Relative biological efficiency

The effective biological dose (Ee 18) at local apparent noon for each chamber was estimated by multiplying the relative biological efficiency for photoinhibition [epi(X)] by the available spectral irradiance [E(X)], and integrating with respect to wavelength (X, 290-400 nm) ... 

Vulpis (1973) added pure natural boron as H3B03, which contains about 19% B-10, to the blood culture. It was then irradiated with thermal neutrons from a reactor. The reaction of B-10(n,a)Li-7 within the culture served as alpha source. The dose range was 35 to 195 mGy according to her dose estimation which was complicated by subtracting the dose due to the reactor radiation alone. The dicentric chromosomes appeared to follow a linear response up to about 0.18 Gy and then leveled off to a plateau due to a "saturation effect. The relative biological efficiency (RBE) with respect to X-rays with the doses up to 5f1 Gy was found to be 23. v... 

Proton-coupled electron transfer Relative biological efficiency Ribonucleic acid Any thiol... 

It is now usual to calculate the effective dose equivalent (Appendix 1.2). The dose equivalent measured in Sieverts (Sv), takes into account the relative biological efficiency of different radiations. For gamma and beta radiation, the conversion factor is unity, but for alpha radiation it is 20. The effective dose equivalent allows also for the relative importance of irradiation of various organs to the risk of cancer. To convert thyroid dose from beta particles, measured in Gy, to effective dose equivalent, a factor 0.03 is applied. Thus the maximum thyroid doses estimated by Loutit et al. correspond to effective dose equivalents of 4.8 mSv (child) and 1.2 mSv (adult). Adding the external whole body gamma radiation, for which the conversion factor is unity, gives 5.4 mSv (child) and 1.8 mSv (adult). 

D. R. Davies and J. L. Bateman, A high relative biological efficiency of 650-keV neutrons and 250-kVp x-rays in somatic mutation induction. Nature 200,485-486 (1963). 

D. R. Davies, A. H. Sparrow, R. G. Woodley, and A. Maschke, Relative biological efficiency of negative //-mesons and cobalt-60 y-rays. Nature 200, 277-278 (1963). 

Conclusions drawn from in vitro cell studies with heavy ion beams of varying LET have indicated that approximately 100 keV /tm" was optimal in achieving a maximum relative biological effect (R6E), as demonstrated by the blocking of cells in Gj -1- M and subsequent lethal effects (21,96,97). The efficient arrest of cultured human squamous cell carcinoma of the larynx (HEp2) and murine rectal adenocarcinoma... 

Relative Biological Value calculated by dividing the efficiency of converting iron from the test diets into hemoglobin iron relative to that for diets containing ferrous. sulfate. 

Different kinds of radiation have different ionization efficiencies and are absorbed in different ways. In order to compensate for this the unit rem ( roentgen equivalent, man ) was introduced. It is defined as the quantity of radiation of any type which produces the same biological effect in man as that produced by 1 r of X-ray or y ray radiation. However, the biological effect depends upon the part of the body irradiated and on the type of radiation. This problem is dealt with by estimating a relative biological effectiveness (RBB), in relation to y-rays, for various parts of the body. For example, as far as the production of cataracts is concerned, 1 rad of fast neutrons is ten times as effective as 1 rad of y-rays. Thus if the eyes were... 

The major advantages of EWs are their relatively low toxicity when compared with ECs, their high flash points and possibility of incorporation of adjuvants in the oil and aqueous phases. In addition, by controlling the droplet size distribution of the oil, one can enhance deposition and spreading and this may increase biological efficiency. 

Thus, bench or pilot studies are necessary to avoid technology misapplication in the field. The loss of time in treatment or the requirement to provide additional treatment for the waste is very expensive. Therefore, the relatively small costs and time needed for these studies make them useful tools in treatment selection. Bench-scale treatability studies for demonstrated technologies can cost between 10,000- 50,000 and take up to 6 weeks. Demonstrated technologies are those for which the major design parameters and treatment efficiencies are well understood. Innovative (and some biological processes) will require substantially more time (4-16 weeks) and money ( 25,000-> 200,000). These are estimates, and actual time and costs are going to depend on what kind of technology is under consideration. 

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