| Autor: |
Kojima, T, Aihara, H, Kodashima, Y, Makishima, H, Nakiri, S, Takada, S, Shimada, H, Ukai, M, Ozga, C, Holzapfel, X, Schmidt, Ph, Küstner-Wetekam, C, Otto, H, Bloβ, D, Knie, A, Ehresmann, A, Yokoya, A, Fujii, K, Fukuda, Y, Saitoh, Y |
| Předmět: |
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| Zdroj: |
Radiation Protection Dosimetry; May2019, Vol. 183 Issue 1/2, p32-35, 4p |
| Abstrakt: |
To identify the precise molecular processes to induce DNA lesions, we attempt a novel spectroscopy of X-ray induced luminescence (XIL) using soft X-ray synchrotron radiation, which is a non-destructive analysis of the reaction intermediates in the elementary reaction pathway of damage induction and self-organized restoration. Using a liquid micro-jet technique to introduce aqueous samples in a vacuum chamber, we measure UV-visible luminescence from nucleotide solution as a function of the soft X-ray energy from the nitrogen to oxygen K-edge region. The XIL intensities for the nucleotide solutions are significantly enhanced in the soft X-ray region (410–530 eV) which is ascribed to the K-shell excitation/ionization of nitrogen atoms in the nucleobases. Furthermore, the XIL spectra do not show any signature of X-ray absorption near-edge structure (XANES) of the nucleobases. This is because the luminescence intensities collected from the integral area of the micro-jet only reflect the quantum yield of luminescence of the absorbed X-ray into UV-visible light irrespective of the absorption cross sections, i.e. of XANES. Thus the present result is the first evidence of luminescence as a result of X-ray absorption of aqueous nucleotides. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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