Intermediate Contact Research Articles

Oral mucosa usage tests

Various methods to evaluate the biologic reactions of the gingiva and the oral mucosa to dental materials are discussed. Examples and results are given of tests in subgingival cavity preparations, tests in buccal pouches, and tests in contact to the palatal mucosa for short, intermediate, and prolonged contact periods between the material and the mucosa. Proved testing appliances are described. The results, compared with those of toxicity screening tests, indicate the need for an alternate applied test.

Gas absorption into turbulent liquids at intermediate contact times

Gas absorption into turbulent liquids at intermediate contact times

Intercellular contacts at the epithelial-mesenchymal interface during the prenatal development of the rat submandibular gland

During the investigation of the embryogenesis of the rat submandibular gland (SMG), direct epithelial-mesenchymal and epithelial-nerve contacts were observed by light and electron microsopy. These contacts were seen at the epithelial-mesenchymal interface of the end buds of the initial four to twelve branches of the glandular rudiment during the period of rapid branching and budding of the analage. The epithelial-mesenchymal contacts were made by either mesenchymal or epithelial cell extensions which penetrated small gaps in the basal lamina to contact an apposing cell. The epithelial-mesenchymal contact zones showed several morphologic variations, but no septate or gap junctions were seen. The epithelial-nerve contacts were primarily of the intermediate contact zone variety although some tight-type contacts were seen. They were not typical synaptic junctions. The fine structure and importance of these unusual contact zones in the prenatal differentiation of the submandibular gland rudiment are discussed.

Creep bowing of a fuel element against a continuous restraint

The behaviour of fuel elements with initial bows of various forms and ends either held in a pin jointed manner in the centre of the channel or allowed to tilt across it is investigated for up to 100 doubling times after intermediate contact occurs and the displacements and forces at points of contact are evaluated. The maximum horizontal force up to 100 doubling times was found to be about sixteen times the vertical load times the ratio of the effective clearance to the length of the element, for a variety of different forms of initial bow and end condition. Small deviations in the shape of an initial bow in general had no significant effects on the shape after an appreciable number of doubling times.

Superconducting Connections to Films

A method for making superconducting connections to thin films of evaporated metal deposited on wires has been found useful at this laboratory. Compressed lead powder of the smallest commercial particle size is used as an intermediate contact between the film and external circuitry.