Roentgen (unit) Roentgen (unit) The roentgen or röntgen () (symbol R) is a legacy unit of measurement for the exposure of X-rays and gamma rays. It is defined as the electric charge freed by such radiation in a specified volume of air divided by the mass of that air. In 1928 it was the first international measurement quantity for ionising radiation to be defined for radiation protection, and was an easily replicated method of measuring air ionization directly by using an ion chamber. It is named after the German physicist Wilhelm Röntgen, who discovered X-rays. Although relatively easy to measure, it had
Sanford Burnham Prebys Medical Discovery Institute Sanford Burnham Prebys Medical Discovery Institute Sanford Burnham Prebys Medical Discovery Institute (SBP) is a non-profit medical research institute with locations in La Jolla, California, and Orlando, Florida. There are more than 850 scientists at SBP blending fundamental research with drug discovery to address unmet clinical needs in the areas of cancer, neuroscience, immunity, and metabolic disorders. Research at SBP is supported by funding from the National Institutes of Health, National Cancer Institute, and Juvenile Diabetes Research Foundation among others, and partnerships with pharmaceutical companies such as Johnson & Johnson Pharmaceutical Research and Development. In 2008, SBP was awarded a