A genus of SPONGES in the family Petrosiidae, characterized by an ectosomal triangular or polygonal reticulation of spicule tracts or single spicules.
Hydrocarbons with more than one triple bond; or an oxidized form of POLYENES. They can react with SULFUR to form THIOPHENES.
The phylum of sponges which are sessile, suspension-feeding, multicellular animals that utilize flagellated cells called choanocytes to circulate water. Most are hermaphroditic. They are probably an early evolutionary side branch that gave rise to no other group of animals. Except for about 150 freshwater species, sponges are marine animals. They are a source of ALKALOIDS; STEROLS; and other complex molecules useful in medicine and biological research.
A circumscribed melanosis consisting of a brown-pigmented, velvety verrucosity or fine papillomatosis appearing in the axillae and other body folds. It occurs in association with endocrine disorders, underlying malignancy, administration of certain drugs, or as in inherited disorder.
A series of heterocyclic compounds that are variously substituted in nature and are known also as purine bases. They include ADENINE and GUANINE, constituents of nucleic acids, as well as many alkaloids such as CAFFEINE and THEOPHYLLINE. Uric acid is the metabolic end product of purine metabolism.
A urea hydantoin that is found in URINE and PLANTS and is used in dermatological preparations.
The study of the origin, structure, development, growth, function, genetics, and reproduction of organisms which inhabit the OCEANS AND SEAS.
Compounds consisting of chains of AMINO ACIDS alternating with CARBOXYLIC ACIDS via ester and amide linkages. They are commonly cyclized.
A mass spectrometry technique using two (MS/MS) or more mass analyzers. With two in tandem, the precursor ions are mass-selected by a first mass analyzer, and focused into a collision region where they are then fragmented into product ions which are then characterized by a second mass analyzer. A variety of techniques are used to separate the compounds, ionize them, and introduce them to the first mass analyzer. For example, for in GC-MS/MS, GAS CHROMATOGRAPHY-MASS SPECTROMETRY is involved in separating relatively small compounds by GAS CHROMATOGRAPHY prior to injecting them into an ionization chamber for the mass selection.
A greenish-yellow, diatomic gas that is a member of the halogen family of elements. It has the atomic symbol Cl, atomic number 17, and atomic weight 70.906. It is a powerful irritant that can cause fatal pulmonary edema. Chlorine is used in manufacturing, as a reagent in synthetic chemistry, for water purification, and in the production of chlorinated lime, which is used in fabric bleaching.
A genus of SPONGES in the family Chalinidae characterized by unispicular secondary lines in the choanosomal skeleton.
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.
A physiochemical process which occurs in a wide range of organisms which unlike BASAL METABOLISM is not required for or essential to short-term survivability but to long-term general well-being of the organism.
Substances that reduce the growth or reproduction of BACTERIA.
The systematic study of the complete DNA sequences (GENOME) of organisms.
The fruiting 'heads' or 'caps' of FUNGI, which as a food item are familiarly known as MUSHROOMS, that contain the FUNGAL SPORES.
A non-taxonomic term for unicellular microscopic algae which are found in both freshwater and marine environments. Some authors consider DIATOMS; CYANOBACTERIA; HAPTOPHYTA; and DINOFLAGELLATES as part of microalgae, even though they are not algae.
A genus of SPONGES in the family Dysideidae, in which all skeletal fibers are filled with detritus.
A common name (but used formally) for a group of organisms that are mostly kinds of algae including BACILLARIOPHYTA; OOMYCETES; PHAEOPHYCEAE; and CHRYSOPHYCEAE. They all contain CHLOROPLASTS that are thought to have been derived from the endosymbiosis of ancient RED ALGAE.
The common name for the phylum of microscopic unicellular STRAMENOPILES. Most are aquatic, being found in fresh, brackish, and salt water. Diatoms are noted for the symmetry and sculpturing of their siliceous cell walls. They account for 40% of PHYTOPLANKTON, but not all diatoms are planktonic.
A genus of SPONGES in the family Axinellidae, comprised of a choanosomal skeleton differentiated in the axial and extra-axial region. The type species is Axinella polypoides.
Complex pharmaceutical substances, preparations, or matter derived from organisms usually obtained by biological methods or assay.
Individual's rights to obtain and use information collected or generated by others.
A quantitative measure of the frequency on average with which articles in a journal have been cited in a given period of time.
A publication issued at stated, more or less regular, intervals.
The evaluation by experts of the quality and pertinence of research or research proposals of other experts in the same field. Peer review is used by editors in deciding which submissions warrant publication, by granting agencies to determine which proposals should be funded, and by academic institutions in tenure decisions.
"The business or profession of the commercial production and issuance of literature" (Webster's 3d). It includes the publisher, publication processes, editing and editors. Production may be by conventional printing methods or by electronic publishing.
Substances that inhibit or prevent the proliferation of NEOPLASMS.
Software used to locate data or information stored in machine-readable form locally or at a distance such as an INTERNET site.
The use of statistical methods in the analysis of a body of literature to reveal the historical development of subject fields and patterns of authorship, publication, and use. Formerly called statistical bibliography. (from The ALA Glossary of Library and Information Science, 1983)
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.
Controlled vocabulary thesaurus produced by the NATIONAL LIBRARY OF MEDICINE. It consists of sets of terms naming descriptors in a hierarchical structure that permits searching at various levels of specificity.
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.
Compounds with two triple bonds. Some of them are CYTOTOXINS.
A large plant family in the order Apiales, also known as Umbelliferae. Most are aromatic herbs with alternate, feather-divided leaves that are sheathed at the base. The flowers often form a conspicuous flat-topped umbel. Each small individual flower is usually bisexual, with five sepals, five petals, and an enlarged disk at the base of the style. The fruits are ridged and are composed of two parts that split open at maturity.
Usually high-molecular-weight, straight-chain primary alcohols, but can also range from as few as 4 carbons, derived from natural fats and oils, including lauryl, stearyl, oleyl, and linoleyl alcohols. They are used in pharmaceuticals, cosmetics, detergents, plastics, and lube oils and in textile manufacture. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)
An araliaceous genus of plants that contains a number of pharmacologically active agents used as stimulants, sedatives, and tonics, especially in traditional medicine. Sometimes confused with Siberian ginseng (ELEUTHEROCOCCUS).
Hydrocarbons with more than one double bond. They are a reduced form of POLYYNES.
A group of atoms or molecules attached to other molecules or cellular structures and used in studying the properties of these molecules and structures. Radioactive DNA or RNA sequences are used in MOLECULAR GENETICS to detect the presence of a complementary sequence by NUCLEIC ACID HYBRIDIZATION.
Critical and exhaustive investigation or experimentation, having for its aim the discovery of new facts and their correct interpretation, the revision of accepted conclusions, theories, or laws in the light of newly discovered facts, or the practical application of such new or revised conclusions, theories, or laws. (Webster, 3d ed)
Those individuals engaged in research.
The complex series of phenomena, occurring between the end of one CELL DIVISION and the end of the next, by which cellular material is duplicated and then divided between two daughter cells. The cell cycle includes INTERPHASE, which includes G0 PHASE; G1 PHASE; S PHASE; and G2 PHASE, and CELL DIVISION PHASE.
Financial support of research activities.
Research that involves the application of the natural sciences, especially biology and physiology, to medicine.
The use of devices which use detector molecules to detect, investigate, or analyze other molecules, macromolecules, molecular aggregates, or organisms.
Community of tiny aquatic PLANTS and ANIMALS, and photosynthetic BACTERIA, that are either free-floating or suspended in the water, with little or no power of locomotion. They are divided into PHYTOPLANKTON and ZOOPLANKTON.
Hot springs on the ocean floor. They are commonly found near volcanically active places such as mid-oceanic ridges.
Devices, manned and unmanned, which are designed to be placed into an orbit about the Earth or into a trajectory to another celestial body. (NASA Thesaurus, 1988)
Minute free-floating animal organisms which live in practically all natural waters.
A great expanse of continuous bodies of salt water which together cover more than 70 percent of the earth's surface. Seas may be partially or entirely enclosed by land, and are smaller than the five oceans (Atlantic, Pacific, Indian, Arctic, and Antarctic).
Free-floating minute organisms that are photosynthetic. The term is non-taxonomic and refers to a lifestyle (energy utilization and motility), rather than a particular type of organism. Most, but not all, are unicellular algae. Important groups include DIATOMS; DINOFLAGELLATES; CYANOBACTERIA; CHLOROPHYTA; HAPTOPHYTA; CRYPTOMONADS; and silicoflagellates.