Poly (vinyl alcohol) (PVA) hydrogels are considered promising artificial articular cartilage. However, the weak attachment between PVA hydrogels and subchondral bone limit its application in the biomedical field. In this article, we present a new method to improve the mineralization of PVA hydrogels, and fabricate PVA hydrogels with continuously graded hydroxyapatite coating. The surface of the hydrogels was modified by dopamine self-polymerization and alendronate conjugation subsequently. Based on these, we used simulated body fluids to mineralize the hydrogels to mimic calcified cartilage zone. The modified surface of the PVA hydrogels showed excellent mineralization ability with continuously graded hydroxyapatite (HA). As the main component of human bones, HA can be chemically bonded body tissue on the interface, showing great biological activity. With the content of HA increasing, the cell adhesion ability of the hydrogels was enhanced, which helped the hydrogels integrate tightly with subchondral bone. These results demonstrate that the modified hydrogels could be promising substitutes for articular cartilage.

In order to study the performance of asphalt mixture with PR.S, Marshall test and rutting, low temperature bending, water stability test were done. The results indicated that the additive PR.S played an important role in improving high-temperature anti-rutting performance of asphalt mixture because of the cementation, reinforcement, inter-lock and adsorption function. With the amount of PR.S increasing, high-temperature performance of asphalt mixture increased gradually and low-temperature performance declined a little. In order to decide the appropriate amount of the additive PR.S, the low-temperature anti-cracking performance should be mainly considered when asphalt mixture was designed. The other performance of asphalt mixture with the amount of 0.45% PR.S could also meet the requirements of the specification. Considering its great contribution to anti-rutting, PR.S asphalt mixture was more properly adopted in the middle layer of asphalt pavement.

Knowledge of the bio-macromolecules adsorption on polylactide (PLA) was essential to the application of PLA-based biomedical materials. This study presented the adsorption behavior of type I collagen on control (CH3-enriched) and modified (introduced COOH– and CONH2– respectively) PLA surfaces by quartz crystal microbalance with energy dissipation measurements (QCM-D) and atomic force microscopy (AFM). The results showed that the Langmuir adsorption isotherms were obtained, indicating a monomolecular layer adsorption of collagen on PLA coatings. Adsorption of collagen could reach equilibrium more quickly on the modified surfaces than on the control. Large amounts of collagen (1522.2 ng·cm−2) was assembled tightly on the COOH-enriched surface of PLA, owing to the electrostatic attracting. However it was inhibited on the CONH2-enriched surface because of its increasing hydrophilicity. A netlike structure was formed on the control and COOH-enriched surfaces, while only a few of braching fibril was found on the CONH2-enriched surface. The behaviour of protein adsorption on the surfaces with different groups might effect the next stage of cell adhesion on scaffold.

Dynamic social networks also suffer from privacy violation due to the continuous release of data. In order to defend against enemy attacks, a new dynamic privacy-preserving method is innovated, called Dynamic k w Re-Structured Diversity Anonymity ( k w -SDA). This method limits the probability of disclosure of node/community identities to 1 / k when data are continuously published by protecting individuals in groups. The graph based on the previous w − 1 is released, missing some graph alterations. The advantage of the proposed method is to save many features of the network while protecting privacy efficiently and effectively.

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