Ectopic expression of four transcription factors, including Oct4, Sox2, Klf4 and c-Myc, in differentiated fibroblast cells could reset the cell fate of fibroblast cells to pluripotent state [1]. Subsequently, full pluripotency of these so-called induced pluripotent stem cells (iPSCs) has been demonstrated, as viable mice could be generated autonomously from iPSCs through tetraploid blastocyst complementation [2,3]. Moreover, the generation of human and patient-specific iPSCs has raised the possibility of utilizing iPSCs clinically [4][5][6]. However, the utilization of c-Myc in iPSC induction greatly increased the incidence of tumorigenecity in the iPS-chimeric mice and also might hinder the clinical application of human iPSCs in the future [7]. Fortunately, c-Myc has been recently found dispensable for iPSC induction even though the induction efficiency is greatly reduced in the absence of c-Myc [7]. However, it remains unknown whether these three factor-induced iPSCs are fully pluripotent. In the present study, we have successfully demonstrated that three-factor iPSCs could also be fully pluripotent, as viable mice could be generated from three-factor iPSCs autonomously via tetraploid complementation and moreover, our data indicate that the pluripotency regulatory mechanism in three-factor iPSCs might be distinct from four-factor iPSCs.As previous described, we used Tet-on-inducible lentiviruses to transduce cDNAs of the three transcription factors Oct4, Sox2 and Klf4 into mouse embryonic fibroblast (MEF) cells to generate three-factor iPSCs [8,9]. The MEF cells were collected from the 13.5 d.p.c. embryos, which were generated by mating the OG2 (Oct4-GFP transgenic) mice with ROSA26-M2rtTA transgenic mice. After lentiviral infection, the MEF cells were cultured for 3 weeks in ES culture medium supplemented with doxycycline, subsequently, GFP-positive colonies appeared and then the doxycycline was withdrawn from the culture medium. After 3 days, ES-like colonies were picked and propagated individually ( Figure 1A). In total,

The calcium looping (CaL), which applies carbonation/calcination cyclic reactions of a CaO sorbent, has received extensive attention for postcombustion CO 2 capture. However, as the number of cyclic reactions increased, the capture efficiency of regenerated CaO decreased rapidly. Sodium doping was proposed for modification of a CaO sorbent, but there was little research on whether sodium doping had a good effect on different kinds of sorbents. In this paper, three different kinds of calcium-based sorbents, i.e., CaCO 3 , dolomite, and SG-CaO, were modified by NaBr to explore the effect of sodium on CO 2 capture performance. The results showed that the modification effects of sodium on three kinds of precursors were different. For CaCO 3 , the modification effect of sodium doping was the best. After 50 cycles, the sorption capacity of CaO/NaBr was over 3.5 times that of an unmodified sorbent; for dolomite, sodium had a moderate effect during initial cycles and then showed obvious improvement in the stability of the sorbent, the sorption capacity of the modified dolomite increased by over 30% after 50 cycles; for the SG-CaO, sodium had a negative effect, the sorption capacity of the modified sorbent decreased by about 30% after 50 cycles. When the atmosphere contained SO 2 , the doping of an alkali metal also showed a certain effect.

No abstract

No abstract

No abstract