Abstract: Double-heterostructure (DH) diode lasers based upon very thin epitaxial layers of Ga.sub.x In.sub.1-x As.sub.y P.sub.1-y grown on and lattice-matched to oriented InP substrates are disclosed. A preferred method for fabricating such lasers involves the successive growth, on an InP substrate, of an InP buffer layer, the GaInAsP active layer and an InP top barrier layer using liquid phase epitaxy techniques to grow these layers from supercooled solutions. Stripe geometry lasers can be fabricated from these materials which emit in the 1.1-1.3 .mu.m range and are capable of cw operation for extended periods at room temperature.

Abstract: A method for enhancing the production of interferon from normal human diploid fibroblast cells is disclosed. In this method, a distinct interferon-production phase is established in which the temperature is initially elevated for a brief period followed by a reduction in temperature for the balance of the interferon-production phase.

Abstract: A quantitative bioassay employing the well known diffusion bioassay is described herein. The bioassay allows the calculation of the minimum concentration of a test agent which produces mutation in a tester strain of cells employed in the diffusion bioassay. A novel method for determining the stability of the agent tested in the test environment is also described.

Abstract: This invention relates to crosslinked collagen and glycosaminoglycan materials, and to procedures for preparing such materials. It has been discovered that if collagen fibrils in an aqueous acidic solution are contacted with a crosslinking agent before being contacted with glycosaminoglycan, the materials produced have extremely low levels of thrombogenicity. Such materials are well suited for in-dwelling catheters, blood vessel grafts, and other devices that are in continuous contact with blood for long periods of time.

Abstract: Transparent heat-mirrors are disclosed which are comprised of composite films. These films include a discrete and continuous layer of metallic silver sandwiched between a transparent, outer, protective, anti-reflection layer and a transparent, phase-matching layer. This combination of layers is chosen to provide high solar transmission with minimum loss of thermal radiation. Transparent heat-mirrors are useful in the collection and trapping of solar energy, and in other applications where it is desired or necessary to have high infrared reflectivity with high solar transmission.

Abstract: An improved method for assaying for cancer by detecting .beta.-linked galactose moieties associated with cells is disclosed wherein a label specific for such moieties is added to the cells and subsequently sensed.

Abstract: An improved method for crystallizing amorphous material with a moving beam of energy is disclosed. In this method, the energy beam is scanned in a manner to provide controlled, continuous motion of the crystallization front.

Abstract: A method of producing transplantable sheets of living keratinous tissue by culturing keratinocytes in a culture vessel and subsequently enzymatically detaching a sheet of keratinous tissue employing an enzyme, such as Dispase, is disclosed herein.

Abstract: An assay is disclosed for determining mutagenic damage caused by the administration of a known or suspected mutagen to diploid human lymphoblastoid cell lines. The gene locus employed for this assay is the gene for thymidine kinase, uridine kinase, or cytidine deaminase. Since human lymphoblastoid cells contain two genes for these enzymes, heterozygotes of human lymphoblastoid cells are used in this assay.

Abstract: An assay is disclosed for determining mutagenic damage caused by the administration of a known or suspected mutagen to bacterial cells such as Salmonella typhimurium. After administration of or exposure to a mutagenic agent, the bacterial cells are plated in the presence of a purine analog and resistance to purine analogs is used as the genetic marker. This bioassay system can be used by genetic toxicologists to determine the potential genetic hazards from the use of a variety of suspected or known mutagens, including newly-developed chemicals.

Abstract: Improved cell culture microcarriers, and methods for their production and use, are disclosed herein. These improved microcarriers have positive charge capacities adjusted and/or controlled within a range suitable for good cell growth. One method for producing such improved microcarriers is by treating beads formed from polymers containing pendant hydroxy groups, such as dextran beads, with an aqueous solution of an alkaline material and a chloro- or bromo-substituted tertiary amine under precisely controlled conditions to produce the desired exchange capacity. The resultant positively charged microcarriers have been used in microcarrier cultures to produce outstanding growth of anchorage-dependent cells. Such cells can be harvested, or used for the production of viruses, vaccines, hormones, interferon or other cellular growth by-products.

Abstract: Double-heterostructure (DH) diode lasers based upon very thin epitaxial layers of Ga.sub.x In.sub.1-x As.sub.y P.sub.1-y grown on and lattice-matched to oriented InP substrates are disclosed. A preferred method for fabricating such lasers involves the successive growth, on an InP substrate, of an InP buffer layer, the GaInAsP active layer and an InP top barrier layer using liquid phase epitaxy techniques to grow these layers from supercooled solutions. Stripe geometry lasers can be fabricated from these materials which emit in the 1.1-1.3 .mu.m range and are capable of cw operation for extended periods at room temperature.

Abstract: An improved synthesis is disclosed for 7-alkylamino-3-methylpyrazolo[4,3-d]pyrimidines, which are known to be potent cytokinin antagonists.

Abstract: Composite materials are disclosed which are formed by contacting collagen with a mucopolysaccharide and subsequently covalently crosslinking the resultant polymer. These composite materials have a balance of mechanical, chemical and physiological properties which make them useful in surgical sutures and prostheses of controlled biodegradability (resorption) and controlled ability to prevent development of a foreign body reaction, and many are also useful in applications in which blood compatibility is required.

Abstract: An apparatus and process useful in direct fluorination of a variety of compositions, as well as the fluorinated compositions themselves, are disclosed.The apparatus comprises a cryogenic zone reactor, such as a packed column reactor, suitably divided into a plurality of independently controllable cryogenic temperature zones. Means are also provided to introduce a reactant to be fluorinated as well as to introduce a mixture of fluorine gas and an inert gas.New fluorinated compounds are also disclosed. These include: perfluoro-2-methoxyethyl ether; perfluoro-1,4-dioxane; perfluoro-2,5-diketohexane; perfluorohexamethylethane; and monohydropentadecafluoroadamantane.Additionally, new syntheses for trifluoroacetic acid, a commercially significant bulk chemical, are disclosed. One synthesis comprises producing perfluoroethyl acetate by direct fluorination using a cryogenic zone reactor, followed by hydrolysis of perfluoroethyl acetate. Two moles of the acid are produced for each mole of ester.

Abstract: An improved avalanche photodiode having an active layer of Ga.sub.x In.sub.1-x As.sub.y P.sub.1-y containing a p-n junction and a window layer grown epitaxially to an n.sup.+ substrate is disclosed herein, as well as methods for its fabrication.

Abstract: A cross flow filtration molding apparatus and method are disclosed which are particularly useful for forming complicated shapes from dispersions of particles in a liquid medium. Dispersion is pumped through a mold which has porous walls and a sufficient pressure differential is applied to drive a portion of the liquid medium through the porous walls which results in deposition of particles on the walls to form a shaped article. The shaped article may inherently have sufficient structural integrity, or it may be post-treated to provide additional structural integrity.

Abstract: Transparent heat-mirrors are disclosed which are formed from tin-doped indium oxide films or antimony-doped tin oxide films deposited onto polymeric substrates. Low temperature deposition processes, such as ion-beam sputtering, are employed to preserve the polymeric substrates, and films having high transparency to visible radiation and high reflectivity to infrared radiation are deposited on the polymeric substrates by carefully controlling the partial pressure of oxygen during deposition.

Abstract: A method of applying an electrical contact and an anodic reflection coating to an n.sup.+ layer of a direct gap semiconductor device, comprising applying an anodizable metal contact to the n.sup.+ layer and thereafter anodizing the n.sup.+ layer whereby its thickness is reduced and an antireflection layer is formed thereover.

Abstract: Aqueous heat-storage compositions useful in space heating applications are disclosed which contain a phase-change material which absorbs and stores heat as it is heated above its phase-change temperature and releases stored heat as it is cooled below its phase-change temperature. These compositions include fumed silicon dioxide which acts as a stabilizing agent and provides dramatically prolonged heat-storage efficiency for these compositions as they undergo repetitive cycling through their phase-change temperature. Articles containing such compositions and methods of forming such compositions are additionally disclosed.