Environment in Space
Sources of Radiation in Space
Galactic Cosmic Rays
The Solar Wind
Coronal Mass Ejections
Radiation in Space
NASA research programs for
The International Space Station
Mission to Mars
Understand the biologica
Imaging: PET and SPECT
Positron Emission Tomography
Single Photon Emission Computed Tomography
PET and SPECT
Properties of ideal imaging nuclides, biological, chemical , physical
Production of radionuclides
Charged particle bombardment
Is there a 4th curve?
a term coined to describe the behavior of an agent that is lethal at high doses but
beneficial at low doses.
(e.g., nickel, chromium, hormones, ultraviolet light)
The radiation effects paradigm:
Radiation exposure is harmfu
Health Effects of Radiation
Effects of radiation on tissues are related to the functional organization of
Tissues are often organized into specialized cell types with limited ability to
This tissue unit is suppl
Cell Survival Curves
A cell that is able to proliferate indefinitely and form a large colony from a single
cell is said to be clonogenic.
Tumor cells can be grown indefinitely in cell culture.
Normal cells must be transformed to grow indefinite