Search results
Results from the WOW.Com Content Network
For example, the median lethal dose (LD-50) for ingested polonium-210 is 240 μCi; about 53.5 nanograms. The typical human body contains roughly 0.1 μCi (14 mg) of naturally occurring potassium-40. A human body containing 16 kg (35 lb) of carbon (see Composition of the human body) would also have about 24 nanograms or 0.1 μCi of carbon-14 ...
Retinol, also called vitamin A 1, is a fat-soluble vitamin in the vitamin A family that is found in food and used as a dietary supplement. [3] Retinol or other forms of vitamin A are needed for vision, cellular development, maintenance of skin and mucous membranes, immune function and reproductive development. [3]
A 39 nanograms/mL peak serum concentration of methylphenidate has been found to occur between 7.5–10.5 hours after administration. [77] However, the onset to peak effect is 2 hours, and the clinical effects remain up to 2 hours after the patch has been removed.
One gram of uranium (in radioactive equilibrium) contains only 2 × 10 −10 gram of 227 Ac. [30] [57] Actinium-228 is a member of the radioactive thorium series formed by the decay of 228 Ra; [60] it is a β − emitter with a half-life of 6.15 hours. In one tonne of thorium there is 5 × 10 −8 gram of 228 Ac. It was discovered by Otto Hahn ...