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In this work, we designed a simple and low cost acid-dissolved/alkali-solidified self-sphering shaping method (AASS) to automatically fabricate three-dimension (3D) stem cell expansion microsphere scaffolds in large scale to satisfy the urgent need for stem cells in tissue engineering and clinical medicine research. We chose chitosan as the main part of microsphere scaffold, graphene oxide of 3 wt% as the strength agent, and genipin as the fluorescence generator to fabricate fluorescent chitosan (CS)/graphene oxide (GO) hybrid microspheres. The diameters of the hybrid microspheres are about 400 μm with the diameter error less than 10%, which is suitable for stem cells spreading. These hybrid microspheres with good biocompatibility can support the cells’ spread, growth and proliferation. After cultured for 5 days, the total number of cells on microspheres has almost increased fourfold. Most importantly, the microspheres can maintain the cell type. After cultured for 7 days, almost all cells still express main markers of human umbilical cord mesenchymal stem cells (HUMSCs). The hybrid microspheres can support long-time stem cell expansion because of their good mechanical strength, controllable degradability, and low expansion rate when soaked in media. Furthermore, their autofluorescence also makes observing and tracking the stem cells behavior on surface of microsphere scaffolds more convenient. This research provides a powerful method for mass-producing chitosan/graphene oxide hybrid microspheres for 3D stem cells expansion. This method is easy to be put into industrial production, and may have tremendous value in medicinal and clinical applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • CoSe@NC nanofiber membrane was synthesized by electrospinning and thermal annealing method. • CoSe nanoparticles have strong adsorption and catalytic capability for polysulfides. • Li-S battery with CoSe@NC nanofiber membrane as interlayer shows excellent electrochemical performance. Lithium sulfur (Li-S) batteries have attracted tremendous attention due to their low cost and high theoretical capacity. However, the serious polysulfides shuttle and slow redox reaction kinetics hinder their large-scale commercial applications. Various attempts have been made to solve the problems. Herein, a CoSe@NC nanofiber membrane was prepared by electrospinning method and used as independent functional interlayer for the Li-S batteries. The visualized adsorption experiments show that the CoSe@NC nanofiber exhibits strong adsorption capability for polysulfides; In addition, CoSe nanoparticles with strong catalytic activity can accelerate the conversion of polysulfides. The adsorption-catalysis synergy of CoSe@NC can therefore effectively enhance the rate performance and cycling stability of Li-S batteries. The cell assembled with CoSe@NC functional interlayer delivers a high initial reversible discharge capacity of 1317 mAh g−1 at 0.1 C rate. After 200 cycles at 1.0 C, the capacity decay rate is only 0.16% per cycle. This work provides a feasible way to promote the electrochemical performance of Li-S batteries [ABSTRACT FROM AUTHOR]

• A CNTs-based biocatalytic nano-platform with steady magnetic recyclability was prepared. • The CNTs were filled with Fe 3 O 4 nanoparticles, the holes shrunk and surface-loadable for enzymes. • Its role can be changed from biocatalyst to biosensor by loading different enzymes. The creation of biocatalytic nano-platform with high performance is the focus of attention in the field of enzyme catalysis. However, most enzyme nanoreactors suffer from poor versatility and recovery ability. Herein, we construct a versatile biocatalytic nano-platform with steady magnetic recyclability through hybrid magnetic carbon nanotubes (named by h-CNT/Fe 3 O 4 /ZrO 2), realize the role of biocatalyst by the covalent attachment of lipase. On the other side, glucose oxidase (GOx) was immobilized on the h-CNT/Fe 3 O 4 /ZrO 2 to prepare dual enzyme system (GOx@h-CNT/Fe 3 O 4 /ZrO 2) for glucose detecting via colorimetric assay, this is its role as biosensor. In order to build an amphiphilic nano-bio interface, hydroxyl contained carbon nanotubes were selected as the substrate material of nano-platform. We punch lots of mesopores on the tube wall and inject Fe 3 O 4 nanoparticles into inner nanotubes via these openings, then shrunk mesoporous by zirconia to maintain the magnetic recyclability. We believed such an architecture that can not only offer the comfortable bio-nano interfaces for enzyme but also effectively avoid the loss of magnetism thus brings constant recyclability. [ABSTRACT FROM AUTHOR]

[Display omitted] • A molten salt method for large-scale synthesis of NiNb 2 O 6 submicron particles is proposed. • The NiNb 2 O 6 anode material exhibits an outstanding cycling stability and rate performance up to 20 A g−1 in a Li half-cell. • The assembled NiNb 2 O 6 ||LiFePO 4 full cell can retain 89.3% capacity after 800 cycles at 1.0 A g−1. Niobium-based oxides as lithium-ion battery anode materials have attracted much attention due to their excellent fast-charging capability. However, the solid-phase synthesis of niobates often involves harsh reaction conditions, especially high temperature over 1100 °C. Herein, a molten salt method is proposed to synthesize NiNb 2 O 6 submicron particles, with synthetic temperature of 900 °C, gram-scale production and high reaction yield of 96.6%. Remarkably, NiNb 2 O 6 at the sub-micron scale shows superior electrochemical performance compared to the micron and nano scale sizes, i.e., reversible capacity of 320.9 mAh g−1 after 500 cycles at 2.0 A g−1 (≈8.5C) and high capacity retention of 85.8% over 5000 cycles at 20 A g−1 (≈85C), mainly arising from the pseudo-capacitance electrochemical behavior and stable structure of material during repeated cycles. Moreover, the assembled NiNb 2 O 6 ||LiFePO 4 full cell can retain 89.3% capacity after 800 cycles at 1.0 A g−1. This work offers a simple and efficient method for preparing NiNb 2 O 6 submicron particles as anode material for fast -charging lithium-ion batteries. [ABSTRACT FROM AUTHOR]

[Display omitted] • CoN-Mo 2 N heterostructure is synthesized by nitriding the CoMoO 4 nanorods; • CoN-Mo 2 N heterostructure has strong adsorption/bidirectional catalytic capacity for polysulfides; • Li-S cells assembled with CoN-Mo 2 N modified separators show excellent electrochemical performance. A single functional material can hardly simultaneously overcome the problems of poor conductivity of active sulfur, shuttle effect and slow redox reaction kinetics of lithium polysulfides (LiPSs) in rechargeable lithium-sulfur batteries. Herein, a multi-functional CoN-Mo 2 N heterostructure nanorods with excellent adsorption capability and bidirectional catalytic ability is introduced. It is found that the CoN-Mo 2 N heterostructure has a significant interaction with LiPSs, and its chemical affinity can promote the adsorption of LiPSs; The Li 2 S nucleation and electrochemical testing results show that the CoN-Mo 2 N heterostructure can promote the uniform nucleation and rapid growth of Li 2 S, where CoN tends to promote the oxidation reaction kinetics, and Mo 2 N promotes the reduction reaction kinetics. The assembled Li-S cells with CoN-Mo 2 N modified separators can deliver outstanding rate performance and long-cycling stability, with a high initial reversible discharge capacity of 1605.8 mAh g−1 at 0.1C, and capacity decay rate per cycle of 0.198 % after 200 cycles at 0.2C. [ABSTRACT FROM AUTHOR]

• Biodegradable CoSnO 3 nanocubes are employed as sonosensitizers and nanozymes. • GQD/CoSnO 3 is constructed by depositing GQD topoisomerases inhibitors on CoSnO 3. • Heterojunction-fabricated GQD/CoSnO 3 shows cascaded amplification of ROS generation. • Tumor-specific release of GQDs for chemotherapy is realized after completion of SDT. • GQD/CoSnO 3 achieves complete tumor eradication through chemotherapy, SDT, and NCT. Albeit nanozymes are widely applied for nanocatalytic therapy (NCT), the unsatisfactory catalytic activity of nanozymes accompanied by complex tumor microenvironment (TME) greatly pose a barrier to the therapeutic effect of NCT. Moreover, developing a high-efficiency nanozyme with biodegradability is still a huge challenge, which hinders their further clinical translation. Herein, pH-responsive biodegradable CoSnO 3 nanocubes are synthesized and employed as sonosensitizers and nanozymes due to their narrow bandgaps (1.6 eV) and Co2+/Sn4+-mediated multi-enzyme activities. After depositing the graphene quantum dot (GQD) topoisomerase inhibitors on CoSnO 3 nanocubes, the heterojunction-fabricated GQD/CoSnO 3 shows cascaded amplification of ROS generation, which is ascribed to the inhibition of electron-hole pair recombination, Co2+-mediated peroxidase (POD)-mimic catalytic reaction to generate OH, Co3+/Sn4+-mediated depletion of overexpressed GSH, and catalytic decomposition of endogenous H 2 O 2 for providing more O 2 for enhanced SDT. More importantly, GQD/CoSnO 3 heterojunctions are slowly degraded in the weakly acidic TME, resulting the tumor-specific release of GQDs after completion of SDT, which could induce DNA damage and cell apoptosis for chemotherapy to further enhanced the antitumor efficacy. The synergetic therapeutic efficacy of GQD/CoSnO 3 heterojunctions through chemotherapy, SDT, and NCT could realize "three-in-one" multimodal oncotherapy to completely eliminate tumors without recurrence. This work provides a paradigm of exploring pH-responsive biodegradable nanozymes as a drug carrier to realize tumor-specific drug release for enhanced SDT and NCT. [ABSTRACT FROM AUTHOR]

[Display omitted] • Efficient photodetector (PD) is gained by multiscale polarity structure optimization. • Detectivity (2.50 × 1012 Jones) and responsivity (0.60 A/W) are observed in the PD. • A denser conductance network provides more photogenerated carrier transport paths. • Bi doping in YMnO 3 realizes an enhanced polarization nearly without changed bandgap. The utilization of ferroelectric photovoltaic effect is thought to be an effective strategy to design novel self-powered photodetectors. However, the low photocurrent output due to the incompatibility between high intrinsic ferroelectric polarization and narrow bandgap is a major disadvantage that restricts photodetection performances. Here, high-efficiency photodetection properties are achieved in a hexagonal Y 1- x Bi x MnO 3 ferroelectric self-powered photodetector using a multiscale polarity structure optimization strategy. Particularly, the photodetector based on Y 0.95 Bi 0.05 MnO 3 (YBMO5) can work in a wide band ranging from ultraviolet to near infrared with the maximum responsivity and detectivity up to 0.60 A/W and 2.50 × 1012 Jones, respectively, with the fast response time of only 0.3/0.4 ms, which are superior to the traditional ferroelectric perovskite photodetectors. The excellent photodetection performances originate from the enhanced photocurrent output, owing to simultaneously achieving big light absorption and robust photogenerated carrier separation and transport. It is demonstrated that Bi doping tunes crystal lattice, domain structure and the interface state, which effectively enhance macroscopic polarity in the condition of nearly unchanged bandgap. Moreover, a denser conductance network of grain boundary is constructed by decreasing grain size, which provides more transport paths for the photogenerated carriers. This work opens up a promising route for the design of high-performance ferroelectric photodetectors. [ABSTRACT FROM AUTHOR]

[Display omitted] • Realizing stabilized antiferroelectric phase and enhanced relaxor behavior in (Na 1-3/2 x Bi 3/2 x)(Nb 1- x Mg x)O 3 ceramics. • The large E b of 78.3 kV/mm, ultrahigh W rec of 10.9 J/cm3 and high η of 83% were achieved in × = 0.06. • x = 0.06 exhibited superior frequency, fatigue, thermal stability and ultrafast discharge rate. Lead-free ceramic-based dielectric capacitors have attracted extensive investigation due to their potential applications in pulsed power devices. However, the main drawback of dielectric ceramics is the relatively low energy storage density. Herein, Bi3+ and Mg2+ with different ionic radius and valence are introduced into antiferroelectric NaNbO 3 matrix to form (Na 1-3/2 x Bi 3/2 x)(Nb 1- x Mg x)O 3 solid solutions, where the antiferroelectric phase is stabilized and the relaxor behavior is also improved. Of particular importance is that a large breakdown strength (E b) of 78.3 kV/mm, an ultrahigh recoverable energy density (W rec) of 10.9 J/cm3 and efficiency (η) of 83% are simultaneously achieved in (Na 0.91 Bi 0.09)(Nb 0.94 Mg 0.06)O 3 ceramic. Moreover, the energy storage properties of (Na 0.91 Bi 0.09)(Nb 0.94 Mg 0.06)O 3 ceramic also reveals superior frequency (1–100 Hz), cycling (100–105) and thermal (30°C–100°C) stability, together with the ultrafast discharge rate (<25 ns). These results demonstrate the NaNbO 3 -based lead-free relaxor antiferroelectric ceramics is a promising candidate for energy storage application. [ABSTRACT FROM AUTHOR]