Abstract: Compounds of formula (I) are provided, wherein R.sup.1 represents OH or OCH.sub.3 ; R.sup.2 represents OH or H; R.sup.3 represents methyl, ethyl, propyl or allyl; X represents O, (H,OH) or (H,H); m represents 0 or 1; n represents 1 or 2; and pharmaceutically acceptable derivatives thereof; provided that when n is 1, then R.sup.3 is allyl or propyl. The compounds are indicated inter alia as immunosuppresive agents.

Abstract: The invention provides methods and apparatus for atomic emission spectroscopy and for mass spectrometry which make use of an inductively coupled radio-frequency plasma torch. A radio-frequency power supply supplies energy to a plasma induction coil via reflectometer means and a matching network. A signal indicative of reflected power generated by the reflectometer is used to set the frequency of the power supply to the resonant frequency of the matching network and plasma induction coil, thereby ensuring the maximum efficiency of power transfer irrespective of the state of the plasma. Preferably a solid state power amplifier is employed in conjunction with a lower power variable frequency oscillator. Means for ensuring proper ignition of the plasma while maintaining the frequency of the power generator within a governmentally specified frequency band are also provided.

Abstract: In a mass spectrometer, an aperture defining a beam path to a particle detector (4) is defined by a fixed aperture (5) and a cover (6) mounted on respective carriage assemblies (50,49) running along a beam 46. When a shaft (36) drives carriage (50), a rod (22) on carriage (49) is engaged by an end of a slot (21) of carriage (50), so that both carriages can be moved to a desired aperture location. After reaching this position, carriage (50) may be moved in the opposite direction, within a range defined by the length of the slot (22), without causing movement of carriage (49), to vary the amount by which member (6) covers member (5) and to thereby define a desired aperture width. A plurality of carriages can be coupled to one another in this manner to form a chain of apertures whose positions and widths may be varied independently using a single drive shaft (36). The fixed aperture (5) and cover ( 6) may be replaced by a pair of opposed aperture-edge defining members in the same plane.

Abstract: Compounds of formula (I), in which [R.sup.1 and R.sup.2 ], [R.sup.3 and R.sup.4 ] and [R.sup.5 and R.sup.6 ] represent a carbon-carbon bond or two hydrogen atoms; R.sup.2 additionally represents alkyl; R.sup.7, R.sup.8 and R.sup.9 represent groups including H or OH, R.sup.10 has various significances including alkyl and alkenyl; X and Y represent groups including O and (H, OH); R.sup.14, R.sup.15, R.sup.16, R.sup.17, R.sup.18, R.sup.19, R.sup.22 and R.sup.23 represent H or alkyl; R.sup.20 and R.sup.21 represent groups including O, (H, OH) and (H, O-alkyl), n is 1, 2 or 3, and in addition, Y, R.sup.10 and R.sup.23, together with the carbon atoms to which they are attached, may represent a heterocyclic ring, (with certain provisos) are described. Processes for making the compounds and pharmaceutical formulations containing them, e.g. for use as immunosuppressive agents, are also described.

Abstract: A sensor based on the technique of surface plasmon resonance (SPR) comprises an SPR device, a source of electromagnetic radiation from which radiation can be directed onto the device, and a detector to measure the intensity of radiation reflected from the SPR device. The electromagnetic radiation directed onto the SPR device contains both Transverse Electric-polarized and Transverse Electric-polarized components. A polarization analyzer is interposed between the device and the detector such that, at angles away from resonance, little or no light reaches the detector. The sensor is particularly useful in the qualitative and/or quantitative determination of biological, biochemical or chemical analytes.

Abstract: In the elemental analysis of an analyte present in a sample by optical or mass spectrometry, a nebulizer sprays the liquid sample into a chamber which has a wall transparent to infra-red radiation. Infra-red radiation from a heater external to the chamber is focused on to the droplets of sample as they emerge from the nebulizer, disrupting the droplets into smaller ones and evaporating solvent from them as they pass through the chamber. The thus desolvated sample stream is delivered into a plasma and the reaction accuracy within the plasma is qualified by the spectrometer.

Abstract: Particulate nedocromil sodium with a mass median diameter of from 5 to 10 .mu.m is useful as a medicament for inhalation.The particulate nedocromil sodium of the invention is particularly advantageous in that its dispersion, i.e. the proportion of particles which are capable of penetrating deep into the lung, is substantially greater than the dispersion of conventional powders having smaller mass median diameters.

Abstract: A quadrupole mass filter (1) includes a controllable RF oscillator (7) which follows any drift in the resonant frequency of a resonant circuit means (8), this circuit means (8) amplifying an alternating RF potential from the oscillator (7) and supplying it to the filter electrodes (2, 3, 4, 5). To ensure that the charge to mass ratio of the particles transmitted by the filter remains constant, a signal for controlling the amplitude of the oscillator (7) is corrected in response to any resonant frequency shift. This signal is also fed to DC supply means (12, 13, 15), to ensure that the amplitude of the DC potential applied to the electrodes (2, 3, 4, 5) remains in the correct ratio to the RF potential amplitude so that the filter resolution remains constant.

Abstract: An isotopic-ratio mass spectrometer comprises an r.f.

Abstract: An aerosol inhalation device, having a mouthpiece (12) and a canister (15) of pressurized hygroscopic medicament, the canister (15) being fitted at one end with a dispensing metering valve; wherein a protective barrier (19) is provided between the dispensing metering valve and the mouthpiece (12) so as to eliminate or substantially reduce blockage of the device.

Abstract: Angiotensin converting enzyme inhibitors have the formula Z(CH.sub.2).sub.n CHR.sub.1 COOCHR.sub.2 COOHin which Z is --SR.sub.3, --COCHR.sub.4 NHCOR.sub.5, ##STR1## or --NHCHR.sub.7 COOH, R.sub.4, R.sub.5, R.sub.6, and R.sub.7, which may be the same or different, are each phenyl or alkylphenyl C.sub.7-12,R.sub.4 is hydrogen, alkyl C.sub.1-6, NHR.sub.8 or (CH.sub.2).sub.p R.sub.9,R.sub.2 is (CH.sub.2).sub.m XR.sub.10, alkyl C.sub.1-6 optionally substituted by a saturated 5- or 6-membered carbocyclic or heterocyclic ring, alkylhalo C.sub.1-6, alkylcyano C.sub.1-6, or alkyl phenyl C.sub.7-12, the phenyl being optionally substituted by NO.sub.2 or NH.sub.2,X is O, S(O).sub.q, C.dbd.O or NR.sub.11, andR.sub.10 is alkyl C.sub.1-6, alkylhalo C.sub.1-6, alkoxy C.sub.1-6, alkoxy C.sub.1-6 substituted by halogen, alkanoyl C.sub.1-6, S(O).sub.r R.sub.12, NR.sub.13 R.sub.14, phenyl, alkylphenyl C.sub.

Abstract: A collision cell for observing the emission spectrum of ions. The substantially enclosed collision cell (8) is bounded by a wall (46), the wall having an entrance aperture (47) and an exit aperture (29) through which an ion beam (5) may be passed to traverse the collision cell, and has an observation region (15) therein adjacent to the entrance aperture and a first window (22) in the wall through which radiation generated in the observation region may pass, and, disposed adjacent to the exit aperture and in communication with the observation region, an exit region (16) comprising radiation-trapping means for minimizing the transmission to the first window of radiation generated in the exit region. The collision cell may be incorporated in a conventional mass spectrometer.

Abstract: A method of compacting and administering a powdered inhalation medicament for use in an inhalation device includes compacting a body of loosely powdered inhalation medicament such that the degree of compaction is sufficient to hold the body together solely due to the force of compaction and placing the compacted body into the inhalation device and abrading the compacted body to obtain a plurality of unit doses of the medicament.

Abstract: Pharmaceutical compositions suitable for administration by inhalation and containing pentamidine, or pharmaceutically acceptable salt thereof, in powder form. Such compositions include pressurized aerosol compositions and nonpressurized power compositions. Also described is finely divided powdered pentamidine with a mass median diameter in the range 0.01 to 10 microns and a method for the prevention or treatment of pneumo-cystis carinii pneumonia which comprises administration by inhalation to a patient having or susceptible to that condition of a therapeutically effective quantity of pentamidine, or a pharmaceutically acceptable salt thereof, in powder form.

Abstract: An on-line mass spectrometric method and apparatus for the determination of the isotopic composition of at least oxygen, hydrogen and nitrogen in a compound or mixture of compounds. A mixture contained in syringe 6 is injected through injector 7 on a chromatographic column 1. Compounds eluting from the column 1 pass into a catalytic reactor 14 containing carbon and are decomposed to produce carbon monoxide, molecular nitrogen, and molecular hydrogen. These gases are analyzed by an isotope-ratio mass spectrometer 4 so that the isotopic composition of the oxygen, nitrogen and hydrogen comprised in the original compound can be determined. A second chromatographic column 24 may be provided to separate carbon monoxide and nitrogen before they are passed into the spectrometer 4, thereby allowing a low resolution spectrometer to be used for the analysis of both gases at m/e 28 daltons.

Abstract: A sensor for electrical charge fabricated as an integrated circuit and including an electrode (1) for receiving charge, a potential-sensitive switching device (2) for generating a pulse whenever the charge received on the electrode (1) is sufficiently great, a counting device (4) for counting the number of times the switching device operates, and a member (3) for restoring the potential on the electrode (1) to its initial potential each time the switching device (3) operates and/or continuously towards its initial potential. An integrated circuit having an array of such sensors and digital logic for controlling their operation is included. The array may be used as a multiple-channel detector for charged particles, particularly as a detector for electrons emerging from a channel plate electron multiplier. Dispersive particle and photon spectrometers, especially mass spectrometers, using such a detector are also provided.

Abstract: A spark generator suitable for use in an optical emission spectrometer, and capable of generating a spark in a spark gap formed between an electrode and a sample to be analyzed, comprises a generator for generating a current of programmable amplitude in the spark gap in each of a series of discrete time intervals. The spark generator according to the invention is advantageous when compared with conventional spark generators in that it enables a higher degree of choice and control in the form of the spark. In particular, it enables the amplitudes of various portions of the spark to be independently varied, thus permitting the shape of the spark to be tailored to the particular analysis being performed. Also described are methods of optical emission spectroscopy which make use of the advantageous properties of the spark generator.

Abstract: An optical device for the spectral analysis of a light source which comprises a spectrograph assembly including a dispersive element, and a classical collimator. The spectrograph assembly supplies a complete intermediate spectrum at the object focus of the classical collimator and the classical collimator reforms, at its image focus, an image of the dispersive element. The spectrograph assembly is preferably a Czerny-Turner or other type of spectrograph comprising an entry slit, two juxtaposed concave mirrors of the same focal length and a dispersive element placed strictly in the common focal plane of the two mirrors. Most preferably, the classical collimator is the first mirror of the second, similar spectrograph assembly. The device is most advantageous in that it is readily useable for both simultaneous and sequential spectroscopy.

Abstract: There is described finely divided nedocromil sodium, comprising a therapeutically effective proportion of individual particles capable of penetrating deep into the lung, characterized in that a bulk of the particles which is both unaggolomerated and unmixed with a coarse carrier, is sufficiently free flowing to be filled into capsules on an automatic filling machine and to empty from an opened capsule in an inhalation device.There is also described a method of making the fine particles and pharmaceutical formulations containing them.