1.   As a result, some have turned to beta radiation.

2.   Beta radiation can be blocked by wood or aluminum.

3.   Beta radiation causes the most damage if its particles are ingested or inhaled.

4.   Both Novoste Corp. and closely held Isostent Inc. have started human clinical trials in the U.S. using beta radiation.

5.   Researchers are still determining whether to use gamma radiation, which is used to kill cancer cells, or beta radiation, which is used by opthamologists.

6.   The companies are using different substances to produce the beta radiation.

7.   The study of beta radiation used a system made by Boston Scientific Corp. and was sponsored by the Prevot Foundation and the Swiss National Science Foundation.