background: bisphosphonates (bps) are used extensively for managing the osteoporosis. there are some controversies on atypical fractures of femur that associated with increase in cortical thickness (ct) and bps' use. in this study, the effects of alendronate consumption were studied on femoral ct as a predictor for atypical fracture.   methods: forty nine post-menopausal women aged 50-70 years ...

background: in diagnostic radiology there are two reasons for measuring or estimating radiation doses to patients. firstly measurements provide a means for setting and checking standards of good practice as an aid to the optimization of patient protection. secondly estimates of the absorbed dose to tissue and organs in the patients. materials and methods: a total of 2382 patients were studied t...

We used a high flux synchrotron X-ray beam to map the structure of 16S rRNA and RNase P in viable bacteria in situ. A 300 ms exposure to the X-ray beam was sufficient for optimal cleavage of the phosphodiester backbone. The in vivo footprints of the 16S rRNA in frozen cells were similar to those obtained in vitro and were consistent with the predicted accessibility of the RNA backbone to hydrox...

clay minerals are considered the most important components of clastic reservoir rock evaluation studies. the shurijeh gas reservoir formation, represented by shaly sandstones of the late jurassic-early cretaceous age, is the main reservoir rock in the eastern kopet-dagh sedimentary basin, ne iran. in this study, x-ray diffraction (xrd), x-ray fluorescence (xrf), scanning electron microscopic (s...

Introduction: Crosstalk is a leakage of X-ray or light produced in a matrix of X-ray detectors or array of photodiodes in one element to other elements affecting on image contrast and spatial resolution. In this study, we assessed X-ray crosstalk in a computed tomography (CT) scanner with small detector elements to estimate the effect of various parameters such as X-ray tube voltage, detector e...

Introduction Radiation exposures from diagnostic medical examinations are generally low and are almost always justified by the benefits of accurate diagnosis of possible disease conditions. Therefore, entrance skin dose (ESD), body organ dose (BOD), and effective dose (ED) from adult patients undergoing routine thorax posterior-anterior (PA) and thorax right lateral (RLAT) were estimated in Uni...

Background: Panoramic imaging is one of the most common imaging methods in dentistry. Regarding the side-effects of ionizing radiation, it is necessary to survey different aspects and details of panoramic imaging. In this study, we compared the absorbed x-ray dose around two panoramic x-ray units: PM 2002 CC Proline (Planmeca, Helsinki, Finland) and Cranex Tome (Soredex, Helsinki, Finland).<br ...