Abstract: An artificial pancreas system which minimizes the volume of the artificial pancreas by not encapsulating each islet is taught wherein the islets are separated and held within a polymeric matrix which is soluble in an aqueous solution below body temperature but insoluble in aqueous solutions at or above body temperature. The polymer-islet mixture is contained in a pouch having access means such as entry and exit ports. The solubility makes it possible to replace the contents of the pouch by solubilizing the matrix simply by lowering the temperature below the LCST. The pouch is constructed of a biocompatible material permeable to insulin and other substances of similar or lesser molecular weight but is impermeable to cellular and humoral components of the body immune system. The islet-polymer matrix can be functionalized to stimulate insulin secretion from the islets using insulinotropic agents such as sulfonylurea.

Abstract: A three-dimensional electrode device is disclosed. The device is useful as a neuron interface or as a cortical implant. A plurality of spire-shaped electrodes, formed of semiconductor material, are associated with a rigid base. The electrodes are electrically isolated from each other at the base. Multiplexing circuitry allows the electrodes to be addressed individually.

Abstract: Methods and compositions for use in optically recording information. The present invention includes incorporating solute molecules within an extremely viscous medium. The solute molecules may be chemically bound within the medium or they may be held physically in place. In either case actual rotation of the solute molecules is prevented. The solute molecules are chosen such that they are capable of generalized pseudorotation. That is, the solute molecules or chromophores attached to a polymer chain may be converted from a first form to a second form which differs in orientation without a net chemical transformation into another chemical species and in the absence of actual rotation. In addition, the various forms of the solute molecules can be produced by passing selectively polarized light through the medium. The form of the solute molecules can then be "read" by passing light through the medium and detecting its characteristics as it exits the medium.

Abstract: The present invention is directed to prosthesis and methods for promoting nerve regeneration. The proximal and distal ends of a severed nerve are brought into close proximity and are enclosed by a tubular prosthesis. In one preferred embodiment, a epineurial or endoneurial monosuture is used to hold the nerve ends in close proximity. A tight seal is formed between the prosthesis and the injured nerve so as to isolate the injured nerve within the prosthesis from the rest of the body of the host. Additionally, in one preferred embodiment, nerve grafts may be incorporated into the prosthesis and nerve regeneration promoting substances may be incorporated within the nerve graft to further enhance nerve regeneration.

Abstract: Methods and apparatus for administering known quantities of medicaments by iontophoresis while avoiding burns caused by extremes in the pH of the medicament medium during passage of an electric current are disclosed. It has been found that, as iontophoresis progresses in conventional iontophoresis systems, the electrolysis of water occurs to produce hydrogen or hydroxyl ions at the interface of the electrode and medicament medium. Since these ions are highly mobile, they are transported directly into the skin of patient in preference to the larger medicament ions. Thus, extreme changes in pH are experienced which result in burns due to the acidification or alkalinization of the medicament medium and passage of electric current through the skin. The present invention also avoids the production of other competing ions by employing a reactive electrode.

Abstract: An electronic hearing device for stimulating the auditory nerve by way of implanted electrodes wherein sound signals are converted to electrical signals which are divided into separate channels according to their frequencies. The signals of each channel are amplified and applied to the electrodes. The relative amplifications of each channel, after taking into account a threshold amplification, have a ratio of 6 to 7 dB/octave from the channel having the lowest center frequency to the channel having the highest center frequency.

Abstract: Polymers, the surfaces of which have been modified, are disclosed. The polymer surface is modified by embedding therein a second polymer. The modified polymer substantially retains its bulk properties while also possessing, at its surface, properties of the second polymer.

Abstract: A nondestructive system and method for the determination of the presence and extent of hydrogen embrittlement in metals, alloys, and other crystalline structures subject thereto. Positron annihilation characteristics of the positron-electron annihilation within the tested material provide unique energy distribution curves for each type of material tested at each respective stage of hydrogen embrittlement. Gamma radiation resulting from such annihilation events is detected and statistically summarized by appropriate instrumentation to reveal the variations of electron activity within the tested material caused by hydrogen embrittlement therein. Such data from controlled tests provides a direct indication of the relative stages of hydrogen embrittlement in the form of unique energy distribution curves which may be utilized as calibration curves for future comparison with field tests to give on-site indication of progressive stages of hydrogen embrittlement.

Abstract: A chemical sensitive field-effect transistor transducer capable of selectively detecting and measuring chemical properties of substances to which the transducer is exposed. The transducer includes a semiconductor substrate material having a certain doping polarity, a pair of spaced apart diffusion regions located at the surface of the substrate material and having a doping polarity opposite that of the substrate material, electrical insulator material overlying the diffusion regions and the surface of the substrate material lying between the diffusion regions, and a chemical selective system overlying the insulator material. The chemical selective system is adapted to interact with certain substances and thereby modulate an electric field produced in the substrate material between the diffusion regions. This modulation is dependent upon the chemical properties of the substances and provides a measure of those chemical properties.

Abstract: A method and composition of matter for reducing warts with an active compound including phosphonoacetic acid, methylphosphonic acid and/or at least one of the physiologically acceptable sodium, potassium and calcium derivatives thereof and, if desired, a tissue penetrating and/or tissue removing agent. The method includes contacting a wart with the composition of this invention until the wart has been suitably reduced.

Abstract: An apparatus for determining rotation of an area including optical apparatus for optically circumscribing the area and to guide laser radiation counter-directionally around the circumscribed area. Differences that develop between the clockwise and counterclockwise laser radiation as a function of the rotation of the area are detected to determine the rotation of the area. The optical apparatus includes an optical fiber waveguide which may function as a laser cavity or a ring inferometer path. The ring inferometer may also be provided by at least three reflective surfaces.

Abstract: A method for preparing a dense and strong polycrystalline .beta."-alumina-containing ceramic body exhibiting an elecrical resistivity at 300.degree. C of 5 ohm-cm or lower, and a controlled and uniform grain size under 50 micrometers, comprising:A. preparing fully converted .beta."-alumina seeds;B. mechanically mixing in the above-mentioned .beta."-alumina seeds with a matrix powder of a composition consistent with the formation of .beta."-alumina upon sintering; andC. sintering at about 1600.degree. C for less than 10 minutes in an open-air atmosphere or under noble metal encapsulation, a green ceramic body formed from the powder mixture of which one ingredient is the .beta."-alumina seeds and the other ingredient is the matrix powder of a composition consistent with the formation of .beta."-alumina.The polycrystalline .beta."-alumina-containing ceramic bodies obtained by the method of this invention exhibit high density, low porosity, high strength, fine grain size, and low electrical resistivity.

Abstract: An inflation and adjustable pressure relief apparatus for the inflatable cuff of an endotracheal tube, the apparatus having an adjustably spring-biased relief valve to automatically release gas pressures from the cuff above a preselected pressure level and a manually operable spring-biased valve for increasing the gas pressure in the cuff.

Abstract: A dialyzer cartridge includes a resilient gasket defining a central hollow area, and first and second cross members affixed in and extending between the interior side walls of the gasket to divide the hollow area into first, second and third portions. The ends of a plurality of hollow fibers are embedded in respective cross members to extend across the second portion of the hollow between the first and third portions. A first fluid is introduced into the first portion to be transported through the fibers to the third portion and a second fluid is introduced into the second portion to flow about the fibers and thereby facilitate the process of dialysis between the interior and exterior of the fibers. The second portion of the hollow is sealed from the first and third portions by a pair of plates secured together with the gasket sandwiched therebetween.

Abstract: A protein-immobilizing hydrophobic polymeric membrane comprising an organic, hydrophobic polymeric substrate with a specific protein reactive group pendant therefrom in preselected concentration is disclosed. The protein reactive groups is a free group of a hydrocarbon chain which has one end thereof absorbed into the surface of said polymeric substrate; said free group, generally at the end of said chain, covalently bonding with a protein molecule. The concentration of protein reactive sites is sufficiently low that the polymeric substrate retains its hydrophobic character. An electrode coated with a protein-immobilized membrane, i.e., a membrane having a hydrocarbon chain to which a protein molecule is attached, provides, in conjunction with a reference electrode, an electrically sensitive system for measuring change in concentration of a compound in solution where said compound selectively reacts with the immobilized protein.

Abstract: A process for the removal and recovery of bismuth from oxidized particulate materials, such as flue dust residue and/or roasted concentrates, the process including selectively solubilizing bismuth with an acidic chloride leach at an elevated temperature and thereafter separating the solubilized bismuth from the remaining metallic values in the residue.

Abstract: Novel compounds of the formula ##SPC1##Wherein R is selected from the group consisting of carboxamidine, carboxylic acid, carboxamide, methyl formimidate, thiocarboxamide, carboxamidoxime, carboxamidrazone, and cyano. The compounds have been demonstrated to be useful by having a degree of antimetabolic activity.

Abstract: An improved method for synthesizing 1-(tetrahydro - 2-furanyl) - 5-fluorouracil from a silyl derivitive of 5-fluorouracil (bis - trimethylsilyl 5-fluorouracil) by reacting the same with 2-chlorotetrahydrofuran. The reaction is carried out at controlled conditions of temperature and under an inert gas. Yields in excess of 80% of the theoretical are obtained as calculated upon the starting amounts of 5-fluorouracil.

Abstract: A method of producing a sinterable refractory material having a low coefficient of thermal expansion and comprising essentially a dispersion of aluminum oxide throughout a silicon nitride matrix, herein called SIALON. The process includes obtaining aluminum and silicon from generally readily available raw material sources.

Abstract: A scanning radiographic system employing a multi-linear array. The system includes a source of electronic radiation, which is focused upon the multi-linear array. The multi-linear array includes radiation sensors each of which is adapted to generate an intensity signal as a function of the amount of radiation sensed thereby. Each sensor has associated therewith a means for holding or storing its respective intensity signals. The intensity signals thus held may be continually up-dated to reflect subsequent intensity signals resulting from additional radiation sensed by the respective sensors. An opaque object to be scanned by the radiographic system passes through the beam of radiation in a controlled fashion.