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The hollow core–shell structure ZnFe2O4@C in this work has excellent EM absorption performance.

In order to realize the characteristics of new types of wave-absorbing materials, such as strong absorption, broad bandwidth, low weight and small thickness, a hollow-structured flower-like Fe3O4@MoS2 composite was successfully prepared by simple solvothermal and hydrothermal methods in this paper. The structural properties were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Besides, the microwave properties and magnetic properties were measured using a vector network analyzer and via a hysteresis loop. SEM and TEM images revealed that MoS2 nanosheets grew on the surface of hollow nanospheres. The results showed that the composite exhibited excellent absorbing property. When the molar ratio of Fe3O4 and MoS2 was 1 : 18, the minimum reflection loss value reached −49.6 dB at 13.2 GHz with a thickness of 2.0 mm and the effective absorption bandwidth was 4.24 GHz (11.68–15.92 GHz). Meanwhile, the effective absorption in the entire X-band (8–12 GHz) and part of the C-band (4–8 GHz) and Ku-band (12–18 GHz) could be achieved by designing the sample thickness. In addition, the hollow structure effectively reduced the density of the material, which was in line with the current development trend of absorption materials. It could be predicted that the hollow core–shell structure composite has a potential application prospect in the field of microwave absorption.

The special hollow core-shell structure and excellent dielectric-magnetic loss synergy of composite materials are two crucial factors that have an important influence on the microwave absorption properties. In this study, hollow ZnFe

Cu–Bi co-doped ZnO nanospheres were obtained by adopting Bi and Cu to dope ZnO to improve their photocatalytic performance in the visible region. Cu–Bi co-doped ZnO nanospheres were successfully grown on the surface of cotton fabric by a sol–gel assisted hydrothermal method with citric acid as a morphology control agent. The obtained products were characterized by X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and diffuse reflectance spectroscopy (DRS). The results showed that the size of ZnO nanospheres was about 200 nm and doping with Cu and Bi did not change their morphology. Cu–Bi co-doped ZnO nanospheres presented a hexagonal wurtzite structure with high crystallinity; meanwhile, their band gap was also obviously reduced due to doping, from 3.24 eV to 2.82 eV. Cu–Bi co-doped ZnO nanospheres endowed the cotton fabric with excellent UV (ultraviolet) resistance with a UPF (Ultraviolet Protection Factor) value of 283.54 after 40 washes. Cotton fabric with 3% Bi–5% Cu co-doped ZnO on the surface showed 98.66% degradation of methylene blue (MB) solution under visible light irradiation for 150 min, indicating remarkable photocatalytic performance.

In order to realize the characteristics of new types of wave-absorbing materials, such as strong absorption, broad bandwidth, low weight and small thickness, a hollow-structured flower-like Fe

Superabsorbent polymers as soft materials that can absorb water have aroused great interest in the fields of agriculture and forestry. Water absorption and water retention performance of a hydrogel are important indicators to evaluate its practical application. However, few reports show that hydrogels have both excellent water absorption and water retention properties. To date, superabsorbent hydrogels with a swelling capacity of more than 3000 g g−1 have rarely been reported. In this work, a novel superabsorbent poly(acrylic acid) (PAA)-based nanocomposite hydrogel (NC gel) was prepared via free radical polymerization of acrylic acid by using vinyl hybrid silica nanospheres (VSNPs) as the cross-linking agent. The PAA NC hydrogel achieved a great swelling ratio of more than 5000 times in deionized water at 323 K, and the swollen hydrogel could hold 60% moisture when it was exposed to the air at 303 K for 42 h. Moreover, the hydrogel also obtained a good swelling ratio of 136 g g−1 in NaCl solution. The PAA NC hydrogel showed excellent repetitive swelling ability. The influences of variable factors (acrylic acid, initiator and sodium hydroxide) on the swelling ratio of the NC hydrogel were researched. It can be speculated that the PAA NC hydrogel has potential application in agriculture and forestry areas due to its excellent water absorption and water retention properties.

α-Synuclein (α-Syn) aggregates are the major component of Lewy bodies (LB), which is a pathological hallmark in the brain tissue of Parkinson's disease (PD) patients. It has been reported that (−)-epigallocatechin-3-gallate (EGCG) is biologically able to penetrate the blood–brain barrier and inhibit the fibrillation of amyloid proteins. This study aimed to provide insight into the possible mechanism of EGCG as a potential candidate agent for the prevention and treatment of PD on the basis of the interaction between α-Syn and EGCG. In the present study, the effects of EGCG on the fibrillation and disaggregation of α-Syn were investigated by thioflavin T (ThT) fluorescence spectroscopy, circular dichroism spectroscopy (CD), nuclear magnetic resonance (NMR) spectroscopy, atomic force microscopy (AFM) and transmission electron microscopy (TEM) on a molecular level. In addition, on the cellular level, we investigated the protective effects of EGCG on α-Syn-induced cell death in the transduced PC12 cells which overexpressed α-Syn, using the techniques of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, 2,7-dichlorodihydrofluorescein diacetate (DCFH-DA) assay, western blot and confocal laser scanning microscopy. It was found that EGCG not only significantly inhibited the conformational transition of α-Syn from random coil to β-sheet conformers through binding to Ile, Phe and Tyr amino residues, but also disaggregated the amyloid fibrils of α-Syn in a dose-dependent manner, through binding to Leu, His, Phe and Tyr amino residues. It is also demonstrated that EGCG can protect PC12 cells against α-Syn-induced damage by inhibiting the overexpression and fibrillation of α-Syn in the cells.

Abnormal denaturation and aggregation of human amylin or islet amyloid polypeptide (IAPP) into amyloid fibrils has been implicated in the pathogenesis of type 2 diabetic mellitus. Trehalose, a super-hydrophilic molecule, has been shown to prevent denaturation of biomolecules when they are under environmental stress. In this work, we sought to investigate the effects of trehalose on the fibrillation and aggregation of human IAPP (hIAPP) by using circular dichroism spectrum, thioflavin-T fluorescence spectrum, dynamic light scattering, transmission electronic microscopy, atomic force microscopy and quartz crystal microbalance. We demonstrated that (1) the conformation of hIAPP changed from α-helix to β-sheet, followed by fibrillation and aggregation, (2) a low dose of trehalose (under 100 mM) inhibited or delayed the conformation transition of hIAPP and (3) a high dose (more than 500 mM) induced the conformation transition, and promoted the fibrillation and aggregation of hIAPP. These findings are in agreement with the hypothesis of the water replacement and volume exclusion effect on the proteins. The lower concentration of trehalose could replace the water molecules surrounding the hIAPP, and interact with proteins through hydrogen bonding, leading to a reduction in the protein interaction itself, and therefore inhibiting or delaying the protein fibrillation and aggregation. In contrast, the higher concentration of trehalose might interact with itself to form macromolecular clusters, acting as a crowding agent, leading to the hIAPP molecules being excluded by the trehalose clusters and interacting between each other, and therefore promoting the hIAPP fibrillation and aggregation.