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.

TEM investigation of hydrogen-implanted and annealed single-crystal SrTiO3

G.K.H. Pang,C.W. Tai,Y. Wang,W.L. Liu,Z.T. Song,S.L. Feng,H.L.W. Chan,C.L. Choy 한국물리학회 2006 Current Applied Physics Vol.6 No.3

In this study, the structural properties of single-crystal SrTiO3 implanted with H+ have been investigated by transmission electronmicrocopy (TEM). The investigation was carried out on an as-implanted sample and samples after annealing at 500.C and 700 .Cfrom the implanted energy similar to the process in the case of silicon. The as-implanted sample shows large out-of-plane strain alsosimilar to the report in silicon. The microcavities are lled with amorphous material as the result of complicated interaction of the defectsduring the annealing.

Effects of Immune Stress on Performance Parameters, Intestinal Enzyme Activity and mRNA Expression of Intestinal Transporters in Broiler Chickens

Feng, Y.,Yang, X.J.,Wang, Y.B.,Li, W.L.,Liu, Y.,Yin, R.Q.,Yao, J.H. Asian Australasian Association of Animal Productio 2012 Animal Bioscience Vol.25 No.5

Immune stress is the loss of immune homeostasis caused by external forces. The purpose of this experiment was to investigate the effects of immune stress on the growth performance, small intestinal enzymes and peristalsis rate, and mRNA expression of nutrient transporters in broiler chickens. Four hundred and thirty-two 1-d-old broilers (Cobb500) were randomly assigned to four groups for treatment; each group included nine cages with 12 birds per cage. Group 1 = no vaccine (NV); Group 2 = conventional vaccine (CV); group 3 = lipopolysaccharide (LPS)+conventional vaccine (LPS); group 4 = cyclophosphamide (CYP)+conventional vaccine (CYP). The results demonstrated that immune stress by LPS and CYP reduced body weight gain (BWG), feed intake (FI), small intestine peristalsis rate and sIgA content in small intestinal digesta (p<0.05). However, the feed conversion ratio (FCR) remained unchanged during the feeding period. LPS and CYP increased intestinal enzyme activity, relative expression of SGLT-1, CaBP-D28k and L-FABP mRNAs (p<0.05). LPS and CYP injection had a negative effect on the growth performance of healthy broiler chickens. The present study demonstrated that NV and CV could improve growth performance while enzyme activity in small intestine and relative expression of nutrient transporter mRNA of NV and CV were decreased in the conditions of a controlled rational feeding environment. It is generally recommended that broilers only need to be vaccinated for the diseases to which they might be exposed.

FATIGUE ASSESSMENT OF REAR AXLE UNDER SERVICE LOADING HISTORIES CONSIDERING THE STRENGTHENING AND DAMAGING EFFECTS OF LOADS BELOW FATIGUE LIMIT

L. H. ZHAO,S. L. ZHENG,J. Z. FENG,H. F. ZHOU,Y. F. XING 한국자동차공학회 2014 International journal of automotive technology Vol.15 No.5

Accurately predicting the fatigue life is the basis for the reliability and lightweight design of automobile parts. However, the predicted lives under service loadings on the basis of the S-N curve from constant amplitude loads from existingmethods often seems conservative compared with real lives, because of ignoring the strengthening effect of loads belowfatigue limit. In this paper, a fatigue damage model, which is modification of Miner's Rule, was established for the fatigueassessment under service loadings by means of taking into account the strengthening and damaging effects of loads belowfatigue limit. Then this model and conventional Miner's Rule are applied to the estimate the fatigue life of a torsion beam rearaxle using the loading history recorded on proving ground. Finally, verification tests are performed on MTS road loadsimulator test bed. Results of predicted lives and fatigue tests demonstrate that the accuracy of the predicted life could begreatly improved by taking into account the strengthening and damaging effect of loads below fatigue limit.

NANOSIZED HYDROXYAPATITE/COLLAGEN COMPOSITE

Feng, Feng, Q,L,Cui, Cui, F.Z,Wang, Wang, R.Z,Du, Du, C,Li, Li, H.D 한국재료학회 1995 Fabrication and Characterization of Advanced Mater Vol.1 No.2

This paper reported the synthesis of a nano-Hydroxyapatite(HAp)/collagen biocomposite and its biological performances. A thoroughly mixed slurry of type I collagen in supersaturated HAp solution was obtained. HAp was then controlled to precipitate on collagen by adjusting the solution properly. SEM, XRD and TEM analysis reveals that HAp in the composite was nanometer sized and uniformly dispersed oncollagen matrix. In vitro biocompatibility of this new biomaterial was evaluated in terms of its biodegradation and bioactivity. The mice macrophage and osteoblast were used for the study, and the behavior of the cells in contact with the composite was investigated by means of SEM. The observations showed that the composite can be degraded through extracellular resorption process mediated by macrophage, and they can also be well-contact with osteoblast cells, in vitro.

Nanostructured HfC-SiC composites prepared by high-energy ball-milling and reactive spark plasma sintering

Feng, L.,Lee, S.H.,Wang, H.L.,Lee, H.S. Elsevier Science Publishers 2016 Journal of the European Ceramic Society Vol.36 No.1

A novel route combining the reactive spark plasma sintering (R-SPS) and HfSi<SUB>2</SUB>-C powders was proposed for fabricating dense and nano-structured HfC-SiC composites. Ultra-fine and homogeneously distributed HfC (310nm) and SiC (210nm) grains were obtained after sintering at 1750<SUP>o</SUP>C, which were attributed to the molecular-level homogeneity of Si and Hf in HfSi<SUB>2</SUB>, the high-energy ball-milling of raw powders and low sintering temperature by R-SPS. The fracture toughness of the composites was improved up to 3MPam<SUP>½</SUP> because of the homogeneous distribution of HfC and SiC grains and consequent enhancement of crack deflection.

Electrospun Sn-doped LiTi2(PO4)3/C nanofibers for ultra-fast charging and discharging

Liu, L.,Song, T.,Han, H.,Park, H.,Xiang, J.,Liu, Z.,Feng, Y.,Paik, U. Royal Society of Chemistry 2015 Journal of Materials Chemistry A Vol.3 No.19

<P>Sn-doped LiTi2(PO4)(3)/C composite nanofibers are synthesized by a facile electrospinning process. The unique one dimensional nanostructure combined with a uniform electrically conductive carbon matrix allows high-rate transportation of lithium ions and electrons. Besides, Sn-doping could further decrease the electrochemical resistance. Sn-doped LiTi2(PO4)(3)/C composite nanofibers exhibit excellent electrochemical performance, especially ultra-fast charging/discharge capability. At a charging rate of about 600 C (64 A g(-1), 6 s), 66.2% capacity (68.9 mA h g(-1)) could be obtained when matched with a Li metal counter electrode. They also exhibit excellent electrochemical properties as an anode material for aqueous rechargeable lithium batteries. Sn-doped LiTi2(PO4)(3)/C composite nanofibers are promising electrode materials for both nonaqueous and aqueous lithium ion batteries.</P>

Effects of Fabric Surface Energy on Human Thermophysiological Responses during Exercise and Recovery

Zhou, L.Y.,Li, Y.,Chung, J.,Tokura, H.,Gohel, M.D.I.,Kwok, Y.L.,Feng, X.W. The Korean Fiber Society 2007 Fibers and polymers Vol.8 No.3

The present paper reports a study on influences of fabric surface energy of cotton and polyester garments on clothing microclimates and human thermophysiological responses during intermittent exercise and recovery. Eight healthy males wearing the garments prepared performed exercises and rest according to the following protocol: rest for 30 min, run on treadmill for total 60 min of three sessions with different intensity and duration, and then sit quietly for 30 min for recovery, all at $30^{\circ}C$ and relative humidity of 30 %, while the microclimate humidity ($H_{mc}$) and temperature ($T_{mc}$), the clothing outside surface humidity ($H_{co}$) and temperature ($T_{co}$), the skin temperatures and ear canal temperature ($T_{ear_canal})$ were measured. The garments are made of: (a) hydrophilic and hydrophobic cotton knitted fabrics, and (b) hydrophilic and hydrophobic polyester knitted fabrics. During and after exercise, for cotton, hydrophilic garment resulted in significant lower ${\Delta}H_{mc}$, ${\Delta}H_{co}$, ${\Delta}T_{mc}$, during recovery, higher ${\Delta}{\bar{T}}_{sk}$, lower ${\Delta}T_{ear_canal}$ and ${\Delta}T_{forehead}$. For polyester, hydrophilic garment resulted in significantly lower ${\Delta}H_{co}$, ${\Delta}T_{co}$, higher ${\Delta}T_{forehead}$, during E1, E2 and recovery session but lower during E3. In summary, surface energy of cotton garments had significant influences on human thermophysiological responses during exercise and recovery, and hydrophilic cotton garment was better than hydrophobic one to reduce heat stress. Surface energy of polyester garments had influences of lower significance, and hydrophilic garment appeared better than hydrophobic garment.

Gene Microarray Analysis for Porcine Adipose Tissue: Comparison of Gene Expression between Chinese Xiang Pig and Large White

Guo, W.,Wang, S.H.,Cao, H.J.,Xu, K.,Zhang, J.,Du, Z.L.,Lu, W.,Feng, J.D.,Li, N.,Wu, C.H.,Zhang, L. Asian Australasian Association of Animal Productio 2008 Animal Bioscience Vol.21 No.1

We created a cDNA microarray representing approximately 3,500 pig genes for functional genomic studies. The array elements were selected from 6,494 cDNA clones identified in a large-scale expressed sequence tag (EST) project. These cDNA clones came from normalized and subtracted porcine adipose tissue cDNA libraries. Sequence similarity searches of the 3,426 ESTs represented on the array using BLASTN identified 2,790 (81.4%) as putative human orthologs, with the remainder consisting of "novel" genes or highly divergent orthologs. We used the gene microarray to profile transcripts expressed by adipose tissue of fatty Chinese Xiang pig (XP) and muscley Large White (LW). Microarray analysis of RNA extracted from adipose tissue of fatty XP and muscley LW identified 81 genes that were differently expressed two fold or more. Transcriptional differences of four of these genes, adipocyte fatty acid binding protein (aP2), stearyl-CoA desaturase (SCD), sterol regulatory element binding transcription factor 1 (SREBF1) and lipoprotein lipase (LPL) were confirmed using SYBR Green quantitative RT-PCR technology. Our results showed that high expression of SCD and SREBF1 may be one of the reasons that larger fat deposits are observed in the XP. In addition, our findings also illustrate the potential power of microarrays for understanding the molecular mechanisms of porcine development, disease resistance, nutrition, fertility and production traits.

Improvement of lower hybrid current drive systems for high-power and long-pulse operation on EAST

Wang M.,Liu L.,Zhao L.M.,Li M.H.,Ma W.D.,Hu H.C.,Wu Z.G.,Feng J.Q.,Yang Y.,Zhu L.,Chen M.,Zhou T.A.,Jia H.,Zhang J.,Cao L.,Zhang L.,Liang R.R.,Ding B.J.,Zhang X.J.,Shan J.F.,Liu F.K.,Ekedahl A.,Gonich 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.11

Aiming at high-power and long-pulse operation up to 1000 s, some improvements have been made for both 2.45 GHz and 4.6 GHz lower hybrid (LH) systems during the recent 5 years. At first, the guard limiters of the LH antennas with graphite tiles were upgraded to tungsten, the most promising material for plasma facing components in nuclear fusion devices. These new guard limiters can operate at a peak power density of 12.9 MW/m2 . Strong hot spots were usually observed on the old graphite limiters when 4.6 GHz system operated with power >2.0 MW [B. N. Wan et al., Nucl. Fusion 57 (2017) 102019], leading to a reduction of the maximum power capability. With the new limiters, 4.6 GHz LH system, the main current drive (CD) and electron heating tool for EAST, can be operated with power >2.5 MW routinely. Long-pulse operation up to 100 s with 4.6 GHz LH power of 2.4 MW was achieved in 2021 and the maximal temperature on the guard limiters measured by an infrared (IR) camera was about 540 C, much below the permissible value of tungsten material (~1200 C). A discharge with a duration of 1056 s was achieved and the 4.6 GHz LH energy injected into the plasma was up to 1.05 GJ. Secondly, the fully-activemultijunction (FAM) launcher of 2.45 GHz system was upgraded to a passive-active-multijunction (PAM), for which the density of optimum coupling was relatively low (below the cut-off value). Good coupling with reflection coefficient ~3% has been achieved with plasma-antenna distance up to 11 cm for the new PAM. Finally, in order to eliminate the effect of ion cyclotron range of frequencies (ICRF) wave on 4.6 GHz LH wave coupling, the location of the ICRF launcher was changed to a port that is located 157.5 toroidally from the 4.6 GHz LH system and is not magnetically connected