g/mL$) showed similar ROS scavenging activity of L-ascorbic acid ($1.50{\mu}g/mL$). These results indicate that extract/fractions of P. tricuspidata stem extracts can function as natural cytoprotective agents and antioxidants in biological systems, particularly skin exposed to UV radiation by protecting cellular membrane against ROS.

Analyses for hydraulic gradient and major flow direction of groundwater in the soil aquifer (토양층에서 지하수 수리경사와 주 흐름 방향 분석)

  • Kim, Tae-Yeong;Kang, Dong-Hwan;KIm, Sung-Soo;Kwon, Byung-Hyuk;Yu, Hun-Sun
    • Proceedings of the Korea Water Resources Association Conference
    • /
    • 2009.05a
    • /
    • pp.1955-1959
    • /
    • 2009
  • 본 연구에서는 토양층에서 지하수 수리경사와 주 흐름 방향을 산정하여 변동특성을 분석하고, 그 원인에 대해 고찰하였다. 연구부지는 부경대학교 환경연구동 앞 잔디밭이며, 2008년 10월 18일 ${\sim}$ 11월 1일의 기간 중 12일(10월 21, 28일은 관측 못함) 동안 24회 관측되었다. 관측된 지하수공은 9개공이며, 4 m ${\times}$ 4 m의 정방형으로 설계되었다. 지하수위에 의한 수리경사와 주 흐름 방향의 산정은 총 9가지 형태의 평면으로 가정하여 산정하였다. 수리경사와 주 흐름 방향을 산정하기 위한 평면은 모두 9가지 형태로 가정하였다. 첫 번째는 9개공 모두를 이용한 정방형 평면(TW), 두 번째는 6개공을 이용한 4가지 경우의 삼각형 평면(T1, T2, T3 및 T4), 세 번째는 6개공을 이용한 4가지 경우의 직사각형 평면(R1, R2, R3 및 R4)으로 가정하여 각각의 평면에서 수리경사와 주 흐름 방향을 산정하였다. 이상에서 가정된 9가지 평면에서 산정된 평균 수리경사는 0.0094(R2) ${\sim}$ 0.0123(T2)의 범위로 나타났으며, 9개공 모두를 이용한 평면(TW)에서의 평균 수리경사는 0.0109로 산정되었다. 관측기간 동안 T1과 T3 평면의 평균 주 흐름 방향은 각각 -84.9818과 -86.2487로서, 다른 7개 평면의 평균 주 흐름 방향이 79.7045(T4) ${\sim}$ 85.8405(TW)의 범위로 나타난 것과는 반대의 흐름 방향을 보였다. 이러한 결과는, 본 연구에 적용된 수리경사와 주 흐름 방향의 산정기법(Devlin, 2003)이 삼각형 형태의 평면에는 부적합할 수 있음을 보여주는 것이다. 관측기간 중 10월 12일에 내린 소량의 강우(12 mm)에 의한 수리경사와 주 흐름 방향의 변동은 크게 나타나지 않았다. 본 연구에서는 정방형, 삼각형 및 직사각형의 평면 토양층에서 지하수의 수리경사와 주 흐름 방향을 산정하여 전체 및 국부적인 부지에서의 차이를 파악하고, 평면의 형태에 따른 수리경사와 주 흐름 방향의 차이 또한 확인할 수 있었다.

  • PDF

Pathogen-Imprinted Polymer Film Integrated probe/Ti3C2Tx MXenes Electrochemical Sensor for Highly Sensitive Determination of Listeria Monocytogenes

  • Xiaohua, Jiang;Zhiwen, Lv;Wenjie, Ding;Ying, Zhang;Feng, Lin
    • Journal of Electrochemical Science and Technology
    • /
    • v.13 no.4
    • /
    • pp.431-437
    • /
    • 2022
  • As one of the most hazardous and deadliest pathogens, Listeria monocytogenes (LM) posed various serious diseases to the human being, thus designing effective strategy for its detection is of great significance. In this work, by preparing Ti3C2Tx MXenes nanoribbon (Ti3C2TxR) as carrier and selecting thionine (Th) acted simultaneously as signal probe and functional monomer, a LM pathogen-imprinted polymers (PIP) integrated probe electrochemical sensor was design to monitor LM for the first time, that was carried out through the electropolymerization of Th on the Ti3C2TxR/GCE surface in the existence of LM. Upon eluting the templates from the LM imprinted cavities, the fabricated PIP/Ti3C2TxR/GCE sensor can rebound LM cells effectively. By recording the peak current of Th as the response signal, it can be weakened when LM cell was re-bound to the LM imprinted cavity on PIP/Ti3C2TxR/GCE, and the absolute values of peak current change increase with the increasement of LM concentrations. After optimizing three key parameters, a considerable low analytical limit (2 CFU mL-1) and wide linearity (10-108 CFU mL-1) for LM were achieved. In addition, the experiments demonstrated that the PIP/Ti3C2TxR sensor offers satisfactory selectivity, reproducibility and stability.

SOME EXAMPLES OF QUASI-ARMENDARIZ RINGS

  • Hashemi, Ebrahim
    • Bulletin of the Korean Mathematical Society
    • /
    • v.44 no.3
    • /
    • pp.407-414
    • /
    • 2007
  • In [12], McCoy proved that if R is a commutative ring, then whenever g(x) is a zero-divisor in R[x], there exists a nonzero c $\in$ R such that cg(x) = 0. In this paper, first we extend this result to monoid rings. Then for a monoid M, we give some examples of M-quasi-Armendariz rings which are a generalization of quasi-Armendariz rings. Every reduced ring is M-quasi-Armendariz for any unique product monoid M and any strictly totally ordered monoid $(M,\;{\leq})$. Also $T_4(R)$ is M-quasi-Armendariz when R is reduced and M-Armendariz.