Search

Cell fusion is an essential event in many biological processes and has gained increasing attention in the field of biotechnology. In this study, we demonstrate an effective and convenient strategy for cell capture, pairing, and fusion based on oscillating bubbles within an acoustofluidic device. Multirectangular structures of the same size were fabricated at the sidewall of polydimethylsiloxane to generate monodisperse microbubbles. These microbubbles oscillated with a similar amplitude under single-frequency acoustic excitation. Cells were simultaneously captured and paired on the surface of the oscillating bubbles within 40 ms, and the efficiency reached approximately 90%. Homotypic or heterotypic cell membrane fusion was achieved within 15 and 20 min, respectively. More importantly, the homotypic fused cells enabled migration and proliferation at 24 h, indicating that the important biological functions were not altered. [ABSTRACT FROM AUTHOR]

The patterning of nanoparticles, which are promising photothermal agents, is of great importance to selectively and precisely ablate tissues by thermal effects. In this paper, we demonstrated that nano-sized gold particles (gold nanocages, AuNCS) with a hollow structure could be used to generate various wavefront patterns of surface acoustic waves (SAWs) and the aligned AuNC lines facilitated the destruction of cancer cells by the thermal effect with high spatial resolution. The hollow structure improved the acoustic sensitivity of AuNCs, making them more sensitive to the acoustic radiation force. Moreover, the multi-scale patterning of AuNCs could be achieved by the interference of multiple acoustic beams. Given the photothermal characteristics of AuNCs, selective temperature elevation within a micrometer-sized region could be realized when the patterned AuNCs were irradiated by a laser. The cancer cells where the patterned AuNCs were located were eliminated by thermal ablation, while other cells remained alive. In particular, the acoustic frequency used in this study was as low as 11. 35 MHz and was in the range of diagnostic ultrasound (less than 12 MHz), offering a potential to serve as a powerful tool in clinical applications. [ABSTRACT FROM AUTHOR]

The ability to develop low-cost electrocatalysts with high efficiency and strong stability for acid oxygen evolution reactions (OER) will enable commercial applications of powerful proton exchange membranes (PEM) in water splitting devices. However, this remains challenging because most nonprecious metal-based electrocatalysts suffer from strong corrosion in acid media. Herein, we crafted porous N, S-doped carbon network-immobilized ultrafine pentlandites (i.e., Ni4Fe5S8) nanoparticles (denoted P-NSC/Ni4Fe5S8-1000) by employing rationally designed nanohybrids comprised of liquid polymer-coated binary Prussian blue analogue (PBA) nanoparticles (NPs) as precursors. Afterwards, the P-NSC/Ni4Fe5S8-1000 nanocomposites were exploited as OER electrocatalysts, with a small onset potential of 1.53 V vs. RHE (1 mA cm−2) and strong stability in 0.5 M H2SO4 solution, outperforming commercial RuO2 electrocatalysts. As revealed by both experimental results and DFT calculations, there is a synergy effect on the P-NSC/Ni4Fe5S8-1000 for OER: the pyridinic-N, S doped carbon could easily adsorb water, and then the highly active Fe sites of Ni4Fe5S8 NPs could catalyze the absorbed water to oxygen gas. Furthermore, the hierarchically porous nanostructure could promote multiphase transport during acid OER. Therefore, this work, for the first time, highlighted the great potential of pentlandites NPs-based nanocomposites as efficient and stable electrocatalysts for acid OER. [ABSTRACT FROM AUTHOR]

Fabricating heterointerfaces with optimized electronic structures is a robust strategy to boost the activity of electrocatalysts. Herein, for the first time, we demonstrate that the heterointerfaces of metallic Ag and NiFe-oxides on hierarchical nanoarrays facilitate the charge transfer during the OER and optimize the electronic state of NiFe-oxides, thereby significantly boosting the activity for the OER. [ABSTRACT FROM AUTHOR]

In this work, a facile one-step solvothermal method with the assistance of hydrochloric acid has been developed to prepare well-dispersed CeO2 hollow nanospheres with high surface areas. The effects of hydrochloric acid on the growth mechanism and the size distribution are investigated in detail. It is found that the hydrogen ions expedite the nucleation rate of the CeO2 nuclei in the nucleation course, while the chloride ions accelerate the Ostwald ripening in the acidic environment. Both the hydrogen ion (H+) and the chloride ion (Cl−) are confirmed to play a key role in the formation of hollow morphology. Based on our experiments, a HCl-assisted oxidation–nucleation with an Ostwald ripening process mechanism was proposed. Furthermore, Au nanoparticles with a size of 2.5–6 nm were uniformly deposited on the surface of the ceria support by a simplified reduction process with sodium borohydride (NaBH4). The synthesized Au/CeO2 nanospheres exhibit a higher catalytic activity in CO oxidation than pure ceria nanospheres due to the existence of different Au species (metallic Au0 and positively charged Auδ+) and the strengthened interfacial interactions between the Au NPs and the ceria support. [ABSTRACT FROM AUTHOR]

Uniform-sized and monodisperse CeO2 mesoporous hollow nanospheres composed of ceria nanocrystals were synthesized via a template-free and surfactant-assisted benign hydrothermal route. On the basis of a time-dependent experiment, the precipitation–dissolution–renucleation–assembly and Ostwald ripening processes mechanism is proposed for the formation of the CeO2 mesoporous hollow spheres. Poly(vinyl-pyrrolidone) (PVP) was applied as a surfactant to facilitate the reassembly of the CeO2 nanoparticles and the formation of the mesoporous shell of the hollow nanospheres. By increasing the amount of PVP, the mesoporous shell of the hollow spheres could be fabricated and became more apparent. Meanwhile, altering the amounts of H2O2 could control the size of the primary nanocrystals via affecting the nucleation/growth process of them, which is another key factor in the formation of the hollow structure and the uniform, monodispersed nanoparticles. The catalytic test results show that the as-obtained CeO2 mesoporous hollow spheres exhibited desirable CO catalytic properties. The synthesized Au–CeO2 nanospheres demonstrate a higher catalytic activity in CO oxidation than pure ceria nanospheres. [ABSTRACT FROM AUTHOR]

A facile hydrothermal method has been employed to fabricate monodisperse Mn2O3 nano-flowers and Mn3O4 nano-ellipsoids. The possible mechanism of crystal growth was suggested based on time-dependent experiments, and the role that H2O2 played in the determination and formation of products Mn2O3 and Mn3O4 was investigated. These MnOx nano-particles have been demonstrated to be catalytically stable and active for CO oxidation. [ABSTRACT FROM AUTHOR]