Abstract: Optical apparatus for measuring the topographic properties of a surface uses a beam of coherent radiation which is split by a beam splitter (2) into a reference beam and a probe beam. The probe beam at is modulated by a Bragg cell which is switched at two frequencies (.omega..sub.1,.omega..sub.2). A detector (6) recombines the components of the probe beam after reflection to produce a plurality of tone bursts the phase differences of which correspond to variations in the surface topography.

Abstract: A method of manufacture of thin film devices involves the sputtering of an epitaxial barrier layer (11) of a metallic oxide such as magnesia on to which a further epitaxial thin film (12) is deposited. The substrate is preferably alumina and the thin film may be a high temperature superconductive compound of yttrium, barium, copper and oxygen.

Abstract: A method of producing a magnetic resonance image of a defined region of an object by an echo volumar imaging process including subjecting the object to an initial selection process to select a thick slice within the object to produce an active volume of spin magnetisation subjecting the active volume so defined to a combination of 180.degree. RF pulses and suitably modulated x, y and z gradients to produce an echo volumar image.

Abstract: Controlled release compositions comprising a water swellable carrier and an active material having crenellated surface exhibit improved release properties. Suppositories and pessaries of generally cylindrical shape having four or five crenellations spaced equally around the perimeter and extending substantially along the length of the cylinder are preferred. Suppositories comprising four or five rounded crenellations which release morphine sulphate are especially useful.

Abstract: Novel devices for the controlled release of active materials especially pharmaceutical are formed from at least two interpenetrating pieces. The male piece is water swellable and swells to disengage the female piece. The female piece is preferably formed from a thermoplastic, e.g. LDPE or from a soluble material such as gelatin which is rendered impermeable by an external coating of a hydrophobic material such as PVC. The devices find particular application as oral dosage forms for use in man.

Abstract: The invention provides a method and a corresponding instrument for measuring the direction of a remote source of radiation, the instrument comprising a support, a detector head rotatably mounted thereon for rotation about a fixed axis, and a position-indicator means which provides an output signal indicating the rotational position of the detector head, the detector head being provided with a detector sensitive to radiation emitted by the remote source and with optics for forming an image of the source which transits across the detector as the detector head rotates, the image-forming optics being such that the image comprises two line-image components which extend transversely to the transit direction and which are oppositely inclined to that direction, and the detector being arranged, in response to the transit across it of each line-image component, to cause the instantaneous angular position of the detector head as indicated by the position indicator to be recorded, there being further provided computer wh

Abstract: The present invention relates to an apparatus for the treatment of or the inhibition of retinopathy of prematurity and to a method for treating or for inhibiting retinopathy of prematurity. The apparatus provided in accordance with the present invention includes a component or system for providing substantially only red light. Thus, light is provided having a wave band of approximately 612 nm or more. Furthermore, at least the patient's head is received in a device that limits the light which reaches the patient's eyes to the aforementioned red light. Thus, the patient is allowed to see substantially only red light.

Abstract: The invention provides a controlled connection, or heat switch, between a source of cryogenic cooling and an item which is to be cooled, using control valve means which is not itself subjected to the cryogenic temperatures involved.

Abstract: A prosthetic femoral component (40) for the knee joint has a body (41,42) defined between elongate articulation and securement surfaces (43; 44,45), the articulation surface (43) being convexly spherically shaped and the securement surface having major and minor areas at opposite end portions, the major area (44) being essentially concavely spherically concentric with the articulation surface to form a shell body part (41), and the minor area (45) being essentially planar extending chordally of the articulation surface. A bone-penetrating pin (46) preferably extends radially from the major securement surface area in a direction parallel to the longitudinal direction of the neighbouring minor area. A related surgical tool (50) for shaping the femoral condyle has a rotary cutter (52) to provide a cut bone surface complementing the component major area, and a guide spigot (53) projecting adjustably coaxially within the cutter.

Abstract: A spray arrangement including means to form and direct a spray of liquid droplets and means to apply an electrostatic charge to droplets in said spray, said charge applying means including an insulating body to support a spray-charging electrode in association with the spray-forming means, the spray-forming means [10] forming the spray hydraulically, the body [20] having a smoothly-constricted bore [26, 27, 28] for the free passage of spray with the electrode [23] housed to expose only inward-facing electrode surface [28] as the constriction to passing spray [40] for the acquisition of charge therefrom, the bore surface turning back upon itself [29] as it expands beyond the constriction to form an end of the body, the end of the body where the surface turns back upon itself [29] and the part of the bore remote from said end being formed to assist the shedding of liquid [22, 51, 52].

Abstract: An attenuated enterovirus or rhinovirus, suitable for use as a vaccine, has a reversed base pairing in the part, or in a part corresponding to the part, of the 5' non-coding region of the genome of poliovirus type 3 Leon strain shown below: ##STR1## A suitable attenuated poliovirus has the bases G and C at positions 469 and 534 respectively for a type 1 or type 2 poliovirus or at positions 472 and 537 respectively for a type 3 poliovirus.

Abstract: To improve its gas-permeability, a contact lens, which may be of any normal material, even a gas-impermeable material such as polymethylmethacrylate, is microperforated with 66000 holes distributed in equispaced sectors leaving unperforated the central (optically important) part and the outermost rim of the lens. With a smaller hole size, some one million holes can be accommodated. In a modification, some or all of the holes go only part way through the thickness of the contact lens.

Abstract: Compounds of formula (II) ##STR1## wherein R.sub.1 and R.sub.2 are each separately selected from hydrogen, alkyl, alkenyl and alkynyl groups having up to a maximum of four carbon atoms and being unsubstituted, and alkyl, alkenyl and alkynyl groups having up to a maximum of three carbon atoms and being substituted by one, or in the case of fluoro by one or more, substituents but with the proviso that when R.sub.1 is hydrogen then R.sub.2 is hydrogen or methyl, or R.sub.1 and R.sub.2 together constitute an ethylene bridging group, and R.sub.3 is a group which under physiological conditions undergoes elimination with the formation of a 3,5-dioxopiperazinyl ring, with the further proviso that the compound is in the meso or erythro configuration when each of R.sub.1 and R.sub.2 is the same or different unsubstituted or substituted alkyl, alkenyl or alkynyl group, and salts thereof with a physiologically acceptable inorganic or organic acid, are of value as prodrugs, particularly for effecting cardioprotection.

Abstract: Communication channels provided by the Integrated services Digital Network (ISDN) usually carry 64 Kbits/sec in each direction and are therefore unsuitable for data traffic at higher rates. This difficulty can be overcome by assembling ISDN channels to form channels having a higher bit rate. However problems arise, for example, in the transmission of data packets where the bit-rate required changes frequently and therefore the number of channels grouped together must be changed often. These problems are tackled as now described. Data from different data streams to be transmitted is read into respective buffers in a RAM. ISDN channels are grouped into channels known as slots and U-channels, respectively, and each U-channel transmits a respective data stream. Data from the buffers are assembled into frames, corresponding to an ISDN frame in a frame store by a microprocessor.

Abstract: An apparatus for forming a reconstituted food product is provided including at least one transfer hopper having a reciprocating bottom for supporting pieces of the food product at a loading location, a control member for reciprocating the bottom so as to alter the height of the bottom in relation to a load in the hopper thereby keeping a drop height of successive pieces of food product into the hopper within predetermined limits. A drive mechanism is provided for moving the hopper from a food product loading location to a discharge location. A mould is disposed at the discharge location and aligned with the hopper. A displacement member for displacing material from the hopper into the mould is provided.

Abstract: Measurements of the permittivity of samples over a very wide frequency range and a wide temperature range have previously involved such problems as changing parts of the measuring equipment in different regions of the frequency range, substituting one of the components of a bridge used as part of the equipment to obtain bridge balance, and limited permittivity resolution. The present invention employs a capacitance bridge formed by a sample held between electrodes, a series capacitor and a detector comprising a high input impedance amplifier and correlators. The bridge is balanced by applying voltages of known relative amplitude and phase constructed from outputs having relative phases of 0.degree., 90.degree. and 180.degree. of two phase-locked oscillators. The voltages are constructed using phase shifters, attenuators and summer-driver circuits. At low frequencies the applied voltages are obtained from a waveform synthesizer.

Abstract: A poultry-handling assembly is provided which includes a pair of rotors arranged side-by-side for rotation about a vertical or predominantly vertical axis. Each rotor includes a central core upon which are arranged groups of guide elements spaced apart around the central core. In operation, the guide elements of each group lie closely adjacent and/or abut and/or intermesh with the guide elements of the other rotor of the pair. In operation a drive elements contra-rotate the two rotors enabling them to gather or accept poultry into the assembly.

Abstract: Method of making a coherent film of silicon carbide on a surface, comprising forming a solution in the solvent of from 0.05 to 0.3 moles alkoxy silicon per mole of water, the solution also containing an acid catalyst and a carbonaceous material in the ratio 1 to 3 moles carbon per mole of silicon. Hydrolysis is allowed to occur followed by removal of volatile material after hydrolysis at this or an earlier stage; applying the solution to the surface; and thereafter heating at at least 1300.degree. C. The solvent comprises 0.3 to 1 mole of acetone per mole of water.

Abstract: To derive NMR imaging information an object is subjected to a static magnetic field on which is superimposed a sinusoidally time varying magnetic gradient field. A sequence of narrow 90.degree. rf pulses are applied around the instants when the gradient field has a zero value. The rf pulses have relative phase quadrature such that excited nuclei precess with accumulated phase in each sequence.

Abstract: Pharmaceutical excipients useful in dry powder inhalents comprise particles having a rugosity (measured by air permeametry) of less than 1.75. The use of these carriers increases the amount of drug injested by the patient using a dry powder inhaler. The preferred excipients are crystalline sugars such as lactose which may conveniently be prepared by controlled crystallisation from an aqueous medium.