Abstract: A molding process includes flowing a polymer melt into the cavity of a mold which includes a core pin. After the mold is filled and skin layers of solidified polymer have formed adjacent the mold wall and core pin wall, the core pin is spun transversely to the direction of polymer melt flow. The invention includes hollow articles of improved mechanical properties made by the process.

Abstract: An irradiated plastic article of reduced gas transmission has a coating of silicon oxide on a surface thereof. A method to reduce gas transmission through a plastic article includes depositing a coating of silicon oxide thereon and irradiating, either prior to or subsequent to depositing the silicon oxide.

Abstract: A blood collection assembly includes a tube, which may be evacuated, and an insert therein. The insert is descendably affixed to the tube wall and, after separating a blood sample taken in the tube into solid and liquid phases, descends during centrifugation and comes to rest at the solid-liquid interface on a projection from the tube bottom. An interior surface of the assembly may be modified to render it clot activating. The invention includes a method for preparing a blood sample for analysis using the assembly.

Abstract: A blood collection assembly includes an evacuated container having an open end with a puncturable stopper therein. A receptacle in the container contains an additive and has an open end covered by a puncturable, non-resealable material.In a method for preparing a blood sample for analysis, the stopper and receptacle covering are punctured by a cannula, the cannula is partially retracted into the receptacle so that blood drawn through the cannula contacts the additive and washes it directly into the container through a hole in the covering made by the cannula.

Abstract: An irradiated plastic article of reduced gas transmission has a coating of silicon oxide on a surface thereof. A method to reduce gas transmission through a plastic article includes depositing a coating of silicon oxide thereon and irradiating, either prior to or subsequent to depositing the silicon oxide.

Abstract: A molding process for syndiotactic polypropylene includes holding the melt at a process temperature of about 27.degree. to 77.degree. C. to achieve a cycle time of less than 150.degree. C. and a haze value for a 2 mm thick article of less than 38%.

Abstract: A self supporting gel includes a gelling agent and an electrolyte dissolved in a solvent. The gel is conducting and may be used in a battery.

Abstract: A blood collection assembly includes a container, optionally covered by a puncturable septum and evacuated. A clotting enhancer in the container activates both the intrinsic and extrinsic coagulation pathways. The invention includes a method to make the clotting enhancer.

Abstract: A plastic article having a sharp point is made of a polymer of high impact strength and high hardness. The article may be a lancet or a needle for skin puncture, suturing or sewing. A method for preparing the article includes shear thinning a melt of a polymer and introducing the shear thinned melt into a mold which includes a sharp point.

Abstract: A blood collection assembly includes a tube, which may be glass or plastic, and a plastic insert therein. The insert has been plasma-treated to change the surface chemistry and render it clot activating.

Abstract: A catheter tubing has a layer of a hydrophobic stiffening polymer encapsulated by a layer of hydrophilic thermoplastic base polymer. Preferred stiffening polymers are polyesterpolyether block copolymers. Preferred base polymers are thermoplastic polyetherurethanes. The encapsulated layer may be a stripe or an annular layer having base polymer layers laminated on both surfaces thereof.

Abstract: In a method to modify the chemistry of a portion of the surface of an article, the surface is placed adjacent an electrode in a plasma chamber, the distance to the wall of the chamber being at least five times the size of the electrode. A plasma of very high power density is generated in a discharge volume surrounding the electrode so that the surface area closest to the electrode receives a very intense plasma which diminishes with increasing distance from the discharge volume thus forming a chemical gradient on the article surface. The preferred article is a tube having one closed end, and the gradient may be formed from either the closed end or the open end. The gradient may be of decreasing glass-like character or decreasing plastic-like character.

Abstract: A blood collection assembly includes a container, optionally covered by a puncturable septum and evacuated. A clotting enhancer in the container activates both the intrinsic and extrinsic coagulation pathways.

Abstract: A lubricious polymeric composition which is stable toward sterilizing radiation includes a semicrystalline polyolefin of narrow molecular weight distribution having incorporated therein a liquid mobilizing additive, a radiation stabilizing amount of a hindered amine, a lubricating amount of an erucic acid derivative and a clarifying amount of a sorbitol derivative. The invention includes a sterilized article fabricated from the composition and a method to radiation sterilize the article.

Abstract: A non-yellowing, impact resistant high hard segment polyurethane made from a non-aromatic diisocyanate, a diol chain extender and an aminodiol chain extender may also contain up to five percent by weight of a macroglycol. A catalyst free method to prepare the polyurethane is a feature of the invention.

Abstract: A method for enzyme immunoassay for a ligand suspected to be present in a liquid sample includes signal amplification by use of at least two enzymes and a blocked modulator for one of the enzymes. Ligand present in the liquid binds to an antiligand and an enzyme-labeled tracer. The resulting bound fraction is separated and the enzyme in the tracer removes the blocking group from the blocked modulator. The modulator activates or inhibits a second enzyme which catalyzes the conversion of a substrate to a product. The presence or absence of the ligand in the liquid is indicated by a signal, such as a color change or a rate of color change, associated with the product. The invention includes a new class of enzyme inhibitors and blocked inhibitors and a kit of materials useful for performing the method of the invention.

Abstract: An evacuated blood collection assembly includes a plastic container having a plasma-treated inside wall surface and an open end covered by a puncturable septum. The inside wall surface may also be abraded to increase surface area. The invention included a method to make the assembly.

Abstract: An article having surfaces in sliding contact is lubricated at the interface with a multi component system. A first crosslinked basement lubricant is coated onto a surface, such as a syringe barrel. A second lubricant is coated over the crosslinked lubricant. The second surface, such as a syringe stopper is engaged with the first surface. A second aspect of the invention is a method for lubricating an article such as a syringe. A low viscosity prebasement lubricant is evenly coated onto the inside surface of the syringe barrel and then crosslinked by a plasma to a viscous liquid or substantially solid basement lubricant. A second surface lubricant is then applied over the basement lubricant.

Abstract: A lubricious polymeric composition which is stable toward sterilizing radiation includes a semicrystalline polyolefin of narrow molecular weight distribution having incorporated therein a liquid mobilizing additive, a radiation stabilizing amount of a hindered amine, a lubricating amount of an erucic acid derivative and a clarifying amount of a sorbitol derivative. The invention includes a sterilized article fabricated from the composition and a method to radiation sterilize the article.

Abstract: A shaped medical article of a polymeric substrate is extrusion coated with a composition which includes a bioactive agent dispersed in a matrix polymer. Preferred bioactive agents are temperature sensitive agents which undergo thermal decomposition at a temperature above the processing temperature of the matrix polymer. Preferred matrix polymers have a melting point of about 100.degree. C. or lower.