Our study is motivated by the increasing interest in accurate measurements
and mechanistic understanding of the thermal transport properties of zeolite materials. The presence of a nanostructured pore network, extra-framework cations, and tunable framework structure and composition confer interesting thermophysical properties to these materials, making them a good model PF-04554878 system to investigate thermal transport in complex materials. Continuous films of zeolite LTA with different nonframework cations (Na(+), K(+), and Ca(+2)) were synthesized and characterized. The thermal conductivity was measured using the three-omega method over a wide range of temperature (150-450 K). These are the first thermal conductivity measurements performed on bulk LTA, so they are more accurate than previous measurements, which involved the use of compacted zeolite powders. Our data showed significant dependence of the thermal conductivity on the extra-framework cations as well the temperature. The thermal conductivities of the zeolite LTA samples were modeled with the relaxation time
approximation to the Boltzmann transport Integrase inhibitor equation. The full phonon spectra for each type of LTA zeolite were calculated and used in conjunction with semiempirical relaxation time expressions to calculate the thermal conductivity. The results both validated, and suggested the limitations of, this modeling approach. Optical phonons dominated the thermal conductivity and boundarylike scattering was found to be the strongest phonon scattering mechanism, as also observed in MFI zeolite.”
“Background: Transfer to hemodialysis (HD) is a frequent cause of peritoneal dialysis (PD) cessation. In the present study, we set out to describe the transition period between PD and HD.
Methods: All patients in 4 centers of Basse-Normandie who had been treated with PD for more than 90 days and who were permanently transferred to HD between 1 January 2005 and 31 December 2009 were retrospectively reviewed. The rate of Selleckchem Ro-3306 unplanned HD start was evaluated.
Results: In the 60 patients (39 men, 21 women) included in the study, median score on the Charlson
comorbidity index at PD initiation was 5 [interquartile range (IQR): 3 - 7], median age at HD initiation was 62 years (IQR: 54 – 76 years), and median duration on PD was 22 months (IQR: 12 – 36 months). Among the 60 patients, 37 had an unplanned HD initiation. Peritonitis was the most frequent cause of unplanned HD start (n = 20), and dialysis inadequacy (n = 11), the main cause of planned HD start. During the transition period, all patients were hospitalized. Median duration of hospitalization was 4.5 days (IQR: 0 – 25.5 days). Within 2 months after HD initiation, 9 patients died. Two months after starting HD, 6 of the remaining 51 patients were being treated in a self-care HD unit and only 23 patients had a mature fistula.