Abstract: An electro-optical aerosol characterizing system includes a continuous wave laser for generating two beams in the red wavelength range, intersecting a particle stream at slightly spaced apart locations. A pulsed UV laser generates a beam that intersects the particle stream at a third location downstream. Laser energy scattered by each particle as it passes the first two locations, is used to compute aerodynamic sizes and UV laser pulsing times, so that in each case the UV beam irradiates the particle at the downstream location. Particles containing biological materials or other fluorescing components emit fluorescence signals in response to the irradiation. Accordingly, the system provides information about particle composition as well as particle size.

Abstract: A process and apparatus are disclosed for generating object traces representing the movement of objects through a measuring space. The measuring space can be illuminated by a laser or other light source, or alternatively the objects can be self-illuminating. In either event, light from the objects is detected over a finite acquisition time, to generate the object traces. During a predetermined portion of the acquisition time, preferably near the end, one of several parameters that govern the object trace width is altered to increase the width, thereby giving the object trace the form of an arrow or vector. The altered parameter can be the brightness of illumination, the sensitivity of the image detector, or the position or state of system components, in particular the image detector, a lens or other active optical component between the objects and the detector, or an optical component between the light source and the objects.

Abstract: A device and process for interferometric sizing of stochastic (irregular and/or inhomogeneous) particles is disclosed. The device generates a pair of laser beams that interfere with one another to form a measuring volume including interference fringes. Particles crossing the fringes scatter light collected by two or more optical receivers. Outputs of the optical receivers are provided to signal processing and phase processing circuits, to generate indications of particle velocities based on signal frequencies, and indications of particle sizes based on phase shift values. Particles are characterized as to size by generating probability density functions of phase, based on multiple particle traverses through the measuring region, thus to more accurately measure groups of particles, despite the lack of reliability inherent in measuring a single particle. The device is operable in a calibration mode, using particles of known sizes or size distributions.

Abstract: Mutants of human urokinase are produced which have an altered amino acid sequence in the domain responsible for binding of plasminogen activator inhibitor(s). One example of an inhibitor resistant mutant is described in detail. Six amino acids (179-184), R H R G G S, have been deleted from the mature urokinase. The gene encoding inhibitor resistant preprourokinase is chemically synthesized according to computer-designed nucleotide sequences containing convenient restriction endonuclease cleavage sites, a signal for the initiation of translation, a sequence encoding the signal peptide of mouse whey acid protein and a complete coding sequence for mature inhibitor-resistant urokinase. The gene was used to transform cultured mouse cells to produce clones that stably incorporate the gene in the genome. Clones with high levels of expression were used as the hosts for production of this protein.