The Experts below are selected from a list of 334923 Experts worldwide ranked by ideXlab platform
A F Cohen - One of the best experts on this subject based on the ideXlab platform.
-
effects of intravenous temazepam i saccadic eye movements and electroencephalogram after fast and slow infusion to pseudo steady State
Clinical Pharmacology & Therapeutics, 1994Co-Authors: Alfred L Van Steveninck, H C Schoemaker, M S M Pieters, Jan Den Hartigh, Douwe D. Breimer, Jolanda M. Rijnkels, A F CohenAbstract:Objective To study the pharmacodynamic effects of intravenous temazepam after different infusion rates to pseudo steady-State Concentrations. Methods This was a randomized, double-blind, placebo-controlled crossover study in an academic department of clinical pharmacology. Subjects were nine healthy volunteers. A computerized infusion pump was used to obtain target plasma Concentrations of temazepam after 30 or 120 minutes and to maintain these levels for 2 hours. A vehicle inftision, similar to the 30-minute (fast) infusion was used as a placebo control. Infusion schedules were based on data obtained from individual subjects after inftision of 0.4 mg/kg temazepam in 30 minutes. Target plasma Concentrations were chosen to induce subhypnotic effects and averaged (± SD) 597 ± 123 ng/ml. Venous plasma Concentrations of temazepam were measured by HPLC. Free fractions of temazepam were assessed at the start of the pseudo steady-State Concentration intervals. Electroencephalogram alpha and beta amplitudes, saccadic peak velocity, and saccadic latency were used as pharmacodynamic parameters. Results The rate of change of plasma Concentrations averaged 21 ± 4 ng/ml · min−1 during fast infusion and 5 ± 1 ng/ml · min−1 during slow infusion of temazepam. Average pseudo steady-State Concentrations were 639 ± 132 ng/ml after fast infusion and 629 ± 133 ng/ml after slow infusion. At the onset of pseudo steady-State Concentration intervals the average free fractions of temazepam were 44% (95% confidence interval, 19% to 61%) lower for slow than for fast infusions. Compared with the slow infusion, electroencephalogram beta amplitudes were significantly larger during the first 30 minutes of pseudo steady-State Concentration after fast infusion of temazepam. No significant differences were found for the other parameters. There was a slight decline of temazepam effects during the pseudo steady-State Concentration intervals for all parameters after the fast infusion and for saccadic peak velocity and saccadic latency after the slow infusion. Conclusions The pharmacodynamic effects of intravenous temazepam may depend partly on the rate of administration. Differences in pharmacodynamic effects after fast and slow infusions could be caused by changes in protein binding over time. Clinical Pharmacology and Therapeutics (1994) 55, 535–545; doi:10.1038/clpt.1994.67
-
effects of intravenous temazepam i saccadic eye movements and electroencephalogram after fast and slow infusion to pseudo steady State
Clinical Pharmacology & Therapeutics, 1994Co-Authors: Alfred L Van Steveninck, H C Schoemaker, M S M Pieters, Jan Den Hartigh, Douwe D. Breimer, Jolanda M. Rijnkels, A F CohenAbstract:Objective To study the pharmacodynamic effects of intravenous temazepam after different infusion rates to pseudo steady-State Concentrations. Methods This was a randomized, double-blind, placebo-controlled crossover study in an academic department of clinical pharmacology. Subjects were nine healthy volunteers. A computerized infusion pump was used to obtain target plasma Concentrations of temazepam after 30 or 120 minutes and to maintain these levels for 2 hours. A vehicle inftision, similar to the 30-minute (fast) infusion was used as a placebo control. Infusion schedules were based on data obtained from individual subjects after inftision of 0.4 mg/kg temazepam in 30 minutes. Target plasma Concentrations were chosen to induce subhypnotic effects and averaged (± SD) 597 ± 123 ng/ml. Venous plasma Concentrations of temazepam were measured by HPLC. Free fractions of temazepam were assessed at the start of the pseudo steady-State Concentration intervals. Electroencephalogram alpha and beta amplitudes, saccadic peak velocity, and saccadic latency were used as pharmacodynamic parameters. Results The rate of change of plasma Concentrations averaged 21 ± 4 ng/ml · min−1 during fast infusion and 5 ± 1 ng/ml · min−1 during slow infusion of temazepam. Average pseudo steady-State Concentrations were 639 ± 132 ng/ml after fast infusion and 629 ± 133 ng/ml after slow infusion. At the onset of pseudo steady-State Concentration intervals the average free fractions of temazepam were 44% (95% confidence interval, 19% to 61%) lower for slow than for fast infusions. Compared with the slow infusion, electroencephalogram beta amplitudes were significantly larger during the first 30 minutes of pseudo steady-State Concentration after fast infusion of temazepam. No significant differences were found for the other parameters. There was a slight decline of temazepam effects during the pseudo steady-State Concentration intervals for all parameters after the fast infusion and for saccadic peak velocity and saccadic latency after the slow infusion. Conclusions The pharmacodynamic effects of intravenous temazepam may depend partly on the rate of administration. Differences in pharmacodynamic effects after fast and slow infusions could be caused by changes in protein binding over time. Clinical Pharmacology and Therapeutics (1994) 55, 535–545; doi:10.1038/clpt.1994.67
Douwe D. Breimer - One of the best experts on this subject based on the ideXlab platform.
-
hepatic first pass effect and controlled drug delivery following rectal administration
Advanced Drug Delivery Reviews, 1997Co-Authors: A. G. De Boer, Douwe D. BreimerAbstract:Abstract The potentials of the rectal route, as an example of a non-invasive route for drug administration partially avoiding hepatic first-pass effect are discussed. The rectum offers a relatively constant environment for drug delivery provided the drug is presented in a well absorbable form. This allows the application of rate controlled dosage forms resulting in constant steady-State Concentration of drugs in plasma. In addition, due to the relatively constant environment, in vivo experiments indicate that the rectum offers also possibilities for rate controlled absorption enhancement. By simulations it is shown that rate controlled absorption enhancement can be achieved if adequate knowledge about the pharmacokinetics and pharmacodynamics of the enhancer is available.
-
effects of intravenous temazepam i saccadic eye movements and electroencephalogram after fast and slow infusion to pseudo steady State
Clinical Pharmacology & Therapeutics, 1994Co-Authors: Alfred L Van Steveninck, H C Schoemaker, M S M Pieters, Jan Den Hartigh, Douwe D. Breimer, Jolanda M. Rijnkels, A F CohenAbstract:Objective To study the pharmacodynamic effects of intravenous temazepam after different infusion rates to pseudo steady-State Concentrations. Methods This was a randomized, double-blind, placebo-controlled crossover study in an academic department of clinical pharmacology. Subjects were nine healthy volunteers. A computerized infusion pump was used to obtain target plasma Concentrations of temazepam after 30 or 120 minutes and to maintain these levels for 2 hours. A vehicle inftision, similar to the 30-minute (fast) infusion was used as a placebo control. Infusion schedules were based on data obtained from individual subjects after inftision of 0.4 mg/kg temazepam in 30 minutes. Target plasma Concentrations were chosen to induce subhypnotic effects and averaged (± SD) 597 ± 123 ng/ml. Venous plasma Concentrations of temazepam were measured by HPLC. Free fractions of temazepam were assessed at the start of the pseudo steady-State Concentration intervals. Electroencephalogram alpha and beta amplitudes, saccadic peak velocity, and saccadic latency were used as pharmacodynamic parameters. Results The rate of change of plasma Concentrations averaged 21 ± 4 ng/ml · min−1 during fast infusion and 5 ± 1 ng/ml · min−1 during slow infusion of temazepam. Average pseudo steady-State Concentrations were 639 ± 132 ng/ml after fast infusion and 629 ± 133 ng/ml after slow infusion. At the onset of pseudo steady-State Concentration intervals the average free fractions of temazepam were 44% (95% confidence interval, 19% to 61%) lower for slow than for fast infusions. Compared with the slow infusion, electroencephalogram beta amplitudes were significantly larger during the first 30 minutes of pseudo steady-State Concentration after fast infusion of temazepam. No significant differences were found for the other parameters. There was a slight decline of temazepam effects during the pseudo steady-State Concentration intervals for all parameters after the fast infusion and for saccadic peak velocity and saccadic latency after the slow infusion. Conclusions The pharmacodynamic effects of intravenous temazepam may depend partly on the rate of administration. Differences in pharmacodynamic effects after fast and slow infusions could be caused by changes in protein binding over time. Clinical Pharmacology and Therapeutics (1994) 55, 535–545; doi:10.1038/clpt.1994.67
-
effects of intravenous temazepam i saccadic eye movements and electroencephalogram after fast and slow infusion to pseudo steady State
Clinical Pharmacology & Therapeutics, 1994Co-Authors: Alfred L Van Steveninck, H C Schoemaker, M S M Pieters, Jan Den Hartigh, Douwe D. Breimer, Jolanda M. Rijnkels, A F CohenAbstract:Objective To study the pharmacodynamic effects of intravenous temazepam after different infusion rates to pseudo steady-State Concentrations. Methods This was a randomized, double-blind, placebo-controlled crossover study in an academic department of clinical pharmacology. Subjects were nine healthy volunteers. A computerized infusion pump was used to obtain target plasma Concentrations of temazepam after 30 or 120 minutes and to maintain these levels for 2 hours. A vehicle inftision, similar to the 30-minute (fast) infusion was used as a placebo control. Infusion schedules were based on data obtained from individual subjects after inftision of 0.4 mg/kg temazepam in 30 minutes. Target plasma Concentrations were chosen to induce subhypnotic effects and averaged (± SD) 597 ± 123 ng/ml. Venous plasma Concentrations of temazepam were measured by HPLC. Free fractions of temazepam were assessed at the start of the pseudo steady-State Concentration intervals. Electroencephalogram alpha and beta amplitudes, saccadic peak velocity, and saccadic latency were used as pharmacodynamic parameters. Results The rate of change of plasma Concentrations averaged 21 ± 4 ng/ml · min−1 during fast infusion and 5 ± 1 ng/ml · min−1 during slow infusion of temazepam. Average pseudo steady-State Concentrations were 639 ± 132 ng/ml after fast infusion and 629 ± 133 ng/ml after slow infusion. At the onset of pseudo steady-State Concentration intervals the average free fractions of temazepam were 44% (95% confidence interval, 19% to 61%) lower for slow than for fast infusions. Compared with the slow infusion, electroencephalogram beta amplitudes were significantly larger during the first 30 minutes of pseudo steady-State Concentration after fast infusion of temazepam. No significant differences were found for the other parameters. There was a slight decline of temazepam effects during the pseudo steady-State Concentration intervals for all parameters after the fast infusion and for saccadic peak velocity and saccadic latency after the slow infusion. Conclusions The pharmacodynamic effects of intravenous temazepam may depend partly on the rate of administration. Differences in pharmacodynamic effects after fast and slow infusions could be caused by changes in protein binding over time. Clinical Pharmacology and Therapeutics (1994) 55, 535–545; doi:10.1038/clpt.1994.67
Alfred L Van Steveninck - One of the best experts on this subject based on the ideXlab platform.
-
effects of intravenous temazepam i saccadic eye movements and electroencephalogram after fast and slow infusion to pseudo steady State
Clinical Pharmacology & Therapeutics, 1994Co-Authors: Alfred L Van Steveninck, H C Schoemaker, M S M Pieters, Jan Den Hartigh, Douwe D. Breimer, Jolanda M. Rijnkels, A F CohenAbstract:Objective To study the pharmacodynamic effects of intravenous temazepam after different infusion rates to pseudo steady-State Concentrations. Methods This was a randomized, double-blind, placebo-controlled crossover study in an academic department of clinical pharmacology. Subjects were nine healthy volunteers. A computerized infusion pump was used to obtain target plasma Concentrations of temazepam after 30 or 120 minutes and to maintain these levels for 2 hours. A vehicle inftision, similar to the 30-minute (fast) infusion was used as a placebo control. Infusion schedules were based on data obtained from individual subjects after inftision of 0.4 mg/kg temazepam in 30 minutes. Target plasma Concentrations were chosen to induce subhypnotic effects and averaged (± SD) 597 ± 123 ng/ml. Venous plasma Concentrations of temazepam were measured by HPLC. Free fractions of temazepam were assessed at the start of the pseudo steady-State Concentration intervals. Electroencephalogram alpha and beta amplitudes, saccadic peak velocity, and saccadic latency were used as pharmacodynamic parameters. Results The rate of change of plasma Concentrations averaged 21 ± 4 ng/ml · min−1 during fast infusion and 5 ± 1 ng/ml · min−1 during slow infusion of temazepam. Average pseudo steady-State Concentrations were 639 ± 132 ng/ml after fast infusion and 629 ± 133 ng/ml after slow infusion. At the onset of pseudo steady-State Concentration intervals the average free fractions of temazepam were 44% (95% confidence interval, 19% to 61%) lower for slow than for fast infusions. Compared with the slow infusion, electroencephalogram beta amplitudes were significantly larger during the first 30 minutes of pseudo steady-State Concentration after fast infusion of temazepam. No significant differences were found for the other parameters. There was a slight decline of temazepam effects during the pseudo steady-State Concentration intervals for all parameters after the fast infusion and for saccadic peak velocity and saccadic latency after the slow infusion. Conclusions The pharmacodynamic effects of intravenous temazepam may depend partly on the rate of administration. Differences in pharmacodynamic effects after fast and slow infusions could be caused by changes in protein binding over time. Clinical Pharmacology and Therapeutics (1994) 55, 535–545; doi:10.1038/clpt.1994.67
-
effects of intravenous temazepam i saccadic eye movements and electroencephalogram after fast and slow infusion to pseudo steady State
Clinical Pharmacology & Therapeutics, 1994Co-Authors: Alfred L Van Steveninck, H C Schoemaker, M S M Pieters, Jan Den Hartigh, Douwe D. Breimer, Jolanda M. Rijnkels, A F CohenAbstract:Objective To study the pharmacodynamic effects of intravenous temazepam after different infusion rates to pseudo steady-State Concentrations. Methods This was a randomized, double-blind, placebo-controlled crossover study in an academic department of clinical pharmacology. Subjects were nine healthy volunteers. A computerized infusion pump was used to obtain target plasma Concentrations of temazepam after 30 or 120 minutes and to maintain these levels for 2 hours. A vehicle inftision, similar to the 30-minute (fast) infusion was used as a placebo control. Infusion schedules were based on data obtained from individual subjects after inftision of 0.4 mg/kg temazepam in 30 minutes. Target plasma Concentrations were chosen to induce subhypnotic effects and averaged (± SD) 597 ± 123 ng/ml. Venous plasma Concentrations of temazepam were measured by HPLC. Free fractions of temazepam were assessed at the start of the pseudo steady-State Concentration intervals. Electroencephalogram alpha and beta amplitudes, saccadic peak velocity, and saccadic latency were used as pharmacodynamic parameters. Results The rate of change of plasma Concentrations averaged 21 ± 4 ng/ml · min−1 during fast infusion and 5 ± 1 ng/ml · min−1 during slow infusion of temazepam. Average pseudo steady-State Concentrations were 639 ± 132 ng/ml after fast infusion and 629 ± 133 ng/ml after slow infusion. At the onset of pseudo steady-State Concentration intervals the average free fractions of temazepam were 44% (95% confidence interval, 19% to 61%) lower for slow than for fast infusions. Compared with the slow infusion, electroencephalogram beta amplitudes were significantly larger during the first 30 minutes of pseudo steady-State Concentration after fast infusion of temazepam. No significant differences were found for the other parameters. There was a slight decline of temazepam effects during the pseudo steady-State Concentration intervals for all parameters after the fast infusion and for saccadic peak velocity and saccadic latency after the slow infusion. Conclusions The pharmacodynamic effects of intravenous temazepam may depend partly on the rate of administration. Differences in pharmacodynamic effects after fast and slow infusions could be caused by changes in protein binding over time. Clinical Pharmacology and Therapeutics (1994) 55, 535–545; doi:10.1038/clpt.1994.67
Zhongliang Tian - One of the best experts on this subject based on the ideXlab platform.
-
effect of ni content on corrosion behavior of ni 10nio 90nife2o4 cermet inert anode
Transactions of Nonferrous Metals Society of China, 2008Co-Authors: Zhongliang TianAbstract:Abstract Ni/(10NiO-90NiFe 2 O 4 ) cermet inert anodes with metal Ni content of 0, 5, 10, 15 and 20 (mass fraction, %) were prepared and their corrosion behavior in Na 3 AlF 6 -Al 2 O 3 melts was investigated in laboratory electrolysis tests. The results indicate that the content of metal Ni in anodes has little effect on the steady-State Concentration of impurities Ni and Fe in electrolyte and the values range in (114–173)×10 −6 and (287–385)×10 −6 , but the content of impurities in the metal aluminum manifolds. There is preferential corrosion for metal Ni in NiO-NiFe 2 O 4 based cermet anodes. Considering the corrosion resistance and electrical conductivity, the cermet containing 5%Ni (mass fraction) behaves best among NiO-NiFe 2 O 4 based cermet anodes studied, and should be further studied.
-
effect of cu ni content on the corrosion resistance of cu ni 10nio 90nife2o4 cermet inert anode for aluminum electrolysis
Acta Metallurgica Sinica (english Letters), 2008Co-Authors: Zhongliang TianAbstract:(Cu-Ni)/(10NiO-90NiFe2O4) cermet inert anodes containing metal Cu-Ni 0, 5, 10, 15 and 20 wt pct were prepared and their corrosion resistance to Na3AlF6-Al2O3 melts was investigated. The results indicate that the content of metal Cu-Ni has little effect on the steady-State Concentration of Ni in the electrolyte and the values could not be used to effectively differentiate their corrosion resistance. The steady-State Concentration of Fe decreases from 304×10−6 to 168×10−6 and that of Cu increases from 21×10−6 to 71×10−6 with the content of metal Cu-Ni increasing from 0 to 20 wt pct. Post-examination shows that metallic phase Cu-Ni is corroded preferentially during electrolysis and many pores are left at the anode surface. Considering the corrosion resistance and electrical conductivity, the cermet containing metal Cu-Ni 5 wt pct should be selected and studied further.
-
effect of metallic phase species on the corrosion resistance of 17m 10nio nife 2 o 4 cermet inert anode of aluminum electrolysis
Journal of Central South University of Technology, 2006Co-Authors: Xinzheng Li, Zhongliang Tian, Jie Li, Gang ZhangAbstract:NiFe2O4-based cermet inert anodes with metallic phase compositions of Cu, Ni and 85Cu15Ni were prepared by cold pressing-sintering. Their corrosion resistance was also investigated in Na3AlF6-Al2O3 melts. The results show that the metallic phase species in cermets have no effect on the Concentration of impurities in bath during electrolysis, the total steady-State Concentration of impurities is almost the same, i. e. between 4.12×10−4−4.80×10−4. There exists metal preferential corrosion for the cermet inert anode with metal Ni as metallic phase. For NiFe2O4-based cermets, the cermet with metal Cu as metallic phase exhibits better corrosion resistance than the others.
H C Schoemaker - One of the best experts on this subject based on the ideXlab platform.
-
effects of intravenous temazepam i saccadic eye movements and electroencephalogram after fast and slow infusion to pseudo steady State
Clinical Pharmacology & Therapeutics, 1994Co-Authors: Alfred L Van Steveninck, H C Schoemaker, M S M Pieters, Jan Den Hartigh, Douwe D. Breimer, Jolanda M. Rijnkels, A F CohenAbstract:Objective To study the pharmacodynamic effects of intravenous temazepam after different infusion rates to pseudo steady-State Concentrations. Methods This was a randomized, double-blind, placebo-controlled crossover study in an academic department of clinical pharmacology. Subjects were nine healthy volunteers. A computerized infusion pump was used to obtain target plasma Concentrations of temazepam after 30 or 120 minutes and to maintain these levels for 2 hours. A vehicle inftision, similar to the 30-minute (fast) infusion was used as a placebo control. Infusion schedules were based on data obtained from individual subjects after inftision of 0.4 mg/kg temazepam in 30 minutes. Target plasma Concentrations were chosen to induce subhypnotic effects and averaged (± SD) 597 ± 123 ng/ml. Venous plasma Concentrations of temazepam were measured by HPLC. Free fractions of temazepam were assessed at the start of the pseudo steady-State Concentration intervals. Electroencephalogram alpha and beta amplitudes, saccadic peak velocity, and saccadic latency were used as pharmacodynamic parameters. Results The rate of change of plasma Concentrations averaged 21 ± 4 ng/ml · min−1 during fast infusion and 5 ± 1 ng/ml · min−1 during slow infusion of temazepam. Average pseudo steady-State Concentrations were 639 ± 132 ng/ml after fast infusion and 629 ± 133 ng/ml after slow infusion. At the onset of pseudo steady-State Concentration intervals the average free fractions of temazepam were 44% (95% confidence interval, 19% to 61%) lower for slow than for fast infusions. Compared with the slow infusion, electroencephalogram beta amplitudes were significantly larger during the first 30 minutes of pseudo steady-State Concentration after fast infusion of temazepam. No significant differences were found for the other parameters. There was a slight decline of temazepam effects during the pseudo steady-State Concentration intervals for all parameters after the fast infusion and for saccadic peak velocity and saccadic latency after the slow infusion. Conclusions The pharmacodynamic effects of intravenous temazepam may depend partly on the rate of administration. Differences in pharmacodynamic effects after fast and slow infusions could be caused by changes in protein binding over time. Clinical Pharmacology and Therapeutics (1994) 55, 535–545; doi:10.1038/clpt.1994.67
-
effects of intravenous temazepam i saccadic eye movements and electroencephalogram after fast and slow infusion to pseudo steady State
Clinical Pharmacology & Therapeutics, 1994Co-Authors: Alfred L Van Steveninck, H C Schoemaker, M S M Pieters, Jan Den Hartigh, Douwe D. Breimer, Jolanda M. Rijnkels, A F CohenAbstract:Objective To study the pharmacodynamic effects of intravenous temazepam after different infusion rates to pseudo steady-State Concentrations. Methods This was a randomized, double-blind, placebo-controlled crossover study in an academic department of clinical pharmacology. Subjects were nine healthy volunteers. A computerized infusion pump was used to obtain target plasma Concentrations of temazepam after 30 or 120 minutes and to maintain these levels for 2 hours. A vehicle inftision, similar to the 30-minute (fast) infusion was used as a placebo control. Infusion schedules were based on data obtained from individual subjects after inftision of 0.4 mg/kg temazepam in 30 minutes. Target plasma Concentrations were chosen to induce subhypnotic effects and averaged (± SD) 597 ± 123 ng/ml. Venous plasma Concentrations of temazepam were measured by HPLC. Free fractions of temazepam were assessed at the start of the pseudo steady-State Concentration intervals. Electroencephalogram alpha and beta amplitudes, saccadic peak velocity, and saccadic latency were used as pharmacodynamic parameters. Results The rate of change of plasma Concentrations averaged 21 ± 4 ng/ml · min−1 during fast infusion and 5 ± 1 ng/ml · min−1 during slow infusion of temazepam. Average pseudo steady-State Concentrations were 639 ± 132 ng/ml after fast infusion and 629 ± 133 ng/ml after slow infusion. At the onset of pseudo steady-State Concentration intervals the average free fractions of temazepam were 44% (95% confidence interval, 19% to 61%) lower for slow than for fast infusions. Compared with the slow infusion, electroencephalogram beta amplitudes were significantly larger during the first 30 minutes of pseudo steady-State Concentration after fast infusion of temazepam. No significant differences were found for the other parameters. There was a slight decline of temazepam effects during the pseudo steady-State Concentration intervals for all parameters after the fast infusion and for saccadic peak velocity and saccadic latency after the slow infusion. Conclusions The pharmacodynamic effects of intravenous temazepam may depend partly on the rate of administration. Differences in pharmacodynamic effects after fast and slow infusions could be caused by changes in protein binding over time. Clinical Pharmacology and Therapeutics (1994) 55, 535–545; doi:10.1038/clpt.1994.67
