Multilocus Sequence Typing and Virulence Factors Analysis of Escherichia coli O157 Strains in China

Xiao W. Ji,Ya L. Liao,Ye F. Zhu,Hai G. Wang,Ling Gu,Jiang Gu,Chen Dong,Hong L. Ding,Xu H. Mao,Feng C. Zhu,Quan M. Zou 한국미생물학회 2010 The journal of microbiology Vol.48 No.6

Escherichia coli O157:H7, an important food-borne pathogen, has become a major public health concern worldwide. The aim of this study was to investigate the molecular epidemiologic feature of E. coli O157:H7strains in China. 105 E. coli O157:H7 isolates were collected from various hosts and places over 9 years. A multilocus sequence typing scheme (MLST) was applied for bacteria genotyping and polymerase chain reaction (PCR) was used for virulence factor identification. Seven new MLST sequence types (STs), namely ST836, ST837, ST838, ST839, ST840, ST841, and ST842 were identified, which grouped into two lineages. Phylogenetic analysis suggested that the most two frequent STs in China, ST837 and ST836, may be the derivatives of E. coli O157:H7 Sakai or E. coli O157:H7 EDL933. Geographical diversity and host variety of E. coli O157:H7 were observed in China. In addition, the different distribution of tccp was detected. The data presented herein provide new insights into the molecular epidemiologic feature of E. coli O157:H7, and aid in the investigation of the transmission regularity and evolutionary mechanism of E. coli O157:H7.

Electric Probe Measurements at Edge Region During H‐Mode Discharges in KSTAR

Bak, J.G.,Oh, Y.S.,Kim, H.S.,Hahn, S.H.,Yoon, S.W.,Jeon, Y.M.,Xiao, W.W.,Ko, W.H.,Kim, W.C.,Kwak, J.G.,Woo, H.J.,Chung, K.S.,the KSTAR project team, WILEY‐VCH Verlag 2013 Contributions to plasma physics Vol.53 No.1

<P><B>Abstract</B></P><P>Electrical probe measurements are carried out at the scrape‐off‐layer (SOL) and divertor regions in order to investigate the characteristics of edge plasmas during H‐mode discharges in the Korea Superconducting Tokamak Advanced Research (KSTAR) device. Radial profiles of plasma parameters such as electron temperature T<SUB><I>e</I></SUB>, plasma density n<SUB><I>e</I></SUB>, and parallel flow velocity v<I><SUB>‖</SUB></I> are measured by using a fast reciprocating Langmuir probe assembly (FRLPA) at the SOL region. From the FRLPA measurements, it is found that the decay length of temperature λ<I><SUB>Te</SUB></I> and that of density λ<I><SUB>ne</SUB></I> are 2 <I>∼</I> 4 cm and 1 <I>∼</I> 3 cm, respectively. The magnitude of v<I><SUB>‖</SUB></I> near the last closed flux surface (LCFS) is 4 <I>∼</I> 15 km/s. The radial flux due to edge turbulence at the SOL region is investigated by using spectra analysis on electrostatic fluctuation levels such as ion saturation current Ĩ<I><SUB>is</SUB></I> and floating potential <TEX>$ \tilde{\rm V}_f$</TEX> obtained from the FRLPA measurement. The value of the flux is estimated as <I>∼</I> 10<SUP>20</SUP> particle m<SUP>−2</SUP> s <SUP>−1</SUP> near the LCFS. The poloidal distribution of the ion saturation current density j<I><SUB>is</SUB></I> is measured by fixed edge Langmuir probe array (ELPA) at the divertor region, and it is found that the positions of strike points from the ELPA measurement agree well with those reconstructed from the EFIT result using magnetic diagnostic data. From the spectrum analysis on the ELPA measurements at the divertor region during edge localized modes (ELMs) control in the H‐mode discharges, it is observed that the magnitude of <TEX>$ \tilde{\rm j}_{is}$</TEX>(<I>ω</I>) near strike point decreases when the ELMs are suppressed or mitigated (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)</P>

Taxonomy of fungal complex causing red-skin root of Panax ginseng in China

Xiao H. Lu,Xi M. Zhang,Xiao L. Jiao,Jianjun J. Hao,Xue S. Zhang,Yi Luo,Wei W. Gao 고려인삼학회 2020 Journal of Ginseng Research Vol.44 No.3

Background: Red-skin root of Asian ginseng (Panax ginseng) significantly reduces the quality and limits theproduction of ginseng in China. The disease has long been thought to be a noninfectious physiologicaldisease, except one report that proved itwas an infectious disease. However, the causal agents have not beensuccessfully determined. In the present study, we were to reveal the pathogens that cause red-skin disease. Methods: Ginseng roots with red-skin root symptoms were collected from commercial fields in NortheastChina. Fungi were isolated from the lesion and identified based on morphological characters alongwith multilocus sequence analyses on internal transcription spacer, b-tubulin (tub2), histone H3 (his3),and translation elongation factor 1a (tef-1a). Pathogens were confirmed by inoculating the isolates inginseng roots. Results: A total of 230 isolates were obtained from 209 disease samples. These isolates were classifiedinto 12 species, including Dactylonectria sp., D. hordeicola, Fusarium acuminatum, F. avenaceum, F. solani,F. torulosum, Ilyonectria mors-panacis, I. robusta, Rhexocercosporidium panacis, and three novel speciesI. changbaiensis, I. communis, and I. qitaiheensis. Among them, I. communis, I. robusta, and F. solani had thehighest isolation frequencies, being 36.1%, 20.9%, and 23.9%, respectively. All these species isolated werepathogenic to ginseng roots and caused red-skin root disease under appropriate condition. Conclusion: Fungal complex is the causal agent of red-skin root in P. ginseng.

Taxonomy of fungal complex causing red-skin root of Panax ginseng in China

Lu, Xiao H.,Zhang, Xi M.,Jiao, Xiao L.,Hao, Jianjun J.,Zhang, Xue S.,Luo, Yi,Gao, Wei W. The Korean Society of Ginseng 2020 Journal of Ginseng Research Vol.44 No.3

Background: Red-skin root of Asian ginseng (Panax ginseng) significantly reduces the quality and limits the production of ginseng in China. The disease has long been thought to be a noninfectious physiological disease, except one report that proved it was an infectious disease. However, the causal agents have not been successfully determined. In the present study, we were to reveal the pathogens that cause red-skin disease. Methods: Ginseng roots with red-skin root symptoms were collected from commercial fields in Northeast China. Fungi were isolated from the lesion and identified based on morphological characters along with multilocus sequence analyses on internal transcription spacer, β-tubulin (tub2), histone H3 (his3), and translation elongation factor 1α (tef-1α). Pathogens were confirmed by inoculating the isolates in ginseng roots. Results: A total of 230 isolates were obtained from 209 disease samples. These isolates were classified into 12 species, including Dactylonectria sp., D. hordeicola, Fusarium acuminatum, F. avenaceum, F. solani, F. torulosum, Ilyonectria mors-panacis, I. robusta, Rhexocercosporidium panacis, and three novel species I. changbaiensis, I. communis, and I. qitaiheensis. Among them, I. communis, I. robusta, and F. solani had the highest isolation frequencies, being 36.1%, 20.9%, and 23.9%, respectively. All these species isolated were pathogenic to ginseng roots and caused red-skin root disease under appropriate condition. Conclusion: Fungal complex is the causal agent of red-skin root in P. ginseng.

A Timetable of the Early Development Stage of Silkies Embryo

Li, B.C.,Chen, G.H.,Qin, J.,Wang, K.H.,Xiao, X.J.,Xie, K.Z.,Wu, X.S. Asian Australasian Association of Animal Productio 2003 Animal Bioscience Vol.16 No.6

The early embryos are obtained in different time after the former egg had been laid, and the aim of the present study was to observe the development law of chicken early embryo.The embryo development has been divided into the two periods according to morphology of blastodisc. Cleavage period, from 5.5 h (0 h uterine age) to 15.5 h (10-10.5 h uterine age) after the former egg had laid, formation blastodisc of 6-7 layers cell. Later blastocyst period, from 17.5 h (12-12.5 h uterine age) to area pellucida formation after the former egg had been laid. The first division took place at 5 h (0 h uterine age), morular at 11.5 h (6-6.5 h uterine age), and blastocyst at 15.5 h (10-10.5 h uterine age) after the former egg had been laid.

Event-triggered _{H ∞} filtering of discrete-time switched linear systems

Xiao, Xiaoqing,Park, Ju H.,Zhou, Lei Elsevier 2018 ISA transactions Vol.77 No.-

<P><B>Abstract</B></P> <P>In this paper, the event-triggered <SUB> H ∞ </SUB> filtering problem for discrete-time switched linear systems is addressed. The filter and the system are connected via a communication network, and the transmitted information of system output and switching signal is determined by an event-triggered transmission scheme, which contains system mode dependent parameters. Consequently, the asynchronous switching between the filter and the system occurs, and the filtering error system is modeled as a switched system with augmented switching signal by using the merging switching signal technique. Then, by the multiple Lyapunov function method, a new sufficient condition is obtained such that the filtering error system is exponentially asymptotically stable and satisfies the weighted <SUB> H ∞ </SUB> performance. Finally, the design method for the filter and event-triggered parameters is proposed by solving a set of linear matrix inequalities. Numerical simulations illustrate the effectiveness of the proposed approach.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The event-triggered <SUB> H ∞ </SUB> filtering problem for discrete-time switched linear systems is addressed. </LI> <LI> A mode dependent event-triggered transmission scheme is proposed. </LI> <LI> A new result for the exponential stability and weighted <SUB> H ∞ </SUB> performance of the filtering error system. </LI> </UL> </P>

Microstructure and joint properties of ultrasonically brazed Al alloy joints using a Zn-Al hypereutectic filler metal

Xiao, Y.,Ji, H.,Li, M.,Kim, J.,Kim, H. Scientific and Technical Press ; Elsevier Science 2013 Materials & design Vol.47 No.-

The ultrasound-assisted brazing of 1060 Al alloy using a Zn-14Al hypereutectic filler metal was investigated at different temperatures. The effects of brazing temperature on the bonding ratio, shear strength and microstructure of the joints were studied. Cavities and discontinuous cracks were found in the joint ultrasonically brazed at 410<SUP>o</SUP>C, and the joint showed a low bonding ratio and poor shear strength. Excellent bonding ratios and high shear strength were obtained in the joints ultrasonically brazed at 440<SUP>o</SUP>C and 470<SUP>o</SUP>C. The primary α-Al phase showed a refined spherical shape in the joint ultrasonically brazed at 440<SUP>o</SUP>C, but showed a coarse dendritic structure in the joint ultrasonically brazed at 470<SUP>o</SUP>C and that brazed at 440<SUP>o</SUP>C without ultrasonic vibration. The refined spherical microstructure shown in the joint ultrasonically brazed at 440<SUP>o</SUP>C was attributed to cavitation-aided grain refinement effects.

Computational simulations of microscale shock-vortex interaction using a mixed discontinuous Galerkin method

Xiao, H.,Myong, R.S. Pergamon Press ; Elsevier Science Ltd 2014 Computers & fluids Vol.105 No.-

This study extensively investigates the physics of microscale shock-vortex interaction of argon gas by solving conservation laws with non-Newtonian constitutive relations. In order to solve the conservation laws and associated implicit type second-order constitutive equations of viscous stress and heat flux numerically, a mixed discontinuous Galerkin (DG) formulation is developed. Three major characteristics are found in the microscale shock-vortex interaction in thermal nonequilibrium: the absence of quadrupolar acoustic wave structure, which is the major feature in macroscale near-equilibrium; the increase in the dissipation rate during the strong interaction; and the decrease in enstrophy during the weak interaction. Moreover, we show that the strong shock-vortex interaction in high shock or vortex Mach numbers can cause an increase in enstrophy. We also find the viscous effect to be dominant in the net vorticity generation. Among shock and vortex parameters, the shock Mach number, vortex Mach number and vortex size turn out to play a critical role in the deformation of the vortex and the strength of interaction, which in turn govern the evolution of vorticity due to the viscous effects, the change in the dissipation rate and the increase or decrease in enstrophy during the interaction.

The rediscovery of Phytophthora polygoni Saw

(Xiao Bo Zheng),(H . H . Ho) 한국균학회 2001 Proceedings of the Fifth Korea-China Joint Symposi Vol.- No.-

THE DEVELOPMENT OF A LOW NOISE 230 GHZ SIS RECEIVER IN NAGOYA UNIVERSITY

XIAO K. C.,OGAWA H.,FUKUI Y.,SUZUKI H. The Korean Astronomical Society 1996 Journal of The Korean Astronomical Society Vol.29 No.suppl1

A 230 GHz SIS tunnel junction receiver has been being developed for radio astronomy in Nagoya University. In this heterodyne receiver, we use a $\~$1/3 reduced hight rectangular waveguide SIS mixer with two tuning elements as front end. The mixer block with SIS junction was cooled to 4K with a closed cycle He-gas refrigerator. So far, a double sideband receiver noise temperature lower than l00K in 222-237 GHz is obtained. The receiver exhibits a best DSB noise temperature of 69K at 236 GHz as well as 228 GHz.