RESUMO
p-Nitroaniline ( PNA) was one kind of highly toxic aromatic amine and becomes an environmental pollutant in recent years. Here we reported the construction of a fluorescent sensor based on an anionic pyrene, 8-hydroxypyrene-1,3,6-trisulfonic acid trisodium salt (HPTS), for the rapid and visual detection of PNA in aqueous media. The fluorescence quenching of HPTS caused by the presence of PNA was through non-covalent interactions. A good linear relationship between fluorescent intensity of HPTS at 512 nm was obtained in the range of 10-120 μmol/L. The detection limit (3σ) of this approach was 4. 6 μmol/L. The results showed that the method was suitable for rapid detection of PNA in real samples with good sensitivity, selectivity, anti-interference, low cost and easy operation.
RESUMO
p-Nitroaniline ( PNA) was one kind of highly toxic aromatic amine and becomes an environmental pollutant in recent years. Here we reported the construction of a fluorescent sensor based on an anionic pyrene, 8-hydroxypyrene-1,3,6-trisulfonic acid trisodium salt (HPTS), for the rapid and visual detection of PNA in aqueous media. The fluorescence quenching of HPTS caused by the presence of PNA was through non-covalent interactions. A good linear relationship between fluorescent intensity of HPTS at 512 nm was obtained in the range of 10-120 μmol/L. The detection limit (3σ) of this approach was 4. 6 μmol/L. The results showed that the method was suitable for rapid detection of PNA in real samples with good sensitivity, selectivity, anti-interference, low cost and easy operation.
RESUMO
Objective To evaluate the effects of different doses of lidocaine on suppressing fentanyl-induced cough and determine a safe suppressing dose.Methods Two hundred patients undergoing general anesthesia were randomized to four groups evenly.The following medications were given within ten seconds:normal saline 10ml (groupⅠ,control group),lidocaine 1 mg/kg (groupⅡ),lidoeaine 1.5 mg/kg(groupⅢ),lidocaine 2mg/kg (groupⅣ).Toxic symptoms of lidocaine were recorded within lmin after the administration of lidocaine,then fentanyl 3?g/ kg was given intravenously within 5 seconds.Cough incidence and cough grade were recorded within 2rain after the administration of fentanyl.Systolic blood pressure (SBP),diastolic blood pressure (DBP),heart rates (HR),and satu- ration of pulse oximeter(SpO2) were recorded during different time points of induction,all recorded data were anal- ysed by the statistical software,P value