Experimental investigation on hydrodynamic behavior in a spouted bed with longitudinal vortex generators

A spouted bed with longitudinal vortex generator (LVG) of sphere was built to enhance radial movement of particles. Particle Image Velocimetry (PIV) was applied to explore effects of longitudinal vortex flow and physical properties of particles on their radial velocity in a 152-mm-diametered spouted bed. The results show that, Compared with the conventional spouted bed, the existence of longitudinal vortex generator gives rise to a large amount of secondary fine vortex flow in the cross section of spouted bed. The enhancement factors of particles movement η with different particle densities are all greater than 1. The smaller the particle density, the more significant the effect of the longitudinal vortex on the radial velocity of the particles. The single-row LVGs can produce a good radial enhancement effect of particle movement when the particle handling capacity is small (H₀ = 165 mm). With the increase of the height of the static bed (H₀), the enhancement of the radial velocity of particles in the spouted bed by multi-row LVGs (three rows) increases gradually, which indicates that the multi-row LVGs have a better overall effect on the enhancement of particle motion in the spouted bed with more particle handling capacity (H₀ = 195 mm, 225 mm).     

Magnetic Heating Amorphous NiFe Hydroxide Nanosheets Encapsulated Ni Nanoparticles@Wood Carbon to Boost Oxygen Evolution Reaction Activity

The oxygen evolution reaction (OER) has significant effects on the water-splitting process and rechargeable metal-air batteries; however, the sluggish reaction kinetics caused by the four-electron transfer process for transition metal catalysts hinder large-scale commercialization in highly efficient electrochemical energy conversion devices. Herein, a magnetic heating-assisted enhancement design for low-cost carbonized wood with high OER activity is proposed, in which Ni nanoparticles are encapsulated in amorphous NiFe hydroxide nanosheets (a-NiFe@Ni-CW) via direct calcination and electroplating. The introduction of amorphous NiFe hydroxide nanosheets optimizes the electronic structure of a-NiFe@Ni-CW, accelerating electron transfer and reducing the energy barrier in the OER. More importantly, the Ni nanoparticles located on carbonized wood can function as magnetic heating centers under the effect of an alternating current (AC) magnetic field, further promoting the adsorption of reaction intermediates. Consequently, a-NiFe@Ni-CW demonstrated an overpotential of 268 mV at 100 mA cm⁻² for the OER under an AC magnetic field, which is superior to that of most reported transition metal catalysts. Starting with sustainable and abundant wood, this work provides a reference for highly effective and low-cost electrocatalyst design with the assistance of a magnetic field.     

Adhesive Composite Microspheres with Dual Antibacterial Strategies for Infected Wound Healing

Skin damage and infection pose a severe challenge to human health. Construction of a novel versatile dressing with good anti-infection and healing-promoting abilities is greatly expected. In this paper, nature-source-based composite microspheres with dual antibacterial mechanisms and bioadhesive features by microfluidics electrospray for infected wound healing is developed. The microspheres enable sustained release of copper ions, which not only show long-term antibacterial properties, but also play important role in wound-healing-related angiogenesis. Additionally, the microspheres are coated with polydopamine via self-polymerization, which renders the microspheres adhesive to the wound surface, and further enhance the antibacterial ability through photothermal energy conversion. Based on the dual antibacterial strategies provided by copper ions and polydopamine as well as the bioadhesive property, the composite microspheres exhibit excellent anti-infection and wound healing performances in a rat wound model. These results, along with the nature-source-based composition and biocompatibility, indicate the great potential of the microspheres in clinical wound repair.     

Scalable Production of Biomedical Microparticles via High-Throughput Microfluidic Step Emulsification

Drug microcarriers are widely used in disease treatment, and microfluidics is well established in the preparation of microcarrier particles. A proper design of the microfluidic platform toward scalable production of drug microcarriers can extend its application values in wound healing, where large numbers of microcarriers are required. Here, a microfluidic step emulsification method for the preparation of monodisperse droplets is presented. The droplet size depends primarily on the microchannel depth rather than flow rate, making the system robust for high-throughput production of droplets and hydrogel microparticles. Based on this platform, basic fibroblast growth factor (bFGF) is uniformly encapsulated in the microparticles, and black phosphorus (BP) is incorporated for controllable release via near-infrared (NIR) stimulation. The microparticles serve as drug carriers to be applied to the wound site, inducing angiogenesis and collagen deposition, thereby accelerating wound repair. These results indicate that the step emulsification technique provides a promising solution to scalable production of drug microcarriers for wound healing as well as tissue regeneration.     

Enhancing Prostate‐Cancer‐Specific MRI by Genetic Amplified Nanoparticle Tumor Homing

Precise localization and visualization of early‐stage prostate cancer (PCa) is critical to improve the success of focal ablation and reduce cancer mortality. However, it remains challenging under the current imaging techniques due to the heterogeneous nature of PCa and the suboptimal sensitivity of the techniques themselves. Herein, a novel genetic amplified nanoparticle tumor‐homing strategy to enhance the MRI accuracy of ultrasmall PCa lesions is reported. This strategy could specifically drive TfR expressions in PCa under PCa‐specific DD3 promoter, and thus remarkably increase Tf‐USPIONs concentrations in a highly accurate manner while minimizing their non‐specific off‐target effects on normal tissues. Consequently, this strategy can pinpoint an ultrasmall PCa lesion, which is otherwise blurred in the current MRI, and thereby addresses the unmet key need in MRI imaging for focal therapy. With this proof‐of‐concept experiment, the synergistic gene–nano strategy holds great promise to boost the MRI effects of a wide variety of commonly used nanoscale and molecular probes that are otherwise limited. In addition, such a strategy may also be translated and applied to MR‐specific imaging of other types of cancers by using their respective tumor‐specific promoters.     

SupraCells: Living Mammalian Cells Protected within Functional Modular Nanoparticle‐Based Exoskeletons

Creating a synthetic exoskeleton from abiotic materials to protect delicate mammalian cells and impart them with new functionalities could revolutionize fields like cell‐based sensing and create diverse new cellular phenotypes. Herein, the concept of “SupraCells,” which are living mammalian cells encapsulated and protected within functional modular nanoparticle‐based exoskeletons, is introduced. Exoskeletons are generated within seconds through immediate interparticle and cell/particle complexation that abolishes the macropinocytotic and endocytotic nanoparticle internalization pathways that occur without complexation. SupraCell formation is shown to be generalizable to wide classes of nanoparticles and various types of cells. It induces a spore‐like state, wherein cells do not replicate or spread on surfaces but are endowed with extremophile properties, for example, resistance to osmotic stress, reactive oxygen species, pH, and UV exposure, along with abiotic properties like magnetism, conductivity, and multifluorescence. Upon decomplexation cells return to their normal replicative states. SupraCells represent a new class of living hybrid materials with a broad range of functionalities.     

Effect of Zn addition on two-step aging behaviour of Al–Mg–Si–Cu alloy

This study investigates the effect of Zn addition two-step behaviour in an Al–Mg–Si–Cu alloy. During pre-aging at 100°C for 3?h, the Zn can partition into clusters because of the strong Zn–Mg interaction, prompting the formation of clusters. During subsequent artificial aging at 180°C for up to 240?min (peak hardness condition), the Zn does not significantly partition into clusters or precipitates, and the majority of Zn remains in the Al matrix. However, the presence of Zn in the matrix stimulates the transformation from clusters to GP zones to β′′ phases. The enhanced formation of GP zones and β′′ phases correlates well with the remarkable age-hardening response.     

Synthesis of phosphonate-containing mesoporous silica spheres under basic condition

Phosphonate-containing mesoporous silica (PMPS) spheres were successfully synthesized using diethyl(2-bromoethyl)phosphonate and non-ionic and cationic surfactants. The spherical PMPS particles with the mesopores were effectively formed under the basic condition through the hydrolysis and condensation reactions of tetraethoxysilane, even though the BET surface area of the particles decreased with increasing the added phosphonate amount. The hollow structures with the mesopores were obtained in the preferential amount of the phosphonate.     

基于客户/服务器的绝缘诊断及管理专家系统的开发

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