• Title/Summary/Keyword: Key Technology

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Ion-Imprinted Polymers Modified Sensor for Electrochemical Detection of Cu2+

  • An, Zhuolin;Liu, Weifeng;Liang, Qi;Yan, Guang;Qin, Lei;Chen, Lin;Wang, Meiling;Yang, Yongzhen;Liu, Xuguang
    • Nano
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    • v.13 no.12
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    • pp.1850140.1-1850140.9
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    • 2018
  • An electrochemical sensor ($Cu^{2+}$-IIPs/GCE) was developed for detection of $Cu^{2+}$ in water. $Cu^{2+}$-IIPs/GCE was prepared by dispersing $Cu^{2+}$ imprinted polymers ($Cu^{2+}$-IIPs) on a preprocessed glassy carbon electrode. $Cu^{2+}$-IIPs were synthesized on the surface of modified carbon spheres by ion imprinting technology. The electrochemical performance of $Cu^{2+}$-IIPs/GCE was evaluated by differential pulse voltammetry method. The response of $Cu^{2+}$-IIPs/GCE to $Cu^{2+}$ was linear in $1.0{\times}10^{-5}mol/L$ to $1.0{\times}10^{-3}mol/L$. The detection limit was $5.99{\times}10^{-6}mol/L$ (S=N = 3). The current response value of $Cu^{2+}$-IIPs/GCE was 2.14 times that of the nonimprinted electrode. These results suggest that $Cu^{2+}$-IIPs/GCE can detect the concentration of $Cu^{2+}$ in water, providing a new way for heavy metal ions adsorption and testing.

New Evidence of Alleles (V199I and G52S) at the PRKAG3 (RN) Locus Affecting Pork Meat Quality

  • Chen, J.F.;Dai, L.H.;Peng, J.;Li, J.L.;Zheng, R.;Zuo, B.;Li, F.E.;Liu, M.;Yue, K.;Lei, M.G.;Xiong, Y.Z.;Deng, C.Y.;Jiang, S.W.
    • Asian-Australasian Journal of Animal Sciences
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    • v.21 no.4
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    • pp.471-477
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    • 2008
  • The porcine PRKAG3 (RN) gene encodes the regulatory gamma subunit of adenosine monophosphate-activated protein kinase (AMPK), which is a good candidate gene affecting meat quality. In this study, the effects of two missense mutations A595G (Ile199Val) and G154A (Gly52Ser) in porcine PRKAG3 gene on meat quality traits were studied in M. Longissimus dorsi (LD), M. Semispinalis capitis (SC) and M. Biceps femoris (BF) from different populations of 326 pigs. The PRKAG3 alleles 199I, 199IV, 52S and 52G were identified with PCR-RFLPs and all genotypes - 199I/199I, 199I/199V, 199V/199V, 52S/52S, 52S/52G and 52G/52G - were found. The frequency of V allele was larger than that of I allele in all populations. I allele frequency was zero in Chinese Meishan pigs (population D) especially. G allele frequency was larger than that of S allele in all populations except Large White (population A). Both variations at the PRKAG3 locus significantly affected these meat quality traits. The pork meat quality has not previously been established in Meishan or crosses thereof. The results suggested that generally pH of LD, SC and BF was higher in Meishan pigs than that in other populations. Moreover, Meishan pigs showed higher water-holding capacity and intramuscular fat (IMF), lower water content and water loss percentage compared to other populations in terms of the two variations. The results present here supply new evidence that alleles V199I and G52S at the PRKAG3 locus affect pork meat quality and provide useful information on pork production.

Numerical and experimental study of cone-headed projectile entering water vertically based on MMALE method

  • Cao, Miaomiao;Shao, Zhiyu;Wu, Siyu;Dong, Chaochao;Yang, Xiaotian
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.13 no.1
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    • pp.877-888
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    • 2021
  • The water entry behaviors of projectiles with different cone-headed angles were studied numerically, experimentally and theoretically, mainly focusing on the hydrodynamic impact in the initial stage. Based on MMALE algorithm, it was proposed a formula of impact deceleration, which relied on the initial entry velocity and cone-headed angle. Meanwhile, in order to verify the validity of the simulation model, experiments using accelerometer and high-speed camera were carried out, and their results were in a good agreement with simulation results. Also, theoretical calculation results of cavity diameter were compared with experiments and simulation results. It was observed that the simulation method had a good reliability, which would make forecast on impact deceleration in an engineering project.

An Efficient Key Management Scheme in Tactical Ad-Hoc Network (전술 Ad-hoc 네트워크에서의 효율적인 키 관리 기법)

  • Kim, Eun-Ho;Lee, Soo-Jin
    • Journal of the Korea Institute of Military Science and Technology
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    • v.12 no.3
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    • pp.317-324
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    • 2009
  • Tactical Information Communication Network(TICN) uses both a wireless and wired network. To support mobility in battlefield environments, the application of Ad-hoc networking technology to its wireless communication has been examined. However, Ad-hoc network is faced to many security threats due to its intrinsic characteristics. Therefore, to apply the Ad-hoc networking technology to battlefield environments and TICN, an intensive study on security countermeasure must go side by side with the development of enabling technology. In this paper, we suggest an efficient key management scheme for TICN of which the Ad-hoc networking technology is applied.

Expression of E. coli Phosphofructokinase Gene in an Autotrophic Bacterium Acidithiobacillus thiooxidans

  • Tian, Ke-Li;Lin, Jian-Qun;Liu, Xiang-Mei;Liu, Ying;Zhang, Chang-Kai;Yan, Wang-Ming
    • Journal of Microbiology and Biotechnology
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    • v.14 no.1
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    • pp.56-61
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    • 2004
  • A plasmid pSDK-l containing the Escherichia coli phosphofructokinase-l gene (pfkA) was constructed, and transferred into extremely acidophilic Acidithiobacillus thiooxidans Tt-7 by conjugation with the aid of plasmid RP4 at a frequency of $10^{-5}$ per recipient. This plasmid was stable in A. thiooxidans. The pfkA gene from E. coli could be expressed in this obligately autotrophic bacterium, but the enzyme activity (21.6 U/g protein) was lower than that in E. coli (K12: 85.9 Dig protein; DF1010 carrying plasmid pSDK-l: 96.6 U/g protein). In the presence of glucose, the Tt-7 transconjugants consumed glucose, leading to a better growth yield.

Soluble Expression and Purification of the Catalytic Domain of Human Vascular Endothelial Growth Factor Receptor 2 in Escherichia coli

  • Wei, Jia;Cao, Xiaodan;Zhou, Shengmin;Chen, Chao;Yu, Haijun;Zhou, Yao;Wang, Ping
    • Journal of Microbiology and Biotechnology
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    • v.25 no.8
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    • pp.1227-1233
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    • 2015
  • Vascular endothelial growth factor (VEGF) plays a key role in angiogenesis through binding to its specific receptors, which mainly occurs to VEGF receptor 2 (VEGFR-2), a kinase insert domain-containing receptor. Therefore, the disruption of VEGFR-2 signaling provides a promising therapeutic approach for the treatment of cancer by inhibiting abnormal or tumorinduced angiogenesis. To explore this potential, we expressed the catalytic domain of VEGFR-2 (VEGFR-2-CD) as a soluble active kinase in Escherichia coli. The recombinant protein was purified and the VEGFR-2-CD activity was investigated. The obtained VEGFR-2-CD showed autophosphorylation activity and phosphate transfer activity comparable to the commercial enzyme. Furthermore, the IC50 value of known VEGFR-2 inhibitor was determined using the purified VEGFR-2-CD. These results indicated a possibility for functional and economical VEGFR-2-CD expression in E. coli to use for inhibitor screening.

MEVVA ion Source And Filtered Thin-Film Deposition System

  • Liu, A.D.;Zhang, H.X.;Zhang, T.H.;Zhang, X.Y.;Wu, X.Y.;Zhang, S.J.;Li, Q.
    • Journal of Korean Vacuum Science & Technology
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    • v.6 no.2
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    • pp.55-57
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    • 2002
  • Metal-vapor-vacuum-arc ion source is an ideal source for both high current metal ion implanter and high current plasma thin-film deposition systems. It uses the direct evaporation of metal from surface of cathode by vacuum arc to produce a very high flux of ion plasmas. The MEVVA ion source, the high-current metal-ion implanter and high-current magnetic-field-filtered plasma thin-film deposition systems developed in Beijing Normal University are introduced in this paper.

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A rapid modeling method and accuracy criteria for common-cause failures in Risk Monitor PSA model

  • Zhang, Bing;Chen, Shanqi;Lin, Zhixian;Wang, Shaoxuan;Wang, Zhen;Ge, Daochuan;Guo, Dingqing;Lin, Jian;Wang, Fang;Wang, Jin
    • Nuclear Engineering and Technology
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    • v.53 no.1
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    • pp.103-110
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    • 2021
  • In the development of a Risk Monitor probabilistic safety assessment (PSA) model from the basic PSA model of a nuclear power plant, the modeling of common-cause failure (CCF) is very important. At present, some approximate modeling methods are widely used, but there lacks criterion of modeling accuracy and error analysis. In this paper, aiming at ensuring the accuracy of risk assessment and minimizing the Risk Monitor PSA models size, we present three basic issues of CCF model resulted from the changes of a nuclear power plant configuration, put forward corresponding modeling methods, and derive accuracy criteria of CCF modeling based on minimum cut sets and risk indicators according to the requirements of risk monitoring. Finally, a nuclear power plant Risk Monitor PSA model is taken as an example to demonstrate the effectiveness of the proposed modeling method and accuracy criteria, and the application scope of the idea of this paper is also discussed.