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...

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...

Polyakov et al. (1995) showed errors in dose estimation as a function of grain size for enamel grains given beta irradiation after crushing. We tested the effect of gamma irradiation applied to the specimens before and after crushing. We confirmed Polyakov's observations and found that post-crushing irradiation altered the slope of the dose-response curve of the hydroxyapatite signal and produc...

The dose/response curve in enzyme-multiplied immunoassays (EMIT) and related techniques may be described by the same "four-parameter logistic function" as has proven useful in radioimmunoassays, immunoradiometric assays (IRMA), and two-site immunoradiometric ("sandwhich") assays. This function provides an empirical description of the dose/response curve by use of an objective least-squares regr...

Quantitative microbial risk assessment has been used to develop criteria for exposure many microorganisms. In this article, the dose–response curve Coronavirus 229E is preliminary risk-based SARS-CoV-2 via respiratory portals of entry.

The effects of cyclic ADP-ribose (cADPR) and the immunosuppressant drug FK506 on microsomal Ca2+ release through a ryanodine-sensitive mechanism were investigated in rat pancreatic acinar cells. After a steady state of 45Ca2+ uptake into the microsomal vesicles, ryanodine or caffeine was added. Preincubation of the vesicles with cADPR (0.5 microM) shifted the dose-response curve of ryanodine- o...

Dose-response relationships for aquatic organisms have been developed for numerous contaminants using external media exposures (water and sediment). Dose-response relationships based on internal concentrations (tissue residues) are limited. The present study reports Hg dose-response curves for early life stage and juvenile or adult fish based on published tissue-residue toxicity studies. These ...