The paper concentrates on the study of reflection and transmission characteristics of waves at the interface of a thermoelastic-diffusive solid half-space underlying an inviscid liquid. The analytic expressions for amplitude ratios, reflection and transmission coefficients, in terms of incident angles and material parameters have been obtained for quasi-longitudinal (qP) and quasi-transverse (qSV) wave incidence. The normal and grazing incidence cases have also been derived and discussed. The total reflection phenomenon has also been discussed. The energy law has been shown to be obeyed by the incidence, reflected and transmitted waves by deriving energy equation and its simulation. The numerical computations of reflection and transmission coefficients have been carried out for copper material half-space in contact with water at the interface by using MATLAB software. The computer simulated results have been presented graphically in order to bring out clear comparison of various situations.

Recently, we showed that monoclonal antibodies (mAbs) that are reactive with derivatives of polysialic acid containing de-N-acetylated neuraminic acid (Neu) residues are protective against N. meningitidis group B strains (Moe et al. 2005, Infect Immun 73:2123; Flitter et al., in preparation). In addition, we found that fully de-N-acetylated PSA (i.e. poly alpha 2,8 Neu) conjugated to tetanus toxoid (DeNAc) elicits IgM and IgG antibodies of all subclasses in mice that bind to group B strains, activate human complement deposition, are protective in an infant rat model of meningococcal bacteremia and are bactericidal against group C strains (Moe et al, in press). We show here that anti-DeNAc mAbs, DA1 and DA2 (both IgM), are reactive with polysaccharides containing Neu, bind to group B, C, W135 and Y but not X strains grown in chemically defined media (CDM). However, when the group X strain is grown in CDM supplemented with human plasma, DA2 binds. Also both mAbs mediate bactericidal activity against B, C, W135, and X strains with human complement. The esults suggests that N. meningitidis express and/or acquire zwitterionic de-N-acetyl sialic acid antigens that can be the target of protective antibodies.