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Engineering advanced cellulosics for enhanced triboelectric performance using biomanufactured proteins
Biological polymers, such as polysaccharides and polypeptides, offer renewable and biodegradable solutions for a more sustainable future. These polymers comprise natural building blocks, such as amino acids and glycans, which ensure their true environmental benefits at the end of their lifecycle. For example, cellulose is a highly sustainable material with many excellent properties, including renewability, biodegradability, and versatility in its functionality. It can be used in various forms, such as textiles, packaging materials, and building insulation. Here, we studied advanced cellulosic materials produced by blending or creating bi-composites with biomanufactured proteins inspired by squid ring teeth (SRT). Biomanufactured proteins can be synthesized in larger quantities, have a controlled production process, be modified to create desirable variants, and their production can be scaled up or down. Specifically, we engineered recombinant SRT proteins to have high electrostatic charge, induce crystallinity, and provide polar hydroxyl groups, which enhances cellulosic materials’ triboelectric response. The triboelectric voltage of blend triacetate and cellulose fibers increased by 72–108% and 49–57%, respectively, with a protein content of 10% wt. Furthermore, coating proteins on cellulosic fibers to create bi-composite fibers is a highly effective method for doubling (200%) the triboelectric performance. This finding has important implications for developing sustainable triboelectric materials and producing advanced materials using biomanufacturing.
Identification, deterioration, and protection of organic cultural heritages from a modern perspective
Organic substances such as fibroin, collagen, and cellulose are vital components of organic cultural heritages, carrying significant ancient cultural information. However, their sensitivity to environmental factors leads to heritage deterioration and reduction of values. This review briefly introduces the composition of several major organic cultural heritages (silk fabrics, leather, parchment, paper, and wood), focusing on their multilayer structure of the molecules. All aspects of organic heritages are evaluated from surface to interior using modern analytical techniques. Furthermore, the review covers the different deterioration mechanisms of organic cultural heritages by temperature, humidity, light, air pollutants, and microorganisms. Hydrolysis and oxidation are the main deterioration formats during all types of cultural heritages. The original degradation of silk fabrics and paper took place in the amorphous region, while both the crystalline and amorphous regions are destroyed as aging progresses. Compared to silk fabrics, leather and parchment are more prone to suffer bio-deterioration due to the weakness of the covalent bonds between the tanning agent and collagen. Compared to traditional contact conservation methods, contactless methods provide protection while avoiding damage to the fragile and precious organic heritages, which promotes the development of biopolymer-based composites as a promising alternative. In conclusion, it describes potential challenges and prospects for the appropriate conservation of organic cultural heritages. The comprehensive exploration of organic cultural heritages from a modern perspective is expected to promote its preservation and the transmission of history and culture.
Experimental observation of gapped shear waves and liquid-like to gas-like dynamical crossover in active granular matter
Unlike crystalline solids, liquids lack long-range order, resulting in diffusive shear fluctuations rather than propagating waves. Simulations predict that liquids exhibit a k-gap in wave-vector space, where solid-like transverse waves reappear above this gap. Experimental evidence in classical liquids has been limited, observed only in 2D dusty plasmas. Here, we investigate this phenomenon using active Brownian vibrators and uncover distinct gas-like and liquid-like phases depending on the packing fraction. We measure key properties, including pair correlation functions, mean square displacements, velocity auto-correlation functions, and vibrational density of states. In the liquid-like phase, we confirm the k-gap in transverse excitations, whose size grows as the packing fraction decreases and eventually disappears in the gas phase. Our findings extend the concept of the k-gap to active granular systems and reveal striking parallels with supercritical fluids.
Fully degradable, transparent, and flexible photodetectors using ZnO nanowires and PEDOT:PSS based nanofibres
Transparent light detection devices are attractive for emerging see-through applications such as augmented reality, smart windows and optical communications using light fidelity (Li-Fi). Herein, we present flexible and transparent photodetectors (PDs) using conductive poly(3,4-ethylenedioxythiophene): polystyrene sulfonate (PEDOT:PSS): Ag nanowires (NWs) based nanofibres and zinc oxide (ZnO) NWs on a transparent and degradable cellulose acetate (CA) substrate. The electrospun (PEDOT:PSS): Ag NW-based nanofibres exhibit a sheet resistance of 11 Ω/sq and optical transmittance of 79% (at 550 nm of wavelength). The PDs comprise of ZnO NWs, as photosensitive materials, bridging the electrode based on conductive nanofibres on CA substrate. The developed PDs exhibit high responsivity (1.10 ×106 A/W) and show excellent stability under dynamic exposure to ultraviolet (UV) light, and on both flat and curved surfaces. The eco-friendly PDs present here can degrade naturally at the end of life – thus offering an electronic waste-free solution for transparent electrodes and flexible optoelectronics applications.
Non-invasive in vivo imaging of changes in Collagen III turnover in myocardial fibrosis
Heart failure (HF) affects 64 million people globally with enormous societal and healthcare costs. Myocardial fibrosis, characterised by changes in collagen content drives HF. Despite evidence that collagen type III (COL3) content changes during myocardial fibrosis, in vivo imaging of COL3 has not been achieved. Here, we discovered the first imaging probe that binds to COL3 with high affinity and specificity, by screening candidate peptide-based probes. Characterisation of the probe showed favourable magnetic and biodistribution properties. The probe’s potential for in vivo molecular cardiac magnetic resonance imaging was evaluated in a murine model of myocardial infarction. Using the new probe, we were able to map and quantify, previously undetectable, spatiotemporal changes in COL3 after myocardial infarction and monitor response to treatment. This innovative probe provides a promising tool to non-invasively study the unexplored roles of COL3 in cardiac fibrosis and other cardiovascular conditions marked by changes in COL3.
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