Salivary Mucocele in a Laboratory Beagle

The histologic characteristics of a salivary mucocele in a beagle used in a toxicity study are described in this report. A pale yellowish cyst under the mandibular skin containing frothy mucus was observed at necropsy. Microscopically, numerous villous projections arose from the internal surface of the cyst and were lined by stratified epithelial-like macrophages, which were immunopositive for macrophage scavenger receptor A. A ruptured sublingual interlobar duct connected to the lumen was observed near the cyst. Luminal amorphous material showed a positive reaction with Alcian blue and periodic acid-Schiff staining as did mucin in the sublingual gland. Ultrastructurally, the epithelial-like macrophages had numerous vacuoles containing electron-lucent material, which was presumed to be lysosomal in origin, and had pseudopods on their cell surfaces interdigitating with those on the adjacent cells. This case report helps to understand the diversity of the background findings in beagles used in toxicity studies

High Field Properties of Nb_3Ge and NbN Films (Low-T_c Superconducting Materials Research)

Sputtered and CVD-prepared films of A15-type Nb_3Ge and sputtered films of B1-type NbN have been studied on their high field properties. Further, strain effects of critical current density J_c have been investigated on NbN. The J_c of sputtered Nb_3Ge films exceeds 1x10^5 A/cm^2 at fields up to 20 T. In CVD-prepared films, the J_c is somewhat lower in fields higher than 20 T and is highly affected by their deposition temperature. The upper critical field B_ of two kinds of films is roughly proportional to their transition temperature T_c. NbN films have anisotropy in B_, which yields strong anisotropy in J_c with respect to the field orientation. The values of J_c are higher in the perpendicular field to a film plane and reach 1x10^5 A/cm^2 at 21 T. The B_ increases with ρ_n. Little change in J_c has been observed under strains above 1 % at 9 T for NbN films on Hastelloy B tape