Abstract: The invention relates to a device for use in methods of assay, for example those involving fluorescent moieties. The device possesses a cavity or cavities into which the sample liquid may be drawn by capillary action. Each cavity is formed from two transparent solid plates (35,36): one (36) is adapted to act as a waveguide and carries a suitable immobilized reagent on its surface within the cavity; the other (35) carries on its external surface and optionally also on part only of its internal surface a layer of light-absorbing material (37). The invention also relates to a method of manufacturing devices according to the invention, and to a method of assaying for a ligand in a sample using a device according to the invention.

Abstract: An adjustable-resistance anti-siphon device for a cerebrospinal fluid shunt is provided. The device has a substantially rigid housing having an internal cavity which contains a first chamber and a second chamber, the first chamber having at least one flexible wall, an inlet port and an outlet port, the ports passing through apertures in the housing; the second chamber being gas-filled and being in pressure communication with at least a portion of the at least one flexible wall of the first chamber; and gas pressure control means connected to said gas-filled chamber whereby the pressure in said gas-filled chamber may be adjusted.

Abstract: The vehicle comprises a sample receiving reservoir (15), a plurality of test stations each comprising an FCFD or other capillary fill sensor cell (3), and passage (22) for providing fluid communication between the reservoir and a conduit with which end portions of said cells communicated such that in use sample from the reservoir may be fed to the plurality of cells substantially simultaneously. The vehicle makes it easier to know time zero for each assay. Passage (22) providing fluid connection may comprise at least one pore in a wall of the reservoir, the or each pore being of a size such that surface tension of the liquid normally prevents escape of ligand. Rotation of the vehicle breaks surface tension and liquid is released into the conduit.

Abstract: A method of treating the surface of an optical structure which comprises forming on the surface a thin layer of organic polymer using a solvent casting technique. Preferably the process includes the subsequent treatment of the polymer layer with a solution of a specific ligand.Complex formation between the bound ligand and its specific binding partner present in a sample to be analyzed alters the optical properties of the diffraction grating surface and the change can form the basis of an assay method.

Abstract: A specifically-reactive sample-collecting and testing device possessing a cavity or cavities each having a dimension small enough to enable sample liquid to be drawn into the cavity by capillary action, wherein a surface of the cavity carries an immobilized reagent appropriate to the test to be carried out in the device, and wherein said surface is a surface of a transparent solid plate to act as a light-transmissive waveguide and forming a wall of the cavity, said plate having an edge which is substantially optically smooth and transverse to the plane of the plate.

Abstract: A method and apparatus for analysing the spectrum of light reflected by a reflecting structure (24) in which the effect upon the analysis results of variation in the angle between the reflecting structure and the incident beam (22) is minimised. The method and apparatus may utilise a dispersive element (26) constructed and arranged so as to minimise the effect of the variations. The method and apparatus may also utilise a calibration technique in which light with a known spectrum is reflected off the reflecting structure and analysed so that compensation may be made for the effect of the variation.

Abstract: A multistation charging system is provided for charging batteries within a plurality of cordless tools, appliances or the like, each of which has at least one rechargeable battery therein. A plurality of modules, which act as charging stations, are arranged substantially adjacent to one another. Normally closed pairs of conductive contacts are provided in each of the modules. The electrical pairs of contacts in the modules are connected in a series circuit arrangement with each other. On one of the modules, electrical connection is provided to a single current regulated solid-state charging device which produces charging current pulses. The device may alternatively be in the one module. Each of the modules removably supports a respective tool or appliance and each tool or appliance has means for electrically connecting the respective battery therein within the series circuit arrangement and in series therewith only one wall outlet or a.c. power connection is required.

Abstract: Methods are provided for stabilization and purification of proteins produced in host cell systems. The methods provide for significant stabilization of any unfused non-bacterial protein that is produced in the same host cell that is producing an aggregate-forming fusion protein or any aggregate-forming protein.

Abstract: Methods and compositions for the insertion and molecular cloning of RNA in DNA cloning vectors are described. RNA molecules to be cloned are modified by the ligation of oligonucleotide linkers onto the termini of the RNA molecule using T4 RNA ligase. Such linkers may be composed of DNA, RNA, or mixtures of each and facilitate the insertion and ligation of the RNA species into a DNA cloning vector. The resulting recombinant vectors are used to transform host cells which provide for the generation of multiple DNA copies of the RNA molecule.

Abstract: This invention is direction to the production of novel plant genotypes or lines which produce increased free tryptophan levels and are resistant to inhibition by analogs which normally inhibit the activity of the enzyme anthranilate synthase before alteration. This invention further relates to genes encoding such exzymes, and to processes for utilizing these novel genes and enzymes. Further products of the invention include plants, plant tissues and seeds which exhibit resistance to such analogs and overproduce tryptophan resulting from expression of genes encoding analog resistant anthranilate synthase enzyme.

Abstract: DNA cloning and expression vectors capable of replication in a microbial host comprising from upstream to downstream (a) at least one promoter; (b) a translation start codon; (c) a cloning segment which provides a means for inserting nucleic acid sequences and (d) a sequence coding for a detectable gene product, out of translational phase with the translation start codon but capable of being readjusted to the translational phase of said start codon by insertion into the cloning segment of nucleic acid sequences containing the proper number of nucleotides for readjustment, said gene product providing a means for detecting expression of inserted nucleic acid sequences.

Abstract: A disposable film developing assembly comprises a container having a developing chamber and an additional chamber upstream thereof for receiving a film wrap. A developer envelope containing film treating fluid is disposed inside the container, tabs on the envelope being connected to the container for tearing open the envelope and permitting the release of fluid therefrom upon a withdrawal of the envelope from the container. Linking elements for coupling a film to the envelope are provided, whereby the film is drawn from the film wrap into the developing chamber during a withdrawal of the envelope from the container. The envelope has a fluid containing pocket with a pair of longitudinally staggered extensions projecting from the longitudinal edges of the envelope towards the longitudinal edges of the container. Tabs are connected to the envelope at the extensions of the envelope pocket and are folded at creases over the respective extensions.

Abstract: A charger for batteries includes a a charging station, which includes a housing. A casing end having an open portion through which batteries to be charged are to be inserted is provided. A constant tension spring within the casing urges the batteries outwardly of the casing. A lid is provided adjacent to the open end of the casing, the lid being movably, pivotably supported on the casing. A stop member is provided on the housing, the stop preventing the lid from being moved to its completely open position when the casing is supported on the housing. A latch arrangement retains the lid in a closed orientation. The batteries in the casing are retained therein by a portion of the lid whenever the lid is pivoted away from its completely open position. Contact means are provided between the housing and casing to provide a path for charging current. A multiple of charging stations can be provided, the multiple stations being electrically and mechanically connected.

Abstract: A wrap-around auxiliary keyboard having (1) housing, (2) keys positioned in the housing and (3) circuitry means in the housing. The housing has a base and at least one extension extending from the base. The base and extension(s) are shaped and positioned with respect to each other so as to be able to wrap-around a primary keyboard.

Abstract: A battery charger which includes terminals for connection to an electric power source, an electrical charging circuit and an operative arrangement for connecting at least one rechargeable battery cell in series with the charging circuit across the terminals. The battery charger has a charging circuit which includes a first resistor, a second resistor, a third resistor and a rectifier, constituted by at least one diode, in series. A first transistor, which has a collector-emitter path and a base-emitter path, is operatively connected so that the base-emitter path is connected in parallel with the first resistor. A fourth resistor is provided, the fourth resistor being connected in series with the collector-emitter path of the transistor and the third resistor.

Abstract: A power supply which includes terminals for connection to an electric power source, a storage capacitance, an electrical charging circuit and an operative arrangement for connecting storage capacitance in series with the charging circuit across the terminals. The power supply has a charging circuit which includes a first resistor, a second resistor, a third resistor and a rectifier, constituted by at least one diode, in series. A first transistor, which has a collector-emitter path and a base-emitter path, is operatively connected so that the base-emitter path is connected in parallel with the first resistor. A fourth resistor is provided, the fourth resistor being connected in series with the collector-emitter path of the transistor and the third resistor.

Abstract: A power supply which includes terminals for connection to an electric power source, a storage capacitance, an electrical charging circuit and an operative arrangement for connecting the storage capacitance in series with the charging circuit across the terminals. The power supply has a charging circuit which includes a first resistor, a second resistor, a third resistor and a rectifier, constituted by at least one diode, in series. A control stage includes a first transistor, which has a collector-emitter path and a base-emitter path. The transistor is operatively connected so that the base-emitter path is connected in parallel with the first resistor. A fourth resistor is provided, the fourth resistor being connected in series with the collector-emitter path of the transistor and the third resistor.

Abstract: A battery charger which includes terminals for connection to an electric power source, an electrical charging circuit and an operative arrangement for connecting at least one rechargeable battery cell in series with the charging circuit across the terminals. The battery charger has a charging circuit which includes a first resistor, a second resistor, a third resistor and a rectifier, constituted by at least one diode, in series. A first transistor, which has a collector-emitter path and a base-emitter path, is operatively connected so that the base-emitter path is connected in parallel with the first resistor. A fourth resistor is provided, the fourth resistor being connected in series with the collector-emitter path of the transistor and the third resistor.