Abstract: A polymer synthesis apparatus (20) for building a polymer chain including a head assembly (21) having an array of nozzles (22) with each nozzle coupled to a reservoir (23) of liquid reagent (24), and a base assembly (25) having an array of reaction wells (26). A transport mechanism (27) aligns the reaction wells (26) and selected nozzles (22) for deposition of the liquid reagent (24) into selected reaction wells (26). A sliding seal (30) is positioned between the head assembly (21) and the base assembly (25) to form a common chamber (31) enclosing both the reaction well (26) and the nozzles (22) therein. A gas inlet (70) into the common chamber (31), upstream from the nozzles (22), and a gas outlet (71) out of the common chamber (31), downstream from the nozzles (22), sweeps the common chamber (31) of toxic fumes emitted by the reagents.

Abstract: The invention provides apparatus and methods for making arrays of functionalized binding sites on a support surface. The invention further provides apparatus and methods for sequencing oligonucleotides and for identifying the amino acid sequence of peptides that bind to biologically active macromolecules, by specifically binding biologically active macromolecules to arrays of peptides or peptide mimetics.

Abstract: A polymer synthesis apparatus (20) for building a polymer chain including a head assembly (21) having an array of nozzles (22) with each nozzle coupled to a reservoir (23) of liquid reagent (24) , and a base assembly (25) having an array of reaction wells (26). A transport mechanism (27) aligns the reaction wells (26) and selected nozzles (22) for deposition of the liquid reagent (24) into selected reaction wells (26). A sliding seal (30) is positioned between the head assembly (21) and the base assembly (25) to form a common chamber (31) enclosing both the reaction well (26) and the nozzles (22) therein. A gas inlet (70) into the common chamber (31), upstream from the nozzles (22), and a gas outlet (71) out of the common chamber (31) , downstream from the nozzles (22) , sweeps the common chamber ( 31 ) of toxic fumes emitted by the reagents.

Abstract: Methods and compositions for forming ligation product hybridized to a nucleic acid template. The ligation product is formed by contacting a nucleic acid template with a primer capable of hybridizing to the template to form a primed template. The primed template is then contacted with a pool of random extension oligonucleotides of length N and an enzyme system. The enzyme system is capable of covalently linking the primer to an extension oligonucleotide adjacently hybridized to it and one or more other extension oligonucleotides adjacently hybridized to the ligation product defined by covalently linked ligation primer and one or more extension oligonucleotides. When covalently linked, the ligation product is hybridized to the nucleic acid template. Modifications permit the determination of the nucleotide sequence of one or more members of a first set of target nucleotide residues in the nucleic acid template that are spaced at intervals of N nucleotides.

Abstract: A photodetector that is responsive to a wavelength or wavelengths of interest which have heretofore been unrealized. The photodetector includes a resonant cavity structure bounded by first and second reflectors, the resonant cavity structure being resonant at the wavelength or wavelengths of interest for containing a plurality of standing waves therein. The photodetector further includes a radiation absorbing region disposed within the resonant cavity structure, the radiation absorbing region including a plurality of radiation absorbing layers spaced apart from one another by a distance substantially equal to a distance between antinodes of adjacent ones of the standing waves. Each of radiation absorbing layers is spatially positioned at a location of one of the antinodes of one of the standing waves such that radiation absorption is enhanced. The radiation absorbing layers may be either bulk layers or quantum wells includes a plurality of layers, each of which is comprised of a strained layer of InGaAs.

Abstract: An asymmetric Fabry-Perot reflectance modulator (AFPM) consists of an active region between top and bottom mirrors, the bottom mirror being affixed to a substrate by a buffer layer. The active region comprises a strained-layer region having a bandgap and thickness chosen for resonance at the Fabry-Perot frequency. The mirrors are lattice matched to the active region, and the buffer layer is lattice matched to the mirror at the interface. The device operates at wavelengths of commercially available semiconductor lasers.

Abstract: This invention relates to the apparatus, for sequencing natural or recombinant DNA and other polynucleotides. In particular, this invention relates to a method for sequencing polynucleotides based on mass spectrometry to determine which of the four bases (adenine, guanine, cytosine or thymine) is a component of the terminal nucleotide. In particular, the present invention relates to identifying the individual nucleotides by the mass of stable nuclide markers contained within either the dideoxynucleotides, the DNA primer, or the deoxynucleotide added to the primer. This invention is particularly useful in identifying specific DNA sequences in very small quantities in biological products produced by fermentation or other genetic engineering techniques. The invention is therefore useful in evaluating safety and other health concerns related to the presence of DNA in products resulting from genetic engineering techniques.

Abstract: A method for on-line accurate monitoring and precise control of molecular beam epitaxial growth of Groups III-III-V or Groups III-V-V layers in an advanced semiconductor device incorporates reflection mass spectrometry. The reflection mass spectrometry is responsive to intentional perturbations in molecular fluxes incident on a substrate by accurately measuring the molecular fluxes reflected from the substrate.The reflected flux is extremely sensitive to the state of the growing surface and the measurements obtained enable control of newly forming surfaces that are dynamically changing as a result of growth.

Abstract: Planar-buried-heterostructure, graded-index, separate-confinement-heterostructure semiconductor diode laser 10 includes a single quantum well or multi-quantum well active stripe 12 disposed between a p-type compositionally graded Group III-V cladding lever 14 and an n-type compositionally graded Group III-V cladding layer 16. The laser 10 includes an iion implanted n-type region 28 within the p-type cladding layer 14 and further includes an ion implanted p-type region 26 within the n-type cladding layer 16. The ion implanted regions are disposed for defining a lateral extent of the active stripe.

Abstract: The invention herein provides a picoliter fluid pumping device in combination with an electrophoresis unit. The picoliter fluid pumping device includes an actuating unit, for selectively generating pump actuating signals, and a pump unit. The pump unit includes a deforming means, a deformable fluid chamber having a deformable chamber segment, a nozzle port, and an inlet port coupled to a fluid source to provide a fluid to the deformable fluid chamber. The deforming means, coupled to the actuating unit, deforms the deformable chamber segment in response to a pump actuating signal to cause a picoliter quantity of the fluid to be emitted from the nozzle port. The picoliter fluid pumping device has in combination an electrophoresis unit having at least one electrophoresis electrode coupled to the deformable fluid chamber and spatially located near the nozzle port and at least one electrophoresis port coupled to the deformable fluid chamber and spatially located near the nozzle port.

Abstract: A Planar-Buried-Heterostructure, Graded-Index, Separate-Confinement-Heterostructure semiconductor diode laser 10 includes a single quantum well or multi-quantum well active stripe 12 disposed between a p-type compositionally graded Group III-V cladding layer 14 and an n-type compositionally graded Group III-V cladding layer 16. The laser 10 includes an ion implanted n-type region 28 within the p-type cladding layer 14 and further includes an ion implanted p-type region 26 within the n-type cladding layer 16. The ion implanted regions are disposed for defining a lateral extent of the active stripe.

Abstract: This invention relates to the methods, apparatus, reagents and mixtures of reagents for sequencing natural or recombinant DNA and other polynucleotides. In particular, this invention relates to a method for sequencing polynucleotides based on mass spectrometry to determine which of the four bases (adenine, guanine, cytosine or thymine) is a component of the terminal nucleotide. In particular, the present invention relates to identifying the individual nucleotides by the mass of stable nuclide markers contained within either the dideoxynucleotides, the DNA primer, or the deoxynucleotide added to the primer. This invention is particularly useful in identifying specific DNA sequences in very small quantities in biological products produced by fermentation or other genetic engineering techniques. The invention is therefore useful in evaluating safety and other health concerns related to the presence of DNA in products resulting from genetic engineering techniques.

Abstract: Amides of L-aspartyl-D-amino acid dipeptides of the formula ##STR1## and physiologically acceptable cationic and acid addition salts thereof wherein R.sup.a is methyl, ethyl, n-propyl or isopropyl; R is a branched member selected from the group consisting of fenchyl, diisopropylcarbinyl, d-methyl-t-butylcarbinyl, d-ethyl-t-butylcarbinyl, di-t-butylcarbinyl, 2-methylthio-2,4-dimethylpentan-3-yl, ##STR2## where at least one of R.sup.3, R.sup.4, R.sup.5, R.sup.6 is alkyl having from one to four carbon atoms and the remainder are hydrogen or alkyl having from one to four carbon atoms, X is O, S, SO, SO.sub.2 C.dbd.O or CHOH; m is zero or 1-4, n and p are each zero, 1, 2 or 3 where the sum of n+p is not greater than 3 and the sum of the carbon atoms in R.sup.3, R.sup.4, R.sup.5 and R.sup.6 is not greater than six, and when both of R.sup.3 and R.sup.4 or R.sup.5 and R.sup.6 are alkyl they are methyl or ethyl, ##STR3## where one of R.sup.7, R.sup.8, R.sup.

Abstract: A wavelength resonant semiconductor gain medium is disclosed. The essential feature of this medium is a multiplicity of quantum-well gain regions separated by semiconductor spacer regions of higher bandgap. Each period of this medium consisting of one quantum-well region and the adjacent spacer region is chosen such that the total width is equal to an integral multiple of 1/2 the wavelength in the medium of the radiation with which the medium is interacting. Optical, electron-beam and electrical injection pumping of the medium is disclosed. This medium may be used as a laser medium for single devices or arrays either with or without reflectors, which may be either semiconductor or external.

Abstract: Amides of L-aspartyl-D-amino acid dipeptides of the formula ##STR1## and physiologically acceptable cationic and acid addition salts thereof wherein R.sup.a is methyl, hydroxymethyl, ethyl, n-propyl or isopropyl; R is ##STR2## where at least one of R.sup.3, R.sup.4, R.sup.5, R.sup.6 is alkyl having from one to four carbon atoms and the remainder are hydrogen or alkyl having from one to four carbon atoms, and the sum of the carbon atoms in R.sup.3, R.sup.4, R.sup.5 and R.sup.6 is not greater than six; and when both of R.sup.3 and R.sup.4 or R.sup.5 and R.sup.6 are alkyl, they are methyl or ethyl.Said amides are potent sweeteners having advantages over the prior art, edible compositions containing them, methods for their use in edible compositions and novel amine and amide intermediates useful in their production.

Abstract: Amides of L-aspartyl-D-amino acid dipeptides of the formula ##STR1## and physiologically acceptable cationic and acid addition salts thereof wherein R.sup.a is methyl, ethyl, n-propyl or isopropyl; R is a branched member selected from the group consisting of fenchyl, diisopropylcarbinyl, d-methyl-t-butylcarbinyl, d-ethyl-t-butylcarbinyl, di-t-butylcarbinyl, 2-methylthio-2,4-dimethylpentan-3-yl, ##STR2## where at least one of R.sup.3, R.sup.4, R.sup.5, R.sup.6 is alkyl having from one to four carbon atoms and the remainder are hydrogen or alkyl having from one to four carbon atoms, X is O, S, SO, SO.sub.2, C.dbd.O or CHOH; m is zero or 1-4, n and p are each zero, 1, 2 or 3 where the sum of n+p is not greater than 3 and the sum of the carbon atoms in R.sup.3, R.sup.4, R.sup.5 and R.sup.6 is not greater than six, and when both of R.sup.3 and R.sup.4 or R.sup.5 and R.sup.6 are alkyl they are methyl or ethyl, ##STR3## where one of R.sup.7, R.sup.8, R.sup.

Abstract: Amides of L-aspartyl-D-amino acid dipeptides of the formula ##STR1## and physiologically acceptable cationic and acid addition salts thereof wherein R.sup.a is methyl, ethyl, n-propyl or isopropyl; R is a branched member selected from the group consisting of fenchyl, diisopropylcarbinyl, d-methyl-t-butylcarbinyl, d-ethyl-t-butylcarbinyl, di-t-butylcarbinyl, 2-methylthio-2,4-dimethylpentan-3-yl, ##STR2## where at least one of R.sup.3, R.sup.4, R.sup.5, R.sup.6 is alkyl having from one to four carbon atoms and the remainder are hydrogen or alkyl having from one to four carbon atoms, X is O, S, SO, SO.sub.2, C.dbd.O or CHOH; m is zero or 1-4, n and p are each zero, 1, 2 or 3 where the sum of n+p is not greater than 3 and the sum of the carbon atoms in R.sup.3, R.sup.4, R.sup.5 and R.sup.6 is not greater than six, and when both of R.sup.3 and R.sup.4 or R.sup.5 and R.sup.6 are alkyl they are methyl or ethyl, ##STR3## where one of R.sup.7, R.sup.8, R.sup.

Abstract: Amides of L-aspartyl-D-amino acid dipeptides of the formula ##STR1## and physiologically acceptable cationic and acid addition salts thereof wherein R.sup.a is methyl, hydroxymethyl, ethyl, n-propyl or isopropyl; R is ##STR2## where at least one of R.sup.3, R.sup.4, R.sup.5, R.sup.6 is alkyl having from one to four carbon atoms and the remainder are hydrogen or alkyl having from one to four carbon atoms, and the sum of the carbon atoms in R.sup.3, R.sup.4, R.sup.5 and R.sup.6 is not greater than six; and when both of R.sup.3 and R.sup.4 or R.sup.5 and R.sup.6 are alkyl, they are methyl or ethyl.Said amides are potent sweeteners having advantages over the prior art, edible compositions containing them, methods for their use in edible compositions and novel amine and amide intermediates useful in their production.

Abstract: A miniature, nonevacuated, detector refrigerator assembly for use in infrared imaging systems is described. The assembly incorporates a miniature Joule-Thomson laminar refrigerator which serves as the substrate for the detector subassembly, electrical leads, as well as the primary structural element of the assembly. The detector subassembly is positioned on the cold region of the refrigerator, surrounded by two prefabricated vacuum chambers and capped by an optical window or filter as required. As a result, the detector is easily built and is cooled in an efficient manner.

Abstract: A passive night vision reflex sight with a wide F.O.V. and designed for attachment to a weapon, such as a rifle, is disclosed. The night vision reflex sight preferably is designed for use in combination with a night vision goggle; it can also be used as in daylight without such a goggle, however. When in place, it continues to allow the use of the daytime battle sight of the weapon. The night vision reflex sight comprises a sight for viewing an image of a scene along a line of sight, a photoreceptive sensor aligned with the line of sight and viewing the image, a battery powered red L.E.D., together with a reticle, a lens, and a filter for generating a pulsed or d.c. light and for directing it at the reflex sight, with the sight reflecting the pulsed or d.c. light into the photoreceptive sensor and superimposing it on the image. Preferably, the reticle is adjustable, the pulsed light is pulsed at a rate between about two to about twelve c.p.s.