Microcystins are a kind of cyclic hepatoxins produced by many species of cyanobacteria. The toxic effects of microcystins on animals and plants have been well studied. However, the reports about the effects of microcystins on microbial cells are very limited. In present paper, Escherichia coli was undertaken to determine the effect of microcystin-RR. These results suggested that microcystin-RR could prolong the growth of E. coli when exposed to high concentrations of microcystin-RR and cause the accumulation of ROS and induce the oxidant stress for a short time. The antioxidant system protects E. coli from oxidative damage.

A nickel-base high-temperature alloy (Ni-17Mo-7Cr) has been characterized by nanoindentation and transmission electron microscopy to determine the changes of nanoindentation hardness and microstructural evolution under ion irradiation. Ion irradiation experiments for bulk and thin-foil specimens of Ni-17Mo-7Cr alloy were carried out at room temperature, up to 6.6 dpa, by 7 MeV Xe 26+ and 1 MeV Xe 20+ ions, respectively. The continuous stiffness measurement (CSM) with a diamond Berkovich indent was used to measure the depth profile of hardness. Nanoindentation results for bulk specimens showed an evident ion irradiation induced hardening phenomenon, and the nanoindentation hardness increases with increasing ion dose. High number density of nano-scale black spots and linear-like defects were observed in thin-foil specimens irradiated at 0.33 and 6.6 dpa, respectively. High-resolution transmission electron microscopy images revealed that the black spots were nanoscale solute clusters and dislocation loops, while the linear-like defects were found to be Ni, Mo and Cr-enrichment regions by using the highangle annular dark field-scanning transmission electron microscope. The ion irradiation induced defects can be responsible for the hardening of Ni-17Mo-7Cr alloys.

The effect of temperature on the evolution of loops in nickel was investigated under 30 keV He+ irradiation. The size, Burgers vector, and nature of loops were analyzed by a transmission electron microscope (TEM). In addition, the Weibull statistical analysis was introduced to analyze the size distributions of the loops. The TEM results indicate that the sizes of loops increase with increasing irradiation temperature, where they are mainly in the range of 10–30, 20–50, and 30–80 nm at 300, 400, and 500 °C, respectively. In the irradiation temperature range of 300–500 °C, the size distributions of loops fit Weibull distribution very well, which suggests that the loops tend to grow larger and/or be merged. In addition, almost all the loops formed under He+ irradiation are the interstitial loops with Burgers vectors b =  a2⟨110⟩, which is ascribed to the assistance of the He atom on the formation process of loops.