Photoluminescence spectra of porous silicon modified by copper phthalocyanine coating
In this paper we present photoluminescence (PL) spectra of porous silicon (PSi) coated with thin top layer of copper phthalocyanine (CuPc). PSi was by electrochemical anodisation method prepared. CuPc based thin organic film was using physical vapor deposition (PVD) in high vacuum on the top of fresh PSi deposited. PL was under pulsed excitation measured and samples were in vacuum enclosed. PSi/CuPc samples exhibit strong photoluminescence in visible region at room temperature. Observed PL spectra exhibit multiband structure and such structure changes in red region compared to “clean” PSi. Properties of PSi/organic luminescence can be explained by penetration of organic material into PSi skeleton and interaction between carriers in PSi and deposited material.
Real-time multichannel scaler measurement of oscillator instabilities
This article describes measurement of oscillator instabilities by a method using the real-time multichannel scaler (RTMS). A theoretical model for such application is also considered. The general problem of the oscillator instability measurements in time domain is discussed. The results of oscillator instability measurements using the real-time multichannel scaler and a time interval analyzer are compared. The full range of application of this method is up to 7E-7 and depends strongly on the RTMS construction. We present the results of oscillator instability measurements of the order of 3E-5, using the RTMS with a resolution of 3.13 ns and the range of operation 3.28 ms.
Pharmacokinetics of Mivacurium Isomers and Their Metabolites in Healthy Volunteers after Intravenous Bolus Administration
Background Previous studies report the pharmacokinetics of mivacurium isomers after an infusion using venous blood sampling. Although the extent of the mivacurium arterial‐venous gradient is not known, the sampling site is likely to influence mivacurium pharmacokinetic parameters because the drug is rapidly metabolized as it traverses the circulation. The objectives of this study were (1) to determine the pharmacokinetics of mivacurium isomers in healthy persons after intravenous bolus administration using intensive arterial blood sampling, and (2) to characterize the formation and elimination of mivacurium metabolites in human plasma. Methods Eight persons classified as American Society of Anesthesiologists physical status 1 or 2 who were scheduled to undergo elective surgery under balanced anesthesia received 0.15 mg/kg mivacurium chloride as an intravenous bolus. Arterial blood samples were collected every 10 s during the first 2 min and at frequent intervals for 4 h thereafter. Plasma concentrations of mivacurium isomers and their metabolites were determined by two stereoselective high‐performance liquid chromatographic methods coupled with fluorometric detection and noncompartmental pharmacokinetic parameters. Results Mean elimination half‐lives of the trans‐trans, cis‐trans, and cis‐cis isomers were 2.4, 2, and 28.5 min, respectively, with corresponding mean plasma clearances of 29.2, 45.7, and 6.7 ml [center dot] min‐1 [center dot] kg‐1. The volumes of distribution at steady state of the trans‐trans, cis‐trans, and cis‐cis isomers were 0.047, 0.054, and 0.189 l/kg, respectively. Plasma concentrations of monoester and alcohol metabolites peaked 25 s (median) after mivacurium injection, with half‐lives in the range of 90 min, except for the cis alcohol metabolite, which was only negligibly and transiently formed. Conclusions Substantial hydrolysis of mivacurium isomers by cholinesterases was confirmed by the rapid appearance of mivacurium metabolites in plasma. The intensive arterial sampling proved to be critical for the trans‐trans and cis‐trans isomers because the area under the curve between 0 and 2 min accounted for 75% and 86% of the total, respectively.