pharmaceutical products prepared in pharmacies have the potential of contamination with different microorganisms. this is in part due to the unhygienic environment and also lack of a suitable preservative system. in this study, microbial quality of eucerin-urea ointments prepared at different pharmacies in tehran, at the point of sale and also after two weeks storage at room temperature was exa...

'Bioconvection' is the name given to pattern-forming convective motions set up in suspensions of swimming micro-organisms. 'Gyrotaxis' describes the way the swimming is guided through a balance between the physical torques generated by viscous drag and by gravity operating on an asymmetric distribution of mass within the organism. When the organisms are heavier towards the rear, gyrotaxis turns...