Abstract: Screening tests and bioassay of von Willebrand's factor (platelet aggregating factor) in human and animal blood plasma are effected using a reagent of blood platelets and snake venom having a positive platelet aggregating cofactor effect. The reagent and tests may also suitably employ dried blood platelets. The reagent may comprise dried platelets and either ristocetin or active snake venom as the platelet aggregating cofactor.

Abstract: Disclosed is an electrochromic variable light modulating device including an improved ion conducting medium comprising a solid or semi-solid layer of polymer of the ion exchange type wetted with a small amount of water and/or acid electrolyte solution.

Abstract: A system for detecting thermal breakdown of organic resin coatings is described which can be used for locating failure occurring in electrical apparatus based on the use of a minor amount of a chemical tagging material. The chemical tag can be readily extracted from particulate generated by the thermal breakdown of the organic resin coating by extracting the particulate with an organic solvent and analyzing the extract in a gas chromatograph using an electron capture detector. Useful results have been found when employing certain halogenated aromatic organic compounds, such as N-alkyl tetrahalophthalimides, which can be employed in the particulating resin at concentrations of as little as 0.01% by weight.

Abstract: Liquid crystal mixtures having positive anisotropy of the dielectric constants comprising a nematogenic material having a clearing point above 60.degree. C., one or more compounds of the formula ##STR1## wherein R.sub.1 and R.sub.2 are hydrogen or straight-chain alkyl, provided that at least one of R.sub.1 and R.sub.2 is other than hydrogen and that R.sub.1 and R.sub.2 together contain no more than 9 carbon atoms,and, if desired, one or more additional doping agents, are described.

Abstract: A photographic flash device comprising a first mechanism for varying the angle of divergence of a flashed light and a second mechanism for varying the direction of the flashed light. The first variable mechanism is provided with a first body having a light source, a second body, a first slidable molding which has an optical panel to cover the front of the light source, a second slidable molding which surrounds the first slidable molding, and detent means which control slide movement of the first slidable molding and connects the first slidable molding with the first body. The second variable mechanism changes the direction of the flashed light from the light source by rotatably connecting the moldings to an additional body.

Abstract: A modular housing assembly for housing a vehicle warning light system and intended for mounting across the roof of a police car or other vehicle on which warning lights are required. The housing comprises a plurality of transparent plastic panels of modular construction, there being provided a plurality of front modular panel sections interconnected in side-by-side relation and a plurality of rear modular panel sections interconnected in side-by-side relation, the front and rear panel sections being connected to one another and to a common base member.

Abstract: An improved method of storing and shipping a blood serum reference composition comprising in its non-biological component from about 40 to about 85 weight percent water, from about 15 to about 60 weight percent of at least one alkylene polyol having from 2-5 carbon atoms, the remainder being chiefly at least one natural biological material selected from a group consisting of blood serum, enzyme, metabolites, electrolytes, and hormones. The improvement comprises storing and/or shipping the composition at a temperature below the freezing point thereof.

Abstract: A compound is disclosed herein which is water soluble and is useful in assay procedures for measuring serum cholesterol. In one embodiment, the compound comprises a cholesterol ester having the general formula R.sub.1 -R.sub.2 -[Cholesterol Base], in which R.sub.1 is a water soluble, nonionic surfactant and R.sub.2 is a dicarboxyl group bonded by ester linkages to R.sub.1 and to the cholesterol. In an alternate embodiment the compound comprises a pregnenolone derivative having the general formula R.sub.3 -[Pregnenolone Base]-R.sub.4. A compound in accordance with the present invention is useful by itself or in combination with blood serum as a standard or reference material for cholesterol assay procedures.

Abstract: A fisherman's appliance to aid in attracting fish to a baited fish hook or artificial lure having a pair of spaced non-transparent circular plates between which is disposed an electric lamp bulb for directly illuminating surrounding water in which the appliance is suspended radially and horizontally outwardly from the appliance and in a relatively narrow vertical beam above and below the level of the appliance in the water.

Abstract: A lamp for use in subterranean galleries such as mines in which the cold-cathode discharge tube is received in a housing which, in turn, is removably mounted in a receptacle and is held in place by a ring clamping a flange of the housing against a flange of the receptacle. The housing may be provided with a translucent cover so that the housing can be removed and replaced as a unit. A reed switch on the receptacle cooperates with a magnet on the housing to deenergize the terminals of the housing upon its removal. The terminals of the discharge tube are embedded in an insulating potting mass within the housing.

Abstract: Novel liquid crystal dyestuffs of the formula ##STR1## wherein Y and Z are different and can be nitro or cyano and --N(R).sub.2 wherein R is alkyl or alkylene, preferably of 1 to 4 carbon atoms, and X can be hydrogen, methyl, fluoro or chloro, can be added to known liquid crystal compositions to impart color to the mixtures and improve contrast in a liquid crystal electro-optic device containing such mixtures.

Abstract: A porous, hydrophilic, assimilable prosthesis is formed by the removal of solvent, without substantial dimensional change, from a solution of (a), an assimilable polymer composed primarily of polymerized units of an alpha or beta hydroxy carboxylic acid, preferably but not necessarily those having 1 to 4 carbon atoms, and (b), a small amount of a physiologically acceptable wetting agent that is sufficient to impart hydrophilicity to the prosthesis. The preferred assimilable polymer is a polylactic acid. The preferred process for making the prosthesis involves the lyophilization of a solution of polylactic acid having a molecular weight of at least 100,000, weight average, at a concentration of at least 31/2% by weight of the solution of the polylactic acid. A variety of physiologically acceptable wetting agents is useful, a preferred class being the alkali metal soaps of fatty acids or of alkyl aryl sulfonic acids.

Abstract: A portable light having a U-shaped body and an elongated reflector supported on the body providing a space for batteries between the reflector and the body. Two lamps are supported on the reflector providing a flood light and a lens is supported on the body over the reflector and the lamps. Two cup-shaped end caps are supported on the ends of the light and one end cap has a frusto-conical shaped reflector integrally attached to it, and a lens closes the end of the cap having the reflector in it, and a lamp is supported on the reflector under the lens providing a spot light.

Abstract: Liquid crystal mixtures having positive anisotropy of the dielectric constants which comprise a nematogenic mixture with a clearing point above 60.degree. C. which is doped with an organic solvent or solvent mixture with a specific resistance of at least 10.sup.7 Ohm.cm. as well as a dipole moment along the longitudinal axis of the molecule of less than 3.5 Debye, or with a compound of the formula ##STR1## wherein R.sub.14 and R.sub.15 are straight-chain alkyl containing a total of not more than 14 carbon atoms or R.sub.14 is straight-chain alkyl and R.sub.15 is straight-chain alkoxy containing a total of not more than 8 carbon atoms,or a compound of the formula ##STR2## wherein R.sub.16 and R.sub.17 are straight-chain alkyl containing a total of not more than 6 carbon atoms,or a compound of the formula ##STR3## wherein R.sub.16 and R.sub.17 are straight-chain alkyl containing a total of not more than 6 carbon atoms,or mixtures thereof, are described.

Abstract: A device for the controlled continuous administration of an active agent to an environment of use is disclosed. The device comprises a body of erodible agent release rate controlling material containing an agent dispersed therethrough; the rate controlling material is a hydrophobic poly(carboxylic acid) having one ionizable carboxylic hydrogen for each 8 to 12 carbon atoms, which material erodes at a controlled and continuous rate over a prolonged period of time in response to the environment by a process of carboxylic hydrogen ionization, thereby releasing the dispersed agent at a controlled rate over a prolonged period of time.

Abstract: What follows is the description of an improved hydraulic apparatus for the automatic adjustment of the inclination of the headlights of a motor vehicle, the adjustment being a dependent function of the axle load. The apparatus has a level sensor at each axle and each level sensor contains one metering piston and two positioning pistons. The rear axle level sensor is connected via two separate hydraulic lines to the front axle sensor, and the front axle sensor is in turn connected via two separate hydraulic lines to the positioning elements of the headlight housings. The internal construction of the two level sensors is substantially identical and is chosen such that the system is also suitable for manual adjustment.

Abstract: A composition is disclosed of a solution of a resinous carrier and at least two compounds which thermoparticulate at different temperatures between 60.degree. and 200.degree. C. A coating is made by applying the composition to a portion of an electrical apparatus exposed to a gas stream. As the temperature of the coating increases the compounds therein thermoparticulate. The time between which the compounds thermoparticulate indicates the rate of rise of the temperature and analysis of the products of thermoparticulation indicates the location of the coating in the electrical apparatus. Alternatively, the coating can consist of several layers with a thermoparticulating compound in each layer which thermoparticulates at different temperatures.

Abstract: An ink composition is provided which is suitable for use on plastic, bare metal, for example, tinplate or aluminum as well as on such metals having organic coatings applied to surfaces thereof. The inks are suitable for use in contact printers or in jet ink printing techniques and apparatus. The ink compositions are thermotropic, i.e. they change color in the presence of water or steam at elevated temperature and are useful as sterilization or pasteurization indicators. The inks comprise essentially a binder resin component, or mixture of such resin components, an alcohol solvent and a combination of dyes which produce a visible and permanent color change in the presence of water or steam at elevated temperatures.

Abstract: Dichroic liquid crystal compositions for use in displays are mixtures of a liquid crystal host material and at least one of a plurality of dyes each having a plurality of azo (--N.dbd.N--) bonding groups and a high order parameter. The dichroic liquid crystal compositions each provide a contrast ratio on the order of 10:1.

Abstract: A platelet reference control composition comprising goat blood cells shrunken to the size of human platelets.