Search

Free-standing flexible supercapacitive electrodes have practical application for wearable energy storage devices. In this paper, graphene paper (GP), a flexible electrode substrate, was prepared by one-step reduction of graphene oxide (GO) using HI solution. GP can be used independently as a flexible electrode with specific capacitance of 227 F/g. In order to make up for the shortage of GP specific capacitance storage, polyaniline (PANI) with high specific capacitance and good electrical conductivity was selected to composite with GP by electrochemical polymerization approach. This method to fabricate electrode material by direct electrochemical polymerization avoids the use of conductive binder and organic solvent. Owing to the specific capacitance contribution of PANI and GP, the PANI/GP composites exhibit higher specific capacitance when the polymerization time is 30 s and the polymerization voltage is 0.8 V. At 1 A/g current density, the specific capacitance of composite is up to 759 F/g, which is 3.34 times of neat GP.

Background Adriamycin (ADM) is one of the postoperative chemotherapy drugs for breast cancer (BCa) patients. Circular RNAs have been shown to modulate ADM resistance in many cancers. However, it is unclear whether circ_0006528 can modulate the ADM chemoresistance in BCa. Methods Levels of circ_0006528, microRNA-1236-3p (miR-1236-3p), and chromodomain helicase DNA-binding protein 4 (CHD4) were detected by quantitative real-time polymerase chain reaction or western blot. Cell proliferation, the half maximal inhibitory concentration (IC50) value of ADM, and cell migration and invasion were evaluated by cell counting kit-8 and transwell assays, respectively. The interaction among circ_0006528, miR-1236-3p, and CHD4 was confirmed using dual-luciferase reporter assays. Tumor formation in nude mice was performed to explore the effect of circ_0006528 in vivo. Results Higher levels of circ_0006528 and CHD4 and lower level of miR-1236-3p were found in ADM-resistant BCa tissues and cells, and patients with high circ_0006528 had a shorter overall survival. Circ_0006528 could directly bind to miR-1236-3p, and circ_0006528 knockdown or miR-1236-3p overexpression could suppress cell proliferation, migration, invasion, and ADM resistance in ADM-resistant BCa cells. Moreover, circ_0006528-regulated CHD4 expression by sponging miR-1236-3p, and CHD4 elevation reversed the inhibitory effect of circ_0006528 knockdown on ADM-resistant BCa cells. Consistently, circ_0006528 inhibition retarded ADM-resistant BCa tumor growth in vivo by decreasing CHD4 and increasing miR-1236-3p. Conclusions Downregulation of circ_0006528 restrained cell proliferation, migration, invasion, and drug resistance of ADM-resistant BCa cells through inhibiting CHD4 and inducing miR-1236-3p.

Conjugated covalent organic frameworks (COFs) with redox properties can be considered as conductive polymers with ordered porous structures and can be designed for photoelectric materials application. In this paper, 2,6-diaminoanthraquinone and 1,3,5-triformylresorcinol (DAAQ-TFP) COF with anthraquinone active unit was synthesized by solvothermal method for electrochromic application in a Teflon-lined autoclave. Functionalized graphene oxide (FGO) was covalently bonded with COF to improve its electrical conductivity and photoelectric properties. After the addition of FGO, the impedance of COF was reduced, and the optical contrast and cyclic stability of COF were increased. At potential windows of 2.5 V to -3.8V, the COF-FGO-2% can be switched reversible from orange to dark brown. Stability test shows that the contrast retention is 109.1% after 1800s switching, which is much higher than COF (75%). Considering the abundance of COF building units with redox activity available, it is possible to develop novel COF based electrochromic materials with rich colors.

In this paper, the geometric shape, dimension parameters and density of maize grains were studied to establish a DEM analysis model of maize assemblies. According to the results, the shape of maize grains of the same variety can be divided into wide wedge, narrow wedge, ellipsoidal-conical and irregular shapes. Amongst these shapes, the quantity of wide wedge and narrow wedge shapes accounts for more than 90% of the total. When modelling maize assemblies, wedge shaped maize can be chosen to establish a geometric model with the upper base defined as the main dimension and other dimensions calculated based on the relationship with the main dimension. The geometric model of single maize grains was established using a Multi-Sphere (MS) model. This analysis model of maize grain is acceptable for scenarios with 14–16 sub-spheres. On the basis of this work, 2 varieties of maize grains are used as examples. The feasibility and validity of the modelling method of maize assemblies and single maize grains are preliminarily verified through comparison of experimental and simulated data to determine repose angles and bulk density.

Soybean is considered as one of the most important cereal grains. The shape, size, physical and mechanical properties of soybean grains are playing a significant role in transportation, storage and processing. However, the study of these properties of soybean grains up to now is not systematic and in-depth. In this paper, three varieties of soybean grains are selected to determine and analyze these properties. Moreover, the effect of moisture content ranging from 8 % to 23 % on these properties is also studied. It is shown that the shape of soybean grains is approximate to ellipsoid. Three axial dimensions follow the normal distribution approximately, and they have certain functional relation between each other and have positive linear relation with moisture content. The parameters of the physical and mechanical properties have different variation laws with increase of moisture content. This paper can provide a reference to describe the characteristic of soybean grains group realistically and choose parameters in DEM simulations.

The geometrical shape and dimensions of maize grain group are investigated in this paper. It is shown that the shape of grains of the same variety can be generally divided into wide wedge shape, narrow wedge shape, ellipsoidal conical shape and irregular shape, respectively. Among them, the quantity of wide wedge shape and narrow wedge shape accounts for more than 90 %. The geometric model of wedge shaped maize grains can be established when modeling for grain group. The analysis model of single maize grain is established using the multi-sphere (MS) model. 2 varieties of maize grains are taken for example on the basis of above work. The feasibility and validity of the modeling method of maize grain group and single maize grain filling combination is verified preliminarily by comparing experimental results and simulation results. The study in this paper provides a certain reference basis for the relevant research.