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In this study, Poly(vinyl alcohol)/cellulose nanofiber (PVA/CNF) hydrogels have been successfully prepared using γ-ray irradiation, annealing, and rehydration processes. In addition, the effects of CNF content and annealing methods on the hydrogel properties, including gel fraction, micromorphology, crystallinity, swelling behavior, and tensile and friction properties, are investigated. Consequently, the results show that at an absorbed dose of 30 kGy, the increase in CNF content increases the gel fraction, tensile strength, and elongation at break of irradiated PVA/CNF hydrogels, but decreases the water absorption. In addition, the cross-linking density of the PVA/CNF hydrogels is significantly increased at an annealing temperature of 80 °C, which leads to the transition of the cross-sectional micromorphology from porous networks to smooth planes. For the PVA/CNF hydrogel with a CNF content of 0.6%, the crystallinity increases from 19.9% to 25.8% after tensile annealing of 30% compared to the original composite hydrogel. The tensile strength is substantially increased from 65.5 kPa to 21.2 MPa, and the modulus of elasticity reaches 4.2 MPa. Furthermore, it shows an extremely low coefficient of friction (0.075), which suggests that it has the potential to be applied as a material for artificial joint cartilage. [ABSTRACT FROM AUTHOR]

With the development in the field of biomaterials, research on alternative biocompatible materials has been initiated, and alginate in polysaccharides has become one of the research hotspots due to its advantages of biocompatibility, biodegradability and low cost. In recent years, with the further understanding of microscopic molecular structure and properties of alginate, various physicochemical methods of cross-linking strategies, as well as organic and inorganic materials, have led to the development of different properties of alginate hydrogels for greatly expanded applications. In view of the potential application prospects of alginate-based hydrogels, this paper reviews the properties and preparation of alginate-based hydrogels and their major achievements in delivery carrier, dressings, tissue engineering and other applications are also summarized. In addition, the combination of alginate-based hydrogel and new technology such as 3D printing are also involved, which will contribute to further research and exploration., Competing Interests: Declaration of competing interest No conflict of interest exits in the submission of this paper., (Copyright © 2024. Published by Elsevier B.V.)

Direct mechanical coupling is known to be critical for establishing synchronization among cilia. However, the actual role of the connections is still elusive-partly because controlled experiments in living samples are challenging. Here, we employ an artificial ciliary system to address this issue. Two cilia are formed by chains of self-propelling robots and anchored to a shared base so that they are purely mechanically coupled. The system mimics biological ciliary beating but allows fine control over the beating dynamics. With different schemes of mechanical coupling, artificial cilia exhibit rich motility patterns. Particularly, their synchronous beating display two distinct modes-analogous to those observed in C. reinhardtii, the biciliated model organism for studying synchronization. Close examination suggests that the system evolves towards the most dissipative mode. Using this guideline in both simulations and experiments, we are able to direct the system into a desired state by altering the modes' respective dissipation. Our results have significant implications in understanding the synchronization of cilia.

A novel and efficient approach for the synthesis of α, β-unsaturated sulfones through heterogeneous photocatalyzed C-S coupling reactions have been developed. The use of molten-salt method derived carbon nitride (MCN), a transition metal-free polymeric photocatalyst, combined with enhanced crystallinity and potassium iodide as an additive, effectively modulates photogenerated reactive redox species, markedly increasing the overall reaction selectivity. This method achieves the shortest reaction time (2 h) with high yield (up to 95 %) among the reported heterogeneous catalytic C-S bond formation reactions, matching the efficiency of the homogeneous photocatalysts. Furthermore, the application to challenging alkyne substrates has been demonstrated, underscoring the potential for a broad range of applications in pharmaceutical research and synthetic chemistry., (© 2024 Wiley-VCH GmbH.)