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CRISPR/Cas9 system-mediated multi-copy expression of an alkaline serine protease (AoproS8) from Aspergillus oryzaewas successfully built in Aspergillus niger. Furthermore, AoproS8 was continuously knocked in the glaA, amyA, and aamygene loci in A. nigerto construct multi-copy expression strains. The yield of the AoproS8 3.0 strain was 2.1 times higher than that of the AoproS8 1.0 strain. Then, a high protease activity of 11,023.2 U/mL with a protein concentration of 10.8 mg/mL was obtained through fed-batch fermentation in a 5 L fermenter. This is the first report on the high-level expression of alkaline serine proteases in A. niger. AoproS8 showed optimal activity at pH 9.0 and 40 °C. It was used for the production of xanthine oxidase (XOD)-inhibitory peptides from eight food processing protein by-products. Among them, the duck hemoglobin hydrolysates showed the highest XOD-inhibitory activity with an IC50value of 2.39 mg/mL. Thus, our work provides a useful way for efficient expression of proteases in A. nigerand high-value utilization of protein by-products.

Atherosclerosis is driven both by hyperlipidemia and inflammation. Chitin oligosaccharides (NACOS) have shown pharmacological effects on multiple diseases via hypolipidemic and/or anti-inflammatory activities. The present study aims to evaluate whether NACOS treatment can prevent atherosclerosis induced by a high-fat-diet (HFD) in Apolipoprotein E-knockout (ApoE-/-) mice. Results showed that 300 and 900mg/kg b.w./day NACOS supplementation for 14 weeks significantly decreased atherosclerotic lesions up to 45% and 67% in compared with the HFD (P< 0.05), as measured in the valve area of the aortic root. Further, NACOS supplementation significantly reduced the serum hyperlipidemia and circulating proinflammatory cytokines including interleukin-1β, interleukin-6, monocyte chemoattractant protein-1 and tumor necrosis factor-α. NACOS decreased the hepatic Hmgcr to reduce cholesterol synthesis, activated the genes involved in reverse cholesterol transport to enhance cholesterol efflux and excretion, and reduced the intestinal Npc1L1 to lower cholesterol absorption. Additionally, NACOS enhanced cecum short chain fatty acids production and intestinal integrity. Thus, NACOS supplementation ameliorated atherosclerosis via altering lipid metabolism and reducing inflammation. These findings indicate that NACOS may be a potential functional food material for attenuating atherosclerosis development.

This paper demonstrates both the high-performance microwave absorption properties and the superior thermal stability of graphene/multiwalled carbon nanotubes (MWNTs)/poly(p-phenylenebenzobisoxazole) (PBO) composites synthesized via in situ polymerization of functionalized PBO precursor with graphene oxide/MWNTs nanocomposites, followed by high-temperature calcination. The incorporation of three-dimensional graphene/MWNTs network significantly improved the reflection loss of PBO composites (−50.17 dB at 12.58 GHz) by over 20 times than that of pure PBO (−2.33 dB at 12.58 GHz) with a sample thickness of only 2.6 mm. The effect of graphene/MWNTs content on the microwave absorption performance was also investigated. The graphene/MWNTs/PBO composite shows great promise as a microwave absorber in high-temperature environments.

MXenes, a large family of two-dimensional (2D) early transition metal carbides and nitrides, have excellent electrical and electrochemical properties, which can also be explored in assemblies with other 2D materials, like graphene and transition metal dichalcogenides (TMDs), creating heterostructures with unique properties. Understanding the interaction mechanism between 2D materials is critical for the design and manipulation of these 2D heterostructures. Our previous work investigated the interaction between SiO2and two MXenes (Ti3C2Txand Ti2CTx). However, no experimental research has been done on MXene interlayer interactions and interactions in MXene heterostructures. Here, we used atomic force microscopy (AFM) with SiO2tip and Ti3C2Txand Ti2CTxMXene-coated tips, respectively, to measure the adhesion energies of graphene, MoSe2, Ti3C2Tx, and Ti2CTxMXene with other 2D materials. The measured adhesion energies show that only the interfaces involving graphene demonstrate dependence on the number of material monolayers in a stack. Comparing 40 interacting pairs of 2D materials, the lowest adhesion energy (∼0.27 J/m2) was found for the interfaces involving MoSe2and the highest adhesion energy was observed for the interfaces involving Ti3C2Tx(∼1.23 J/m2). The obtained set of experimental data for 2D interfaces involving MXenes provides a basis for a future in-depth understanding of adhesive mechanisms at interfaces between 2D materials, which is an important topic for the design of 2D heterostructures with controlled interfacial strength and properties.

Monoclinic WO3is considered to be a promising photoanode due to high theoretical photocurrent density and quantum efficiency. However, the practical photoelectrochemical (PEC) performance is considerably inferior to the theoretical value because of severe surface charge recombination. Herein, an Ag nanoparticle (NP) modified WO3composite photoanode was prepared via in situcathodic reduction to boost the surface charge separation. The various PEC performance indicators such as the photocurrent, incident photon-to-current efficiency, and applied bias photon-to-current efficiency have been improved to varying degrees upon the modifications of the Ag NPs. Electrochemical impedance spectroscopy and Mott-Schottky analysis demonstrate that the Ag NPs greatly enhance the surface charge separation efficiency of WO3, thus improving the PEC performance.Due to the relatively large difference in work function between Ag NPs and monoclinic WO3nanosheets, a space charge layer will be formed at the interface when they are in close contact. The space charge layer greatly promotes the interface charge separation and species transfer, thus boosting the photocurrent density.

Hydroxyapatite luminescent nanocrystallines doped with 6 mol.% Tb3+(Tb-HA) were prepared via chemical deposition method and calcined at different temperature, and the effects of calcinations temperature on the luminescence intensity and fluorescent lifetime were studied. TEM image of Tb-HA revealed that the shape of nanocrystallines changed from needle-like to short rod-like and sphere-like with the increase of calcinations temperature; while the particles sizes decreased from 190 nm to 110 nm. The crystallinity degree increased. The typical emission peaks attributed to Tb3+ions were observed in emission spectra of 6 mol.% Tb-HA under 378 nm excitation. The luminescent intensity of Tb-HA, which showed the fluorescence quenching, firstly enhanced and then decreased at 700 °C; while the fluorescent lifetime increased firstly and then decreased after 600 °C. Furthermore, the ratio of intensity between 545 nm and 490 nm corresponding to electric-dipole and magnetic-dipole transition (IR: IO) increases firstly and then decreases, which revealed that the proportion of substitute type and site of Ca2+ions by Tb3+ions were helpful to realize the substitute process and functional structure design.

Dry eye disease (DED) is a prevalent chronic eye disease characterized by an aberrant inflammatory response in ocular surface mucosa. The immunological alterations underlying DED remain largely unknown. In this study, we employed single-cell transcriptome sequencing of conjunctival tissue from environment-induced DED mice to investigate multicellular ecosystem and functional changes at different DED stages. Our results revealed an epithelial subtype with fibroblastic characteristics and pro-inflammatory effects emerging in the acute phase of DED. We also found that T helper (Th)1, Th17, and regulatory T cells (Treg) were the dominant clusters of differentiation (CD)4+T-cell types involved in regulating immune responses and identified three distinct macrophage subtypes, with the CD72+CD11c+subtype enhancing chronic inflammation. Furthermore, bulk transcriptome analysis of video display terminal-induced DED consistently suggested the presence of the pro-inflammatory epithelial subtype in human conjunctiva. Our findings have uncovered a DED-associated pro-inflammatory microenvironment in the conjunctiva, centered around epithelial cells, involving interactions with macrophages and CD4+T cells, which deepens our understanding of ocular surface mucosal immune responses during DED progression.

A novel glutamate-dependent poly-γ-glutamic acid (γ-PGA)-producing strain Bacillus velezensisCAU263 isolated from Chinese traditional Douchiwas evaluated. An efficient method of γ-PGA production was performed by this strain via solid-state fermentation (SSF) using guar meal. The maximal yield of γ-PGA reached 158.5 g/kg dry weight (DW) in 250 mL flasks and 155.1 g/kg DW in shallow tray, respectively. The molecular weight of γ-PGA was 3.8 × 106 Da, the ratio of L/D-glutamic acid was 26.1% and 73.9%. Additionally, γ-PGA significantly improved the operating characteristics of wheat dough, the specific volume of bread was increased by 15.8% and the bread hardness was reduced by 44.2% owing to the addition of 0.3 g/kg γ-PGA. Thus, γ-PGA could be produced by Bacillus velezensisCAU263 at high level using guar meal and might have potential application prospect in food industry.

Selective hydrogenation with high efficiency under ambient conditions remains a long-standing challenge. Here, a yolk–shell nanostructured catalyst, PdAg@ZIF-8, featuring plasmonic PdAg nanocages encompassed by a metal–organic framework (MOF, namely, ZIF-8) shell, has been rationally fabricated. PdAg@ZIF-8 achieves selective (97.5%) hydrogenation of nitrostyrene to vinylaniline with complete conversion at ambient temperature under visible light irradiation. The photothermal effect of Ag, together with the substrate enrichment effect of the catalyst, improves the Pd activity. The near-field enhancement effect from plasmonic Ag and optimized Pd electronic state by Ag alloying promote selective adsorption of the −NO2group and therefore catalytic selectivity. Remarkably, the unique yolk–shell nanostructure not only facilitates access to PdAg cores and protects them from aggregation but also benefits substrate enrichment and preferential −NO2adsorption under light irradiation, the latter two of which surpass the core–shell counterpart, giving rise to enhanced activity, selectivity, and recyclability.

A relatively new and large class of materials, two-dimensional (2D) early transition metal carbides (MXenes), produced by etching of Aelements from their parent MAXphases, have demonstrated outstanding performance in many applications. However, the mechanical behavior of MXenes, which is critical for device fabrication and performance, has not been sufficiently investigated. In this work we report the results from in-situscanning electron microscopy (SEM) uniaxial compression experiments conducted on two types of multilayer accordion-like MXene particles, Ti2CTxand Ti3C2Tx, along both in-plane and out-of-plane directions. Significant anisotropic behavior was observed associated with progressive failure mechanisms. Molecular dynamics (MD) modeling was conducted to analyze the behavior of intact and defected monolayer Ti2C and Ti3C2MXenes in tension and compression. Structural analysis for both in- and out-of-plane uniaxial compression is presented and compared with experimental data, revealing that the overall mechanism is controlled by the intrinsic elastic and plastic properties of MXenes, as well as their multilayer structures. The intrinsic material properties were estimated based on structural analysis from experimental results.