Abstract: A direct drive system for a high speed ultracentrifuge. The drive spindle assembly is removable through the rotor chamber without disturbing any vacuum seals that are present to isolate the requisite vacuum environment in the rotor chamber for high speed rotation. All of the high speed bearings are connected to the spindle assembly for removal as a unit. An induction motor provides the direct drive with the motor armature mounted on the drive spindle assembly.

Abstract: Pipetting and diluting apparatus including an interchangeable syringe pump of predetermined volume capacity and a stepper motor for driving the syringe piston at a selected speed for dosing a selected volume of fluid. The piston stroke is calculated from the syringe volume capacity and the volume of fluid to be dosed. Control means controls the acceleration and deceleration characteristic of the piston in accordance with an exponential function dependent upon the selected piston speed and the syringe volume capacity.

Abstract: An improved electroencephalograph system is disclosed having a system for automatically verifying the input and output parameters of the various channels, the preset number selected, and a patient identification number. A coded output is used employing the standard EEG pen recorder outputs. Numerical sequences such as the preset number and a patient identification number are displayed on a single event marker channel as modified Roman numeral sequence of digits directly readable by the operator.

Abstract: A short path liquid junction structure is defined through a porous ceramic layer coated circumferentially on an electrochemical electrode glass body by an elastomeric O-ring sealing member circumferentially engaging the ceramic layer in an annular line contact seal. The length of the liquid junction path is the short distance through the porous ceramic layer around and past the line contact seal.

Abstract: Apparatus for conveying a blood sample through a flow cell which measures characteristics such as pH, PCO.sub.2, and PO.sub.2 of the sample and for pumping a wash solution through the cell between samples. The flow cell inlet is selectively connected (1) to a sample-filled syringe for driving sample through the flow cell or (2) to a reservoir of the wash solution. The flow cell outlet is connected by a conduit to a waste receptacle. A rotor of a combined peristaltic pump and valve coacts with an elastomeric tubular section of the conduit. The rotor and the elastomeric section are movable in a transverse direction relative to each other between (1) a first or pumping position wherein the rotor compressively engages the section for pumping fluid wash solution through the cell and the conduit and (2) a second or relaxed position wherein the rotor is released from the section to provide an open unrestricted channel for the flow of sample driven by the syringe through the cell.

Abstract: An ink priming system for a multi-pen recorder of the gravity-fed capillary tube type comprises a gas manifold common to all of the ink bottles individually provided for each channel of the recorder. Individual control valves may be selectively actuated by the operator to prime each pen. When the control valve is closed, the gas pressure is bled off so that the inking system thereafter acts as a normal gravity-fed capillary tube system. A non-clogging inking system is provided by utilizing a short length of flexible thin walled tubing to supply ink to the movable recording pen. The length of this tubing is sufficiently short that evaporation of the ink solvent through the walls of the tube is accompanied by diffusion of the dye back to the ink bottle so that the concentration of dye in the ink at the end of the tube adjacent the recording pen does not exceed saturation value during prolonged periods of non-use of the recorder.

Abstract: A synthetic pentapeptide of opiate agonist activity having the formula H-Tyr-Gly-Gly-Phe-Met-NH.sub.2 formed in a solid-state method.

Abstract: Ambient or low-temperature curable solutions or aqueous dispersions of (1) a polymer containing units polymerized from a monomer mixture of (a) from about 0.25% to about 30% by weight of a polymerizable aldehyde, and (b) at least one copolymerizable mono-ethylenically unsaturated monomer, with (2) a curing agent selected from the group of dicarboxylic acid bis-hydrazides, dicarboxylic acid bis-hydrazones, and acrylic oligomers and low molecular weight acrylic solution polymers containing a plurality of pendant hydrazide or hydrazone groups. The solutions or dispersions are useful as general industrial coatings, maintenance coatings, furniture and appliance coatings, heavy transportation coatings, automobile refinishes and plastics coatings.

Abstract: A reagent, of the type comprising a precipitator capable of precipitating low density lipoproteins, very low density lipoproteins, and other non-high density lipoproteins, is improved by the addition thereto of a non-interfering suitable agent capable of enhancing the flocculation of a precipitant formed by the precipitator and the various non-high density lipoprotein fractions in highly lipemic serum.

Abstract: Fluorescent displays are comprised of a means for cooperatively aligning a liquid crystal material and a fluorescent medium disposed therein. The fluorescent medium is comprised of a nematic liquid crystal host which is effectively transparent to radiation of both near ultraviolet and visible wavelengths and a fluorescent guest whose visible fluorescent intensity varies with the phase or orientation of the liquid crystal host.

Abstract: Powder compositions useful for making conductors, e.g. microcircuit conductors, end terminations for capacitors, electrodes for gas discharge display devices, etc. The compositions comprise inorganic powders dispersed in an inert vehicle and are printed and fired in the conventional manner on dielectric substrates. The inorganic powders comprise aluminum, silicon, and glass.

Abstract: A method of determining the need for post-addition of antigen or antibody to an antigen-antibody reaction to ascertain whether the reaction is in an antigen excess or an antibody excess condition. The time rate of change of a nephelometric signal developed from the reaction is monitored to generate a rate signal having a peak value providing a measure of antigen concentration. The post-addition step is performed only if the peak rate value is ambiguous--, i.e. if it indicates one antigen concentration value for a reaction in antigen excess but another value for a reaction in antibody excess. The need for the post-addition step is determined from measured qualities of the rate signal including one or more of (1) the peak rate value, (2) the elapsed time from the start of the reaction to the peak rate, and (3) the product of the peak rate and the elapsed time. When required, the post-addition step may be performed during progress of the antigen-antibody reaction after measurement of the peak rate value.

Abstract: A multi-channel instrumentation system is provided wherein signals from selected electrode pairs are sequentially connected to the isolated input of a common signal amplifying path. The electrode pair selecting means is included in a portable head box which may be placed adjacent to the patient to be tested. Included in the head box are facilities for testing the impedance of any selected one of the patient electrodes and providing a visual indication of the magnitude of such impedance. The head box also includes facilities for selecting a group of patient electrodes which are connected together and used as an average or reference potential for one input of the common signal path. Facilities are also provided for calibrating the common signal path by applying a d.c. calibration signal to the input thereof by means isolated from system ground.

Abstract: A multi-channel instrumentation system is provided wherein signals from selected electrode pairs are sequentially connected to the isolated input of a common signal amplifying path. The electrode pair selecting means is included in a portable head box which may be placed adjacent to the patient to be tested. Included in the head box are facilities for testing the impedance of any selected one of the patient electrodes and providing a visual indication of the magnitude of such impedance. The head box also includes facilities for selecting a group of patient electrodes which are connected together and used as an average or reference potential for one input of the common signal path. Facilities are also provided for calibrating the common signal path by applying a d.c. calibration signal to the input thereof by means isolated from sytem ground.

Abstract: A stable blood serum bilirubin reference composition characterized in that said composition either (1) possesses a pH of from about 8.3 to about 9.5 or (2) further comprises a sulfhydryl compound in an amount sufficient to enhance the stability of the bilirubin or (3) both possesses a pH of from about 8.3 to about 9.5 and further comprises a sulfhydryl compound in an amount to further enhance the stability of the bilirubin.

Abstract: A vacuum operated system for transferring fluid from a container to an open or relatively large sump without applying vacuum to the sump. A small, closed, intermediate chamber is interposed in a flow path between the container and the sump. Vacuum from a small vacuum source is applied to the intermediate chamber and draws fluid from the container through a first conduit into the chamber. A peristaltic pump draws fluid from the chamber through a second conduit to the sump while maintaining a vacuum seal for the chamber preventing loss of vacuum through the second conduit.

Abstract: A device for the sequential fractionation of the contents of a centrifuge tube containing centrifugally separated contents utilizing a syringe-like apparatus. The present invention utilizes removable syringe tips that are mounted on a chamber housing for extraction and retention of a precise volume of centrifuged fluid from the centrifuge tube. The syringe-like apparatus is mounted to a frame in such a manner that the chamber housing is movable relative to the plunger or piston to permit precise movement of the chamber housing with the removable syringe tip into the centrifuge tube for delicate and precise removal of the desired fraction of the fluid. The syringe tips are removed with each fraction that is collected from the contents in the centrifuge tube and can be placed in a storage rack for subsequent analysis.

Abstract: A double beam, optical null spectrophotometer including means for automatically determining system loop gain requirements and setting the gain to the correct value for optimum response under all operating conditions. With the system ready for operation and a sample in the sample beam path, a difference signal is generated as a function of the position of a reference beam attenuator with and without a small unbalancing signal applied to the system loop. This difference signal is compared to a desired difference signal and a loop gain adjustment is made so that the difference signal will equal the desired difference signal, thereby establishing instrument gain for optimum response.

Abstract: An apparatus and method to isolate faults in a catalytic converter equipped internal combustion engine.The exhaust is analyzed to determine hydrocarbon content, carbon monoxide content and oxygen content and this data is processed through an electronic circuit which accumulates information to be disclosed at the termination of testing.

Abstract: Apparatus compensating for "aperturing effects" produced when a sample holding aperture is incorporated in the sample beam of a conventional dual beam spectrophotometer to allow examination of very small size samples. Such effects usually take the form of undesired variations in the base line output of the spectrophotometer at wavelengths where the spectrophotometer slits open wider than the sample aperture in an attempt to produce a constant energy scan over a given spectrum. The apparatus comprises a second aperture optically equivalent to the sample aperture and located at a slit image point in a common beam portion of the spectrophotometer.