Abstract: An electrochemical cell for detecting a gas from the surrounding environment. The cell comprises an electrolyte and a sensing electrode which is in fluid communication with the electrolyte and the gas to be detected, when present. The cell further comprises a counter electrode in fluid communication with said electrolyte, and also a source of reactant gas provided in a cavity adjacent to the counter electrode, wherein reaction of the gas to be detected at the sensing electrode results in reaction of the reactant gas at the counter electrode and wherein the cavity is formed of or comprises a membrane. The cell may also have a wick extending between the sensing electrode and the counter electrode in an axial direction and a reservoir surrounding the wick.

Abstract: An electrochemical cell for detecting a gas from the surrounding environment. The cell comprises an electrolyte and a sensing electrode which is in fluid communication with the electrolyte and the gas to be detected, when present. The cell further comprises a counter electrode in fluid communication with said electrolyte, and also a source of reactant gas provided in a cavity adjacent to the counter electrode, wherein reaction of the gas to be detected at the sensing electrode results in reaction of the reactant gas at the counter electrode and wherein the cavity is formed of or comprises a membrane. The cell may also have a wick extending between the sensing electrode and the counter electrode in an axial direction and a reservoir surrounding the wick.

Abstract: The present invention provides a colorimetric gas detector comprising a substrate bearing a material that can react with a gas in an atmosphere being monitored and wherein the reaction causes the material to change the radiation at which the material absorbs or radiates radiation (the color-change material). The material is located in at least one discrete area of the substrate. By providing the color change material in discrete areas, the amount of such material can be reduced and different types of color-change material can be included on a common substrate to detect two or more gases simultaneously.

Abstract: There is disclosed a method of operating a colorimetric gas detector system that comprises a substrate (1) bearing a material (12) that can react with a target gas to produce a change in the wavelength of radiation absorbed or transmitted by the material (“color-change material”). The method involves: a) applying onto a region (15) of the substrate that includes color-change material a chemical of predetermined concentration that reacts directly or indirectly with the color-change material to produce a change in the wavelength of the radiation absorbed or transmitted by the material; b) detecting the radiation absorbed or transmitted in said region (15) at a wavelength absorbed or transmitted by the reaction product of the color change material with the chemical, and c) generating a signal in accordance with the amount of radiation detected at the second wavelength, said signal being dependent on the amount of color-change material on the substrate.

Abstract: The present invention provides a colorimetric gas detector comprising a substrate bearing a material that can react with a gas in an atmosphere being monitored and wherein the reaction causes the material to change the radiation at which the material absorbs or radiates radiation (the color-change material). The material is located in at least one discrete area of the substrate. By providing the color change material in discrete areas, the amount of such material can be reduced and different types of color-change material can be included on a common substrate to detect two or more gases simultaneously.

Abstract: A method and apparatus for gas detection uses a sensor such as an electrochemical (EC) cell and includes a feedback control loop to control a pump to establish a first predetermined gas flow rate to the EC cell. The concentration of the gas at the first predetermined flow rate is measured. If the detected concentration exceeds a predetermined Alert value at the first flow rate an Initial Warning without remedial action is generated, and, the system then changes the gas flow rate before an Alarm is indicated. An Alarm is signaled only if the system verifies the first measurement. Preferably the first flow rate is set to optimize the measurement accuracy of the EC cell being used, and the second flow rate is lower than the first. Verification of an Alarm at the first flow rate may be conducted quickly by a quick-reaction process. The controller may periodically cycle the flow rates between the first and second rates for better accuracy and faster verification times.

Abstract: There is disclosed a method of operating a calorimetric gas detector system that comprises a substrate (1) bearing a material (12) that can react with a target gas to produce a change in the wavelength of radiation absorbed or transmitted by the material (“colour-change material”). The method involves: a) applying onto a region (15) of the substrate that includes colour-change material a chemical of predetermined concentration that reacts directly or indirectly with the colour-change material to produce a change in the wavelength of the radiation absorbed or transmitted by the material; b) detecting the radiation absorbed or transmitted in said region (15) at a wavelength absorbed or transmitted by the reaction product of the colour change material with the chemical, and c) generating a signal in accordance with the amount of radiation detected at the second wavelength, said signal being dependent on the amount of colour-change material on the substrate.

Abstract: A method and apparatus for gas detection uses a sensor such as an electrochemical (EC) cell and includes a feedback control loop to control a pump to establish a first predetermined gas flow rate to the EC cell. The concentration of the gas at the first predetermined flow rate is measured. If the detected concentration exceeds a predetermined Alert value at the first flow rate an Initial Warning without remedial action is generated, and, the system then changes the gas flow rate before an Alarm is indicated. An Alarm is signaled only if the system verifies the first measurement. Preferably the first flow rate is set to optimize the measurement accuracy of the EC cell being used, and the second flow rate is lower than the first. Verification of an Alarm at the first flow rate may be conducted quickly by a quick-reaction process. The controller may periodically cycle the flow rates between the first and second rates for better accuracy and faster verification times.

Abstract: A method and apparatus for gas detection uses a sensor such as an electrochemical (EC) cell and includes a feedback control loop to control a pump to establish a first predetermined gas flow rate to the EC cell. The concentration of the gas at the first predetermined flow rate is measured. If the detected concentration exceeds a predetermined Alert value at the first flow rate an Initial Warning without remedial action is generated, and, the system then changes the gas flow rate before an Alarm is indicated. An Alarm is signaled only if the system verifies the first measurement. Preferably the first flow rate is set to optimize the measurement accuracy of the EC cell being used, and the second flow rate is lower than the first. Verification of an Alarm at the first flow rate may be conducted quickly by a quick-reaction process. The controller may periodically cycle the flow rates between the first and second rates for better accuracy and faster verification times.

Abstract: A method and apparatus for gas detection uses a sensor such as an electrochemical (EC) cell and includes a feedback control loop to control a pump to establish a first predetermined gas flow rate to the EC cell. The concentration of the gas at the first predetermined flow rate is measured. If the detected concentration exceeds a predetermined Alert value at the first flow rate an Initial Warning without remedial action is generated, and, the system then changes the gas flow rate before an Alarm is indicated. An Alarm is signaled only if the system verifies the first measurement. Preferably the first flow rate is set to optimize the measurement accuracy of the EC cell being used, and the second flow rate is lower than the first. Verification of an Alarm at the first flow rate may be conducted quickly by a quick-reaction process. The controller may periodically cycle the flow rates between the first and second rates for better accuracy and faster verification times.

Abstract: Methods for treating cancer are provided that involve administration of a combination of the chemotherapeutic drug, temozolamide, and thymidine.

Abstract: A gas sensor including a housing containing at least a sensing electrode, a counter electrode, a test electrode, and electrolyte means in contact with such electrodes. The housing permits gas from the environment to flow to the sensing electrode. The gas sensor is operable either in a normal mode of operation in which potentials are applied to the electrodes for detecting when a gas to be sensed is present at the sensing electrode, or in a test mode of operation in which potentials are applied to the electrodes so that the test electrode generates a gas which flows to the sensing electrode to enable an indication whether the sensor is operating correctly.

Abstract: Methods for treating cancer are provided that involve administration of a combination of the chemotherapeutic drug, temozolamide, and thymidine.

Abstract: The present invention provides an improved whole body hyperthermia apparatus for raising the body temperature of a patient, said apparatus emitting radiant heat from a surface heated by a fluid. The present invention also provides an improved method for treating a cancer patient, said method comprising administering an anti-neoplastic agent to the cancer patient undergoing whole body hyperthermia under less stressful and more effective conditions with the improved whole body hyperthermia apparatus.

Abstract: A method of making an electrical connection of a conductor (1) to a thick film track (2) mounted on a substrate (3) includes the steps of heating the conductor (1) to a temperature at which it may melt the glass constituent of the track (2), and inserting it into the track (2) such that it sinks in and contacts the metallic constituent of the track. The glass sets, fixing the conductor in place. Thus the need for a second firing operation is avoided.

Abstract: An ammonia gas sensor 16 is housed within a container 14 partially immersed in a solution 2 containing ammonium ions. An electrochemical generator 6, 8, 10 generates hydroxyl ions in a region of the solution 2 adjacent the container 14. This converts ammonium ions to ammonia gas which is sensed by the sensor 16 having passed through a gas-permeable member 12. This sensing provides an indication of the concentration of ammonium ions in the solution 2.

Abstract: Improved methods of selectively localizing, imaging and/or treating tumors, which have a net negative charge, employ novel compositions containing non-immunogenic complexes having a net positive charge in a sterile solution. The complexes contain polylysine, a linking agent bound to less than all of the lysyl groups of the polylysine, and an imaging agent or a chemotherapeutic agent which is also bound to the linking agent.

Abstract: A gas sensitive device, for example a gas sensitive MISFET (FIGS. 1 to 3) has a gas-sensitive electrode (15) comprising a catalytically active metal (e.g. Pt or Pd) and a non-metallic material (e.g. SiO.sub.2) mixed with, or deposited at an exposed surface of, the metal to modify the catalytic activity of the metal. The electrode has an enhanced sensitivity to, and selectivity of, certain gases. The composite material is applicable to other gas-sensitive devices, e.g. an optical fibre gas sensor.

Abstract: An ammonia gas sensor comprises a dual gate field effect transistor (FET) in which the two gate electrodes are of platinum deposited respectively by sputtering and evaporation. The gate regions of the two FETs are connected together differentially and the net drain source voltage represents the concentration of ammonia gas to which the sensor is exposed.