Between Ultraviolet and Ionizing Radiation: Action Spectra for Cytotoxicity in the Vacuum-UV Region
Like UV-C, vacuum-UV is strongly absorbed by oxygen, so it does not reach the surface of the earth as in the case of UV-C. The vacuum-UV below 180 nm is strongly absorbed by water. This property is an important difference from UV-C. DNA as well as proteins show the first absorption peak in the vacuum-UV region around 190 nm attributable to the double bonds. For DNA such absorption is due to the π electron system of the bases. In the shorter wavelengths the absorption may be attributed largely to the sugar-phosphate moiety. The σ-σ* transition is generally thought to be responsible. Depending on the wavelength (or photon energy) the molecule may be promoted to the higher excited states (Kiseleva et al., 1975; Ito and Ito, 1986).
KeywordsAttenuation Bacillus Streptomyces Photolysis Saccharomyces
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- Ito, A., and Ito, T., Absorption spectra of deoxyribose, ribosephosphate. ATP and DNA by direct transmission measurements in the vacuum-UV (155–190 nm) and far-UV (190–260 nm) regions using synchrotron radiation as a light source. Photochemistry and Photobiology, 44, 355–358, 1986.PubMedCrossRefGoogle Scholar
- Ito, T., Kada, T., Okada, S., Hieda, K., Kobayashi, K., Maezawa, H., and Ito, A., Synchrotron system for monochromatic UV irradiation (>140 nm) of biological material. Radiation Research, 98, 65–73, 1984.Google Scholar
- Kiseleva, M.M., Zarochensteva, Ye. P., and Dodonova, N.Ya., Absorption spectra of nucleic acids and related compounds in the spectral region 120–280 nm. Biophysics (Biofizika), 20, 571–575, 1975.Google Scholar
- Maezawa, H., Ito, T., Hieda, K., Kobayashi, K., Ito, A., Mori, T. and Suzuki, K., Action spectra for inactivation of dry phage T1 after monochromatic (150–254 nm) synchrotron irradiation in the presence and absence of photoreactivation and dark repair. Radiation Research, 98, 227–233, 1984.PubMedCrossRefGoogle Scholar
- Munakata, N., Vacuum-UV action spectra for inactivation of Bacillus subtilis spores. Activity Report of Synchrotron Radiation Laboratory, Institute for Solid State Physics, University of Tokyo, pp. 76–77, 1986.Google Scholar
- Platzma, R.L., Energy spectrum of primary activation in the action of ionizing radiation, in: Radiation Research. Ed. G. Silini, pp. 20–42, North-Holland, Amsterdam, 1967.Google Scholar