background: in this study we evaluated the incidence of hypothyroidism in patients who received external beam radiation due to cancer, when radiation portals included thyroid gland. methods: this prospective study was conducted from april 2004 to december 2005 among patients with head and neck or breast malignancies who referred to radiation oncology department of cancer institute, imam khomein...

The space environment is a complex, orbit dependent phenomenon. Regardless of orbit, the external surfaces of a spacecraft will be exposed to photons, charged particles and solid particles such as micrometeoroids. Vehicles in low earth orbit (LEO) must be designed to withstand additional environmental hazards such as hyper-velocity impacts by man-made orbital debris and erosion of external surf...

Skin ageing is a complex process that is determined by both intrinsic and extrinsic factors, which leads to a progressive loss of structure and function. There is extensive evidence indicating that oxidative stress induced by reactive oxygen species plays an important role in the process of human skin ageing. Mitochondria are the major source of cellular oxidative stress and are widely implicat...

background: since 1996 the assessment of environmental gamma radiation dose in residential areas of iranian towns and cities has been accomplished for 10 counties. as a practical method and based on the results of a pilot study, in order to attribute the final results to the whole residential area of a town five stations were selected for every town. the location of individual station was studi...

It is believed that a combination of environmental factors with mutagens induces carcinomas derived from thyroid follicular cells. In this study we tried to ascertain whether a single short-term exposure to external radiation is sufficient to induce thyroid carcinomas in rats under long-term high or low dietary iodine intake. Rats were tested over a period of 110 wk under high (approximately 10...

This study analyzes the thermal performance of solar thermal energy using double-pass absorber plate in Sanandaj, Iran. To this end, a mathematical model was encoded according to the energy and exergy balance equations and solved by MATLAB software. Given the environmental conditions and radiation intensity of a winter day in Sanandaj, the effects of external parameters such as radiation intens...