Aim  To determine the relative contribution of species replacement and species richness differences to the emergence of beta‐diversity patterns.Innovation  A novel method that disentangles all compositional differences (β_cc, overall beta diversity) in its two components, species replacement (β_‐3) and species richness differences (β_rich) is proposed. The performance of the method was studied with ternary plots, which allow visualization of the influence of the relative proportions of shared and unique species of two sites over each metric. The method was also tested in different hypothetical gradients and with real datasets. The novel method was compared with a previous proposal based on the partitioning of overall compositional differences (β_sor) in replacement (β_sim) and nestedness (β_nes). The linear response of β_cc contrasts with the curvilinear response of β_sor to linear gradients of dissimilarity. When two sites did not share any species, β_sim was always 1 and β_‐3 only reached 1 when the number of exclusive species of both sites was equal. β_‐3 remained constant along gradients of richness differences with constant replacement, while β_sim decreased. β_rich had a linear response to a linear gradient of richness differences with constant species replacement, whereas β_nes exhibited a hump‐shaped response. Moreover, β_sim > β_nes when clearly almost all species of one site were lost, whereas β_‐3 < β_rich in the same circumstances.Main conclusions  The behaviour of the partition of β_cc into β_‐3 and β_rich is consistent with the variation of replacement and richness differences. The partitioning of β_sor into β_sim and β_nes overestimates the replacement component and underestimates richness differences. The novel methodology allows the discrimination of different causes of beta‐diversity patterns along latitudinal, biogeographic or ecological gradients, by estimating correctly the relative contributions of replacement and richness differences.

Pharmaceutical approaches based on nanotechnologies and the development of eye drops composed of the mucoadhesive polymers chitosan and hyaluronic acid are emerging strategies for the efficient treatment of ocular diseases. These innovative nanoparticulate systems aim to increase drugs’ bioavailability at the ocular surface. For the successful development of these systems, the evaluation of mucoahesiveness (the interaction between the ocular delivery system and mucins present on the eye) is of utmost importance. In this context, the aim of the present work was to investigate the mucoadhesivity of a novel nanoparticle eye drop formulation containing an antibiotic (ceftazidime) intended to treat eye infections. Eye drop formulations comprised a polymer (hydroxypropyl) methyl cellulose (HPMC) 0.75% (w/v) in an isotonic solution incorporating chitosan/sodium tripolyphosphate (TPP)-hyaluronic acid-based nanoparticles containing ceftazidime. The viscosity of the nanoparticles, and the gels incorporating the nanoparticles were characterized in contact with mucin at different mass ratios, allowing the calculation of the rheological synergism parameter (∆η). Results showed that at different nanoparticle eye formulation:mucin weight ratios, a minimum in viscosity occurred which resulted in a negative rheological synergism. Additionally, the results highlighted the mucoadhesivity of the novel ocular formulation and its ability to interact with the ocular surface, thus increasing the drug residence time in the eye. Moreover, the in vitro release and permeation studies showed a prolonged drug release profile from the chitosan/TPP-hyaluronic acid nanoparticles gel formulation. Furthermore, the gel formulations were not cytotoxic on ARPE-19 and HEK293T cell lines, evaluated by the metabolic and membrane integrity tests. The formulation was stable and the drug active, as shown by microbiological studies. In conclusion, chitosan/TPP-hyaluronic acid nanoparticle eye drop formulations are a promising platform for ocular drug delivery with enhanced mucoadhesive properties.

In the last few years, there has been an increasing demand for low-power and portable-energy sources due to the development and mass consumption of portable electronic devices. Furthermore, the portable-energy sources must be associated with environmental issues and imposed regulations. These demands support research in the areas of portable-energy generation methods. In this scope, piezoelectric materials become a strong candidate for energy generation and storage in future applications. This paper describes the use of piezoelectric polymers in order to harvest energy from people walking and the fabrication of a shoe capable of generating and accumulating the energy. In this scope, electroactive ß-polyvinylidene fluoride used as energy harvesting element was introduced into a bicolor sole prepared by injection, together with the electronics needed to increase energy transfer and storage efficiency. An electrostatic generator was also included in order to increase energy harvesting.

This paper presents a solution for energy microgeneration through energy harvesting by taking advantage of temperature differences that are converted into electrical energy using the Seebeck effect. A thermoelectric microconverter for energy scavenging systems that can supply low-power electronics was fabricated using thin films of bismuth and antimony tellurides. Thin films of n-type bismuth (Bi₂Te₃) and p-type antimony (Sb₂Te₃) tellurides were obtained by thermal coevaporation with thermoelectric figures of merit (ZT) at room temperature of 0.84 and 0.5 and power factors (PF × 10^-3 [W · K^-1 ·m-2]) of 4.87 and 2.81, respectively. The films were patterned by photolithography and wet-etching techniques. The goal for this thermoelectric microconverter is to supply individual electroencephalogram (EEG) modules composed by an electrode, processing electronics, and an antenna, where the power consumption ranges from hundredths of microwatts to a few milliwatts. Moreover, these wireless EEG modules allow patients to maintain their mobility while simultaneously having their electrical brain activity monitored.