Coronary artery spasm (CAS) causes serious ischaemic cardiac disease. The hyper-reactivity of vascular smooth muscle cells, which ascribe the up-regulation of endothelin receptor B type, is a key abnormality responsible for the pathological constriction of arteries in CAS. In this study, the nanocarriers were prepared and optimised for the delivery of U0126, which is an inhibitor of the mitogen-activated protein kinase, to treat pathological constriction of arteries. First, cationic amphipathic starch and hyaluronic acid were used in the encapsulation of U0126 to form U0126 nanoparticles (NPs). The shape of the U0126 NPs was spherical with a typical core–shell structure. The size was 94.1 ± 10.2 nm and the zeta potential was −20.3 ± 5.1 mV. Maximal encapsulation efficiencies and drug loading of U0126 in the NPs were 96.2 ± 3.1 and 8.2 ± 2.5%, respectively. U0126 NPs showed very great stability and could perform an effective targeted delivery. An arterial tissue culture model was used in the investigation of anti-constriction. In comparison with treatment with the free drug, the U0126 NPs significantly decreased the effective dosage, enhanced the effect of anti-constriction, and down-regulated the endothelin type B receptor in the culture model. These results suggest that U0126 NPs have a significant potential for the treatment of CAS.

The theory on squeeze film air damping, including Reynolds equation and Poisson equation, has been widely used in theoretical modelling of microelectromechanical systems (MEMS) for many years, but most of the previous studies did not take into account special verification of the theory from numerical simulation. In this Letter, a simulation method is proposed and investigated, and squeeze film air damping is simulated on two basic MEMS structures, the rectangular plate structure, and the circular plate structure. The simulation results are in good agreement with theoretical analysis, and it further proves the correctness of the theory on squeeze film air damping from the point of view of numerical simulation. In addition, the perforated plate is widely used in MEMS, and squeeze film air damping of the perforated plate is also simulated in this Letter. It is concluded that simulation results are better than theoretical analysis, in which the boundary effect of the plate was not considered. Therefore, it is anticipated that the authors simulated method will pave the way to analyse squeeze film air damping for some complex MEMS structures, including the acquisition of air pressure distribution, air damping force and damping coefficient.

In this work, novel flower-like nanoscale zero-valent iron/zinc oxide heterostructure composites were prepared, characterised and used for the enhanced removal of Se(IV) from water. The morphological identification showed that nZVI nanoparticles were uniformly loaded on ZnO nanosheets to minimise their aggregation. Batch experimental results demonstrated that the composites exhibited higher removal efficiency and rate constant on Se(IV) immobilisation than pristine flower-like ZnO and nZVI because of the enhanced dispersion of nZVI nanoparticles. Solution pH, initial Se(IV) concentration as well as interfering ions that affect the removal capacity of Se(IV) were further studied. These results suggested that the composites could be a promising candidate for the potential application in effective remediation of Se-contaminated wastewater.

The mixed-phase BiVO₄ nanosheet with different ratios of solvents was prepared by a one-step hydrothermal method. The viscosity of ethylene glycol helps form a homogeneous thin nanosheet, which can be compared with the microstructure of BiVO₄ with different ratios of solvents (deionised water and ethylene glycol). Also, both XRD and Raman diagrams indicate that the synthesis of BiVO₄ nanosheet constitutes with a mixture of two crystal types. The mixed-phase BiVO₄ possesses higher photocurrent density, smaller electron transport resistance and longer lifetime. Enhanced photoelectrochemical performance can be attributed to the mixed-phase BiVO₄ has a large specific surface area, as well as o-BiVO₄ (orthorhombic BiVO₄) and s-BiVO₄ (monocline BiVO₄), form heterogeneous junction to promote photogenerated carries separation and reduce the recombination of photogenerated electron–hole.

Herein, the authors present a simple and cost-effective silver nanoparticles (AgNPs)-based surface-enhanced Raman scattering (SERS) sensor based on galvanic displacement reaction using AgNO₃ and copper foil as precursors. With the mediation of polyvinyl pyrrolidone (PVP), AgNPs grow in-situ on the surface of copper foil at room temperature. AgNPs-based SERS sensor was prepared with optimised AgNO₃ concentration of 50 mM, the mass ratio of AgNO₃ to PVP of 2:1 and characterised using scanning electron microscopy and X-ray diffraction. As-fabricated SERS sensor exhibited a high Raman signal enhancement factor of 3.5 × 10⁵ in the detection of Rhodamine 6G (R6G). Furthermore, a decent linear relationship for methyl parathion sensing was obtained in the range from 1 × 10⁻⁶ to 1 × 10⁻⁴ M, with an actual detection limit of 1 × 10⁻⁶ M. Recoveries of methyl parathion-spiked lake water samples ranging from 93.64 to 106.16% were obtained, suggesting the feasibility of the SERS sensor. These features demonstrated that the AgNPs-based SERS sensor can potentially be used in sensing a trace amount of chemicals in surface water for environmental protection.

Pectin-conjugated CdS/ZnS core/shell nanocrystals were prepared by using a microwave-assisted approach without the addition of any external ligands. The prepared cubic phase CdS/ZnS nanocrystals were uniform and mono-dispersed with sizes of 6–9 nm. The charge and long-chain structure of pectin molecules effectively prevented the aggregation of CdS/ZnS nanocrystals. In addition, pectin molecules have multiple functional groups, such as O–H, C=O, and COO⁻, which could conjugate with the surface of samples to control the growth of CdS/ZnS nanocrystals. Thermogravimetric analysis provided evidence that the obtained products are inorganic–organic hybrid materials. Based on the analysis of ultraviolet–visible spectra, it was found that the formation of ZnS shell led to a red-shift and an enhancement of absorption of CdS/ZnS nanocrystals compared with that of CdS. Photocatalytic activity of CdS/ZnS nanocrystals was monitored by the degradation of Rhodamine B under visible light irradiation. The presence of ZnS shell inhibited photo-corrosion and photo-dissolution of CdS nanocatalyst, thus resulting in a significant enhancement of photocatalytic activity and stability.

The present study was carried out to determine the effect of plant extract of Syzygium cumini and their silver nanoparticles (AgNPs) against the poultry pathogens. The plant extract was prepared in methanol, ethanol, ethyl acetate, chloroform, and n-hexane. The results of phytochemical screening showed that the leaf extract of S. cumini have medicinally important phytochemical constituents. In the present study, AgNPs were synthesised by using an extract of S. cumini. Synthesised AgNPs were confirmed by Fourier-transform infrared spectroscopy, ultraviolet–visible, and scanning electron microscopy. A surface plasmon resonance peak in absorption spectra showed absorption at 419 nm. The synthesised nanoparticles were found spherical in shape with the diameter range of 30–120 nm. The antimicrobial activity of crude extract and AgNPs was checked against the poultry bacterial pathogens by the agar well diffusion method. The authors’ findings revealed that the crude extract and AgNPs have promising activities against all the test pathogens. It is concluded that the bioactive compounds from the extract of S. cumini and extract-mediated AgNPs can be significantly used as an alternate poultry medicine to replace the available antibiotics, which have adverse side effects.

In this contribution, polyvinyl pyrrolidone capped copper nanoclusters (PVP-Cu NCs) were synthesised through a one-pot route possessing the advantages of rapidness and environmental friendliness. Also, the optical characteristics of the as-prepared Cu NCs were characterised using fluorescence spectroscopy, UV–vis absorption spectroscopy. The structure and composition were studied through Fourier transform infrared, transmission electron microscopy, X-ray photoelectron spectroscopy. It exhibited good water solubility, excellent photo stability, and resistance to sodium chloride. The Cu NCs revealed blue fluorescence and displayed excitation-dependent fluorescence characteristics. More importantly, the fluorescence intensity of PVP-Cu NCs was linearly quenched in the range of 5–80 μM (concentrations of fluazinam) and the detection limit was 0.98 μM. Finally, the fluorescence sensor was successfully employed to detect fluazinam in natural water samples.

A graphene rotational switch (GRS) is presented utilising vacancy defect and nitrogen (N) doping in armchair graphene nanoribbon (AGNR). By twisting AGNR at different angles in the suggested device, its conductivity can be controlled. Based on the simulation results it is indicated that the electronic parameters such as current, transmission, local density of state, and conductance of the suggested GRS are also associated with the width of AGNR, selection of defect or doping and its location in the AGNR. Furthermore, the results show the dependency of the proposed GRS to the voltage. In this Letter, a monotonic increase or decrease in the current between the minimum and maximum angles in the corresponding bias voltage is defined as the proper switching behaviour. The assumed defect or doping is replaced by three locations with three various widths and five different twist angles of AGNR, in different analysed modes. Devices have better switching behaviour so the range of I _max/I _min is within 37–1076 among all the modes. The best three modes are the perfects, N doping near the AGNR edge and the vacancy defect in the centre of the deformation region of AGNR in the width of 9, 10 and 11w, respectively.

Flexible and foldable microcomponents are highly desirable for energy devices. In this work, flexible asymmetric micro-capacitor (AMC) is fabricated by using uniform Ag/Bi₂S₃ (or Bi₂S₃) nanoflowers, active carbon and carbon fibres are used as positive material, negative material and current collector, respectively. On one hand, the areal capacitance of Ag/Bi₂S₃ electrode has increased by more than 6 times than Bi₂S₃, and 86 and 68% of capacitances are retained for Ag/Bi₂S₃ and Bi₂S₃ electrodes after 4000 cycles, respectively. On the other hand, Ag/Bi₂S₃-based AMC has an energy density of (0.0134 mWhcm⁻³) 4.36 times higher than Bi₂S₃-based one (0.0025 mWhcm⁻³); after 4000 cycles, 84 and 33% of capacitances are retained for Ag/Bi₂S₃- and Bi₂S₃-based AMCs, respectively. The improved performances are mainly attributed to the enhanced electrical conductance by Ag loading (Bi₂S₃: 21.898 Ω; Ag/Bi₂S₃: 4.5643 Ω). Most importantly, the AMC is flexible and foldable, which is promising to conveniently apply in complicated energy devices, production for practical applications.

Amphiphilic block copolymer poly(ethylene oxide)-b-poly(tert-butyl acrylate) (PEO₄₅-b-PtBA₃₅) from atom transfer radical polymerisation was hydrolysed to varying degrees through adjusting hydrolysis time. And the hydrolysis product poly(ethylene oxide)-b-poly(acrylic acid) (PEO₄₅-b-PAA₃₅) was obtained and used as a template to synthesise nanostructured poly(o-phenylenediamine) (PoPD). The influence of hydrolysis degrees of PEO₄₅-b-PAA₃₅ on the size and electrochemical properties of PoPD was investigated. Results showed that the PoPD particles have uniform sizes, and their size could be tuned with the hydrolysis degree of PEO₄₅-b-PAA₃₅. The average diameter and length of PoPD were less than 86 and 135 nm, and the size of these particles was increased with the increase of hydrolysis degree of PEO₄₅-b-PAA₃₅. Electrochemical characterisation proves that the particle with a smaller size had a better electrochemical activity. When the hydrolysis time was 12 h, the PoPD had the best specific capacitance compared with other samples. The discharge specific capacitance calculated by chronopotentiometric test of this sample is reached 809 F·g⁻¹ at the current density of 0.5 A·g⁻¹.

The Cu-doped TiO₂ plate-like particle was synthesised via using the layered H_1.07Ti_1.73O₄·H₂O (HTO) plate-like particle as a precursor. The Cu-doped TiO₂ particle consists of nanocrystals and holes, and these nanocrystals are oriented at []-crystal-axis direction. Firstly, the HTO particle was treated in a copper acetate solution, forming Cu²⁺-exchanged HTO plate-like particles. And then Cu²⁺-exchanged HTO in situ transformed into Cu-doped TiO₂ via heat-treating and further acid washing. The Cu-doped TiO₂ particle has a stronger absorption in the visible light region of 400–800 nm and the visible photocatalytic H₂ production activity.

Bismuth (Bi) micro, nanoparticles are an emerging non-noble metal catalyst, but they are prone to agglomeration due to the large surface energy, which weakens its function and limits its application. Bi nanoparticles were immobilised on activated carbon by the impregnation reduction method to prevent the agglomeration. The prepared material exhibited enhanced photocatalytic efficiency compared to Bi nanoparticles alone. The origin of photocatalytic efficiency enhancement was investigated. It was attributed to the large specific surface area of the composite and more exposed active sites. This research proposes a new strategy for the photocatalytic application of Bi nanoparticles.

This Letter reports the high gas response for hydrogen gas (H₂) in Pd/TiO₂/Si/Al based metal-oxide semiconductor (MOS) sensor. Titanium oxide (TiO₂) thin film deposited on the p-type silicon (Si) substrate is used as the gate oxide of the MOS sensor. The surface morphology of thermally evaporated TiO₂ thin film is investigated for the film structure using atomic force microscopy and scanning electron microscopy. The proposed MOS sensor characterised by capacitance–voltage (C–V) and conductance–voltage (G–V) measurements under exposure of different concentration of H₂ gas at room temperature in the ambient-air atmosphere. The maximum gas response of 65% calculated from the change in capacitance and 84% calculated from the change in conductance are obtained for the exposure of 4% of H₂ gas. The obtained maximum gas responses are highly promising for low concentration detection of hydrogen gas (4%) using the fabricated MOS sensor operated at room temperature under zero bias voltage condition.

Doping nanoparticles into liquid crystal (LC) systems can effectively improve the electro-optical (E-O) properties of LCs. The authors introduced three types of (cubic, octahedral, and rhombic dodecahedral) Au nanocrystals (NCs) into a nematic LC 4-cyano-4′-n-pentylbiphenyl (5CB) and investigated the facet-dependent Au NCs in improving the E-O properties of 5CB. The surface energies of Au facets decreased in the order {110}>{100}>{111}. The improvement in the E-O properties of LC is related to the interaction between LC and different exposed crystal planes of dopants. Dodecahedral Au NCs, exposing {110} facets, are the most effective in improving the E-O properties because of their highest surface energy, resulting in a 30.15% reduction of the threshold voltage (V_th) and a 29.08% of the saturation voltage (V_sat) at a doping concentration of 0.4 wt%. The Au NCs trapped impurity particles. The screening effect could be suppressed, and the electric field could be strengthened, resulting in outstanding E-O properties. This work provides a novel way to enhance the E-O properties of LC molecules by doping with noble metal nanomaterials, thus improving their potential applications in energy-saving LC displays.