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Catalytic control over molecular self‐assembly provides a powerful approach to regulate the structures as well as the functionalities of supramolecular materials. Revealing how the catalysts affect the molecular self‐assembly process is crucial for rational design and control of the supramolecular self‐assembly systems. Herein, relying on a hydrazone‐based dynamic supramolecular hydrogel system, the effects of various nucleophilic catalysts on the self‐assembly of the hydrogels are investigated, demonstrating that the catalyst influences the hydrogelators self‐assembly via facilitating both the reaction and hydrogelators nucleation processes. The catalyst with higher catalytic activity accelerates the formation thereon the self‐assembly of hydrazone‐based hydrogelators, leading to hydrogels with more branched networks and higher stiffness. Importantly, we also verify that the catalysts, depending on the molecular structure, can also accelerate the self‐assembly process by affecting the hydrogelators nucleation process. These findings not only add more details to the effects of nucleophilic catalysts on the hydrazone‐based hydrogelation system, but also suggest that both the catalysis activity and chemical structures should be considered for catalytically controlled molecular self‐assembly. [ABSTRACT FROM AUTHOR]

One of the key advantages of terahertz (THz) communication is its potential for energy efficiency, making it an attractive option for green communication systems. Coherent THz transmission technology has recently been explored in the literature. However, there exist few error performance results for such a wireless link employing coherent THz technology. In this paper, we explore a comprehensive terrestrial channel model designed for wireless line-of-sight communication using THz frequencies. The performance of coherent THz links is analyzed, and it is found to be notably affected by two significant factors, atmospheric turbulence and pointing errors. These could occur between the terahertz transmitter and receiver in terrestrial links. The exact and asymptotic solutions are derived for bit error rate and interrupt probability for binary phase-shift keying coherent THz systems, respectively, over log-normal and Gamma–Gamma turbulent channels. The asymptotic outage probability analysis is also performed. It is shown that the presented results offer a precise estimation of coherent THz transmission performance and its link budget. [ABSTRACT FROM AUTHOR]

Supramolecular self-assembly in a biological system is usually dominated by sophisticated metabolic processes (chemical reactions) such as catalysis of enzymes and consumption of high energy chemicals, leading to groups of biomolecules with unique dynamics and functions in an aqueous environment. In recent years, increasing efforts have been made to couple chemical reactions to molecular self-assembly, with the aim of creating supramolecular materials with lifelike properties and functions. In this feature article, after summarising the work of chemical reaction mediated supramolecular hydrogels, we first focus on a typical example where dynamic self-assembly of molecular hydrogels is activated by in situ formation of a hydrazone bond in water. We discuss how the formation of the hydrazone-based supramolecular hydrogels can be controlled in time and space. After that, we describe transient assembly of supramolecular hydrogels powered by out-of-equilibrium chemical reaction networks regulated by chemical fuels, which show unique properties such as finite lifetime, dynamic structures, and regenerative capabilities. Finally, we provide a perspective on the future investigations that need to be done urgently, which range from fundamental research to real-life applications of dynamic supramolecular hydrogels. [ABSTRACT FROM AUTHOR]

Phenological periods can affect the growth of forage, the single food source for grazing animals, and its nutrition and the stage of growth of the animals can affect the rumen microbiota. The aim of this study was to evaluate the effects of phenological periods (regreen vs. grassy) and growing stages (hoggets (1.5 years old) vs. rams (3 years old)) on rumen bacteria communities and functions in Alpine Merion sheep. The result showed that the Alpha diversity indices of ACE (p < 0.001), Chao (p < 0.001), and Shannon (p < 0.001) were higher in the regreen stage. At the phylum level, the abundances of Bacteroidetes (p = 0.003) and Firmicutes (p = 0.017) shifted with plant phenology. The abundance of fiber-degrading bacteria altered at the genus level (p < 0.05). Genes related to fatty acid degradation and metabolism increased in both the growing stage sheep (p < 0.05). In the grassy stage, the abundance of vitamin B6 metabolism (p = 0.046) was increased in hoggets. In summary, this study showed that the phenological stage had a significant effect on the rumen bacterial compartment and functions in two growing stages, while the growing stage only tended to change rumen bacterial diversity. [ABSTRACT FROM AUTHOR]