Tailed-Fe(2)O(3) ring arrays are fabricated by solution-dipping on a colloidal monolayer template. The influence of synthesis parameters on the quality of nanostructures has been investigated. The ring size can be controlled by changing the precursor concentration and varying the annealing time of the polystyrene sphere colloidal monolayer. In addition, the edge of the rings is sensitive to the surface tension of precursor solution, and high quality ordered ring arrays can be obtained by tuning the surface tension. This strategy allows the fabrication of specific metal oxides ring arrays with high quality and uniform morphology.

Room temperature ferromagnetism in pure ZnO is a very interesting phenomenon, but the reported intensity is usually as weak as 10 À2 to 10 À3 emu g À1 and the mechanism is still in debate. Here, we report room-temperature ferromagnetism as strong as 6.1 emu g À1 from un-doped ZnO ordered arrays fabricated by a colloidal template method, and show a remarkable dependence of such ferromagnetism on grain size for the first time. Interestingly, the M S of samples could be tuned over a large scale, from 0.1 to 6.1 emu g À1 by adjusting the annealing time. Further study shows that grain size and oxygen are dominant factors for such magnetism. When the grain size, in vacuum, increases from 3 to 15 nm, the M S decreases from 5.7 to 0.25 emu g À1 . For 3 nm grain size, ageing in the presence of oxygen, such as in air, for 1 week causes the M S to decrease to one-tenth of the original value. However, the M S of samples aged in vacuum does not change distinctly. Based on the observation and analysis of the above phenomena, we propose that oxygen vacancies at the surface of nanoparticles contribute to the ferromagnetism. This study could provide very simple and cheap semiconductor nanostructures with strong room temperature ferromagnetism for future spintronic applications and will deepen our understanding of the defect-related origin of such magnetism in ZnO.

ZrC and ZrB 2 were prepared by self-propagating high-temperature synthesis in a Cu-Zr-B 4 C system. We explored the influence of B 4 C particle size on the reaction process, phase composition and microstructure of the products. The results show that the production of ZrC and ZrB 2 is mainly controlled by the dissolution of B 4 C in Cu-Zr liquid. Increasing the size of B 4 C will not affect the reaction path, but will retard the formation of the Cu-Zr-B-C liquid. This leads to the incomplete conversion of ZrC and ZrB 2 once the B 4 C exceeds 28 m. In addition, ZrC and ZrB 2 particle sizes greatly decrease from the micrometer dimension with a polyhedral morphology to the nanometer scale with a nearly spherical shape.

Heart failure represents a major health problem. The development of new drugs to treat this condition is essential. We previously discovered that AF-001 attenuates the cardiac defects caused by heart failure in zebrafish. In this paper, we report the identification of AF-HF001, an AF-001 derivative, and its effects on live cardiomyocytes subjected to oxidative damage. The in vitro results demonstrated that AF-HF001 attenuates the production of reactive oxygen species (ROS) and the myocardial cell apoptosis. A DNA microarray was performed to broadly analyze gene expression after H 2 O 2 treatment with or without AF-HF001. Hierarchical clustering analysis revealed that AF-HF001 modifies the expression of certain genes (Ndufs2, Ndufb6, Ndufb8, Ndufa13, Ndufs3, Ndufs5, TPM1, MYH14, RyR1, and TIMP4) related to ROS production, cardiac contractility and extracellular matrix remodeling. AF-HF001 ameliorates oxidative damage, which may be related to the mitogen-activated protein kinase (MAPK) family and the intrinsic mitochondrial pathway. Altogether, this study suggests that AF-HF001 exhibits potential as a clinical drug candidate for the treatment of heart failure.

Room temperature ferromagnetism was observed in hole-like TiO2 nanostructure arrays prepared by a monolayer colloidal crystal template.