| SAO | small airway obstruction; splanchnic artery occlusion; subvalvular aortic obstruction |
|---|---|
| SB | Bachelor of Science; Schwartz-Bartter [syndrome]; serum bilirubin; shortness of breath; sick bay; si... |
| SBE | breast self-examination; short below-elbow [cast]; shortness of breath on exertion; small bowel enem... |
| SBFT | small bowel follow-through |
| SBO | small bowel obstruction; spina bifida occulta |
| nuclear layers of retina | The outer nuclear layer, layer 4, of the retina, neuroepithelial layer of retina, and the inner layer, layer 6, of the retina, ganglionic layer of retina. Synonym: granular layers of retina, stratum nucleare externum et internum retinae. (05 Mar 2000) |
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| nuclear localization signal | Short, predominantly basic amino acid sequences identified as nuclear import signals for some proteins. These sequences are believed to interact with specific receptors at nuclear pores. (12 Dec 1998) |
| nuclear magnetic resonance | Spectroscopic method of measuring the magnetic moment of atomic nuclei in a covalent bond. Clinical application is in biochemical, metabolic, and physiologic studies of living tissue. It includes proton and electron spin-echo and spin-relaxation times. (12 Dec 1998) |
| nuclear magnetic resonance, biomolecular | Nmr spectroscopy on small- to medium-size biological macromolecules. This is often used for structural investigation of proteins and nucleic acids, and often involves more than one isotope. (12 Dec 1998) |
| nuclear magnetic resonance imaging | A special imaging technique used to image internal stuctures of the body, particularly the soft tissues. An MRI image is often superior to a normal X-ray image. It uses the influence of a large magnet to polarize hydrogen atoms in the tissues and then monitors the summation of the spinning energies within living cells. Images are very clear and are particularly good for soft tissue, brain and spinal cord, joints and abdomen. These scans may be used for detecting some cancers or for following their progress. Acronym: MRI (11 Nov 1997) |
| nuclear magnetic resonance tomography | A special imaging technique used to image internal stuctures of the body, particularly the soft tissues. An MRI image is often superior to a normal X-ray image. It uses the influence of a large magnet to polarize hydrogen atoms in the tissues and then monitors the summation of the spinning energies within living cells. Images are very clear and are particularly good for soft tissue, brain and spinal cord, joints and abdomen. These scans may be used for detecting some cancers or for following their progress. Acronym: MRI (11 Nov 1997) |
| nuclear magneton | A constant in the equation relating the difference in energies between parallel and antiparallel spin alignments of atomic nuclei in a magnetic field; used in nuclear magnetic resonance spectrometry. (05 Mar 2000) |
| nuclear matrix | <cell biology> Membrane system that surrounds the nucleus of eukaryotic cells. Consists of inner and outer membranes separated by perinuclear space and perforated by nuclear pores. The term should be used in preference to the term nuclear membrane which is potentially very confusing. (18 Nov 1997) |
| nuclear medicine | <study> The branch of medicine pertaining to diagnostic, therapeutic and investigative use of radioactive chemical elements. (16 Dec 1997) |
| nuclear medicine department, hospital | Hospital department responsible for the administration and management of nuclear medicine services. (12 Dec 1998) |
| nuclear medicine physician | <specialist> A specialist trained in the interpretation and administration of diagnostic tests that use radionuclide compounds. (27 Sep 1997) |
| nuclear membrane | An intracellular structure, consisting of two concentric membranes, enclosing the nucleoplasm and separating it from the cytoplasm. The areas where these two membranes fuse are called nuclear pore complexes. (12 Dec 1998) |
| nuclear ophthalmoplegia | Ophthalmoplegia due to a lesion of the nuclei of origin of the motor nerves of the eye. (05 Mar 2000) |
| nuclear Overhauser effect | <enzyme> An enzyme seen in nuclear magnetic resonance in which there is a through-space nearest neighbor interaction. (05 Mar 2000) |
| nuclear pacemaker | A nuclear-powered unit used to generate the electrical current for artificially pacing the heart; replaced by units using long-life nickel-cadmium and other power sources. (05 Mar 2000) |