We study the extended Su-Schrieffer-Heeger model with both the nearest-neighbor and nextnearest-neighbor hopping strengths being cyclically modulated and find the family of the model system exhibiting topologically nontrivial phases, which can be characterized by a nonzero Chern number defined in a two-dimensional space spanned by the momentum and modulation parameter. It is interesting that the model has a similar phase diagram as the well-known Haldane's model. We propose to use photonic crystal systems as the idea systems to fabricate our model systems and probe their topological properties. Some other models with modulated on-site potentials are also found to exhibit similar phase diagrams and their connection to the Haldane's model is revealed.

The purpose of this study is to evaluate neuroprotective effects of (-)-Epigallocatechin-3-gallate (EGCG) in a transgenic mouse model of Amyotrophic lateral sclerosis (ALS). SOD1-G93A transgenic mice and wild-type mice were randomly divided into EGCG-treated groups (10 mg/kg, p.o) and vehicle-treated control groups. Rotarod measurement was performed to assess the motor function of mice starting at the age of 70 days. Nissl staining to examine the number of motor neurons and CD11b immunohistochemical staining to evaluate activation of microglia in the lumbar spinal cords were conducted at the age of 120 days. In addition, for further observation of regulation of cell signaling pathways by EGCG, we used immunohistochemical analysis for nuclear factor kappa B (NF-kappaB) and cleaved caspase-3 as well as western blot analysis to determine the expression of nitric oxide synthase (iNOS) and NF-kappaB in the spinal cord. This study demonstrated that oral administration of EGCG beginning from a pre-symptomatic stage significantly delayed the onset of disease, and extended life span. Furthermore, EGCG-treated transgenic mice showed increased number of motor neurons, diminished microglial activation, reduced immunohistochemical reaction of NF-kappaB and cleaved caspase-3 as well as reduced protein level of iNOS and NF-kappaB in the spinal cords. In conclusion, this study provides further evidences that EGCG has multifunctional therapeutic effects in the mouse model of ALS.