Al diffusion in ZnO Nanowalls Investigated by Atom Probe Tomography

Synthesis of ZnO nanowall structures using Ni catalyst was studied. ZnO nanowalls were grown by vapour-liquid-solid method. Ni as being a catalyst in the formation of ZnO nanowalls provided nucleation sites for the nucleation and the growth of ZnO nanowalls. Even though the sapphire system with ZnO has the high stability, the reactions between ZnO nanowalls and the sapphire substrate formed a 10-nm-thick interlayer during ZnO nanowall growth. Moreover, during the growth of the ZnO nanowalls, diffusion of Ni and Al was not expected as the Ni-Sapphire system is known to be non-reactive. Atom-probe tomography revealed that Al and Ni diffused into the NiO interface and sapphire substrate. Al diffused along the interface generated by the growth of ZnO nanowall, but Ni diffused into the interlayer between ZnO and sapphire.X1133sciescopuskc

Accumulation of CD4+CD7− T cells in inflammatory skin lesions: evidence for preferential adhesion to vascular endothelial cells

The CD7− subset of CD4+ memory T cells reflects a stable differentiation state of post-thymic helper T cells and represents a small subpopulation in circulating blood. We here demonstrate that CD7− T cells preferentially accumulate in skin lesions under chronic inflammatory conditions irrespective of the particular disease. As adhesion to vascular endothelial cells (EC) is required for migration of circulating lymphocytes into tissues, we analysed the adherence of purified subsets of CD4+ memory T cells to endothelial cells in vitro. Compared with CD4+CD7+ T cells, cells of the CD4+CD7− subset preferentially adhere to EC, which is moreover increased after prestimulation of EC with tumour necrosis factor-alpha (TNF-α). Stimulated EC increase expression of intercellular adhesion molecule-1 (CD54) and E-selectin (CD62E), the ligand of which, cutaneous lymphocyte-related antigen (CLA), is highly expressed in CD4+CD7− T cells but not in CD4+CD7+ T cells. LFA-1 is expressed in a bimodal distribution on CD4+CD7− T cells in contrast to CD4+CD7+ cells, whereas VLA-1, VLA-3, and VLA-5 are nearly similarly expressed in both T cell subsets. Our results imply that the preferred adherence of CD4+CD7− memory T cells to vascular EC, which is increased after long-term EC stimulation with TNF-α, is likely to facilitate their accumulation in various inflammatory skin lesions