摘要:
The present invention relates to genetic containment systems which express a biotin-binding component that can be used for selectively destroying recombinant cells such as genetically engineered microorganisms. These systems may comprise a streptavidin or an avidin gene whose expression is controlled by a regulatable promoter. The regulatory agent such as a transcriptional effector is expressed from another gene which may also be expressed and its expression controlled by the containment system. Expression of the agent can be designed to respond to physiological changes in the environment. The invention also relates to containment systems and methods for the selective detection or tracking of recombinant cells and to eukaryotic and prokaryotic cells which contain these genetic containment systems.
摘要:
The present invention relates to genetic containment systems which express a biotin-binding component that can be used for selectively destroying recombinant cells such as genetically engineered microorganisms. These systems may comprise a streptavidin or an avidin gene whose expression is controlled by a regulatable promoter. The regulatory agent such as a transcriptional effector is expressed from another gene which may also be expressed and its expression controlled by the containment system. Expression of the agent can be designed to respond to physiological changes in the environment. The invention also relates to containment systems and methods for the selective detection or tracking of recombinant cells and to eukaryotic and prokaryotic cells which contain these genetic containment systems.
摘要:
Langmuir-Blodgett films having photo-electronic properties and methods of making the same. The instant films may be made, for example, by spreading a mixture of one or more types of biotinylated lipids and one or more types of electrically-conductive lipids over a water-miscible liquid subphase. Conjugated molecules comprising a biotin-binding component made up of an avidin or streptavidin molecule or a fragment or derivative thereof having biotin-binding activity and a photodynamic proteinaceous component are then injected into the subphase. Because of the affinity between biotin and the biotin-binding component, the conjugated molecules bind to the biotinylated lipids. The air-subphase interface is then compressed, causing the biotinylated lipids and electrically-conductive lipids to form a monolayer thereat. In one embodiment, the biotin-binding component has biotin-binding sites available on its underside which may be used to bind biotinylated derivatives of one or more different species of photodynamic proteinaceous components and/or to build up a multilayered complex of biotin-binding molecules and functional proteinaceous components using biotinylated rigid or flexible couplers.
摘要:
A photodetection device uses configurations of photodynamic proteins which exhibit a change in electrical conductivity in response to a corresponding change in incident light intensity in the presence of an applied voltage. The photodynamic proteins are coupled to an electrical conductor, a voltage source and a conductivity sensor. The photodynamic protein complex includes at least one layer of a photodynamic protein and preferably includes a multi-layered thin-film structure with each layer comprised of either a photodynamic protein or a conductive polymer or oligomer. Groups of linked photodetectors where the photodetectors have different, but overlapping, spectral response ranges are used to detect specific wavelengths of incident light. An array of these groups of linked photodetectors arranged in a predetermined spatial pattern allows detection of both colon and images. An image processing system is constructed from this array of groups of linked photodetectors by coupling the output of the array to a processing component and the output of the processing component to an output device. A dynamic adaptive camouflage system is derived from the image processing system by mounting the photodetectors and display devices on an apparatus to be camouflaged and displaying a spatially shifted image of the incident ambient light.
摘要:
A method of detecting the presence of a substance being monitored in a medium, selected from the group of substances including organophosphorus compounds and the metal ions Zn, Be and Bi, including the steps of: providing a 1,2-dioxetane phenyl phosphate compound; providing a phosphatase that catalytically degrades the 1,2-dioxetane phenyl phosphate compound to produce light, the catalytic activity of the phosphatase toward 1,2-dioxetane phenyl phosphate compound being altered by the substance being monitored; exposing the 1,2-dioxetane phenyl phosphate compound and the phosphatase together to a medium which may contain the substance being monitored; detecting light produced after the exposing step; and determining, from the detected light, the presence and concentration in the medium of the substance being monitored.
摘要:
A method for synthesizing enzyme-catalyzed polymers using the Langmuir-Blodgett technique. In one embodiment, the process comprises spreading one or more enzyme-polymerizable monomers on a water-miscible solvent. The monomers are sufficiently surface active that they align themselves on the air-solvent interface. Next, pressure is applied to the interface to form a monolayer made up of the monomers. An enzyme is then introduced into the solvent, causing polymerization of the monomers in the monolayer. The polymeric monolayers produced by the present method are easier to process and have reduced cross-linking and branching as compared to similar polymers produced in bulk by enzyme-catalyzed reactions.
摘要:
A metamaterial includes a dielectric substrate and an array of discrete resonators at the dielectric substrate, wherein each of the discrete resonators has a shape that is independently selected from: an F-type shape; an E-type shape; or a y-type shape. A parameter of a chiral metamaterial is determined and a chiral metamaterial having such a parameter is prepared by the use of a model of the chiral metamaterial. The metamaterial model includes an array of discrete resonators. In one embodiment, each of the discrete resonators has a shape that is independently selected from the group consisting of: an F-type shape; an E-type shape; and a y-type shape. To the metamaterial model, electromagnetic (EM) radiation, preferably plane-polarized EM radiation in a visible, ultraviolet or near-infrared region, having at least one wavelength that is larger than the largest dimension of at least resonator of the metamaterial model, is applied. Varying at least one characteristic of the metamaterial model and/or at least one wavelength of the applied EM radiation modulates EM interaction of the applied EM radiation with the metamaterial model, thereby determining a parameter of the chiral metamaterial. By the use of a model of the chiral metamaterial, a number of discrete resonators of a chiral metamaterial that are arrayed in a direction perpendicular to a propagation axis of EM radiation is also determined.
摘要:
Selective whole cell QCM biosensors are disclosed. Also disclosed are methods of making and using such whole cell QCM biosensors, e.g., to screen drugs and diagnose diseases.
摘要:
A metamaterial includes a dielectric substrate and an array of discrete resonators at the dielectric substrate, wherein each of the discrete resonators has a shape that is independently selected from: an F-type shape; an E-type shape; or a y-type shape. A parameter of a chiral metamaterial is determined and a chiral metamaterial having such a parameter is prepared by the use of a model of the chiral metamaterial. The metamaterial model includes an array of discrete resonators. In one embodiment, each of the discrete resonators has a shape that is independently selected from the group consisting of: an F-type shape; an E-type shape; and a y-type shape. To the metamaterial model, electromagnetic (EM) radiation, preferably plane-polarized EM radiation in a visible, ultraviolet or near-infrared region, having at least one wavelength that is larger than the largest dimension of at least resonator of the metamaterial model, is applied. Varying at least one characteristic of the metamaterial model and/or at least one wavelength of the applied EM radiation modulates EM interaction of the applied EM radiation with the metamaterial model, thereby determining a parameter of the chiral metamaterial. By the use of a model of the chiral metamaterial, a number of discrete resonators of a chiral metamaterial that are arrayed in a direction perpendicular to a propagation axis of EM radiation is also determined.
摘要:
In one embodiment according to the invention, there is provided a method of sensing a response of a living cell or virus to a change in conditions. The method comprises applying an essentially constant external electromotive force that causes oscillation of an acoustic wave device at essentially constant amplitude and frequency under steady state conditions. The acoustic wave device has attached at least one living cell or virus. A combined oscillating system including the acoustic wave device and the living cell or virus exhibits a fundamental frequency and at least one harmonic frequency of the combined oscillating system. The living cell or virus is exposed to a change in an environmental condition while oscillating the combined oscillating system under the essentially constant external electromotive force, whereby a response of the living cell or virus to the change in environmental condition will be indicated by a change in at least one of frequency and amplitude of the oscillation of at least one harmonic frequency of the combined oscillating system.