Schisantherin A Improves Learning and Memory of Mice with D-Galactose-Induced Learning and Memory Impairment Through Its Antioxidation and Regulation of p19/p53/p21/ Cyclin D1/CDK4/RB Gene Expressions

Cong Liu,Weijing Sun,Ning Li,Jiaqi Gao,Chunyan Yu,Chunmei Wang,Jinghui Sun,Shu Jing,JianGuang Chen,He Li 한국식품영양과학회 2018 Journal of medicinal food Vol.21 No.7

Schisantherin A (SCA) was evaluated for possible function in restoring the learning and memory impairment induced by D-galactose in mice. ICR mice were treated with D-galactose subcutaneously (220 mg·kg−1), and followed by SCA in different doses (1.25, 2.50 and 5.00 mg·kg−1, administered orally) for 42 days. Effects of SCA on learning and memory were examined by step-through tests and Morris water maze tests. The activity of superoxide dismutase (SOD), the content of malondialdehyde (MDA) in the peripheral blood and hippocampus of mice were assayed by water-soluble tetrazolium-1 (WST-1) and thiobarbituric acid (TBA) methods. The contents of 8 hydroxy deoxy guanosine (8-OHdG) in the hippocampus of mice were detected by immunosorbent assay methods, respectively. Quantitative real-time PCR and Western Blot were respectively used to detect the expression of p19, p53, p21, cyclin D1, CDK4 and RB genes, and the phosphorylation of RB in the hippocampus of mice. We found that SCA significantly improved the learning and memory impairment induced by D-galactose in mice. After SCA treatment, SOD activity was increased and the content of MDA was decreased in both peripheral blood and hippocampus of mice. 8-OHDG content was also decreased in the hippocampus of mice. Furthermore, the expression of p19, p53 and p21 genes was reduced and the expression of cyclin D1 and CDK4 and the phosphorylation of RB protein were elevated in the hippocampus. SCA may improve the learning and memory impairment induced by D-galactose by enhancing the antioxidant capacity, and regulating the expression of p19/p53/p21/cyclinD1/CDK4 genes, and the phosphorylation of RB protein in the hippocampus of mice.

Numerical analysis of stress wave of projectile impact composite laminate

Zhangxin Guo,Weijing Niu,Junjie Cui,Gin Boay Chai,Yongcun Li,Xiaodong Wu 국제구조공학회 2023 Structural Engineering and Mechanics, An Int'l Jou Vol.87 No.2

The three-dimensional Hashin criterion and user subroutine VUMAT were used to simulate the damage in the composite layer, and the secondary stress criterion was used to simulate the interlayer failure of the cohesive element of the bonding layer and the propagation characteristics under the layer. The results showed that when the shear stress wave (shear wave) propagates on the surface of the laminate, the stress wave attenuation along the fiber strength direction is small, and thus producing a large stress profile. When the compressive stress wave (longitudinal wave) is transmitted between the layers, it is reflected immediately instead of being transmitted immediately. This phenomenon occurs only when the energy has accumulated to a certain degree between the layers. The transmission of longitudinal waves is related to the thickness and the layer orientation. Along the symmetry across the thickness direction, the greater is the stress amplitude along the layer direction. Based on the detailed investigation on the impact on various laminated composites carried out in this paper, the propagation characteristics of stress waves, the damage and the destruction of laminates can be explained from the perspective of stress waves and a reasonable layering sequence of the composite can be designed against damage and failure from low velocity impact.

The microstructure and corrosion resistance of micro-arc oxidation coatings on SiCp/A356 composites

Shihai Cui,Jianmin Han,Weijing Li,강석봉,이정무 한양대학교 세라믹연구소 2006 Journal of Ceramic Processing Research Vol.7 No.4

Micro-arc oxidation (MAO) coatings were prepared on a SiCp/A356 composite. The microstructure and phase composition of the coatings on the SiCp/A356 composite were examined by XRD and SEM methods. It was found that there were two layers in the coating, a dense layer which was mainly composed of crystalline α-Al2O3 and a loose layer which consisted of γ-Al2O3 and mullite. The coating was well bonded to the SiCp/A356 substrate. The corrosion behavior of the coated and uncoated SiCp/ A356 composites was evaluated with a salt spray test and a potentiodynamic polarization technique. The results of the salt spray test showed that the coating could improve the corrosion resistance of SiCp/A356 by 11 times. The corrosion potential was shifted significantly in the anodic direction and the corrosion current density of the coated SiCp/A356 composite was reduced.

Porous Nano-Ni/Graphene/Loofah Composites for Electromagnetic Interference Shielding

Yi Jiang,Mingwei Liang,Weijing Wang,Xuefei Lai,Kenan Xie,Li Liao,Qin Long 한국정밀공학회 2022 International Journal of Precision Engineering and Vol.9 No.4

The urgent requirement of materials with superior electromagnetic shielding properties has been aroused for alleviating electromagnetic pollution. Now, some natural materials such as silkworm cocoon, walnut shell, and so on are gradually used to prepare the electromagnetic interference shielding composites. However, loofah sponges with unique and inherent 3D hierarchical porous structure, which could be obtained from food waste and the wilted loofah, are ignored. In this work, loofah sponges were modified by NaOH and H2 O2 . Then the carbonized modified Loofah/Ni nanoparticles/Graphene composites were prepared by immersion and thermal reduction. Meanwhile, the composites had inherited advantages from natural materials such as low density, porous structure and eco-friendly. As the result of loading of Ni nanoparticles and graphene on the loofah, the outstanding performance was achieved that the shielding effectiveness was raised to 57 dB, and the specific shielding effectiveness was raised to 616.8 dB cm 3 /g. This result demonstrated that composites materials based on natural loofah sponges show tremendous potential for electromagnetic shielding.

Research on the method for producing complex SiCP/Al composite disk brake castings

Han Jianmin,Sha Zhensong,Li Weijing,Cui Shihai,Wang Jinhua 한양대학교 세라믹연구소 2006 Journal of Ceramic Processing Research Vol.7 No.4

The casting properties of a SiCP/Al composite are analyzed in this paper and the methods for producing complex castings of SiCP/Al composite disk brake together with their difficulty are discussed. An adjustable vacuum pressure casting method is established on the basis of a normal adjustable pressure casting method. The SiCP/Al composite disk brake casting is made with the established method. The results show that the adjustable vacuum pressure casting is a successful casting method for producing SiCP/Al composite castings of large dimensions and complex structures, which gives few defects as confirmed by Xray real- time image system. The casting properties of a SiCP/Al composite are analyzed in this paper and the methods for producing complex castings of SiCP/Al composite disk brake together with their difficulty are discussed. An adjustable vacuum pressure casting method is established on the basis of a normal adjustable pressure casting method. The SiCP/Al composite disk brake casting is made with the established method. The results show that the adjustable vacuum pressure casting is a successful casting method for producing SiCP/Al composite castings of large dimensions and complex structures, which gives few defects as confirmed by Xray real- time image system.

A study of the corrosion resistance of a micro-arc oxidation coating on a cast aluminum-copper alloy

Shihai Cui,Jianmin Han,Weijing Li,Xiangyang Xu,Yuanfu Liu 한양대학교 세라믹연구소 2006 Journal of Ceramic Processing Research Vol.7 No.4

Protective coatings have been successfully prepared on a high strength aluminum-copper alloy ZL205 using a micro-arc oxidation (MAO) method. The influence of the oxidation time and current density on the thickness and corrosion resistance of MAO coatings has been studied. The thickness of MAO coating increases linearly with an increase of oxidation time. When the oxidation time is shorter than 20 minutes, the coating improves the corrosion resistance of ZL205 alloy quickly with an increase of oxidation time, which is confirmed by 5% salt spray test. When the oxidation time is longer than 20 minutes, the corrosion resistance of the MAO coating increases slowly with an increase of oxidation time. For a fixed oxidation time, the thickness of the MAO coating increases with an increase of current density and the corrosion resistance can also be improved. SEM and XRD analysis show that the surface morphology and phase of the MAO coating change with an increase of the oxidation time, which results in different corrosion resistance of the MAO coating. Protective coatings have been successfully prepared on a high strength aluminum-copper alloy ZL205 using a micro-arc oxidation (MAO) method. The influence of the oxidation time and current density on the thickness and corrosion resistance of MAO coatings has been studied. The thickness of MAO coating increases linearly with an increase of oxidation time. When the oxidation time is shorter than 20 minutes, the coating improves the corrosion resistance of ZL205 alloy quickly with an increase of oxidation time, which is confirmed by 5% salt spray test. When the oxidation time is longer than 20 minutes, the corrosion resistance of the MAO coating increases slowly with an increase of oxidation time. For a fixed oxidation time, the thickness of the MAO coating increases with an increase of current density and the corrosion resistance can also be improved. SEM and XRD analysis show that the surface morphology and phase of the MAO coating change with an increase of the oxidation time, which results in different corrosion resistance of the MAO coating.

Impact of Size on Humidity Sensing Property of Copper Oxide Nanoparticles

Yang Gu,Huina Jiang,Zi Ye,Ning Sun,Xuliang Kuang,Weijing Liu,Gaofang Li,Xiaojun Song,Lei Zhang,Wei Bai,Xiaodong Tang 대한금속·재료학회 2020 ELECTRONIC MATERIALS LETTERS Vol.16 No.1

Three sizes of CuO nanosheets were synthesized by hydrothermal method. The structure and morphology of CuO nanosheets were characterized by X-ray difraction and scanning electron microscopy. Dielectrophoresis nano-manipulation technique was employed to arrange the materials on pre-designed Ti/Au electrodes to fabricate the three humidity sensors, and the sensing properties were then tested. The experimental results show that the sensitivity greatly increases with the decreasing size of CuO nanosheets, the sensitivity of sensor a, b, c are 369%, 3278%, 22,611% in 97.3% RH, respectively. The smaller sized CuO nanomaterials have better response characteristic, the response time of sensor a, b, c under 11.3–97.3% RH are 53 s, 49 s, 32 s, respectively. And correspondingly, hysteresis properties and the repeatability are also a little infuenced. In addition, based on complex impedance spectroscopy and multilayer adsorption theory, the impact of size on humidity sensing property was discussed. The results indicated the feasibility to obtain higher performance of humidity sensor, especially the higher sensitivity, via employment the smaller size sensing nanomaterials.