Differentiation is an epigenetic process which is installed by changes of transcriptional programs over successive cellular divisions. A number of studies have reported the effects of biochemical modifications of chromatin (DNA and chromatin proteins) on the regulation of transcription. Although, these studies are able to explain how transcription of a given gene is regulated (toward activation...

Annually, many people are irradiated for diagnostic and therapeutic purposes. Assessment of radiation dose and its related risks to patients are important issues in radiation protection dosimetry. The complex mathematical calculations of the absorbed and effective doses are now done with computers. The calculations are performed with the help of anthropomorphic computational models of human bod...

over the past few decades, actin’s presence in the nucleus has been demonstrated. actin is a key protein necessary for different nuclear processes. although actin is well known for its functional role in dynamic behavior of the cytoskeleton, emerging studies are now highlighting new roles for actin. at the present time there is no doubt about the presence of actin in the nucleus. a number of st...

abstract  background: the essential constituents of cements like lime, silica and alumina are derived from earth’s crust in which radioactive elements like uranium, thorium etc are also present in varying amounts almost everywhere. these two elements are considered as the parent elements of uranium and thorium radioactive decay series in which radon and thoron are produced respectively as decay...

flow cytometry (fcm) was used to determine the ploidy levels of six different populationsof agropyron cristatum (l.) gaertn. (poaceae) in iran, using a diploid cultivated barley (hordeumvulgare l.) as an internal reference. according to flow cytometric data, tetraploid (2n = ± 28) andhexaploid (2n = ± 42) levels were detected among the examined populations and these results weresupported by chr...

introduction radiofrequency planar microcoils are used to increase the resolution of magnetic resonance images of small samples. in this study, we aimed to design and fabricate a spiral planar microcoil constructed on a double-sided printed circuit board (pcb). it has four rings with an internal diameter of 241 microns tuned and matched at 63.8 mhz. materials and methods to achieve the maximum ...

background: ct scan and nuclear medicine exams deliver a great part of medical exposures. this study examined professional radiation hazards in ct scan and nuclear medicine workers.   methods : in a cross sectional study 30 occupationally exposed workers and 7 controls (all from personnel of a laboratory) were selected. physical dosimetry was performed for exposed workers. blood samples were ob...