Cholesterol-Containing Liposomes Decorated With Au Nanoparticles as Minimal Tunable Fusion Machinery

Membrane fusion is essential for the basal functionality of eukaryotic cells. In physiological conditions, fusion events are regulated by a wide range of specialized proteins, operating with finely tuned local lipid composition and ionic environment. Fusogenic proteins, assisted by membrane cholesterol and calcium ions, provide the mechanical energy necessary to achieve vesicle fusion in neuromediator release. Similar cooperative effects must be explored when considering synthetic approaches for controlled membrane fusion. We show that liposomes decorated with amphiphilic Au nanoparticles (AuLips) can act as minimal tunable fusion machinery. AuLips fusion is triggered by divalent ions, while the number of fusion events dramatically changes with, and can be finely tuned by, the liposome cholesterol content. We combine quartz-crystal-microbalance with dissipation monitoring (QCM-D), fluorescence assays, and small-angle X-ray scattering (SAXS) with molecular dynamics (MD) at coarse-grained (CG) resolution, revealing new mechanistic details on the fusogenic activity of amphiphilic Au nanoparticles (AuNPs) and demonstrating the ability of these synthetic nanomaterials to induce fusion regardless of the divalent ion used (Ca²⁺ or Mg²⁺). The results provide a novel contribution to developing new artificial fusogenic agents for next-generation biomedical applications that require tight control of the rate of fusion events (e.g., targeted drug delivery).     

Photocatalytic performance of Al and Nb-doped TiO2 nanoparticles prepared by microwave-assisted hydrothermal method

Microwave-assisted hydrothermal synthesis of aluminum (Al)-doped TiO₂ (ALT) and niobium (Nb)-doped TiO₂ (NBT) nanoparticles were carried out. Investigations were performed to examine the crystallinity, vibrational modes, surface morphology, and composition using X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS), respectively. The XRD study indicated the higher crystallinity of the ALT particles compared to the Al and Nb-doped TiO₂ (ALNBT) particles, and only the presence of the anatase phase was observed in all samples. As a result of doping, the Raman mode at ∼147 cm⁻¹ is found to be shifted toward a higher wavenumber for both samples. SEM analysis showed the spherical morphology of ALT and NBT nanoparticles. The elemental composition peaks of Al, titanium, Nb, and oxygen were noticed by EDS measurements. Furthermore, both prepared nanoparticles were used as photocatalytic materials. The Nb and Al-doped samples showed an improvement in the photocatalysis response in relation to the pure TiO₂ sample, in which Al-doped sample was able to decolorize 100% of rhodamine B in 75 min of analysis.     

The contribution of organizational culture,structure, and leadership factors in the digital transformation of SMEs: a mixed-methods approach

Cognition, Technology & Work - Contributing to the scarce literature on how companies can deal with their business model of digital transition, this work explores the digital transformation...     

Recycling Tetrafluoroethylene–Perfluoroalkyl Vinylether Copolymer (PFA) Using Extrusion Process

Tetrafluoroethylene–perfluoroalkyl vinylether copolymer (PFA) has a broad application ranging from biomedical and aerospace to corroding environments in the chemical industry. Despite a low share in end-of-life products, PFA processing can produce up to 30% of waste. Thus, understanding how recycled fluorinated polymers affect product performance is crucial to ensure primary recycling, besides economic and environmental reasons. In this paper, the utilization feasibility of PFA waste materials is investigated, i.e., recycled PFA (PFAr) in closed-loop recycling. The effect of PFAr loading (5–100 wt.%) on the thermal, mechanical, rheological, and color properties and chemical resistance are studied. Thermal properties and chemical resistance showed no significant changes in all ranges of PFAr content tested. The addition of higher loads of PFAr (≥50 wt.%) leads to a reduction in mechanical properties, particularly stress-strength analysis and elongation at break. However, elastic modulus and hardness have improved concurrently with an increase in the degree of crystallinity. The decrease in complex viscosity and yellowing of the samples occurred probably induced by a polymer chain degradation. Despite that, the addition of up to 10 wt.% of PFAr proved to be an effective alternative to reusing PFA residues based on mechanical recycling.     

Synthesis and properties of alkali-activated iron ore tailings blended with metakaolin

In this study, synthesis, microstructural characteristics, mechanical properties, and environmental compatibility of alkali-activated binders derived from iron ore tailings (IOT)—with partial replacement with metakaolin (MK)—were investigated. The binders were produced with a NaOH solution, IOT, and MK. A thermal cure at 100°C was used and the MK was applied as a partial replacement of IOT in three proportions (10, 20, and 30 wt%). The IOT-based specimens presented an average of 98.0 and 18.0 MPa at 7 days age of curing for compressive and flexural strength, respectively. The mechanical properties of the alkali-activated binders with MK decreased as the substitution ratio increased. By the microstructural analysis, it was found a zeolite-type phase in alkali-activated IOT, while in the binders blended with MK, three new mineral phases were identified. Furthermore, Fourier transform infrared, quantitative X-ray diffraction, and environmental analysis suggest that the Fe species present in IOT acted in the alkali-activation reaction.     

Fast synthesis of NaNbO3 nanoparticles with high photocatalytic activity for degradation of organic dyes

NaNbO₃ nanoparticles were obtained using the microwave-assisted hydrothermal method followed by heat treatment. It has been shown that heat treatment to increase the crystallinity of the material and modifies particle shape, from nanowires to nanograins. Nanowires with a diameter of approximately 35 nm and a length of tens of micrometers were obtained in the shortest time ever reported in the literature. Particles in the shape of nanograins with a diameter of approximately 35 nm were obtained by burning the nanowires. The photocatalytic activity of the nanoparticles was investigated through the photodegradation of Rhodamine B dye. Electronic structure analysis using density functional theory (DFT) along with experimental techniques was performed to help understand the photocatalytic activity of each sample. The obtained nanoparticles were highly favorable for photocatalytic applications, especially the nanograins, which degraded 100% of the dye in 50 min.     

Thermo-oxidative aging of acrylonitrile-butadiene rubber gaskets with real geometry used in plate heat exchangers

This study investigates the effects of aging on the physical and mechanical properties of commercially available acrylonitrile-butadiene rubber (NBR) gaskets while maintaining their original geometry. Thermo-oxidative cycles with 10 and 70 mm in length specimens were conducted from 80 to 170°C up to 180 days. The samples were analyzed employing compression set (CS), hardness, indentation modulus, cross-link density, total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), and thermogravimetry. The results showed that longer specimens presented better resistance to thermo-oxidative aging. Indentation results indicated regular oxygen permeability into the entire samples up to 110°C, while at higher temperatures, limited diffusion oxidation (DLO) effects promoted non-uniform aging. Time–temperature superposition (TTS) and Arrhenius methods were applied to predict the specimens' lifetime using CS as a failure criterion. Activation energies for 10 and 70 mm samples were 68.74 and 43.63 kJ mol⁻¹, respectively. Thus, the 70 mm specimen's lifetime was greater than 10 mm. For temperatures below ≈38°C, the response to the thermo-oxidative aging is independent of specimen length. Therefore, in determining the lifetime of gaskets with complex geometry, longer specimens are recommended to provide more reliable results than those suggested by the standards.     

Silicon Application to Soil Increases the Yield and Quality of Table Grapes (Vitis vinifera L.) Grown in a Semiarid Climate of Brazil

Silicon - Silicon (Si) acts to reduce biotic and abiotic stresses in plants. Herein, we aimed to assess the impact of an amorphous silica-based fertilizer (ASF) applied to soil on the yield,...