Oxygen in space radiation biology
نویسنده
چکیده
Ionizing radiation at low LET is more effective in the presence of oxygen than in its absence in producing most biological effects. Most experimental radiobiological irradiations are conducted in the presence of oxygen at sufficient concentration to produce a “full oxygen effect”. To understand the full oxygen effect it is helpful to review the traditional definition of OER, which is the ratio of dose at reduced oxygen level to the dose in the presence of air to produce the same biological effect:
منابع مشابه
Induction of cancer stem-like cells in A549 cells after exposure to carbon ions and X-rays
Background: Cancer stem-like cells (CSCs) play a crucial role in the initiation, progression, and recurrence of cancer. Evidence indicates that the high linear energy transfer (LET) carbon ion beam is more effective against CSCs than the conventional X-ray beam. Carbon ion radiotherapy is considered as a promising cancer strategy, however, information about whether, or not, new CSCs are induced...
متن کاملPolyamines protect against radiation-induced oxidative stress.
Astronauts and cosmonauts are exposed to a wide variety of different hazards while in space that include radiation, which presents one of the most critical barriers to long-term missions. A major deleterious effect directly associated with ionizing radiation is the production of reactive oxygen species (ROS) such as peroxides and hydroxyl radicals. The free radicals generated by ultraviolet (UV...
متن کاملEvaluation of organs at risk dose in the left breast IOERT procedures whit and without shielding disc using monte carlo simulation
Introduction: One of the treatment choices in breast cancer is Intra operative electron beam radiation therapy (IOERT). Due to high dose delivery in this procedure, shielding disk is used to protect organs at risk (OARs). In this study, we evaluate the OARs dose in the breast IOERT using Monte Carlo simulation with and without shielding disk in RANDO phantom. Material and Methods: Simulation ...
متن کاملPoor Understanding of Radiation Profiles in Deep Space Causes Inaccurate Findings and Misleading Conclusions
The radiation environment in deep space, where astronauts are behind the shelter provided by the Earth’s magnetosphere, is a major health concern. Galactic cosmic rays (GCR) and solar particle events (SPE) are two basic sources of space radiation in the solar system. The health risks of exposure to high levels of space radiation can be observed either as acute and delayed effects. Zhang et al. ...
متن کاملDeep space missions and the issue of overcoming the problem of space radiation
As a member of the United Nations Committee on the Peaceful Uses of Outer Space (COPUOS), Iran has a long-term space exploration program. Space radiation is one of the challenges facing humans when they go outside Earth's protective atmosphere and magnetic field. Space is an environment that the cardinal principles of radiation protection i.e. time, distance and shielding cannot be effectively ...
متن کامل