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

Cluster Beam Deposition of Cu_2–<i>X</i>S Nanoparticles into Organic Thin Films

Bulk-heterojunction films composed of semiconductor nanoparticles blended with organic oligomers are of interest for photovoltaic and other applications. Cu_2–<i>X</i>S nanoparticles were cluster beam deposited into thermally evaporated pentacene or quaterthiophene to create bulk-heterojunction thin films. The nanoparticle stoichiometry, morphology, and chemistry within these all-gas phase deposited films were characterized by X-ray photoelectron spectroscopy (XPS) and electron microscopy. Cu_2–<i>X</i>S nanoparticles were (at most) only slightly copper-deficient with respect to Cu₂S; ∼2.5 nm diameter, unoxidized Cu_2–<i>X</i>S nanoparticles formed in both pentacene and quaterthiophene, as the matrix was not observed to impact the nanoparticle morphology or chemical structure. Cluster beam deposition allowed direct control of the nanoparticle stoichiometry and nanoparticle:organic ratio. Chemical states or Wagner plots were combined with other XPS data analysis strategies to determine the metal oxidation state, indicating that Cu­(I) was predominant over Cu­(II) in the Cu_2–<i>X</i>S nanoparticles

Acetylene Ion-Enhanced Bonding of PbS Nanoparticles to Quaterthiophene in Thin Films

Lead sulfide (PbS) nanoparticles of similar to 3-5 nm average diameter were codeposited into quaterthiophene (4T) organic films, which in some cases, were additionally modified by simultaneous 50 eV acetylene ion bombardment. The film composition and PbS-4T bonding were monitored by X-ray photoelectron spectroscopy (XPS) and laser desorption postionization mass spectrometry (LDPI-MS). S2p core-level XP spectra indicated that ion-modified films displayed enhanced bonding between 4T and PbS nanoparticles. LDPI mass spectra found thiophene fragments bound to PbS in ion-modified films. Computational simulations were used to investigate the mechanisms by which the incident particles chemically modified the thiophene-PbS nanoparticle interactions: molecular dynamics, density functional theory simulations were carried out on a-terthiophene (3T) analogues of 4T films interacting with (PbS)16 clusters. The simulations showed that, in the absence of acetylene ion modification, a weak charge transfer from the PbS cluster to the nearest 3T molecule occurred, suggestive of little interaction between intact organic matrix molecules and PbS nanoparticles. However, the simulations predicted the formation of a covalent bond between PbS and the oligothiophene film as a result of acetylene ion modification, in support of the experimental observations. These results help explain the recent observation of enhanced photoconductivity in these films upon ion modification (Majeslci, M. W.; et al. J. Vac. Sci. Technol. A 2012, 30, 04D109).11Nsciescopu

Acetylene Ion Enhanced Bonding of PbS Nanoparticles to Quaterthiophene in Thin Films

Lead sulfide (PbS) nanoparticles of ∼3–5 nm average diameter were codeposited into quaterthiophene (4T) organic films, which in some cases, were additionally modified by simultaneous 50 eV acetylene ion bombardment. The film composition and PbS–4T bonding were monitored by X-ray photoelectron spectroscopy (XPS) and laser desorption postionization mass spectrometry (LDPI-MS). S2p core-level XP spectra indicated that ion-modified films displayed enhanced bonding between 4T and PbS nanoparticles. LDPI mass spectra found thiophene fragments bound to PbS in ion-modified films. Computational simulations were used to investigate the mechanisms by which the incident particles chemically modified the thiophene–PbS nanoparticle interactions: molecular dynamics, density functional theory simulations were carried out on α-terthiophene (3T) analogues of 4T films interacting with (PbS)₁₆ clusters. The simulations showed that, in the absence of acetylene ion modification, a weak charge transfer from the PbS cluster to the nearest 3T molecule occurred, suggestive of little interaction between intact organic matrix molecules and PbS nanoparticles. However, the simulations predicted the formation of a covalent bond between PbS and the oligothiophene film as a result of acetylene ion modification, in support of the experimental observations. These results help explain the recent observation of enhanced photoconductivity in these films upon ion modification (Majeski, M. W.; J. Vac. Sci. Technol. A 2012, 30, 04D109)

Facile Energy Gap Tuning in Nanographene-MOFs

The utilization of metal-organic frameworks (MOFs) in photocatalysis applications requires light-responsive architectures with tunable optical bandgaps. Here, we demonstrate a facile approach to optical bandgap tuning via post-synthetic modifica-tions of pbz-MOF-1, a Zr-based MOF with polyphenylene ligands. A simple reaction of pbz-MOF-1 with FeCl3 was shown to induce three different chemical reactions of the ligands: oxidative dehydrogenation, chlorination and one/two electron oxi-dation of the ligands. The result of these reactions was a gradual decrease in the optical bandgap from 2.95 eV to as little as 0.69 eV. Time-resolved optical spectroscopy and electron paramagnetic resonance spectroscopy, coupled with density functional theory calculations provide insights into the mechanisms of bandgap tuning using chemical oxidation methods. The facile bandgap tuning report here has promising application in the utilization of photo-responsive MOFs in photocatalysis, sensing and other light-triggered applications

Metal impurity-assisted formation of nanocone arrays on Si by low energy ion-beam irradiation

Fabrication of nanocone arrays on Si surfaces was demonstrated using grazing incidence irradiation with 1 keV Ar+ ions concurrently sputtering the surface and depositing metal impurity atoms on it. Among three materials compared as co-sputtering targets Si, Cu and stainless steel, only the steel was found to assist the growth of dense arrays of nanocones at ion fluences between 1018 and 1019 ions/cm2 . The structural characterization of samples irradiated with these ion fluences using Scanning Electron Microscopy and Atomic Force Microscopy revealed that regions far away from co-sputtering targets are covered with nanoripples, and that nanocones popped-up out of the rippled surfaces when moving closer to co-sputtering targets, with their density gradually increasing and reaching saturation in the regions close to these targets. The characterization of the samples’ chemical composition with Total Reflection X-ray Fluorescence Spectrometry and X-ray Photoelectron Spectroscopy revealed that the concentration of metal impurities originating from stainless steel (Fe, Cr and Ni) was relatively high in the regions with high density of nanocones (Fe reaching a few atomic percent) and much lower (factor of 10 or so) in the region of nanoripples. Total Reflection Xray Fluorescence Spectrometry measurements showed that higher concentrations of these impurities are accumulated under the surface in both regions. X-ray Photoelectron Spectroscopy experiments showed no direct evidence of metal silicide formation occurring on one region only (nanocones or nanoripples) and thus showed that this process could not be the driver of nanocone array formation. Also, these measurements indicated enhancement in oxide formation on regions covered by nanocones. Overall, the results of this study suggest that the difference in concentration of metal impurities in the thin near-surface layer forming under ion irradiation might be responsible for the differences in surface structures