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This article presents the design of a core–shell–shell nanostructured spherical aluminum powder (Al@PDA@POSS) through in-situ polymerization. The transient plane source method and infrared thermal imaging results demonstrate that the double-shell nanostructure can significantly enhance the compatibility of aluminum powder in an epoxy resin. Al@PDA@POSS was self-assembled with magnetic iron oxide to form a hybrid filler (Al@PDA@POSS-Fe3O4), resulting in magnetic properties. The hybrid fillers were precisely oriented in the resin matrix driven by magnetic force, constructing an effective thermal conduction path. Magnetic orientation plays a key role during the construction of a “thermal bridge”. The directionally arranged filler composite (OA-Al@PDA@POSS-Fe3O4/EP) exhibits a thermal conductivity of 1.249 W/(m K) and an electrical conductivity of 5.56 × 10–10S/cm at a load of 40 wt %. Compared to traditional composites, OA-Al@PDA@POSS-Fe3O4/EP composites not only possess high thermal conductivity and excellent insulation properties but also exhibit good thermal mechanical properties.

ABSTRACTWe demonstrate a method to evaluate the urban residential land use efficiency from the perspective of service facility capacity by using a neural network. Publicly available data were used to obtain the physical and socioeconomic information. Combining the actual carrying capacity calculated from the residential population and the theoretical carrying capacity calculated from the service facility density, we trained a back-propagation neural network to evaluate the efficiency of residential land use. The results show that the degree of residential land use can be reflected through the carrying capability of service facilities. Beijing’s residential land efficiency presents a spatial distribution form that declines from the centre to the edge. We also found a phenomenon that the efficiency of the residential land at the junction of administrative districts is relatively low. Our research demonstrates how multi-source publicly available data and neural network algorithms can be applied to solve complicated social issues.

Atmospheric substances can enter surface water through dry and wet deposition, which contributes to surface water pollution and is one indispensable cause of water eutrophication. Rainwater is a high-quality alternative drinking water source in water shortage areas. Rainwater disinfection is necessary to ensure its microbiological safety, but disinfection usually produces disinfection by-products (DBPs) and brings chemical risk to water. Dissolved organic matter (DOM) derived from the atmosphere may contribute to the formation of DBPs during water disinfection. In this study, the effects of wet and dry deposition on surface water quality and rainwater DBP formation as well as the control technologies of rainwater DBPs were comprehensively reviewed. Dry and wet deposition contributed compounds (sulphates, ammonium, alkali and ions), trace elements (Fe, Mn, Al, Cu, Zn, La, U, Th, Cd, As and Hg) and microplastics to surface water. The contribution of dry deposition to water pollution was enhanced in gale weather in areas with severe air pollution. The formation potential of CX3R-type DBPs (THMs, HAAs, HALs, HANs, HNMs and HAMs) was increased, because dry and wet deposition contributed DBP precursors. Low molecular weight DOM was more likely to generate DBPs, so it is suggested to develop effective technology targeting low molecular weight DOM removal from rainwater. Among conventional drinking water treatment processes, the combination of GAC and chloramination is very promising for controlling the comprehensive toxicity risk of DBPs in rainwater. Future studies should focus on the correlation between DBP formation in rainwater and atmospheric pollution, especially in severely polluted areas, and the key factors affecting rainwater quality and DBP formation.

Flaky aluminum pigments with excellent corrosion resistance have found applications in diverse fields. In this study, a fluoropolymer has been incorporated in the aluminum pigment to effectively enhance its corrosion resistance, along with the improvement in the chemical resistance and thermal stability. Specifically, a uniform dense layer of poly(trifluoroethyl methacrylate) (PTFEMA) has been directly coated on the surface of the flaky aluminum pigment by in situ polymerization. The encapsulated aluminum pigment exhibited high stability upon dipping in the alkaline solution (pH = 13) due to protection imparted by the fluoropolymer layer. The morphology of the fluoropolymer layer on the surface of the aluminum pigment was characterized by scanning electron microscopy (SEM). Moreover, the thermal stability of the encapsulated aluminum pigment was analyzed by thermogravimetric analysis (TG). The structure and composition of the fluoropolymer layer were further characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The stability of the aluminum pigment in alkaline aqueous media was investigated via hydrogen evolution experiments. Overall, the corrosion resistance of the aluminum pigment encapsulated with fluoropolymer was observed to be markedly improved owing to the presence of the PTFEMA layer.

Induced pluripotent stem cells (iPSCs) have become an essential research platform to study different human diseases once being discovered by Dr. Shinya Yamanaka in 2006. Another breakthrough in biomedical research is the application of CRISPR/Cas9 system for genome editing in mammalian cells. Although numerous studies have been done to develop methods for gene editing in iPSCs, the current approaches suffer from several limitations, including time and labor consuming, low editing efficiency, and potential off-target effects. In the current study, we report an electroporation-mediated plasmid CRISPR/Cas9 delivery approach for genome editing in iPSCs. With this approach, an edited iPSC cell line could be obtained within 2 weeks. In addition, the transit introducing of CRISPR/Cas9 machinery could minimize genomic integration of Cas9 gene, which avoided potential long-term side effects of Cas9 enzyme. We showed that CRISPR/Cas9-mediated genomic editing did not affect pluripotency and differentiation ability of iPSCs. With the quickly evolving of both iPSC and CRISPR/Cas9-mediated genome editing research fields, we believe that our method can significantly facilitate the application of genome editing in iPSCs research.

Corneal wounds usually heal quickly; but diabetic patients have more fragile corneas and experience delayed and painful healing. In the present study, we compared the healing capacity of corneal epithelial cells (CECs) between normal and diabetic conditions and the potential mechanisms. Primary murine CEC derived from wild-type and diabetic (db/db) mice, as well as primary human CEC were prepared. Human CEC were exposed to high glucose (30 mM) to mimic diabetic conditions. Cell migration and proliferation were assessed using Scratch test and MTT assays, respectively. Reactive oxygen species (ROS) production in the cells was measured using dichlorofluorescein reagent. Western blot was used to evaluate the expression levels of Akt. Transepithelial electrical resistance (TEER) and zonula occludens-1 (ZO-1) expression were used to determine tight junction integrity. We found that the diabetic CEC displayed significantly slower cell proliferation and migration compared with the normal CEC from both mice and humans. Furthermore, ROS production was markedly increased in CEC grown under diabetic conditions. Treatment with an antioxidant N-acetyl cysteine (NAC, 100 μM) significantly decreased ROS production and increased wound healing in diabetic CEC. Barrier function was significantly reduced in both diabetic mouse and human CEC, while NAC treatment mitigated these effects. We further showed that Akt signaling was impaired in diabetic CEC, which was partially improved by NAC treatment. These results show that diabetic conditions lead to delayed wound-healing capacity of CEC and impaired tight junction formation in both mice and human. Increased ROS production and inhibited Akt signaling may contribute to this outcome, implicating these as potential targets for treating corneal wounds in diabetic patients.

A new kind of all-inclusive organic-inorganic nanospheres were prepared by mild biomimetic process. They were employed as ideal signal nano-labels for enhanced electrochemical immunosensor of nuclear matrix protein 22. Owing to the signal amplified mechanism, the improved electrochemical immunosensor will provide reliable and excellent detection performance, which has potential application for detecting biomarkers.

In attempts to investigate the potential luminescent sensing materials for sensitive detection of environmental pollutants, a new family of lanthanide wheel cluster organic frameworks (Ln-WCOFs) UJN-Ln4has been constructed by employing one of the cycloalkane dicarboxylic acid derivatives. Adopting different conformations, the ligand links Ln4second building units (SBUs) and Ln24tertiary building units (TBUs) to form a unique wheel cluster layer-pillared 3D framework featuring the coexistence of hydrophobic nanosized channels and trigonal antiprism arrays with hydrophilic cagelike chambers. Apart from charming structures, isostructural UJN-Ln4displays interesting porous, water-stable features. Systematic luminescence studies demonstrate that solvent water molecules can enhance the emission intensity of solid-state UJN-Eu4. Acting as a recyclable luminescent probe, water-stable luminescent UJN-Eu4exhibits superior “turn-off” detection for Fe3+and Cu2+ions in aqueous solutions. Due to the nanosized hydrophobic channels, UJN-Eu4also shows highly sensitive sensing of sodium dodecyl benzenesulfonate (SDBS) via luminescence “turn-on” respondence, representing the first example of quantitatively detecting SDBS in aqueous solutions by employing luminescent lanthanide frameworks as fluorescent sensors. The results also open up the exploration of novel luminescent Ln-WCOFs exhibiting unique applications in sensitive detecting of harmful pollutants in aquatic environments.

A series of copolymers of 2,2,2-trifluoroethyl methacrylate (FMA) and methyl acrylate (MA) with different copolymer compositions were synthesized by solution polymerization. The chemical structure of copolymers was characterized by fourier transform infrared spectroscopy (FTIR), 1H NMR, and 19F NMR. The reactivity ratios for FMA (r1) and MA (r2) were found to be 1.83 and 0.31 by the Fineman–Ross method and 1.91 and 0.34 by the Kelen–Tudos method, respectively. The glass transition temperature of the copolymers decreased with increasing MA content and ranged from 77.5 to 13.4°C for a feed composition of 90 mol% MA monomer, while, according to water contact angle data, the hydrophilic properties of the copolymer coatings increased with increasing MA feed composition. Remarkably, when the feed composition of MA was 60 mol%, the glass transition temperature was reduced to 29.2°C, while the obtained copolymer exhibited comparable hydrophobic property to the PFMA homopolymer.

In this study, a novel strategy is utilized to prepare colored aluminum pigments with smart and optimal alkali resistance by in situ growth of multilayer composite nanomaterials on aluminum powders. A layer of a metal–organic framework (MOF) is constructed on the aluminum pigments by an in situ electrostatic self-assembly process. Copper-based metal–organic frameworks (CuMOFs) with excellent adsorption properties are utilized as nanocontainers for loading corrosion inhibitors (benzotriazole). The aluminum powder with the CuMOF functional layer (Al@CuMOF) has smart anticorrosion performance and vibrant colors. The MOF functional layer evenly releases benzotriazole to protect the aluminum powders from corrosive environments. Furthermore, the poly(trifluoroethyl methacrylate) layer with uniformity and denseness is tightly coated on the MOF functional layer to increase weatherability. The electrochemical impedance spectroscopy demonstrated that the highest impedance of the multifunction aluminum powders was as high as 7.23 × 105Ω cm2, indicating excellent and durable chemical stability.

Grafting of maleic anhydride (MA) onto styrene–butadiene–styrene triblock copolymer (SBS) was carried out by free radical polymerization using supercritical carbon dioxide (SC CO2) as a solvent of MA and swelling agent of SBS. The effect of various factors such as monomer concentration, initiator concentration, SC CO2 pressure, and reaction time on grafting ratio was studied. SBS and the product (SBS‐g‐MA) were characterized by Fourier transform infrared spectroscopy (FTIR), gel permeation chromatography (GPC), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). GPC data showed that the molecular weight of SBS‐g‐MA is bigger than that of SBS. DSC testing indicated that the glass transition temperature (Tg) of SBS‐g‐MA is higher than that of SBS. By SEM photo, we can observe that some particles which contain more oxygen atom grew out from the surface of SBS‐g‐MA when grafting ratio reached at 5.6%, and the amount and diameter of particles increased with increasing of grafting ratio. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4425–4429, 2006