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This study was to design a novel wide pH–sensing colorimetric film of κ-carrageenan incorporated with extract from Lycium ruthenicum Murr. (Car-LRM) for food freshness monitoring. The structure, basic properties (thermal stability, mechanical, barrier and antioxidant activity), and release kinetics of LRM from the films were investigated. Attentions were centered on colorimetric response of films and their applications for freshness monitoring of milk and shrimps. A low incorporation of LRM (no more than 2.5%) led to an enhancement in thermal stability and water vapor barrier of films to a certain extent. At above level of incorporation, LRM could be well-distributed in Car matrix by the interactions of hydrogen bonds. In addition to good antioxidant activity, the film displayed colorimetric response at a wide range of pH (2−10) and the color change was reversible. The release of LRM from films followed Fickian's law which was controlled by diffusion mechanism rather than swelling mechanism. The successful applications of Car-LRM2.5 for the freshness monitoring of milk and shrimps indicate that Car-LRM2.5 may have great potential for monitoring the freshness of milk and aquatic products.

Novel films based on κ-carrageenan (Car) incorporated with curcumin (Cur) were developed for freshness monitoring of foods. Cur and Car were interacted by hydrogen bonds. A low amount of Cur (no higher than 3%) could be well-dispersed in Car matrix. These characteristics significantly improved the film barrier and tensile strength, besides the enhancement of thermal stability. Hence, the Car film with 3% Cur exhibited the best performance. The films showed a good release control of Cur and a predominant Fickian diffusion release mechanism, which was favorable to sustainable pH change sensing. The Car-Cur films demonstrated a strong redness-shift under alkaline condition. This characteristic was successfully used to monitor the spoilage of pork and shrimp during storage. As a pH colorimetric indicator, the Cur incorporated Car films may have a great potential in the freshness monitoring of foods.

Insig-2 is an ER membrane protein negatively controlling lipid biosynthesis. Here, we find that Insig-2 is increased in the tissues, including liver, but unaltered in the muscle of gp78-deficient mice. In hepatocytes and undifferentiated C2C12 myoblasts, Insig-2 is ubiquitylated on Cys215 by gp78 and degraded. However, the C215 residue is oxidized by elevated reactive oxygen species (ROS) during C2C12 myoblasts differentiating into myotubes, preventing Insig-2 from ubiquitylation and degradation. The stabilized Insig-2 downregulates lipogenesis through inhibiting the SREBP pathway, helping to channel the carbon flux to ATP generation and protecting myotubes from lipid over-accumulation. Evolutionary analysis shows that the YECK (in which C represents Cys215 in human Insig-2) tetrapeptide sequence in Insig-2 is highly conserved in amniotes but not in aquatic amphibians and fishes, suggesting it may have been shaped by differential selection. Together, this study suggests that competitive oxidation-ubiquitylation on Cys215 of Insig-2 senses ROS and prevents muscle cells from lipid accumulation., The protein Insig-2 negatively regulates lipid biosynthesis and is short-lived in liver cells but stable in muscle cells. Here, the authors show that in muscle cells producing reactive oxygen species, there is increased oxidation compared to ubiquitination of Insig-2, stabilising Insig-2 and reducing lipid biosynthesis.

Electrochromic (EC) energy storage devices that could realize the multifunctional integration of energy storage and electrochromism have gained much recent attention. Herein, an EC battery based on the hybrid film of W18O49 and polyaniline (PANI) is developed and assembled, which integrates energy storage and EC functions in one device. The W18O49/PANI-EC battery delivers a discharging capacity of 52.96 mA h g−1, which is about two times higher than that of the W18O49-EC battery. Sunlight irradiation could greatly promote the oxidation reactions of both W18O49 and PANI during the charging process of the W18O49/PANI-EC battery, thus effectively accelerating the charging rate. This work provides a green, convenient, environmentally friendly, and cost-free charging strategy for the EC energy systems and could further advance the development of the multifunctional EC devices based on the organic/inorganic composites.

A montmorillonite@chitosan-poly (ethylene oxide) nanofibrous membrane (MMT@CPF) enhancing poly (vinyl alcohol-co-ethylene) (EVOH-MMT@CPF) composite film was developed by using a space-filling embedding method. The structure of EVOH-MMT@CPF was characterized, and the thermal stability, mechanical and barrier properties of the films were investigated. The CPF was fabricated via electrospinning technique and the self-assembly of MMT nano-platelets on CPF was achieved by the driving of electrostatic interactions between MMT nano-platelet and CPF. The experimental results indicated that the well-kept MMT@CPF after embedding in the EVOH matrix significantly improved the thermal stability and mechanical properties of the film, and also endowed the film with outstanding oxygen barrier (0.2 × 10−16 cm3 cm cm−2 s−1 Pa−1) and good moisture barrier (4.6 × 10−6 g m m−2 s−1 atm−1 under a relative humidity of 90%) by prolonging the tortuous paths for molecule penetration. The composite film may have a great potential application in food packaging.

Polyaniline/cerium dioxide (PANI/CeO2) nanocomposite (NPs) was synthesized by in situ polymerization of aniline in the presence of CeO2 NPs. Various analytical facilities, i.e., powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (HRTEM), were utilized to characterize the synthesized CeO2 and PANI/CeO2 NPs. The coatings prepared from the synthesized PANI/CeO2 NPs exhibited excellent corrosion resistance that was superior to epoxy coatings added with PANI in NaCl solution. The exceptional improvement of corrosion protection performance of the PANI/CeO2 /epoxy coatings is associated with the synergetic protection of the enhancement of the protective barrier due to the role of CeO2 NPs and PANI against the diffusion of aggressive ions (e.g., Cl−) and the improvement of self-healing protection attributed to the redox behavior of PANI. Thus, the hybrid PANI/CeO2 NPs are considered as the best route to enhance the protection performance of the epoxy coatings on carbon steel.

Recently, molybdenum disulfide functionalized with poly-ethylene glycol (PEGylated MoS2) has been widely used as a new drug delivery vehicle in biomedical field. However, the weak antibacterial activity of PEGylated MoS2 limits its application as an antibacterial agent. In this work, a novel silkworm-like conjugate of nisin loaded PEGylated MoS2 (nisin@PEGylated MoS2) was developed for antibacterial application. The morphology and structure of PEGylated MoS2 were strongly dependent on the Mo/S molar ratio of precursors during the solvothermal process. The silkworm-like skeleton was well kept after loading with nisin. A high level of reactive oxygen species (ROS) induced by the conjugate was an important cause of bacteria death. Due to the different structure of cell membranes, the sharp edges could more easily puncture into Escherichia coli (E. coli) as compared with Staphylococcus aureus (S. aureus) and produced more intracellular ROS, which improved the antibacterial activity of nisin against E. coli. As a result, nisin@PEGylated MoS2 displayed the antibacterial activity against both gram-positive and gram-negative bacteria. Furthermore, the toxicity of the conjugate was very low. Therefore, the target conjugate of nisin@PEGylated MoS2 may have great potential application as an antibacterial agent.

The effect of single-layer graphene sheets (Gr) on the corrosion protection of zinc-rich epoxy primers (ZRPs) was investigated. Scanning electron microscopy (SEM) with an energy dispersive spectrometer (EDS) were used to characterize morphology and composition of the coatings after immersion for 25 days. The cross-sectional SEM images and X-ray photoelectron spectroscopy (XPS) confirmed that the addition of single-layer graphene facilitated assembling of zinc oxides on the interface between the coating and the steel. The open circuit potential (OCP), electrochemical impedance spectroscopy (EIS) measurements revealed that both the cathodic protection and barrier performance of the ZRP were enhanced after addition of 0.6 wt. % Gr (Gr0.6-ZRP). In addition, the cathodic protection property of the Gr0.6-ZRP was characterized quantitatively by localized electrochemical impedance spectroscopy (LEIS) in the presence of an artificial scratch on the coating. The results demonstrate that moderate amounts of single-layer graphene can significantly improve corrosion resistance of ZRP, due to the barrier protection and cathodic protection effects.

In this work, p-hydroxybenzenesulfonic acid-formaldehyde resin acid catalyst (MSPFR), was synthesized by a hydrothermal method, and employed for the furfural production from raw corn stover. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 adsorption-desorption, elemental analysis (EA), thermogravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FT-IR) were used to characterize the MSPFR. The effects of reaction time, temperature, solvents and corn stover loading were investigated. The MSPFR presented high catalytic activity for the formation of furfural from corn stover. When the MSPFR/corn stover mass loading ratio was 0.5, a higher furfural yield of 43.4% could be achieved at 190 °C in 100 min with 30.7% 5-hydroxymethylfurfural (HMF) yield. Additionally, quite importantly, the recyclability of the MSPFR for xylose dehydration is good, and for the conversion of corn stover was reasonable.