| pitch angle scattering | <physics> Scattering (collisional, or due to wave-particle effects) of particles in velocity space, in which the pitch angle (see entry above) is changed. (09 Oct 1997) |
|---|---|
| Compton scattering | <radiobiology> An attenuation process observed for x and gamma radiation in which an incident photon interacts with an orbital electron of an atom to produce a recoil electron and a scattered photon of energy less than the incident photon. (16 Dec 1997) |
| scattering | <radiobiology> The deflection of one particle as a result of collisions with other particles or with waves. See: Elastic. (09 Oct 1997) |
| scattering, radiation | The process in which energy is removed from a beam of light or other electromagnetic radiation and emitted without appreciable change in wavelength. May be considered as the change in direction of a particle or photon owing to a collision with another particle or system. (12 Dec 1998) |
| Thomson scattering | <radiobiology> Scattering of photons by electrons, in the classical (low photon energy) limit. Laser light passed through a plasma will experience Thomson scattering, the spread of the scattered light in energy provides a very good measurement of the electron temperature of the plasma. (09 Oct 1997) |
| light scattering | Particles suspended in a solution will cause scattering of light and the extent of the scattering is related to the size and shape of the particles (in a somewhat complex relationship). (18 Nov 1997) |
| bilaterally small, smooth kidneys | <radiology> Generalised atherosclerosis, nephrosclerosis - benign and malignant, atheroembolic renal disease, chronic glomerulonephritis, papillary necrosis, hereditary diseases, hereditary chronic nephritis (Alport's syndrome), medullary cystic disease, amyloidosis (late), arterial hypotension Cf: other urographic patterns (12 Dec 1998) |
| carcinoma, non-small-cell lung | A heterogeneous aggregate of at least three distinct histological types of lung cancer, including squamous cell carcinoma, adenocarcinoma, and large cell carcinoma. They are dealt with collectively because of the shared properties of poor response to conventional chemotherapy and the potential for cure with surgical resection in a fraction of patients. (12 Dec 1998) |
| carcinoma, small cell | An anaplastic, highly malignant, and usually bronchogenic carcinoma composed of small ovoid cells with scanty neoplasm. It is characterised by a dominant, deeply basophilic nucleus, and absent or indistinct nucleoli. There are admixtures of small cell lung carcinoma with other types of lung cancer. Small cell carcinomas are distinguished by their distinctive biological features, response to chemotherapy and radiotherapy, and by their nearly universal tendency to develop overt or subclinical metastases, which frequently eliminates surgery in most patients. (12 Dec 1998) |
| generalised small bowel disease | <radiology> Hypoproteinaemia, sprue, Whipple (12 Dec 1998) |
| mesenteric portion of small intestine | The freely movable portion of the small intestine supplied with a mesentery, comprising the jejunum and ileum. Synonym: mesenteric portion of small intestine. (05 Mar 2000) |
| ribonucleoproteins, small nuclear | Highly conserved nuclear RNA-protein complexes that function in RNA processing in the nucleus, including pre-mRNA splicing and pre-mRNA 3'-end processing in the nucleoplasm. The u3 snrnp is localised in the nucleolus, where it aligns into base pairs with the 28s rrna precursor in a still unidentified region and functions in pre-rrna processing. The u7 snrnp aligns into base pairs with a conserved sequence in the 3'-end of histone pre-mRNA and is an essential cofactor for the cleavage that creates the mature nonadenylated 3'-end. (12 Dec 1998) |
| ribonucleoproteins, small, u1 | A nuclear RNA-protein complex that plays a role in RNA processing. In the nucleoplasm, the u1 snrnp along with other small ribonucleoproteins (u2, u4-u6, and u5) assemble into spliceosomes that remove introns from pre-mRNA by splicing. The u1 snrnp base pairs with conserved sequence motifs at the 5'-splice site and recognises both the 5'- and 3'-splice sites and may have a fundamental role in aligning the two sites for the splicing reaction. (12 Dec 1998) |
| ribonucleoproteins, small, u2 | A nuclear RNA-protein complex that plays a role in RNA processing. In the nucleoplasm, the u2 snrnp along with other small ribonucleoproteins (u1, u4-u6, and u5) assemble into spliceosomes that remove introns from pre-mRNA by splicing. The u2 snrnp base pairs with conserved sequence motifs at the branch point, which associates with a heat- and rnaase-sensitive factor in an early step of splicing. (12 Dec 1998) |
| ribonucleoproteins, small, u4-u6 | A nuclear RNA-protein complex that plays a role in RNA processing. In the nucleoplasm, the u4-u6 snrnp along with the u5 snrnp preassemble into a single 25s particle that binds to the u1 and u2 snrnps and the substrate to form mature spliceosomes. There is also evidence for the existence of individual u4 or u6 snrnps in addition to their organization as a u4-u6 snrnp. (12 Dec 1998) |