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  1. Article ; Online: A Study on the Properties of Composite Modified Mortar with Styrene-Butadiene Rubber Latex and Silica Fume.

    Yan, Renwei / Wang, Laifa / Ni, Yongjun / Zhang, Shuowen / He, Zhenqing / Guan, Bowen

    Polymers

    2024  Volume 16, Issue 5

    Abstract: To solve the problem of the poor abrasion resistance of concrete pavement surface mortar, this study substituted cement with equal amounts of styrene-butadiene rubber (SBR) latex and silica fume (SF) to investigate the effects of organic/inorganic ... ...

    Abstract To solve the problem of the poor abrasion resistance of concrete pavement surface mortar, this study substituted cement with equal amounts of styrene-butadiene rubber (SBR) latex and silica fume (SF) to investigate the effects of organic/inorganic material composite modification on the fluidity, drying shrinkage, mechanical properties, and abrasion resistance of cement mortar. Also in this study, the microstructure, product, and pore structure characteristics of the composite modified cement mortar were investigated using scanning electron microscope (SEM), X-Ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), and the Brunauer-Emmett-Teller (BET) method. This research found that the sole substitution of SF negatively impacted the mortar's fluidity and drying shrinkage yet enhanced its mechanical strength and abrasion resistance; the incorporation of SBR latex improved fluidity, reduced shrinkage, and increased flexural strength but adversely affected the compressive strength of the mortar. Additionally, the enhancement of the mortar's abrasion resistance with SBR latex was significantly greater than that with SF. When SBR latex and SF were used together as substitutes, the latex struggled to offset the negative impact of SF on mortar fluidity but effectively reduced shrinkage; SF compensated for the detrimental effect of the latex on compressive strength. Moreover, the primary role in enhancing the mortar's abrasion resistance was played by the latex. Microscopic tests showed that SBR latex and SF could increase the content of calcium silicate hydrate (C-S-H) gel, inhibit the formation of ettringite (AFt) and reduce carbonation, refine the pore size of cement mortar, and effectively improve the microstructure of mortar.
    Language English
    Publishing date 2024-03-04
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2527146-5
    ISSN 2073-4360 ; 2073-4360
    ISSN (online) 2073-4360
    ISSN 2073-4360
    DOI 10.3390/polym16050697
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Book ; Online: Cascaded Channel Estimation for Large Intelligent Metasurface Assisted Massive MIMO

    He, Zhen-Qing / Yuan, Xiaojun

    2019  

    Abstract: In this letter, we consider the problem of channel estimation for large intelligent metasurface (LIM) assisted massive multiple-input multiple-output (MIMO) systems. The main challenge of this problem is that the LIM integrated with a large number of low- ...

    Abstract In this letter, we consider the problem of channel estimation for large intelligent metasurface (LIM) assisted massive multiple-input multiple-output (MIMO) systems. The main challenge of this problem is that the LIM integrated with a large number of low-cost metamaterial antennas can only passively reflect the incident signal by a certain phase shift, and does not have any signal processing capability. To deal with this, we introduce a general framework for the estimation of the transmitter-LIM and LIM-receiver cascaded channel, and propose a two-stage algorithm that includes a sparse matrix factorization stage and a matrix completion stage. Simulation results illustrate that the proposed method can achieve accurate channel estimation for LIM-assisted massive MIMO systems.

    Comment: 3 figures, 5 pages
    Keywords Computer Science - Information Theory ; Electrical Engineering and Systems Science - Signal Processing
    Subject code 003
    Publishing date 2019-05-20
    Publishing country us
    Document type Book ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  3. Article: Synergistic Effects from Combination of Cryptotanshinone and Fosfomycin Against Fosfomycin-Susceptible and Fosfomycin-Resistant

    Ruan, Zijing / Cui, Jiaqi / He, Zhenqing / Guo, Yuting / Jia, Xu / Huang, Xinhe

    Infection and drug resistance

    2020  Volume 13, Page(s) 2837–2844

    Abstract: Purpose: Fosfomycin is now widely used to treat methicillin-resistant : Methods: The MICs of fosfomycin and/or cryptanshinone were determined by agar dilution assay and checkerboard microdilution assay. Furthermore, synergistic effects from ... ...

    Abstract Purpose: Fosfomycin is now widely used to treat methicillin-resistant
    Methods: The MICs of fosfomycin and/or cryptanshinone were determined by agar dilution assay and checkerboard microdilution assay. Furthermore, synergistic effects from fosfomycin and/or cryptanshinone were analyzed by the time-kill assay in vitro.
    Results: The combination of fosfomycin and cryptotanshinone had a synergistic effect on most (71.43%) of the FRSA and had a partial (28.57%) synergistic effect on a small part. In addition, time sterilization curve verified synergistic activity between cryptanshinone and fosfomycin against FSSA and FRSA, especially when fosfomycin was added for a second time.
    Conclusion: These data suggest that cryptanshinone combined with fosfomycin could be a novel treatment for FRSA and provide a new direction for the treatment of bacterial infections in the future.
    Language English
    Publishing date 2020-08-13
    Publishing country New Zealand
    Document type Journal Article
    ZDB-ID 2494856-1
    ISSN 1178-6973
    ISSN 1178-6973
    DOI 10.2147/IDR.S255296
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  4. Article ; Online: SARS-CoV-2 and SARS-CoV: Virtual screening of potential inhibitors targeting RNA-dependent RNA polymerase activity (NSP12).

    Ruan, Zijing / Liu, Chao / Guo, Yuting / He, Zhenqing / Huang, Xinhe / Jia, Xu / Yang, Tai

    Journal of medical virology

    2020  Volume 93, Issue 1, Page(s) 389–400

    Abstract: Since the outbreak of severe acute respiratory syndrome (SARS) in 2003, the harm caused by coronaviruses to the world cannot be underestimated. Recently, a novel coronavirus (severe acute respiratory syndrome coronavirus-2 [SARS-CoV-2]) initially found ... ...

    Abstract Since the outbreak of severe acute respiratory syndrome (SARS) in 2003, the harm caused by coronaviruses to the world cannot be underestimated. Recently, a novel coronavirus (severe acute respiratory syndrome coronavirus-2 [SARS-CoV-2]) initially found to trigger human severe respiratory illness in Wuhan City of China in 2019, has infected more than six million people worldwide by 21 June 2020, and which has been recognized as a public health emergency of international concern as well. And the virus has spread to more than 200 countries around the world. However, the effective drug has not yet been officially licensed or approved to treat SARS-Cov-2 and SARS-Cov infection. NSP12-NSP7-NSP8 complex of SARS-CoV-2 or SARS-CoV, essential for viral replication and transcription, is generally regarded as a potential target to fight against the virus. According to the NSP12-NSP7-NSP8 complex (PDB ID: 7BW4) structure of SARS-CoV-2 and the NSP12-NSP7-NSP8 complex (PDB ID: 6NUR) structure of SARS-CoV, NSP12-NSP7 interface model, and NSP12-NSP8 interface model were established for virtual screening in the present study. Eight compounds (Nilotinib, Saquinavir, Tipranavir, Lonafarnib, Tegobuvir, Olysio, Filibuvir, and Cepharanthine) were selected for binding free energy calculations based on virtual screening and docking scores. All eight compounds can combine well with NSP12-NSP7-NSP8 in the crystal structure, providing drug candidates for the treatment and prevention of coronavirus disease 2019 and SARS.
    MeSH term(s) Antiviral Agents/pharmacology ; Coronavirus RNA-Dependent RNA Polymerase/antagonists & inhibitors ; Drug Discovery/methods ; Models, Molecular ; Molecular Docking Simulation ; SARS Virus/drug effects ; SARS-CoV-2/drug effects ; Small Molecule Libraries
    Chemical Substances Antiviral Agents ; Small Molecule Libraries ; Coronavirus RNA-Dependent RNA Polymerase (EC 2.7.7.48) ; NSP12 protein, SARS-CoV-2 (EC 2.7.7.48)
    Keywords covid19
    Language English
    Publishing date 2020-07-09
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 752392-0
    ISSN 1096-9071 ; 0146-6615
    ISSN (online) 1096-9071
    ISSN 0146-6615
    DOI 10.1002/jmv.26222
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    In stock of ZB MED Cologne/Königswinter

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  5. Book ; Online: Variance State Propagation for Structured Sparse Bayesian Learning

    Zhang, Mingchen / Yuan, Xiaojun / He, Zhen-Qing

    2019  

    Abstract: We propose a compressed sensing algorithm termed variance state propagation (VSP) for block-sparse signals, i.e., sparse signals that have nonzero coefficients occurring in clusters. The VSP algorithm is developed under the Bayesian framework. A ... ...

    Abstract We propose a compressed sensing algorithm termed variance state propagation (VSP) for block-sparse signals, i.e., sparse signals that have nonzero coefficients occurring in clusters. The VSP algorithm is developed under the Bayesian framework. A hierarchical Gaussian prior is introduced to depict the clustered patterns in the sparse signal. Markov random field (MRF) is introduced to characterize the state of the variances of the Gaussian priors. Such a hierarchical prior has the potential to encourage clustered patterns and suppress isolated coefficients whose patterns are different from their respective neighbors. The core idea of our algorithm is to iteratively update the variances in the prior Gaussian distribution. The message passing technique is employed in the design of the algorithm. For messages that are difficult to calculate, we correspondingly design reasonable methods to achieve approximate calculations. The hyperparameters can be updated within the iteration process. Simulation results demonstrate that the VSP algorithm is able to handle a variety of block-sparse signal recovery tasks and presents a significant advantage over the existing methods.
    Keywords Electrical Engineering and Systems Science - Signal Processing ; Computer Science - Information Theory
    Subject code 006
    Publishing date 2019-10-16
    Publishing country us
    Document type Book ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  6. Book ; Online: Semi-Blind Cascaded Channel Estimation for Reconfigurable Intelligent Surface Aided Massive MIMO

    He, Zhen-Qing / Liu, Hang / Yuan, Xiaojun / Zhang, Ying-Jun Angela / Liang, Ying-Chang

    2021  

    Abstract: Reconfigurable intelligent surface (RIS) is envisioned to be a promising green technology to reduce the energy consumption and improve the coverage and spectral efficiency of massive multiple-input multiple-output (MIMO) wireless networks. In a RIS-aided ...

    Abstract Reconfigurable intelligent surface (RIS) is envisioned to be a promising green technology to reduce the energy consumption and improve the coverage and spectral efficiency of massive multiple-input multiple-output (MIMO) wireless networks. In a RIS-aided MIMO system, the acquisition of channel state information (CSI) is important for achieving passive beamforming gains of the RIS, but is also challenging due to the cascaded property of the transmitter-RIS-receiver channel and the lack of signal processing capability of the passive RIS elements. The state-of-the-art approach for CSI acquisition in such a system is a pure training-based strategy that depends on a long sequence of pilot symbols. In this paper, we investigate semi-blind cascaded channel estimation for RIS-aided massive MIMO systems, in which the receiver simultaneously estimates the channel coefficients and the partially unknown transmit signal with a small number of pilot sequences. Specifically, we formulate the semi-blind cascaded channel estimation as a trilinear matrix factorization task. Under the Bayesian inference framework, we develop a computationally efficient iterative algorithm using the approximate message passing principle to resolve the trilinear inference problem. Meanwhile, we present an analytical framework to characterize the theoretical performance bound of the proposed approach in the large-system limit via the replica method developed in statistical physics. Extensive simulation results demonstrate the effectiveness of the proposed semi-blind cascaded channel estimation algorithm.
    Keywords Computer Science - Information Theory
    Subject code 003
    Publishing date 2021-01-18
    Publishing country us
    Document type Book ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  7. Book ; Online: Passive Beamforming and Information Transfer Design for Reconfigurable Intelligent Surfaces Aided Multiuser MIMO Systems

    Yan, Wenjing / Yuan, Xiaojun / He, Zhen-Qing / Kuai, Xiaoyan

    2019  

    Abstract: This paper investigates the passive beamforming and information transfer (PBIT) technique for the multiuser multiple-input multiple-output (MIMO) systems with the aid of a reconfigurable intelligent surface (RIS), where the RIS enhances the primary ... ...

    Abstract This paper investigates the passive beamforming and information transfer (PBIT) technique for the multiuser multiple-input multiple-output (MIMO) systems with the aid of a reconfigurable intelligent surface (RIS), where the RIS enhances the primary communication via passive beamforming and at the same time delivers additional information by the spatial modulation (which adjusts the on-off states of the reflecting elements). For the passive beamforming design, we propose to maximize the sum channel capacity of the RIS-aided multiuser MIMO channel and formulate the problem as a two-step stochastic program. A sample average approximation (SAA) based iterative algorithm is developed for the efficient passive beamforming design of the considered scheme. To strike a balance between complexity and performance, we then propose a simplified beamforming algorithm by approximating the stochastic program as a deterministic alternating optimization problem. For the receiver design, the signal detection at the receiver is a bilinear estimation problem since the RIS information is multiplicatively modulated onto the reflected signals of the reflecting elements. To solve this bilinear estimation problem, we develop a turbo message passing (TMP) algorithm in which the factor graph associated with the problem is divided into two modules: one for the estimation of the user signals and the other for the estimation of the RIS's on-off states. The two modules are executed iteratively to yield a near-optimal low-complexity solution. Furthermore, we extend the design of the multiuser MIMO PBIT scheme from single-RIS to multi-RIS, by leveraging the similarity between the single-RIS and multi-RIS system models. Extensive simulation results are provided to demonstrate the advantages of our passive beamforming and receiver designs.

    Comment: 14 pages; 14 figures
    Keywords Computer Science - Information Theory ; Electrical Engineering and Systems Science - Signal Processing
    Subject code 003
    Publishing date 2019-12-21
    Publishing country us
    Document type Book ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  8. Article: SARS-CoV-2 and SARS-CoV: Virtual screening of potential inhibitors targeting RNA-dependent RNA polymerase activity (NSP12)

    Ruan, Zijing / Liu, Chao / Guo, Yuting / He, Zhenqing / Huang, Xinhe / Jia, Xu / Yang, Tai

    J. med. virol

    Abstract: Since the outbreak of severe acute respiratory syndrome (SARS) in 2003, the harm caused by coronaviruses to the world cannot be underestimated. Recently, a novel coronavirus (severe acute respiratory syndrome coronavirus-2 [SARS-CoV-2]) initially found ... ...

    Abstract Since the outbreak of severe acute respiratory syndrome (SARS) in 2003, the harm caused by coronaviruses to the world cannot be underestimated. Recently, a novel coronavirus (severe acute respiratory syndrome coronavirus-2 [SARS-CoV-2]) initially found to trigger human severe respiratory illness in Wuhan City of China in 2019, has infected more than six million people worldwide by 21 June 2020, and which has been recognized as a public health emergency of international concern as well. And the virus has spread to more than 200 countries around the world. However, the effective drug has not yet been officially licensed or approved to treat SARS-Cov-2 and SARS-Cov infection. NSP12-NSP7-NSP8 complex of SARS-CoV-2 or SARS-CoV, essential for viral replication and transcription, is generally regarded as a potential target to fight against the virus. According to the NSP12-NSP7-NSP8 complex (PDB ID: 7BW4) structure of SARS-CoV-2 and the NSP12-NSP7-NSP8 complex (PDB ID: 6NUR) structure of SARS-CoV, NSP12-NSP7 interface model, and NSP12-NSP8 interface model were established for virtual screening in the present study. Eight compounds (Nilotinib, Saquinavir, Tipranavir, Lonafarnib, Tegobuvir, Olysio, Filibuvir, and Cepharanthine) were selected for binding free energy calculations based on virtual screening and docking scores. All eight compounds can combine well with NSP12-NSP7-NSP8 in the crystal structure, providing drug candidates for the treatment and prevention of coronavirus disease 2019 and SARS.
    Keywords covid19
    Publisher WHO
    Document type Article
    Note WHO #Covidence: #612438
    Database COVID19

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  9. Article ; Online: SARS‐CoV‐2 and SARS‐CoV

    Ruan, Zijing / Liu, Chao / Guo, Yuting / He, Zhenqing / Huang, Xinhe / Jia, Xu / Yang, Tai

    Journal of Medical Virology ; ISSN 0146-6615 1096-9071

    Virtual screening of potential inhibitors targeting RNA‐dependent RNA polymerase activity (NSP12)

    2020  

    Keywords Virology ; Infectious Diseases ; covid19
    Language English
    Publisher Wiley
    Publishing country us
    Document type Article ; Online
    DOI 10.1002/jmv.26222
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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