Mechanical properties of pervious concrete with recycled aggregate

Xiangyi Zhu,Xudong Chen,Nan Shen,Huaxuan Tian,Xiangqian Fan,Jun Lu 사단법인 한국계산역학회 2018 Computers and Concrete, An International Journal Vol.21 No.6

In order to research the influence of different recycled aggregate contents on the mechanical properties of pervious concrete, the experimental study and numerical simulation analysis of the mechanical properties of pervious concrete with five kinds of recycled aggregates contents (0%, 25%, 50%, 75% and 100%) are carried out in this paper. The experimental test were first performed on concrete specimens of different sizes in order to determine the influence of recycled aggregate on the compressive strength and splitting tensile strength, direct tension strength and bending strength. Then, the development of the internal cracks of pervious concrete under different working conditions is studied more intuitively by PFC3D. The experimental results show that the concrete compressive strength, tensile strength and bending strength decrease with the increase of the recycled aggregate contents. This trend of reduction is not only related to the brittleness of recycled aggregate concrete, but also to the weak viscosity of recycled aggregate and cement paste. It is found that the fracture surface of pervious concrete with recycled aggregate is smoother than that of natural aggregate pervious concrete by PFC3D, which means that the bridging effect is weakened in the stress transfer between the left and right sides of the crack. Through the analysis of the development of the internal cracks, the recycled aggregate concrete generated more cracks than the natural aggregate concrete, which means that the recycled aggregate concrete is easier to form a coalescence fracture surface and eventually break.

Analysis of notch depth and loading rate effects on crack growth in concrete by FE and DIC

Xiangyi Zhu,Xudong Chen,Jun Lu,Xiangqian Fan 사단법인 한국계산역학회 2019 Computers and Concrete, An International Journal Vol.24 No.6

In this paper, the fracture characteristics of concrete specimens with different notch depths under three-point flexural loads are studied by finite element and fracture mechanics methods. Firstly, the concrete beams (the size is 700×100×150 mm) with different notch depths (a=30 mm, 45 mm, 60 mm and 75 mm respectively) are tested to study the influence of notch depths on the mechanical properties of concrete. Subsequently, the concrete beams with notch depth of 60 mm are loaded at different loading rates to study the influence of loading rates on the fracture characteristics, and digital image correlation (DIC) is used to monitor the strain nephogram at different loading rates. The test results show that the flexural characteristics of the beams are influenced by notch depths, and the bearing capacity and ductility of the concrete decrease with the increase of notch depths. Moreover, the peak load of concrete beam gradually increases with the increase of loading rate. Then, the fracture energy of the beams is accurately calculated by tail-modeling method and the bilinear softening constitutive model of fracture behavior is determined by using the modified fracture energy. Finally, the bilinear softening constitutive function is embedded into the finite element (FE) model for numerical simulation. Through the comparison of the test results and finite element analysis, the bilinear softening model determined by the tail-modeling method can be used to predict the fracture behavior of concrete beams under different notch depths and loading rates.

Core–shell ZIF-67(Co) wrapped CuO as high efficient peroxymonosulfate catalyst for the degradation of methylene blue

Zhu Wenjun,Zuo Xiaohua,Deng Xiangyi,Zhang Xinhao,Yao Chuang,Wang Xiaobo 한국탄소학회 2023 Carbon Letters Vol.33 No.2

Core–shell ZIFs wrapped CuO hybrid materials (CuO@ZIF-67(Co)) were designed, synthesized, characterized, and employed as peroxymonosulfate (PMS) activators to degrade methylene blue (MB). It demonstrated outstanding catalytic activity on account of the unique structure and the synergistic effect between CuO cores and ZIF-67(Co) shells, resulting in complete degradation of MB (10 mg/L) in 1 min. Reactive oxygen species (ROSs) research showed that both SO4− and OH were responsible for the removal of MB. The synergistic activation mechanisms in the CuO@ZIF-67(Co)/PMS system were investigated, which mainly involved the effective electron transfer of CuO and ZIF-67(Co) for accelerating the cycle of CuII/CuI and CoIII/CoII. This study broadens the application of MOF-derived materials for wastewater treatment.

MicroRNA-576-3p Inhibits Proliferation in Bladder Cancer Cells by Targeting Cyclin D1

Liang, Zhen,Li, Shiqi,Xu, Xin,Xu, Xianglai,Wang, Xiao,Wu, Jian,Zhu, Yi,Hu, Zhenghui,Lin, Yiwei,Mao, Yeqing,Chen, Hong,Luo, Jindan,Liu, Ben,Zheng, Xiangyi,Xie, Liping Korean Society for Molecular and Cellular Biology 2015 Molecules and cells Vol.38 No.2

MicroRNAs (miRNAs) are small, endogenous RNAs that play important gene-regulatory roles by binding to the imperfectly complementary sequences at the 3'-UTR of mRNAs and directing their gene expression. Here, we first discovered that miR-576-3p was down-regulated in human bladder cancer cell lines compared with the non-malignant cell line. To better characterize the role of miR-576-3p in bladder cancer cells, we over-expressed or down-regulated miR-576-3p in bladder cancer cells by transfecting with chemically synthesized mimic or inhibitor. The overexpression of miR-576-3p remarkably inhibited cell proliferation via G1-phase arrest, and decreased both mRNA and protein levels of cyclin D1 which played a key role in G1/S phase transition. The knock-down of miR-576-3p significantly promoted the proliferation of bladder cancer cells by accelerating the progression of cell cycle and increased the expression of cyclin D1. Moreover, the dual-luciferase reporter assays indicated that miR-576-3p could directly target cyclin D1 through binding its 3'-UTR. All the results demonstrated that miR-576-3p might be a novel suppressor of bladder cancer cell proliferation through targeting cyclin D1.

MicroRNA-409-3p Inhibits Migration and Invasion of Bladder Cancer Cells via Targeting c-Met

Xin Xu,Liping Xie,Hong Chen,Yiwei Lin,Zhenghui Hu,Yeqing Mao,Jian Wu,Xianglai Xu,Yi Zhu,Shiqi Li,Xiangyi Zheng 한국분자세포생물학회 2013 Molecules and cells Vol.36 No.1

There is increasing evidence suggesting that dysregulation of certain microRNAs (miRNAs) may con-tribute to tumor progression and metastasis. Previous studies have shown that miR-409-3p is dysregulated in some malignancies, but its role in bladder cancer is still unknown. Here, we find that miR-409-3p is down-regulated in human bladder cancer tissues and cell lines. Enforced expression of miR-409-3p in bladder cancer cells significantly reduced their migration and invasion without affecting cell viability. Bioinformatics analysis identified the pro-metastatic gene c-Met as a potential miR-409-3p target. Further studies indicated that miR-409-3p suppressed the expression of c-Met by binding to its 3-untranslated region. Silencing of c-Met by small interfering RNAs phenocopied the effects of miR-409-3p overexpression, whereas restoration of c-Met in bladder cancer cells bladder cancer cells overexpressing miR-409-3p, partially reversed the suppressive effects of miR-409-3p. We further showed that MMP2 and MMP9 may be downstream effector proteins of miR-409-3p. These findings indicate that miR-409-3p could be a potential tumor suppressor in bladder cancer.

MicroRNA-576-3p Inhibits Proliferation in Bladder Cancer Cells by Targeting Cyclin D1

Liping Xie,Zhen Liang,Shiqi Li,Xin Xu,Xianglai Xu,Xiao Wang,Jian Wu,Yi Zhu,Zhenghui Hu,Yiwei Lin,Yeqing Mao,Hong Chen,Jindan Luo,Ben Liu,Xiangyi Zheng 한국분자세포생물학회 2015 Molecules and cells Vol.38 No.2

MicroRNAs (miRNAs) are small, endogenous RNAs that play important gene-regulatory roles by binding to the imperfectly complementary sequences at the 3 -UTR of mRNAs and directing their gene expression. Here, we first discovered that miR-576-3p was down-regulated in human bladder cancer cell lines compared with the non-malignant cell line. To better characterize the role of miR-576-3p in bladder cancer cells, we over-expressed or down-regulated miR-576-3p in bladder cancer cells by transfecting with chemically synthesized mimic or inhibitor. The overexpression of miR-576-3p remarkably inhibited cell proliferation via G1-phase arrest, and decreased both mRNA and protein levels of cyclin D1 which played a key role in G1/S phase transition. The knock-down of miR-576-3p significantly promoted the proliferation of bladder cancer cells by accelerating the progression of cell cycle and increased the expression of cyclin D1. Moreover, the dual-luciferase reporter assays indicated that miR-576-3p could directly target cyclin D1 through binding its 3 -UTR. All the results demonstrated that miR-576-3p might be a novel suppressor of bladder cancer cell proliferation through targeting cyclin D1.