Development of a Virus Concentration Method and its Application for the Detection of Noroviruses in Drinking Water in China

Liu, Junyi,Wu, Qingping,Kou, Xiaoxia The Microbiological Society of Korea 2007 The journal of microbiology Vol.45 No.1

A new procedure for the concentration of nonoviruses from water samples has been developed. This procedure (calcium flocculation-citrate dissolution method) uses the following steps: virus flocculation formed by treatment with 1 M $CaCl_2$ and 1 M $Na_2HPO_4$, virus release by sodium citrate dissolution (0.3 M Na citrate, pH 3.5), and virus re-concentration by ultrafiltration. When reverse transcription (RT)-PCR was performed after the procedure, the overall detection sensitivity for seeded noroviruses in a one liter drinking water sample was as low as 1 RT-PCR unit, which is equal to a $10^{-6}$ dilution of the virus sample. This approach showed at least a 5-fold-higher sensitivity than the current method with its three steps of adsorption-elution-concentration. The newly developed procedure was used to test different brands of bottled drinking water from China for putative contamination with noroviruses. A total of 144 samples were analyzed; all of the samples were negative for norovirus specific nucleic acids.

Development of a Virus Concentration Method and its Application for the Detection of Noroviruses in Drinking Water in China

Junyi Liu,Qingping Wu,Xiaoxia Kou 한국미생물학회 2007 The journal of microbiology Vol.45 No.1

A new procedure for the concentration of nonoviruses from water samples has been developed. This procedure (calcium flocculation-citrate dissolution method) uses the following steps: virus flocculation formed by treatment with 1 M CaCl2 and 1 M Na2HPO4, virus release by sodium citrate dissolution (0.3 M Na citrate, pH 3.5), and virus reconcentration by ultrafiltration. When reverse transcription (RT)-PCR was performed after the procedure, the overall detection sensitivity for seeded noroviruses in a one liter drinking water sample was as low as 1 RT-PCR unit, which is equal to a 10-6 dilution of the virus sample. This approach showed at least a 5-fold-higher sensitivity than the current method with its three steps of adsorption-elution-concentration. The newly developed procedure was used to test different brands of bottled drinking water from China for putative contamination with noroviruses. A total of 144 samples were analyzed; all of the samples were negative for norovirus specific nucleic acids.

Joint wireless and computational resource allocation for ultra-dense mobile-edge computing networks

( Junyi Liu ),( Hongbing Huang ),( Yijun Zhong ),( Jiale He ),( Tiancong Huang ),( Qian Xiao ),( Weiheng Jiang ) 한국인터넷정보학회 2020 KSII Transactions on Internet and Information Syst Vol.14 No.7

In this paper, we study the joint radio and computational resource allocation in the ultra-dense mobile-edge computing networks. In which, the scenario which including both computation offloading and communication service is discussed. That is, some mobile users ask for computation offloading, while the others ask for communication with the minimum communication rate requirements. We formulate the problem as a joint channel assignment, power control and computational resource allocation to minimize the offloading cost of computing offloading, with the precondition that the transmission rate of communication nodes are satisfied. Since the formulated problem is a mixed-integer nonlinear programming (MINLP), which is NP-hard. By leveraging the particular mathematical structure of the problem, i.e., the computational resource allocation variable is independent with other variables in the objective function and constraints, and then the original problem is decomposed into a computational resource allocation subproblem and a joint channel assignment and power allocation subproblem. Since the former is a convex programming, the KKT (Karush-Kuhn-Tucker) conditions can be used to find the closed optimal solution. For the latter, which is still NP-hard, is further decomposed into two subproblems, i.e., the power allocation and the channel assignment, to optimize alternatively. Finally, two heuristic algorithms are proposed, i.e., the Co-channel Equal Power allocation algorithm (CEP) and the Enhanced CEP (ECEP) algorithm to obtain the suboptimal solutions. Numerical results are presented at last to verify the performance of the proposed algorithms.

Effect of sulfate activators on mechanical property of high replacement low-calcium ultrafine fly ash blended cement paste

Liu, Baoju,Tan, Jinxia,Shi, Jinyan,Liang, Hui,Jiang, Junyi,Yang, Yuanxia Techno-Press 2021 Advances in concrete construction Vol.11 No.3

Due to economic and environmental benefits, increasing the substitution ratio of ordinary cement by industry by-products like fly ash (FA) is one of the best approaches to reduce the impact of the concrete industry on the environment. However, as the substitution rate of FA increases, it will have an adverse impact on the performance of cement-based materials, so the actual substitution rate of FA is limited to around 10-30%. Therefore, in order to increase the early-age strength of high replacement (30-70%) low-calcium ultrafine FA blended cement paste, sodium sulfate and calcium sulfate dihydrate were used to improve the reactivity of FA. The results show that sodium sulfate has a significant enhancement effect on the strength of the composite pastes in the early and late ages, while calcium sulfate dihydrate has only a slight effect in the late ages. The addition of sodium sulfate in the cement-FA blended system can enhance the gain rate of non-evaporation water, and can decrease the Ca(OH)2 content. In addition, when the sulfate chemical activators are added, the ettringite content increases, and the surface of the FA is dissolved and hydrated.

Effect of cement as mineral filler on the performance development of emulsified asphalt concrete

Liu, Baoju,Wu, Xiang,Shi, Jinyan,Wu, Xiaolong,Jiang, Junyi,Qin, Jiali Techno-Press 2020 Advances in concrete construction Vol.10 No.6

Cold-mixed asphalt mixture is a widely recommended asphalt pavement materials with potentially economic and environmental benefits. Due to the reduction of natural non-renewable mineral resources, powder minerals with similar properties are considered as new mineral fillers in asphalt mixtures. This study explored the feasibility of using cement to replace natural limestone powder (LP) in emulsified asphalt concrete modified by styrene-butadiene styrene copolymer. The experimental tests, including compressive strength, Marshall stability as well as moisture susceptibility test, were used to investigate the mechanical properties, the Marshall stability, flow value, as well as the moisture damage. In addition, the influence of material composition on the performance of asphalt concrete is explained by the microstructure evolution of the pore structure, the interface transition zone (ITZ), and the micromorphology. Due to mineralogical reactivity of cement, its replacement part of LP improved the mechanical properties, Marshall stability, but it will reduce the moisture susceptibility and flow value. This is because with the increase of the cement substitution rate, the pore structure of the asphalt concrete is refined, the width of ITZ becomes smaller, and the microstructure is more compact. In addition, asphalt concrete with a larger nominal particle size (AC-16) has relatively better performance.

<i>In Situ</i> Activation of Nitrogen-Doped Graphene Anchored on Graphite Foam for a High-Capacity Anode

Ji, Junyi,Liu, Jilei,Lai, Linfei,Zhao, Xin,Zhen, Yongda,Lin, Jianyi,Zhu, Yanwu,Ji, Hengxing,Zhang, Li Li,Ruoff, Rodney S. American Chemical Society 2015 ACS NANO Vol.9 No.8

<P>We report the fabrication of a three-dimensional free-standing nitrogen-doped porous graphene/graphite foam by <I>in situ</I> activation of nitrogen-doped graphene on highly conductive graphite foam (GF). After <I>in situ</I> activation, intimate “sheet contact” was observed between the graphene sheets and the GF. The sheet contact produced by <I>in situ</I> activation is found to be superior to the “point contact” obtained by the traditional drop-casting method and facilitates electron transfer. Due to the intimate contact as well as the use of an ultralight GF current collector, the composite electrode delivers a gravimetric capacity of 642 mAh g<SUP>–1</SUP> and a volumetric capacity of 602 mAh cm<SUP>–3</SUP> with respect to the whole electrode mass and volume (including the active materials and the GF current collector). When normalized based on the mass of the active material, the composite electrode delivers a high specific capacity of up to 1687 mAh g<SUP>–1</SUP>, which is superior to that of most graphene-based electrodes. Also, after ∼90 s charging, the anode delivers a capacity of about 100 mAh g<SUP>–1</SUP> (with respect to the total mass of the electrode), indicating its potential use in high-rate lithium-ion batteries.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancac3/2015/ancac3.2015.9.issue-8/acsnano.5b03888/production/images/medium/nn-2015-03888k_0006.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nn5b03888'>ACS Electronic Supporting Info</A></P>

Degrees of Freedom of Multi-Cell MIMO Interference Broadcast Channels With Distributed Base Stations

( Hongbing Huang ),( Junyi Liu ),( Yi Zhang ),( Qing Cai ),( Bowei Zhang ),( Fengwen Jiang ) 한국인터넷정보학회 2019 KSII Transactions on Internet and Information Syst Vol.13 No.2

In this paper, we investigate the degrees of freedom (DoF) of a multi-cell multi-user multiple-input multiple-output (MIMO) interference broadcast channel (IBC) with non-cooperation distributed base stations (BS), where each BS serves users of its corresponding cell. When all BSs simultaneously transmit their own signals over the same frequency band in the MIMO IBC, the edge users in each cell will suffer the inter-cell interference (ICI) and inter-user interference (IUI) signals. In order to eliminate the ICI and IUI signals, a distributed space time interference alignment (DSTIA) approach is proposed where each BS has only limited access to distributed moderately-delay channel state information at the transmitter (CSIT). It is shown that the DSTIA scheme can obtain the appreciate DoF gains. In addition, the DoF upper bound is asymptotically achievable as the number of antenna at each BS increases. It is shown that the DSTIA method can get DoF gains over other interference alignment schemes with delayed CSIT in literature. Moreover, the DSTIA method can attain higher DoFs than the IA schemes with global CSIT for certain antenna configurations.

Business Software Rapid Development Platform based on SOA

Haigen Yang,Xiaoting Rui,Yixin Liu,Junyi He 보안공학연구지원센터 2013 International Journal of Database Theory and Appli Vol.6 No.3

The genome of the mesopolyploid crop species Brassica rapa

Wang, Xiaowu,Wang, Hanzhong,Wang, Jun,Sun, Rifei,Wu, Jian,Liu, Shengyi,Bai, Yinqi,Mun, Jeong-Hwan,Bancroft, Ian,Cheng, Feng,Huang, Sanwen,Li, Xixiang,Hua, Wei,Wang, Junyi,Wang, Xiyin,Freeling, Michael Nature Publishing Group, a division of Macmillan P 2011 Nature genetics Vol.43 No.10

We report the annotation and analysis of the draft genome sequence of Brassica rapa accession Chiifu-401-42, a Chinese cabbage. We modeled 41,174 protein coding genes in the B. rapa genome, which has undergone genome triplication. We used Arabidopsis thaliana as an outgroup for investigating the consequences of genome triplication, such as structural and functional evolution. The extent of gene loss (fractionation) among triplicated genome segments varies, with one of the three copies consistently retaining a disproportionately large fraction of the genes expected to have been present in its ancestor. Variation in the number of members of gene families present in the genome may contribute to the remarkable morphological plasticity of Brassica species. The B. rapa genome sequence provides an important resource for studying the evolution of polyploid genomes and underpins the genetic improvement of Brassica oil and vegetable crops.