[en] Highlights: • PMOXA-r-4VP was synthesized by CROP and RAFT polymerization. • PMOXA based coating was formed rapidly on various substrates by UV irradiation. • The PMOXA based coating had excellent stability and antifouling properties. • The antifouling properties of coating could be controlled through UV irradiation. - Abstract: A series of brush copolymers, poly[(2-methyl-2-oxazoline)-random-4-vinylpyridine] (PMOXA-r-4VP), with a variety of compositions was synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization of the poly(2-methyl-2-oxazoline) methacrylate macromonomer (PMOXA-MA) and 4-vinylpyridine (4VP), and then characterized by ¹H NMR spectroscopy and gel permeation chromatography (GPC). The PMOXA-based coatings on the surfaces of glass, silicon, gold and polydimethylsiloxane (PDMS) substrates were then produced by short-time ultraviolet (UV) irradiation of PMOXA-r-4VP. Water contact angel (WCA), ellipsometry, X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and ζ-potential techniques were used to characterize the coatings. The results showed that copolymers can be successfully bonded on the surfaces of glass, silicon, gold, and PDMS substrate. Besides, the PMOXA-based coatings displayed a superior resistance to bovine serum albumin, human blood platelets, Human Umbilical Vein Endothelial Cells adsorption and good biocompatibility. Finally, stability test indicated that the stability of coatings can be improved with the content of the 4VP segment. Furthermore, PMOXA-r_1/2-4VP immobilized surfaces displayed good antifouling property in long-term applications.

[en] Optical vortex beams (VB) have been extensively applied in many fields for their unique features. In this paper, we explore the defocusing intensity of VB modulated by axial symmetry polarization. Combining appropriate polarization order of the modulator, we show that defocusing can result in a spiral structure of intensity distribution, of which the number of spiral arms is determined by the polarization order of the modulator, and the rotation direction of spiral arms depends on the topological charge (TC) of incident beams. The helical structure of defocusing intensity holds a small solid spot when the TC value of VB matches the polarization order number. Therefore, the magnitude of the tested TC can be inferred from the small solid spot distribution, and the sign of the TC can be determined by the rotation direction of the helical intensity. The peculiar phenomena exploited in this paper stimulate the new applications of VB in many fields. (paper)

[en] We developed a facile synthetic method to construct a novel sandwiched coaxial core–shell heterojunction electrode by combining MnO₂ nanoflakes wrapped in Au nanoparticles decorated NiCo₂O₄ nanowires (NW) with carbon fiber cloth (NiCo₂O₄ @Au@MnO₂). XRD, SEM and TEM techniques were used to characterize the structures of NiCo₂O₄@Au@MnO₂ . Electrochemical measurements confirmed that such nanostructured composites possessed an electrochemical capacitance that was higher than that of each individual component due to synergistic effects. The NiCo₂O₄@Au@MnO₂ electrode has extremely high specific capacitance (1906.6 F g^-1 at 1 A g^-1) and excellent cycling stability (92.5% after 10,000 cycles) in a three-electrode system with 6M KOH electrolyte. Furthermore, the performance of an asymmetric supercapacitor of NiCo₂O₄ @Au@MnO₂//AC was further evaluated, and the energy density was 98.3 Wh kg^-1 at a power density of 0.8 W kg^-1 . The excellent electrochemical performance of such nanoscale architecture electrodes provides a new route for developing high-performance supercapacitors with 3D multicomponent heterojunction core-shell structures. (author)

[en] In this paper, we have fabricated poly(N-isopropylacrylamide)-co-polystyrene (PNIPAM-co-PS) nanofibers by electrospinning and explored the possibility to utilize the PNIPAM-co-PS nanofibers to enhance the permeation and uptake of the anticancer drug daunorubicin in drug-sensitive and drug-resistant leukemia K562 cells. Our MTT assay and electrochemical studies demonstrate that PNIPAM-co-PS nanofibers could play an important role in facilitating the cell track and drug delivery to the cancer cells. Meanwhile, the observations of atomic force microscopy (AFM) and confocal fluorescence microscopy indicate that the relevant interaction of the PNIPAM-co-PS nanofibers with bioactive molecules on the membrane of leukemia cell lines could affect the intracellular drug uptake positively and lead to the efficient accumulation of daunorubicin in drug-sensitive and drug-resistant cancer cells

[en] Electrospinning technology can easily produce different shaped fibrous structures, making them highly valuable to various biomedical applications. However, surface contamination of biomolecules, cells, or blood has emerged as a significant challenge to the success of electrospun devices, especially artificial blood vessels, catheters and wound dressings etc. Many efforts have been made to resist the surface non-specific biomolecules or cells adsorption, but most of them require complex pre-treatment processes, hard-to-remove metal catalysts or rigorous reaction conditions. In addition, the stability of antifouling coatings, especially in complex conditions, is still a major concern. In this work, inspired by the interpenetrating polymer network and reinforced concrete structure, an efficient and facile strategy for modifying hydrophobic electrospun meshes and tubes with antifouling zwitterionic hydrogels has been introduced. The resulting products could efficiently resist the adhesion of proteins, cells, or even fresh whole blood. Meanwhile, they could maintain the shapes and mechanical strength of the original electrospun structures. Furthermore, the hydrogel structures could retain stable in a physiological condition for at least 3 months. This paper provided a general antifouling and hydrophilicity surface modification strategy for various fibrous structures, and could be of great value for many biomedical applications where antifouling properties are critical. (paper)

[en] Biomedical applications of living cells have rapidly expanded in many fields such as toxic detection, drug screening, and regenerative medicine, etc. Efficient methods to support cell survival and maintain activity in vitro have become increasingly important. However, traditional cryopreservation for living cell-based applications is limited by several problems. Here, we report that magnetic hydrogel microparticles can physically assemble into a 3D environment for efficient cell preservation in physiological conditions, avoiding any chemical reactions that would damage the cells. Two representative cell lines (loosely and firmly adherent) were tested to evaluate the versatility of this method. The results showed that cell longevity was significantly extended to at least 15 days, while the control cell samples without microparticles quickly died within 3 days. Moreover, after preservation, cells can be easily retrieved by applying a magnet to separate the magnetic particles. This strategy can also inhibit cell over-proliferation while avoiding the use of temperature extremes or toxic cryoprotectants that are essential in cryopreservation. (paper)

[en] The ternary composite photocatalyst Au/Bi₂MoO₆/Bi₂WO₆ has been successfully synthesized by a facile hydrothermal process and microwave-assisted chemical reduction method for the first time. A series of characterization results reveal that Au nanoparticles are uniformly dispersed on the surface of Bi₂MoO₆/Bi₂WO₆ microspheres. The unique photocatalytic performance of the novel composite material is evaluated by the photocatalytic removal of NO gas at ppb levels under visible light irradiation. The photocatalytic removal rate of NO gas in the presence of Au/Bi₂MoO₆/Bi₂WO₆ sample is the highest, which directly attributes to the effective separation of photoinduced charge carriers through the formation of the heterojunction and the Schottky junction at the interface between Au nanoparticles and Bi₂MoO₆ or Bi₂WO₆. Additionally, it is indicated that the h ⁺ and $\cdot <!--\; ???\; -->{\text{O}}_2^{-<!--\; ???\; -->}$ play indispensable role in photocatalytic process by free radicals trapping experiments and the oxidation products of NO gas on the surface of the catalysts are nitrate by drawing the standard curve of total N content in nitrate. Meanwhile, a possible mechanism for the photocatalytic activity enhancement of the Au/Bi₂MoO₆/Bi₂WO₆ composites is proposed. These results demonstrate that the Au/Bi₂MoO₆/Bi₂WO₆ photocatalyst is a promising candidate for indoor air purification under solar light irradiation. (paper)

[en] The effective electromagnetic pulse protection is studied in this paper, first the interference of electromagnetic pulse simulator path is analyzed, including the digital signal processor (DSP) and the discharge circuit of coupling interference and net electricity coupling interference. Using the structure optimization design, the hardware block reinforcement measurement and the setting of open software trap, and the watchdog anti-jamming measures, the interference test is completed such as the central processor core voltage of DSP, input/output (I/O) ports of DSP and the display screen. The experimental results show that the combination of hardware and software protection reinforcement technology is effective, and the interference pulse amplitude of DSP board I/O port and the kernel work voltage are reduced, and the interference duration is reduced from 2 μs to 400 ns. The interference pulse is effectively restrained. (authors)

[en] In order to ensure a safe, accurate and effective operation of the EAST superconducting magnet, a real time early warning system for EAST superconducting magnet quench diagnosis is designed. The system is used to analyze the signal of quench diagnosis and improve the accuracy and reliability of the system. The diagnosis data and related thermal parameters are obtained online from the EAST engineering test database by MDSplus, and the visual analysis of the data can provide the basis for the development of the software. This paper mainly presents the design scheme, basic structure and test results gained using the system. (authors)

[en] Highlights: • The Cu²⁺ and Zn²⁺ could be efficiently removed in the anaerobic methanation system. • The long-term Cu²⁺ and Zn²⁺ removal could be ascribed to the biological-chemical precipitation. • The removal mechanism of Cu²⁺ differed largely from that of Zn²⁺. Copper and zinc are often used as feed additives and frequently detected in swine wastewater. Anaerobic granular sludge (AnGS) plays an important role in high-rate anaerobic methanation biotechnologies which are widely applied to treat swine wastewater. The removal of Cu²⁺ and Zn²⁺ by AnGS was investigated in the batch and continuous systems. The results of batch experiments showed the adsorption by AnGS could be a significant method for Cu²⁺ and Zn²⁺ removal with efficiencies of 99 % and 49 % respectively. The sulfide precipitation mediated by AnGS could be another significant pathway for Zn²⁺ removal with efficiency of 18–27 % in Protein/M²⁺ experiments and 16–46 % in SO₄²⁻/M²⁺ experiments (M²⁺ represents the total concentration of Cu²⁺ and Zn²⁺). The results of continuous experiment showed, with SO₄²⁻/M²⁺ larger than 1.5, the influent Cu²⁺ and Zn²⁺ could be effectively removed in an anaerobic methanation bioreactor and its effluent Cu²⁺and Zn²⁺concentrations were below 1 mg/L and 2 mg/L separately. The main removal mechanism of Cu²⁺and Zn²⁺ in the anaerobic methanation system was that the biological production of sulfide from sulfate was followed by chemical precipitation and reduction. It is helpful for the removal of Cu²⁺ and Zn²⁺ with organic pollutants simultaneously to eliminate environmental risk of swine wastewater.