| secondary rays | X-ray's generated when primary X-ray's impinge upon matter; scattered radiation. (05 Mar 2000) |
|---|---|
| H rays | <physics> A stream of hydrogen nuclei; i.e., protons. (05 Mar 2000) |
| soft rays | X-ray's of relatively long wavelength and slight penetrability. (05 Mar 2000) |
| Niewenglowski rays | Radiation emitted from a phosphorescent body after exposure to sunlight. (05 Mar 2000) |
| supersonic rays | Ray's with a wavelength higher than that perceptible to the human ear, above 20,000 Hz. (05 Mar 2000) |
| direct rays | Cosmic ray's in the form in which they first strike the atmosphere, X-ray's generated at the focal spot of the tube. Synonym: direct rays. (05 Mar 2000) |
| Dorno rays | The ultraviolet ray's with wavelengths below 289 nm; those biologically active. (05 Mar 2000) |
| indirect rays | X-ray's generated at a surface other than the anode target. (05 Mar 2000) |
| infrared rays | That portion of the electromagnetic spectrum usually sensed as heat. Infrared wavelengths are longer than those of visible light, extending into the microwave frequencies. They are used therapeutically as heat, and also to warm food in restaurants. (12 Dec 1998) |
| intermediate rays | Those between ultraviolet and X-ray's. Synonym: W rays. (05 Mar 2000) |
| ultrasonic rays | See: ultrasonic. (05 Mar 2000) |
| ultraviolet rays | That portion of the electromagnetic spectrum immediately below the visible range and extending into the X-ray frequencies. The longer wavelengths (near-uv or biotic or vital rays) are necessary for the endogenous synthesis of vitamin d and are also called antirachitic rays; the shorter, ionizing wavelengths (far-uv or abiotic or extravital rays) are viricidal, bactericidal, mutagenic, and carcinogenic and are used as disinfectants. (12 Dec 1998) |
| CD4-positive T-lymphocytes | A critical subpopulation of regulatory T-lymphocytes involved in the induction of most immunological functions. The HIV virus has selective tropism for the t4 cell which expresses the CD4 phenotypic marker, a receptor for HIV. In fact, the key element in the profound immunosuppression seen in HIV infection is the depletion of this subset of T-lymphocytes, which includes both the helper-inducer (T-lymphocytes, helper-inducer) and suppressor-inducer (T-lymphocytes, suppressor-inducer) T-cells. (12 Dec 1998) |
| CD8-positive T-lymphocytes | A critical subpopulation of regulatory T-lymphocytes involved in MHC class I-restricted interactions. They include both cytotoxic T-lymphocytes (T-lymphocytes, cytotoxic) and suppressor T-lymphocytes (T-lymphocytes, suppressor-effector). (12 Dec 1998) |
| gram-positive | <microbiology> Bacteria that retain the stain or that are resistant to decolourisation by alcohol during Gram's method of staining. This is a primary characteristic of bacteria whose cell wall is composed of a thick layer of peptidologlycan containing teichoic and lipoteichoic acid complexed to the peptidoglycan. See: gram-negative (06 Oct 1997) |