Alternative splicing of medaka bcl6aa and its repression by Prdm1a and Prdm1b
Summary (2 min read)
Possible Mechanisms of Oxygen Exchange for Dual Phase Composites
- Oxygen exchange on dual-phase composites have been discussed by several groups as mentioned in the introduction.
- Different involvements of the two phases in the oxygen exchange were proposed.
- S1 is the surface area of the P1 phase, V1 is the volume of P1, t is time and k1 is the efficient surface exchange coefficient of the P1 phase.
- The kex-LSF (GB) and kex-CGO (GB) are the effective surface exchange coefficient on the single-phase grain boundaries and kex(TPB) is the effective surface exchange coefficient on the dual-phase grain boundaries (as illustrated in Figure 2II).
- The oxygen exchange on the “cleaned” CGO surface appears to be very fast,40 and possibly, in the older SIMS studies of single phase CGO the exchange reaction has been impeded by unintended impurities on CGO surface.
Experimental
- The sample was sintered at 1300◦C for 10 h to reach 97.4% of the theoretical density, polished and re-annealed at 1000◦C. Characterizations.
- Pt wires attached to both ends of the sample were used as current probes.
- By fitting the conductivity change using Fick’s law of diffusion with appropriate boundary conditions, the values of kex and Dchem can be obtained.
Results
- —The X-ray diffractograms of the pure LSF, the dual-phase LSF-CGO composites after sintering at 1300◦C and of the CGO powder are shown in Figure 3.
- The total conductivity of the composites is lower than that of the pure LSF, due to much lower total conductivity of CGO (Table I).
- At 750◦C the measured values correspond well to the calculated one with τIC of 1 for the CGO70 sample, whereas τIC of 2.5 and 20 were used for the CGO50 and CGO30 samples, respectively (Figure 8B) to match the measured and calculated Dchem values.
- Assuming that oxygen exchange may also occur on the CGO, the effective kex(cal) was calculated according to Eq. 3, where the kex(CGO) was selected as to give a best fit of Eq. 3 to the measured values for different temperatures and pO2’s.
Discussion
- In case of pure LSF the surface exchange reaction at high pO2’s (10−3 < pO2 < 1 atm), by assuming the involvement of oxygen vacancies in the oxygen surface exchange process,10 will be strongly depended on the mobility and/or concentration of oxygen vacancies, while for pure CGO the oxygen exchange will be presumably limited by the electronic conductivity.
- Hence, it could be, that a cleaning of the CGO surface takes place via the presence of LSF, making the oxygen exchange on CGO much faster than when considering single phase CGO samples.
- It should also be pointed out that these two mechanisms are not mutually exclusive and can act simultaneously. ) unless CC.
- Further, the pO2 dependence of kex, which was observed to vary with the CGO fraction and the temperature, can point out different aspects of the mechanism of the oxygen exchange.
- At 750◦C the measured values for the CGO70 sample behaves as expected from the materials properties and increasing the LSF fraction leads to large deviations from the values obtained by volume weighting average, which is interpreted as a tortuosity effect.
Conclusions
- Considering all experimental data it is further suggested that the rds is temperature and composition dependent.
- The involvement of CGO in the oxygen exchange can be through the spillover of oxygen ions, partly reduced oxygen species, from LSF to CGO, where they dissociate and/or incorporate.
- An alternative effect could be that the LSF scavenges impurities from CGO and thereby activates the CGO surface for the oxygen surface exchange reaction.
- Both proposed mechanism could account for the observations.
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References
138 citations
"Alternative splicing of medaka bcl6..." refers background in this paper
...Prdm1 can bind a motif, GAAAG of the genes, c-myc (Kuo and Calame 2004; Shaffer et al. 2002), IFN-β (Kuo and Calame 2004), Pax-5 (Kuo and Calame 2004), Spi-B (Kuo and Calame 2004; Shaffer et al. 2002), Id3 (Kuo and Calame 2004; Shaffer et al. 2002), ifng (Cimmino et al. 2008), and tbx21 (Cimmino et…...
[...]
...…bind a motif, GAAAG of the genes, c-myc (Kuo and Calame 2004; Shaffer et al. 2002), IFN-β (Kuo and Calame 2004), Pax-5 (Kuo and Calame 2004), Spi-B (Kuo and Calame 2004; Shaffer et al. 2002), Id3 (Kuo and Calame 2004; Shaffer et al. 2002), ifng (Cimmino et al. 2008), and tbx21 (Cimmino et al.…...
[...]
...Prdm1 can bind a motif, GAAAG of the genes, c-myc (Kuo and Calame 2004; Shaffer et al. 2002), IFN-β (Kuo and Calame 2004), Pax-5 (Kuo and Calame 2004), Spi-B (Kuo and Calame 2004; Shaffer et al....
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...Annu Rev Biochem 72: 291-336 Chen H, Gilbert CA, Hudson JA, Bolick SC, Wright KL, Piskurich JF (2007) Positive regulatory domain Ibinding factor 1 mediates repression of the MHC class II transactivator (CIITA) type IV promoter....
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...…et al. 2002), Id3 (Kuo and Calame 2004; Shaffer et al. 2002), ifng (Cimmino et al. 2008), and tbx21 (Cimmino et al. 2008), a motif, GAAAT or GAAAG of CIITA (Chen et al. 2007; Kuo and Calame 2004; Shaffer et al. 2002), and a motif, GAAAA of NLRP12 (Lord et al. 2009) and bcl6 (Cimmino et al. 2008)....
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133 citations
"Alternative splicing of medaka bcl6..." refers background or result in this paper
...This is in accordance with that Prdm1 and Bcl6 repress each other in the mammals (Cimmino et al. 2008; Diehl et al. 2008; Miyauchi et al. 2010; Ochiai et al. 2008; Tunyaplin et al. 2004)....
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...In the immune system, Prdm1 is highly expressed in the Th2 (T helper 2) cells and is required for normal Th2 humoral responses in vivo by repression of Bcl6 and Tbx21 (T-box transcription factor 21) which are necessary for Th1 cells (Cimmino et al. 2008)....
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...2002), ifng (Cimmino et al. 2008), and tbx21 (Cimmino et al....
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...This core sequence had been proved as binding motif of Prdm1 in bcl6 (Cimmino et al. 2008) and NLRP12 (Lord et al. 2009) of mice....
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...This core sequence had been proved as binding motif of Prdm1 in bcl6 (Cimmino et al. 2008) and NLRP12 (Lord et al....
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121 citations
"Alternative splicing of medaka bcl6..." refers background in this paper
...Introduction Bcl6 (B-Cell Lymphoma 6) is a member of the POK (POZ and Krüppel) ⁄ZBTB (zing nger and BTB) protein family (Lee and Maeda 2012)....
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...Page 2/22 Introduction Bcl6 (B-Cell Lymphoma 6) is a member of the POK (POZ and Krüppel) ⁄ZBTB (zing nger and BTB) protein family (Lee and Maeda 2012)....
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"Alternative splicing of medaka bcl6..." refers background or result in this paper
...This is in accordance with that Prdm1 and Bcl6 repress each other in the mammals (Cimmino et al. 2008; Diehl et al. 2008; Miyauchi et al. 2010; Ochiai et al. 2008; Tunyaplin et al. 2004)....
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...Bcl6 directly inhibits prdm1 expression or binds to Bach2 (BTB domain and CNC homolog 2) to repress prdm1 and represses plasmocytic differentiation (Ochiai et al. 2008; Tunyaplin et al. 2004)....
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"Alternative splicing of medaka bcl6..." refers background in this paper
...In the mammals, Hobit functions in NK cells (van Gisbergen et al. 2012) and T cells (Vieira Braga et al. 2015)....
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...Human HOBIT was identi ed in NK cells and effector-type CD8 + T cells (Vieira Braga et al. 2015)....
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