Aims To evaluate the in vitro and in vivo effectiveness of egg yolk immunoglobulin (IgY) against periodontal disease‐causing Fusobacterium nucleatum. Methods and Results Four White Leghorn hens (120 days old) were immunized with whole Fus. nucleatum cells killed with 1% formaldehyde using three injections provided at 2‐week intervals. IgY was produced from egg yolks obtained from these immunized hens using water dilution, two‐step salt precipitation and ultrafiltration. This IgY was shown to have a purity of 86·8% based on its optical intensity in the stained SDS‐PAGE bands. An enzyme‐linked immunosorbent assay indicated a high specificity for the IgY against Fus. nucleatum with a maximum antibody titre of 80 000. The IgY had only weak cross‐reactivity with Porphyromonas gingivalis, Prevotella intermedia and Solobacterium moorei. Growth and biofilm formation by Fus. nucleatum were inhibited by IgY at concentrations of 10 and 20 mg ml−1. Immunofluorescence and immunoelectron microscope assays revealed a high binding ability of specific IgY, which may explain the in vitro effectiveness of IgY. In an in vivo study, IgY treatment resulted in a marked decrease in alveolar bone loss after Fus. nucleatum infection in a mouse model confirming the effectiveness of IgY against periodontal disease‐causing Fus. nucleatum. Conclusions IgY effectively inhibited growth and biofilm formation by Fus. nucleatum and prevented the progression of periodontal disease by decreasing alveolar bone loss. Significance and Impact of the Study Specific IgY may have potential for the treatment of periodontal disease.

We examine three overlapping problems in the application of five-dimensional ͑5D͒ manifolds to physics. First, we linearize the 5D theory along the lines of the four-dimensional ͑4D͒ theory, using the harmonic gauge condition. The resulting wave equations have sources, and can in principle describe gravitons and scalar particles with finite masses, but the natural choice of gauge parameters makes both massless. Second, we generalize the 5D metric by including separate conformal factors on its 4D and extra parts. Then the 5D harmonic gauge gives back the 4D harmonic gauge of gravitational waves and the Lorentz gauge of electromagnetic waves, but both particles are massless. Third, we again take a conformally rescaled metric, but rewrite the field equations in a novel manner. This allows us to interpret the finite masses of ordinary particles in terms of the wavelengths associated with 4D spaces embedded in a 5D space.

AZ91HP magnesium alloy was melted by CO 2 laser. Compared with as-received Mg alloy, the grain of the melted layer was refined significantly and the content of Al was increased. The corrosion resistance of the melted layer was improved because of the grain refinement, the redistribution of b-Mg 17 Al 12 and the increasing of the Al content. As compared to the non-overlapping zone, the overlapping zone of the melted layer was liable to be corroded.

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