background: the monte carlo method is the most accurate method for simulation of radiation therapy equipment. the linear accelerators are currently the most widely used machines in radiation therapy centers. methods: in this work, a monte carlo modelling of the siemens oncor linear accelerator in 6 mv and 18 mv beams was performed. the results of simulation were validated by measurements in wat...

introduction: the aim of this study was to compare the chemical compounds of white proroot mineral trioxide aggregate (wmta) hydrated at different ph environments. methods and materials: mixed samples of wmta were kept in acidic (ph=5.4), neutral (ph=7.4) and alkaline (ph=9.4) environments for 48 h. then, x-ray diffraction (xrd) analysis was performed for both hydrated and powder forms of wmta....

in spite of the technologies developed during the last decade, the level of food loss is still high and is reported in many countries. according to the united nations, more than 30 per cent of the mortality rate world-wide is caused by alimentary diseases. the desire of most countries to make food safer for consumption requires better food preservation and production techniques. in this regard,...

background: proper placement of central venous catheter (cvc) tip could reduce early and late catheter-related complications.although the live fluoroscopy is standard of care for placement of the catheter, it is not available in many centers. therefore, the present study evaluated the sensitivity and specificity of bedside chest x-ray (cxr) for proper positioning of the catheter tip. materials ...

conclusions this is the first case report of a vanishing tumor in the right pulmonary apex. case presentation such masses have been designated as vanishing tumors of the lung. it is extremely rare that a vanishing tumor occurs in the apex of the lung. introduction in patients with acute heart failure, pleural fluid localized in an inter-pleural fissure produces a mass on chest x-ray, which mimi...

oxide nanoparticles can exhibit unique physical and chemical properties due to their limited size and a high density of corner or edge surface sites. in this study, mgo nanoparticle was synthesized using mg(ch3coo)2 and hexamethylenetetramine as starting materials. the structure and optical properties of these particles are investigated by using x-ray diffraction (xrd), scanning electron micros...

the magnetite (fe3o4) – agar nanocomposite was prepared by co-precipitation of fe (iii) and fe (ii) ions for the first time. the obtained samples were characterized by x-ray diffraction, fourier-transform infrared spectroscopy, scanning electron microscopy and transmission electron microscopy. ft-ir results confirm the formation of fe3o4 nanoparticles in agar matrix. the xrd results revealed th...

conclusion according to our findings, ct-guided percutaneous drainage is a safe and effective procedure in the treatment of abdominal abscess and fluid collection. results the average age of the patients was 54 years (range 12 to 79), including 21 (51%) men and 20 (49%) women. the common signs and symptoms were pain (83%) and fever (80.5%). the most prevalent abdominal abscess etiology was prev...

background : the main objective of this research was to study photocatalytic oxidation of phenol in aquatic solutions by using of uv, tio 2 and the combination of them. phenol compounds are widely used in industries and other daily life. highly toxicity and carcinogenicity of these compounds can causal considerable adverse effects on the aquatic ecosystems and human health. methods : the study ...