Abstract: A method for characterizing a sample comprising the steps of depositing the sample on a substrate, measuring a first change in optical response of the sample, changing the lateral strain of the sample, measuring a second change in optical response of the sample, comparing the second change in optical response of with the first change in optical response and associating a difference between the second change and the first change in optical response with a property of interest in the sample. The measurement of the first change in optical response is made with the sample having an initial lateral strain. The measurement of the second change in optical response is made after the lateral strain in the sample is changed from the initial lateral strain to a different lateral strain. The second change in optical response is compared to the first change in optical response to find the difference between the second change and the first change.

Abstract: A method for characterizing a sample includes the steps of (a) providing a semiconductor material; (b) applying at least one of an electric field, a pulsed or cw light source, a change in temperature and/or a change in pump pulse intensity to the semiconductor material; (c) absorbing pump light pulses in a portion of the semiconductor material and measuring changes in optical constants as indicated by probe light pulses applied at some time t following the absorption of the pump light pulses; and (e) associating a measured change in the optical constants with at least one of a surface charge, dopant concentration, trap density, or minority carrier lifetime.

Abstract: Two or more hydrophilic polymers that are not soluble in each other at a particular concentration and temperature, but which have a positive spreading coefficient in solution, are used to form multi-layered polymeric microspheres. The multi-layer microspheres produced by the method are distinguished by extremely uniform dimensioned polymer layers and actual incorporation of a substance to be delivered into the polymer layers. In the preferred embodiment of the method, two polymers are dissolved in an aqueous solvent, the substance to be incorporated is dispersed or dissolved in the polymer solution, the mixture is suspended in an organic solvent or polymer/water mixture and stirred, and the solvent is slowly evaporated, creating microspheres with an inner core formed by one polymer and an outer layer formed by the second polymer.

Abstract: Methods and compositions are provided for enhancing the bioadhesive properties of polymers used in drug delivery devices. The bioadhesive properties of a polymer are enhanced by incorporating a metal compound into the polymer to enhance the ability of the polymer to adhere to a tissue surface such as a mucosal membrane. Metal compounds which enhance the bioadhesive properties of a polymer include water-insoluble metal compounds such as water-insoluble metal oxides, including oxides of calcium, iron, copper and zinc. The metal compounds can be incorporated within a wide range of polymers including proteins, polysaccharides and synthetic biocompatible polymers. In one embodiment, metal oxides can be incorporated within polymers used to form or coat drug delivery devices, such as microspheres, which contain a drug or diagnostic agent.

Abstract: Disclosed is a system for the characterization of thin films and interfaces between thin films through measurements of their mechanical and thermal properties. In the system light is absorbed in a thin film or in a structure made up of several thin films, and the change in optical transmission or reflection is measured and analyzed. The change in reflection or transmission is used to give information about the ultrasonic waves that are produced in the structure. The information that is obtained from the use of the measurement methods and apparatus of this invention can include: (a) a determination of the thickness of thin films with a speed and accuracy that is improved compared to earlier methods; (b) a determination of the thermal, elastic, and optical properties of thin films; (c) a determination of the stress in thin films; and (d) a characterization of the properties of interfaces, including the presence of roughness and defects.

Abstract: Methods and compositions are provided for enhancing the bioadhesive properties of polymers used in drug delivery systems. The bioadhesive properties of a polymer are enhanced by incorporating an anhydride oligomer into the polymer to enhance the ability of the polymer to adhere to a tissue surface such as a mucosal membrane. Anhydride oligomers which enhance the bioadhesive properties of a polymer include oligomers synthesized from dicarboxylic acid monomers, preferably those found in Krebs glycolysis cycle, especially fumaric acid. The oligomers can be incorporated within a wide range of polymers including proteins, polysaccharides and synthetic biocompatible polymers. In one embodiment, anhydride oligomers can be incorporated within polymers used to form or coat drug delivery systems, such as microspheres, which contain a drug or diagnostic agent. The oligomers can either be solubilized and blended with the polymer before manufacture or else used as a coating with polymers over existing systems.

Abstract: Microporous macrocapsules are disclosed which are useful as implantation devices for cell therapy. The macrocapsule comprises living cells that secrete biological substance that are therapeutically useful and that are released from the macrocapsule to the site of implantation. The capsules can have selected permeability characteristics based upon their particular usage and desired viral retentivity characteristics.

Abstract: A gain medium is comprised of a multi-phase system wherein: a first phase is an electromagnetic radiation emission phase; a second phase is an electromagnetic radiation scattering phase; and a third phase is a transparent matrix phase. By example, the emission phase may consist of dye molecules, the scattering phase may consist of high contrast particles, and the matrix phase may consist of a solvent such as methanol. In some embodiments of this invention the emission and scattering phases may be the same phase, as when semiconductor particles are employed. A smallest dimension of a body comprised of the gain medium may be less than a scattering length associated with the scattering phase. It is shown that nearly thresholdless laser behavior is observed in strongly scattering optically pumped dye-methanol solutions containing colloidal TiO.sub.2 or Al.sub.2 O.sub.3 ruby nanoparticles.

Abstract: A sealed, implantable, encapsulation device (20) for diffusing a biologically active product or function to an individual which includes a substantially non-porous fitting (32) including an inner surface (33) defining an access port (34). A permselective, porous, membrane (21), having an interior surface (22), cooperates with the fitting inner surface (33) to form a storage cavity (23) therebetween. The membrane interior surface (22) is in substantially cell-tight dry sealing engagement with fitting (32) to seal cavity (23). Living cells (24) are disposed in the cavity (23) which are capable of secreting the biologically active product to an individual. The membrane (21) is of a material capable of permitting the passage of substances between the individual and cells required to provide the biological product or function. A plug member (35) is positioned in the access port (34) and seated in cell-tight sealing engagement with the fitting inner surface (33).

Abstract: Two-photon excitation of charge carriers in boron E'-center containing borosilicate glasses is shown to result in a photo-encoding of selectively etchable regions. Using a turbulent process followed by polishing, a number of patterning capabilities for microtechnology applications are achieved, such as ultra-fast capillary electrophoresis chips and rapid prototyping of diffractive optical elements.

Abstract: This invention teaches a method for authenticating a document. The method includes the steps of: (a) providing a document to be authenticated; (b) illuminating at least a portion of the document with laser light that exceeds a threshold fluence; (c) detecting a narrow band laser-like emission of at least one wavelength from the document in response to the step of illuminating; and (d) declaring the document to be authentic only if the laser-like emission is detected.

Abstract: A method is disclosed for sorting textiles, as is a system that operates in accordance with the method. The method includes steps of (a) providing a plurality of textiles to be sorted, each of the textiles comprising a portion that includes an electromagnetic radiation emitting and amplifying material; for each textile, (b) illuminating at least the portion with laser light that exceeds a threshold fluence; (c) detecting a narrow band laser-like emission of at least one wavelength from the portion in response to the step of illuminating; and (d) sorting the textiles based on the detected laser-like emission. In one embodiment the textile has at least one stitched-in thread, the thread comprising a substrate material and the electromagnetic radiation emitting and amplifying material in combination with scatterers for providing the laser-like emission. In another embodiment the textile has an applied patch containing the electromagnetic radiation emitting and amplifying material.

Abstract: A method of forming an implantable and retrievable immunoisolatory vehicles is disclosed, the method comprising the steps of first forming a core comprising a volume of at least 1 .mu.l and at least 10.sup.4 cells capable of providing a biologically active product or metabolic or immunologic function, said cells being dispersed in a biocompatible hydrogel or extracellular matrix, and then forming around the core a surrounding external biocompatible thermoplastic or hydrogel jacket free of said cells projecting externally thereof, said jacket having molecular weight cutoff permitting passage of molecules to and from the core through said jacket to provide said biologically active product or function.

Abstract: Methods are disclosed for the alleviation of movement disorders via the implantation of static devices which focally release neuroinhibitory compounds to preselected brain areas. Pathological conditions to be treated by these methods include parkinsonian movement disorders, Huntington's chorea, and epileptiform seizure activity. In the treatment of parkinsonism, target areas implantation include the subthalamic nucleus, the globus pallidus internus, and the substantia nigra pars reticulata. In the treatment of epilepsy, implants may be placed in an epileptogenic focus area of neural over-activity. The devices may be polymeric implants that release neuroinhibitory compounds such as GABA, GABA agonists, GABA potentiators, action potential blockers and voltage dependent calcium channel blockers, and glutamate antagonists. Alternatively, the devices may contain living cells which secrete neuroinhibitory compounds.

Abstract: Vehicles containing cells for implanting in the tissue of an individual are prepared having cells dispersed in a particulate, essentially non cross-linked chitosan core matrix that is enclosed within a semipermeable membrane. The cells are entrapped between chitosan particles of the core matrix and there is essentially no interfacial cross-linking between the core matrix and the membrane. The core matrix provides a physical support for viable cells within the vehicle such that the cells are evenly dispersed throughout the core matrix so as to allow their maintenance, growth, proliferation and differentiation. The vehicle can be prepared by mixing viable cells with a solution of chitosan, encapsulating the resultant mixture in a semipermeable membrane and causing the chitosan to precipitate such as by changing the pH to form the core matrix. Alternatively, the chitosan is precipitated to form the core matrix containing cells and then the core matrix is encapsulated in a semipermeable membrane.

Abstract: A method for treatment of a neurodegenerative condition in a patient comprising implanting in the patient at least one immunoisolatory vehicle comprising a corc comprising a volume of at least 1 .mu.l and at least 10.sup.4 living cells which secrete at least one biologically active product, said cells being dispersed in a biocompatible matrix comprising a hydrogel or extracellular matrix components, and an external jacket surrounding the core, the jacket comprising a biocompatible hydrogel or thermoplastic, the jacket being free of cells projecting externally thereof, said jacket having a molecular weight cutoff permitting the passage of the biologically active product from the core through the jacket.

Abstract: A method for treating diabetes in a patient comprising subcutaneously implanting in the patient at least one immunoisolatory vehicle comprising a core comprising a volume of at least 1 .mu.l and at least about 10.sup.4 living cells which secrete insulin, said cells being dispersed in a biocompatible matrix comprising a hydrogel or extracellular matrix components, and a surrounding external jacket of a biocompatible thermoplastic or hydrogel free of said cells projecting externally thereof, said jacket being permselective and immunoisolatory, said jacket having a molecular weight cutoff permitting passage of molecules between the patient and core through said jacket wherein the insulin is released from the immunoisolatory vehicle into the patient's body to treat diabetes.

Abstract: A user can selectively replay portions of a computer program execution, so that the entire program need not be run again to support further test and debug. A run-time instrumented version of the program is created by inserting special instructions into the original program. The run-time instrumented version is executed to create trace files of memory accesses and system calls, as well as identification of interrupts. During execution of the run-time instrumented version, a state of each accessed memory location is monitored and updated to determine which memory accesses should be traced and when. This monitoring and updating is performed in a manner which minimizes interference with the execution. A user then may select a desired portion of the original computer program for replay and, in response, appropriate data is stored in corresponding memory locations so that the desired portion of the program may be replayed accurately.

Abstract: A method and optical system is disclosed for measuring an amount of stress in a film layer disposed over a substrate. The method includes steps of: (A) applying a sequence of optical pump pulses to the film layer, individual ones of said optical pump pulses inducing a propagating strain pulse in the film layer, and for each of the optical pump pulses, applying at least one optical probe pulse, the optical probe pulses being applied with different time delays after the application of the corresponding optical probe pulses; (B) detecting variations in an intensity of a reflection of portions of the optical probe pulses, the variations being due at least in part to the propagation of the strain pulse in the film layer; (C) determining, from the detected intensity variations, a sound velocity in the film layer; and (D) calculating, using the determined sound velocity, the amount of stress in the film layer.

Abstract: Disclosed is a method for characterizing a sample, comprising the steps of: (a) acquiring data from the sample using at least one probe beam wavelength to measure, for times less than a few nanoseconds, a change in the reflectivity of the sample induced by a pump beam; (b) analyzing the data to determine at least one material property by comparing a background signal component of the data with data obtained for a similar delay time range from one or more samples prepared under conditions known to give rise to certain physical and chemical material properties; and (c) analyzing a component of the measured time dependent reflectivity caused by ultrasonic waves generated by the pump beam using the at least one determined material property. The first step of analyzing may include a step of interpolating between reference samples to obtain an intermediate set of material properties. The material properties may include sound velocity, density, and optical constants.