[Evaluating the effects of dual frequency sonication parameters on acoustic cavitation by chemical dosimeter using iodide]

Production of acoustic cavitation by sonication has been recently recommended as a targeted treatment. The experimental results from studies indicate that the activity of cavitation generated by bi- or multi-frequency ultrasound irradiation is higher than that caused by single frequency irradiation. In this study, effects dual [1 MHz and 40 kHz] and single frequency sonication on acoustic cavitation were investigated by chemical dosimeter using iodide. In this study, we investigated the exposure parameters in low level dual-frequency ultrasound in near fields of 40 kHz and 1 MHz in the progressive wave mode by chemical dosimeter using iodide. Finally, the effective protocol for enhancement of the inertial cavitation activity was determined. It has been shown that the dosimeter absorbance in the continuous mode sonication is more than the pulse mode. Moreover, significant correlations were found between the time and intensity of single and dual frequency sonication and the iodide dosimeter absorbance. In constant energy, inertial cavitation activity in the pulse mode remained approximately constant. Among different combinations, the combined ultrasound sonication in continuous mode could produce a more remarkable enhancement of the inertial cavitation activity [1.78 times] than the algebraic sum. Simultaneous combined dual frequency sonication is more effective than single frequency sonication in producing the inertial cavitation activity

[Relationship between occupational exposure and concentration of some trace elements in radiology and radiotherapy workers]

Investigating the chronic radiation effects in radiotherapy workers requires consideration of those parameters in which any small changes could result in profound effect on biological system. In this regard, body trace elements are believed to have important roles. To assess the biological effect of occupational exposure on blood trace elements concentrations. This was a case-control study performed at Isfahan University of Medical Sciences in 2006. Fifty radiotherapy workers were selected as case group and an equal number of hospital staff with similar social class and no radiation exposure as control group. Blood samples were collected from all members of two groups followed by determination of serum content of trace elements including copper, iron, zinc and magnesium. The data were analyzed using variance and regression tests. The mean concentrations of copper, iron, zinc and magnesium in technician group were 1.026 +/- 0.287, 1.052 +/- 0.185, 0.768 +/- 0.143, 21.112 +/- 1.272 and in control group 0.903 +/- 0.208, 1.00 +/- 0.134, 0.872 +/- 0.156, and 21.105 +/- 1.372, respectively. Values obtained for copper in technicians group were found to be higher than those of control group [p<0.02]. Zinc concentration was shown to be significantly lower in female technicians [p<0.03] than in males. No significant difference was found for magnesium or iron between two study groups. Based on data found in present study, the likelihood of the idea that chronic exposure to radiation could affect the concentration of body trace element is highlighted