Increased activity of CHK enhances the radioresistance of MCF-7 breast cancer stem cells.

The resistance of breast cancer to radiotherapy remains a major obstacle to successful cancer management. Radiotherapy may result in DNA damage and activate breast cancer stem cells. DNA damage may lead to activation of the checkpoint kinase (CHK) signaling pathway, of which debromohymenialdisine (DBH) is a specific inhibitor.

PH-controlled construction of Cu(I) coordination polymers: in situ transformation of ligand, network topologies, and luminescence and UV-vis-NIR absorption properties.

Two new complexes [Cu(I)(3)(L1)I(3)](n) (1, L1 = 2,5-bis(4-pyridyl)-1,3,4-oxadiazole) and [Cu(I)(3)(L2)I(2)](n) (2, L2 = 2,5-bis(4-pyridyl)-1,2,4-triazolate) are controllably formed by using aqueous ammonia to regulate the pH value of the reaction involving CuI and L1. Interestingly, L2 of 2 is in situ generated from the ring transform of L1 when increase the pH value of the reaction. 1 exhibits 2-D layer, while 2 shows 3-D MOFs with a novel 3-nodal 4,4,5-connected net topology of an unprecedented Point (Schlafli) symbol: (4·5(2)·6(2)·7)(5(4)·8(2))(4(3)·5·6(6)).

Structural, luminescent, and magnetic properties of three novel three-dimensional metal-organic frameworks based on hexadentate N,N'-bis(4-picolinoyl)hydrazine.

Three novel microporous three-dimensional (3-D) metal-organic framework materials [ML](n) [M = Ni, Co, Cd; L = N,N'-bis(4-picolinoyl)hydrazine] were obtained from hydrothermal reactions. The organic ligand L was formed through the in situ ring-opening hydrolysis reaction of 2,5-bis(4-pyridyl)-1,3,4-oxadiazole with the assistance of metal ions. Single-crystal X-ray diffraction studies reveal that complexes 1-3 adopt 6-connected 3-D networks of distorted alpha-Po topology, which are built from non-interpenetrated (4,4) grids cross-linked by zigzag chains.