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Two nanocomposites with a hierarchical structure (GO@CuSilicate@Fe3O4 and GO@Fe3O4@CuSilicate) were fabricated in this paper. These as-synthesized nanocomposites were analyzed for their structural,...

Endophytic fungi of medicinal plants have attracted wide attention due to their various active biochemical substances that are similar to those of the host plants and can be easily fermented and cultured. As a traditional medicine and food homologous plant in Xinjiang, Brassica rapa L. has a long history of applications. Recently, it has been shown that B. rapa L. has hypoglycemic, antimicrobial, immunomodulatory, and antioxidant properties. However, there are no studies on the function and diversity of enophytic fungi of B. rapa L. Four endophytic fungus (pr6, pr7, pr8, and pr10) strains were isolated from B. rapa L. in our laboratory. The metabolic extracts from pr10 have significant effects in terms of antitumor activity. In this study, in terms of types and contents, compared with those of the other three endophytic fungi, the dominant metabolites of pr10 were determined by comparative metabolomics analysis. The results of metabolomics analysis indicated that the metabolites of pr10 are rich in amino acids and sugar derivatives such as trehalose, whose ability to inhibit the A549 cell line has been proved. This study provides a theoretical basis for the development and utilization of B. rapa L. and its endophytic fungi to form antitumor agents.

A femtosecond (fs)-laser-processed surface that repels liquid polymer in water is reported in this paper. We define this phenomenon as the "superpolymphobicity". Three-level microstructures (including microgrooves, micromountains/microholes between the microgrooves, and nanoripples on the whole surface) were directly created on the stainless steel surface via fs laser processing. A liquid polydimethylsiloxane (PDMS) droplet on the textured surface had the contact angle of 156 ± 3° and contact angle hysteresis less than 4° in water, indicating excellent underwater superpolymphobicity of the fs-laser-induced hierarchical microstructures. The contact between the resultant superhydrophilic hierarchical microstructures and the submerged liquid PDMS droplet is verified at the underwater Cassie state. The underwater superpolymphobicity enables to design the shape of cured PDMS and selectively avoid the adhesion at the PDMS/substrate interface, different from the previously reported superwettabilities. As the examples, the microlens array and microfluidics system were prepared based on the laser-induced underwater superpolymphobic microstructures.

The ideal product of rare-earth-doped phosphors should have uniform particle size distribution and homogeneous doping ions in each particle, and therefore, intensified micromixing at mesoscale is highly required. In this article, inspired by the concept of "mesoscience", we demonstrate the tuning of Eu3+ doping in GdBO3 microparticles at mesoscale by a high-gravity-assisted reactive precipitation-coupled calcination process. The high-gravity environment and tiny droplets generated by the high-gravity rotating packed bed (RPB) reactor lead to significant intensification of mass transfer and micromixing, which are beneficial for the homogeneous doping of Eu3+ in the host material during reactive precipitation in liquid solution. Under excitation at 395 nm, the emission spectra of the Eu3+-doped phosphors exhibit a narrow-band red emission centered at 625 nm and the highest intensity was observed at x = 0.2. The RPB products show higher intensity than that of the control group even when the reaction time was shortened to 1/6. After calculation, the quenching in the sample most likely results from dipole-dipole interactions. The chromaticity coordinates for the RPB sample was measured as (0.598, 0.341) with a quantum yield of up to 78.11%, and the phosphors exhibit good thermal stability at 423 K. The phosphors were used as the luminescent materials for light-emitting diodes (LEDs), and the devices showed good performance. Our preliminary study illustrated that high-gravity-assisted approaches are promising for tuning the doping of rare-earth ions in microparticles at mesoscale toward efficient production of phosphors for LEDs.

Fuel cells hold great promise for clean and sustainable energy, whereas their widespread commercialization strongly depends on the development of highly efficient and stable electrocatalysts. Herein, three-dimensional fluffy PtPd nanocorals (NCs) loaded on two-dimensional (2D) hexagonal boron nitride (h-BN) supports were successfully achieved by a simple one-step strategy based on ultraviolet (UV) laser-excited photochemical reaction. As for alcohol oxidation reaction, the h-BN/PtPd NCs with unique nanoporous surface provide more enhanced electrocatalytic performances than many previous nanocatalysts, owing to abundant active sites and plentiful charge-transfer channels formed on high electrode–electrolyte contact area. Especially, the mass activity of h-BN/PtPd NCs is about 962.8 mA mgPtPd–1 in methanol oxidation reaction in alkaline solution, which can be maintained at ∼274.9 mA mgPtPd–1 (28.6% of the initial one) even after a 5 × 104 s durability test. The present work not only offers an advanced electrocatalyst for long-term fuel cells but also provides a versatile route for construction of complex metallic nanocomposites on 2D supports, holding great potential for diverse energy-related applications.

Cellulose nanopaper is a strong lightweight material made from renewable resources with a wide range of potential applications, from membranes to electronic displays. Most studies on nanopaper target high mechanical strength, which compromises ductility and toughness. Herein, we demonstrate the fabrication of highly ductile and tough cellulose nanopaper via mechanical fibrillation of hemicellulose-rich wood fibers and dispersion of the obtained cellulose nanofibrils (CNFs) in an ionic liquid (IL)–water mixture. This treatment allows hemicellulose swelling, which leads to dissociation of CNF bundles into highly disordered long flexible fibrils and the formation of a nanonetwork as supported by cryogenic transmission electron microscopy (cryo-TEM) imaging. Rheology of the suspensions shows a 300-fold increase in storage and loss moduli of CNF–IL–water suspensions, compared to their CNF–water counterparts. The nanopaper prepared by removing the IL–water shows a combination of large elongation (up to 35%), high strength (260 MPa), and toughness as high as 51 MJ/m3, because of efficient interfibrillar slippage and energy dissipation in the highly disordered isotropic structure. This work provides a nanostructure-engineered strategy of making ductile and tough cellulose nanopaper.

Fluorescent carbon dots (FCDs) have received considerable attention because of the great potential for a wide range of applications, from bioimaging to optoelectronic devices. In this work, we reported the synthesis of nitrogen-doped FCDs with an average size of 2 nm in a subcritical water apparatus by using biomass waste (i.e., expired milk) as the precursor. The obtained FCDs were highly dispersed in aqueous solution because of the presence of O-containing functional groups on their surfaces. Under the excitation of ultraviolet and blue light, the FCDs exhibited excitation wavelength-dependent fluorescence in the emission range of 400–550 nm. The FCDs could be easily taken up by HeLa cells without additional surface functionalization, serving as fluorescent nanoprobes for bioimaging. The applications of FCDs as sensing agents for the detection of Fe3+, solid-state fluorescent patterning, and transparent hybrid films were also performed, demonstrating their potential for solid-state fluorescent sensing, security labeling, and wearable optoelectronics.