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J Fraissard - One of the best experts on this subject based on the ideXlab platform.
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Application of the Xenon-129 NMR technique. 1. Variable-temperature Xenon-129 NMR study of Xenon adsorbed in zeolites
The Journal of Physical Chemistry, 1992Co-Authors: Q. J. Chen, J FraissardAbstract:Variable-temperature 129 Xe NMR has been used to study the adsorption state of Xenon inside zeolites. It is shown that the way Xenon behaves inside a zeolite depends much upon the experimental temperature as well as on the amount of Xenon adsorbed. At room temperature, adsorbed Xenon can move quite freely in all the space where it is adsorbed, which proves the validity of the fast exchange model
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Application of the Xenon-129 NMR technique. 2. Xenon-129 NMR study of Xenon diffusion between zeolite crystallites
The Journal of Physical Chemistry, 1992Co-Authors: Q. J. Chen, J FraissardAbstract:129 Xe NMR has been used to study the diffusion of adsorbed Xenon between zeolite crystallites. This intercrystallite Xenon diffusion depends much upon zeolite structure. Other factors such as zeolite dilution, compression and experiment temperature can also greatly influence the Xenon NMR results. Details of these effects are dicussed in the present work. This information is of vital importance from the point of view of the application of the Xenon NMR technique to the study of industrial zeolitic catalysts
Q. J. Chen - One of the best experts on this subject based on the ideXlab platform.
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Application of the Xenon-129 NMR technique. 1. Variable-temperature Xenon-129 NMR study of Xenon adsorbed in zeolites
The Journal of Physical Chemistry, 1992Co-Authors: Q. J. Chen, J FraissardAbstract:Variable-temperature 129 Xe NMR has been used to study the adsorption state of Xenon inside zeolites. It is shown that the way Xenon behaves inside a zeolite depends much upon the experimental temperature as well as on the amount of Xenon adsorbed. At room temperature, adsorbed Xenon can move quite freely in all the space where it is adsorbed, which proves the validity of the fast exchange model
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Application of the Xenon-129 NMR technique. 2. Xenon-129 NMR study of Xenon diffusion between zeolite crystallites
The Journal of Physical Chemistry, 1992Co-Authors: Q. J. Chen, J FraissardAbstract:129 Xe NMR has been used to study the diffusion of adsorbed Xenon between zeolite crystallites. This intercrystallite Xenon diffusion depends much upon zeolite structure. Other factors such as zeolite dilution, compression and experiment temperature can also greatly influence the Xenon NMR results. Details of these effects are dicussed in the present work. This information is of vital importance from the point of view of the application of the Xenon NMR technique to the study of industrial zeolitic catalysts
Rolf Rossaint - One of the best experts on this subject based on the ideXlab platform.
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evaluation of bispectral index and auditory evoked potentials for hypnotic depth monitoring during balanced Xenon anaesthesia compared with sevoflurane
BJA: British Journal of Anaesthesia, 2010Co-Authors: Astrid V Fahlenkamp, Rolf Rossaint, D Peters, Ingeborg Biener, C Billoet, Christian C Apfel, Mark CoburnAbstract:Abstract Background None of the currently available hypnosis monitoring systems have evaluated balanced Xenon anaesthesia. We investigated the performance of the bispectral index (BIS) and the composite A-line autoregressive index (cAAI) while comparing balanced Xenon with sevoflurane anaesthesia. Methods Sixty patients undergoing elective abdominal surgery participated in this registered double-blinded, controlled trial and—after written informed consent—were randomly assigned to one of the study groups (Xenon, n=30; sevoflurane, n=30). After induction, general anaesthesia was maintained with Xenon 60% or sevoflurane 2.0% in 30% O2. Remifentanil was titrated to clinical needs. BIS and cAAI values were recorded electronically and blinded to the performing physician. Emergence from anaesthesia was evaluated and during 12 h follow-up, patients were questioned twice for signs of recalls. Results During induction and maintenance of anaesthesia, BIS values in the Xenon group were comparable with sevoflurane anaesthesia and within the recommended range. Although the cAAI remained stable in the sevoflurane group, values increased during balanced Xenon anaesthesia and exceeded the recommended upper limit after 65 min. Emergence from Xenon anaesthesia was significantly faster than from sevoflurane (eye opening at 3.8 vs 10.3 min, P Conclusions During surgery, Xenon/remifentanil anaesthesia can be monitored using BIS and cAAI. However, cAAI values changed after about 1 h of anaesthesia. Further studies will be needed to address the question whether auditory signal processing is altered during extended Xenon exposure.
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the effect of Xenon anesthesia on the size of experimental myocardial infarction
Anesthesia & Analgesia, 2007Co-Authors: Janh Baumert, Marc Hein, Christina Gerets, Thomas Baltus, K Hecker, Rolf RossaintAbstract:BACKGROUND: Volatile anesthetics protect the myocardium from ischemia reperfusion damage. Our hypothesis for this study was that Xenon reduces the size of myocardial infarction similar in extent to the reduction associated with ischemic preconditioning. METHODS: Thirty-six pigs weighing 30-35 kg were anesthetized with thiopental and then randomized into four groups: control (myocardial ischemia only), ischemic preconditioning (five 5-min episodes of intermittent myocardial ischemia), Xenon preconditioning (three 10-min exposures to Xenon 70% followed by myocardial ischemia), and Xenon anesthesia (Xenon 70%, continued before and after myocardial ischemia). Myocardial ischemia was induced by placing a tourniquet around the left anterior descending coronary artery for 60 min followed by 2 h of reperfusion. Myocardial infarct size and the area at risk for myocardial infarction were measured by Evans Blue and triphenyl tetrazolium chloride staining, respectively. RESULTS: Mean (sd) myocardial infarct size was reduced from 64% +/- 9% of the area at risk in the control group to 19% +/- 12% with ischemic preconditioning (P < 0.001), and to 50% +/- 9% with Xenon anesthesia (P < 0.05 versus control, P < 0.001 versus ischemic preconditioning). Myocardial infarct size was not reduced with Xenon preconditioning compared with the control group (59% +/- 11%, P = 0.41). CONCLUSION: Myocardial infarct size was reduced by ischemic preconditioning but less so by Xenon anesthesia. Brief, intermittent exposure to Xenon before myocardial ischemia did not reduce myocardial infarct size.
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Xenon, a modern anaesthesia gas.
Minerva anestesiologica, 2004Co-Authors: K Hecker, J.-h. Baumert, N Horn, Rolf RossaintAbstract:Xenon is an interesting anesthetic as it appears to lack negative inotropicy and vasodilatation, giving great advantages to both patients with limited cardiovascular reserve or those who require hemodynamic stability. It has low toxicity and is not teratogenic. Xenon gives rapid induction and recovery, due to its low blood/gas partition coefficient (0.15), and has a MAC of 63%. Several vitro studies showed that Xenon may protect neural cells against ischaemic injury. Its low blood solubility can take to diffusion hypoxia if Xenon is not substituted by 100% oxygen at the end of anesthesia. It has been shown that, compared to other anesthetic regimens, Xenon anesthesia produces the highest regional blood flow in the brain, liver, kidney and intestine. In conclusion, the most important positive effects of Xenon are cardiovascular stability, cerebral protection and favourable pharmacokinetics. Negative points are high cost and the limited number of ventilators supplying Xenon.
Luís F. G. Martins - One of the best experts on this subject based on the ideXlab platform.
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On the behaviour of solutions of Xenon in liquid cycloalkanes: Solubility of Xenon in cyclopentane
Fluid Phase Equilibria, 2011Co-Authors: Rui P. Bonifácio, Eduardo J. M. Filipe, M. Carolina Dos Ramos, Francisco Javier Garcia Blas, Luís F. G. MartinsAbstract:Abstract The solubility of Xenon in liquid cyclopentane has been studied experimentally and theoretically. Measurements of the solubility of Xenon in liquid cyclopentane are reported as a function of temperature from 254.60 K to 313.66 K. The imprecision of the experimental data is less than 0.3%. The thermodynamic functions of solvation of Xenon in cyclopentane, such as the standard Gibbs energy, enthalpy, entropy and heat capacity of solvation, have been calculated from the temperature dependence of Henry's law coefficients. The results provide further information about the differences between the Xenon + cycloalkanes and the Xenon + n-alkane interactions. In particular, interaction enthalpies between Xenon and CH2 groups in n-alkanes and cycloalkanes have been estimated and compared. Using a version of the soft-SAFT approach developed to model cyclic molecules, we were able to reproduce the experimental solubility for Xenon in cyclopentane using simple Lorentz-Berthelot rules to describe the unlike interaction.
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On the Behavior of Solutions of Xenon in Liquid n-Alkanes: Solubility of Xenon in n-Pentane and n-Hexane
The journal of physical chemistry. B, 2010Co-Authors: Rui P. Bonifácio, Luís F. G. Martins, Clare Mccabe, Eduardo J. M. FilipeAbstract:The solubility of Xenon in liquid n-pentane and n-hexane has been studied experimentally, theoretically, and by computer simulation. Measurements of the solubility are reported for Xenon + n-pentane as a function of temperature from 254 to 305 K. The uncertainty in the experimental data is less than 0.15%. The thermodynamic functions of solvation such as the standard Gibbs energy, enthalpy, and entropy of solvation have been calculated from Henry’s law coefficients for Xenon + n-pentane solutions and also for Xenon + n-hexane, which were reported in previous work. The results provide a further example of the similarity between the Xenon + n-alkane interaction and the n-alkane + n-alkane interactions. Using the SAFT-VR approach we were able to quantitatively predict the experimental solubility for Xenon in n-pentane and semiquantitatively that of Xenon in n-hexane using simple Lorentz−Berthelot combining rules to describe the unlikely interaction. Henry’s constants at infinite dilution for Xenon + n-pentan...
Eduardo J. M. Filipe - One of the best experts on this subject based on the ideXlab platform.
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On the behaviour of solutions of Xenon in liquid cycloalkanes: Solubility of Xenon in cyclopentane
Fluid Phase Equilibria, 2011Co-Authors: Rui P. Bonifácio, Eduardo J. M. Filipe, M. Carolina Dos Ramos, Francisco Javier Garcia Blas, Luís F. G. MartinsAbstract:Abstract The solubility of Xenon in liquid cyclopentane has been studied experimentally and theoretically. Measurements of the solubility of Xenon in liquid cyclopentane are reported as a function of temperature from 254.60 K to 313.66 K. The imprecision of the experimental data is less than 0.3%. The thermodynamic functions of solvation of Xenon in cyclopentane, such as the standard Gibbs energy, enthalpy, entropy and heat capacity of solvation, have been calculated from the temperature dependence of Henry's law coefficients. The results provide further information about the differences between the Xenon + cycloalkanes and the Xenon + n-alkane interactions. In particular, interaction enthalpies between Xenon and CH2 groups in n-alkanes and cycloalkanes have been estimated and compared. Using a version of the soft-SAFT approach developed to model cyclic molecules, we were able to reproduce the experimental solubility for Xenon in cyclopentane using simple Lorentz-Berthelot rules to describe the unlike interaction.
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On the Behavior of Solutions of Xenon in Liquid n-Alkanes: Solubility of Xenon in n-Pentane and n-Hexane
The journal of physical chemistry. B, 2010Co-Authors: Rui P. Bonifácio, Luís F. G. Martins, Clare Mccabe, Eduardo J. M. FilipeAbstract:The solubility of Xenon in liquid n-pentane and n-hexane has been studied experimentally, theoretically, and by computer simulation. Measurements of the solubility are reported for Xenon + n-pentane as a function of temperature from 254 to 305 K. The uncertainty in the experimental data is less than 0.15%. The thermodynamic functions of solvation such as the standard Gibbs energy, enthalpy, and entropy of solvation have been calculated from Henry’s law coefficients for Xenon + n-pentane solutions and also for Xenon + n-hexane, which were reported in previous work. The results provide a further example of the similarity between the Xenon + n-alkane interaction and the n-alkane + n-alkane interactions. Using the SAFT-VR approach we were able to quantitatively predict the experimental solubility for Xenon in n-pentane and semiquantitatively that of Xenon in n-hexane using simple Lorentz−Berthelot combining rules to describe the unlikely interaction. Henry’s constants at infinite dilution for Xenon + n-pentan...
