Treatment with tocilizumab or corticosteroids for COVID-19 patients with hyperinflammatory state: a multicentre cohort study (SAM-COVID-19)

Objectives: The objective of this study was to estimate the association between tocilizumab or corticosteroids and the risk of intubation or death in patients with coronavirus disease 19 (COVID-19) with a hyperinflammatory state according to clinical and laboratory parameters. Methods: A cohort study was performed in 60 Spanish hospitals including 778 patients with COVID-19 and clinical and laboratory data indicative of a hyperinflammatory state. Treatment was mainly with tocilizumab, an intermediate-high dose of corticosteroids (IHDC), a pulse dose of corticosteroids (PDC), combination therapy, or no treatment. Primary outcome was intubation or death; follow-up was 21 days. Propensity score-adjusted estimations using Cox regression (logistic regression if needed) were calculated. Propensity scores were used as confounders, matching variables and for the inverse probability of treatment weights (IPTWs). Results: In all, 88, 117, 78 and 151 patients treated with tocilizumab, IHDC, PDC, and combination therapy, respectively, were compared with 344 untreated patients. The primary endpoint occurred in 10 (11.4%), 27 (23.1%), 12 (15.4%), 40 (25.6%) and 69 (21.1%), respectively. The IPTW-based hazard ratios (odds ratio for combination therapy) for the primary endpoint were 0.32 (95%CI 0.22-0.47; p < 0.001) for tocilizumab, 0.82 (0.71-1.30; p 0.82) for IHDC, 0.61 (0.43-0.86; p 0.006) for PDC, and 1.17 (0.86-1.58; p 0.30) for combination therapy. Other applications of the propensity score provided similar results, but were not significant for PDC. Tocilizumab was also associated with lower hazard of death alone in IPTW analysis (0.07; 0.02-0.17; p < 0.001). Conclusions: Tocilizumab might be useful in COVID-19 patients with a hyperinflammatory state and should be prioritized for randomized trials in this situatio

Magnetite nanoparticles as adsorbent material for Cu2+ ions from aqueous solution

"Cu2+ ions can cause serious injuries to human health, at both high and low concentrations. Therefore, it is important not only to remove Cu2+ ions from aqueous media, but also to develop analytical methods for their accurate determination at low concentrations. Magnetite is one of the most used sorbents for Cu2+ removal. This work aims at synthesizing magnetite nanoparticles and at evaluating their adsorption capacity toward Cu2+ ions in aqueous solution by means of atomic absorption spectroscopy. Magnetite nanoparticles were characterized by means of a vibrational magnetometer, Fourier transformer infrared spectrum (FTIR), x-ray diffraction (XRD) and Thermal gravimetric analysis (TGA). Magnetic nanoparticles showed Ms values of 52 and 62 emu/g. By taking into consideration the precipitation of Cu(OH)2 as a function of pH in the evaluation of the adsorption capacity of magnetite, we found that the maximum Cu2+ adsorption occurs at pH = 7 and that the adsorption equilibrium of the two samples is reached at 490 and 445 min. The use of blank solution avoids the overestimation of the adsorption capacity due to the presence of insoluble Cu(OH)2. Finally, two models are considered as a liquid/solid phase reaction, pseudo-first- and pseudo-second-order reaction. Batch adsorption kinetics agrees with a pseudo-second-order model, suggesting that chemisorption is the rate-limiting step.

BiFeO3 codoping with Ba, La and Ti: Magnetic and structural studies

"Conventional solid state reaction method, from oxides and carbonates, was employed to prepare bismuth (Bi)-based multiferroic systems. The undoped BiFeO3 (BFO) and the codoped system with Ba, La and Ti (Bi1?xBaxFe1?yTiyO3, Bi1?x?zBaxLazFe1?yTiyO3) with x,y,z=0.1 were prepared stoichiometrically and sintered at two different temperatures. The structural and magnetic properties were investigated at room temperature. XRD measurements confirm the obtaining of the rhombohedral perovskite structure of the BFO family system. For the undoped system, some reflections of undesired phases are present for two different sintering temperatures, while for the doped system only one phase is present for both temperatures. The magnetic characterization at room temperature revealed remarkable differences between the ceramic samples. The results show that for undoped BFO system, spontaneous magnetization is not observed at room temperature. Nevertheless, in doped one, a well-defined ferromagnetic behavior is observed at room temperature, possible, due to the suppression of the spatially modulated spin structure of BFO promoted by the reduction of the rhombohedral distortion and the weakening of the Bi–O bonds. The XPS results confirm the presence of oxygen vacancies and the coexistence of Fe3+ and Fe2+ in all the studied samples. Calorimetric measurements reveal that the dopant incorporation has not a direct effect in Néel temperature but possibly yes in ferroelectric-paraelectric transition.

Propiedades magnéticas y distribución de tamaños de nanopartículas de magnetita recubiertas con ácido oleico

"The particle size and particle size distribution are very important to biomedical applications because the uptake of nanoparticles is strongly dependent on particle size. Oleic acid coated magnetite nanoparticles were synthesized by using chemical co-precipitation. The average particle size and particle size distribution measured by different techniques are compared. The crystallite sizes estimated by X-Ray Diffraction (9.32 nm) and the average particle size calculated by Transmission Electron Microscopy (9.46 nm) are very similar. Atomic Force Microscopy revealed an average diameter of 1030 nm, which is bigger than estimated by other techniques due to the oleic acid layer covering the nanoparticles. The distribution of magnetic sizes of nanoparticles was also estimated through the magnetic response of the system, using the Langevin model (9.11 nm). Anisotropy constant (Ka = 4.74 *105 erg/cm3) and blocking temperature (TB = 118 K) were obtained.