Abstract: Clinically useful diagnostic devices are prepared from commercially available metal sheet stock by a sequence of steps. The metal is one of a type on the surface of which a tenacious oxide layer can be produced. Steps in the preparation include roughening surface area of the bulk metal with pits on a fine scale to render that surface area of the metal non-specularly reflecting, chemically etching the surface area to produce some first preselected measure of reflectivity, anodizing the surface area to produce a dull, non-specularly reflecting oxide surface having a second preselected degree of reflectivity and applying a layer of protein over this dull surface area. The preferred metal is titanium and the reflectivity of the modified surface area is selected dependent on the immunological reaction being detected.

Abstract: Hydrogen sulfide is removed from a mixture of gases including carbon dioxide by passing the mixture over an assembly comprising a pair of immobilized liquid membranes of carbonate/bicarbonate solution separated by a gas permeable barrier of hydrophobic microporous material. Because hydrogen sulfide transport through the membranes is diffusion limited while carbon dioxide transport therethrough is reaction rate limited, the assembly exhibits reduced permeability to carbon dioxide and essentially unchanged high permeability to hydrogen sulfide compared to a single immobilized liquid membrane of thickness equal to total thickness of the membranes in the assembly. Hydrogen sulfide thus passes through the assembly more selectively than carbon dioxide.

Abstract: A combined diagnostic device/housing combination is described. In its preferred application it is adapted to the detection of biological particles by the utilization of the phenomenon by which such biological particles interact specifically either immunologically or non-immunologically. The combination comprises a tube closed at one end, means (i.e., a cap) removably engageable with the opposite end of the tube to achieve sealing thereof such as to preclude the entry of microorganisms, a rod-like member affixed at one end thereof to the sealing means so as to project therefrom and a functional test device affixed to the free end of the rod-like member. When assembled, the rod-like member and test device are disposed within the tube and the tube is sealed ready for storage, shipping and/or use. Preferably, when the test device is for testing for specific biological particle interaction, the complete structure is made of glass and/or metal.

Abstract: A method and apparatus are described for reducing or removing the background noise caused by thoron gas (.sup.220 Rn) in uranium exploration conducted by the detection of radon gas (.sup.222 Rn) emanating from the ground. This is accomplished by the use of a number of alpha particle detectors, each of which is disposed in a protective enclosure. A permselective membrane, which permits, but selectively retards, the passage therethrough of gases is disposed in the path to be traversed before such gases can reach the alpha particle detector. The retarding influence of the membrane should be sufficient to make the concentration of thoron inside the enclosure small relative to the concentration of thoron outside the enclosure. The influence of the membrane on radon should be negligible, i.e. the randon concentration inside and outside the enclosure should be substantially equal.