Non-linear FEA of mechanical properties of modular prefabricated steel-concrete composite joints

Wu Cheng Long,Kan Jian Cheng,Liu Ji Ming,Mou Ben 국제구조공학회 2021 Steel and Composite Structures, An International J Vol.40 No.4

This paper study the seismic performance of modular prefabricated SRC column to steel beam composite joint (MPCJ) under static loading. Numerical modeling of MPCJs with three different beam-end connections was carried out in ABAQUS. Results of the numerical calculation were compared with existing quasi-static test results to verify the feasibility of the numerical model. The model was then used to analyze changes in the moment-rotation relation, failure mode, ductility, stiffness, and bolt stress in the joint between the column and joint module. Besides, stress distributions in the joints were analyzed along different stress paths. Under monotonic loading, the mechanical performance of the MPCJ is significantly affected by the beam end connection mode. Failure of the MPCJ mainly occurs at the beam end connection, thus, the aim of keeping the plastic hinge away from the joint core and preventing shear failure is achieved. Furthermore, the maximum story drift ratio is 3.9–5 times greater than the recommended limit, which indicates good ductility and deformation performance. The MPCJ of the three-beam end connection methods is all semi-rigid connections. The beam end structure will have a large influence on the bolt tension and stress distribution. According to the test research results, a nonlinear model with three parameters including joint cover plate cantilever section length, flange connecting plate thickness and flange connecting plate weld length was established. The theoretical calculation results was consistent with the results of the numerical simulation. MPCJs can be designed based on the proposed theoretical calculation formula.

FEM analysis of the modular prefabricated steel-concrete composite beam-column internal joint under reciprocating action

Cheng Long Wu,Jian Cheng Kan,Qi Hui Wang,Ji Ming Liu,Zun Qiang Li 국제구조공학회 2021 Steel and Composite Structures, An International J Vol.41 No.1

Prefabricated steel-concrete composite structure has the advantages of large bearing capacity, reliable connection, and good durability, which is of great significance to the development of building industrialization. In this paper, a finite element model (FEM) of the modular prefabricated SRC column-steel beam composite joint is established and verified its accuracy through ABAQUS. The effects of various parameter variables on the hysteresis curve, skeleton curve, ductility, energy consumption, and performance deterioration are investigated. The results show that as the axial compression ratio increases, the joint bearing capacity first increases and then decreases, the strength and stiffness have relatively stable degradation characteristics. However, the hysteresis curve has a certain “pinch” phenomenon, which reduces the energy consumption performance. Different column end bolts margin and apertures have little effect on the bearing capacity, strength and stiffness degradation performance, but affect energy consumption and ductility. The width-to-thickness ratio of the square steel tube has a greater impact on the bearing capacity, energy consumption and ductility, and has less impact on the strength and stiffness degradation performance. As the thickness of the joint cover plate increases, the bearing capacity, energy consumption and initial stiffness of the joint gradually increase, the ductility first increases and then decreases.

ATP6V0d2 Suppresses Alveoli Macrophage Alternative Polarization and Allergic Asthma via Degradation of PU.1

Liu Na,Feng Yuchen,Liu Huicheng,Wu Wenliang,Liang Yuxia,Li Pingfei,Wei Zhengping,Wu Min,Tang Zhao-Hui,Han Junyan,Cheng Xiang,Liu Zheng,Laurence Arian,Li Huabin,Zhen Guohua,Yang Xiang-Ping 대한천식알레르기학회 2021 Allergy, Asthma & Immunology Research Vol.13 No.3

Purpose Macrophages are important regulators of environmental allergen-induced airway inflammation and asthma. ATP6V0d2 is a subunit of vacuolar ATPase highly expressed in macrophages. However, the functions of ATP6V0d2 in the regulation of pathogenesis of allergic asthma remain unclear. The aim of this study is to determine the function and related molecular mechanisms of macrophage protein ATP6V0d2 in allergic asthma. Methods We compared the disease severity between female C57BL/6 wild-type and ATP6V0d2−/− mice in an ovalbumin (OVA)-induced asthma model. We also investigated the association of expression of ATP6V0d2, PU.1 and CCL17 with disease severity among asthmatic patients. Results The expression of ATP6V0d2 in sputum cells of asthmatic patients and in the lungs of OVA-challenged mice was enhanced compared to healthy subjects and their counterparts, respectively. However, ATP6V0d2-deficient mice exaggerated inflammatory cell infiltration as well as enhanced alternative activated macrophage (AAM) polarization and mucus production in an OVA-induced asthma model. Furthermore, we found that Atp6v0d2 promoted lysosomal degradation of Pu.1, which induced AAM polarization and Ccl17 production. Among asthma patients, ATP6V0d2 expression was inversely associated with disease severity, whereas PU.1 and CCL17 expression was positively associated with disease severity. Conclusions Our results identify macrophage Atp6v0d2, as an induced feedback inhibitor of asthma disease severity by promoting Pu.1 lysosomal degradation, which may in turn leads to reduced AAM polarization and Ccl17 production.

Applications of Bacterial Cellulose-Based Composite Materials in Hard Tissue Regenerative Medicine

Liu Yingyu,Liu Haiyan,Guo Susu,Qi Jin,Zhang Ran,Liu Xiaoming,Sun Lingxiang,Zong Mingrui,Cheng Huaiyi,Wu Xiuping,Shanxi Medical University School and Hospital of Stomatology 한국조직공학과 재생의학회 2023 조직공학과 재생의학 Vol.20 No.7

BACKGROUND: Cartilage, bone, and teeth, as the three primary hard tissues in the human body, have a significant application value in maintaining physical and mental health. Since the development of bacterial cellulose-based composite materials with excellent biomechanical strength and good biocompatibility, bacterial cellulose-based composites have been widely studied in hard tissue regenerative medicine. This paper provides an overview of the advantages of bacterial cellulose-based for hard tissue regeneration and reviews the recent progress in the preparation and research of bacterial cellulose-based composites in maxillofacial cartilage, dentistry, and bone. METHOD: A systematic review was performed by searching the PubMed and Web of Science databases using selected keywords and Medical Subject Headings search terms. RESULTS: Ideal hard tissue regenerative medicine materials should be biocompatible, biodegradable, non-toxic, easy to use, and not burdensome to the human body; In addition, they should have good plasticity and processability and can be prepared into materials of different shapes; In addition, it should have good biological activity, promoting cell proliferation and regeneration. Bacterial cellulose materials have corresponding advantages and disadvantages due to their inherent properties. However, after being combined with other materials (natural/ synthetic materials) to form composite materials, they basically meet the requirements of hard tissue regenerative medicine materials. We believe that it is worth being widely promoted in clinical applications in the future. CONCLUSION: Bacterial cellulose-based composites hold great promise for clinical applications in hard tissue engineering. However, there are still several challenges that need to be addressed. Further research is needed to incorporate multiple disciplines and advance biological tissue engineering techniques. By enhancing the adhesion of materials to osteoblasts, providing cell stress stimulation through materials, and introducing controlled release systems into matrix materials, the practical application of bacterial cellulose-based composites in clinical settings will become more feasible in the near future.

NOX4/Src regulates ANP secretion through activating ERK1/2 and Akt/GATA4 signaling in beating rat hypoxic atria

Wu, Cheng-zhe,Li, Xiang,Hong, Lan,Han, Zhuo-na,Liu, Ying,Wei, Cheng-xi,Cui, Xun The Korean Society of Pharmacology 2021 The Korean Journal of Physiology & Pharmacology Vol.25 No.2

Nicotinamide adenine dinucleotide phosphate oxidases (NOXs) are the major enzymatic source of reactive oxygen species (ROS). NOX2 and NOX4 are expressed in the heart but its role in hypoxia-induced atrial natriuretic peptide (ANP) secretion is unclear. This study investigated the effect of NOX on ANP secretion induced by hypoxia in isolated beating rat atria. The results showed that hypoxia significantly upregulated NOX4 but not NOX2 expression, which was completely abolished by endothelin-1 (ET-1) type A and B receptor antagonists BQ123 (0.3 μM) and BQ788 (0.3 μM). ET-1-upregulated NOX4 expression was also blocked by antagonists of secreted phospholipase A2 (sPLA2; varespladib, 5.0 μM) and cytosolic PLA2 (cPLA2; CAY10650, 120.0 nM), and ET-1-induced cPLA2 expression was inhibited by varespladib under normoxia. Moreover, hypoxia-increased ANP secretion was evidently attenuated by the NOX4 antagonist GLX351322 (35.0 μM) and inhibitor of ROS N-Acetyl-D-cysteine (NAC, 15.0 mM), and hypoxia-increased production of ROS was blocked by GLX351322. In addition, hypoxia markedly upregulated Src expression, which was blocked by ET receptors, NOX4, and ROS antagonists. ET-1-increased Src expression was also inhibited by NAC under normoxia. Furthermore, hypoxia-activated extracellular signal-regulated kinase 1/2 (ERK1/2) and protein kinase B (Akt) were completely abolished by Src inhibitor 1 (1.0 μM), and hypoxia-increased GATA4 was inhibited by the ERK1/2 and Akt antagonists PD98059 (10.0 μM) and LY294002 (10.0 μM), respectively. However, hypoxia-induced ANP secretion was substantially inhibited by Src inhibitor. These results indicate that NOX4/Src modulated by ET-1 regulates ANP secretion by activating ERK1/2 and Akt/GATA4 signaling in isolated beating rat hypoxic atria.

Seroprevalence of Toxoplasma gondii Infection in Police Dogs in Shenyang, Northeastern China

Cheng-Wu Liu,Na Yang,Jian-Bin He,Ming-Yang Mu,Min Yang,Ning Sun,Hong-Kui Li 대한기생충학열대의학회 2013 The Korean Journal of Parasitology Vol.51 No.5

A new power supply strategy for high power rectifying units in electrolytic copper process

Liu He-Miao,Zhao Yu-Lian,Cheng Yan-Ming,Wu Jing,Al Shurafa Mahmoud A. M.,Liu Cheng,Lee Il-Kyoo 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.2

For achieving the minimum energy consumption in electrolytic copper process, this paper proposes a power supply optimization strategy based on the improved BP neural network for high-power electrolytic copper rectifying units to eff ectively improve the utilization rate of electric energy, reduce the production cost, and achieve high effi ciency and energy saving. Aiming to operation scenarios including normal operation of rectifi ers, fault of random one rectifi er, fault of random two rectifi ers and number change of electrolytic tanks, the output current of each rectifi er, transformer gears and control angle of thyristor are obtained under these four scenarios by the proposed power supply strategy. The simulation results indicate that compared with BP neural network and PSO optimizing BP(PSO-BP)neural network, the prediction error of power supply strategy of GA optimizing BP (GA-BP) neural network is the minimum. Consequently, the optimal control of the output current of each rectifi er is obtained by using GA-BP neural network, and the stabilized current precision of total output current can be kept at 0.003–0.005, which verifi es the eff ectivity and feasibility of the proposed power supply optimization strategy, which provides valuable guidance and reference for the future design of high-power power supply system in electrolytic copper or other electrolytic metals.

Research on the Matthews Correlation Coefficients Metrics of Personalized Recommendation Algorithm Evaluation

Yingbo Liu,Jiujun Cheng,Chendan Yan,Xiao Wu,Fuzhen Chen 보안공학연구지원센터 2015 International Journal of Hybrid Information Techno Vol.8 No.1

The personalized recommendation systems could better improve the personalized service for network user and alleviate the problem of information overload in the Internet. As we all know, the key point of being a successful recommendation system is the performance of recommendation algorithm. When scholars put forward some new recommendation algorithms, they claim that the new algorithms have been improved in some respects, better than previous algorithm. So we need some evaluation metrics to evaluate the algorithm performance. Due to the scholar didn’t fully understand the evaluation mechanism of recommendation algorithms. They mainly emphasized some specific evaluation metrics like Accuracy, Diversity. What’s more, the academia did not establish a complete and unified assessment of recommendation algorithms evaluation system which is credibility to do the work of recommendation evaluation. So how to do this work objective and reasonable is still a challengeable task. In this article, we discussed the present evaluation metrics with its respective advantages and disadvantages. Then, we put forward to use the Matthews Correlation Coefficient to evaluate the recommendation algorithm’s performance. All this based on an open source projects called mahout which provides a rich set of components to construct the classic recommendation algorithm. The results of the experiments show that the applicability of Matthews correlation coefficient in the relative evaluation work of recommendation algorithm.

Plasma D-dimer Can Effectively Predict the Prospective Occurrence of Ascites in Advanced Schistosomiasis Japonica Patients

Xiaoying Wu,Jianwei Ren,Zulu Gao,Yun Xu,Huiqun Xie,Tingfang Li,Yanhua Cheng,Fei Hu,Hongyun Liu,Zhihong Gong,Jinyi Liang,Jia Shen,Zhen Liu,Feng Wu,Xi Sun,Zhongzheng Niu,An Ning 대한기생충학열대의학회 2017 The Korean Journal of Parasitology Vol.55 No.2

A Back Propagation Neural Network with Double Learning Rate for PID Controller in Phase-Shifted Full-Bridge Soft-switching Power Supply

Yan-Ming Cheng,Cheng Liu,Jing Wu,He-Miao Liu,Il-Kyoo Lee,Jing Niu,조주필,구경완,Min-Woo Lee,우덕근 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.6

This paper mainly focuses on the control strategy for phase-shifting full-bridge soft switching electrolytic silver power supply based on Zero Voltage Switching (ZVS) soft switching technology. Taking into consideration the low performance of traditional PID control for phase-shifting full-bridge soft-switching, this paper introduce a PID improved by Back Propagation (BP) neural network with one single learning rate which is used to calculate weights from the input layer to the hidden layer and weights from the hidden layer to the output layer. After testing, it is found that setting independent learning rate for calculation of weights from the input layer to the hidden layer and weights from the hidden layer to the output layer which will not have an adverse eff ect on the design of the controller. Instead, the learning rate can be set according to the respective characteristics of the weights between the two layers, which is called double learning rate BP neural network PID. The simulation results indicate that compared with the single learning rate BP neural network PID control, the double learning rate BP neural network control has higher response speed, less over-shoot, short time to enter the steady state and strong immunity.