Abstract: This invention relates to a method of directing a therapeutic agent to selected cells, wherein a complex is formed between a polysaccharide capable of interacting with a cell receptor and a therapeutic agent. The resulting complex is administered to a subject, and permitted to be internalized into the selected cells through a process known as receptor mediated endocytosis (RME). The polysaccharide may be, for example, arabinogalactan, gum arabic, mannan or hydrolysis products thereof; the therapeutic agent may be, for example, an antiviral agent, a nucleic acid, hormone, steroid, antibody, chemoprotective or radioprotective agent. The cell receptor may be for example, the asialoglycoprotein receptor or the mannose receptor.

Abstract: A headset speaker is provided in which a driver is provided in the dome of a speaker earcup and the dome has at least one vent aperture. The vent hole is closed by a movable closure having a corresponding opening therein that permits the size of the opening into the dome to be logarithmically varied between a fully open and fully closed position. A Thuras tube tuned to enhance bass frequencies is provided extending between the driver side and rear of the earcup. An opening to the Thuras tube remains fully closed by the movable closure unless the cup vent aperture is fully closed at which time the Thuras tube is opened.

Abstract: A flexible magnetic pad is provided with constantly alternating polarity zones which therapeutically effect blood vessels to increase blood flow, irrespective of the orientation of any blood vessel with respect to the pad, the polarity zones being arranged in an alternating pattern throughout the pad.

Abstract: A single guide wire system for use in continually directional drilling of boreholes, includes a guidewire extending generally parallel to the desired path of the borehole. The guidewire is connected at a first end to one side of a reversible source of direct current, and at a second end to ground. A second side of the DC source is also connected to ground. A known current flow in a first direction for a first period of time and in a second direction for a second period of time produces corresponding static magnetic fields in the region of the borehole. The vector components of the fields are measured in the borehole by a 3-axis magnetometer, and from these vector components the effects of the Earth's magnetic field are canceled and the distance and direction from the borehole to the guidewire are determined. These values permit control of further drilling of the borehole along a desired path.

Abstract: A flexible magnetic pad is provided with constantly alternating polarity zones which therapeutically effect blood vessels to increase blood flow, irrespective of the orientation of any blood vessel with respect to the pad, the polarity zones being arranged in an alternating pattern throughout the pad.

Abstract: A method and apparatus for drilling a borehole under an obstacle including placing a solenoid on the surface of the earth at the far side of the obstacle, near a preselected borehole exit location. A drilling assembly at an entry location on the near side of the obstacle is driven to produce a borehole which is directed under the obstacle toward the exit location. Initially, guidance of the drilling assembly is by conventional survey techniques, but when the borehole moves to within about 100 meters of the solenoid, the solenoid magnetic field is used to guide the drilling operation.

Abstract: A method and apparatus for determining the distance and direction to a borehole containing ferromagnetic material includes placing a sensor package in a second nearby borehole and measuring three vector components of the static magnetic field perturbations of the earth's magnetic field caused by the ferromagnetic material. The sensor package is moved within the second borehole to obtain a plurality of magnetic field measurements, and the measured components are then projected onto a system of fixed coordinates whose orientation in space is known. The relative direction from the second borehole to the first is determined from the vector components, and the magnitude of the resultant in the direction of the first borehole is then determined from the fixed coordinate system.In a modification, the sensor package includes two spaced magnetometers for measuring vector components of the magnetic field perturbations.

Abstract: Chemoactive radioprotectants are coupled to carrier molecules capable of binding cell receptors to form complexes that can be directed to specific non-target cells in a mixture of cells prior to radiation of the mixture so that target cells are selectively destroyed while the non-target cells are protected from radiation. Radioprotection of non-target cells is provided by using chemoactive radioprotectant complexes.

Abstract: Methods for determining the distance from a borehole to a nearby, substantially parallel target well for use in guiding the drilling of the borehole, including positioning a magnetic field sensor in the borehole at a known depth and providing a magnetic field source in the target well. The wells may be vertical or horizontal, and the source preferably is a solenoid movable in the target to a location at approximately the same depth as that of the sensor.The distance between the borehole and the solenoid is determined, in one embodiment, by moving the solenoid to depths above and below the depth of the sensor, and detecting maximum field vectors. The distance the solenoid moves between the maxima is the distance between the wells. In another embodiment, the ratio of solenoid magnetic field vectors is used to determine the ratio of the difference in depth z between the solenoid and the sensor to the lateral distance R between the wells. This ratio z/r is then used to determine the separation of the wells.

Abstract: A substantially purified arabinogalactan, its degradative products and selected modifications thereof have been found to act as carriers for delivering therapeutic agent to cell receptors capable of receptor mediated endocytosis (RME). The arabinogalactan and its degrative products once derivatived are capable of forming a complex between the therapeutic agent and the polysaccharide such that the complex retains the ability to recognize and bind to the RME receptor.

Abstract: A method of fabricating thin-film magnetic recording heads or "sliders" employs the step of slicing a wafer containing like-oriented transducers into chunks, each chunk containing at least a minimum number of rows of transducers such that the amount of bow induced in the chunk is minimized. Following the chunk slice, one of two methods may be followed to yield precisely-lapped single rows of sliders. In the first method, the chunk is bonded to a rigid support piece at one end, and to a rigid carrier tool at the other. The row bonded to the carrier is then sliced away from the chunk and lapped while attached to the carrier. The steps of bonding, slicing, and lapping are then repeated for each row in the chunk. In the second method, the chunk is bonded to a rigid carrier tool at one end, and the row at the other end is then lapped and sliced off. The steps of lapping and slicing are repeated for each row in the chunk.

Abstract: The present invention is a joint assembly for allowing relative rotational movement of a camera relative to a stationary base structure. The assembly has a first flexible member which allows the camera to pan the surrounding are and a second flexible member which allows the camera to tilt. Each flexible member has a first surface facing a first direction and second surface facing a second opposite direction. One end each flexible member is folded over onto itself so that a portion of the second surface faces the first direction. The flexible members are constructed in an essentially radial shape to define a radial path. When an end of a flexible member moves along the arcuate path the member rolls over itself. That is, the portion of the flexible member that is rolled over, has its second surface facing the first direction instead of the second direction.

Abstract: A new class of magnetic resonance (MR) contrast agents are described whose in vivo biodistribution is based upon the ability of certain cells to recognize and internalize macromolecules, including the MR contrast agents of the present invention, via a process which substantially involves receptor mediated endocytosis. The RME-type MR contrast agents described herein comprised of biodegradable superparamagnetic metal oxides associated with a variety macromolecular species, including but not limited to, serum proteins, hormones, asialoglycoproteins, galactose-terminal species, polysaccharides, arabinogalactan, or conjugates these molecules with other polymeric substances such as a poly(organosilane) and dextran. One of the advantages or these MR contrast agents is that they may be selectively directed to those cells which bear receptors for a particular macromolecule or ligand and are capable of undergoing receptor mediated endocytosis.

Abstract: A transducer assembly includes a bi-directional transducer coupled to an ear mold for transmitting and receiving sounds from a remote location. A by-pass channel is provided in the ear mold for ambient sounds which by-pass the transducer.

Abstract: A new class of magnetic resonance (MR) contrast agents are described whose in vivo biodistribution is based upon the ability of certain cells to recognize and internalize macromolecules, including the MR contrast agents of the present invention, via a process which substantially involves receptor mediated endocytosis. The RME-type MR contrast agents described herein comprised of biodegradable superparamagnetic metal oxides associated with a variety of macromolecular species, including but not limited to, serum proteins, hormones, asialoglycoproteins, galactose-terminal species, polysaccharides, arabinogalactan, or conjugates of these molecules with other polymeric substances such as a poly(organosilane) and dextran. One of the advantages of these MR contrast agents is that they may be selectively directed to those cells which bear receptors for a particular macromolecule or ligand and are capable of undergoing receptor mediated endocytosis.

Abstract: A stochastic excitation, SQUID detection system for determining the frequency response of a sample. A pair of counterwound detection coils are adjacent to an excitation coil. The sample is selectively placed in one of the detection coils for taking measurements. The SQUID sensor is a broadband, high sensitivity device which enables the frequency response of the sample to be determined over a wide bandwidth with a single measurement.

Abstract: The invention relates to a method for the targeting of a therapeutic agent to a specific population of cells, wherein a complex is formed between the therapeutic agent and a polysaccharide capable of interacting with a cell receptor, and wherein the resulting complex is internalized into the cell by receptor mediated endocytosis (RME). In one embodiment of the invention, a complex of a therapeutic agent containing iron and the polysaccharide arabinogalactan may be formed and used to deliver iron specifically to hepatocytes by RME.

Abstract: A thin film dc SQUID and its driving electronic circuitry configured with very high symmetry, having a SQUID loop formed with four holes (24, 24, 26, 27) at the respective ends of crossed slits (22, 23). Each of these holes forms a single turn secondary coil for symmetrically arranged pairs of modulation coils and signal coils. The geometrical placement of the modulation coils with respect to the signal coils results in a device which nominally has no mutual inductance between the two groups of coils when the SQUID is biased for normal operation. The external driving circuit (75-85) is configured to preserve the highly balanced nature of the SQUID and forces an equal magnitude of current to flow in all four of the bias leads.

Abstract: The preparation and isolation of biodegradable superparamagnetic MR imaging contrast agents for the vascular compartment is described. These aggregates are comprised of individual biodegradable superparamagnetic metal oxide crystals which aggregates have an overall mean diameter less than about 4000 angstroms. The preferred vascular imaging contrast agent is comprised of aggregates of iron oxide crystals having an overall mean diameter less than about 500 angstroms. These contrast agents may be associated with a macromolecular species, which assist, among other things, in the preparation of these extremely small materials, and may be dispersed or dissolved in a physiologically acceptable medium. Preferred media also stabilize the materials against further aggregation even under harsh sterilization conditions.

Abstract: The present invention is directed to a circuit and method for nullifying a drop in the voltage across an MR head caused a parasitic cable resistance. The invention uses local modeling of the cable resistance in order to generate a nulling voltage, equal in magnitude to the voltage across the cable resistance. The magnitude of the nulling voltage is adjusted as the resistance of the MR head varies within a population of heads. The nulling voltage is added to the bias voltage, in order to negate the effect of the cable resistance.