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The typical synthetic route of glassceramics involves the controlled crystallization of molten glasses through tailored thermal treatments. The resulting material is an amorphous phase which contains one or more crystalline phases. Glassceramics share peculiar characteristics of both their constituents. Thus, they show workability and machinability of glasses plus the functional and structural properties imparted by ceramic crystals. Among the many fields of application, glassceramics used as optical materials have more stringent requirements. A key feature in this type of products is to maintain a good transparency. Therefore, it is necessary to reduce crystal dimensions down to the nanometre scale and to minimize refractive index mismatch between host and guest so as to reduce scattering losses. Nonetheless the realization of glassceramic-based optical materials represents a fascinating way for the design of novel lasing medium, special optical fibres, and photo-responsive devices. In this context, solgel has been proved to be a valid method for the controlled precipitation of crystal nanoparticles (NPs) in amorphous pure silica matrix [3]. Here we present a bottom-up approach to produce glassceramics embedding prototypical wide bandgap semiconductors. Briefly, a ZnO NP suspension in an alcoholic solution is used as precursor for silica solgel. ZnO NPs were prepared by standard air-free Schlenk technique starting from zinc acetate as precursors and capped with oleic acid obtaining NPs of about 5 nm in size [2]. The ZnO capping was then stripped and exchanged with (3-Aminopropyl)triethoxysilane and suspended in ethanol. To start the gelification process, water and tetraethyl orthosilicate were added to the alcoholic suspension following well-established silica synthesis [3]. Finally, after complete gelification at 40°C for two weeks, xerogels underwent to thermal treatment up to ≈900 °C to obtain fully densified silica glassceramic containing dispersed nanoparticles. Transparent bulk samples with up to 1% mol of ZnO were obtained and characterized by UV-VIS and Raman spectroscopy, X-ray diffraction and electron microscopy. The results demonstrate that part of ZnO acted as nucleating agent for willemite (Zn2SiO4) and that, during gelation, there is a slight accumulation of NPs at the bottom of the xerogel originated by gravitational sedimentation. Figure 1. Raman spectra of bottom (red line) and top (blue line) side of the synthetized glassceramic with nominal composition of 1% mol ZnO in SiO2. The peaks marked with an asterisk are compatible with Zn2SiO4 in the willemite phase. Further studies will be carried out to extend this general synthesis strategy to other NPs and to establish the relationship between NP load and scattering losses.

Summary Background Mortality of patients with coronavirus disease 2019 (COVID-19), acute respiratory distress syndrome (ARDS), and systemic inflammation is high. In areas of pandemic outbreak, the number of patients can exceed maximum capacity of intensive care units (ICUs), and, thus, these individuals often receive non-invasive ventilation outside of the ICU. Effective treatments for this population are needed urgently. Anakinra is a recombinant interleukin-1 receptor antagonist that might be beneficial in this patient population. Methods We conducted a retrospective cohort study at the San Raffaele Hospital in Milan, Italy. We included consecutive patients (aged ≥18 years) with COVID-19, moderate-to-severe ARDS, and hyperinflammation (defined as serum C-reactive protein ≥100 mg/L, ferritin ≥900 ng/mL, or both) who were managed with non-invasive ventilation outside of the ICU and who received standard treatment of 200 mg hydroxychloroquine twice a day orally and 400 mg lopinavir with 100 mg ritonavir twice a day orally. We compared survival, mechanical ventilation-free survival, changes in C-reactive protein, respiratory function, and clinical status in a cohort of patients who received additional treatment with anakinra (either 5 mg/kg twice a day intravenously [high dose] or 100 mg twice a day subcutaneously [low dose]) with a retrospective cohort of patients who did not receive anakinra (referred to as the standard treatment group). All outcomes were assessed at 21 days. This study is part of the COVID-19 Biobank study, which is registered with ClinicalTrials.gov , NCT04318366 . Findings Between March 17 and March 27, 2020, 29 patients received high-dose intravenous anakinra, non-invasive ventilation, and standard treatment. Between March 10 and March 17, 2020, 16 patients received non-invasive ventilation and standard treatment only and comprised the comparison group for this study. A further seven patients received low-dose subcutaneous anakinra in addition to non-invasive ventilation and standard treatment; however, anakinra treatment was interrupted after 7 days because of a paucity of effects on serum C-reactive protein and clinical status. At 21 days, treatment with high-dose anakinra was associated with reductions in serum C-reactive protein and progressive improvements in respiratory function in 21 (72%) of 29 patients; five (17%) patients were on mechanical ventilation and three (10%) died. In the standard treatment group, eight (50%) of 16 patients showed respiratory improvement at 21 days; one (6%) patient was on mechanical ventilation and seven (44%) died. At 21 days, survival was 90% in the high-dose anakinra group and 56% in the standard treatment group (p=0·009). Mechanical ventilation-free survival was 72% in the anakinra group versus 50% in the standard treatment group (p=0·15). Bacteraemia occurred in four (14%) of 29 patients receiving high-dose anakinra and two (13%) of 16 patients receiving standard treatment. Discontinuation of anakinra was not followed by inflammatory relapses. Interpretation In this retrospective cohort study of patients with COVID-19 and ARDS managed with non-invasive ventilation outside of the ICU, treatment with high-dose anakinra was safe and associated with clinical improvement in 72% of patients. Confirmation of efficacy will require controlled trials. Funding None.

Rubber nanocomposites based on commercially available carbon allotropes and poly (1,4-cis-isoprene) (IR) were investigated. The carbon allotropes used were exfoliated graphene nanoplatelets (xGnPs) of type xg C750, carbon nanotubes (CNT-NC7000) and carbon black (CB-Printex xe2). The master batch based on CB-CNT was first prepared by mixing IR with CB and CNT. Final nanocomposites were obtained by adding xg C750 (from 2 to 15 phr). Role of increasing xg C750 loading in rubber matrix on dynamic-mechanical, thermal and electrical properties is reported. A stability of filler networking was evidenced as demonstrated through multi-hysteresis tests.

INTRODUCTION The production of rubber composites in tire industries involves a compounding phase and a curing process. To get highly performant materials, a homogeneous distribution of chemicals, reinforcing fillers and curing agents in rubber is required. Among them, ZnO is the most efficient worldwide employed curing activator, even though its poor dispersion in rubber matrix generally implies a high demand of ZnO. However, as ZnO undergoes leaching during tire life-cycle, the reduction of ZnO amount is becoming an urgent issue. In this context, the present work aims at improving the dispersion of ZnO in rubber nanocomposites, simultaneously reducing the employed ZnO amount. The impact of a different distribution was studied by comparing the vulcanization efficiencies and the mechanical properties of cured rubber nanocomposites prepared by using either a novel double function filler, ZnO/SiO2, constituted by ZnO nanoparticles (NPs) anchored to silica or the conventional micro-crystalline ZnO (m-ZnO). MATERIAL AND METHODS ZnO/SiO2 was prepared through a sol-gel procedure; ZnO NPs (3-5 nm) were anchored on silica particles, as demonstrated by the morphological and structural characterization. ZnO/SiO2 and m-ZnO were used to prepare two polyisoprene (IR) nanocomposites with a brabender. The compounds were calendered at 50°C and vulcanized in a compression molding press. A dynamic-mechanical analysis was performed at room temperature in tensile loading conditions: a 0.1% of amplitude dynamic strain was superimposed to a static deformation, at a frequency of 10 Hz. Uniaxial tensile tests were also performed at constant nominal strain rate and at room temperature, up to failure. RESULTS AND DISCUSSION ZnO/SiO2 showed higher curing efficiency in sulfur cross-linking of IR composites compared to m-ZnO and the cured materials presented dynamic-mechanical properties suitable for tire production at lower Zn amount. Besides, different mechanical behaviors were registered for the two rubber nanocomposites using a different distribution of ZnO. The higher curing efficiency of ZnO/SiO2 was explained by a more homogeneous distribution of zinc in rubber and higher accessibility of the Zn2+ ions during the process. The immobilization of ZnO NPs was responsible of a different reaction mechanism, which accounts for the higher cross-linking density and different mechanical properties of the cured material.

The present invention relates to a compound represented by the formula ( II ) : CB - O - ROS - GC - Zn ( II ) where CB repre sents the white filler , O represents one or more oxygen bridge bonds , ROS represents an organo - silane residue , GC represents one or more coordinating groups forming a chelate with zinc in ionic form represented by linear , branched or cyclic alkyl chains , comprising one or more heteroatoms inside or at the end of the alkyl chain , and Zn represents zinc in ionic form coordinated with the coordi nating groups , a process for the preparation thereof , and the use thereof in the vulcanisation process of elastomeric compounds.