Search

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) has been widely used in patients with COVID-19, but uncertainty remains about the determinants of in-hospital mortality and data on post-discharge outcomes are scarce. The aims of this study were to investigate the variables associated with in-hospital outcomes in patients who received ECMO during the first wave of COVID-19 and to describe the status of patients 6 months after ECMO initiation.METHODS: EuroECMO-COVID is a prospective, multicentre, observational study developed by the European Extracorporeal Life Support Organization. This study was based on data from patients aged 16 years or older who received ECMO support for refractory COVID-19 during the first wave of the pandemic-from March 1 to Sept 13, 2020-at 133 centres in 21 countries. In-hospital mortality and mortality 6 months after ECMO initiation were the primary outcomes. Mixed-Cox proportional hazards models were used to investigate associations between patient and management-related variables (eg, patient demographics, comorbidities, pre-ECMO status, and ECMO characteristics and complications) and in-hospital deaths. Survival status at 6 months was established through patient contact or institutional charts review. This study is registered with ClinicalTrials.gov, NCT04366921, and is ongoing.FINDINGS: Between March 1 and Sept 13, 2020, 1215 patients (942 [78%] men and 267 [22%] women; median age 53 years [IQR 46-60]) were included in the study. Median ECMO duration was 15 days (IQR 8-27). 602 (50%) of 1215 patients died in hospital, and 852 (74%) patients had at least one complication. Multiorgan failure was the leading cause of death (192 [36%] of 528 patients who died with available data). In mixed-Cox analyses, age of 60 years or older, use of inotropes and vasopressors before ECMO initiation, chronic renal failure, and time from intubation to ECMO initiation of 4 days or more were associated with higher in-hospital mortality. 613 patients did not die in hospital, and 547 (95%) of 577 patients for whom data were available were alive at 6 months. 102 (24%) of 431 patients had returned to full-time work at 6 months, and 57 (13%) of 428 patients had returned to part-time work. At 6 months, respiratory rehabilitation was required in 88 (17%) of 522 patients with available data, and the most common residual symptoms included dyspnoea (185 [35%] of 523 patients) and cardiac (52 [10%] of 514 patients) or neurocognitive (66 [13%] of 512 patients) symptoms.INTERPRETATION: Patient's age, timing of cannulation (FUNDING: None.

The scheme of immunochromatographic competitive analysis with "external" specific antibodies is offered for the first time. The test strip includes all the necessary components for analysis (membranes, protein antigen conjugates, colored nanoparticles), except specific free unconjugated antibodies that are transferred to the buffer used for sample dilution. Thus, the concentrations of the antibodies and markers can be chosen independently, and dilution of the sample with buffer (a routine procedure for any immunochromatographic test) ensures pre-incubation of the antibodies with the sample. Both factors increase the sensitivity of the test. The proposed scheme has been proven to be effective for the determination of deoxynivalenol and T-2 toxin; detection limits of 500pg/mL and 50pg/mL, respectively, were achieved. This is an order of magnitude lower than the limits of detection of traditional tests using the same reagents. The analysis was conducted in water-organic extracts (20% methanol); the duration of the analysis is 10min (it's the same time as for a traditional test). The proposed approach is universal, and it can be used to detect a variety of compounds.

We provide a weak law of large numbers for arrays of nonnegative and pairwise negatively associated (in each row) random variables under a rather weak domination condition.

In this review, we describe the current state of development of immunochromatographic tests to detect toxic contaminants (e.g., mycotoxins, pesticides, and veterinary drugs) in agricultural products and foodstuffs. We consider the place of these tests among other methods used for food quality/safety assurance, as well as the specific requirements for immunochromatographic analyses of compounds in different food matrices. We discuss strategies to decrease the limit of detection and to conduct multi-parametric and quantitative analyses. We highlight some successfully commercialized analytical techniques and priorities for further research.

The validation of spectroscopic method for localization of the water plume around a coolant leak in ITER plasma chamber based on the excitation of coolant particles in plasma near wall is presented. The sensitivity of OH hydroxyl and Xe as minor admixtures to cooling water detection in different types of plasma discharges relevant to ITER tested in stellarator L-2M and hollow cathode glow discharge. The limit of sensitivity of water detection in hot plasma using OH* hydroxyl band is estimated as 3 × 10 −5 Pa m 3 s −1 and ∼1 × 10 −6 Pa m 3 s −1 for Xe. For glow discharge conditions measured sensitivity of OH* detection is equal to 3 × 10 −5 Pa m 3 s −1 .

An immunoanalytical system was developed for the determination of ochratoxin A with the use of a surface plasmon resonance (SPR) sensor amplified by the anti-species antibody–colloidal gold particle (CGP) conjugate. The use of the binding of immune complexes to the CGP–anti-species antibody conjugate leads to the SPR signal amplification by a factor of more than 10 and results in the 60 pg/mL limit of detection of ochratoxin A with an assay time of 30 min. These characteristics are superior to those obtained both in the conventional enzyme immunoassay with the use of the same reagents and the SPR assay with unmodified antibodies and specific antibodies conjugated to colloidal gold.

Standard enthalpies of formation of GdBaCo2−xMxO5.5 (M = Fe, Mn; x = 0, 0.2) from constituent oxides, Δ o x H i ∘ , and elements, Δ f H i ∘ , at 298 K were calculated using dissolution enthalpies of corresponding double perovskites. Both Δ o x H i ∘ and Δ f H i ∘ were found to decrease in the sequence of GdBaCo2O5.5, GdBaCo1.8Fe0.2O5.5 and GdBaCo1.8Mn0.2O5.5 indicating growth of relative thermodynamic stability of GdBaCo2O5.5 caused by the substitution of Fe or Mn for Co.

The notion of a separating time for a pair of measures on a filtered space is helpful for studying problems of (local) absolute continuity and singularity of measures. In this paper, we describe a certain canonical setting for continuous local martingales (abbreviated below as CLMs) and find an explicit form of separating times for CLMs in this setting.

Knowledge of the high-pressure and high-temperature elasticity of Fe–Ni alloy with low (5–25%) Ni content is crucial for geosciences since it is probably the major component of the cores of the terrestrial planets and the Moon. Here we present a study of a FeNi alloy with 22 at.% of Ni to 72 GPa and 715 K, using inelastic X-ray scattering (IXS) and X-ray powder diffraction from polycrystalline material. The X-ray diffraction (XRD) study revealed stability of the face centred cubic (fcc) over the hexagonal close packed (hcp) phase in the whole investigated pressure–temperature range. The study presents first investigations of elasticity of fcc phase of iron–nickel Fe0.78Ni0.22 alloy. The isothermal equations of state were derived at room temperature and at 715 K (K300 = 162(1) GPa, K ′ 300 = 4.97 ( 1 ) , V300 = 6.89(1) cm3/mol; K715 = 160(1) GPa, K ′ 715 = 4.97 ( 2 ) , V715 = 6.96(1) cm3/mol). Inelastic X-ray measurements allow the determination of the longitudinal acoustic wave velocity VP, and provide, combined with the measured equations of state, the full isotropic elasticity of the material. We found that within experimental errors our data follow the Birch's law. We did not observe any significant deviations for fcc Fe0.78Ni0.22 from elastic properties of pure ɛ-iron.

We have heated ferropericlase (Mg0.80Fe0.20)O to temperatures of over 2300 K at pressures of above 100 GPa to investigate the stability of the solid solution at elevated P, T conditions. The in situ X-ray study in laser-heated diamond anvil cells, as well as X-ray powder diffraction and chemical analysis of recovered samples, show that ferropericlase dissociates to magnesium oxide and ferrous oxide rich components. We demonstrate the importance of the combination of different analytical techniques for studies of solid-state chemical processes at extreme conditions.

The polarized absorption spectra of vanadium-doped forsterite single crystals in the range of 300–1600 nm (6250–33 000 cm−1) at 77 and 300 K have been investigated. All types of absorption centers were identified in the frame of crystal field theory. Crystal densities in dependence on vanadium concentration, measured by the precision floatation method, correlate with the results of structural computer modeling for different oxidation states of the dopant. It was shown that vanadium-doped forsterite crystals, grown by the Czochralski technique, contain mainly tetrahedrally coordinated V4+ ions. Partial oxidation of V4+ ions into V5+ state can be reached by oxidizing annealing of grown crystals. Octahedrally coordinated V3+ is responsible, apparently, for the absorption bands at 325, 375, 430 and 480 nm. The possibility to attribute the band at 1250 nm to V2+ ion is discussed.

The dependence of detection limits of ion-selective electrodes (ISEs) based on ionophores with phosphoryl-containing terminal groups on the nature and concentration of lipophilic anionic compounds was investigated. It was shown that by including superstoichiometric amounts of lipophilic anionic compounds into the membrane, the lower detection limit can be decreased significantly. A model describing the mechanism of the dependence of the lower detection limits on both the amount and nature of the lipophilic anionic additives used is presented.

A specific potential model of interionic interactions was derived in which the crystal structures of alkaline-earth cuprates were satisfactorily described and some of their physical properties were predicted. It was found that a harmonic three-particle O–Cu–O potential and some Morse-type contributions to the simple Buckingham-type Cu–O repulsive potential enable one to improve essentially the results of crystal structure modelling for cuprates. The obtained potential set seems to be well transferable for different cuprates, despite the variety in linkages of the CuO4 groups. In the present work this potential set model was applied in the crystal structure modelling for Ca2CuO3, CaCuO2, SrCuO3, (Sr1.19Ca0.73)Cu2O4, and BaCuO2. Some elastic and energetic properties of the compounds under question were predicted.

Theoretical predictions of the mixing properties of solid solutions can be made, in principle, via three different approaches: through the use of phenomenological, semi-classical atomistic, and ab initio techniques. Comparison of the results, obtained by application of all of the above-mentioned ways, is carried out for an example of the oxide solid solutions with the NaCl-type structure: CaO–MgO, CaO–MnO, MnO–NiO, and MgO–MnO. From this it is inferred that the predicted mixing energies for the whole range of compositions are generally in reasonable agreement with each other and with available experimental measurements for the systems under consideration. However, closer inspection shows marked systematic differences between the values of mixing energy and the structure relaxation parameters predicted with the use of different methods. In particular, this is due to the use of rather small and ordered unit cells for the atomistic and ab initio calculations. This allows one to make approximate estimates of disordering energies and propose some ways to improve the theoretical simulation of the solid solutions' mixing properties.

The dependence of the potentiometric selectivity of ion-selective electrodes (ISEs) based on phosphoryl-containing podands on concentration of the lipophilic compounds (sodium tetraphenylborate or potassium tetrakis-p-Cl-phenylborate) was investigated. It was demonstrated that the selectivity of the Ca- or/and Ba-selective electrodes over the alkali metals (AMs) and alkaline-earth metals (AEMs) increases with the lipophilic compound content. In case of AMs the changes of the selectivity is larger than for AEMs. It was shown that employment of the more lipophilic compound, namely, the potassium tetrakis-p-Cl-phenylborate, leads to the greater selectivity growth than for the sodium tetraphenylborate. A qualitative model which describes the potential-formation mechanism at the introduction of the lipophilic compounds in membrane composition was proposed.

Experimental data indicating increase of crystal-melt (fluid) partition coefficients in the range of microconcentrations of trace elements are reviewed and analyzed in detail. This concentration dependence of partition coefficients has been referred to as either deviations from Henry’s law or the trace-component trapping effect. A critical review of a variety of models proposed to explain this phenomenon is also given. It is shown that the most reasonable and developed of these models relate changes in trace element partition coefficient at low concentrations to interactions between the trace element ions and metastable lattice defects (i.e., linear and planar defects) at low temperatures or intrinsic point defects of thermal origin at higher temperatures. The mechanism of interaction between trace element substituent atoms and intrinsic defects is considered in detail, with particular consideration given to the creation of pair associates, coupled substitutions, and the influence of other impurities on the trace element dissolution. The models developed are fit to the available experimental data to provide descriptions of the dependence of partition coefficients on composition and to estimate the concentrations and free energies of formation of the intrinsic defects (i.e., vacancies and interstitial atoms) in a matrix crystal. Some probable geochemical applications and manifestations of the trapping effect are discussed. This leads to the conclusion that there is an urgent need for further consideration of the problem.

Dependence of the analytical characteristics (detection limits, DLs) and potentiometric selectivity K ij pot ) of the ion-selective electrodes (ISEs) based on phosphoryl-containing podands on the structures was investigated. It was demonstrated that the DL was determined by complex facilitated transfer energy. It was shown that the DLs of the majority of the ionophores weakly depend on the lipophilicity of the ionophores. Ionophore selectivity is determined by the difference of the facilitated transfer energies of both test and interfering ions and by the properties of the electrochemical system. Stability of complexes makes a major contribution to the energy accompanied with the transfer of the complex and is determined by the disposition of metaldonor atoms of ionophore bonds and by other properties of the electrochemical system, specifically, the dielectric permeability of the medium. Increasing the denticity by increasing the ethyleneglycol chain number leads to the transformation of Ca Ba to Ba Ca - selectivity . The introduction of the two-fold excess of the sodium tetraphenylborate (mol% to ionophore) in membrane composition results in increasing barium selectivity for alkali and alkaline-earth elements. An ISE for the determination of barium was prepared.

Maximum solubility of Sn 4+ ions in the spin glass Fe 2 Ti 1- x Sn x O 5 (pseudobrookite) corresponds to x = 0.22(3) at T = 1250°C, and Sn 4+ ions appear to occupy only 4c octahedral sites amongst the 4c and 8f sites. According to EPR data, the observed spin glass transition temperature T g depends on tin concentrations nonmonotonically. The T g values correlate with the measurement times typical of EPR and some other methods. This correlation is well approximated by the empirical Vogel-Fulcher law.

Temperature dependence of the composition of sphalerite in equilibrium with troilite + metallic iron has been determined experimentally from 400 to 840°C at 1 bar. The high-temperature runs (660–840°C) were conducted in evacuated silica tubes; a new version of the recrystallization in anhydrous halide flux technique was used for attaining equilibrium at 600-400°C. The zero-pressure solvus of sphalerite proved to be at higher FeS contents than was located by Barton and Toulmin (1966). Detailed calculations, based on updated thermochemical appraisal of the sphalerite (Zn,Fe)S solution, have shown the new solvus to be in apparent consistency with the high-pressure experimental data of Hutchison and Scott (1983 ). An improved calibration of the cosmobarometer is presented, based on our experimental results and those of Hutchison and Scott (1983) ; the calibration takes into account some inferences regarding thermodynamic properties of sphalerite solution and low-temperature polymorphism in FeS. Recently published metallographic cooling rates of iron meteorites (Saikumar and Goldstein, 1988) provide estimates of blocking temperatures for Fe diffusion in sphalerite, which fall in the range 205–217°C. Pressures of formation of these meteorites calculated from available sphalerite compositions range from 0 for Landes to 1.8 kbar for Toluca. The most reliable of the pressure estimates exhibit a linear relationship with wt% Ni of the meteorite.

In financial markets, liquidity is not constant over time but exhibits strong seasonal patterns. In this article we consider a limit order book model that allows for time-dependent, deterministic depth and resilience of the book and determine optimal portfolio liquidation strategies. In a first model variant, we propose a trading dependent spread that increases when market orders are matched against the order book. In this model no price manipulation occurs and the optimal strategy is of the wait region - buy region type often encountered in singular control problems. In a second model, we assume that there is no spread in the order book. Under this assumption we find that price manipulation can occur, depending on the model parameters. Even in the absence of classical price manipulation there may be transaction triggered price manipulation. In specific cases, we can state the optimal strategy in closed form.

A flow analyser with enhanced sampling frequency combining the features of flow-injection and continuous-flow analysis is described. Parameters of the analyser were optimized to ensure the highest rate of analysis allowed by the bubble-through flow cell with fluoride-selective electrodes. Fluoride was determined in 0.1-ml water samples with a sampling rate as high as 720 h−1 and a relative standard deviation better than 1%.

There is much evidence that X-ray measurements of sufficient accuracy reveal deviations from the linear dependence of unit-cell parameters on composition, i.e., departures from Vegard's rule. The dependence of such deviations on composition for a random solid solution with one substitutional position (Ax1 Bx2C is usually of a parabolic form: δa=x1x2σ where σ is positive. Many attempts to explain these observations are based on elastic models. It is known that less than 50% of the predictions of these models are correct. An alternative model under consideration is a simple geometric one. It is concerned with secondary atomic displacements around substitutional defects, i.e., shifts of the second nearest neighbors. The result is structurally dependent and the analysis deals with binary solid solutions of B1 (CN=6), B3 (CN=4), and B2 (CN=8) structure types. For instance, in sodium chloride structure-type solid solutions, the following simple equation is valid, δh=(3/2)x1x2(R)2/R, where R is the difference in interatomic distances of pure components and R is the average interatomic distance. Calculations for NaCl−KCl, NaCl−NaBr, KCl−KBr, and other systems are in good agreement with experimental data.

A fast-response flow cell with ion-selective electrodes was constructed for continuous-flow measurements in air-segmented streams without debubbling. The flow system was optimized for fluoride and chloride determinations. With a flow-rate of 4 ml min−1 a sampling rate of 480 h−1 was achieved for chloride determinations; the average relative standard deviation in all instances was better than 2%.