In-situelectrochemical polymerization of aniline on flexible conductive substrates for supercapacitors and non-enzymatic ascorbic acid sensors.

Polyaniline, as a kind of conductive polymer with commercial application prospects, is still under researches in its synthesis and applications. In this work, polyaniline was fabricated on flexible substrates including carbon cloths and polyethylene naphthalate byin situelectropolymerization method. The synthesized flexible electrodes were characterized by scanning electron microscopy, High resolution transmission electron microscope, atomic force microscope, Fourier transform infrared, x-ray diffraction, and x-ray photoelectron spectroscopy. Owing to the conductivity and the reversible redox property, the polyaniline/carbon cloth electrodes show excellent properties such as decent supercapacitor performance and good detection capability toward ascorbic acid. As supercapacitors, the electrodes exhibit a specific capacitance as high as 776 F g-1at a current density of 1 A g-1and a long cycle life of 20 000 times in the three-electrode system. As ascorbic acid sensors, the flexible electrodes demonstrate stable response to ascorbic acid in the range of 1-3000µM with an outstanding sensitivity (4228µA mM-1cm-2), low detection limit (1µM), and a fast response time. This work holds promise for high-performance and low-cost flexible electrodes for both supercapacitors and non-enzymatic ascorbic acid sensors, and may inspire inventions of self-powered electrochemical sensor.

ROCK inhibitor attenuates carbon blacks-induced pulmonary fibrosis in mice via Rho/ROCK/NF-kappa B pathway.

Exposure to carbon blacks (CBs) has been associated with the progression of pulmonary fibrosis, whereas the mechanism is still not clear. We therefore aimed to investigate the effect of RhoA/ROCK pathway on pulmonary fibrosis caused by CBs exposure. Western blot analysis indicated that CBs could promote the activation of RhoA/ROCK pathway and phosphorylation of p65 and IκBα in mice lung. However, ROCK inhibitor Y-27632 could attenuate phosphorylation levels of p65 and IκBα and restore histopathological changes of the lung tissue. Then, we evaluated the effect of RhoA/ROCK pathway on pulmonary fibrosis by detecting the expression levels of α-SMA, vimentin, and Collagen type-I (Col-I), which could be partly inhibited by Y-27632. It was assumed that inhibition of ROCK could be a promising therapeutic candidate for CBs-induced pulmonary fibrosis, which possibly through the blockage of RhoA/ROCK/NF-κB pathway.

Twin-ZnSe nanowires as surface enhanced Raman scattering substrate with significant enhancement factor upon defect.

Semiconductor-based surface enhanced Raman scattering (SERS) substrate design has attracted much interest due to the excellent photoelectronic and biochemical properties. The structural change caused by twin in semiconductor will have an influence on improving the Raman signals enhancement based on the chemical mechanism (CM). Here, we demonstrated the twin in semiconductor ZnSe nanowires as an ultrasensitive CM-based SERS platform. The SERS signals of the rhodamine 6G (R6G) and crystal violet (CV) molecules adsorbed on twin-ZnSe nanowires could be easily detected even with an ultralow concentration of 10-11 M and 10-8 M, respectively, and the corresponding enhancement factor (EF) were up to 6.12 × 107 and 3.02 × 105, respectively. In addition, the charge transfer (CT) between the twin-ZnSe nanowires and R6G molecule has been demonstrated theoretically with first-principles calculations based on density-functional theory (DFT). These results demonstrated the proposed ZnSe nanowires with twin as SERS substrate has a broader application in the field of biochemical sensing.

Characteristics of corn starch/polyvinyl alcohol composite film with improved flexibility and UV shielding ability by novel approach combining chemical cross-linking and physical blending.

With the aim of effectively improving the performance of bio-friendly food packaging and circumventing the hazards associated with petroleum-based plastic food packaging, composite films of corn starch and polyvinyl alcohol were prepared using a new method that involved chemical cross-linking of glutaraldehyde and blending with cinnamon essential oil nanoemulsion (CNE). Glutaraldehyde and CNE enhance the film's network structure by chemical bonding and hydrogen bonding, respectively. This results in improved surface smoothness, mechanical properties, and UV shielding ability of the film. However, the films' surface hydrophilicity increased as a result of CNE, which is harmful for food preservation in high humidity. Overall, glutaraldehyde and CNE have a synergistic effect on some of the properties of the film which is mainly attributed to the films' structure improvement. The films have great potential for preparing flexible and UV-shielding films and offer new ideas for developing biodegradable films.

Coordinated Transcriptome and Metabolome Analyses of a Barley hvhggt Mutant Reveal a Critical Role of Tocotrienols in Endosperm Starch Accumulation.

Tocotrienols and tocopherols (vitamin E) are potent antioxidants that are synthesized in green plants. Unlike ubiquitous tocopherols, tocotrienols predominantly accumulate in the endosperm of monocot grains, catalyzed by homogentiate geranylgeranyl transferase (HGGT). Previously, we generated a tocotrienol-deficient hvhggt mutant with shrunken barley grains. However, the relationship between tocotrienols and grain development remains unclear. Here, we found that the hvhggt lines displayed hollow endosperms with defective transfer cells and reduced aleurone layers. The carbohydrate and starch contents of the hvhggt endosperm decreased by approximately 20 and 23%, respectively. Weighted gene coexpression network analyses identified a critical gene module containing HvHGGT, which was strongly associated with the hvhggt mutation and enriched with gene functions in starch and sucrose metabolism. Metabolome measurements revealed an elevated soluble sugar content in the hvhggt endosperm, which was significantly associated with the identified gene modules. The hvhggt endosperm had significantly higher NAD(H) and NADP(H) contents and lower levels of ADPGlc (regulated by redox balance) than the wild-type, consistent with the absence of tocotrienols. Interestingly, exogenous α-tocotrienol spraying on developing hvhggt spikes partially rescued starch accumulation and endosperm defects. Our study supports a potential novel function of tocotrienols in grain starch accumulation and endosperm development in monocot crops.

Dynamic Spectral Modulation Enabled by Conductive Polymer-Integrated Plasmonic Nanodisk-Hole Arrays.

The electrically driven optical performance modulation of the plasmonic nanostructure by conductive polymers provides a prospective technology for miniaturized and integrated active optoelectronic devices. These features of wafer-scale and flexible preparation, a wide spectrum adjustment range, and excellent electric cycling stability are critical to the practical applications of dynamic plasmonic components. Herein, we have demonstrated a large-scale and flexible active plasmonic nanostructure constructed by electrochemically synthesizing nanometric-thickness conductive polymer onto spatially mismatched Au nanodisk-hole (AuND-H) array on the poly(ethylene terephthalate) (PET) substrate, offering low-power electrically driven switching of reflective light in a wide wavelength range of 550-850 nm. The composite structure of the polymer/AuND-H array supports multiple plasmonic resonance modes with strong near-field enhancement and confinement, which provides an excellent dynamic spectral modulation platform. As a result, the PPy/AuND-H array achieves 18.4% reversible switching of spectral intensity at 780 nm and speedy response time, as well as maintains a stable dynamic modulation range at two-potential cycling between -0.6 and 0.1 V after 200 modulation cycles. Compared to the case of the PPy/AuND-H array, the PANI/AuND-H array obtains a more extensive intensity modulation of 25.1% at 750 nm, which is attributed to the significant differences in the extinction coefficient between the oxidized and reduced states of PANI, but its modulation range degrades apparently after 20 cycles driven at applied voltages between -0.1 and 0.8 V. Additionally, the cycling stability could be further improved by reducing the modulation voltage range. Our proposed electromodulated composite structure provides a promising technological proposal for dynamically plasmonic reconfigurable devices.

Effects of Supercritical CO2 on the Pore Structure Complexity of High-Rank Coal with Water Participation and the Implications for CO2 ECBM.

To reveal how mineral changes affect a coal pore structure in the presence of water, an autoclave was used to carry out the supercritical CO2 (ScCO2)-H2O-coal interaction process. To reveal the changes in pore complexity, mercury intrusion capillary pressure (MICP), low-pressure nitrogen adsorption, CO2 adsorption, and field emission scanning electron microscopy (FESEM) experiments were combined with fractal theory. The experimental data of MICP show that the MICP data are meaningful only for the pore fractal dimension with pore sizes >150 nm. Therefore, the pores were classified into the classes >150, 2-150, and <2 nm. The results show that the pore volume and specific surface area of the coal increased significantly after the reaction. ScCO2-H2O can cause the formation of many new pores and fractures in the coal. The presence of H2O may increase the potential for the injection of CO2 into the coal seam. The complete dissolution of calcite surfaces caused a significant increase in the pore volume and specific surface area of the pores >150 nm. The morphologies of these pores are controlled by the morphologies of the complete dissolution carbonate particles. The pore morphologies were relatively uniform, and the fractal dimensions decreased. However, the incomplete dissolution of calcite leads to irregular variations in the morphologies for the pores in the 2-150 nm pore size range. The pore morphologies that are produced by incompletely dissolved calcite particles are more complex, which increases the fractal dimensions after the reaction. The fractal dimensions of the pores <2 nm decreased after the reaction, indicating that the newly generated micropores were more uniform and had regular pore morphologies.

Three-Dimensional Au/Ag Nanoparticle/Crossed Carbon Nanotube SERS Substrate for the Detection of Mixed Toxic Molecules.

Research on engineering "hotspots" in the field of surface-enhanced Raman scattering (SERS) is at the forefront of contributing to the best sensing indicators. Currently, there is still an urgent need to design a high-strength and large-scale electric field distribution method in order to obtain an ideal SERS sensor. Here, we designed a three-dimensional (3D) Au/Ag nanoparticle (NP)/crossed carbon nanotube film SERS substrate. The proposed structure formed by the simple preparation process can perfectly coordinate the interaction between the SERS substrates, lasers, and molecules. The denser "hotspots" can be induced and then distributed in holes enclosed by Au/AgNPs and the gaps between them. This process was verified by numerical simulations. The experimental results show that the proposed SERS substrate possesses an excellent sensitivity of 10-12 M (rhodamine 6G (R6G)), an enhancement factor of 1.60 × 109, and a good signal reproducibility (the relative standard deviation is ~6.03%). We further use a Au/AgNP/crossed CNT substrate to detect complex solutions composed of toxic molecules, which shows that our proposed SERS substrate has a wide range of application potentials, especially in food safety.

Influence of SERS Activity of SnSe2 Nanosheets Doped with Sulfur.

The application of 2D semiconductor nanomaterials in the field of SERS is limited due to its weak enhancement effect and the unclear enhancement mechanism. In this study, we changed the surface morphology and energy level structure of 2D SnSe2 nanosheets using different amounts of S dopant. This caused the vibration coupling of the substrate and the adsorbed molecules and affects the SERS activities of the SnSe2 nanosheets. SERS performance of the 2D semiconductor substrate can effectively be improved by suitable doping, which can effectively break the limitation of 2D semiconductor compounds in SERS detection and will have very important significance in the fields of chemical, biological, and materials sciences. In this work, the intensities of SERS signals for R6G molecules on SnSe0.93S0.94 are 1.3 to 1.7 times stronger than those on pure SnSe2 substrate. It not only provides a new way to effectively improve the SERS activity of a semiconductor SERS substrates but also helps to design more efficient and stable semiconductor SERS substrates for practical application.

Extremely Low Program Current Memory Based on Self-Assembled All-Inorganic Perovskite Single Crystals.

Memory devices based on lead halide perovskite have attracted great interests because of their unique current-voltage hysteresis. However, current memory devices based on polycrystalline perovskites usually suffer from large intrinsic electronic current and parasitic leakage current due to the existence of grain boundaries, which further leads to high power consumption. Here, a low-power resistance switching random-access memory device is demonstrated by assembling single-crystalline CsPbBr3 on Ag electrodes. The assembled structure serves as a bipolar nonvolatile resistance switching memory device with a low program current (∼10 nA), good endurance, long data retention (>103 S), and big on/off ratio of ∼103. The low program current results in a power of ∼3 × 10-8 W, which is much lower than that of polycrystalline perovskite-based devices (10-1-10-6 W). It is found that the formation and annihilation of Ag and bromide vacancy conductive filaments contribute to the significant resistive switching effect. At a low resistive state, the conductive filaments originate from the accumulation of Br- ions at the drain. Furthermore, the conductive filaments are proved to be a cone shape, shrinking from the drain to the source.

3D Ultrasensitive Polymers-Plasmonic Hybrid Flexible Platform for In-Situ Detection.

This paper introduces a three-dimensional (3D) pyramid to the polymers-plasmonic hybrid structure of polymethyl methacrylate (PMMA) composite silver nanoparticle (AgNPs) as a higher quality flexible surface-enhanced Raman scattering (SERS) substrate. Benefiting from the effective oscillation of light inside the pyramid valley could provide wide distributions of 3D "hot spots" in a large space. The inclined surface design of the pyramid structure could facilitate the aggregation of probe molecules, which achieves highly sensitive detection of rhodamine 6G (R6G) and crystal violet (CV). In addition, the AgNPs and PMMA composite structures provide uniform space distribution for analyte detection in a designated hot spot zone. The incident light can penetrate the external PMMA film to trigger the localized plasmon resonance of the encapsulated AgNPs, achieving enormous enhancement factor (~ 6.24 × 10 8 ). After undergoes mechanical deformation, the flexible SERS substrate still maintains high mechanical stability, which was proved by experiment and theory. For practical applications, the prepared flexible SERS substrate is adapted to the in-situ Raman detection of adenosine aqueous solution and the methylene-blue (MB) molecule detection of the skin of a fish, providing a direct and nondestructive active-platform for the detecting on the surfaces with any arbitrary morphology and aqueous solution.