Layer Hall effect induced by hidden Berry curvature in antiferromagnetic insulators.

The layer Hall effect describes electrons spontaneously deflected to opposite sides at different layers, which has been experimentally reported in the MnBi2Te4 thin films under perpendicular electric fields. Here, we reveal a universal origin of the layer Hall effect in terms of the so-called hidden Berry curvature, as well as material design principles. Hence, it gives rise to zero Berry curvature in momentum space but non-zero layer-locked hidden Berry curvature in real space. We show that, compared to that of a trivial insulator, the layer Hall effect is significantly enhanced in antiferromagnetic topological insulators. Our universal picture provides a paradigm for revealing the hidden physics as a result of the interplay between the global and local symmetries, and can be generalized in various scenarios.

Finite-size effect on quantum percolation in topological insulators.

We study the finite-size effect on quantum percolation in two-dimensional topological insulators. We demonstrate that the percolation threshold in topological insulators strongly depends on the localization length of the edge states in small clusters due to the finite-size effect. Also, we explain why the percolation threshold in the corresponding classical model determines the lower bound of the quantum percolation threshold in topological insulators. In addition, we extend the percolation model to a more general scenario, where the system is composed of both topological and trivial clusters. We find that the quantum percolation threshold can be less than the classical percolation threshold due to quantum tunneling of the edge states.

MiR-1-5p is down-regulated in gallbladder carcinoma and suppresses cell proliferation, migration and invasion by targeting Notch2.

BACKGROUND: Numerous studies have demonstrated that aberrant microRNAs (miRNAs) are involved in tumorigenesis and tumor progression. Nevertheless, the precise role of miR-1-5p in gallbladder carcinoma cell growth and metastasis remains not fully revealed. MATERIAL AND METHODS: The levels of miR-1-5p were detected in gallbladder carcinoma tissues and cell lines using qRT-PCR method. A series of functional assays, including cell proliferation, colony formation, wound healing and Transwell invasion were conducted using miR-1-5p or miR-1-5p inhibitor transfected cells. RESULTS: MiR-1-5p was remarkably down-regulated in gallbladder carcinoma tissues and cell lines compared to normal. In addition, over-expression of miR-1-5p markedly suppressed the growth, migration and invasion of gallbladder carcinoma cell. Conversely, down-expression of miR-1-5p facilitated gallbladder carcinoma cell proliferation and aggressiveness. Mechanistic investigations demonstrated that neurogenic locus notch homolog protein 2 (Notch2) was the directly target of miR-1-5p and Notch2 mediated the inhibitory effect of miR-1-5p in gallbladder carcinoma cell growth and aggressiveness. CONCLUSION: Our findings demonstrated that miR-1-5p acted as a suppressive miRNA and played vital roles in the growth, migration and invasion of gallbladder carcinoma cell through targeting Notch2.