Separation of a mixture in successive stages, each stage removing from the mixture some proportion of one of the substances, for example by differential solubility in water-solvent mixtures. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Techniques to partition various components of the cell into SUBCELLULAR FRACTIONS.
Separation of molecules and particles by a simultaneous action of carrier liquid flow and focusing field forces (electrical, sedimentation, or thermal), without a stationary phase.
Components of a cell produced by various separation techniques which, though they disrupt the delicate anatomy of a cell, preserve the structure and physiology of its functioning constituents for biochemical and ultrastructural analysis. (From Alberts et al., Molecular Biology of the Cell, 2d ed, p163)
The composition, conformation, and properties of atoms and molecules, and their reaction and interaction processes.
The sum of the weight of all the atoms in a molecule.
Theoretical representations that simulate the behavior or activity of chemical processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.
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.
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).
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
The rate dynamics in chemical or physical systems.
Methodologies used for the isolation, identification, detection, and quantitation of chemical substances.
Techniques used to separate mixtures of substances based on differences in the relative affinities of the substances for mobile and stationary phases. A mobile phase (fluid or gas) passes through a column containing a stationary phase of porous solid or liquid coated on a solid support. Usage is both analytical for small amounts and preparative for bulk amounts.
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.
An acquired disorder characterized by recurrent symptoms, referable to multiple organ systems, occurring in response to demonstrable exposure to many chemically unrelated compounds at doses below those established in the general population to cause harmful effects. (Cullen MR. The worker with multiple chemical sensitivities: an overview. Occup Med 1987;2(4):655-61)
Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.
The systematic study of the complete complement of proteins (PROTEOME) of organisms.
Measurable and quantifiable biological parameters (e.g., specific enzyme concentration, specific hormone concentration, specific gene phenotype distribution in a population, presence of biological substances) which serve as indices for health- and physiology-related assessments, such as disease risk, psychiatric disorders, environmental exposure and its effects, disease diagnosis, metabolic processes, substance abuse, pregnancy, cell line development, epidemiologic studies, etc.
An analytical method used in determining the identity of a chemical based on its mass using mass analyzers/mass spectrometers.
Separation technique in which the stationary phase consists of ion exchange resins. The resins contain loosely held small ions that easily exchange places with other small ions of like charge present in solutions washed over the resins.
Chromatographic techniques in which the mobile phase is a liquid.
A prediction of the probable outcome of a disease based on a individual's condition and the usual course of the disease as seen in similar situations.
Administration of the total dose of radiation (RADIATION DOSAGE) in parts, at timed intervals.
The profession of writing. Also the identity of the writer as the creator of a literary production.
The relationship between the dose of administered radiation and the response of the organism or tissue to the radiation.
Collections of facts, assumptions, beliefs, and heuristics that are used in combination with databases to achieve desired results, such as a diagnosis, an interpretation, or a solution to a problem (From McGraw Hill Dictionary of Scientific and Technical Terms, 6th ed).
The guidelines and policy statements set forth by the editor(s) or editorial board of a publication.
Intentional falsification of scientific data by presentation of fraudulent or incomplete or uncorroborated findings as scientific fact.
"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.
Books used in the study of a subject that contain a systematic presentation of the principles and vocabulary of a subject.
That portion of the electromagnetic spectrum from the UHF (ultrahigh frequency) radio waves and extending into the INFRARED RAYS frequencies.
The resistance to the flow of either alternating or direct electrical current.
Recording changes in electrical impedance between electrodes placed on opposite sides of a part of the body, as a measure of volume changes in the path of the current. (Stedman, 25th ed)
The ability of a substrate to retain an electrical charge.
The aggregation of suspended solids into larger clumps.
Characteristics of ELECTRICITY and magnetism such as charged particles and the properties and behavior of charged particles, and other phenomena related to or associated with electromagnetism.
The formation of crystalline substances from solutions or melts. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
A vinyl polymer made from ethylene. It can be branched or linear. Branched or low-density polyethylene is tough and pliable but not to the same degree as linear polyethylene. Linear or high-density polyethylene has a greater hardness and tensile strength. Polyethylene is used in a variety of products, including implants and prostheses.
Synthetic thermoplastics that are tough, flexible, inert, and resistant to chemicals and electrical current. They are often used as biocompatible materials for prostheses and implants.
Polymers of ETHYLENE OXIDE and water, and their ethers. They vary in consistency from liquid to solid depending on the molecular weight indicated by a number following the name. They are used as SURFACTANTS, dispersing agents, solvents, ointment and suppository bases, vehicles, and tablet excipients. Some specific groups are NONOXYNOLS, OCTOXYNOLS, and POLOXAMERS.
Endogenous factors or drugs that increase the transport and metabolism of LIPIDS including the synthesis of LIPOPROTEINS by the LIVER and their uptake by extrahepatic tissues.
The study of crystal structure using X-RAY DIFFRACTION techniques. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Oils which evaporate readily. The volatile oils occur in aromatic plants, to which they give odor and other characteristics. Most volatile oils consist of a mixture of two or more TERPENES or of a mixture of an eleoptene (the more volatile constituent of a volatile oil) with a stearopten (the more solid constituent). The synonym essential oils refers to the essence of a plant, as its perfume or scent, and not to its indispensability.