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Bacterial infections can significantly impede wound healing and pose a serious threat to the patient’s life. The excessive use of antibiotics to combat bacterial infections has led to the emergence of multi-drug-resistant bacteria. Therefore, there is a pressing need for alternative approaches, such as photothermal therapy (PTT), to address this issue. In this study, for the first time, CuS NPs with photothermal properties were synthesized using sericin as a biological template, named CuS@Ser NPs. This method is simple, green, and does not produce toxic and harmful by-products. These nanoparticles were incorporated into a mixture (XK) of xanthan gum and konjac glucomannan (KGM) to obtain XK/CuS NPs composite hydrogel, which could overcome the limitations of current wound dressings. The composite hydrogel exhibited excellent mechanical flexibility, photothermal response, and biocompatibility. It also demonstrated potent antibacterial properties against both Gram-positive and negative bacteria via antibacterial experiments and accelerated wound healing in animal models. Additionally, it is proved that the hydrogel promoted tissue regeneration by stimulating collagen deposition, angiogenesis, and reducing inflammation. In summary, the XK/CuS NPs composite hydrogel presents a promising alternative for the clinical management of infected wounds, offering a new approach to promote infected wound healing.

Biomass valorization is a way to promote the ‘waste-to-wealth’ concept, which is a pre-requisite condition for a future sustainable lifestyle. The direct utilization of natural polymer for value-added materials should be prioritized. With this object, we demonstrate a facile and economical method to prepare chitin-derived supramolecular nanowires-stabilized single-atom sites Pt catalysts (SS-Pt-CSNs). A comprehensive characterization shows the structure of single-atom Pt coordinated with the organic supramolecular (ligand-type) entity, which is both flexible (like in homogenous catalyst) and robust (like in heterogenous catalyst). Such hybrid characteristics of these SS-Pt-CSNs materials exhibit excellent catalytic performance for chemo-selective hydrogenation of various unsaturated bonds with a selectivity of more than 90:1 and a high turnover number (TON) of 121,350. Mechanistic studies demonstrate that both empty coordination sites of Pt and dynamic B-doping are the key factors for exceptional efficiency and high selectivity. Biomass valorization is a way to promote the ‘waste-to-wealth’ concept, which is a prerequisite condition for a future sustainable lifestyle. Here, the authors demonstrate a methodology to prepare chitin-derived supramolecular nanowires-stabilized single-atom site platinum catalysts.

Organic electrosynthesis is a versatile and evergreen tool for constructing chemical compounds. However, the study of highly active electrodes has not received enough attention, which limits the further development of organic electrosynthesis. This work introduces a bottom-up route to prepare chitin-derived composite carbon aerogel electrodes (CCAEs), which can be directly used as electrodes in organic electrosynthesis systems. Various metal nanoparticles, such as Pt, Pd, RuO 2 , Cu and Ni, are well confined in these free-standing and porous CCAEs (M-CCAEs). The linear sweep voltammetry and in-situ Raman tests under electrochemical conditions show that RuO 2 -CCAEs possess good electrochemical oxidation ability for chlorine anions and good stabilizing effect on the generated chlorine radicals, which can serve as a mediator for the electrochemical C(sp 3 )-H activation. The combination of M-CCAEs with mediators achieves a series of electrochemical oxidative C(sp 3 )-H chlorination, bromination, nitration and etherification. Moreover, M-CCAEs promote the electrochemical hydrogen isotope exchange reaction of some important drug molecule structures, such as Ibuprofen, Diclofenac and Zolpidem. The study of highly active electrodes in organic electrosynthesis remains an under-investigated component of the subfield. This work introduces a bottom-up route to prepare chitin-derived composite carbon aerogel electrodes (CCAEs), which can be directly used as electrodes in organic electrosynthesis systems.

The retrieval of soil moisture (SM) using the Global Navigation Satellite System-Reflectometry (GNSS-R) technique has become a prominent topic in recent years. Although prior research has reached a spatial resolution of up to 9 km through the Cyclone Global Navigation Satellite System (CYGNSS), it is insufficient to meet the requirements of higher spatial resolutions for hydrological or agricultural applications. In this paper, we present an SM downscaling method that fuses CYGNSS and SMAP SM. This method aims to construct a dataset of CYGNSS observables, auxiliary variables, and SMAP SM (36 km) products. It then establishes their nonlinear relationship at the same scale and finally builds a downscale retrieval model of SM using the eXtreme Gradient Boosting (XGBoost) algorithm. Focusing on the southern United States, the results indicate that the SM downscaling method exhibits robust performance during both the training and testing processes, enabling the generation of a CYGNSS SM product with a 1 day/3 km resolution. Compared to existing methods, the spatial resolution is increased threefold. Furthermore, in situ sites are utilized to validate the downscaled SM, and spatial correlation analysis is conducted using MODIS EVI and MODIS ET products. The CYGNSS SM obtained by the downscaling model exhibits favorable correlations. The high temporal and spatial resolution characteristics of GNSS-R are fully leveraged through the downscaled method proposed. Furthermore, this work provides a new perspective for enhancing the spatial resolution of SM retrieval using the GNSS-R technique.

Tensile experiments were conducted for Al-7.0Zn-2.5Mg-2.0Cu-0.1Zr-0.2Sc alloy in different aging states (18 h, 24 h, 36 h) with temperature environments including room temperature, −10 °C and −30 °C. Comparative studies were made on the evolution of the precipitate phase in alloys at three kinds of aging times and the evolution of tensile properties in alloys under different ambient temperatures. The findings showed that the precipitates in Al-7.0Zn-2.5Mg-2.0Cu-0.1Zr-0.2Sc alloy were mainly in the GP zone after the solution + aging treatment η’ phase, the secondary Al3 (Sc, Zr) phase and the θ’ (Al2Cu) phase. As the aging time was prolonged, the η’ phase gradually grew and the PFZ gradually widened. At the three test temperatures, the tensile strength (TS) and yield strength (YS) of the alloys both showed a trend of first increasing before decreasing with the extension of aging time, while the elongation (A) and section shrinkage (Z) showed a decreasing trend. As the test temperature decreased, the TS and YS of the alloys increased and the A and Z of the alloys decreased. At room temperature, alloys showed a ductile fracture mode, which changed to mixed ductile and brittle fracture with decreasing test temperature.

Despite the interaction between polyphenols and polysaccharides in food products, their specific non-covalent interactions and effects on macrophage functions are not well understood. Therefore, the interaction and mechanism of purified lotus root polysaccharide (PLRP) with polyphenols, and the regulatory mechanisms of the PLRP-polyphenol complex on the macrophage functionals were studied. By combining ferulic acid (FA) and chlorogenic acid (CHA) with PLRP, the complexes PLRP-FA, PLRP-CHA and the physical mixtures PLRP&FA and PLRP&CHA were prepared, where their mass ratios of polyphenols to PLRP were 143.97 and 601.67 mg g−1. Nuclear magnetic resonance (NMR), Fourier-transform infrared (FTIR), Ultraviolet (UV), and Transmission electron microscopy (TEM) analyses confirmed that PLRP and polyphenols may engage in non-covalent interactions via hydrogen bonds and hydrophobic interactions. We confirmed that non-covalent interactions led to high molecular weight, dense complexes. Both PLRP and its polyphenol complexes stimulated NO production by macrophages to varying degrees without exacerbating lipopolysaccharide-induced inflammatory responses. PLRP and PLRP-polyphenol complexes repaired cells with impaired antioxidant capacity, depending on doses. Those results indicated that after the combination of lotus root polysaccharide and polyphenol, the molecular weight and conformation changed significantly, which influenced the biological activity. RNA-seq analysis suggested that the regulatory mechanism of PLRP-polyphenol complex in macrophages may mainly involve oxidative phosphorylation, FoxO, TNF, IL-17, MAPK, NF-kappa B, and other signaling pathways. This study investigated the effects of polyphenol binding on the physicochemical characteristics and functional activities of polysaccharides, which provided references for the development of polysaccharide functional products and the control of nutritional quality.

Bacterial infections are one of the greatest threats to wound healing, and microbial resistance has increased the demand for new antimicrobial dressings. Artificial nanozymes possess myriad considerable advantages, including low cost and high activity, for targeted biological treatments. Despite significant efforts made in nanozyme engineering, significant challenge remains that their catalytic performance is far from satisfactory in wound treatment. Herein, based on biowaste valorisation, we propose a sustainable and efficient strategy to synthesize an ultrafine‐Mn‐loaded (3.0 ± 1 nm) N,O‐doped porous nanocarbons (Mn‐PNCs) nanozyme via the Mott−Schottky effect. The nanozyme achieves mid‐temperature (45.8°C) and superior photothermal conversion efficiency (77.62%), photothermally enhanced peroxidase‐like activity that contributes to the effective treatment of methicillin‐resistant Staphylococcus aureus‐infected wounds. The photo‐enzyme platform further reduced the inflammatory response, normalized epidermal tissue regeneration, and accelerated wound healing. Notably, the mechanism demonstrated that this Mott−Schottky catalyst can trigger the rapid transfer of electrons to release reactive oxygen species (ROS) species, as a heterojunction system is strongly capable of changing the electron density within the metal. Under photothermal induction, the Mott–Schottky contact can be used to fabricate other polysaccharide‐derived nanozymes in tissue engineering, or on the high‐value application of biomass resources. Herein, we used the Mott–Schottky effect to synthesize an ultrafine‐Mn‐loaded N,O‐doped porous nanocarbons (Mn‐PNCs) nanozyme. The fabricated Mn‐PNCs nanozyme using a sustainable and efficient heteroatom‐doped strategy exhibited excellent photothermal‐enhanced, peroxidase‐like activity, thereby contributing to effective antibacterial treatment for wound.

The thermal compression experiments of the GH99 alloy were carried out at different strains from 1020 °C to 1170 °C and 0.001 s−1–1 s−1 conditions using a Gleeble-3800 thermal compression simulation tester. Construction of thermal processing maps with four instability criteria were superimposed on Murty, Prasad, Gegel, and Malas at different strains based on stress-strain data. Based on the theoretical basis, prediction results, and EBSD microstructure characterization method of four instability criteria, the suitable forming processing region and rheological instability region of the alloy were predicted. It was found that the Prasad instability criterion had the most accurate prediction results. The instability range predicted by Murty was accurate under minor strains, but as the strain increased, the expected instability range slightly increased compared to the actual range. However, the Gegel and Malas criteria have biases in predicting alloys under low-rate conditions at different strains. A scientific and rational optimization was carried out to select hot working process parameters for GH99 alloy in response to the influence of strain on its hot deformation behavior.

To promote the functional applications of lotus root polysaccharides (LRPs), the effects of noncovalent polyphenol binding on their physicochemical properties, as well as antioxidant and immunomodulatory activities, were investigated. Ferulic acid (FA) and chlorogenic acid (CHA) were spontaneously bound to the LRP to prepare the complexes LRP-FA1, LRP-FA2, LRP-FA3, LRP-CHA1, LRP-CHA2 and LRP-CHA3, and their mass ratios of polyphenol to LRP were, respectively, 121.57, 61.18, 34.79, 2359.58, 1276.71 and 545.08 mg/g. Using the physical mixture of the LRP and polyphenols as a control, the noncovalent interaction between them in the complexes was confirmed by ultraviolet and Fourier-transform infrared spectroscopy. The interaction increased their average molecular weights by 1.11~2.27 times compared to the LRP. The polyphenols enhanced the antioxidant capacity and macrophage-stimulating activity of the LRP depending on their binding amount. Particularly, the DPPH radical scavenging activity and FRAP antioxidant ability were positively related to the FA binding amount but negatively related to the CHA binding amount. The NO production of the macrophages stimulated by the LRP was inhibited by the co-incubation with free polyphenols; however, the inhibition was eliminated by the noncovalent binding. The complexes could stimulate the NO production and tumor necrosis factor-α secretion more effectively than the LRP. The noncovalent binding of polyphenols may be an innovative strategy for the structural and functional modification of natural polysaccharides.

In order to investigate the oxidation mechanism of ferritic stainless steel during long-term oxidation at high temperature. The oxidation behavior of Fe-Cr-Ti ferritic stainless steels with 10.38 wt% Cr and 17.41 wt% Cr at 800 °C and 900 °C for 100 h was studied by a constant temperature weight gain method. The morphology and composition of the oxide film were characterized by SEM, EDS and XRD. The experimental results indicate that the oxygen element mainly diffuses inward at 800 °C for two stainless steels, and the oxide film is composed of (Cr1.3Fe0.7)O3 + MnCr2O4. When the temperature rises to 900 °C, metal element mainly diffuses outward, and Fe2O3 outer oxide layer and Fe rich Fe-Cr inner oxide layer are formed in Fe11Cr0.5Ti stainless steel; Cr2O3 + Cr rich M3O4 spinel oxide film is formed in Fe18Cr0.5Ti stainless steel, while the inner layer is composed of SiO2. The main reason for the significant decrease of oxidation resistance of Fe11Cr0.5Ti stainless steel is that the low content of Cr cannot form a Cr rich oxide layer to inhibit the outward diffusion of Fe element, and the stability of oxide film is poor to protect the matrix.