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Abstract: Erasable electrical conductive domain walls in an insulating ferroelectric matrix provide novel functionalities for applications in logic and memory devices. The crux of such success requires sufficiently high wall currents to drive high‐speed and high‐power nanodevices. This work provides an appealing strategy to increase the current by two orders of magnitude through the careful selection of current flowing paths along the charged walls. The dense walls come into form through the hierarchical evolution of the 71°, 109°, and 180° domains of epitaxial BiFeO3 films in a planar‐geometry ferroelectric resistance‐switching memory cell. The engineered films grown on SrTiO3 and GdScO3 substrates allow the observation of detailed local configurations and the evolution of the different domain types using vector piezo‐force microscopy. The higher local electrical conductivity near the charged domain walls is identified by conductive atomic‐force microscopy. It is shown that 180° domain reversal proceeds by three‐step 71° rotations of the pristine domains. Surprisingly, a maximum current of ≈300 nA is observed for current paths along charge‐uncompensated head‐to‐head hierarchical domain walls connecting the two electrodes on the film surface. Furthermore, the achievable current level can be conveniently controlled by varying the relative directions of the initial polarization and the applied field. [ABSTRACT FROM AUTHOR]

Aim: To investigate the promoter activity of BCMA gene 5'-flanking regionfor the study the regulation mechanism of BCMA expression., Methods: Luciferase reporter plasmids containing 5'-flanking region of BCMA gene and serial deletions of the fragment were constructed. The luciferase expression was observed after these reporters were transfected into J558L, 293T and Hela cells., Results: The highest transcriptional activation was expressed in pGL3-B157 reporter, followed by pGL3-B607, pGL3-B359, pGL3-B93, and pGL3-B820 in sequence. The highest transcriptional activation was in J558L cell., Conclusion: The 5'-flanking sequence from -820 to +145 bp of BCMA is of promoter activity. Serial deletion analysis of the promoter region of BCMA gene suggests the sequence from -93 to +145 could be a core promoter region.

Aim: To study the role of adaptor protein Bam32 in B cell antigen receptor (BCR) signaling cascades., Methods: Using full length Bam32 as bait, yeast two-hybrid technique was used to screen the protein that could interact with Bam32. The interaction was further confirmed by co-transfection of 293T cells and coimmunoprecipitation., Results: Protein tyrosine kinase Lyn was one of the strong positive clones identified by the yeast two-hybrid screening. This interaction was further confirmed in 293T cells by co-transfection and coimmunoprecipitation. By using specific anti-phosphotyrosine antibody, it was found that Bam32 could be phosphorylated by Lyn., Conclusion: The interaction of Bam32 with Lyn leads to Bam32 phosphorylation, which might play an important role in activating downstream signaling molecules.