Electroactive polymer membranes as substrates for point-of-care devices

Point-of-care devices (POC) are becoming essential for medical assistance in emergency situations or location with difficult access to medical infrastructures. In this work, innovative microfluidic substrates based on electroactive poly(vinylidene-co-trifluorethylene)-P(VDF-TrFE) with tuned morphologies and adequate physicochemical properties were developed using electrospinning and phase inversion techniques, as alternative to commercially available two-dimensional microfluidic substrates based mainly on cellulose. Their hydrophilicity was tuned using plasma treatments and barriers were implemented using wax printing to fabricate a design able to carry out glucose assays as a proof of concept.FCT- Fundação para a Ciência e Tecnologia: PTDC/EMD-EMD/28159/2017; SFRH/BD/140698/2018. Spanish Ministry of Economy and Competitiveness (MINECO): MAT2016-76039-C4-3-R. Basque Government Industry and Education Departments: ELKARTEK, HAZITEK and PIBA (PIBA-2018-06

A new linear parametrization for peak friction coefficient estimation in real time

The correct estimation of the friction coefficient in automotive applications is of paramount importance in the design of effective vehicle safety systems. In this article a new parametrization for estimating the peak friction coefficient, in the tire-road interface, is presented. The proposed parametrization is based on a feedforward neural network (FFNN), trained by the Extreme Learning Machine (ELM) method. Unlike traditional learning techniques for FFNN, typically based on backpropagation and inappropriate for real time implementation, the ELM provides a learning process based on random assignment in the weights between input and the hidden layer. With this approach, the network training becomes much faster, and the unknown parameters can be identified through simple and robust regression methods, such as the Recursive Least Squares. Simulation results, obtained with the CarSim program, demonstrate a good performance of the proposed parametrization; compared with previous methods described in the literature, the proposed method reduces the estimation errors using a model with a lower number of parameters

Artificial first-order phase transition in magnetized Nambu--Jona-Lasinio model with quark anomalous magnetic moment

Recently, first-order phase transitions have been predicted as an effect of the inclusion of quark anomalous magnetic moment (AMM) in the hot and magnetized Nambu--Jona-Lasinio model (NJL). These transitions appear in the chiral condensate for different combinations of AMM and magnetic fields and could lead to inverse magnetic catalysis. However, in this work, we show that the predicted first-order phase transitions are related to regularization-dependent issues. To show this, we explore, in the context of the vacuum magnetic regularization (VMR) scheme, two different scenarios: when mass-dependent (MD) and mass-independent (MI) terms are present in the subtraction of the divergences. In the MD case, as we increase the AMM value, it is observed the appearance of a non-massive minimum in the thermodynamical potential, which induces a first-order phase transition from the massive minimum. We argue that the MD terms must be avoided in order to satisfy the predictions of Lattice QCD, and we propose a MI solution that is valid in the limit which the magnetic fields are smaller than the squared of vacuum effective quark mass

Population biology and secondary production of the stout razor clam Tagelus plebeius (Bivalvia, Solecurtidae) on a sandflat in southeastern Brazil

The population biology and production of the stout razor clam Tagelus plebeius Lightfoot, 1786 were investigated on an intertidal sandflat on the southeast coast of Brazil (Enseada Beach, São Sebastião, state of São Paulo) between April 1997 and April 1998. Two rectangular sites of 50 X 10 m parallel to the waterline were established, site A (upper intertidal level) and site B (middle intertidal level), where the samples were taken in an 0.5 x 0.5 m quadrat. High abundances were recorded in winter and spring, with no significant differences between the sites. The high bivalve abundances were related to the presence of very fine homogeneous sediment with low salinities. Tagelus plebeius had negative allometric growth, characteristic of deep burrowers for the relationships DM/SL and AFDM/SL. Parameters of the modified von Bertalanffy growth function were: L∞ = 67.01 mm, K = 1.73 year-1, t0 = -0.11 year, C = 0.43, WP = 0.96. The instantaneous mortality (Z) was 3.12 year-1, relatively high in comparison to other tropical bivalve populations. Secondary production was 1.53 g AFDM m-2 year-1, with a P/B ratio reaching 1.37 year-1. This high turnover ratio (P/B) was related to a rapid population replacement, connected with the short life span and high mortality of the species.546

Natural based reusable materials for microfluidic substrates: The silk road towards sustainable portable analytical systems

Portable analytical systems are versatile tools for application in areas including biomedicine, biosecurity, food safety and environmental monitoring. This work contributes to the increasing demand for low-cost, environmentally friendly substrates for portable analytical systems by using natural Bombyx mori cocoons. Further, silk fibroin is also extracted from these cocoons and electrospun into oriented and randomly oriented fiber substrates. Oxygen plasma treatment is applied to improve their hydrophilicity. Fiber morphology, mechanical properties, porosity, thermal characteristics and surface contact angle are extensively characterized and the ability of the samples for passive capillary flows demonstrated. Plasma treated pressed cocoons show superhydrophilicity, capillary flow rates of 44.8 ± 3.75 mm.min-1, and high mechanical resistance with Young's modulus values up to 592.13 ± 19.83 MPa. The developed materials are used as substrates for the colorimetric quantification of three commonly scrutinized clinical analytes. Hydrophobic barriers are first wax-printed on all samples with a proper design and albumin assays are performed on all substrates. Further assays for uric acid and glucose quantification are successfully accomplished on the pressed cocoons after a simple in between washing step, with overall high coefficient of determination, proving the suitability of the developed materials as low-cost, sustainable and reusable microfluidic substrates.This work was supported by the Portuguese Foundation for Science and Technology (FCT) under strategic funding UID/FIS/04650/2020, UIDB/04436/2020, UIDP/04436/2020 and project PTDC/EMD-EMD/28159/2017 (POCI-01–0145-FEDER-028159). The authors also thank FCT for financial support under grants SFRH/BD/140698/2018 (R.B. P.), 2020.09218.BD (A.S.M.), 2020.04163.CEECIND (C.R.) and 2020.02304.CEECIND (V.F.C.). Finally, the authors acknowledge fund ing by Spanish State Research Agency (AEI) and the European Regional Development Fund (ERFD) through the project PID2019–106099RB C43/AEI/10.13039/501100011033 and from the Basque Government Industry Departments under the ELKARTEK program. Finally, the au thors also thank Dr. J. Borges and Prof. F. Vaz for experimental support.info:eu-repo/semantics/publishedVersio

Impact of air barriers application in LCA and LCC of naturally ventilated dwellings in mild climate regions

"Available online 17 November 2022"Assessing singular elements that constitute the air barrier of a building envelope is quite unfeasible in Life Cycle Assessment (LCA). The study of these solutions through this particular scope is often overlooked. Two major aspects contribute to it: the complexity of the relationships between elements and the reduced embodied impact of these materials in the overall construction or retrofitting works. This work uses LCA and Life Cycle Costing (LCC) to study the viability of applying two envelope air barrier solutions in dwellings with excessive air change rates and equipped with different heating systems. The application of air barrier solutions resulted in average energy consumption savings in urban terrain, almost half of those in rural terrain during the heating season. Environmental performance and life cycle costs revealed mechanically (MECH) fastened air barriers to outperform fluid (FLUID) applied ones. The median annualized cost of adopting a FLUID solution was almost four times that of a MECH solution. Dwellings equipped with electric radiators ranked first in the shortest average Energy Payback Period (EPP) and the highest average Reference Service Life (RSL) savings. With the current analysis, the adoption of MECH solutions is recommended, independently of the heating system the dwelling is equipped with.This work was financially supported by: Base Funding - UIDB/04708/2020 and Programmatic Funding - UIDP/04708/2020 of the CONSTRUCT - Instituto de I&D em Estruturas e Construções - funded by national funds through the FCT/MCTES (PIDDAC). The author would like to acknowledge the support of FCT - Fundação para a Ciência e a Tecnologia, the funding of the Doctoral Grant PD/BD/135162/2017, through the Doctoral Programme EcoCoRe. This work is supported by the European Social Fund (ESF), through the North Portugal Regional Operational Programme (Norte 2020) [Funding Reference: NORTE-06-3559-FSE-000176]

Bird extinctions and introductions are causing taxonomic and functional homogenization in oceanic islands

Humans are quickly reshaping species assemblages through the loss and gain of species at multiple scales. Extinctions and introductions are non-random events known to be contributing to taxonomic homogenization. However, it is not yet clear if they also promote functional homogenization. Here, we assess whether extinctions and introductions are leading to taxonomic and functional homogenization of 64 oceanic island bird assemblages, belonging to 11 archipelagos. Based on island lists of extinct and extant, native and introduced species and on species traits, we use probabilistic hypervolumes in trait space to calculate functional beta-diversity before and after extinctions and introductions. Bird extinctions and introductions promoted taxonomic and functional homogenization on most oceanic islands. These results follow our expectations, considering previous studies on taxonomic homogenization, the predictable link between taxonomic and functional diversity, and the trait similarity of many introduced species, often adapted to anthropogenic habitats, linked to the non-randomness of bird introductions on islands. Taxonomic homogenization was more common across than within archipelagos, also corroborating previous studies describing stronger homogenization on islands that are further apart and thus had distinctive native assemblages. Surprisingly, the widespread loss of species with similar traits, namely large flightless birds, often led to functional differentiation across archipelagos. However, this differentiation effect tended to be offset by the homogenizing effect of introductions. Functional homogenization increases the vulnerability to global changes, by reducing the variability of responses to disturbance and thus the resilience of ecosystem services, posing a threat to human societies on islands. Our results highlight subtle variations in taxonomic and functional beta-diversity of bird assemblages in oceanic islands, providing important insights to allow a better assessment of how anthropogenic changes might alter ecosystem functioning, which is vital to develop effective long-term conservation strategies. Read the free Plain Language Summary for this article on the Journal blog.Peer reviewe

Immunolocalization of HLA-DR and metallothionein on amalgam tattoos

Despite studies concerning toxic reactions related to amalgam components in the literature, few studies have been devoted to evaluate local noxious effects of amalgam tattoos (AT) on biological tissues. In addition, little is known about activation of inflammatory cells by mucosa-implanted amalgam debris. Tissue reaction to AT depends on the particle size. Human leukocyte antigen DR (HLA-DR) is an activation marker of inflammatory cells associated with antigen presentation. Metallothioneins (MT) are proteins involved with metal detoxication, including mercury and silver. The purpose of the present study was to investigate the immunolocalization of HLA-DR and MT in AT with large or powdered particles. Paraffin-embedded AT tissue blocks were sectioned and subjected to immunohistochemistry for HLA-DR and MT localization. The results demonstrated a dense mononuclear inflammatory infiltrate associated with large and powdered debris and positivity for HLA-DR and MT in inflammatory cells. While blood vessel walls and connective fibers impregnated with powdered particles were negative for HLA-DR, they were positive for MT. In addition, wherever epithelial basement membrane impregnation by powdered amalgam particles was observed, a strong positivity for MT was detected. These findings demonstrate that residual elements of AT still have noxious local effects over tissues. ___________________________________________________________________________________________________ RESUMOPoucos estudos têm investigado a toxicidade tecidual local das tatuagens por amálgama (TA), embora diversos trabalhos demonstrem efeitos nocivos desse material restaurador. Pouco se sabe sobre a ativação de células inflamatórias nesse tipo de lesão. A reação tecidual contra os restos de amálgama varia com o tamanho das partículas implantadas. O antígeno leucocitário humano DR (HLA-DR) está associado com a ativação de células inflamatórias, sendo relacionado à apresentação de antígeno. Metalotioneínas (MT) são proteínas envolvidas com neutralização de metais pesados, tais como mercúrio e prata. O objetivo do presente trabalho foi investigar a imunolocalização de HLA-DR e MT em TA compostas por depósitos teciduais de diferentes tamanhos. Cortes histológicos de lesões fixadas em formol e embebidas em parafina foram submetidos a técnica imunoistoquímica para a detecção dos antígenos mencionados. Os resultados demonstraram denso infiltrado inflamatório associado com partículas grandes ou pulverizadas, observando-se presença de células HLA-DR e MT positivas. Paredes de vasos sangüíneos e fibras de tecido conjuntivo impregnadas por restos de amálgama foram negativas para HLA-DR, mas positivas para MT. Impregnação da membrana basal por partículas de amálgama correspondia a forte positividade para MT no epitélio. Esses resultados demonstram a existência de efeitos nocivos locais das TA sobre os tecidos