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Polyethylene terephthalate (PET) foam sandwich structure is widely used in the fields of construction, aerospace and shipbuilding. We have conducted research on its hygroscopic phenomenon. Take different sizes of GFRP panels, PET foam and PET foam sandwich structure for moisture absorption tests, analyze the data on the basis of the classic Fick’s law of diffusion to obtain the moisture absorption curves of each sample. And get the diffusion coefficient of the specimen. Then, we use the multi-physics software COMSOL to model and analyze the moisture absorption properties of the specified samples. The moisture absorption curve obtained by theoretical calculation was compared with the experimental moisture absorption curve, and the results showed that the two Good agreement. Tests have proved that the moisture absorption performance of PET foam is much greater than that of GFRP panel material, and the relative moisture absorption is related to the specific surface area of the sample. In the PET foam sandwich structure, the GFRP panel can effectively inhibit the hygroscopicity of the PET foam and has an excellent protective effect on the PET foam.

The diffusion influence of seawater on the static and interlayer cracking properties of a polyvinyl chloride foam sandwich structure is investigated in this study. After soaking specimens in seawater for various durations, various comparison tests are performed to investigate the effects of seawater. Compression tests for H60 and H200 polyvinyl chloride foam specimens are conducted to study strength and modulus degradation, and the results show that immerging time and temperature have significant effects on polyvinyl chloride foam properties. Tensile tests for glass-fibre-reinforced plastic panels, four-point bending tests and double cantilever bending tests for polyvinyl chloride foam sandwich specimens are also performed. The results show that seawater immerging treatment has a noticeable influence on glass-fibre-reinforced plastic tensile properties and interlayer critical energy release rate values, but has almost no effect on bending properties of foam sandwich specimen. Furthermore, a rate-dependent phenomenon is observed in double cantilever bending tests, in which higher loading rate will lead to larger critical energy release values. Numerical simulation is also performed to illustrate the cracking process of double cantilever bending tests and shows a certain accuracy. The simulation also demonstrates that the viscoelasticity of foam material after immerging treatment results in the rate-dependent characterization of double cantilever bending tests.

In order to explore the effect of MiR-122 nanoparticle (NP) drug delivery system (NPDDS) on the condition and curative effect of patients with drug-induced liver injury (DILI). The phosphate buffered saline solution was added to the solution of Monoammonium Glycyrrhizanate (MAG) NPs to make the suspension. Then, 50 μL of the MAG β-cyclodextrin star-shaped cationic polymer solution was added to the 100 μg/mL MiR-122 solution and form MAG/MiR-122 co-loaded NPs. 40 cases of acute DILI patients in hospital were selected as the research subjects. Control group, polymer group, drug-loaded group, and co-loaded group were set up, and fluorescence quantitative PCR was employed to measure the expression level of MiR-122 in the cells. The untreated DILI cells were set as control group, while the MAG/MiR-122 co-loaded NPs-treated DILI cells were set as treatment group. The treatment effects of the two groups were analyzed and compared. The results showed that the MAG/MiR co-loaded NPs prepared were of regular round shape and uniform particle size distribution. The expression of MiR-122 was low in control group, and its content in injured cells was extremely low. The expression of MiR-122 in the co-loaded group was superior to drug-loaded group. The effective rate of drug treatments in treatment group was significantly superior to control group, and the differences were substantial (P < 0.05). The number of red blood cells (RBC) of treatment group decreased notably relative to controls, while differences on white blood cells (WBC) and platelets (PLT) between two groups were not considerable (P > 0.05). In conclusion, MAG/MiR co-loaded NPs can effectively improve the therapeutic effect of DILI. Moreover, early DILI screening can be implemented by detecting the expression level of MiR-122 in the cells of DILI patients.