The electrode Pt-loading has an effect on the number of active sites and the thickness of catalyst layer,which has huge influence on the mass transfer and water management during dynamic process in PEMFCs. In this stu...The electrode Pt-loading has an effect on the number of active sites and the thickness of catalyst layer,which has huge influence on the mass transfer and water management during dynamic process in PEMFCs. In this study, membrane electrode assemblies with different Pt-loadings were prepared, and PEMFCs were assembled using those membrane electrode assemblies with traditional solid plate and water transport plate as cathode flow-field plates, respectively. The performance and electrochemical surface area of cells were characterized to evaluate the membrane electrode assemblies degradation after rapid currentvariation cycles. Scanning electron microscope and transmission electron microscope were used to investigate the decay of catalyst layers and Pt/C catalyst. With the increase of Pt-loading, the performance degradation of membrane electrode assemblies will be mitigated. But higher Pt-loading means thicker catalyst layer, which leads to a longer pathway of mass transfer, and it may result in carbon material corrosion in membrane electrode assemblies. The decay of Pt/C catalyst in cathode is mainly caused by the corrosion of carbon support, and the degradation of anode Pt/C catalyst is a consequence of migration and aggregation of Pt particles. And using water transport plate is beneficial to alleviating the age of cathode Pt/C catalyst.展开更多
In liver transplantation, liver graft ischemia-reperfusion injury occurs mainly due to cold preservation and warm reperfusion. In this research, we study the affection of plasma protein of the donor on liver graft dur...In liver transplantation, liver graft ischemia-reperfusion injury occurs mainly due to cold preservation and warm reperfusion. In this research, we study the affection of plasma protein of the donor on liver graft during cold preservation and warm reperfusion. In this study, 34 liver transplantations were performed from 2007 to 2010, and the clinical data were collected retrospectively from the Dongfang Hospital database. 34 specimens were harvested from 34 liver grafts when graft trimming as Group A and 34 specimens harvested from the same 34 liver grafts during liver transplantation surgery but before abdominal closure as B group. All liver tissue specimens were fixed with 40 g/L neutral formalin, embedded in paraffin. Light microscopy, transmission electron microscopy, Periodic Acid-Schiff (PAS) stain and immunohistochemical stain of IgG, IgM, IgA, C3d, C4d, Fib, C1q, and CD61 were used. In this study, we found that eosinophilic bodies emerged in liver lobes during liver transplantation which had not been reported previously in the literature. 1) Protein globules were found exclusively in liver graft specimens. The globules were round or oval with sharp edges, measured approximately 1.59 to 9.41 μm in diameter, and were scattered in the liver sinusoids or space of Disse or hepatocyte cytoplasm, were stained with IgG, IgM, IgA, Fib, C3d by immunohistochemical staining;2) There was no statistical significant difference of protein globules number between A group and B group (P > 0.05);3) IRI score of B group was not correlated with protein globules number (P > 0.05). Protein globules contain plasma composition, and may form during cold preservation.展开更多
The Streptomyces phage φC31 integrase can efficiently target attB-bearing transgenes to endogenous pseudo attP sites within mammalian genomes. To better understand the activity of φC31 integrase in the bovine genome...The Streptomyces phage φC31 integrase can efficiently target attB-bearing transgenes to endogenous pseudo attP sites within mammalian genomes. To better understand the activity of φC31 integrase in the bovine genome, DNA sequences of 44 integration events were analyzed, and 32 pseudo attP sites were identified. The majority of these sites share a sequence motif that contains inverted repeats and has similarities to wild-type attP site. Genomic DNA flanking these sites typically contained repetitive sequence elements, such as short and long interspersed repetitive elements. These sequence features indicate that DNA sequence recognition plays an important role in guiding φC31-mediated site-specific integration. In addition, BF27 integration hotspot sites were identified in the bovine genome, which accounted for 13.6% of all isolated integration events and mapped to an intron of the deleted in liver cancer 1 （DLC1） gene. Also we found that the pseudo attP sites in the bovine genome had other features in common with those in the human genome. This study represents the first time that the sequence features of pseudo attP sites specific integrase system has great potential for applied modifications in the bovine genome were analyzed. We conclude that this site- of the bovine genome.展开更多
基金supported by the National Major Research Project(2016YFB0101208)the National Natural Science Foundation of China(21576257)+1 种基金the Natural Science Foundation-Liaoning United Fund(U1508202)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB06050303)~~
基金financially supported by the National Key Research and Development Program of China (Grant no.2016YFB0101208)NSFC-Liaoning Joint Funding (Grant no. U1508202)the National Natural Science Foundations of China (Grant no. 61433013 and 91434131)
文摘The electrode Pt-loading has an effect on the number of active sites and the thickness of catalyst layer,which has huge influence on the mass transfer and water management during dynamic process in PEMFCs. In this study, membrane electrode assemblies with different Pt-loadings were prepared, and PEMFCs were assembled using those membrane electrode assemblies with traditional solid plate and water transport plate as cathode flow-field plates, respectively. The performance and electrochemical surface area of cells were characterized to evaluate the membrane electrode assemblies degradation after rapid currentvariation cycles. Scanning electron microscope and transmission electron microscope were used to investigate the decay of catalyst layers and Pt/C catalyst. With the increase of Pt-loading, the performance degradation of membrane electrode assemblies will be mitigated. But higher Pt-loading means thicker catalyst layer, which leads to a longer pathway of mass transfer, and it may result in carbon material corrosion in membrane electrode assemblies. The decay of Pt/C catalyst in cathode is mainly caused by the corrosion of carbon support, and the degradation of anode Pt/C catalyst is a consequence of migration and aggregation of Pt particles. And using water transport plate is beneficial to alleviating the age of cathode Pt/C catalyst.
文摘In liver transplantation, liver graft ischemia-reperfusion injury occurs mainly due to cold preservation and warm reperfusion. In this research, we study the affection of plasma protein of the donor on liver graft during cold preservation and warm reperfusion. In this study, 34 liver transplantations were performed from 2007 to 2010, and the clinical data were collected retrospectively from the Dongfang Hospital database. 34 specimens were harvested from 34 liver grafts when graft trimming as Group A and 34 specimens harvested from the same 34 liver grafts during liver transplantation surgery but before abdominal closure as B group. All liver tissue specimens were fixed with 40 g/L neutral formalin, embedded in paraffin. Light microscopy, transmission electron microscopy, Periodic Acid-Schiff (PAS) stain and immunohistochemical stain of IgG, IgM, IgA, C3d, C4d, Fib, C1q, and CD61 were used. In this study, we found that eosinophilic bodies emerged in liver lobes during liver transplantation which had not been reported previously in the literature. 1) Protein globules were found exclusively in liver graft specimens. The globules were round or oval with sharp edges, measured approximately 1.59 to 9.41 μm in diameter, and were scattered in the liver sinusoids or space of Disse or hepatocyte cytoplasm, were stained with IgG, IgM, IgA, Fib, C3d by immunohistochemical staining;2) There was no statistical significant difference of protein globules number between A group and B group (P > 0.05);3) IRI score of B group was not correlated with protein globules number (P > 0.05). Protein globules contain plasma composition, and may form during cold preservation.
基金supported by the grants from the National Science and Technology Major Project of China(Nos. 2009ZX08010-018B and 2011ZX08007-004)State & Shanghai Leading Academic Discipline(B204)
文摘The Streptomyces phage φC31 integrase can efficiently target attB-bearing transgenes to endogenous pseudo attP sites within mammalian genomes. To better understand the activity of φC31 integrase in the bovine genome, DNA sequences of 44 integration events were analyzed, and 32 pseudo attP sites were identified. The majority of these sites share a sequence motif that contains inverted repeats and has similarities to wild-type attP site. Genomic DNA flanking these sites typically contained repetitive sequence elements, such as short and long interspersed repetitive elements. These sequence features indicate that DNA sequence recognition plays an important role in guiding φC31-mediated site-specific integration. In addition, BF27 integration hotspot sites were identified in the bovine genome, which accounted for 13.6% of all isolated integration events and mapped to an intron of the deleted in liver cancer 1 （DLC1） gene. Also we found that the pseudo attP sites in the bovine genome had other features in common with those in the human genome. This study represents the first time that the sequence features of pseudo attP sites specific integrase system has great potential for applied modifications in the bovine genome were analyzed. We conclude that this site- of the bovine genome.
