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•Different silk fibroin (SF) porous microstructures have been obtained by tuning solution, regeneration and post-processing•-Physical-chemical properties of the obtained materials ...depend on processing method.•The suitability of the microstructures for water remediation has been demonstrated.
The present work reports on the control of silk fibroin (SF) porous structures performance through various processing methods. The study includes the analysis of two dissolving techniques (CaCl2/H2O/EtOH ternary and LiBr/H2O binary solutions), three regeneration methods (gelation, lyophilization and gas foaming) and one post-processing (EtOH). In all the cases, followed steps lead to SF structures with porosity values above 94% and large surface areas. Also, results about samples microstructure, secondary organization, crystallinity and water behavior, reveal a direct correlation between processing and SF properties.
Thanks to the achieved progress, the SF varying porous structures were evaluated for metalloids (As5+ and As3+) and heavy metals (Cr6+ and Cr3+) adsorption, observing a direct relationship between samples processing and ionic species adsorption ability.
Thus, it is shown that the control of the properties of SF based porous structures through processing, represents a suitable and ecofriendly approach for the development of bio-based materials for environmental applications.
Low-dimensional magnetoelectric (ME) materials are attracting high attention both from the scientific and technological communities due to their interesting electrical, optical and mechanical ...properties allied to their novel applications in micro and nano smart-devices, drug delivery platforms, heterogeneous catalysis, tissue engineering, biosensors and bio-actuators, among others. Once the low dimensionality of these materials complicate the direct measurement of their performance at a large range of magnetic fields and high filler contents, this work theoretically evaluates low dimensional ME structures from spherical to ellipsoidal and fibre-shaped. The structures are based on CoFe2O4/poly(vinylidene fluoride) composites and the simulations are performed through the finite element method (FEM).
Results for 50 wt percentage (wt.%) CoFe2O4 content samples reveal ME coefficients of 182 V/cm at 684 Oe for the spheres and 4241 V/cm at a magnetic field of 208 Oe on the medium eccentricity (of 1200) ellipsoidal structure. These fibre shaped ellipsoids exhibit higher ME values than the spheres and the axisymmetric fibres: 1601 V/cm at 30 Oe for an ellipsoid with eccentricity of 3200. Further, the fibrilar structure strongly decreases the ME performance and operational magnetic field to 14.7 V/cm at 1.38 Oe.
These results establish the potential and limits, in terms of magnetic field and electric response, of the use of these composites and structures on technological ME device applications. Further, it demonstrates that suitable tuning of shape and dimensions allow to strongly increase ME response of the composites.
Magnetoelectric (ME) materials are becoming increasingly relevant in the development of new technologies for biomedical applications, sensors and actuators, among others. Mathematical models and ...simulations allow to optimize features and acquire fundamental knowledge on material properties to achieve innovative developments and devices. In this way, this work is focused on the simulation of both polymer-based and ceramic-based ME laminates, in order to evaluate the influence of their structure, mechanical, electrical and magnetic properties on the ME response. The effect of size and configuration has been evaluated in Vitrovac/poly (vinylidene fluoride)(PVDF) and Vitrovac/lead zirconate titanate (PZT) laminated composites. It has been established that the elastic properties and amorphous constitution of PVDF are key parameters governing its ME response, increasing its influence with increasing number of layers in the composite. Good agreement is established when comparing trends reported experimentally in the literature, presenting a curve that rapidly increases their αunit with increasing thickness ratio up to n = 0.3, when saturation is reached. Further, an optimal configuration for PZT multilayers is found, with external magnetostrictive phases and thickness ratio above 0.2, leading to a ME response of 86.7 V/cm. Finally, it has been established that PVDF configurations with external magnetostrictive phases (M-M configuration) show more stable behaviour (without the observation of random peaks) and trends over different number of layers, of about 11.5 V/cm, while P–P configurations present regions with random peaks, that is out of the expected trend and with a ME response (48 V/cm) that closer to the one obtained on ceramic multilayers.
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•The effect of different MOFs into PVDF-HFP separator membranes is studied.•The MOFs share a common building block and similar surface areas.•PVDF-HFP/MOF membranes integrate macro-, ...meso- and micropores in the same structure.•Post-morten analysis shows that the MOF structure collapses during battery cycling.•MOF based separators prevent capacity fading at high C-rates cycling.
The use of metal–organic frameworks in the separator membrane of lithium-ion batteries is an interesting subject of study for the next generation of energy storage devices. In this work, different poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) / metal–organic framework (MOF) based separators were prepared using three distinct MOFs, and the properties of these membranes were studied. The selected MOFs MOF-808, UiO-66-NH2 and MIL-125 are characterized by sharing a common building block (cluster or linker) and possessing relatively similar surface areas and topologies. It is observed that there are significant variations in the porous structure of the separator membrane upon the introduction of the different MOFs. The use of MOFs reduces the resistivity of the assembled battery half-cells, leading to excellent battery performance, with high discharge capacity (145 mAh.g−1 at C/8) and prolonged lifecycle, outperforming e conventional neat polymer separators due to the structure’s stabilization effect of the MOF. Among the selected MOFs, the best results are achieved with UiO-66-NH2 based on its improved charge/discharge values due to the low resistivity value of the half-cell. The post-morten analysis shows that the MOF structure collapses during battery cycling, but that this fact does not significantly affect battery performance, as the produced nanofillers keep their role of minimizing battery capacity fading. Thus, it is demonstrated that adding MOFs to a polymeric separator structure is beneficial and suitable for high-performance battery applications.
•Synthesised and characterised UiO-66, UiO-66-NH2, MIL-125 and MIL-125-NH2 MOFs.•Demonstrated 100 % NOx removal efficiency under UV light with NH2-functionalized MOFs.•Proposed a NOX removal two ...stages mechanism based in adsorption and photooxidation.•Achieved MOF immobilization in alginate/carrageenan for sustainable air filtration.•Immobilisation into Membrane maintains MOF's ability to remove NOX from air.
In the population increase and growing industrialization framework, NOx (NO and NO2) arises among the most important air pollutants responsible for various health and environmental conditions. Metal-organic frameworks, MOFs, are promising materials for NOx remediation.
This study investigates the removal of nitrogen oxides (NOx) using metal–organic frameworks (MOFs). MOFs UiO-66, UiO-66-NH2, MIL-125, and MIL-125-NH2 were synthesized and characterized. The surface area of the MOFs was quantified, showing values like 1118 m2/g for UiO-66-NH2 and 1424 m2/g for MIL-125-NH2. The NOx removal efficiency using the NH2 functionalized MOFs reached 100 % efficiency under UV light. Moreover, the immobilization of MIL-125-NH2 in carrageenan/alginate matrices was investigated, maintaining significant NOx reduction capabilities ∼ 80 %. This work also emphasizes the potential of MOFs by combining adsorptive and photocatalytic properties, providing insights into NOx capture and transformation mechanisms, and proposing a viable approach for sustainable air remediation technologies. This work paves the way for the successful applications of MOFs and MOF-modified membranes for air pollution mitigation.
Clinical data on which artificial intelligence (AI) algorithms are trained and tested provide the basis to improve diagnosis or treatment of infectious diseases (ID). We aimed to identify important ...data for ID research to prioritise efforts being undertaken in AI programmes.
We searched for 1,000 articlesfrom high-impact ID journals on PubMed, selecting 288 of the latest articles from 10 top journals. We classified them into structured or unstructured data. Variables were homogenised and grouped into the following categories: epidemiology, admission, demographics, comorbidities, clinical manifestations, laboratory, microbiology, other diagnoses, treatment, outcomes and other non-categorizable variables.
4,488 individual variables were collected, from the 288 articles. 3,670 (81.8%) variables were classified as structured data whilst 818 (18.2%) as unstructured data. From the structured data, 2,319 (63.2%) variables were classified as direct-retrievable from electronic health records-whilst 1,351 (36.8%) were indirect. The most frequent unstructured data were related to clinical manifestations and were repeated across articles. Data on demographics, comorbidities and microbiology constituted the most frequent group of variables.
This article identified that structured variables have comprised the most important data in research to generate knowledge in the field of ID. Extracting these data should be a priority when a medical centre intends to start an AI programme for ID. We also documented that the most important unstructured data in this field are those related to clinical manifestations. Such data could easily undergo some structuring with the use of semi-structured medical records focusing on a few symptoms.
Magnetoelectric (ME) composites exhibiting strain-mediated coupling are gaining increasing interest for applications. The most interesting ones are composed of piezoelectric polymers and ...magnetostrictive particles. In particular, low dimensional ME materials, such as the ones in the form of micro- and nano-spheres, show strong potentials for improved energy harvesters with higher volume efficiency, sensors and actuators. Nevertheless the ME characterization of such low dimensional ME structures remain a difficult and challenging task and, therefore, the use of mathematical models and simulations are an interesting and viable option to better understand and tailor materials towards applications.
In this context, the ME coupling on microspheres based on piezoelectric poly(vinylidene fluoride) (PVDF) and magnetostrictive CoFe2O4 (CFO) particles was theoretically studied based on Finite Element Methods (FEM). The effect of sphere size and filler content on the ME response was evaluated, showing that the ME response of CFO/PVDF microspheres is strongly influenced by the magnetic field intensity, sphere diameter and CFO content, being the highest ME response achieved on composite sphere with 90 wt% of CFO and 1.2 μm.
This paper develops a computational framework with unfitted meshes to solve linear piezoelectricity and flexoelectricity electromechanical boundary value problems including strain gradient elasticity ...at infinitesimal strains. The high-order nature of the coupled PDE system is addressed by a sufficiently smooth hierarchical B-spline approximation on a background Cartesian mesh. The domain of interest is embedded into the background mesh and discretized in an unfitted fashion. The immersed boundary approach allows us to use B-splines on arbitrary domain shapes, regardless of their geometrical complexity, and could be directly extended, for instance, to shape and topology optimization. The domain boundary is represented by NURBS, and exactly integrated by means of the NEFEM mapping. Local adaptivity is achieved by hierarchical refinement of B-spline basis, which are efficiently evaluated and integrated thanks to their piecewise polynomial definition. Nitsche’s formulation is derived to weakly enforce essential boundary conditions, accounting also for the non-local conditions on the non-smooth portions of the domain boundary (i.e. edges in 3D or corners in 2D) arising from Mindlin’s strain gradient elasticity theory. Boundary conditions modeling sensing electrodes are formulated and enforced following the same approach. Optimal error convergence rates are reported using high-order B-spline approximations. The method is verified against available analytical solutions and well-known benchmarks from the literature.
•Flexoelectricity is simulated with unprecedented generality and efficiency.•Nitsche’s method is developed for higher-order electromechanics.•Optimal convergence in non-trivial geometries is achieved.•Design and optimization of electromechanical devices with general geometries is enabled.
Silver vanadium oxide (SVO) and Silver Vanadium Oxide/Vanadium Oxide (SVO@VO) composite hydrogels are formed from the self-entanglement of β-AgVO
nanoribbons and slightly reduced vanadium oxide (VO) ...(V
V
O
) nanoribbons; respectively. Starting from randomly distributed nanoribbons within hydrogels, and after a controlled drying process, a homogeneous xerogel system containing tuneable SVO : VO ratios from 1 : 0 to 1 : 1 can be obtained. The precise nanoribbons compositional control of these composite system can serve as a tool to tune the electrical properties of the xerogels, as it has been demonstrated in this work by impedance spectroscopy (IS) experiments. Indeed, depending on the composition and temperature conditions, composite xerogels can behave as electronic, protonic or high temperature ionic conductors. In addition, the electric and protonic conductivity of the composite xerogels can be enhanced (until a critical irreversible point), through the temperature triggered charge carrier creation. As concluded from thermogravimetry, IR, UV-Vis and EPR spectroscopy studies, besides the SVO : VO ratio, the thermal induced oxidation/reduction of V
to V
, and thermally triggered release of strongly bonded water molecules at the nanoribbon surface are the two key variables that control the electric and ionic conduction processes within the SVO and composite SVO/VO xerogels.
BACKGROUND AND OBJECTIVEAmong the main causes of blindness and severe vision loss are age-related macular degeneration, diabetic macular oedema, and retinal vein occlusion. The «Do Not Do» ...recommendations are strategies to improve quality of care and optimise healthcare costs. The aim of this study was to establish, by consensus, practices of low value in the above-mentioned pathologies, in addition to estimating their occurrence. MATERIALS AND METHODSMixed methods study including a first phase of consensus of a multidisciplinary panel of experts using the Nominal Group technique. In the second phase, a retrospective observational study was conducted, by conducting a review of medical records. RESULTSA total of 7 recommendations were established for age-related macular degeneration, 4 for diabetic macular oedema, and 5 for retinal vein occlusion. A total of 1,012 medical records were reviewed by the 4 participating hospitals. The review of medical records revealed that agreed «Do Not Do's» occurred in a range between 0.6% and 31.4% of the cases included in the study. CONCLUSIONSThis study identified «Do Not Do» recommendations in these pathologies that occur relatively often in clinical practice. It is necessary to review the healthcare processes that will enable these practices to be eradicated, and the quality of care to be improved.
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