Introduction: Radiation countermeasures are defined as use of an agent to minimize the deleterious effects of radiation therapy by administering the compound after the radiation exposure has occurred, regardless of toxicity. In spite of extensive study in this field, yet there is no suitable radioprotector introduced. In this study two naturally occurring antioxidants were stu...

Cosmic ray protons accelerated in the internal shocks of a long duration gamma ray burst can escape the fireball by converting to neutrons. Hadronic interactions of these neutrons inside a stellar wind bubble created by the progenitor star will produce TeV gamma rays via neutral meson decay and synchrotron radiation by charged pion-decay electrons in the wind magnetic field. Such gamma rays may...

We study the structure of an outer-magnetospheric gap around a rotating neutron star. Migratory electrons and positrons are accelerated by the electric field exerted in the gap and radiate copious gamma-rays via curvature process. Some of the gamma-rays materialize by colliding with the X-rays illuminating the gap, leading to a pair production cascade. The replenished charges partially screen t...

Radioresistant E. coli TGl harboring pUC 18 plasmid which was Ampicillin-resistant was exposed to 60Co gamma-rays or 3H beta-rays in saline to determine whether the relative biological effectiveness of 3H beta-rays is higher than one. After exposure to 60Co gamma-rays at a dose rate of 0.465 Gy/min, the D0 by colony formation was 145 Gy in the presence of Ampicillin in or absence from the agar ...

The gamma-ray imaging spectrometer (GRIS) we have assembled comprises four coaligned, independent imagers, each with its own detector and coded-aperture mask (Figure 1). Each detector “sees” incoming gamma rays only through its mask, which serves as the imaging optic for the gamma rays (see box, pp. 1819). This mask is mounted on a movable mask plate in front of the detector plane; moving the p...

background: prompt gamma neutron activation analysis (pgnaa) is known as a non-invasive technique capable of measuring elemental concentration in voluminous samples in a short period of time. also it is a valuable diagnostic tool for total body elemental measurements. 252cf and 241am-be sources which are usually used in this method, generate not only neutrons, but also emit high-energy and unwa...

This article reviews the present status of high energy γ-ray astronomy at energies above 30 MeV. Observations in the past decade using both spaceand ground-based experiments have been primarily responsible for giving a tremendous boost to our knowledge of the high energy Universe. High energy γ-rays have been detected from a wide range of Galactic and extragalactic astrophysical sources, such a...

background: this cross sectional study was conducted to evaluate the effect of &gamma-rays; and electron-beam irradiation with a commercial toxin binder-milbond-tx on the performance, feed components, and meat quality of japanese quails challenged with aflatoxin b1. methods: overall, 168 one-d-old chicks (japanese quails) were allocated to eight treatments with three replicates based on a compl...