| fusion | <radiobiology> A nuclear reaction in which light atomic nuclei combine to form heavier nuclei, typically accompanied by the release of energy. (See also Controlled Thermonuclear Fusion) (09 Oct 1997) |
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| fusion area | The area in and about the macula retinae in which stimulation of noncorresponding retinal points nevertheless results in stereoscopic vision. Synonym: fusion area. (05 Mar 2000) |
| fusion beat | A beat triggered by more than a single electrical impulse, when the wave fronts coincide to act together on a single final pathway of activity; in the electrocardiogram, the atrial or ventricular complex when either atria or ventricles are activated jointly by two simultaneous or nearly simultaneous invading impulses. Synonym: combination beat, mixed beat, summation beat. (05 Mar 2000) |
| fusion energy | <chemistry, radiobiology> The binding energy of a nucleus is the minimum energy required to dissociate it into its component neutrons and protons. Neutron or proton binding energies are those required to remove a neutron or proton, respectively, from a nucleus. Electron binding energy is that required to remove an electron from an atom or a molecule. (16 Dec 1997) |
| fusion gene | <molecular biology> A hybrid gene created by joining portions of two different genes (to produce a new protein) or by joining a gene to a different promoter (to alter or regulate gene transcription). (05 Jan 1998) |
| fusion protein | <protein> Protein formed by expression of a hybrid gene made by combining two gene sequences. Typically this is accomplished by cloning a cDNA into an expression vector in frame with an existing gene, perhaps encoding for example beta galactosidase. (18 Nov 1997) |
| fusion proteins, bcr-abl | Translation products of a fusion mRNA derived from the breakpoint cluster region (bcr) gene and a cellular abl (c-abl) gene translocated to chromosome 22. The p210(bcr-abl) fusion protein is found in patients with chronic myelogenous leukaemia. The p190(bcr-abl) fusion protein is found in patients with acute lymphocytic leukaemia. The activation of human c-abl by chromosomal translocation is essentially the same as the activation of murine c-abl by viral translocation in abelson murine leukaemia virus. (12 Dec 1998) |
| fusion proteins, gag-onc | General name for the translation products of a fusion mRNA consisting of a gag gene and a viral oncogene (v-onc). These products are thought to have the ability to transform cells. (12 Dec 1998) |
| fusion proteins, gag-pol | Polyprotein products of a fused portion of retroviral mRNA containing the gag and pol genes. The polyprotein is synthesised only five percent of the time since pol is out of frame with gag, and is generated by ribosomal frameshifting. (12 Dec 1998) |
| fusion reactor | <radiobiology> Device which creates energy in a controlled manner through fusion reactions. (09 Oct 1997) |
| fusion temperature | The recorded temperature at which a 20-gauge metal wire will collapse under a 3-ounce load; the recorded temperature at which porcelain becomes glazed. (05 Mar 2000) |
| fusion-fission hybrid | <radiobiology> Proposed nuclear reactor relying on both fusion and fission reactions. A central fusion chamber would produce neutrons to induce fission in a surrounding blanket of fissionable material. The neutron source could also be used to convert other materials into additional fissile fuels (breeder hybrid). Safer than a plain fission reactor because the fission fuel relies on the fusion neutrons, and therefore cannot achieve criticality. On the other hand, hybrids are more complex because of the fusion power core, and still generate fission's radioactive byproducts. But a fusion-fission hybrid could be more economical and have less stringent technical requirements than a pure fusion reactor. (05 Jan 1998) |
| fusion-inferred threshold test | Employment of the phenomenon of cerebral fusion of binaural sounds to substitute for conventional masking in hearing testing. Synonym: FIT test. (05 Mar 2000) |
| fusional movement | A reflex movement that tends to move the visual axes to the object of fixation so that stereoscopic vision is possible. (05 Mar 2000) |
| atrial fusion beat | A beat that occurs when the atria are activated in part by the sinus impulse and in part by an ectopic or retrograde impulse from A-V junction or ventricle. (05 Mar 2000) |
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| magnetic confinement fusion | <physics> Method of fusion which uses magnetic fields / magnetic bottles to confine a hot plasma until fusion occurs. (09 Oct 1997) |
| gene fusion | Fusion of structural genes to analyze protein behaviour or fusion of regulatory sequences with structural genes to determine mechanisms of regulation. (12 Dec 1998) |
| ventricular fusion beat | A fusion beat that occurs when the ventricles are activated partly by the descending sinus or A-V junctional impulse and partly by an ectopic ventricular impulse. (05 Mar 2000) |
| recombinant fusion proteins | Proteins that are the result of genetic engineering. A regulatory part or promoter of one or more genes is combined with a structural gene. The fusion protein is formed after transcription and translation of the fused gene. This type of fusion protein is used in the study of gene regulation or structure-activity relationships. They might also be used clinically as targeted toxins (immunotoxins). (12 Dec 1998) |
| vertebral fusion | A procedure that involves fusing together two or more vertebrae in the spine using either bone grafts or metal rods (Harrington rods). This procedure may be used to correct kyphosis or scoliosis. It is also used in those who require spine stabilisation due to vertebral damage from ruptures discs, fractures, osteomyelitis, osteoarthritis or tumour. (27 Sep 1997) |
| viral fusion proteins | Proteins, usually glycoproteins, found in the viral envelopes of a variety of viruses. They promote cell membrane fusion and thereby may function in the uptake of the virus by cells. (12 Dec 1998) |
| cell fusion | <biology, embryology> Fusion of two previously separate cells occurs naturally in fertilization and in the formation of vertebrate skeletal muscle, but can be induced artificially by the use of Sendai virus or fusogens such as polyethylene glycol. Fusion may be restricted to cytoplasm or nuclei may fuse as well. A cell formed by the fusion of dissimilar cells is often referred to as a heterokaryon. (26 Mar 1998) |
| centric fusion | <molecular biology> A special type of nonreciprocal translocation in chromosomes whereby the long arms of two nonhomologous acrocentric chromosomes are attached to a single centromere. The short arms become attached to form a reciprocal structure that however often disappears some divisions after its formation. (17 Dec 1997) |
| cervical fusion syndrome | <syndrome> Fused vertebrae, especially cervical spine (C3-C4), elevation of scapula (Sprengel deformity), omocervical bones, GU abnormalities (66%), renal agenesis (33%), deafness (33%) (12 Dec 1998) |
| cervical spine fusion | <radiology> (ankylosis) Posterior elements, JRA, vertebral bodies, block vertebrae, Klippel-Feil (12 Dec 1998) |
| membrane fusion | The adherence of cell membranes, intracellular membranes, or artifical membrane models of either to each other or to viruses, parasites, or interstitial particles through a variety of chemical and physical processes. (12 Dec 1998) |
| whole-arm fusion | <genetics, molecular biology> A break in the shortest arms of two acrocentric chromosomes followed by the fusion of the long arms into a single chromosome. (13 Nov 1997) |
| controlled thermonuclear fusion | <radiobiology> The process in which light nuclei, heated to a high temperature in a confined region, undergo fusion reactions under controlled conditions, with associated release of energy which may be harnessed for useful purposes. (09 Oct 1997) |
| critical flicker fusion frequency | The minimal number of flashes of light per second at which an intermittent light stimulus no longer stimulates a continuous visual sensation. (05 Mar 2000) |