aflatoxins are toxins which are usually produced by a kind of aspergillus fungus named flavus, parasiticus, and numius. there are 18 kinds of aflatoxins have been discovered by scientists and aflatoxin b1 is the most toxic and carcinogenic. taking aflatoxins present in food causes lots of diseases like liver diseases, alcoholic liver, mutagenesis, and malformation in animals. it also has some o...

abstract   background: the x-ray machines used for radiodiagnosis should meet certain quality assurance (qa) programmes . these are necessary to have good quality radiographs at reasonably low exposure to patients.   materials and methods: dose reduction methods in abdomen x-ray examination were carried out in 10 hospitals in tehran. this paper presents the work, which was implemented on 200 pa...

Introduction: Computed tomography is one of the most powerful tools for investigating thorax disease, because it shows progression of lung disease much clearer than chest radiography. Technical advances in CT scanners have led to some abilities for CT scanners such as coverage of larger volume, lower noise and ability for acquiring image in one respiratory phase. However, this will be accompani...

The principal objective of radiation protec­tion is to ensure that the dose received by any individual does not exceed the applicable M.P.D. values.We will discuss in this paper the presents recommendations and technical information related to the design and installation of struc­tural shielding with taking into account the concept of Maximum Permissible Dose equi­valent (MPDl as expressed and ...