Reduced chemically modified graphene oxide for supercapacitor electrode

An efficient active material for supercapacitor electrodes is prepared by reacting potassium hydroxide (KOH) with graphene oxide followed by chemical reduction with hydrazine. The electrochemical performance of KOH treated graphene oxide reduced for 24 h (reduced chemically modified graphene oxide, RCMGO-24) exhibits a specific capacitance of 253 F g(-1) at 0.2 A g(-1) in 2 M H2SO4 compared to a value of 141 F g(-1) for graphene oxide reduced for 24 h (RGO-24), and good cyclic stability up to 3,000 cycles. Interestingly, RCMGO-24 demonstrated a higher specific capacitance and excellent cycle stability due to its residual oxygen functional groups that accelerate the faradaic reactions and aid in faster wetting. This non-annealed strategy offers the potential for simple and cost-effective preparation of an active material for a supercapacitor electrode.

Recent progress and applications of cellulose and its derivatives-based humidity sensors: A review

Cellulose and its derivatives, which are low-cost, degradable, reproducible and highly hydrophilic, can serve as both substrate and humidity sensitive materials, making them more and more popular as ideal biomimetic materials for humidity sensors. Benefiting from these characteristics, cellulose-based humidity sensors cannot only exhibit high sensitivity, excellent mechanical performance, wide humidity response range, etc., but also can be applied to fields such as human health, medical care and agricultural product safety monitoring. Herein, cellulose-based humidity sensors are first classified according to the different conductive active materials, such as carbon nanotubes, graphene, electrolytes, metal compounds, and polymer materials, based on which the latest research progress is introduced, and the roles of different types of conductive materials in cellulose-based humidity sensors are analyzed and summarized. Besides, the similarities and differences in their working mechanisms are expounded. Finally, the application scenarios of cellulose-based humidity sensors in human movement respiration and skin surface humidity monitoring are discussed, which can make readers quickly familiarize the current preparation method, working mechanism and subsequent development trend of cellulose-based humidity sensors more effectively.

Enhancement of a hybrid colorimetric film incorporating Origanum compactum essential oil as antibacterial and monitor chicken breast and shrimp freshness

Recently, intelligent packaging has combined several functions, including monitoring and preserving food freshness in real-time. This study was developed a hybrid film (active/ colorimetric) based on AM/CPC/9%SFW as a carrier of Origanum compactum essential oil (OC) in various concentrations (0%, 1%, 1.25%, and 1.5% v/v). The film's emulsions showed homogeneity regarding particle size, polydispersity index, and ζ -potential. Hybrid films' morphological, mechanical, water and light barrier, thermal, and antioxidant properties were enhanced with an increased OC. Interestingly, all films rapidly responded to pH/NH3 and reflected different colors. In the hybrid films, an inhibition effect against gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli) bacteria and OC (1.5%) film exhibited a large inhibition zone attained diameters of 37.33 and 15.67 mm, respectively, in the disc diffusion test. Outstanding, AM/CPC/9%SFW/1.5 %OC film displayed the ability to preserve and monitor chicken breast and shrimp freshness to 33 and 21 h, respectively, during storage at 25 °C.

Ethylene scavenging properties from hydroxypropyl methylcellulose-TiO2 and gelatin-TiO2 nanocomposites on polyethylene supports for fruit application

Several technologies have been proposed to preserve fruits and to avoid postharvest losses. The degradation of ethylene produced by the fruits using TiO₂ photocatalysis has shown to be a good option to delay the ripening of fruits. This paper proposed a new application of biopolymers-TiO₂ nanocomposites developed to extend the shelf-life of fruits. Photocatalytic coatings were applied on the expanded polyethylene foam nets to degrade ethylene. Gelatin and hydroxypropyl methylcellulose (HMPC) were tested as hydrophobic and hydrophilic matrices for the TiO₂ incorporation. First, nanocomposite films prepared by casting were evaluated with regards to their photocatalytic properties. Both matrices, which were loaded with 1 wt% TiO₂, degraded 40% of the ethylene injected in a batch reactor. By Langmuir-Hinshelwood model, ethylene degradation using gelatin-TiO₂ films (k_app = 0.186 ± 0.021 min^-1) was faster than the HPMC-TiO₂ films (k_app = 0.034 ± 0.003 min^-1). Then, gelatin-TiO₂ dispersion was applied as a coating on the foam nets by dip coating. The gelatin-TiO₂ bilayer exhibited higher concentration of ethylene degraded per photocatalytic area and photocatalyst mass unit (13.297 ± 0.178 ppmv m² [Formula: see text] ) than its film form (18.212 ± 1.157 ppmv m² [Formula: see text] ), which makes gelatin-TiO₂/foam nets a promising composite design for fruit postharvest application.

Effective components and mechanism analysis of anti-platelet aggregation effect of Justicia procumbens L

ETHNOPHARMACOLOGICAL RELEVANCE

Justicia procumbens L. is a traditional Chinese medicine, first recorded in "Shen Nong's Herbal Classic", for the treatment of lumbar pain and fever. As a widely distributed herb, it has also been documented in India, Nepal, and Malaysia. In "Tang Materia Medica", a famous medicinal book of Tang Dynasty in ancient China, it was first used to treat diseases associated with blood stasis. Blood stasis syndrome is closely related to thrombus formation and platelet aggregation. Although some compounds isolated from this plant have anti-platelet aggregation effects, the main chemical components and mechanism of J. procumbens in terms of these effects are little known.

AIMS OF THE STUDY

Through in vivo and in vitro experiments, this studsy revealed the characteristic components and action mechanism of anti-platelet aggregation by J. procumbens from an overall perspective.

MATERIALS AND METHODS

The effective crude extracts of the whole plant were screened via an in vitro anti-platelet aggregation test. After incubating these extracts with apheresis platelets, high affinity compounds were detected by HPLC-MS and regulatory genes were detected using gene chips. The effective components and potential target proteins were analyzed using computational docking technology. Furthermore, the compound with the strongest predicted activity was evaluated in vivo via an anti-thrombotic test.

RESULTS

Integrin a_Ⅱbβ₃, PKCα, PI3Kγ, and mitogen-activated protein kinase 14 were found to be potential targets. Justicidin B, tuberculatin, chinensinaphthol methyl ether, and neojusticin B were effective compounds that inhibited human platelet aggregation by suppressing Gq-PLC-PKC and Gi-PI3K-MAPK signaling pathways. Among the compounds that bind to platelets, justicidin B showed the strongest virtual binding force. The test of carotid artery thrombosis induced by ferric chloride in SD rats confirmed that justicidin B inhibited thrombus formation.

CONCLUSION

Experimental investigation showed that arylnaphthalene lignan aglycones with one methylenedioxy group and two methoxy groups are effective components for anti-platelet aggregation by J. procumbens. These compounds inhibit Gq-PLC-PKC and Gi-PI3K-MAPK signaling pathways by suppressing the expression of genes such as ITGB3, PRKCA, PIK3CG, and MAPK14. These results reflected the characteristics of multi-component and multi-target synergistic treatment of Chinese medicine.

Cathode active materials using rare metals recovered from waste lithium-ion batteries: A review

Large-scale lithium-ion batteries (LIBs) are overtaking as power sources for electric vehicles and grid-scale energy-storage systems for renewable sources. Accordingly, large amounts of LIBs are expected to be discarded in the near future. Recycling technologies for waste LIBs, particularly for valuable rare metals (Li, Co, and Ni) used in cathode active materials, need to be developed to construct continuous LIB supply chains. Various recovery methodologies, such as pyrometallurgy, hydrometallurgy, and direct recycling, as well as their advantages, disadvantages, and technical features, are briefly introduced. We review the electrochemical performances of these cathode active materials based on recycled rare metals from LIB waste. Moreover, the physicochemical properties and electrochemical performance of the cathode active materials with impurities incorporated during recycling, which have high academic significance, are outlined. In hydrometallurgy-based LIB recycling, the complete removal of impurities in cathode active materials is not realistic for the mass and sustainable production of LIBs; thus, optimal control of the impurity levels is of significance. Meanwhile, the studies on the direct recycling of LIB showed the necessity of almost complete impurity removal and restoration of physicochemical properties in cathode active materials. This review provides a survey of the technological outlook of reusing cathode active materials from waste LIBs.