Effect of the TrFE Content on the Crystallization and SSA Thermal Fractionation of P(VDF-co-TrFE) Copolymers.

In this contribution, we study the effect of trifluoro ethylene (TrFE) comonomer content (samples with 80/20, 75/25, and 70/30 VDF/TrFE molar ratios were used) on the crystallization in P(VDF-co-TrFE) in comparison with a PVDF (Poly(vinylidene fluoride)) homopolymer. Employing Polarized Light Optical Microscopy (PLOM), the growth rates of spherulites or axialites were determined. Differential Scanning Calorimetry (DSC) was used to determine overall crystallization rates, self-nucleation, and Successive Self-nucleation and Annealing (SSA) thermal fractionation. The ferroelectric character of the samples was explored by polarization measurements. The results indicate that TrFE inclusion can limit the overall crystallization of the copolymer samples, especially for the ones with 20 and 25% TrFE. Self-nucleation measurements in PVDF indicate that the homopolymer can be self-nucleated, exhibiting the classic three Domains. However, the increased nucleation capacity in the copolymers provokes the absence of the self-nucleation Domain II. The PVDF displays a monomodal distribution of thermal fractions after SSA, but the P(VDF-co-TrFE) copolymers do not experience thermal fractionation, apparently due to TrFE incorporation in the PVDF crystals. Finally, the maximum and remnant polarization increases with increasing TrFE content up to a maximum of 25% TrFE content, after which it starts to decrease due to the lower dipole moment of the TrFE defect inclusion within the PVDF crystals.

Phase Transitions in Poly(vinylidene fluoride)/Polymethylene-Based Diblock Copolymers and Blends.

The crystallization and morphology of two linear diblock copolymers based on polymethylene (PM) and poly(vinylidene fluoride) (PVDF) with compositions PM23-b-PVDF77 and PM38-b-PVDF62 (where the subscripts indicate the relative compositions in wt%) were compared with blends of neat components with identical compositions. The samples were studied by SAXS (Small Angle X-ray Scattering), WAXS (Wide Angle X-ray Scattering), PLOM (Polarized Light Optical Microscopy), TEM (Transmission Electron Microscopy), DSC (Differential Scanning Calorimetry), BDS (broadband dielectric spectroscopy), and FTIR (Fourier Transform Infrared Spectroscopy). The results showed that the blends are immiscible, while the diblock copolymers are miscible in the melt state (or very weakly segregated). The PVDF component crystallization was studied in detail. It was found that the polymorphic structure of PVDF was a strong function of its environment. The number of polymorphs and their amount depended on whether it was on its own as a homopolymer, as a block component in the diblock copolymers or as an immiscible phase in the blends. The cooling rate in non-isothermal crystallization or the crystallization temperature in isothermal tests also induced different polymorphic compositions in the PVDF crystals. As a result, we were able to produce samples with exclusive ferroelectric phases at specific preparation conditions, while others with mixtures of paraelectric and ferroelectric phases.

Tocilizumab is associated with reduction of the risk of ICU admission and mortality in patients with SARS-CoV-2 infection

BackgroundIn some patients the immune response triggered by SARS-CoV-2 is unbalanced, presenting an acute respiratory distress syndrome which in many cases requires intensive care unit (ICU) admission. The limitation of ICU beds has been one of the major burdens in the management worldwide; therefore, clinical strategies to avoid ICU admission are needed. ObjectiveWe aimed to describe the influence of tocilizumab on the need of transfer to ICU or death in non-critically ill patients. MethodsA retrospective study of 171 patients with SARS-CoV-2 infection that did not qualify as requiring transfer to ICU during the first 24h after admission to a conventional ward, were included. The criteria to receive tocilizumab was radiological impairment, oxygen demand or an increasing of inflammatory parameters, however, the ultimate decision was left to the attending physician judgement. The primary outcome was the need of ICU admission or death whichever came first. Results77 patients received tocilizumab and 94 did not. The tocilizumab group had less ICU admissions (10.3% vs. 27.6%, P= 0.005) and need of invasive ventilation (0 vs 13.8%, P=0.001). In multivariable analysis, tocilizumab remained as a protective variable (OR: 0.03, CI 95%: 0.007-0{middle dot}1, P=0.0001) of ICU admission or death. ConclusionTocilizumab in the early stages of the inflammatory flare, could reduce ICU admissions and mechanical ventilation use. The mortality rate of 10.3% among patients receiving tocilizumab appears to be lower than other reports. Clinical implicationOur results suggest that tocilizumab administered to non-critically ill patients could reduce ICU admissions and mortality. Capsule summaryTocilizumab administered to non-critically ill patients with SARS-CoV-2 infection in the early stages of the inflammatory flare, could reduce an important number of ICU admissions and mechanical ventilation use.

Treatment of therapy-resistant sarcoidosis with adalimumab.

A possible role of tumor necrosis factor alpha (TNFalpha) in the pathomechanism of sarcoidosis must be considered in the analysis of this disorder since elevated concentrations of this cytokine have been found. In addition, TNFalpha expression could be demonstrated in sarcoid granulomata [1]. It is well known that TNFalpha plays a crucial role in granulomatous inflammation, e.g., in mycobacterial diseases [2]. Therefore, TNFalpha blockade is a potential approach in the therapy for sarcoidosis. Up to now, various cases of therapy-resistant sarcoidosis treated with anti-TNFalpha (infliximab and etanercept) have been reported [3-8]. Here, we describe successful treatment using adalimumab, a human recombinant immunoglobulin (Ig) G1 anti-TNF monoclonal antibody [9].