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Your search keyword '"Xu, C.P."' showing total 15 results
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15 results on '"Xu, C.P."'

6. Staphylococcus aureus-Fibronectin Interactions with and without Fibronectin-Binding Proteins and Their Role in Adhesion and Desorption

Author

Xu, C.P., Boks, N.P., de Vries, J., Kaper, H.J., Norde, W., Busscher, H.J., van der Mei, H.C., Xu, C.P., Boks, N.P., de Vries, J., Kaper, H.J., Norde, W., Busscher, H.J., and van der Mei, H.C.

Abstract

Adhesion and residence-time-dependent desorption of two Staphylococcus aureus strains with and without fibronectin (Fn) binding proteins (FnBPs) on Fn-coated glass were compared under flow conditions. To obtain a better understanding of the role of Fn-FnBP binding, the adsorption enthalpies of Fn with staphylococcal cell surfaces were determined using isothermal titration calorimetry (ITC). Interaction forces between staphylococci and Fn coatings were measured using atomic force microscopy (AFM). The strain with FnBPs adhered faster and initially stronger to an Fn coating than the strain without FnBPs, and its Fn adsorption enthalpies were higher. The initial desorption was high for both strains but decreased substantially within 2 s. These time scales of staphylococcal bond ageing were confirmed by AFM adhesion force measurement. After exposure of either Fn coating or staphylococcal cell surfaces to bovine serum albumin (BSA), the adhesion of both strains to Fn coatings was reduced, suggesting that BSA suppresses not only nonspecific but also specific Fn-FnBP interactions. Adhesion forces and adsorption enthalpies were only slightly affected by BSA adsorption. This implies that under the mild contact conditions of convective diffusion in a flow chamber, adsorbed BSA prevents specific interactions but does allow forced Fn-FnBP binding during AFM or stirring in ITC. The bond strength energies calculated from retraction force-distance curves from AFM were orders of magnitude higher than those calculated from desorption data, confirming that a penetrating Fn-coated AFM tip probes multiple adhesins in the outermost cell surface that remain hidden during mild landing of an organism on an Fn-coated substratum, like that during convective diffusional flow.

Published
2008

14. Microstructural evolution of the pyrochlore compound Er2Ti2O7 induced by light ion irradiations

Author

Li, Y.H., Wang, Y.Q., Xu, C.P., Valdez, J.A., Tang, M., and Sickafus, K.E.

Subjects
*MICROSTRUCTURE, *PYROCHLORE, *TITANIUM oxides, *ION bombardment, *X-ray diffraction, *CRYSTAL lattices, *AMORPHOUS substances
Abstract

Abstract: In this report, we present results of an irradiation damage study on a pyrochlore compound, Er2Ti2O7. Polycrystalline Er2Ti2O7 was irradiated with 400keV Ne2+ ions at cryogenic temperature (∼77K) to fluences ranging from 2×1018 to 2×1019 ions/m2. Irradiation-induced microstructural evolution was examined using grazing incidence X-ray diffraction (GIXRD) at angles of γ =0.25° and 3°. It was found that the irradiated Er2Ti2O7 undergoes significant lattice swelling before succumbing to a radiation-induced partial amorphization transformation. Both of the extent of the lattice swelling and the lattice disorder of the Er2Ti2O7 increase with increasing Ne ion fluence prior to partial amorphization. We present here a detailed discussion regarding the nature of the defects responsible for the observed lattice swelling and disorder in Er2Ti2O7. [Copyright &y& Elsevier]

Published
2012
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15. Light ion irradiation effects on stuffed Lu2(Ti2− x Lu x )O7− x /2 (x =0, 0.4 and 0.67) structures

Author

Li, Y.H., Wang, Y.Q., Zhou, M., Xu, C.P., Valdez, J.A., and Sickafus, K.E.

Subjects
*LUTETIUM, *X-ray diffraction, *FLUORITE, *ANIONS, *MEASUREMENT, *STOICHIOMETRY, *METAL ions, *IRRADIATION
Abstract

Abstract: We have recently synthesized “stuffed” (i.e., excess Lu) Lu2(Ti2− x Lu x )O7− x /2 (x =0, 0.4 and 0.67) compounds using conventional ceramic processing. X-ray diffraction measurements indicate that stuffing more Lu3+ cations into the oxide structure leads eventually to an order-to-disorder (O–D) transition, from an ordered pyrochlore to a disordered fluorite crystal structure. At the maximum deviation in stoichiometry (x =0.67), the Lu3+ and Ti4+ ions become completely randomized on the cation sublattices, and the oxygen “vacancies” are randomized on the anion sublattice. Samples were irradiated with 400keV Ne2+ ions to fluences ranging from 1×1015 to 1×1016 ions/cm2 at cryogenic temperatures (∼77K). Ion irradiation effects in these samples were examined by using grazing incident X-ray diffraction. The results show that the ion irradiation tolerance increases with disordering extent in the non-stoichiometric Lu2(Ti2− x Lu x )O7− x /2. [Copyright &y& Elsevier]

Published
2011
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