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676 results on '"Li, Zhiquan"'

153. Effects of Pore Size on the Osteoconductivity and Mechanical Properties of Calcium Phosphate Cement in a Rabbit Model

Author

Yaoping Wu, Liu Yanwu, Junjun Fan, Yi-Nan Zhao, Jian Liu, and Li Zhiquan

Subjects
Pore size, Chemistry, 0206 medical engineering, Biomedical Engineering, Medicine (miscellaneous), Bioengineering, 02 engineering and technology, General Medicine, 021001 nanoscience & nanotechnology, 020601 biomedical engineering, Radius bone, Biomaterials, medicine.anatomical_structure, In vivo, medicine, Rabbit model, Alkaline phosphatase, 0210 nano-technology, Porosity, Bone regeneration, Calcium phosphate cement, Biomedical engineering
Abstract

Calcium phosphate cement (CPC) porous scaffold is widely used as a suitable bone substitute to repair bone defect, but the optimal pore size is unclear yet. The current study aimed to evaluate the effect of different pore sizes on the processing of bone formation in repairing segmental bone defect of rabbits using CPC porous scaffolds. Three kinds of CPC porous scaffolds with 5 mm diameters and 12 mm length were prepared with the same porosity but different pore sizes (Group A: 200-300 µm, Group B: 300-450 µm, Group C: 450-600 µm, respectively). Twelve millimeter segmental bone defects were created in the middle of the radius bone and filled with different kinds of CPC cylindrical scaffolds. After 4, 12, and 24 weeks, alkaline phosphatase (ALP), histological assessment, and mechanical properties evaluation were performed in all three groups. After 4 weeks, ALP activity increased in all groups but was highest in Group A with smallest pore size. The new bone formation within the scaffolds was not obvious in all groups. After 12 weeks, the new bone formation within the scaffolds was obvious in each group and highest in Group A. At 24 weeks, no significant difference in new bone formation was observed among different groups. Besides the osteoconductive effect, Group A with smallest pore size also had the best mechanical properties in vivo at 12 weeks. We demonstrate that pore size has a significant effect on the osteoconductivity and mechanical properties of calcium phosphate cement porous scaffold in vivo. Small pore size favors the bone formation in the early stage and may be more suitable for repairing segmental bone defect in vivo.

Published
2016

171. Whirl flutter and rotor hub center’s motion image of tiltrotor aircraft

Author

LI ZhiQuan and Xia Pinqi

Subjects
Engineering, Wing, Computer Networks and Communications, business.industry, Rotor (electric), Nacelle, Equations of motion, Structural engineering, Rotation, Aeroelasticity, law.invention, Control and Systems Engineering, law, Fictitious force, Flutter, Aerospace engineering, business
Abstract

Based on the Johnson's model of tiltrotor aircraft with nine degrees of freedom containing the assumptions of articulated rotor, rigid nacelle, elastic wing and clamped connections between the nacelle and wing, and considering the elastic connections between the nacelle and wing, the aeroelastic model of tiltrotor aircraft with eleven degrees of freedom for analysis of the whirl flutter of rotor/nacelle and instability of wing in forward flight has been established in this paper. The influences of the nacelle pitching and swing on the rotor inertial force and Coriolis force, the gyroscopic moment produced by the nacelle motion and rotor rotation, the supporting stiffness and damping of nacelle, the influence of nacelle motion on change in inflow of rotor and the influence of nacelle motion on wing motion have been considered in establishing the equations of motion of the rotor/nacelle/ wing coupled system. By using the system parameters of experimental model, the modal frequencies and damping ratios changing with the flight speed were calculated to determine the critical instability speed of the system. By influence of change in the supporting stiffness of nacelle on the critical instability speed, the dynamic instability form of tiltrotor aircraft in forward flight such as the vertical divergence motion of wing flutter or the whirl flutter of rotor/nacelle can be determined. According to the drawn motion trajectories of rotor hub center, the motion images of rotor hub center in the conditions of whirl flutter and wing instability of tiltrotor aircraft can be revealed, intuitively describing the motion patterns of rotor hub center in occurrence of the whirl flutter.

Published
2014

172. High-Sensitivity Biosensor-Based Enhanced SPR by ZnO/MoS2 Nanowires Array Layer with Graphene Oxide Nanosheet.

Author

Guo, Shiliang, Wu, Xiaogang, Li, Zhiquan, and Tong, Kai

Subjects
GRAPHENE oxide, NANOWIRES, FINITE element method, REFRACTIVE index, ZINC oxide
Abstract

A novel SPR biosensor that can achieve a high sensitivity is proposed; therefore, a new prism coupling structure based on metal nanowires array layer is designed in this paper. The thickness of each medium layer for the structure is analyzed to obtain the optimal SPR spectrum, by the finite element method, so that the sensitivity is able to be enhanced greatly. The optimal thicknesses of each medium layer are given, and the sensitivity of the SPR biosensor can reach as high as 210.75°/RIU for the refractive index of the sensing medium, from 1.30 to 1.38. [ABSTRACT FROM AUTHOR]

Published
2020
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173. Shape‐Dependent CeO2@BiOI for Degradation of Aqueous Cr(VI).

Author

Peng, Shuaishuai, Yang, Jingxia, Guo, Lei, Wang, Jinjie, Zhao, Jiachang, Xu, Jingli, and Li, Zhiquan

Subjects
SURFACE area, HEXAVALENT chromium, PHOTOLUMINESCENCE, HETEROGENEOUS catalysis
Abstract

CeO2 with different morphologies (nanoparticles/NP, nanorods/NR, nanocubes/NC, nano‐octahedra/NO) are synthesized and decorated on BiOI nanoplates substrates to form CeO2@BiOI composites, which are used for aqueous Cr(VI) degradation. The intersurface states between BiOI and diverse CeO2 nanoparticles exhibit distinct behaviors when checked by XPS and photoluminescence intensity. The Cr(VI) degradation results show that the synthesized CeO2@BiOI nanocomposites possess higher photocatalytic activity than pure CeO2 or BiOI, and the CeO2‐NP@BiOI nanocomposite (molar ratio of CeO2: BiOI = 1:2) is the best one among them, with which the Cr(VI) is degraded up to 95.0% after 30 min irradiation using it as the photocatalyst. The superior catalytic performance of CeO2‐NP@BiOI can be attributed to a higher Ce3+ ratio of CeO2‐NP, a larger specific surface area, relatively low OH/CO32− content on the composite surface, and especially the good interaction between the CeO2 (111) facet and the BiOI surface. [ABSTRACT FROM AUTHOR]

Published
2020
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184. Evaluation of 3D structures fabricated with two-photon-photopolymerization by using FTIR spectroscopy.

Author

Cicha, Klaus, Li, Zhiquan, Stadlmann, Klaus, Ovsianikov, Aleksandr, Markut-Kohl, Ruth, Liska, Robert, and Stampfl, Jürgen

Subjects
*PHOTOPOLYMERIZATION, *FOURIER transform infrared spectroscopy, *PHOTOPOLYMERS, *MONOMERS, *PHOTONS
Abstract

Two-photon-induced photopolymerization (2PP) has gained increased interest due to the capability of manufacturing three-dimensional structures with very high feature resolution. To assess the suitability of photopolymer systems for 2PP, methods have to be developed that allow a screening of the efficiency of monomer-initiator combinations in the context of high throughput, large processing window and geometric quality of the final parts. In this paper, a method for evaluating 2PP structures is described. For this purpose, the double-bond conversion of fabricated 2PP structures was measured giving quantifiable results about the efficiency of the photoinitiator. The method is based on local measurement of the double-bond conversion of the photopolymer using a microscope in combination with infrared spectroscopy. The obtained double-bond conversion is a measure for the efficiency of the photopolymer system (initiator in combination with monomer), and thus allows to compare different photopolymers in a quantitative way. Beside this evaluation of 2PP structures, fabrication of complex 3D structures was done to determine the limits of the 2PP technology for miscellaneous components. [ABSTRACT FROM AUTHOR]

Published
2011
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185. Li, Zhiquan

Author

Li, Zhiquan and Li, Zhiquan

Published
2017

186. Honokiol induces autophagy and apoptosis of osteosarcoma through PI3K/Akt/mTOR signaling pathway

Author

Zhao Yinan, Hui Dong, Liu Yanwu, Chen Xiaochao, Minliang Ma, Li Zhiquan, Wu Yaoping, and Mo Li

Subjects
0301 basic medicine, Honokiol, Cancer Research, Apoptosis, Bone Neoplasms, Biochemistry, Lignans, 03 medical and health sciences, chemistry.chemical_compound, Phosphatidylinositol 3-Kinases, 0302 clinical medicine, Cyclin D1, Bcl-2-associated X protein, Cell Line, Tumor, Genetics, Humans, Propidium iodide, Molecular Biology, Protein kinase B, PI3K/AKT/mTOR pathway, Cell Proliferation, bcl-2-Associated X Protein, Osteosarcoma, biology, Caspase 3, TOR Serine-Threonine Kinases, Autophagy, RPTOR, Biphenyl Compounds, Antineoplastic Agents, Phytogenic, 030104 developmental biology, Oncology, chemistry, 030220 oncology & carcinogenesis, Cancer research, biology.protein, Molecular Medicine, Tumor Suppressor Protein p53, Proto-Oncogene Proteins c-akt, Signal Transduction
Abstract

Honokiol is the main active constituent of Magnolia officinalis. With effective and long‑term pharmacological functions of being antibacterial, anti‑oxidative, anti‑inflammatory, antitumor, anti‑spasmic, anti‑anxiety and anti‑viral, Honokiol is clinically used in the treatment of acute enteritis and chronic gastritis. The aim of the present study was to observe the possible anti‑effects of honokiol on autophagy and apoptosis of osteosarcoma, and to investigate the role of the PI3K/Akt/mTOR signaling pathway in its anticancer effects. MTT assay was used to evaluate cell proliferation and Annexin V‑fluorescein isothiocyanate/propidium iodide staining flow cytometry was used to analyze the apoptotic rate. The authors identified that honokiol could inhibit cell proliferation and induce the apoptotic rate of osteosarcoma cells. The expression level of Bcl‑2‑like protein 4, caspase‑3 and p53 protein expression were induced and cyclin D1 protein expression was suppressed in osteosarcoma cells by honokiol. Autophagy‑associated LC3II protein expression level was promoted, and PI3K, p‑Akt and p‑mTOR protein expression level was suppressed in osteosarcoma cells by honokiol. The present study demonstrated, to the best of the authors' knowledge, for the first time that honokiol induces autophagy and apoptosis of osteosarcoma cells through the PI3K/Akt/mTOR signaling pathway.

Published
2016

187. Graphene Surface Plasmon Polaritons Based Photoelectric Modulator with Double Branched Structure

Author

Yue Zhong, Liu Tonglei, Feng Dandan, Li Xin, Bai Lan-Di, Gu Erdan, and Li Zhiquan

Subjects
Materials science, business.industry, Graphene, Photoelectric effect, 01 natural sciences, Surface plasmon polariton, Atomic and Molecular Physics, and Optics, 010305 fluids & plasmas, Electronic, Optical and Magnetic Materials, law.invention, law, 0103 physical sciences, Optoelectronics, 010306 general physics, business
Published
2018

191. Comparison of Two Rabbit Models with Deficiency of Corneal Epithelium and Limbal Stem Cells Established by Different Methods

Author

Zhang, Hening, primary, Lin, Shaochun, additional, Zhang, Min, additional, Li, Qijiong, additional, Li, Weihua, additional, Wang, Wencong, additional, Zhao, Minglei, additional, Xie, Yaojue, additional, Li, Zhiquan, additional, Huang, Mian, additional, Wang, Zhichong, additional, Zhang, Xiulan, additional, and Huang, Bing, additional

Published
2017
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