purpose: to determine the prevalence of refractive errors in the students of mashhad university of medical sciences, iran methods: in this cross-sectional study, we used cluster sampling for selecting participants from every department of mashhad university of medical sciences, proportional to the number of students in each department. each participant received refraction examination with an au...

introduction: it is a common protocol to use 201tl for the rest and 99mtc for the stress cardiac spect imaging. theoretically, both types of imaging may be performed simultaneously using different energy windows for each radionuclide. however, a potential limitation is the cross-contamination of scattered photons from 99mtc and collimator x-rays into the 201tl energy window. we used a middle en...

purpose: to determine the prevalence of uncorrected refractive errors and its determinants in tehran in 2002. methods: a total of 6497 citizens representing a cross-section of the population of tehran were sampled using a stratified random cluster sampling strategy. of these, 4565 (70.3%) subjects participated in the study and were transferred to a clinic for an extensive eye examination and in...

avian infectious bronchitis (ib) is a widely distributed poultry disease that has huge economic impact on poultry industry. the continuous emergence of new ibv genotypes and lack of cross protection among different ibv genotypes have been an important challenge. the present study was done to evaluate protection caused by two different serotypes’ vaccines (massachusetts & 793/b) in order to eval...

background legionellaceae contains legionella genus with over 52 species and 64 serogroups. it is one of the most important causes of respiratory disease in human. more than 30% of hospital-acquired pneumonia is caused by legionella. ventilator-associated pneumonia (vap) is an infection acquired in hospital wards, particularly in intensive care unit (icu). this disease approximately affects 9% ...

BENCHMARKS Conditional gene expression using the Tet system is well established in eukaryotes (1). The tetracycline-controlled transactivator (tTA) binds to P tet-1 in the absence of an effector and stimulates transcription of the successive target gene (2). Effector tet-racyclines abolish activation by tTA (Tet-Off). The reverse transactivator rtTA2 S-M2 contains a mutated tetR al-lele and act...

Considering the importance of validation of customers in the cross-dock and since this is one of the problems of implementing cross-dock system in Iran, this study attempted to extract customer validation criteria. The purpose of the research is to eliminate the distrust of distributors in receiving the funds of the sent items and the statistical sample of this research is the experts of the sy...