ECMO for COVID-19 patients in Europe and Israel

Since March 15th, 2020, 177 centres from Europe and Israel have joined the study, routinely reporting on the ECMO support they provide to COVID-19 patients. The mean annual number of cases treated with ECMO in the participating centres before the pandemic (2019) was 55. The number of COVID-19 patients has increased rapidly each week reaching 1531 treated patients as of September 14th. The greatest number of cases has been reported from France (n = 385), UK (n = 193), Germany (n = 176), Spain (n = 166), and Italy (n = 136) .The mean age of treated patients was 52.6 years (range 16–80), 79% were male. The ECMO configuration used was VV in 91% of cases, VA in 5% and other in 4%. The mean PaO2 before ECMO implantation was 65 mmHg. The mean duration of ECMO support thus far has been 18 days and the mean ICU length of stay of these patients was 33 days. As of the 14th September, overall 841 patients have been weaned from ECMO support, 601 died during ECMO support, 71 died after withdrawal of ECMO, 79 are still receiving ECMO support and for 10 patients status n.a. . Our preliminary data suggest that patients placed on ECMO with severe refractory respiratory or cardiac failure secondary to COVID-19 have a reasonable (55%) chance of survival. Further extensive data analysis is expected to provide invaluable information on the demographics, severity of illness, indications and different ECMO management strategies in these patients

Features of the Phase Preferences, Long- and Short-Range Order in <i>Ln</i>₂(WO₄)₃ (<i>Ln</i> = Gd, Dy, Ho, Yb) with Their Relation to Hydration Behavior

The effect of synthesis conditions on the features of the long- and short-range order of Ln2(WO4)3 (Ln = Gd, Dy, Ho, Yb) powders synthesized via coprecipitation of salts has been studied by a complex of physico-chemical techniques including synchrotron X-ray powder diffraction, X-ray absorption spectroscopy, Raman and infrared spectroscopy, and simultaneous thermal analysis. It was found that crystallization of amorphous precursors begins at 600 °C/3 h and leads to the formation of the monoclinic structure with sp. gr. C12/c1(15) for Ln2(WO4)3 (Ln = Gd, Dy) and with sp. gr. P121/a1(14) for Ln = Yb, whereas crystallization of Ho precursor requires even higher temperature. After annealing at 1000 °C, the P121/a1(14) phase becomes the dominant phase component for all heavy lanthanoid types except for Ln = Gd. It was shown that the Ln (Ln = Dy, Ho, and Yb) tungstates with the P121/a1(14) monoclinic structure correspond to trihydrates Ln2(WO4)3·3H2O formed due to a rapid spontaneous hydration under ambient conditions. It was concluded that the proneness to hydration is due to a specific structure of the P121/a1(14) phase with large voids available to water molecules. Modifications in the local structure of Ln-O coordination shell accompanying the structure type change and hydration are monitored using EXAFS spectroscopy

Influence of Synthesis Conditions on the Crystal, Local Atomic, Electronic Structure, and Catalytic Properties of (Pr_1−<i>x</i>Yb_<i>x</i>)₂Zr₂O₇ (0 ≤ <i>x</i> ≤ 1) Powders

The influence of Yb3+ cations substitution for Pr3+ on the structure and catalytic activity of (Pr1−xYbx)2Zr2O7 powders synthesized via coprecipitation followed by calcination is studied using a combination of long- (s-XRD), medium- (Raman, FT-IR, and SEM-EDS) and short-range (XAFS) sensitive methods, as well as adsorption and catalytic techniques. It is established that chemical composition and calcination temperature are the two major factors that govern the phase composition, crystallographic, and local-structure parameters of these polycrystalline materials. The crystallographic and local-structure parameters of (Pr1−xYbx)2Zr2O7 samples prepared at 1400 °C/3 h demonstrate a tight correlation with their catalytic activity towards propane cracking. The progressive replacement of Pr3+ with Yb3+ cations gives rise to an increase in the catalytic activity. A mechanism of the catalytic cracking of propane is proposed, which considers the geometrical match between the metal–oxygen (Pr–O, Yb–O, and Zr–O) bond lengths within the active sites and the size of adsorbed propane molecule to be the decisive factor governing the reaction route