Hongyan Ding

Compared with the research on DNA damage, there are fewer studies on RNA damage, and the damage mechanism remains mostly unknown. Recent studies have shown that RNA is more vulnerable to damage than DNA when the cells are exposed to endogenous and exogenous insults. RNA injury may participate in a variety of disease occurrence and development. RNA not only has important catalytic functions and other housekeeping functions, it also plays a decisive role in the translation of genetic information and protein biosynthesis. Various kinds of stressors, such as ultraviolet, reactive oxygen species and nitrogen, can cause damage to RNA. It may involve in the development and progression of diseases. In this review, we focused on the relationship between the RNA damage and disease as well as the research progress on the mechanism of RNA damage, which is of great significance for the pathogenesis, diagnosis, and treatment of related diseases.

Poly(lactic acid) (PLA) and beta‐tricalcium phosphate (β‐TCP) are biodegradable biomaterials that can be used in the field of bone fixation. This article aims to investigate the effect of equal channel angular pressing (ECAP) on the mechanical property, physical properties and in vitro degradation behaviors of PLA/β‐TCP (0, 10, and 20 wt%) composites. The bending strength of PLA, PLA/10TCP, and PLA/20TCP composites processed by ECAP were 158, 154, and 137 MPa, respectively, which is higher than its initial samples by 62.8%, 32.7%, and 55.6%. The degradation experiment was carried out in Sorensen's phosphate‐buffered solution at 37°C for 24 weeks. The weight loss rate of PLA/β‐TCP composites processed by ECAP increased fastly but its mechanical property decreased slowly in contrast with hot‐pressed samples. With the degradation proceeding, the existence of β‐TCP resulted in the formation of whisker‐like hydroxyapatite on the surface of PLA/10TCP and PLA/20TCP composites. The oriented fiber structure of PLA matrix disappeared and its internal structure became loose after soaking for 24 weeks. The fiber structure of the PLA/β‐TCP composites formed in the process of ECAP not only increased the initial strength and the degradation rate, but also maintained the mechanical property of the samples in the degradation process. In the meanwhile, the existence of β‐TCP could inhibit the degradation of PLA matrix composites. This study on the in vitro degradation of self‐reinforced PLA/β‐TCP composites prepared by ECAP will provide theoretical support for the development of bone fixation.

In the history of nucleic acid research, DNA has always been the main research focus. After the sketch of the human genome was completed in 2000, RNA has been started to gain more attention due to its abundancies in the cell and its essential role in cellular physiology and pathologies. Recent studies have shown that RNAs are susceptible to oxidative damage and oxidized RNA is able to break the RNA strand, and affect the protein synthesis, which can lead to cell degradation and cell death. Studies have shown that RNA oxidation is one of the early events in the formation and development of neurodegenerative disorders, including Alzheimer’s disease, Parkinson’s disease, and amyotrophic lateral sclerosis. However, its molecular mechanism, as well as its impact on these diseases, are still unclear. In this article, we review the different types of RNA oxidative damage and the neurodegenerative diseases that are reported to be associated with RNA oxidative damage. In addition, we discuss recent findings on the association between RNA oxidative damage and the development of neurodegenerative diseases, which will have great significance for the development of novel strategies for the prevention and treatment of these diseases.

Ceramic coatings containing hydroxyapatite (HA) were fabricated on a biodegradable Mg₆₆Zn₂₉Ca₅ magnesium alloy through micro-arc oxidation by adding HA particles into the electrolytes. The phase composition and surface morphology of the coatings were characterized by X-ray diffraction and scanning electron microscopy analyses, respectively. Electrochemical experiments and immersion tests were performed in Hank’s solution at 37 °C to measure the corrosion resistance of the coatings. Blood compatibility was evaluated by in vitro blood platelet adhesion tests and static water contact angle measurement. The results show that the typical ceramic coatings with a porous structure were prepared on the magnesium alloy surface with the main phases of MgO and MgSiO₃ and a small amount of Mg₃(PO₄)₂ and HA. The optimal surface morphology appeared at HA concentration of 0.4 g/L. The electrochemical experiments and immersion tests reveal a significant improvement in the corrosion resistance of the ceramic coatings containing HA compared with the coatings without HA or bare Mg₆₆Zn₂₉Ca₅ magnesium alloy. The static water contact angle of the HA-containing ceramic coatings is 18.7°, which is lower than that of the coatings without HA (40.1°). The in vitro blood platelet adhesion tests indicate that the HA-containing ceramic coatings possess improved blood compatibility compared with the coatings without HA. Utilizing HA-containing ceramic coatings may be an effective way to improve the surface biocompatibility and corrosion resistance of magnesium alloys.

Owing to excellent mechanical property and biodegradation, magnesium-based alloys have been widely investigated for temporary implants such as cardiovascular stent and bone graft; however, the fast biodegradation in physiological environment and the limited surface biocompatibility hinder their clinical applications. In the present study, magnesium alloy was treated by sodium hydroxide (NaOH) and hydrogen fluoride (HF) solutions, respectively, to produce the chemical conversion layers with the aim of improving the corrosion resistance and biocompatibility. The results of attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS) indicated that the chemical conversion layers of magnesium hydroxide or magnesium fluoride were obtained successfully. Sodium hydroxide treatment can significantly enhance the surface hydrophilicity while hydrogen fluoride treatment improved the surface hydrophobicity. Both the chemical conversion layers can obviously improve the corrosion resistance of the pristine magnesium alloy. Due to the hydrophobicity of magnesium fluoride, HF-treated magnesium alloy showed the relative better corrosion resistance than that of NaOH-treated substrate. According to the results of hemolysis assay and platelet adhesion, the chemical surface modified samples exhibited improved blood compatibility as compared to the pristine magnesium alloy. Furthermore, the chemical surface modified samples improved cytocompatibility to endothelial cells, the cells had better cell adhesion and proliferative profiles on the modified surfaces. Due to the excellent hydrophilicity, the NaOH-treated substrate displayed better blood compatibility and cytocompatibility to endothelial cells than that of HF-treated sample. It was considered that the method of the present study can be used for the surface modification of the magnesium alloy to enhance the corrosion resistance and biocompatibility.

A new method for ortho‐cyanation of arylphosphonates is described.

The two suction foundation platforms installed in the Bohai Sea have vertical narrow columns passing through the water level. The continuous ice crushing on the columns and thereby the dynamic ice-structure interaction may usually happen during the ice season resulting in sustained violent vibrations of the structures. The paper first introduces the ice-induced vibration analysis of the suction foundation platform by using the self-excited vibration theory. Then the maximum dynamic shear stresses in the soil induced by ice are obtained from the analyses. By comparing the dynamic stresses to the cyclic strength of soil, which can be determined according to soil characteristics and features of the dynamic loading, the potential soil liquefaction is finally assessed.