Chloride Ion Invasive Behavior of Recycled Aggregate Concrete under Coupling Flexural Loading and Wetting-Drying Cycles

Guoliang Bai,Chao Zhu,Chao Liu,Huawei Liu 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.10

In this paper, the invasive behavior of chloride ion has been investigated under the coupling action of wetting-drying cycles and flexural load on recycled aggregate concrete (RAC) beams in sodium chloride solution. The permeation properties of chloride in RAC were studied by analyzing the content, binding capacity and diffusion coefficient of chloride. The priority of interfacial transition zone (ITZ) for chloride transport in RAC was analyzed by energy dispersive spectrometer (EDS). Additionally, the distribution of chloride content in concrete was predicted. The results indicated that the micro-pore structure, initial damage and micro-cracks provide more paths for the diffusion of chloride in the RAC. The binding capacity of chloride diminished with the incorporation of recycled coarse aggregate (RCA) and the exertion of flexural load, which increased the chloride diffusion coefficient. The correctness of Fick's second diffusion law was verified via applying it to the data processing. Furthermore, the convection and diffusion zones had the significant influence on the distribution of chloride.

Transplanting neurofibromatosis-1 gene knockout neural stem cells improve functional recovery in rats with spinal cord injury by enhancing the mTORC2 pathway

Chen Guoliang,Li Xianlong,Zhu Hongzhang,Wu Huachuan,He Dacheng,Shi Liangyu,Wei Fuxin,Liu Xizhe,Chen Ningning,Liu Shaoyu 생화학분자생물학회 2022 Experimental and molecular medicine Vol.54 No.-

The poor survival and low efficiency of neuronal differentiation limits the therapeutic effects of transplanted neural stem cells in the treatment of spinal cord injury. Neurofibromatosis-1 (NF-1) is a tumor suppressor gene that restricts the rapid and abnormal growth and differentiation of neural cells. In the present study, lentiviral vectors were used to knock out NF-1, Ricotr (the core member of mTORC2) or NF-1+Ricotr in neural stem cells in vitro, and the NF-1, Ricotr or NF-1+Ricotr knockout neural stem cells were transplanted at the lesion site in a rat model of spinal cord injury (SCI). We first demonstrated that targeted knockout of NF-1 had an antiapoptotic effect and improved neuronal differentiation by enhancing the mTORC2/Rictor pathway of neural stem cells in vitro. Subsequently, transplanting NF-1 knockout neural stem cells into the injured site sufficiently promoted the tissue repair and functional recovery of rats with spinal cord injury by enhancing the survival and neuronal differentiation of grafted neural stem cells. Collectively, these findings reveal a prominent role of NF-1 in neural stem cell biology, which is an invaluable step forward in enhancing the benefit of neural stem cell-mediated regenerative cell therapy for spinal cord injury and identifies the transplantation of NF-1 knockout neural stem cells as a promising strategy for spinal cord injury.

Intensity of Intraoperative Spinal Cord Hyperechogenicity as a Novel Potential Predictive Indicator of Neurological Recovery for Degenerative Cervical Myelopathy

Chen Guoliang,Wei Fuxin,Li Jiachun,Shi Liangyu,Zhang Wei,Wang Xianxiang,Xu Zuofeng,Liu Xizhe,Zou Xuenong,Liu Shaoyu 대한영상의학회 2021 Korean Journal of Radiology Vol.22 No.7

Objective: To analyze the correlations between intraoperative ultrasound and MRI metrics of the spinal cord in degenerative cervical myelopathy and identify novel potential predictive ultrasonic indicators of neurological recovery for degenerative cervical myelopathy. Materials and Methods: Twenty-two patients who underwent French-door laminoplasty for multilevel degenerative cervical myelopathy were followed up for 12 months. The Japanese Orthopedic Association (JOA) scores were assessed preoperatively and 12 months postoperatively. Maximum spinal cord compression and compression rates were measured and calculated using both intraoperative ultrasound imaging and preoperative T2-weight (T2W) MRI. Signal change rates of the spinal cord on preoperative T2W MRI and gray value ratios of dorsal and ventral spinal cord hyperechogenicity on intraoperative ultrasound imaging were measured and calculated. Correlations between intraoperative ultrasound metrics, MRI metrics, and the recovery rate JOA scores were analyzed using Spearman correlation analysis. Results: The postoperative JOA scores improved significantly, with a mean recovery rate of 65.0 ± 20.3% (p < 0.001). No significant correlations were found between the operative ultrasound metrics and MRI metrics. The gray value ratios of the spinal cord hyperechogenicity was negatively correlated with the recovery rate of JOA scores (ρ = -0.638, p = 0.001), while the ventral and dorsal gray value ratios of spinal cord hyperechogenicity were negatively correlated with the recovery rate of JOA-motor scores (ρ = -0.582, p = 0.004) and JOA-sensory scores (ρ = -0.452, p = 0.035), respectively. The dorsal gray value ratio was significantly higher than the ventral gray value ratio (p < 0.001), while the recovery rate of JOA-motor scores was better than that of JOA-sensory scores at 12 months post-surgery (p = 0.028). Conclusion: For degenerative cervical myelopathy, the correlations between intraoperative ultrasound and preoperative T2W MRI metrics were not significant. Gray value ratios of the spinal cord hyperechogenicity and dorsal and ventral spinal cord hyperechogenicity were significantly correlated with neurological recovery at 12 months postoperatively.

An Adaptive Energy-Efficient and Low-Latency MAC Protocol for Wireless Sensor Networks

Liu, Hao,Yao, Guoliang,Wu, Jianhui,Shi, Longxing The Korea Institute of Information and Commucation 2010 Journal of communications and networks Vol.12 No.5

In this paper, an adaptive MAC protocol (variable load adaptive (VLA)-MAC) is proposed for wireless sensor networks. This protocol can achieve high energy efficiency and provide low latency under variable-traffic-load conditions. In the case of VLA-MAC, traffic load is measured online and used for adaptive adjustment. Sensor nodes transmit packets in bursts under high load conditions to alleviate packet accumulation and reduce latency. This also removes unnecessary listen action and decreases energy consumption in low load conditions. Simulation results show that the energy efficiency, latency, and throughput achieved by VLA-MAC are higher than those achieved by some traditional approaches.

Effect of Supports on Soot Oxidation of Copper Catalysts: BaTiO3 Versus Fe2O3@BaTiO3 Core/Shell Microsphere

Guoliang Fan,Liu Zhao,Cairong Gong,Jia Ma,Gang Xue 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2016 NANO Vol.11 No.1

Copper catalysts prepared using two kinds of supports (BaTiO3 and Fe2O3@BaTiO3) have been tested for soot combustion. Perovskite-type oxide BaTiO3 shows excellent properties as support but has small specific surface area. Fe2O3@BaTiO3 core/shell microspheres, as improved support of BaTiO3 support, were fabricated by a hydrothermal-annealing approach. Fe2O3@BaTiO3 support has large specific surface area, which optimizes the contact condition of the gassoot-catalyst three-phase reaction. Due to the Cu-Fe2O3@BaTiO3 interaction, the redox properties of copper are improved. Soot combustion is tested under O2 gas flow and NOx/O2 gas flow, and Fe2O3@BaTiO3 supported copper catalyst (Cu/Fe2O3@BaTiO3) all shows higher catalytic activity and CO2 selectivity than BaTiO3 supported copper catalyst (Cu/BaTiO3).

Experimental Study on Dynamic Tensile Properties of Macro-Polypropylene Fiber Reinforced Cementitious Composites

Guoliang Yang,Jingjiu Bi,Zhiwen Dong,Ying Li,Yi Liu 한국콘크리트학회 2023 International Journal of Concrete Structures and M Vol.17 No.1

Using a high-speed photography system and a split Hopkinson pressure bar, macro-polypropylene fiber reinforced cementitious composites are tested to reveal the effects of the macro-polypropylene fiber volume fraction and loading rate on the dynamic tensile strength and failure mode. We also analyze the functional relationship between the dynamic tensile strength, loading rate, and fiber volume fraction, and study the splitting failure process using digital image correlation technology. The evolution law of the strain and displacement fields of the specimens is obtained, and the effect of the fiber volume fraction on the crack initiation strain value is quantitatively studied. The results show that the appropriate fiber content (1.5–2%) can significantly improve the dynamic tensile strength, while a higher fiber content (2.5%) leads to deterioration of the specimen. Adding macro-polypropylene fiber prevents the specimen from undergoing central tensile fracturing under dynamic loading, and distributes the impact load more evenly, thus improving the ability of the specimen to resist cracking.

CO catalytic oxidation over graphene with double vacancy‑embedded molybdenum: a DFT investigation

Guoliang Dai,Jiahui Liu,Hui Qian 한국탄소학회 2019 Carbon Letters Vol.29 No.4

Based on the M06-2X density functional, the catalytic oxidation of CO by O2 over Mo-embedded graphene was investigated in detail. The model with molybdenum atom embedded in double vacancy (DV) in a graphene sheet was considered. It is found that the complete CO oxidation reactions over Mo-DV-graphene include a two-step process, in which the first step prefers to Langmuir–Hinshelwood mechanism and followed the progress of CO oxidation with a remaining atomic Otop. Compared with the structure of Mo atom decorated at the single carbon vacancy on graphene (Mo-SV-graphene), the catalytic activity of Mo-DV-graphene is weaker. The present results imply that the catalytic activity of Mo-embedded graphene for CO oxidation can be improved by increasing the ratio of single vacancy (SV).

Characteristics and Regulating Role in Thermotolerance of the Heat Shock Transcription Factor ZmHsf12 from Zea mays L.

Guoliang Li,Yuanyuan Zhang,Huaning Zhang,Yujie Zhang,Lina Zhao,Zihui Liu,Xiulin Guo 한국식물학회 2019 Journal of Plant Biology Vol.62 No.5

Plant heat shock transcription factors (Hsfs) areimportant regulators of heat shock signal transduction pathway. There are 30 members of the Hsf family in maize, only twoof which, ZmHsf06 and ZmHsf12, belong to subclass A1. Our previous work demonstrated that ZmHsf06-overexpressingArabidopsis lines showed improved tolerance to heat anddrought stresses. In this study, we isolated ZmHsf12 fromyoung leaves of maize (Zea mays L.) using homologouscloning methods. The CDS (coding sequence) of ZmHsf12 is1,494 bp and encodes a putative protein consisting of 497amino acids which possesses domains such as DBD (DNAbindingdomain), OD (oligomerization domain), NLS (nuclearlocalization signal), NES (nuclear export signal), and anAHA (activator) motif. The ZmHsf12-GFP fusion protein islocalized to the cell nucleus. ZmHsf12 was expressed inmany maize organs, and its expression was up-regulated byheat shock. Furthermore, we characterized the function ofZmHsf12 in yeast and Arabidopsis. Yeast cells overexpressingZmHsf12 showed enhanced heat tolerance. ZmHsf12-overexpressing Arabidopsis seedlings displayed significantincreases in both basal and acquired thermotolerance. Comparedto WT seedlings, the ZmHsf12-overexpressing lines displayedboth increased chlorophyll contents and higher survivalrates. Also, the expression of AtHsps was increased higher inthe ZmHsf12-overexpressing Arabidopsis lines after heatstress. The results of our study strongly suggested thatZmHsf12 may take part in plant response to heat stress.

CO catalytic oxidation over graphene with double vacancy-embedded molybdenum: a DFT investigation

Dai Guoliang,Liu Jiahui,Qian Hui 한국탄소학회 2019 Carbon Letters Vol.29 No.4

Based on the M06-2X density functional, the catalytic oxidation of CO by O2 over Mo-embedded graphene was investigated in detail. The model with molybdenum atom embedded in double vacancy (DV) in a graphene sheet was considered. It is found that the complete CO oxidation reactions over Mo-DV-graphene include a two-step process, in which the first step prefers to Langmuir–Hinshelwood mechanism and followed the progress of CO oxidation with a remaining atomic Otop. Compared with the structure of Mo atom decorated at the single carbon vacancy on graphene (Mo-SV-graphene), the catalytic activity of Mo-DV-graphene is weaker. The present results imply that the catalytic activity of Mo-embedded graphene for CO oxidation can be improved by increasing the ratio of single vacancy (SV).

An Adaptive Energy-Efficient and Low-Latency MAC Protocol forWireless Sensor Networks

Hao Liu,Guoliang Yao,Jianhui Wu,Longxing Shi 한국통신학회 2010 Journal of communications and networks Vol.12 No.5

In this paper, an adaptive MAC protocol (variable load adaptive (VLA)-MAC) is proposed for wireless sensor networks. This protocol can achieve high energy efficiency and provide low latency under variable-traffic-load conditions. In the case of VLA-MAC, traffic load is measured online and used for adaptive adjustment. Sensor nodes transmit packets in bursts under high load conditions to alleviate packet accumulation and reduce latency. This also removes unnecessary listen action and decreases energy consumption in low load conditions. Simulation results show that the energy efficiency, latency, and throughput achieved by VLA-MAC are higher than those achieved by some traditional approaches.