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The occurrence of membrane fouling has resulted in limited wastewater treatment applications. The development of superhydrophilic-underwater superoleophobic materials has received significant attention owing to their good anti-fouling properties. However, to fabricate such materials need costly regents and tedious steps. Thus, developing a one-step process to prepare a low-cost material for oil/water separation is still desired. In this study, bio-inspired from an arachnid, inorganic carbon nanotube stainless steel meshes (CNT@SSMs) having superhydrophilic-underwater superoleophobic and excellent anti-fouling properties and a unique fiber structure were fabricated via a one-step thermal chemical vapor deposition method. The CNT@SSMs had a small pore size enabling a high water flux of 10,639 L m−2h−1 and the separation of oily wastewater, including various emulsions, at a high rejection ratio of >98.89%. As a result of its excellent chemical stability under high temperatures, a broad pH range, and saline environments, the CNT@SSM has the potential to be used in extreme conditions. In summary, these CNT@SSMs are easy to fabricate and are low-cost as a result of inexpensive reagents involved. Moreover, these novel superwetting membranes are promising candidates for treatment of hazardous oily wastewater.

Hydrothermal degradation was used to pretreat terylene with an aim of noticeably improving the yield of fermentable monomers: terephthalic acid (TPA), mono (2- hydroxyethyl) terephthalic acid (MHET), bis-hydroxyethyl terephthalate (BHET), and ethylene glycol (EG). After 0.5 h of reaction time at 180 °C, hydrothermal degradation with ammonia led to almost complete conversion of the terylene to TPA, MHET, BHET and EG, which were then transformed by Taonella mepensis WT-6 to bacterial cellulose (BC). Furthermore, the optimum fermentation conditions with the maximum BC yield were 5.0 g/L yeast extract, 30.0 °C, pH 9.0, 8.0% inoculum, and hydrolysate TOC (5.02 g/L). Additionally, mechanical and thermal analysis revealed that the properties of BC produced from TAH medium were similar to those of BC produced with HS medium. Considering the substantial amount of global terylene waste being produced, this study provides an alternative solution for the biosynthesis of BC.

The ability to control the potential landscape in a medium of interacting particles could lead to intriguing collective behavior and innovative functionalities. Here, we utilize spatially reconfigurable magnetic potentials of a pinwheel artificial spin ice structure to tailor the motion of superconducting vortices. The reconstituted chain structures of the magnetic charges in the artificial pinwheel spin ice and the strong interaction between magnetic charges and superconducting vortices allow significant modification of the transport properties of the underlying superconducting thin film, resulting in a reprogrammable resistance state that enables a reversible and switchable vortex Hall effect. Our results highlight an effective and simple method of using artificial spin ice as an in-situ reconfigurable nanoscale energy landscape to design reprogrammable superconducting electronics, which could also be applied to the in-situ control of properties and functionalities in other magnetic particle systems, such as magnetic skyrmions., Comment: To appear in Nano Letters

Chiral transcription and enantioselective separation have garnered significant research interests and showed potential for a broad range of practical applications. Here, we present a novel and facile strategy for chiral templating and enantiomers resolution by coating metal-ion-mediated l -phenylalanine derivatives (LPF/M) with graphene oxide (GO) via simply mixing. The LPF/M hydrogels precipitate from the liquid by encapsulation of GO through coordination interactions and hydrogen bonds, making heterogeneous transfer and separation possible. The chirality inversion of the internal LPF/M nanostructure could be triggered by different addition of metal ions, which further provides means for controlled chiral transfer of guest molecules on the outer GO surfaces as demonstrated in the transcription of thioflavin T (ThT) and 3-aminopyridine (AP) at the supramolecular level. Changing the metal ions also provides control over enantiomer selectivity with outstanding efficiency and reproducibility, as revealed by the separation of racemic mixtures of phenylanine (>98%), lysine (>96%), and histidine (>97%). In addition, the resultant hybrid materials exhibit excellent environmental stability and reusability (more than 20 times) with significant separation efficiency. More importantly, the GO-coated LPF/M could determine the enantiomeric composition of various chiral substrates. The proposed strategy opens up a promising avenue for practical chiral separation application.

BACKGROUND: Lactic acid (LA) is a valuable industrial chemical with wide applications. Presently, the demand for optically pure l‐LA has grown considerably as a result of its applications in the food and pharmaceutical industries, and biodegradable polylactic acid production. The production of l‐LA from food waste (FW) has been discussed in some studies; however, most fermentation is performed under sterile conditions and with the addition of specific lactic acid bacteria. Completely autoclaving organic solid wastes is difficult and economically unfeasible. The aim of this work was to investigate pilot‐scale LA production from FW under sterile and nonsterile conditions. RESULTS: When FW was fermented without sterilization and inoculation, the maximum yield of LA was 0.43 g LA g–¹ total solid (TS) and the proportion of l‐LA was only ≈50%. A newly isolated strain, Lactobacillus paracasei subsp. paracasei 2, which was isolated and identified from FW, was used to improve the proportion of l‐LA in total LA. When nonsterile FW was inoculated with this strain, the proportion of l‐LA increased to 72.3%. After FW was sterilized and inoculated with this strain, the proportion of l‐LA was 98.6% and 98.8% under intermittent and real‐time regulation of pH level, respectively. The maximum LA yield could increase to 0.55 g LA g–¹TS. CONCLUSION: Pilot‐scale LA production from FW was determined by comparing the isomer purity of l‐LA between sterilization and nonsterilization and between inoculation and noninoculation, which provided an important strain and fermentation type for production of high concentration of l‐LA. © 2020 Society of Chemical Industry

Clay often has severe detrimental impacts on cement-based materials. Therefore, it is necessary to investigate the mechanism causing the deterioration to improve the service life of cement-based materials. Based on accurate dimensional analysis, a mechanism that influences clay is proposed: the intercalation of the side chains of superplasticizer molecules in the interlayer space of the clay. To lessen this harmful effect, a new clay-resistant admixture (CRA) possessing cationic groups of small molecular size was synthesized through a novel dimensional design. The length and width of the side chains of this superplasticizer molecule were 9.50–17.50 and 0.25–0.40 nm, respectively, with a radius of ~3.74 nm in solvent, which is larger than the interlayer spacing of montmorillonite (i.e. 1.09–2.14 nm). The longitudinal and latitudinal lengths of the CRA molecule were 0.468 and 9.456 nm, respectively, ensuring intercalation in the interlayer of montmorillonite. The increase in interlayer spacing of the clay was 0.364 nm following addition of polycarboxylate superplasticizer (PCE) plus CRA and 0.632 nm following addition of PCE, which suggests that the CRA plays the role of a ‘sacrificial agent’ that is preferentially intercalated into the interlayer space of clay to further prevent the side chains of the superplasticizer molecules from entering the interlayer. The aim of this study was to propose a suitable means of synthesizing a new CRA to address the impact of clay through dimensional design and mechanism analysis, which contributes to the theoretical study and technological improvement of cement-based materials.

To broaden the application of oxime ester and obtain a photoinitiating system with high performance in visible light photopolymerization, we prepared the two arylaminocarbazole oxime ester (CZ–OXE), OXE1 and OXE2, with visible absorption. The multicomponent initiation systems of OXE as one of the components were evaluated in visible photopolymerization. Synergism between OXEs and diaryliodonium salt (ION), N-vinylcarbazole (NVK), ethyl 4-dimethylamino benzoate (EDB), and triphenylphosphine (TPP) were experimentally studied via steady state photolysis and fluorescence quenching. The thermodynamic feasibility for electron transfer reaction in photoinitiating systems was confirmed by cyclic voltammetry experiments. Electron spin resonance techniques proved the production of active species in the systems. Polymerization experiments under a 405 nm light source showed that the two-component initiation system OXEs/ION was more efficient than the one-component initiator OXEs. Similarly, three-component OXEs/ION/co-initiator photoinitiating systems are more efficient than OXEs/ION systems.

Although numerous fluorescent probes are designed to detect the pH value in the past decades, developing fluorescent probes for extreme alkalinity (pH > 14) detection in aqueous solution is still a great challenge. In this work, we utilized 1H-imidazo[4,5-f][1, 10] phenanthroline (IP) group as the recognition group of hydroxyl ion and introduced two triethylene glycol monomethyl ether groups to improve its solubility. This IP derivative, BMIP, possessed good solubility (25 mg/mL) in water. It displayed high selectivity toward extreme alkalinity (pH > 14) over other ions and pH (from extreme acidity to pH = 14). From 3 to 6 mol/L OHˉ, the exact concentration of OHˉ could be revealed by BMIP and the whole detection process just needed a short time (≤ 10 s). Meanwhile, it exhibited good anti-interference ability and repeatability during the detection process. Through optical spectra and NMR analysis, its detection mechanism was proved to be deprotonation by hydroxyl ion and then aggregation-induced enhanced emission. Our study presents a new basic group based on which researchers can develop new fluorescent probes that can detect extreme alkalinity (pH > 14) in aqueous solution.

The mechanism of deactivation of MnOx/TiO2 is studied. The MnOx/TiO2 catalyst prepared by co-precipitation method has poor stability, the NO conversion decreased to about 50% after 100 h denitrification. Catalyst activity and physicochemical properties of the catalyst before and after SCR denitrification were compared and analyzed through BET, XRD, SEM, which indicated that dispersion of active sites and surface area of catalyst were decreased after 100 h denitrification. Catalyst activity and surface chemical compositions were investigated by XPS, H2-TPR, NH3-TPD, which shown that content of Mn3+ and chemisorbed oxygen on the surface decreases. The different active sites of catalyst and adsorption characteristics of reacting gases (NH3 and NO) over catalyst before and after denitrification was investigated through in-situ DRIFT. It was found that NO is more easily adsorbed on the surface of catalyst than NH3 and form nitrate. The nitrate that did not participate in the reaction gradually accumulate on the surface of the catalyst, which inhibits the adsorption of NH3. This is the main reason for the deactivation of the catalyst.

In this paper, we propose a method to analytically solve some types of DC lumped-parameter equivalent circuit models for solar cells with S-shaped I-V characteristics measured under illumination. Based on the models proposed previously by other authors, we present the set of equations describing solar cell’s terminal current and voltage, derive the analytical solutions of I-V characteristics, and give discussions about the effects from the model parameters on solar cells’ I-V characteristics. The comparisons between the proposed solutions and the least square method results illustrate that the solution calculation scheme is not only both accurate and efficient, but also valid in the whole operation regime of solar cells especially for the S-shaped kink in the first quadrant. Finally, the solutions are validated by the reconstructed experimental data to demonstrate that they can be adopted in the practical applications of solar cells. As a result, the feature of the proposed solutions can decrease computation complexity, ease the extraction process of the solar cells’ model fitting parameters, and increase simulation accuracy.

Due to the great similarity to the natural extracellular matrix and minimally invasive surgeries, injectable hydrogels are appealing biomaterials in cartilage and bone tissue engineering. Nevertheless, undesirable mechanical properties and bioactivity greatly hamper their availability in clinic applications. Here, we developed an injectable nanocomposite hydrogel by in situ growth of CaP nanoparticles (ICPNs) during the free-radical polymerization of dimethylaminoethyl methacrylate (DMAEMA) and 2-hydroxyethyl methacrylate (HEMA) matrix (PDH) for bone regeneration. The ICPNs are self-assembled by incorporation of poly-l-glutamic acid (PGA) with abundant carboxyl functional groups during the formation of carboxyl–Ca2+ coordination and further CaP precipitation. Furthermore, the carboxyl groups of PGA could interact with the tertiary amines of DMAEMA fragments and thus improve the mechanical strength of hydrogels. Upon mixing solutions of DMAEMA and HEMA bearing PGA, Ca2+, and PO43–, this effective and dynam...

A pilot-scale multilevel contact oxidation reactors system, coupled with saran lock carriers, was applied for the treatment of poultry farm wastewater. The removal efficiencies of CODcr, ammonia, and the total nitrogen as well as the elimination performance of CODcr and total nitrogen along the three-level contact oxidation tanks under six designed operational models were investigated. Based on the performance of the nitrogen removal of the saran lock carriers and the distribution of anoxic–aerobic interspace under the suitable operation model, the mechanism of nitrogen removal of the system was also explored. The results revealed that the intermittent aeration under parallel model is the most suitable operation model, while the removal efficiencies of CODcr, ammonia, and the total nitrogen were 86.86%, 84.04%, and 80.96%, respectively. The effluent concentration of CODcr, ammonia, and the total nitrogen were 55.6 mg/L, 8.3 mg/L, and 12.0 mg/L, which satisfy both the discharge standard of pollutants for livestock and poultry breeding industry (GB 18596–2001) and the first grade of the integrated wastewater discharge standard (GB 8978–1996). Moreover, the mechanism for the nitrogen removal should be attributed to the plenty of anoxic–aerobic interspaces of the biofilm and the three-dimensional spiral structure of the saran lock carriers, where the oxygen-deficient distribution was suitable for the happening of the simultaneous nitrification and denitrification process. Therefore, the multilevel contact oxidation tanks system is an effective pathway for the treatment of the poultry farm wastewater on the strength of a suitable operation model and novel carriers.

Fructosyltransferases have been used in the industrial production of fructooligosaccharides (FOS). However, it is still not possible to explain the difference in FOS production based on the variations observed in the FOS synthesizing enzymes of A. niger. In the present study, a novel fructosyltransferase (FT-A) from A. niger TCCC41686 with high FOS synthesis ability was characterized. The FT-A gene was obtained and expressed in Pichia pastoris. A homology model of FT-A showed that the changes of residues identified outside the conserved domains were found to have an effect on its characteristics and its FOS-synthesis capacity. The optimal activity of the recombinant FT-A was observed at 50 °C and pH 6.0, and it was stable below 50 °C and over the range of pH 3.0–11.0. The Km and Vmax values of FT-A were 151.13 g L−1 and 6.55 g L−1 min−1, respectively. The production of FOS using the recombinant FT-A remained above 60% during 50–80 min of synthesis based on sucrose as substrate. The novel fructosyltransferase (FT-A) investigated in this study can potentially be applied for the efficient industrial production of FOS. The results also provide more valuable information for explaining the relationship between the structure and function of the FT-A.

A novel layer by layer (LbL) assembled structure with phosphorylcholine groups was fabricated to improve the hemocompatibility of paclitaxel/chitosan (PTX/CS) nanofibers (NF) coatings The random copolymers with phosphorylcholine groups poly (2‑methacryloyloxy-ethylphosphorylcholine‑co‑methacrylicacid) (PMAs) were synthesized through free radical polymerization and then first PMA layer formed on PTX/CS NF coatings via electrostatic interactions. After that CS polycation and PMA polyanion thin films LbL formed on PTX/CS NF coatings. The LbL structure was confirmed by X-ray photoelectron spectroscopy (XPS) and water contact angle. The drug release in vitro indicated that the PMA modified PTX/CS NF coatings (PTX/CS-PMA NF coatings) showed a sustained slower release of PTX drug. The LbL coatings containing phosphorylcholine groups could significantly reduce proteins adsorption, platelets adhesion and cell adhesion. They showed a lower platelet (about 6%) and protein (30–40%) (bovine serum albumin, BSA; bovine plasma fibrinogen, Fg) adhesion. Meanwhile, the adhesion of human umbilical vein endothelial cells (HUVECs) was also found reduced. These results demonstrate that the preparation of PMA modified coatings is a simple strategy to improve the hemocompatibility of PTX/CS NF coatings, has good potential for application in blood-contacting materials and devices. Statement of significance We develop a simple method to improve the hemocompatibility of paclitaxel/chitosan (PTX/CS) nanofibers (NF) coatings, which can significantly reduce the protein adsorption, and the adhesion of cells and platelets. Using layer by layer (LbL) assembly with PMA polyanion and CS polycation, multilayered PMA/CS films formed on the PTX/CS NF coatings. The X-ray photoelectron spectroscopy (XPS) and water contact angle characterization demonstrated that a cell outer membrane mimetic structure was formed on the PTX/CS NF coatings. The hemocompatibility of modified surface was significantly improved as shown by 94% adhesion suppression for platelets and 60–70% adsorption suppression for bovine plasma fibrinogen (Fg) and bovine serum albumin (BSA). The drug release in vitro indicated that the PMA modified PTX/CS NF (PTX/CS-PMA) coatings had a sustained drug release. Thus this paper provides a facile method for fabricating cell outer membrane mimetic structure which can improve hemocompatibility of blood-contacting material surfaces.

Tungsten-based coatings without TiC addition (TiC-free) and with 1.5 wt% TiC addition (TiC-doped) were fabricated by supersonic atmospheric plasma spraying (SAPS) technique, respectively. The as-sprayed coatings were then irradiated by laser. The results showed that the as-sprayed coatings were mainly composed of lamellar structure. TiC phase located mainly at lamellar gaps of the as-sprayed TiC-doped coating with a morphology of strip filled the gaps. The as-sprayed TiC-doped coating exhibited dense structure, lower porosity, reduced oxygen content and higher thermal conductivity as compared with the as-sprayed TiC-free coating. The as-irradiated coatings could be divided into remelted zone, un-remelted zone and/or mixing zone. Cracks were more easily formed in the as-irradiated TiC-free coating than in the as-irradiated TiC-doped coating. The stripped TiC phase in the as-sprayed TiC-doped coating changed into quasi-spherical/spherical ones in the remelted zone of the irradiated coating and distributed along the tungsten grain boundaries. The averaged tungsten grain size in the remelted zone of the as-irradiated TiC-doped coating was about 5.4 μm and that of the as-irradiated TiC-free coating was about 14.8 μm. There were about 96 wt% α(W) and about 4 wt% γ(W) existed in the remelted zone near the surface of the as-irradiated TiC-free coating. Only α(W) could be received in the remelted zone far from the surface of the as-irradiated TiC-free coating and the remelted zone of the as-irradiated TiC-doped coating. There were no obvious diffraction peaks for γ(W) could be indexed from the XRD patterns for the as-irradiated TiC-doped coating. The ability of the as-sprayed TiC-doped coating to resist laser irradiation was greater than the as-sprayed TiC-free coating, mainly attributing to the higher thermal conductivity of the as-sprayed TiC-doped coating and the refinement effect of TiC particles in the as-irradiated TiC-doped coating.

In recent decades, metasurfaces have emerged as an exotic and appealing group of nanophotonic devices for versatile wave regulation with deep subwavelength thickness facilitating compact integration. However, the ability to dynamically control the wave–matter interaction with external stimulus is highly desirable especially in such scenarios as integrated photonics and optoelectronics, since their performance in amplitude and phase control settle down once manufactured. Currently, available routes to construct active photonic devices include micro-electromechanical system (MEMS), semiconductors, liquid crystal, and phase change materials (PCMs)-integrated hybrid devices, etc. For the sake of compact integration and good compatibility with the mainstream complementary metal oxide semiconductor (CMOS) process for nanofabrication and device integration, the PCMs-based scheme stands out as a viable and promising candidate. Therefore, this review focuses on recent progresses on phase change metasurfaces with dynamic wave control (amplitude and phase or wavefront), and especially outlines those with continuous or quasi-continuous atoms in favor of optoelectronic integration.

Bovine serum albumin (BSA) microspheres were prepared through a facile and low-cost route including a high-speed dispersion of BSA in cross-linking solution followed by spray drying. Interestingly the as-prepared BSA microspheres possess unique blue-green, green, green-yellow, and red fluorescence when excited by specific wavelengths of laser or LED light. The studies of UV-visible reflectance spectra and fluorescence emission spectra indicated that four classes of fluorescent compounds are presumably formed during the fabrication processes. The formation and the potential contributors for the unique green and red autofluorescence were also discussed and proposed though the exact structures of the fluorophores formed remain elusive due to the complexity of the protein system. The effect of spray-drying conditions on the morphology of spray-dried samples was investigated and optimized. FTIR was further employed to characterize the formation of the functional groups in the as-prepared autofluorescent microspheres. Good in vitro and in vivo biocompatibility was demonstrated by the cytotoxicity test on the A549 cancer cells and tissue histological analysis, respectively. The autofluorescent BSA microspheres themselves were then applied as a novel tracer for convenient tracking/modeling of the biodegradation of autofluorescent BSA microspheres injected into mouse model based on noninvasive, time-dependent fluorescence images of the mice, in which experimental data are in good agreement with the proposed mathematical model. All these studies indicate that the as-developed protein microspheres exhibiting good biocompatibility, biodegradability, and unique autofluorescence, can significantly broaden biomedical applications of fluorescent protein particles.

Transphosphatidylation catalyzed by phospholipase D has gained increasing attention for producing phosphatidylserine (PS), which can be used in functional food and medicine. In this study, we investigated the effects of six signal peptides on the secretion of PLD (PLDsa) from Streptomyces antibioticus TCCC 21059 in the food-grade GRAS bacterium Bacillus subtilis. It indicated that the optimal signal peptide DacB with an Ala-X-Ala sequence motif at the C-terminus showed the highest secretory expression ability, resulting in increased production of 2.84 U/mL PLDsa. Then PLDsa was immobilized on the epoxy-based carriers, and one of these carriers allowed PLDsa loading of up to 2.7 mg/g. The immobilized PLDsa was more stable over a wide range of pH value (4.5–7.5) and temperature (16 °C–60 °C) than free PLDsa. Subsequently, the synthesis of PS from soybean phosphatidylcholine (PC) was carried out in purely aqueous solution using immobilized PLDsa, leading to a high yield of 65%. The immobilized PLDsa catalyst maintained a relative PS production of 60% after 5 recycles. Notably, the use of toxic solvent was completely eliminated in the whole process, which would be more profitable for the application of PS.

High-efficiency optoelectronic devices require materials with suitable band gap, excellent carrier mobility, strong light-matter interaction, and high thermal- and photostability. Herein, we report two layered materials of group VI, namely, $\mathrm{Se}{\mathrm{S}}_{2}$ and $\mathrm{Te}{\mathrm{S}}_{2}$, which meet all those desired criteria. Both materials are stable with 1T-$\mathrm{Mo}{\mathrm{S}}_{2}$-like structure, and exhibit in-direct gap semiconducting feature and possess extraordinary electronic transport properties with isotropic carrier mobilities outperforming their $\mathrm{Mo}{\mathrm{S}}_{2}$ analog. Using the $GW$ approach for determining the quasiparticle electronic structure and Bethe-Salpeter equation accounting for the many-body excitonic effects, the optical properties of both materials have been identified. We find that exciton effects are significant in both materials that is characterized by the large binding energy of 0.66 and 0.84 eV for monolayer $\mathrm{Se}{\mathrm{S}}_{2}$ and $\mathrm{Te}{\mathrm{S}}_{2}$, respectively. The absorption edges lie in the optimal energy window of $1.0\text{--}1.5\phantom{\rule{0.28em}{0ex}}\mathrm{eV}$, which enables strong photoabsorption covering the whole visible-light region. Finally and importantly, we demonstrate that the in-direct nature of those materials can be violated by capping them with 2H-$\mathrm{Mo}{\mathrm{S}}_{2}$ to form a van der Waals heterostructure, while keeping the gap in the energy favorable region. Those physical and optical characteristics make few-layer $\mathrm{Se}{\mathrm{S}}_{2}$ and $\mathrm{Te}{\mathrm{S}}_{2}$ highly appealing for room-temperature light-emitting devices and, particularly, solar harvesting devices.

The rapid development of nanotechnology has provided new strategies for the treatment of tumors. Nano-scale hydroxyapatite (HAP), as the main component of hard tissues in humans and vertebrates, have been found to specifically inhibit tumor cells. However, achieving controllable synthesis of HAP and endowing it with cancer cell-targeting properties remain enormous challenges. To solve this problem, we developed polyacrylic acid-coordinated hydroxyapatite nanoparticles (HAP–PAA) and further chemically grafted them with folic acid (HAP–PAA-FA) for cancer treatment in this study. The nucleation sites and steric hindrance provided by the PAA greatly inhibited the agglomeration of the nanoparticles, and at the same time, the excess functional groups further modified the surface of nanoparticles to achieve targeting efficiency. The spherical, low-crystallinity HAP–PAA nanoparticles exhibited good tumor cell lethality. After grafting the nanoparticles with folic acid for molecular targeting, their cellular uptake and specific killing ability of tumor cells were further enhanced. The HAP–PAA-FA nanoparticle system exerted a regulatory effect on the tumor microenvironment and had good biological safety. All the above results indicate that this research will broaden the application of hydroxyapatite in tumor treatment.

Transdermal drug delivery of propranolol hydrochloride (PRH) is promising for the treatment of infantile hemangioma (IH). Clinically used PRH hydrogel fails to reach the deep IH for complete recovery. In this study, the PRH-loaded cubic nanoparticles (CNPs) were prepared to promote the transdermal effect of PRH. A remote drug loading method was developed to prepare the PRH-CNPs. For the traditional passive drug loading method, the largest encapsulation efficiency (EE%) was around 50%. The remote drug loading was performed by increasing the pH of the mixture of blank CNPs and PRH solution. The optimal PRH-CNPs showed an EE% of 90.15 ± 2.44% at pH 8.5. The permeation of the PRH solution was poor while the PRH-CNPs showed greatly enhanced skin permeation. It was found that smaller-sized PRH-CNPs contributed to increased skin permeation and retention. In addition, the PRH-CNPs had higher cytotoxicity towards the EOMA cells when compared with the PRH solution. During storage for 1 month, the PRH-CNPs kept stable size distribution, pH, and EE%. In conclusion, results of this study suggested that the PRH-CNPs could be a potential candidate for the treatment of the IH by transdermal delivery.

We present a nanoparticle size-separation device based on a nanofluidic rocking Brownian motor. It features a ratchet-shaped electrostatic particle potential with increasing barrier heights along the particle transport direction. The sharp drop of the particle current with barrier height is exploited to separate a particle suspension into multiple sub-populations. By solving the Fokker--Planck equation, we show that the physics of the separation mechanism is governed by the energy landscape under forward tilt of the ratchet. For a given device geometry and sorting duration, the applied force is thus the only tunable parameter to increase the separation resolution. For the experimental conditions of 3.5 V applied voltage and 20 s sorting, we predict a separation resolution of $\sim 2$ nm, supported by experimental data for separating spherical gold particles of nominal 80 and 100 nm diameters., 5 pages, 4 figures plus supplemental material

Nanomicelles, by virtue of their prominent biocompatibility, degradability, and ability to solubilize hydrophobic drugs, have been widely used as the most effective delivery platform for anticancer drugs. However, undesirable drug-loading capacity, unfeasible modification, poor in vivo stability, and intratumoral penetration remain to be addressed. Herein, we introduce a novel core/shell PEGylated poly(glycerol sebacate) (PEGS)/hydroxyapatite (HA) hybrid nanomicelle based on a unique triblock PEGS substrate with functional carboxyls in terminals and free hydroxyls as pendant groups. The hydrophobic doxorubicin (DOX) can be controllably encapsulated in the core of nanomicelles via hydrogen bonding, and ensuing in situ mineralization of HA occurs as a shell layer with the electrostatic effect between the carboxylate radical (COO-) and calcium ion (Ca2+). Through optimizing the coordination of PEGS nanomicelles and HA mineralization, 20-30 nm spherical nanoparticles can be formed with considerable drug loading (0.38 mg DOX/1 mg nanoparticles) and a sensitive pH-responsive release (about 50% release amount at pH 5.6 while

InP quantum dots (QDs) are considered as one of the most promising candidates of Cd- or Pb-based QDs in the applications of display and lighting. However, the performances of blue InP QDs and the corresponding light emitting devices (LEDs) are far inferior to those of their red and green counterparts, which strongly limits the development of InP QD based LEDs (QLEDs) technology. Here, high quantum yield (∼81%) and large size (∼7.0 ± 0.9 nm) InP/GaP/ZnS//ZnS QDs with a thick shell have been successfully synthesized by a shell engineering approach, and the corresponding QLEDs exhibit a record brightness and external quantum efficiency of 3120 cd·m-2 and 1.01%, respectively. Large-scale density functional theory calculations on thousands-of-atoms QDs indicate that thicker-shell ones favor a more balanced carrier injection in the QD film and simultaneously suppress the FRET between closely packed QDs, which collectively contribute to the improved blue device performances.

This article reports new tris‐cyclometalated Ir complexes containing mixed‐C^N ligands, (C^N1)2Ir(C^N2), which are a rarely explored class of Ir(III) complexes. Two new mixed 2‐phenylpyridine (ppy) / 4‐methyl‐2,5‐diphenylpyridine (mdp) complexes (ppy)2Ir(mdp) and (ppy)Ir(mdp)2 have been synthesized and their optoelectronic properties have been systematically characterized. Photoluminescence quantum yield values are 0.76‐0.85; excited state lifetimes are 0.07‐0.11 μs. Phosphorescent organic light emitting devices (PhOLEDs) based on these emissive complexes in a very simple device architecture reproducibly showed slightly higher external quantum efficiency (EQE) and power efficiency (PE) values compared with devices using the analogous conventional homoleptic Ir complexes Ir(ppy)3 and Ir(mdp)3, and the heteroleptic complexes (ppy)2Ir(acac) and (mdp)2Ir(acac). The new complexes (ppy)2Ir(mdp) 3 and (ppy)Ir(mdp)2 4 give PhOLEDs with EQEmax and PEmax values of 26.7 and 26.0% / 94.7 and 94.1 lm W−1, respectively, and very high values are retained at the practical luminances of 100 and 1000 cd m−2. The values for (ppy)2Ir(mdp) are 26.3% and 73.6 lm W−1 (at 100 cd m−2) and 24.6% and 53.5 lm W−1 (at 1000 cd m−2). These efficiencies are comparable with the highest reported values of PhOLEDs using conventional Ir(III) emitters in more complicated device structures. Mixed C^N ligand systems are, therefore, a viable strategy for developing new efficient phosphorescent emitters.

Nitrogen oxide (NOx) emissions have attracted much attention for increasing concern on the quality of the atmospheric environment. In view of NO decomposition in the cement production process, the preparation of Cu-Al/SiO2 porous material and its effect on NO decomposition were studied, and the denitrification mechanism was proposed in this paper. The NO decomposition performance of the Cu-Al/SiO2 porous material was tested via the experimental setup and infrared spectrometer and micro gas chromatography (GC). The result shows that the Cu-Al/SiO2 porous material with the template of cetyltrimethylammonium bromide (CTAB) had a better NO decomposition rate than materials with other templates when the temperature was above 500 &deg, C, and NO decomposition rate could approach 100% at high temperatures above 750 &deg, C. Structure analysis indicates that the prepared Cu-Al/SiO2 material structure was a mesoporous structure. The X-Ray Diffraction (XRD) and Ultraviolet&ndash, visible spectrophotometry (UV&ndash, Vis) results of the denitrification product show that the Cu-Al/SiO2 material mainly decomposed to Cu2O and Si2O, and the CuO decomposed to Cu2O and O2 at high temperature. The Cu(I)O was considered as the active phase. The redox process between Cu(II)O and Cu(I)O was thought to be the denitrification mechanism of the Cu-Al/SiO2 porous material.

Colloidal quantum dots (QDs) of group III-V are considered as promising candidates for next-generation environmentally friendly light emitting devices, yet there appears to be only limited understanding of the underlying electronic and excitonic properties. Using large-scale density functional theory with the hybrid B3LYP functional solving the single-particle states and time-dependent density functional theory accounting for the many-body excitonic effects, we have identified the structural, electronic, and excitonic optical properties of InP, GaP, and GaInP QDs containing up to a thousand atoms or more. The calculated optical gap of InP QD appears in excellent agreement with available experiments, and it scales nearly linearly with the inverse diameter. The radiative exciton decay lifetime is found to increase surprisingly linearly with increasing the dot size. For GaP QDs we predict an unusual electronic state crossover at a diameter of around 1.5 nm, whereby the nature of the lowest unoccupied molecular orbital (LUMO) state switches its symmetry from ${\mathrm{\ensuremath{\Gamma}}}_{5}$-like at a larger diameter to ${\mathrm{\ensuremath{\Gamma}}}_{1}$-like at a smaller diameter. After the crossover, the absorption intensity of the band-edge exciton states is significantly enhanced. Finally, we find that Vegard's law holds very well for GaInP random alloyed quantum dots down to ultrasmall sizes with less than a hundred atoms. The obtained energy gap bowing parameter of this common-cation compound in QD regime appears positive, size-dependent, and much smaller than its bulk parentage. The volume deformation, dominating over the charge exchange and structure relaxation effects, is mainly responsible for the QD energy gap bowing. The impact of excitonic effects on the optical bowing is found to be marginal. The present work provides a road map for a variety of electronic and optical properties of colloidal QDs in group III-V that can guide spectroscopic studies.

The biocompatibility and anticancer effect of hydroxyapatite nanoparticles (HAPNs) are compelling and promising in cancer nanomedicine. However, the essential role of fetal bovine serum (FBS) in a biological environment possibly determining the state of agglomeration and intracellular fate of HAPNs (length: ~ 60 nm; width: ~ 20 nm) has never been studied. Here, we investigated the importance of FBS in agglomeration and cell response of HAPNs in human osteosarcoma MG-63 cells. Protein adsorption on the surface of HAPNs after mixing with different concentrations of FBS was confirmed using transmission electron microscope (TEM), attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy, quartz crystal microbalance with dissipation (QCM-D), and thermogravimetric analysis (TG). The adsorption of serum protein improved dispersed state and stabilization of HAPNs, which was evidenced by dynamic light scattering (DLS), inverted microscope, and scanning electron microscope (SEM). More specifically, the agglomerate size of HAPNs in cell culture medium without FBS was above 1400 nm, while the agglomerate size of HAPNs with 10% FBS was decreased to about 200 nm and maintained for at least five days. Meanwhile, serum protein adsorption on HAPN surface enhanced cellular uptake and anticancer efficacy of HAPNs in MG-63 cells.

Five blue-emitting cationic Ir(III) materials with the form [ I r ( C ∧ N ) 2 ( N ∧ N ) ] + , where C ∧ N = 2-(2,4-difluorophenyl)pyridine (dfppy) cyclometalating ligands, and N ∧ N = biimidazole-type ancillary ligands, are investigated through a comprehensive theoretical scheme. Experimental researches concentrating on decorations of ancillary ligand, revealed that complex with 1,1′-CH3-2,2′-biimidazole (dMebiim) ancillary ligand is a non-emissive material due to the detrimental twisting of dMebiim resulting from steric hindrance of the methyl groups. When getting rid of methyl substituents that becomes the complex with a 1,1′-H-2,2′-biimidazole ancillary ligand, the quantum efficiency has been lifted to a large extent. Further rigidifying the biimidazole-type ancillary ligands, complex with an ortho-xylyl-tethered biimidzole ancillary ligand (1) was synthesized and has a higher quantum yield. From experimental aspect, the approaches employed in quantum efficiency enhancement is mainly concentrate on geometrical control through chelate effect. However, from theoretical aspect, we are not confined the strategies to rigidify the biimidazole ligand by divers chelates. In this study, our comprehensive theoretical scheme is firstly employed on the synthesized complex 1. Results show that the calculated radiative ( k r )and non-radiative ( k n r ) decay rates are consistence with the experimental findings. And further vibrational analysis clarified its nuclear behaviors during electronic transitions. Based on such vibrational analysis, it is found that substituting on the flanks of biimidzole can also effectively avoid detrimental twist. Therefore, in this study, we provide several new designed Ir(III) materials with substituent groups on the flanks of biimidzole, with the consideration of electron-withdrawing or -donating characters of the substituent groups. And Ir(III) materials with better performance are predicted from theoretical aspect.

We propose an explicit surface-potential-based direct current (dc) model for fully depleted polysilicon (poly-Si) thin-film transistors (TFTs). Being analytical and explicit, the proposed model is a solid base for compact models of these devices. The essential for our model is the explicit calculation of the surface potential, using the Lambert W function. Subsequently, using the surface potential, we also develop the expressions for charge and current, employing well established approaches, which include integration of carrier’s charge for drain current. Furthermore, the solutions of surface potential and drain current were validated by numerical results and experimental data, respectively. Finally, we discussed in detail about the effects on the surface potential and dc properties from the full depleted poly-Si TFT parameters. As a result, such a model is suitable to be implemented into computer-aided simulations of both device and circuit designs, due to its high computational accuracy and efficiency.

High concentration p-type AlInP material is an important layer to achieve low resistant and large carrier confinement in short-wavelength red-light laser diodes (LDs). To investigate the Mg doping behavior and other characteristics in the red-light LDs with tensile GaInP well structure, two LDs wafers with different Mg-doped AlInP cladding layers were grown by the metalorganic chemical vapor deposition (MOCVD) method. Incorporation and activation behavior of Mg atoms in heavily-doped AlInP were analyzed by the comparisons between hole concentration and atom concentration. We demonstrate that it is possible to achieve hole concentration above 1018 cm−3 using Mg dopant in AlInP layers just by an in-situ annealing. Furthermore, a hole concentration as high as 2.92 × 1018 cm−3 was achieved after post rapid thermal annealing in the N2 atmosphere, which is the highest hole doping concentrations reported to-date for the p-AlInP material.

A series of functional CeBiO x nanofibers (NFs) with different Ce:Bi molar ratios were successfully prepared by a facile two-step synthetic procedure including electrospinning and calcination. After systematic characterization of their morphology and structure/composition using various advanced techniques, the as-synthesized CeBiO x NFs were employed to modify screen-printed electrodes (SPEs) for the determination of fever reliever/pain reducer drug acetaminophen (AP) via both cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The results showed that the electrocatalytic activity of CeBiO x NFs was heavily dependent on Ce:Bi molar ratio and the Ce 0.75 Bi 0.25 O x NFs resulted in the highest electro-oxidation signal for AP among all Ce:Bi molar ratios tested in this study. Moreover, the Ce 0.75 Bi 0.25 O x NFs modified SPE showed a sensitivity of 360 μA mM −1 cm −2 , a low detection limit of 0.2 μM (signal to noise ratio of 3), a wide linear range up to 130 μM for DPV-based AP detection, and good intra- and inter-electrode reproducibility. Both the selectivity against uric acid, glucose, dopamine, ascorbic acid and the accuracy of the developed sensor for real sample analysis were also investigated using commercial paracetamol tablets and AP-spiked human serum samples.

The reaction mechanism of selective catalytic reduction of NO with ammonia (SCR) on MnOx/TiO2 catalysts was investigated through experiments and density functional theory (DFT) calculation. Firstly, the catalytic performance of catalyst with different molar ratios of MnOx/TiO2 was investigated and then was analyzed by NH3 temperature programmed desorption (NH3-TPD). The crystalline structure and the valence state of the MnOx/TiO2 catalyst were characterized by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). According to the results, the model of MnOx/TiO2 was established. Secondly, the different active sites of catalyst surface and adsorption characteristics of reacting gases during the SCR reaction based on in-situ DRIFT was investigated. Finally, the energy of different elemental reaction and isomerization of intermediate was calculated by MS Dmol3. It was found that the main active substance of catalyst was Mn4+ species which distributed dispersedly on the catalyst surface. The introduction of MnOx dopant can promote the adsorption of gas and reduce the formation energy of oxygen vacancy. The complete catalytic cycle goes in three steps: (a) Lewis acid site reaction follows Eley-Rideal mechanism; (b) Bronsted acid site reaction follows Langmuir-Hinshelwood mechanism; (c) Regeneration of catalyst.

Bi2X3 (X = S, Se, and Te) binary compounds have been widely studied as thermoelectric materials and reference topological insulators. Replacing one of the X atoms with a different atom Y of the same group has resulted in a new family of ternary compounds Bi2X2Y (X, Y = O, S, Se, and Te), which have attracted increasing attention very recently. By means of first-principles calculations within density functional theory, we have systematically studied the geometric structures and electronic properties of the whole family of these ternary compounds. We find that these compounds can be divided into two major groups. The first is traditional semiconductors, which include (i) Bi2O2Y, (ii) Bi2S2Y, and (iii) Bi2OY2. The other is topological insulators, which are (i) Bi2Se2Y and (ii) Bi2Te2Y. The optimized lattice parameters, band gaps as well as effective masses are in excellent agreement with recently available experimental measurements. In particular, we have found a new semiconductor material Bi2S2Te, which possesses an orthorhombic structure in space group pnma with a moderate direct gap of 0.5 eV at the HSE06 level and a small hole effective mass (∼0.22m0), which should favour fast hole transport and deserves further experimental studies. This work provides a road map for the exploration of the fundamental properties of the ternary compounds in this family as well as for their practical applications at the device level.

Massive blood loss and bacterial infection are major challenges for global public health. In this study, we developed tannic acid (TA)-loaded mesoporous silica (MS) nanoparticles for both hemorrhage control and effective antibacterium via covalent conjugation and electrostatic adsorption. The TA-absorbed MS could significantly relieve hemolysis and facilitate blood contact, therefore efficiently promoting protein adhesion and the contact activation pathway of the coagulation cascade with desirable hemostasis. Comparably, with increasing TAs absorption, the bleeding control and antibacterial performance were improved simultaneously, especially for 15TMS. Hemostasis tests demonstrated that the 15TMS could reduce the hemostatic time by 65% both in vitro and in vivo, with lower blood loss and could exhibit better antibacterial activities against Staphylococcus aureus and Staphylococcus epidermidis as well as promote wound healing. However, the TAs-loaded MS via chemical grafting (15T-g-MS) significantly reduced the surface area of MS, by replacing the Si-OH on the MS, and thus it exhibited worse bleeding control and antibacterial efficacy than 15TMS. Furthermore, all the samples exhibited excellent cell viability. Based on these results, it can be concluded that the 15TMS would be a promising material platform for designing hemostats in more extensive clinical application.

Autofluorescent bovine serum albumin (BSA) hydrogel microspheres were prepared through the spray-drying of glutaraldehyde cross-linked BSA nanoparticles and then used for a proteinase K based degradation study in an aqueous solution. Experimental results and empirical models are presented to characterize the kinetics of BSA hydrogel microsphere degradation, as well as the accompanying release of synthesized fluorophore. The BSA gel degradation dynamics is primarily controlled by the concentration of proteinase K within the Tris buffer. The coupling of swelling dynamics and the transient distributions of fluorophore are traced by confocal microscopy. Models are developed based on the linear theory of elastic deformation coupled to enzyme and fluorophore transport. This study represents a fundamental investigation of the degradation and release kinetics of protein-based materials, which can potentially be applied for the dynamic and photostable tracking of relevant in vivo systems.

Determining the amine molecules behaviors in the nanochannels enables the interpretation of the microstructure and macroscopic properties of amines modified cement based materials. In this study, quantitative analysis were performed on the behaviors of amine molecules (TEPAs, PAMs and TEAs) by molecular dynamics (MD) simulation in the nanochannels of C–S–H gel. According to the interaction of amine molecules with C–S–H gel substrates or water molecules, research works revealed that amine molecules with special spatial structures illustrate different aggregation behaviors. TEPAs with linear structures tend to aggregate in a regular sequence at the center of the C–S–H gel nanochannels. Instead, PAMs and TEAs with branched structures prefer dispersing in the aqueous solution in the C–S–H gel nanochannels. Such different aggregation behaviors allow amine molecules to have various penetration depth and residence time in the interfacial regions. It was found that oxygen atoms and active hydrogen atoms in PAMs and TEAs can form stable interaction with calcium ions and oxygen atoms of C–S–H gel substrates, respectively. The oxygen involved bonds are stronger than nitrogen involved ones for all the molecules due to great electronegativity. There is no formation of hydrogen bonds in TEPAs, but polar atoms in PAMs and TEAs can interact through hydrogen bonding. Moreover, TEPAs cannot form strong hydrogen bonding with water molecules due to their aggregation behavior, whereas PAMs and TEAs formed strong hydrogen bonding with surrounding water molecules. In addition, formation of more hydrogen bonding with amine molecules leads to a lower diffusion coefficient of water molecules. Breakage of hydrogen bonds of water molecules causes the final failure of C–S–H/amine molecules nanocomposites subjected to tensile loads.

Photocatalytic reduction of Cr(Ⅵ) is a safe, economical and clean method. In this study, a series of photocatalysts based on N-I co-doped TiO2 supported on activated carbon (denoted as x/yNIT@AC-z, N-I/Ti = x/y, calcination temperature = z °C) were synthesized, characterized and utilized for Cr(Ⅵ) photocatalytic reduction. Results of characterization revealed that all the prepared TiO2 existed in the form of monocrystalline tetragonal anatase phase with the particle size of 20 nm. Among them, 1/2NIT@AC-350 exhibited the highest photocatalytic performance. 1/2NIT@AC-350 showed a narrow band gap of 2.77 eV, which was chiefly because of the role of defect levels caused by pentavalent iodine, interstitial and substitutional nitrogen. 1/2NIT@AC-350/UV light/citric acid system exhibited the complete removal of 50 mg/L Cr(Ⅵ), over four successive reuse cycles without any obvious decrease in its photocatalytic reduction capability. In addition, the activated carbon in 1/2NIT@AC-350 provided a high concentration reaction environment for TiO2 via electrostatic attraction, which makes the photocatalyst possess a strong photocatalytic reaction driving force even at low concentration. Cr(Ⅵ) was also successfully removed in an actual water matrix (Yangtze river). This study provides a promising demonstration for the treatment of environmental pollutants, especially for Cr(Ⅵ) in wastewater effluents.

Adopting a facile two-step hydrothermal method to fabricate an efficient hierarchical transition metal selenide MoSe2/CoSe2 nano-flakes (NFs) anchored on carbon fiber paper (CFP) as a high-efficiency electrocatalyst for hydrogen evolution reaction (HER). The morphology shows that the surface of CFP is uniformly covered by the abundant nanosheets. Benefitting from the hydrophilic, the nano-catalysts on the MoSe2/CoSe2@CFP can fully contact with water molecules and accelerate the electron transfer, therefore promoting the water splitting. The electrochemical measurement suggests that on condition that current density of 10 ​mA ​cm−2, this nanometer electrocatalytic material has only an overpotential of 137 ​mV (vs. the RHE), which is lower as compared to CoSe2 (398 ​mV), MoSe2 (461 ​mV) and CFP (595 ​mV). The Tafel slope of the nanocomposite is 55.9 ​mV dec−1, which is lower than CoSe2 (138.1 ​mV dec−1) and MoSe2 (175.9 ​mV dec−1). Furthermore, the self-supporting nanocomposite exhibits outstanding stability in alkaline solution.

A Zoysia sinica Hance-based activated carbon (ZBAC) was synthesized via two-step method combining NH4Cl-assisted hydrothermal pretreatment and NaOH activation for the removal of Rhodamine B (RhB) in aqueous. The physical and chemical properties of the as-prepared activated carbon were investigated through the usage of X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and Brunauer-Emmett-Teller (BET) analysis. A series of batch experiments have been used to visually evaluate the various parameters (pH, dosage, reaction time and actual water condition) affecting the adsorption experiments. Results revealed that the aimed activated carbon exhibited superior adsorption capacities for RhB (1375.8 mg/g) due to its specific surface area (1307 m2/g) and available porosity. In addition, the adsorption of RhB could well-fitted by the Langmuir isotherms model and pseudo-second-order kinetic model, corresponding to monolayer and chemical adsorption respectively. As for the study of adsorption mechanism, ion exchange interactions and hydrogen bonding may be dominant for adsorbing RhB molecules by the activated carbon. The findings of the present work could provide a promising strategy to develop high-performance adsorbents for dye removal from wastewater using biochar derived from waste grass cuttings.

The self-supporting electrocatalysts have been demonstrated more advantages than powder catalysts. Both metal-support interaction and support effect further exhibit that the substrate material has significant impact on the electrochemical performance of the catalysts. Herein, we introduce a nickel nanowires film (Ni-NNF), synthesized via hydrazine reduction under a magnetic field, as a conductive substrate. By comparing with common substrates (Ni foam, carbon cloth and carbon fiber paper), the as-fabricated Ni-NNF exhibits higher conductivity and provides more active sites, resulting in better hydrogen evolution reaction (HER) activities and excellent durability. Thus, employing this type of metal nanowires as substrate is expected to synthesize better electrocatalyst.

With the development of smart materials, stimulus-responsive self-repairing materials attract more and more research attention. Although self-healing materials including concretes, rubbers, and hydrogels have been extensively investigated in the past decades, novel functionalities or properties such as shape memory, sol–gel transition, adhesion, anti-biofouling, and electronic/magnetic property have been introduced to self-repairing systems in recent years in order to broaden the scope of their applications in energy, drug delivery, tissue adhesion, cell culture, etc. In this paper, we first present an overview of the general strategies to prepare self-healing materials and the characterization methods to assess their healing performance. Then, we mainly focus on reviewing recent progress in novel self-healing materials possessing unique functionalities and their potential applications in biomedical engineering. Finally, the challenges and scope for future development are also discussed.

A physics-based drain current compact model for amorphous InGaZnO (a-InGaZnO) thin-film transistors (TFTs) is proposed. As a key feature, the surface potential model accounts for both exponential tail and deep trap densities of states, which are essential to describe a-InGaZnO TFT electrical characteristics. The surface potential is solved explicitly without the process of amendment and suitable for circuit simulations. Furthermore, based on the surface potential, an explicit closed-form expression of the drain current is developed. For the cases of the different operational voltages, surface potential and drain current are verified by numerical results and experimental data, respectively. As a result, our model can predict DC characteristics of a-InGaZnO TFTs.

A physics-based compact model for double-gate polysilicon thin-film transistors (TFTs) with a doped channel is proposed in this paper. Through the effective charge density approach, the electrostatic potential is solved explicitly from the Poisson’s equation without using the conventional regional approach. The resulting single-piece electrostatic potential equation, which does not consist of the intermediate parameter, offers clear physics meaning and good accuracy, particular when the TFT operates in the transition region. The TFT’s drain current model is then developed by integrating the electrostatic potential equation analytically with the Pao-Sah equation. Finally, the model is verified by numerical and experimental data. Such a compact model is highly suitable for circuit simulations.

Localized, continuous and effective osteogenic stimulation to defected sites is still a great challenge for recombinant human bone morphogenetic protein-2 (rhBMP-2) in clinical bone regeneration. In this study, a novel delivery system was engineered to tether rhBMP-2 onto the surface of calcium phosphate cement (CPC) based on the high affinity between alendronate and CPC, as well as the strong binding of heparin and rhBMP-2. Alendronate was first grated to heparin via the EDC/NHS reaction and then the resultant alendronate–heparin (AH) was adsorbed onto the CPC surface. RhBMP-2 was further anchored onto the CPC–AH surface. The results from in vitro release and in vivo fluorescence-labeled traces all indicated that the AH-tethered rhBMP-2 exhibited a more stable and stronger adherence to the CPC surface than the CPC-adsorbed and heparin-anchored ones. Moreover, based on the results of the alkaline phosphatase (ALP) activity in skeletal myoblasts (C2C12) in vitro and osteogenic efficacy in vivo, it could be seen that rhBMP-2-induced osteogenic bioactivity was also significantly enhanced on the CPC–AH surface. These results demonstrated that the tethering of rhBMP-2 onto calcium phosphate surface via AH presented an effective method to achieve a localized and sustained exposure to targeted cells, and consequently to promote bone regeneration.

Three novel phenothiazine-substituted oxime esters (Ph-PTZ-OXE, TPA-PTZ-OXE and CZ-PTZ-OXE) applicable to visible laser diodes (405 nm and 455 nm) were successfully designed and synthesised. The introduction of phenothiazine groups in oxime esters led to a significant redshift in UV-vis absorption, thereby making the oxime esters suitable for promoting photopolymerization under visible light irradiation. Upon exposure to the irradiation of a laser diode at 405 nm and 455 nm, the three oxime esters showed high polymerization efficiency in the free radical polymerization of tripropylene glycol diacrylate (TPGDA). The oxime ester system was paired with iodonium salt (ION) and exhibited high efficiency in promoting free radical polymerization. The photochemical mechanisms were established from the fluorescence spectrum, cyclic voltammograms (CV) and electron spin resonance (ESR) data. The iminyl radical is characterized by two quartets centered at 323.1 mT and 324.4 mT. The benzoyloxyl radical gives rise to two broad peaks at 320.9 mT and 336.7 mT, with a high g value characteristic of oxygen-centered radicals.

Three tensile GaInP quantum well laser diode wafers were grown in the same run by low-pressure metalorganic vapor phase epitaxy on GaAs substrates misoriented by 10°, 15°, and 22° toward (1 1 1)A respectively. The photoluminescence peak wavelength and intensity of the active region, the strain mismatch and the doping carrier concentration of the epitaxial layers, the whole thickness and the surface morphology of the wafers were all found to be strongly dependent on the misorientation of the substrates. Considering the comprehensive effects of material, electrical, and optical properties, the 15° substrate was superior to the 10° substrate for the growth of shorter wavelength red-light laser diode wafer, while substrate with too large misorientation of 22° was not a good choice for the epitaxy of red-light laser diode wafer.

Solid lipid nanoparticles (SLNs) are regarded as promising carriers to improve the safety and effectiveness of delivery for drugs and nutrients, however, the clinic applications for oral administration are limited by their poor stability in gastrointestinal conditions. In this study, surface modification was explored to confer new physicochemical properties to SLNs and thus achieve enhanced functionalities. Novel SLNs with biopolymeric double layer (DL) coating using two natural biopolymers, i.e. caseinate (NaCas) and pectin, were prepared to encapsulate and deliver curcumin, a lipophilic bioactive compound studied as a model drug/nutrient. The DL coating was chemically cross-linked by creating covalent bonds between NaCas and pectin, using two different cross-linkers, i.e. glutaraldehyde (GA) and 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-Hydroxysuccinimide (EDC/NHS). Prior to cross-linking, the mean particle size, polydispersity index and zeta potential of DL-SLNs were 300-330nm, 0.25-0.30, -45-40mV, respectively. It was found that cross-linking with GA had a more prominent effect on particle size and polydispersity index than EDC/NHS. The cross-linking process significantly improved physicochemical properties of DL-SLNs, resulting in higher encapsulation efficiency and loading capacity, better stability and slower release profile in simulated gastrointestinal conditions. Particularly, an optimal zero-order release kinetic was observed for EDC/NHS crosslinked DL-SLNs. The electron microscopy revealed that both cross-linked DL-SLNs exhibited spherical shape with homogeneous size and smooth surface. Encapsulation of curcumin in SLNs dramatically enhanced its antioxidant activity in aqueous condition. The cross-linking process further helped spray drying of SLNs by forming homogenous powder particles. These results indicated that coating with cross-linked polymers could significantly improve the physicochemical properties of SLNs and expand their potentials as oral delivery systems for lipophilic nutrients and drugs.

The gate-leakage behavior in GaN-based high electron mobility transistors (HEMTs) is studied as a function of applied bias and temperature. A model to calculate this current is given, which shows that trap-assisted tunneling, trap-assisted Frenkel-Poole (FP) emission, and direct Fowler-Nordheim (FN) tunneling have their main contributions at different electric field regions. In addition, the proposed model clearly illustrates the effect of traps and their assistance to the gate leakage. We have demonstrated the validity of the model by comparisons between model simulation results and measured experimental data of HEMTs, and a good agreement is obtained.