| EXAFS | extended x-ray absorption fine structure |
|---|---|
| hfs | hyperfine structure |
| LFS | lateral facet syndrome; Li-Fraumeni syndrome; limbic forebrain structure; liver function series |
| MTS | Medicare transaction system; magnetization transfer contrast; methotrexate; multicellular tumor sphe... |
| QSAR | quantitative structure-activity relationship |
| soil structure | The combination or arrangement of primary soil particles into secondary particles, units or peds. (09 Oct 1997) |
|---|---|
| stem and loop structure | <molecular biology> The structure of tRNAs is so termed because it has four base paired stems and three loops (not base paired), one of which contains the anticodon. (18 Nov 1997) |
| structure | <microscopy> The mode of construction of an animate or inanimate body or system from units such as atoms, ions, molecules, cells, crystals in a fluid, plastic, or solid state. Cf. Morphology. (05 Aug 1998) |
| structure activity analysis | Study in which systematic variation in the structure of a compound is correlated with its activity, in an attempt to determine the characteristics of the (receptor) site at which it acts. (18 Nov 1997) |
| 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. Other factors contributing to structure-activity relationship include chemical reactivity, electronic effects, resonance, and inductive effects. (12 Dec 1998) |
| structure-functionalism | The scientific tradition that stresses the relationship between aphysical structure and its function, for example: the related disciplinesof anatomy and physiology. (09 Oct 1997) |
| structure proteins | Proteins whose role is for structure and support in tissue and within the cell; e.g., the collagens. (05 Mar 2000) |
| quarternary structure | The three-dimensional structure of a complex protein, this especially refers to the way the subunits fit together. (09 Oct 1997) |
| quaternary structure | The three-dimensional structure of a complex protein, this especially refers to the way the polypeptide subunits fit together. (09 Oct 1997) |
| tertiary structure | <biochemistry, chemistry> The third level of structural organisation in a macromolecule. The primary structure of a protein (for example) is the amino acid sequence, the secondary structure is the folding of the peptide chain (alpha helical or beta pleated), the tertiary structure is the way in which the helices or sheets are folded or arranged to give the three dimensional structure of the protein. Quaternary structure refers to the arrangement of protomers in a multimeric protein. (13 Jan 1998) |
| ecosystem structure | The physical and spatial aspects of an ecosystem that are contributed by the biotic composition. Biotic composition is generally determined by the collective physiognomy of the dominant plants, including life forms, vertical stratification, and size. (09 Oct 1997) |
| tuboreticular structure | Tubules 20-30 nm in length that lie within cisterns of smooth endoplasmic reticulum; observed in connective tissue diseases such as SLE, and in various cancers and virus infections. (05 Mar 2000) |
| fine structure | <pathology> General term to describe the level of organisation that is below the level of resolution of the light microscope. In practice, a shorthand term for structure observed using the electron microscope, although other techniques could give information about structure in the sub micrometre range. (18 Nov 1997) |
| fine structure mapping | A technique of DNA mapping which makes use of extremely rare recombination events where the crossing over occurs between two genes or two alleles of a gene that are only a few nucleotides apart. (09 Oct 1997) |
| aperture for electron microscopy | <technique> Anode aperture: The opening in the accelerating voltage anode shield of the electron gun through which the electrons must pass to irradiate the specimen. Condenser aperture: An opening in the condenser lens controlling the number of electrons entering the lens and the angular aperture of the electron beam. The angular aperture can also be controlled by the condenser lens current. Physical objective aperture: A metallic diaphragm, with a small central hole, used to limit the cone of electrons accepted by the objective lens. This improves image-contrast since highly scattered electrons are prevented from arriving at the Gaussian image plane and therefore cannot contribute to background fog. Aplanatic. Free from spherical aberration and coma. (05 Aug 1998) |