Synthesis, structures, and phase transitions of barium bismuth iridium oxide perovskites Ba2BiIrO6 and Ba3BiIr2O9.

The Ba-Bi-Ir-O system is found to contain two distinct perovskite-type phases a rock-salt ordered double perovskite Ba2BiIrO6, and a 6H-type hexagonal perovskite Ba3BiIr2O9 Ba2BiIrO6 undergoes a series of symmetry-lowering phase transitions on cooling Fm (3) over barm -> R (3) over barc -> 12/m(C2/m)->/(1) over bar (P (1) over bar), all of which are second order except the rhombohedral monoclinic one, which is first order The monoclinic phase is only observed in a 2-phase rhombohedral+monoclinic regime. The transition and 2-phase region lie very close to 300K, making the room-temperature X-ray diffraction patterns extremely complex and potentially explaining why Ba2BiIrO6 had not previously been identified and reported A solid solution Ba2Bi1+xIr1-xO6, analogous to Ba2Bi1+xRu1-xO6, 0 C2/c at 750K, unlike 6H-type Ba3LaIr2O9, the P6(3)/mmc structure of which is highly strained below similar to 750K but fails to distort coherently to the monoclinic phase. © 2010, Elsevier Ltd

Drug-resistant colon cancer cells produce high carcinoembryonic antigen and might not be cancer-initiating cells

Hsin-chung Lee,1,2 Qing-Dong Ling,1,3 Wan-Chun Yu,4 Chunh-Ming Hung,4 Ta-Chun Kao,4 Yi-Wei Huang,4 Akon Higuchi3–51Graduate Institute of Systems Biology and Bioinformatics, National Central University, Jhongli, Taoyuan, 2Department of Surgery, Cathay General Hospital, Da'an District, Taipei, 3Cathay Medical Research Institute, Cathay General Hospital, Hsi-Chi City, Taipei, 4Department of Chemical and Materials Engineering, National Central University, Jhongli, Taoyuan, Taiwan; 5Department of Reproduction, National Research Institute for Child Health and Development, Okura, Tokyo, JapanPurpose: We evaluated the higher levels of carcinoembryonic antigen (CEA) secreted by the LoVo human colon carcinoma cells in a medium containing anticancer drugs. Drug-resistant LoVo cells were analyzed by subcutaneously xenotransplanting them into mice. The aim of this study was to evaluate whether the drug-resistant cells isolated in this study were cancer-initiating cells, known also as cancer stem cells (CSCs).Methods: The production of CEA was investigated in LoVo cells that were cultured with 0–10 mM of anticancer drugs, and we evaluated the increase in CEA production by the LoVo cells that were stimulated by anticancer drug treatment. The expression of several CSC markers in LoVo cells treated with anticancer drugs was also evaluated. Following anticancer drug treatment, LoVo cells were injected subcutaneously into the flanks of severe combined immunodeficiency mice in order to evaluate the CSC fraction.Results: Production of CEA by LoVo cells was stimulated by the addition of anticancer drugs. Drug-resistant LoVo cells expressed lower levels of CSC markers, and LoVo cells treated with any of the anticancer drugs tested did not generate tumors within 8 weeks from when the cells were injected subcutaneously into severe combined immunodeficiency mice. These results suggest that the drug-resistant LoVo cells have a smaller population of CSCs than the untreated LoVo cells.Conclusion: Production of CEA by LoVo cells can be stimulated by the addition of anticancer drugs. The drug-resistant subpopulation of LoVo colon cancer cells could stimulate the production of CEA, but these cells did not act as CSCs in in vivo tumor generation experiments.Keywords: drug treatment, colon cancer cell, 5-fluorouracil, stem cell, CD13

Synthesis and memory performance of a conjugated polymer with an integrated fluorene, carbazole and oxadiazole backbone

10.1038/pj.2011.114Polymer Journal443257-263POLJ