Radiation action

Kellerer, A.M. and H.H. Rossi, The Theory of Dual Radiation Action, Current Topics Radiation Research. Quarterly. 8 85-158 (1972). 

Nonpolar Systems. Most of the early theoretical studies on radiation action were carried out on water and aqueous solutions. This was a consequence not only of Its Importance In radiation biology but also of the greater amount of experimental data and the simplicity of Its radiation chemical reactions as compared with organic systems. Recently, however, more studies on non-polar systems such as alkanes have appeared (24). It Is a long step to solid polymers but methods are being continually refined. 

Methimazole (Tapazole) [Antithyroid Agent] Uses Hyperthy-roidism, thyrotoxicosis, pr for thyroid surgery or radiation Action Blocks T3 T4 formation Dose Adults. Initial 15-60 mg/d PO tid Maint 5-15 mg PO daily Peds. Initial 0.4-0.7 mg/kg/24 h PO tid Maint V h- U h of initial dose PO daily w/ food Caution [D, +/-] Contra Breast-feeding Disp Tabs SE GI upset, dizziness, blood dyscrasias Interactions t Effects OF digitalis glycosides, metoprolol, propranolol X effects OF anticoagulants, theophylline X effects W/ amiodarone EMS None OD May cause N/V, HA, abd pain, fever, and pale skin symptomatic and supportive... 

The application of microdosimetry to medical physics derives from biological models of radiation action (primarily, the Theory of Dual Radiation Action [14]) that explicitly utilize for their predictions a microdosimetric description of the radiation field. Specifically, they concern the following two problems ... 

The dose-averaged specific energy z plays a fundamental role in microdosimetric-based models of radiation action. For instance, it will be shown below that its magnitude relative to D determines the extent to which dose-rate effects are important. If the micro-dosimetric spectrum /i(z) is known, z can be obtained by straightforward integration. There is, however, a second more powerful procedure for obtaining this quantity and this will be now explained. 

RADIOBIOLOGICAL CONSIDERATIONS 3.1. The Theory of Dual Radiation Action... 

Radiation Action, takes as starting point the empirical observation that for numerous effects, the yield of lesions (alterations responsible for the endpoint observed) depends quadratically on specific energy [14] ... 

Zaider, M. Dicello, J. RBEOER a Fortran program for the computation of RBEs, OERs, survival ratios and the effects of fractionation using the Theory of Dual Radiation Action. Los Alamos Scientific Laboratory Report LA-7196-MS, 1978 1-19. 

DNA s5mthesis and also interfere with cell replication. Alkylating agents has got cytotoxic action and damage the nuclei of growing and multiplying cells. They have got immunosuppressant action also and suppress antibody production. They also have radiomimetic (like ionizing radiation) actions. 

J. F. Ward, Mechanisms of radiation action on DNA in model systems - Their relevance to cellular DNA in The Early Effects of Radiation on DNA, ed. E. M. Fielden and P. O Neill, 1991, Springer-Verlag, 1-16. 

Action of Radiation. See Radiation Action Action Time of a Propellant in a Rocket. 

Laser (Light emission by stimulated emission of radiation), action, with its tremendous phase coherence (Rayleigh scattering), was discovered much later, in 1960 (Section 10.10), but provision for it already existed in Einstein s analysis ... 

Fig. 1 The stages of radiation action on chemical systems and biological organisms.

DNA is considered as one of the plausible critical targets for radiation action because there is only one or a few copies of the genome in each cell, because it is large compared with other molecular components, and because it plays a critical role in the proliferation and survival of the cell. 

N. Miller, in Introduction h la Dosimetrie des Radiations, Actions chimique et biologiques des Radiations, M. Haissinsky, ed., Masson et Cie, Paris, France, 1956. 

---