Triazines: Heterocyclic rings containing three nitrogen atoms, commonly in 1,2,4 or 1,3,5 or 2,4,6 formats. Some are used as HERBICIDES.Explosive Agents: Substances that are energetically unstable and can produce a sudden expansion of the material, called an explosion, which is accompanied by heat, pressure and noise. Other things which have been described as explosive that are not included here are explosive action of laser heating, human performance, sudden epidemiological outbreaks, or fast cell growth.Herbicides: Pesticides used to destroy unwanted vegetation, especially various types of weeds, grasses (POACEAE), and woody plants. Some plants develop HERBICIDE RESISTANCE.Atrazine: A selective triazine herbicide. Inhalation hazard is low and there are no apparent skin manifestations or other toxicity in humans. Acutely poisoned sheep and cattle may show muscular spasms, fasciculations, stiff gait, increased respiratory rates, adrenal degeneration, and congestion of the lungs, liver, and kidneys. (From The Merck Index, 11th ed)Dendrimers: Tree-like, highly branched, polymeric compounds. They grow three-dimensionally by the addition of shells of branched molecules to a central core. The overall globular shape and presence of cavities gives potential as drug carriers and CONTRAST AGENTS.Simazine: A triazine herbicide.Trinitrotoluene: A 2,4,6-trinitrotoluene, which is an explosive chemical that can cause skin irritation and other toxic consequences.Biodegradation, Environmental: Elimination of ENVIRONMENTAL POLLUTANTS; PESTICIDES and other waste using living organisms, usually involving intervention of environmental or sanitation engineers.Gordonia Bacterium: A genus of gram-positive BACTERIA in the family Gordoniaceae, isolated from soil and from sputa of patients with chest disorders. It is also used for biotransformation of natural products.Rodenticides: Substances used to destroy or inhibit the action of rats, mice, or other rodents.Coloring Agents: Chemicals and substances that impart color including soluble dyes and insoluble pigments. They are used in INKS; PAINTS; and as INDICATORS AND REAGENTS.Rhodococcus: A bacterial genus of the order ACTINOMYCETALES.Ferrozine: A ferroin compound that forms a stable magenta-colored solution with the ferrous ion. The complex has an absorption peak at 562 nm and is used as a reagent and indicator for iron.Pyrazolones: Compounds with a five-membered heterocyclic ring with two nitrogens and a keto OXYGEN. Some are inhibitors of TNF-ALPHA production.Soil Pollutants: Substances which pollute the soil. Use for soil pollutants in general or for which there is no specific heading.Folic Acid Antagonists: Inhibitors of the enzyme, dihydrofolate reductase (TETRAHYDROFOLATE DEHYDROGENASE), which converts dihydrofolate (FH2) to tetrahydrofolate (FH4). They are frequently used in cancer chemotherapy. (From AMA, Drug Evaluations Annual, 1994, p2033)Cyclization: Changing an open-chain hydrocarbon to a closed ring. (McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)Fluorine Compounds: Inorganic compounds that contain fluorine as an integral part of the molecule.SemicarbazonesMolecular 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.Water Pollutants, Chemical: Chemical compounds which pollute the water of rivers, streams, lakes, the sea, reservoirs, or other bodies of water.Isonipecotic AcidsAdenosine A2 Receptor Antagonists: Compounds that selectively bind to and block the activation of ADENOSINE A2 RECEPTORS.Pesticides: Chemicals used to destroy pests of any sort. The concept includes fungicides (FUNGICIDES, INDUSTRIAL); INSECTICIDES; RODENTICIDES; etc.Indicators and Reagents: Substances used for the detection, identification, analysis, etc. of chemical, biological, or pathologic processes or conditions. Indicators are substances that change in physical appearance, e.g., color, at or approaching the endpoint of a chemical titration, e.g., on the passage between acidity and alkalinity. Reagents are substances used for the detection or determination of another substance by chemical or microscopical means, especially analysis. Types of reagents are precipitants, solvents, oxidizers, reducers, fluxes, and colorimetric reagents. (From Grant & Hackh's Chemical Dictionary, 5th ed, p301, p499)Drug Delivery Systems: Systems for the delivery of drugs to target sites of pharmacological actions. Technologies employed include those concerning drug preparation, route of administration, site targeting, metabolism, and toxicity.PolyaminesDrug Carriers: Forms to which substances are incorporated to improve the delivery and the effectiveness of drugs. Drug carriers are used in drug-delivery systems such as the controlled-release technology to prolong in vivo drug actions, decrease drug metabolism, and reduce drug toxicity. Carriers are also used in designs to increase the effectiveness of drug delivery to the target sites of pharmacological actions. Liposomes, albumin microspheres, soluble synthetic polymers, DNA complexes, protein-drug conjugates, and carrier erythrocytes among others have been employed as biodegradable drug carriers.Nanoparticles: Nanometer-sized particles that are nanoscale in three dimensions. They include nanocrystaline materials; NANOCAPSULES; METAL NANOPARTICLES; DENDRIMERS, and QUANTUM DOTS. The uses of nanoparticles include DRUG DELIVERY SYSTEMS and cancer targeting and imaging.Patient Access to Records: The freedom of patients to review their own medical, genetic, or other health-related records.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).Polymerization: Chemical reaction in which monomeric components are combined to form POLYMERS (e.g., POLYMETHYLMETHACRYLATE).Periodicals as Topic: A publication issued at stated, more or less regular, intervals.Journal Impact Factor: A quantitative measure of the frequency on average with which articles in a journal have been cited in a given period of time.Ultraviolet Rays: That portion of the electromagnetic spectrum immediately below the visible range and extending into the x-ray frequencies. The longer wavelengths (near-UV or biotic or vital rays) are necessary for the endogenous synthesis of vitamin D and are also called antirachitic rays; the shorter, ionizing wavelengths (far-UV or abiotic or extravital rays) are viricidal, bactericidal, mutagenic, and carcinogenic and are used as disinfectants.Zirconium: Zirconium. A rather rare metallic element, atomic number 40, atomic weight 91.22, symbol Zr. (From Dorland, 28th ed)Chemical Safety: Risk or hazard associated with the handling and use of chemicals.Geologic Sediments: A mass of organic or inorganic solid fragmented material, or the solid fragment itself, that comes from the weathering of rock and is carried by, suspended in, or dropped by air, water, or ice. It refers also to a mass that is accumulated by any other natural agent and that forms in layers on the earth's surface, such as sand, gravel, silt, mud, fill, or loess. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed, p1689)Hazardous Substances: Elements, compounds, mixtures, or solutions that are considered severely harmful to human health and the environment. They include substances that are toxic, corrosive, flammable, or explosive.Adsorption: The adhesion of gases, liquids, or dissolved solids onto a surface. It includes adsorptive phenomena of bacteria and viruses onto surfaces as well. ABSORPTION into the substance may follow but not necessarily.Toxicity Tests: An array of tests used to determine the toxicity of a substance to living systems. These include tests on clinical drugs, foods, and environmental pollutants.Formularies as Topic: Works about lists of drugs or collections of recipes, formulas, and prescriptions for the compounding of medicinal preparations. Formularies differ from PHARMACOPOEIAS in that they are less complete, lacking full descriptions of the drugs, their formulations, analytic composition, chemical properties, etc. In hospitals, formularies list all drugs commonly stocked in the hospital pharmacy.Sociometric Techniques: Methods for quantitatively assessing and measuring interpersonal and group relationships.Friends: Persons whom one knows, likes, and trusts.Peer Group: Group composed of associates of same species, approximately the same age, and usually of similar rank or social status.Hydroxyethyl Starch Derivatives: Starches that have been chemically modified so that a percentage of OH groups are substituted with 2-hydroxyethyl ether groups.Interpersonal Relations: The reciprocal interaction of two or more persons.Terminology as Topic: The terms, expressions, designations, or symbols used in a particular science, discipline, or specialized subject area.Safety: Freedom from exposure to danger and protection from the occurrence or risk of injury or loss. It suggests optimal precautions in the workplace, on the street, in the home, etc., and includes personal safety as well as the safety of property.Accidents, Occupational: Unforeseen occurrences, especially injuries in the course of work-related activities.Databases, Chemical: Databases devoted to knowledge about specific chemicals.Patents as Topic: Exclusive legal rights or privileges applied to inventions, plants, etc.Dictionaries, ChemicalSmall Molecule Libraries: Large collections of small molecules (molecular weight about 600 or less), of similar or diverse nature which are used for high-throughput screening analysis of the gene function, protein interaction, cellular processing, biochemical pathways, or other chemical interactions.