1981年 · 第01卷第04期

By means of a water-filled phantom the detective efficiency of a shadow-shield whole-body counter was calibrated.

The efficiency curves for different ratio of the weight and height of the body with different energies of γ-quantum under three conditions were obtained and compared with those of the "reference man" phantom. In additon, a controlled variable speed scanning method was recommended, which might improve the uniformity of the space response and reduce the effect of uniformity of the distribution of radionuclide in body, and hence the accuracy of the measurement was improved.

It has been shown that the muscular conditioned medium (MCM) is rich in colony stimulating factor. Its effect is species specific. The mouse MCM can be inactivated by ethyl ester. More than 70% colonies produced by mouse MCM are of loose diffusive type. On the contrary, the activity of human MCM is only slightly inhibited by ethyl ester and about 66% colonies formed by human MCM appear to be dense and compact. The doubling time for the multiplication of mouse bone marrow cells is 10.6 hours while that for human cells is 23.6 hours.