Fluorocarbon PolymersFluorocarbons: Liquid perfluorinated carbon compounds which may or may not contain a hetero atom such as nitrogen, oxygen or sulfur, but do not contain another halogen or hydrogen atom. This concept includes fluorocarbon emulsions and fluorocarbon blood substitutes.Chlorofluorocarbons, Methane: A group of methane-based halogenated hydrocarbons containing one or more fluorine and chlorine atoms.Polymers: Compounds formed by the joining of smaller, usually repeating, units linked by covalent bonds. These compounds often form large macromolecules (e.g., BIOPOLYMERS; PLASTICS).Aerosol Propellants: Compressed gases or vapors in a container which, upon release of pressure and expansion through a valve, carry another substance from the container. They are used for cosmetics, household cleaners, and so on. Examples are BUTANES; CARBON DIOXIDE; FLUOROCARBONS; NITROGEN; and PROPANE. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Dyspnea, Paroxysmal: A disorder characterized by sudden attacks of respiratory distress in at rest patients with HEART FAILURE and PULMONARY EDEMA. It usually occurs at night after several hours of sleep in a reclining position. Patients awaken with a feeling of suffocation, coughing, a cold sweat, and TACHYCARDIA. When there is significant WHEEZING, it is called cardiac asthma.Blood Substitutes: Substances that are used in place of blood, for example, as an alternative to BLOOD TRANSFUSIONS after blood loss to restore BLOOD VOLUME and oxygen-carrying capacity to the blood circulation, or to perfuse isolated organs.Bromochlorofluorocarbons: A series of hydrocarbons containing BROMINE; CHLORINE and FLOURINE.Refrigeration: The mechanical process of cooling.Surface-Active Agents: Agents that modify interfacial tension of water; usually substances that have one lipophilic and one hydrophilic group in the molecule; includes soaps, detergents, emulsifiers, dispersing and wetting agents, and several groups of antiseptics.Emulsions: Colloids formed by the combination of two immiscible liquids such as oil and water. Lipid-in-water emulsions are usually liquid, like milk or lotion. Water-in-lipid emulsions tend to be creams. The formation of emulsions may be aided by amphiphatic molecules that surround one component of the system to form MICELLES.Hydrophobic and Hydrophilic Interactions: The thermodynamic interaction between a substance and WATER.Surface Properties: Characteristics or attributes of the outer boundaries of objects, including molecules.Oxygen: An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.Fluorine: A nonmetallic, diatomic gas that is a trace element and member of the halogen family. It is used in dentistry as flouride (FLUORIDES) to prevent dental caries.Halogenation: Covalent attachment of HALOGENS to other compounds.Dichloroethylenes: Toxic chlorinated unsaturated hydrocarbons. Include both the 1,1- and 1,2-dichloro isomers. Both isomers are toxic, but 1,1-dichloroethylene is the more potent CNS depressant and hepatotoxin. It is used in the manufacture of thermoplastic polymers.Chromium: A trace element that plays a role in glucose metabolism. It has the atomic symbol Cr, atomic number 24, and atomic weight 52. According to the Fourth Annual Report on Carcinogens (NTP85-002,1985), chromium and some of its compounds have been listed as known carcinogens.Gas PoisoningWeldingPubMed: A bibliographic database that includes MEDLINE as its primary subset. It is produced by the National Center for Biotechnology Information (NCBI), part of the NATIONAL LIBRARY OF MEDICINE. PubMed, which is searchable through NLM's Web site, also includes access to additional citations to selected life sciences journals not in MEDLINE, and links to other resources such as the full-text of articles at participating publishers' Web sites, NCBI's molecular biology databases, and PubMed Central.Periodicals as Topic: A publication issued at stated, more or less regular, intervals.Metered Dose Inhalers: A small aerosol canister used to release a calibrated amount of medication for inhalation.Nebulizers and Vaporizers: Devices that cause a liquid or solid to be converted into an aerosol (spray) or a vapor. It is used in drug administration by inhalation, humidification of ambient air, and in certain analytical instruments.Encyclopedias as Topic: Works containing information articles on subjects in every field of knowledge, usually arranged in alphabetical order, or a similar work limited to a special field or subject. (From The ALA Glossary of Library and Information Science, 1983)Electric Power Supplies: Devices that control the supply of electric current for running electrical equipment.Sulfonic Acids: Inorganic or organic oxy acids of sulfur which contain the RSO2(OH) radical.Micro-Electrical-Mechanical Systems: A class of devices combining electrical and mechanical components that have at least one of the dimensions in the micrometer range (between 1 micron and 1 millimeter). They include sensors, actuators, microducts, and micropumps.Electrodes: Electric conductors through which electric currents enter or leave a medium, whether it be an electrolytic solution, solid, molten mass, gas, or vacuum.Cantharidin: A toxic compound, isolated from the Spanish fly or blistering beetle (Lytta (Cantharis) vesicatoria) and other insects. It is a potent and specific inhibitor of protein phosphatases 1 (PP1) and 2A (PP2A). This compound can produce severe skin inflammation, and is extremely toxic if ingested orally.Ion Exchange Resins: High molecular weight, insoluble polymers which contain functional groups that are capable of undergoing exchange reactions (ION EXCHANGE) with either cations or anions.Cation Exchange Resins: High molecular weight insoluble polymers which contain functional anionic groups that are capable of undergoing exchange reactions with cations.Anion Exchange Resins: High-molecular-weight insoluble polymers that contain functional cationic groups capable of undergoing exchange reactions with anions.Electrolysis: Destruction by passage of a galvanic electric current, as in disintegration of a chemical compound in solution.Pinus ponderosa: A plant species of the genus PINUS that contains isocupressic acid.Bioelectric Energy Sources: Electric power supply devices which convert biological energy, such as chemical energy of metabolism or mechanical energy of periodic movements, into electrical energy.Resins, Synthetic: Polymers of high molecular weight which at some stage are capable of being molded and then harden to form useful components.Patents as Topic: Exclusive legal rights or privileges applied to inventions, plants, etc.Repetitive Sequences, Nucleic Acid: Sequences of DNA or RNA that occur in multiple copies. There are several types: INTERSPERSED REPETITIVE SEQUENCES are copies of transposable elements (DNA TRANSPOSABLE ELEMENTS or RETROELEMENTS) dispersed throughout the genome. TERMINAL REPEAT SEQUENCES flank both ends of another sequence, for example, the long terminal repeats (LTRs) on RETROVIRUSES. Variations may be direct repeats, those occurring in the same direction, or inverted repeats, those opposite to each other in direction. TANDEM REPEAT SEQUENCES are copies which lie adjacent to each other, direct or inverted (INVERTED REPEAT SEQUENCES).Foramen Ovale, Patent: A condition in which the FORAMEN OVALE in the ATRIAL SEPTUM fails to close shortly after birth. This results in abnormal communications between the two upper chambers of the heart. An isolated patent ovale foramen without other structural heart defects is usually of no hemodynamic significance.Search Engine: Software used to locate data or information stored in machine-readable form locally or at a distance such as an INTERNET site.Alkadienes: Acyclic branched or unbranched hydrocarbons having two carbon-carbon double bonds.Internet: A loose confederation of computer communication networks around the world. The networks that make up the Internet are connected through several backbone networks. The Internet grew out of the US Government ARPAnet project and was designed to facilitate information exchange.Molecular Structure: The location of the atoms, groups or ions relative to one another in a molecule, as well as the number, type and location of covalent bonds.Polytetrafluoroethylene: Homopolymer of tetrafluoroethylene. Nonflammable, tough, inert plastic tubing or sheeting; used to line vessels, insulate, protect or lubricate apparatus; also as filter, coating for surgical implants or as prosthetic material. Synonyms: Fluoroflex; Fluoroplast; Ftoroplast; Halon; Polyfene; PTFE; Tetron.Stents: Devices that provide support for tubular structures that are being anastomosed or for body cavities during skin grafting.Dental Porcelain: A type of porcelain used in dental restorations, either jacket crowns or inlays, artificial teeth, or metal-ceramic crowns. It is essentially a mixture of particles of feldspar and quartz, the feldspar melting first and providing a glass matrix for the quartz. Dental porcelain is produced by mixing ceramic powder (a mixture of quartz, kaolin, pigments, opacifiers, a suitable flux, and other substances) with distilled water. (From Jablonski's Dictionary of Dentistry, 1992)Blood Vessel Prosthesis: Device constructed of either synthetic or biological material that is used for the repair of injured or diseased blood vessels.Thermodynamics: A rigorously mathematical analysis of energy relationships (heat, work, temperature, and equilibrium). It describes systems whose states are determined by thermal parameters, such as temperature, in addition to mechanical and electromagnetic parameters. (From Hawley's Condensed Chemical Dictionary, 12th ed)Polyethylene Terephthalates: Polyester polymers formed from terephthalic acid or its esters and ethylene glycol. They can be formed into tapes, films or pulled into fibers that are pressed into meshes or woven into fabrics.Lewis Acids: Any chemical species which accepts an electron-pair from a LEWIS BASE in a chemical bonding reaction.Phosphoramides: Amide derivatives of phosphoric acid such as compounds that include the phosphoric triamide (P(=O)(N)(N)(N)) structure.Catalysis: The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.Epoxy Compounds: Organic compounds that include a cyclic ether with three ring atoms in their structure. They are commonly used as precursors for POLYMERS such as EPOXY RESINS.Halogens: A family of nonmetallic, generally electronegative, elements that form group 17 (formerly group VIIa) of the periodic table.Organotin Compounds: Organic compounds which contain tin in the molecule. Used widely in industry and agriculture.