RADioRioi.ofncAi, mi:c:hamsm at thk c;i:llular level 



-'Mii.i.KR, C. W. and Howard-Flanders, P. Metropolilan Vickers Electrical Co. Ltd. 

 CdZt'tte (1953) December 



"Saxon, G. Proc. phys. Soc. Lond. B 67 (1954) 705 



29BOAG, J. W., Dolphin, G. W. and Rotblat, J. Radiation Res. 9 (1958) 587 



3" Chance, B. Rev. sci. Imtrum. 22 (1951) 619 



3»BoAG, J. W. Minerva med., Paris (1957) 109 



32PANETH, F. and HoFEDiTZ, W. Ber. dtsch. chem. Ores. 62 (1929) 1335 



"Weiss. J. Xature. Lond. 153 (1944) 748 



3-« Walling, C. Free Radicals in Solution: _]ohn Wiley, New York. 1957 



3*Zavoisky, E. J. Ph's., Moscow 9 (1945) 211 



3«CoMBRissoN, J. and Uebersfeld, J. C. R. Acad. Sci., Paris 238 (1954) 1397 



s^GoRDY, W.,Ard, W. B. and Shields, H. Proc. nat. Acad. Sci., Wash., 41 (1955) 

 983 



38 Gordy, W. , Smith, W. V. and Trambarulo, R. Microwave Spectroscopy : John Wiley, 

 New York, 1953 



39 Ingram, D. J. E. Spectroscopy at Radio and Microwave Frequencies: Butterworths, 

 London. 1955 



•""Commoner, B., Heise, J. J. and Townsend, J. Proc. nat. Acad. Sci., Wash. 42 (1956) 

 710 



*> Conger. A. D., Randolph, M. L., Sheppard, C. W. and Luippold, H.J. Radia- 

 tion Res. 9 (1958) 525 



*2Hirshon, J. M. and Fraenkel, G. K. Rev. sci. Instrum. 26 (1955) 34 



«3Fraenkel, G. K. Ann. N.Y. Acad. Sci. 67 (1957) 546 



*^Zimmer. K. G., Ehrenberg, L. and Ehrenberg, A. Strahlentherapie 103 (1957) 1 



^^Zimmer, K. G. Radiation Res. Supplement 1 (1959) 463 



** Livingston. R. Radiation Res. Supplement 1 (1959) 463 



4' Smaller, B. and Avery. E. C. Nature, Lond. 183 (1959) 539 



^^Bennet, E. L., Calvin, M.. Holm-Hanson, O., Hucjhes, A. M.. Lonberg-Holm, 

 K. K., Moses, V. and Tolbert, B. M. Proceedings of the Second International Confer- 

 ence on the Peaceful Uses of Atomic Energy, Geneva, 1958 



"Laser. H. Radiation Res. 9 (1958) 142 



soBeringer. R. and Castle, J. G. Jr. Phys. Rev. 75 (1949) 1963 



siBeringer, R. and Castle, J. G. Jr. Phys. Rev. 81 (1951) 82 



"TiNKHAM, M. and Strandberg, M. W. P. Phys. Rev. 97 (1955) 937, 951 ; Phys. Rev. 



99 (1955) 537 

 ^^Eldjarn, L., Pihl, a. and Sh.apiro, B. Proceedings of the First International Conference 



on the Peaceful Uses of Atomic Energy, 11. Geneva, 1955. p. 335 

 ** Shields, H. and Gordy, W. Electron spin resonance studies of radiation damage to 



amino acids: Duke Microwave Laboratory publication. 1958 

 ^^Blumenfeld, L. a. and Kalmanson, A. E. Proceedings of the Second International 



Conference on the Peaceful Uses of Atomic Energy, Geneva. 1958 

 5« Powers, E. L., Webb, R. B. and Ehret, C. F. Cap. Cell. Res.— in the Press 



DISCUSSION 



Dr. Martin: If one alters the pulse length, presumably all that happens is that a 

 change in the slope of these oxygen and nitrogen curves occurs ? 



Dr. Gray: A lengthening of the pulse would prolong the time during which the cell 

 is devoid of oxygen but would not change the fraction of the dose given under 

 anaerobic conditions until the length of the pulse became comparable with the time 

 required for a significant amount of fresh oxygen to reach the required site. We 

 cannot conveniently change the length of our pulses, but we can give two pulses 

 separated by a variable interval. The use of double pulses would probably be a 



298 



