RESUMO
The current anticorrosion strategy makes use of coatings to passively protect the steel, which faces increasing challenge due to the tightened environmental regulations and high cost. This paper reports a new method for achieving a super anticorrosion function in Al-Si alloys through Mg nano-metallurgy, which was characterized by real-time synchrotron measurements. The unique function is based on the formation of an amorphous and self-charge-compensated MgAl2O4-SiO2 phase between the grain boundaries to help prevent the penetration of oxygen species through the grain boundaries. Through this, the corrosion resistance of pristine aluminized steel could be improved almost 20 fold. An analysis of the phases, microstructures of the Mg-coated aluminized layer and corrosion products consistently supported the proposed mechanism. This charge-compensated corrosion resistance mechanism provides novel insight into corrosion resistance.
RESUMO
Mitochondrial dynamics greatly influence the biogenesis and morphology of mitochondria. Mitochondria are particularly important in neurons, which have a high demand for energy. Therefore, mitochondrial dysfunction is strongly associated with neurodegenerative diseases. Until now various post-translational modifications for mitochondrial dynamic proteins and several regulatory proteins have explained complex mitochondrial dynamics. However, the precise mechanism that coordinates these complex processes remains unclear. To further understand the regulatory machinery of mitochondrial dynamics, we screened a mitochondrial siRNA library and identified mortalin as a potential regulatory protein. Both genetic and chemical inhibition of mortalin strongly induced mitochondrial fragmentation and synergistically increased Aß-mediated cytotoxicity as well as mitochondrial dysfunction. Importantly we determined that the expression of mortalin in Alzheimer disease (AD) patients and in the triple transgenic-AD mouse model was considerably decreased. In contrast, overexpression of mortalin significantly suppressed Aß-mediated mitochondrial fragmentation and cell death. Taken together, our results suggest that down-regulation of mortalin may potentiate Aß-mediated mitochondrial fragmentation and dysfunction in AD.