background: megavoltage beams used in radiotherapy are contaminated with secondary electrons. different parts of linac head and air above patient act as a source of this contamination. this contamination can increase damage to skin and subcutaneous tissue during radiotherapy.  monte carlo simulation is an accurate method for dose calculation in medical dosimetry and has an important role in opt...

background: interventional cardiology procedures such as coronary angiography (ca) and percutaneous transluminal coronary angiography (ptca) has been increased recent years. the purpose of this study was to measurement of effective dose to cardiology staffs who operate near the patient and are exposed to non-uniform radiation field due to patient scattered radiation. materials and methods: this...

Sex differentiation of gonads in amphibians is believed to be controlled genetically, but altered epigenetically or environmentally. When larvae of the salamander Hynobius retardatus were reared at defined temperatures from hatching to metamorphic stages, a high temperature (28 degrees C) induced exclusively female gonads (ovaries), whereas intermediate (20 and 23 degrees C) or lower (16 degree...

undesired radiation exposure to caregivers is an important problem in radioiodine therapy in thyroid carcinoma patients, especially when patient is non-ambulatory. special precautions are needed to keep the exposure to caregivers low when higher dose of radioiodine is necessary. here we present a case-report of a 74-year old male patient with papillary thyroid carcinoma with local invasion and ...

4-Nonylphenol (NP) is a surfactant that is a well-known and widespread estrogenic endocrine disrupting chemical (EDC). Although it has been known that the affinity of NP to ERs is low, it has been suggested that low-dose NP has toxicity. In the present study, the endocrine disrupting effects on reproduction, and the weight of gonads, epididymis, and uterus were evaluated with the chronic lower-...

background: although some patients can tolerate colonoscopy procedure using fentanyl/ midazolam without any sedation and analgesic requirements but some patients may require additional sedation with benzodiazepines. we performed the present study to compare the effect of paracetamol/midazolam with fentanyl/ midazolam. methods: in a clinical trial, 96 patients aged 18 to 75 years old, who were c...

background: hdr brachytherapy is one of the commonest methods of nasopharyngeal cancer treatment. in this method, depending on how advanced one tumor is, 2 to 6 gy dose as intracavitary brachytherapy is prescribed. due to high dose rate and tumor location, accuracy evaluation of treatment planning system (tps) is particularly important. common methods used in tps dosimetry are based on computat...