Percent Inactivation Research Articles

Stability of penicillins in aqueous solutions I. Oxacillin and phenoxymethylpenicillin

Experimental data were obtained on the stability of phenoxymethylpenicillin and oxacillin in aqueous solutions with various pH values and at various temperatures. The antibiotics possess their maximum stability in the region of pH 6.0–7.0. Nomograms were compiled, permitting a determination of the percent inactivation of penicillins at any pH value and temperature within the indicated limits.

Über die Wirkung von β-Strahlen auf die Photosynthese-Phosphorylierung und die Hill-Reaktion isolierter Chloroplasten

Isolated spinach chloroplasts were exposed to ionising radiation (β-rays) from 90Sr. After irradiation photosynthetic-phosphorylation (PP) and Hill - reaction (HR) were checked and found to have high, but markedly different resistance. Dosis effect-curves were found indicating fifty percent inactivation of 130 000 rad (PP) or 530 000 rad (HR) respectively. There was no special effect of temperature on radiation resistance of the susceptible photosynthetic-phosphorylation. Results are discussed regarding their bearing upon the theory of radiation effects and upon the primary processes of photosynthesis.