A hallmark of sun exposure is increased melanin synthesis by cutaneous melanocytes which protects against photodamage and photocarcinogenesis. Irradiation of human keratinocytes or melanocytes with ultraviolet (UV) rays stimulates the synthesis and release of alpha-melanotropin (alpha-MSH) and adrenocorticotropic hormone (ACTH), which induce cyclic AMP (cAMP) formation and increase the prolifer...

A brief review on the progress on in vivo studies of α-particle radiation effects using zebrafish embryos was given in this chapter. The zebrafish, Danio rerio, a small vertebrate from Southeast Asia, has become a preferred model for studying human disease. The main challenges of these α-particle radiobiological experiments included quantification of alpha-particle dose. In particular, speciall...

The variation of the alpha radioactivity in the air near the ground and the ground-level total gamma radiation has been monitored in North-eastern Greece over several days. Meteorological information regarding the temperature of the air and humidity has been simultaneously recorded. The alpha-radioactivity shows a periodic diurnal variation with a peak in the morning followed by a decrease in t...

Human erythrocytes were exposed to gamma-rays and alpha-particles to assess radiation-induced membrane damage and hemoglobin oxidation and denaturation. With all parameters measured, the alpha-particles proved to be less efficient than the gamma-rays. The time-dependence of hemolysis showed also clear differences: with the gamma-rays the process was faster, reaching saturation after 40-90 min (...

Radiation-induced cancer of bone, liver, and lung has been a prominent harmful side-effect of medical applications of alpha emitters. In recent years, however, the potential use of antibodies labeled with alpha emitting radionuclides against cancer has seemed promising because alpha particles are highly effective in cell killing. High close rates at high LET, effectiveness under hypoxic conditi...

this study aimed to evaluate the radiation safety condition and the level of radiation-awareness amongst staff and patients in 18 hospitals of shahid beheshti university of medical sciences, tehran, iran. this descriptive, cross–sectional study was administered to patients and personnel, also making a review on the radiation-safety status in the hospitals. in evaluating the level of awareness, ...

Unstable atomic nuclei may decay into less energetic nuclei by emission of alpha, beta, and gamma radiation. These forms of radiation are now known to consist of He4 nuclei, electron (or positron), and high energy photons respectively. Which types of decay a nuclei may undergo depends on how it is unstable. Many materials may emit more than one form of radiation. This is especially true when th...