the acute ecotoxicity of a set of mixture samples (washing powders, wastes, fuel extracts etc.) was assessed using four acute ecotoxicity assays with aquatic organisms (daphnia magna, poecilia reticulata, artemia salina and desmodesmus subspicatus). the experimental concentration-response curves were fitted by seven two-parameter sigmoid equations using non-linear regression. the regression pe...

the acute ecotoxicity of a set of mixture samples (washing powders, wastes, fuel extracts etc.) was assessed using four acute ecotoxicity assays with aquatic organisms (daphnia magna, poecilia reticulata, artemia salina and desmodesmus subspicatus). the experimental concentration-response curves were fitted by seven two-parameter sigmoid equations using non-linear regression. the regression per...

ignoring two main characteristics of the concentration-response data, correlation between observations and presence of outliers, may lead to misleading results. therefore the special method should be considered. in this paper in to examine the effect of phenylephrine in rat corpus cavernosum, outlier robust nonlinear mixed estimation is used. in this study, eight different doses of phenylephrin...

Concentration-response curves (CRCs) are characterized by a midpoint (EC50) and high-concentration asymptote (POmax) that relate to the agonist's affinity efficacy. Recently, third agonist attribute, efficiency, was defined as fraction of ligand binding energy is applied conformational change activates receptor. We show efficiency can be calculated from EC50 POmax estimate its value for 17 agon...

the stimulatory effect of the extract of portulaca oleracea (p. olerace) on β-adrenoceptor of tracheal smooth muscle was examined. to examine β-adrenoceptor stimulatory effect, concentration response curve to isoprenaline was obtained in pre-contracted tracheal smooth muscle in the presence of three concentrations of aqueous-ethanolic extract, propranolol and saline. values of ec50 (the effecti...

ketotifen is a benzocycloheptathiophene with a range of pharmacological activities. the present study was carried out to evaluate the action of ketotifen on isolated rat bladder contractions induced by kci and acetylcholine, compared with the effects of other drugs. ketotifen (5 µm) reduced the response to acetylcholine on rat isolated bladder without altering the maximum response and shifted t...

equitable distribution of health system resources has been a serious challenge for long ago among the health policy makers. conducted studies have mostly ever had emphasis on equality rather than equity. in this paper we have attempted to examine both equality and equity in resources distribution.this is an applied and descriptive study in which we plotted lorenz and concentration curves to des...