ULTRASONIC PROPERTIES OF A SUPERIONIC GLASS : B2O3, 0.5 Li2O, 0.7 LiCl

We measured the attenuation and the phase velocity variations of longitudinal ultrasonic waves in a superionic glass of composition : B2O3, 0.5 Li2O, 0.7 LiCl. The experimental curves show at least three different mechanisms of sound attenuation. Comparison with the result for a less conductive compound (B2O3, 0.5 Li2O) is done. Two of the mechanisms are attributed to the glassy nature of the compound. One is believed to be due to the superionic properties of the material

Acousto-Optic Diffraction by Shear Horizontal Surface Acoustic Waves in 36° Rotated Y-Cut X-Propagation Lithium Tantalate

We have investigated the acousto-optic diffraction by shear horizontal surface acoustic waves in 36° rotated Y-cut X-propagation lithium tantalate ($LiTaO_3$) crystals. The measurements were performed at the optical wavelength 633 nm of He-Ne laser and acoustic wavelengths of 50-60 μ m. The anisotropic diffraction with the light polarization rotation in the transmission mode was observed. The measured and calculated values of the light incidence angle corresponding to the strongest diffraction differed significantly. A narrow strip of a thin metal film deposited on the crystal surface drastically affected the light diffraction. We attribute these effects to the conversion processes between the shear horizontal leaky surface acoustic wave and shear horizontal surface skimming bulk wave

Acoustoelectric investigation of V2O5·nH2O thin film transition from wet gel to xerogel

The strong acoustoelectric interaction in thin films of vanadium pentoxide hydrate (V2O5·nH2O) fabricated by the sol–gel method on the YZ LiNbO3 substrate was investigated using the surface acoustic wave (SAW) technique. Significant variations of the SAW amplitude and phase during a few first hours after the structure fabrication were attributed to the changes in the film conductivity linked to the water loss in the V2O5·nH2O films during the transition process from wet gel to xerogel. The SAW measurements revealed that the conductivity of vanadium pentoxide hydrate films linearly increased with time as the water amount, n, in V2O5·nH2O decreased according to a logarithmic law from 8 to 6.3. The estimated interlayer distance between V–O layers in the hydrate structure was 23 Å–21 ÅFizinių ir technologijos mokslų centro Puslaidininkių fizikos institutasVilniaus universitetasVytauto Didžiojo universitetasŠvietimo akademij

Investigation of a GaN-Based SAW Oscillator with respect to UV Illumination and Temperature

Oscillation frequency of a GaN-based surface acoustic wave delay-line oscillator is investigated in the temperature range from -20°C to +38°C, with and without UV illumination. The results imply that such an oscillator may be used for temperature sensing with the resolution of up to 1 mK. On the other hand, as the frequency downshift due to UV illumination does not exhibit a significant dependence on temperature, it may be expected that such a system, when used as a UV sensor, would not require applying a correction for temperature

Antibodies to calnexin and mutated calreticulin are common in human sera /

Purpose of the study: Calreticulin is an endoplasmic reticulum chaperone protein, which is involved in protein folding and in peptide loading of major histocompatibility complex class I molecules together with its homolog calnexin. Mutated calreticulin is associated with a group of hemopoietic disorders, especially myeloproliferative neoplasms. Currently only the cellular immune response to mutated calreticulin has been described, although preliminary findings have indicated that antibodies to mutated calreticulin are not specific for myeloproliferative disorders. These findings have prompted us to characterize the humoral immune response to mutated calreticulin and its chaperone homologue calnexin. Patients and methods: We analyzed sera from myeloproliferative neoplasm patients, healthy donors and relapsing-remitting multiple sclerosis patients for the occurrence of autoantibodies to wild type and mutated calreticulin forms and to calnexin by enzyme-linked immunosorbent assay. Results: Antibodies to mutated calreticulin and calnexin were present at similar levels in serum samples of myeloproliferative neoplasm and multiple sclerosis patients as well as healthy donors. Moreover, a high correlation between antibodies to mutated calreticulin and calnexin was seen for all patient and control groups. Epitope binding studies indicated that cross-reactive antibodies bound to a three-dimensional epitope encompassing a short linear sequence in the C-terminal of mutated calreticulin and calnexin. Conclusion: Collectively, these findings indicate that calreticulin mutations may be common and not necessarily lead to onset of myeloproliferative neoplasm, possibly due to elimination of cells with mutations. This, in turn, may suggest that additional molecular changes may be required for development of myeloproliferative neoplasm