NaphthyridinesBiotin: A water-soluble, enzyme co-factor present in minute amounts in every living cell. It occurs mainly bound to proteins or polypeptides and is abundant in liver, kidney, pancreas, yeast, and milk.Hydrogen Bonding: A low-energy attractive force between hydrogen and another element. It plays a major role in determining the properties of water, proteins, and other compounds.Models, Molecular: Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.Pyrodictiaceae: A family of archaea, in the order DESULFUROCOCCALES consisting of anaerobic coccoid to disc-shaped cells. They grow either chemolithoautotrophically or by FERMENTATION. Three genera are recognized: Pyrodictium, Hyperthermus, and Pyrolobus.Crystallography, X-Ray: The study of crystal structure using X-RAY DIFFRACTION techniques. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Protein Conformation: The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).4-Quinolones: QUINOLONES containing a 4-oxo (a carbonyl in the para position to the nitrogen). They inhibit the A subunit of DNA GYRASE and are used as antimicrobials. Second generation 4-quinolones are also substituted with a 1-piperazinyl group at the 7-position and a fluorine at the 6-position.Quinolones: A group of derivatives of naphthyridine carboxylic acid, quinoline carboxylic acid, or NALIDIXIC ACID.Dermatitis, Phototoxic: A nonimmunologic, chemically induced type of photosensitivity producing a sometimes vesiculating dermatitis. It results in hyperpigmentation and desquamation of the light-exposed areas of the skin.Anti-Infective Agents: Substances that prevent infectious agents or organisms from spreading or kill infectious agents in order to prevent the spread of infection.Fluoroquinolones: A group of QUINOLONES with at least one fluorine atom and a piperazinyl group.Periodicals as Topic: A publication issued at stated, more or less regular, intervals.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.Streptomyces: A genus of bacteria that form a nonfragmented aerial mycelium. Many species have been identified with some being pathogenic. This genus is responsible for producing a majority of the ANTI-BACTERIAL AGENTS of practical value.Rhizophoraceae: A plant family of the order Rhizophorales, subclass Rosidae, class Magnoliopsida, that includes mangrove trees.Avicennia: A plant genus of the family Acanthaceae. Members contain NAPHTHOQUINONES. Black mangroves (common name for the genus) are distinguished from other mangroves by their spike-like aerial roots called pneumatophores that project from the soil or water surrounding the plants.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)Combretaceae: A plant family of the order Myrtales, subclass Rosidae, class Magnoliopsida. They are mostly trees and shrubs growing in warm areas.Vincamine: A major alkaloid of Vinca minor L., Apocynaceae. It has been used therapeutically as a vasodilator and antihypertensive agent, particularly in cerebrovascular disorders.Marketing: Activity involved in transfer of goods from producer to consumer or in the exchange of services.Research Report: Detailed account or statement or formal record of data resulting from empirical inquiry.Foundations: Organizations established by endowments with provision for future maintenance.Dietetics: The application of nutritional principles to regulation of the diet and feeding persons or groups of persons.Journalism, Medical: The collection, writing, and editing of current interest material on topics related to biomedicine for presentation through the mass media, including newspapers, magazines, radio, or television, usually for a public audience such as health care consumers.Publications: Copies of a work or document distributed to the public by sale, rental, lease, or lending. (From ALA Glossary of Library and Information Science, 1983, p181)Ligands: A molecule that binds to another molecule, used especially to refer to a small molecule that binds specifically to a larger molecule, e.g., an antigen binding to an antibody, a hormone or neurotransmitter binding to a receptor, or a substrate or allosteric effector binding to an enzyme. Ligands are also molecules that donate or accept a pair of electrons to form a coordinate covalent bond with the central metal atom of a coordination complex. (From Dorland, 27th ed)Reflex, Abdominal: Contractions of the abdominal muscles upon stimulation of the skin (superficial abdominal reflex) or tapping neighboring bony structures (deep abdominal reflex). The superficial reflex may be weak or absent, for example, after a stroke, a sign of upper (suprasegmental) motor neuron lesions. (Stedman, 25th ed & Best & Taylor's Physiological Basis of Medical Practice, 12th ed, p1073)Spectrophotometry, Infrared: Spectrophotometry in the infrared region, usually for the purpose of chemical analysis through measurement of absorption spectra associated with rotational and vibrational energy levels of molecules. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Cytosine: A pyrimidine base that is a fundamental unit of nucleic acids.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.Base Pairing: Pairing of purine and pyrimidine bases by HYDROGEN BONDING in double-stranded DNA or RNA.Carboxylic Acids: Organic compounds containing the carboxy group (-COOH). This group of compounds includes amino acids and fatty acids. Carboxylic acids can be saturated, unsaturated, or aromatic.tert-Butyl AlcoholEstersAmino Acids, Cyclic: A class of amino acids characterized by a closed ring structure.HydroquinonesPatents as Topic: Exclusive legal rights or privileges applied to inventions, plants, etc.ButanonesPentanols: Isomeric forms and derivatives of pentanol (C5H11OH).Inventions: A novel composition, device, or process, independently conceived de novo or derived from a pre-existing model.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.Estrenes: Unsaturated derivatives of the ESTRANES with methyl groups at carbon-13, with no carbon at carbon-10, and with no more than one carbon at carbon-17. They must contain one or more double bonds.Commerce: The interchange of goods or commodities, especially on a large scale, between different countries or between populations within the same country. It includes trade (the buying, selling, or exchanging of commodities, whether wholesale or retail) and business (the purchase and sale of goods to make a profit). (From Random House Unabridged Dictionary, 2d ed, p411, p2005 & p283)Taxes: Governmental levies on property, inheritance, gifts, etc.Prescription Fees: The charge levied on the consumer for drugs or therapy prescribed under written order of a physician or other health professional.Philately: Study of stamps or postal markings. It usually refers to the design and commemorative aspects of the stamp.Great BritainGermanyMedicine, Arabic: Traditional Arabic methods used in medicine in the ARAB WORLD.Magnetic Resonance Spectroscopy: Spectroscopic method of measuring the magnetic moment of elementary particles such as atomic nuclei, protons or electrons. It is employed in clinical applications such as NMR Tomography (MAGNETIC RESONANCE IMAGING).