摘要:
A process for producing microcapsules of controlled porosity containing a chemically active core material. A core material such as a biologically active material and a first monomer in aqueous solution are emulsified in a hydrophobic solvent. A monomer complementary to the first and soluble in the continuous, hydrophobic phase of the emulsion is added to initiate interfacial polymerization about the aqueous droplets. During the course of the reaction, the affinity of the continuous phase for the first monomer is varied by adding a solvent to the continuous phase to vary its polarity. The continuous phase may be relatively nonpolar at the outset and a polar solvent may be added to increase its affinity for the first monomer, or it may be relatively polar at the outset and a nonpolar (or less polar) solvent may be added. This technique allows production of microcapsules having a selected pore size so that, for example, encapsulated material cannot escape, yet lower molecular weight materials can diffuse through the capsule wall.
摘要:
A chemical analyzer in which the measurement of the change in attenuation of RF radiation propagated through a sample is used as the basis for calculating the change in concentration of a given chemical in the sample. Also disclosed are various probe and system designs which facilitate the use of RF attenuation as a basis for measurement of certain chemical characteristics of a sample.
摘要:
Techniques for producing semipermeable microcapsules by interfacial polymerization are disclosed. The material to be encapsulated and a hydrophilic monomer are emulsified within a hydrophobic continuous phase. Polymerization is initiated by dissolving a second monomer in the continuous phase, and occurs only at the interface of the emulsion to result in the formation of macroporous, poorly defined capsule membranes. Next, the affinity of the continuous phase for the hydrophilic monomer is varied by altering the polarity of the continuous phase. This step is accomplished either by isolating and resuspending the raw capsules in a fresh continuous phase of different polar character, or by mixing a second solvent with the continuous phase. By controlling the affinity and the concentration of the second monomer, it is possible to produce microcapsules having uniform capsule membranes and a selected upper limit of permeability.
摘要:
A control panel includes a first switch to effect selective actuation of a garage door opener motor, with a second on/off switch arranged to effect selective locking engagement and disengagement of the motor relative to the first switch. An indicator light is arranged to indicate separation of a garage door from a garage door framework. An abutment switch is arranged also for engagement with a vehicular windshield for actuation of the garage door motor.
摘要:
Disclosed is a process for encapsulating oils and oil-soluble substances in multi-compartmentalized, mechanically stable microcapsules. The process comprises the steps of first forming an emulsion consisting of a continuous phase comprising an aqueous solution of an alkali metal alginate and optionally a water-soluble, alcohol-insoluble filler such as a polysaccharide, and a dispersed phase of an oleophilic substance such as one or more vitamins dissolved in an oil. The emulsion is then formed into droplets which are thereafter immersed in an alcoholic solution of multivalent cations, to produce a shape-retaining alginate matrix filled with precipitated polysaccharide and enclosing plural oil droplets. The vitamins are thereby protected from oxidative degradation and can be handled like conventional crystalline solids.
摘要:
A process for determining an immunogenic substance present in a sample wherein the immunogenic substance in the sample competes with a distinguishable analog of such substance for available binding sites on an antibody which is highly specific for the immunogenic substance in the sample. The antibody is encapsulated in a semi-permeable microcapsule.A specific example of the foregoing procedure is the determination of digoxin present in serum wherein the digoxin in the serum competes with radioiodine labeled digoxin for available binding sites on an antibody which is highly specific for digoxin and has been previously encapsulated in semi-permeable microcapsules. The concentration of digoxin in the sample is determined from a standard curve by relating digoxin concentration inversely to the percent of radioiodine labeled digoxin that is complexed to the antibody.
摘要:
A flexible hat or cap-like assembly having a compressible doughnut shape memory substance or padding disposed within and is worn on a person's head for cushioning an object or load such as sheetrock which is carried or supported on the head during drywall installation of a ceiling. The doughnut style padding places the pivot area of the object off the crown of the person's head and places the pivot area around the outer parameter of the head. This increases the pivot area of the load to equal the circumference of the compressible substance. The larger pivot area increases balance and stability of the load and reduces side loading and thrust on the person's neck which is associated with prior art devices having a centralized load pivot point.
摘要:
A system and device for insuring the integrity of an automatic garage door has a sensor to determine the status of the door with respect to a predetermined position and a programable actuator which provides a positive signal for automatically activating a warning or alert system when the door is in predetermined position when the programmable actuator is activated and the sensor indicates that the door is at other than the predetermined position. Preferably the programmable actuator is a timer and the predetermined position is closed. The timer can be remotely programmable. The actuator can also be triggered by a sensor of an event such as darkness. Remote means are provided for manually activating the door to return to the desired position by an RF frequency transmitter.
摘要:
Efficient mixing is promoted in a turbulent stirring unit by providing an agitator with flexible finger-like appendages and by varying the rate of rotation of a rotating magnetic field such that the fingers execute an undulatory motion, disrupting laminar flow and tending to collapse the liquid vortex. Motor control for controlling the fluctuation of the rotating magnetic field may provided by simple and economical electronic or electromechanical means. The control unit may be separately configured to control a number of other pieces of equipment, either in common or independently. The controller also may be integrated into stirrers, vortexers or shaker tables or externally provided to control existing units.
摘要:
A two step interfacial polymerization process for encapsulating operative chemically active substances in high quality semipermeable membranes. An emulsion is formed wherein the discontinuous phase contains the substance to be encapsulated and a first monomer. When a second monomer is added to the continuous phase, an imperfect membrane forms about the droplets of the discontinuous phase. Removal of the continuous phase, followed by resuspension of the raw microcapsules and addition of a second portion of second monomer, causes further polymerization strengthening the membranes and "patching" macroporous defects in them. The choice of solvents and control of reaction conditions such as pH, maximize the yield of operable labile substance encapsulated. A method of encapsulating a very high concentration of hemoglobin is also disclosed. Adaption of the two step process provides a method for forming and controlling the pore sizes in the membranes of a number of known prior art encapsulation processes.