Benzoxazines: OXAZINES with a fused BENZENE ring.Oxazines: Six-membered heterocycles containing an oxygen and a nitrogen.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).Phloroglucinol: A trinitrobenzene derivative with antispasmodic properties that is used primarily as a laboratory reagent.Benzene: Toxic, volatile, flammable liquid hydrocarbon byproduct of coal distillation. It is used as an industrial solvent in paints, varnishes, lacquer thinners, gasoline, etc. Benzene causes central nervous system damage acutely and bone marrow damage chronically and is carcinogenic. It was formerly used as parasiticide.Methacrylates: Acrylic acids or acrylates which are substituted in the C-2 position with a methyl group.Polymerization: Chemical reaction in which monomeric components are combined to form POLYMERS (e.g., POLYMETHYLMETHACRYLATE).Maleic Hydrazide: 1,2-Dihydro-3,6-pyridazinedione. A herbicide and plant growth regulator; also used to control suckering of tobacco. Its residue in food and tobacco is highly toxic, causing CNS disturbances and liver damage.Acetic Acid: Product of the oxidation of ethanol and of the destructive distillation of wood. It is used locally, occasionally internally, as a counterirritant and also as a reagent. (Stedman, 26th ed)HydrazinesDatabases, Factual: Extensive collections, reputedly complete, of facts and data garnered from material of a specialized subject area and made available for analysis and application. The collection can be automated by various contemporary methods for retrieval. The concept should be differentiated from DATABASES, BIBLIOGRAPHIC which is restricted to collections of bibliographic references.Fonofos: An organothiophosphorus cholinesterase inhibitor that is used as an insecticide.Software: Sequential operating programs and data which instruct the functioning of a digital computer.H-2 Antigens: The major group of transplantation antigens in the mouse.Science: The study of natural phenomena by observation, measurement, and experimentation.Deoxyguanosine: A nucleoside consisting of the base guanine and the sugar deoxyribose.H-1 parvovirus: A species in the genus PARVOVIRUS that has the ability to replicate and kill tumor cells in culture.Health Services Accessibility: The degree to which individuals are inhibited or facilitated in their ability to gain entry to and to receive care and services from the health care system. Factors influencing this ability include geographic, architectural, transportational, and financial considerations, among others.Great BritainEthylene Glycols: An ethylene compound with two hydroxy groups (-OH) located on adjacent carbons. They are viscous and colorless liquids. Some are used as anesthetics or hypnotics. However, the class is best known for their use as a coolant or antifreeze.Carbonates: Salts or ions of the theoretical carbonic acid, containing the radical CO2(3-). Carbonates are readily decomposed by acids. The carbonates of the alkali metals are water-soluble; all others are insoluble. (From Grant & Hackh's Chemical Dictionary, 5th ed)Calcium Carbonate: Carbonic acid calcium salt (CaCO3). An odorless, tasteless powder or crystal that occurs in nature. It is used therapeutically as a phosphate buffer in hemodialysis patients and as a calcium supplement.Allyl CompoundsDrug Contamination: The presence of organisms, or any foreign material that makes a drug preparation impure.United States Dept. of Health and Human Services: A cabinet department in the Executive Branch of the United States Government concerned with administering those agencies and offices having programs pertaining to health and human services.Zidovudine: A dideoxynucleoside compound in which the 3'-hydroxy group on the sugar moiety has been replaced by an azido group. This modification prevents the formation of phosphodiester linkages which are needed for the completion of nucleic acid chains. The compound is a potent inhibitor of HIV replication, acting as a chain-terminator of viral DNA during reverse transcription. It improves immunologic function, partially reverses the HIV-induced neurological dysfunction, and improves certain other clinical abnormalities associated with AIDS. Its principal toxic effect is dose-dependent suppression of bone marrow, resulting in anemia and leukopenia.National Institutes of Health (U.S.): An operating division of the US Department of Health and Human Services. It is concerned with the overall planning, promoting, and administering of programs pertaining to health and medical research. Until 1995, it was an agency of the United States PUBLIC HEALTH SERVICE.Anti-HIV Agents: Agents used to treat AIDS and/or stop the spread of the HIV infection. These do not include drugs used to treat symptoms or opportunistic infections associated with AIDS.Acquired Immunodeficiency Syndrome: An acquired defect of cellular immunity associated with infection by the human immunodeficiency virus (HIV), a CD4-positive T-lymphocyte count under 200 cells/microliter or less than 14% of total lymphocytes, and increased susceptibility to opportunistic infections and malignant neoplasms. Clinical manifestations also include emaciation (wasting) and dementia. These elements reflect criteria for AIDS as defined by the CDC in 1993.HIV Infections: Includes the spectrum of human immunodeficiency virus infections that range from asymptomatic seropositivity, thru AIDS-related complex (ARC), to acquired immunodeficiency syndrome (AIDS).Clinical Trials as Topic: Works about pre-planned studies of the safety, efficacy, or optimum dosage schedule (if appropriate) of one or more diagnostic, therapeutic, or prophylactic drugs, devices, or techniques selected according to predetermined criteria of eligibility and observed for predefined evidence of favorable and unfavorable effects. This concept includes clinical trials conducted both in the U.S. and in other countries.PyransSpiro Compounds: A group of compounds consisting in part of two rings sharing one atom (usually a carbon) in common.Structure-Activity Relationship: The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.Heterocyclic Compounds: Ring compounds having atoms other than carbon in their nuclei. (Grant & Hackh's Chemical Dictionary, 5th ed)Nitro Compounds: Compounds having the nitro group, -NO2, attached to carbon. When attached to nitrogen they are nitramines and attached to oxygen they are NITRATES.Eye Protective Devices: Personal devices for protection of the eyes from impact, flying objects, glare, liquids, or injurious radiation.PhotochemistryPatents as Topic: Exclusive legal rights or privileges applied to inventions, plants, etc.Microwaves: That portion of the electromagnetic spectrum from the UHF (ultrahigh frequency) radio waves and extending into the INFRARED RAYS frequencies.InkSolvents: Liquids that dissolve other substances (solutes), generally solids, without any change in chemical composition, as, water containing sugar. (Grant & Hackh's Chemical Dictionary, 5th ed)Inventions: A novel composition, device, or process, independently conceived de novo or derived from a pre-existing model.Intellectual Property: Property, such as patents, trademarks, and copyright, that results from creative effort. The Patent and Copyright Clause (Art. 1, Sec. 8, cl. 8) of the United States Constitution provides for promoting the progress of science and useful arts by securing for limited times to authors and inventors, the exclusive right to their respective writings and discoveries. (From Black's Law Dictionary, 5th ed, p1014)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.Organometallic Compounds: A class of compounds of the type R-M, where a C atom is joined directly to any other element except H, C, N, O, F, Cl, Br, I, or At. (Grant & Hackh's Chemical Dictionary, 5th ed)Particle Accelerators: Devices which accelerate electrically charged atomic or subatomic particles, such as electrons, protons or ions, to high velocities so they have high kinetic energy.Razoxane: An antimitotic agent with immunosuppressive properties.Salts: Substances produced from the reaction between acids and bases; compounds consisting of a metal (positive) and nonmetal (negative) radical. (Grant & Hackh's Chemical Dictionary, 5th ed)HIV-1: The type species of LENTIVIRUS and the etiologic agent of AIDS. It is characterized by its cytopathic effect and affinity for the T4-lymphocyte.HIV Reverse Transcriptase: A reverse transcriptase encoded by the POL GENE of HIV. It is a heterodimer of 66 kDa and 51 kDa subunits that are derived from a common precursor protein. The heterodimer also includes an RNAse H activity (RIBONUCLEASE H, HUMAN IMMUNODEFICIENCY VIRUS) that plays an essential role the viral replication process.Virus Replication: The process of intracellular viral multiplication, consisting of the synthesis of PROTEINS; NUCLEIC ACIDS; and sometimes LIPIDS, and their assembly into a new infectious particle.Reverse Transcriptase Inhibitors: Inhibitors of reverse transcriptase (RNA-DIRECTED DNA POLYMERASE), an enzyme that synthesizes DNA on an RNA template.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.