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Rice is the second most important cereal crop and is vital for the diet of billions of people. However, its consumption can increase human exposure to chemical contaminants, namely mycotoxins and metalloids. Our goal was to evaluate the occurrence and human exposure of aflatoxin B1 (AFB1), ochratoxin A (OTA), zearalenone (ZEN), and inorganic arsenic (InAs) in 36 rice samples produced and commercialized in Portugal and evaluate their correlation. The analysis of mycotoxins involved ELISA, with limits of detection (LODs) of 0.8, 1 and 1.75 μg kg−1 for OTA, AFB1, and ZEN, respectively. InAs analysis was carried out by inductively coupled plasma mass spectrometry (ICP-MS; LOD = 3.3 μg kg−1). No sample showed contamination by OTA. AFB1 was present in 2 (4.8%) samples (1.96 and 2.20 μg kg−1), doubling the European maximum permitted level (MPL). Concerning ZEN, 88.89% of the rice samples presented levels above the LOD up to 14.25 µg kg−1 (average of 2.75 µg kg−1). Regarding InAs, every sample presented concentration values above the LOD up to 100.0 µg kg−1 (average of 35.3 µg kg−1), although none surpassed the MPL (200 µg kg−1). No correlation was observed between mycotoxins and InAs contamination. As for human exposure, only AFB1 surpassed the provisional maximum tolerable daily intake. Children were recognized as the most susceptible group. [ABSTRACT FROM AUTHOR]

The present study investigates the magnetic properties of spherical monodispersed maghemite (γ-Fe2O3) nanoparticles coated with multiple silica (SiO2) layers of different thicknesses, forming core-shell multifunctional nanomaterials. This study was performed using a combination of local probe techniques (Mössbauer spectrometry) and magnetization measurements. At room temperature, both techniques confirm the superparamagnetic state of the samples, even after being coated with the SiO2 shells. The zero-field-cooling-field-cooling magnetization curves of the silica-coated γ-Fe2O3 nanomaterials with different shell thicknesses allow the evaluation of the intensity of the interparticle dipole-dipole interactions. We estimate the interparticle energy within the framework of dipolar interaction models and relate it with the hyperfine parameters. We further observe that this dipole-dipole interaction increases the superparamagnetic energy barrier, which largely depends on the interparticle distance. Finally, we consider the effect of spin canting at the surface ('dead layer') of uncoated γ-Fe2O3 nanoparticles manifested by a layer of ∼0.5(1) nm. [ABSTRACT FROM AUTHOR]

The growth of aquaculture over the past few years is widely recognized as one of the main sources of antibiotics, mainly fluoroquinolones (FQ) and tetracyclines (TC), in the aquatic environment, consequently, increasing the risk of the emergence of antibiotic bacterial resistance and promoting the spread of resistant genes. This study aimed to (1) develop and validate a multiresidue method for determination and quantification of ciprofloxacin (CIP), difloxacin (DIFL), enrofloxacin (ENR), norfloxacin (NOR), sarafloxacin (SARA), and oxytetracycline (OXY) in aquaculture waters and surrounding water bodies and (2) provide the first Portuguese data to utilize in assessment of risk of adverse effects. In addition, the potential environmental impact posed by these antibiotics to aquatic organisms, belonging to different trophic levels, when exposed to the studied aquaculture waters was also assessed. The analytical strategy comprised of solid-phase extraction (SPE) through Oasis HLB cartridges, and detection and quantification by liquid chromatography with tandem mass spectrometry (LC/MSn). Method detection limits (MDL) and method quantification limits (MQL) were in the range of 0.7–3 ng/L and 2.4–10 ng/L, respectively. Recoveries varied between 57.4 and 122.8%. The method was applied to 31 water samples collected from an aquaculture and surrounding water bodies located in north of Portugal. Residues of all antibiotics, except SARA and DIFL, were detected at concentrations ranging from 3 to 75.1 ng/L. Norfloxacin was the antibiotic present at highest frequency and concentration. Regarding the environmental impact assessment (EIA), a risk quotient higher than 1 was observed for NOR. [ABSTRACT FROM PUBLISHER]

The influence of dynamics and sample shape on the magnetic hysteresis in first-order magnetocaloric metamagnetic LaFe13- xSi x with x = 1.4 is studied. In solid-state magnetic cooling, reducing magnetic and thermal hysteresis is critical for refrigeration cycle efficiency. From magnetization measurements, it is found that the fast field-rate dependence of the hysteresis can be attributed to extrinsic heating directly related to the thickness of the sample and the thermal contact with the bath. If the field is paused partway through the transition, the subsequent relaxation is strongly dependent on shape due to both demagnetizing fields and thermal equilibration; magnetic coupling between adjacent sample fragments can also be significant. Judicious shaping of the sample can both increase the onset field of the ferromagnetic-paramagnetic (FM-PM) transition but have little effect on the PM-FM onset, suggesting a route to engineer the hysteresis width by appropriate design. In the field-paused state, the relaxation from one phase to the other slows with increasing temperature, implying that the process is neither thermally activated or athermal; comparison with the temperature dependence of the latent heat strongly suggests that the dynamics reflect the intrinsic free energy difference between the two phases. [ABSTRACT FROM AUTHOR]

[Display omitted] • A dual-functional textile device with energy storage and fluorescence was produced. • A fluorescent redox-active solid-gel electrolyte based on ZnS:Mn was prepared for the first time. • The hybrid textile supercapacitor exhibited enhanced energy storage performance. • Excellent cycling stability (100%) after 8000 charge/discharge cycles. • The device could easily power a sensor for ~12 min when charged during 10 s. The evolution of wearable technologies boosted the development of energy storage textiles that can be charged faster and store energy for longer time. Achieving multifunctionality on textiles is a key milestone towards higher value-added smart products. Herein, we report on the fabrication of a novel dual-functional textile device merging enhanced energy storage performance with optical properties. A redox-active solid-gel electrolyte based on fluorescent manganese(II)-doped zinc(II) sulfide was for the first time used to endow the dual functionality to the device when combined with MWCNT-coated textile electrodes. The textile electrodes were prepared through an eco-sustainable straightforward dip-pad-dry process using a natural cotton fabric substrate. The fluorescent hybrid textile supercapacitor exhibited enhanced energy storage performance relative to the EDLC-type analogue containing the undoped electrolyte, namely 20% higher working voltage (1.64 V), 48% higher energy density (1.63 W h kg−1) and 74% higher power density (641.6 W kg−1). Additionally, it presented excellent cycling stability (100%) after 8000 charge/discharge cycles. The device exhibited intense yellow-orange fluorescence under UV light, while preserving the energy storage functionality. This work demonstrated the versatility of this type of devices for dark environment applications, namely in reflective/safety electronic clothing for nighttime users. [ABSTRACT FROM AUTHOR]

Breast milk is considered the ideal form of nutrition for newborns and infants. However, it can carry over contaminants, namely mycotoxins, with biological effects to which this population is particularly vulnerable. Human biomonitoring and surveillance programs are particularly scarce in low-income countries, where food security is a more urgent priority in comparison with food safety. This pilot survey aims to assess exposure of breastfed infants to aflatoxin M1 (AFM1), zearalenone (ZEN), and ochratoxin A (OTA) in Angola, and to evaluate the main socio-demographical and food consumption determinants of lactating mothers. All 37 breast milk samples analyzed are found to be contaminated with ZEN and OTA, although none are found contaminated with AFM1. Contamination levels are lower than previously reported for ZEN but higher in the case of OTA. A significant association between ZEN levels in breast milk and the consumption of cookies by the lactating mothers is found. As for OTA, higher levels are observed in the milk from mothers with younger infants, for which high estimated daily intake (EDI) is determined. As far as the authors are aware, this is the first survey of the occurrence of mycotoxins in breast milk in Angola, so further human biomonitoring works should follow, given that mycotoxins are a global health issue that directly impact the health of populations. [ABSTRACT FROM AUTHOR]

Carmines (E120) are used worldwide as natural food colouring agents of animal origin, with a widespread application, including yoghurts. Despite being considered safe for human health, carmines are known to cause allergic reactions. Our goal was to evaluate the presence of carmines in different yoghurts with a label declaration of E120, purchased in Portugal, and, for the first time, to assess the human risk. The analytical methodology, recommended by JECFA, was based on acid hydrolysis of the samples followed by spectrophotometric UV-Vis analysis at 494 nm. This methodology allowed for a limit of quantification (LOQ) of 39.0 mg/kg and recovery rates higher than 97.7%. All the samples had carmines at levels above the LOQ, ranging between 43.8 and 193.8 mg/kg, with an average of 125.2 ± 34.5 mg/kg. In total, 8 (26.7%) samples exceeded the European Union (EU) maximum permitted level (MPL) established for carmines in this foodstuff, 150 mg/kg. Solid yoghurts presented higher average levels, 137.2 mg/kg, when compared to liquid samples, 107.2 mg/kg, with a significant statistical difference (p= 0.0236) being observed. No significant statistical difference was observed between white and private labels, whose average levels were very similar, 125.4 vs 125 mg/kg, respectively. Although some samples were above the allowable values, the estimated daily intake (EDI), designed for the different scenarios of different yoghurt types, did not exceed the established ADI, 5 mg/kg bw/day. According to the obtained results, carmine ingestion through the consumption of yoghurt poses low risk to the Portuguese consumers. However, children were the most vulnerable population group with a calculated risk value of up to 10% considering the mean content scenario. These first findings point out the need to reinforce surveillance programmes and monitoring studies, contributing to an increased awareness regarding carmine exposure, however it must be emphasised that yoghurt has evident nutritional benefits depending on a healthful consumer choice. [ABSTRACT FROM AUTHOR]

Microparticles of corn starch and chitosan crosslinked with glutaraldehyde, produced by the solvent exchange technique, are studied as reinforcement fillers for thermoplastic corn starch plasticized with glycerol. The presence of 10% w/w chitosan in the microparticles is shown to be essential to guaranteeing effective crosslinking, as demonstrated by water solubility assays. Crosslinked chitosan forms an interpenetrating polymer network with starch chains, producing microparticles with a very low solubility. The thermal stability of the microparticles is in agreement with their polysaccharide composition. An XRD analysis showed that they have crystalline fraction of 32% with Va-type structure, and have no tendency to undergo retrogradation. The tensile strength, Young's modulus, and toughness of thermoplastic starch increased by the incorporation of the crosslinked starch/chitosan microparticles by melt-mixing. Toughness increased 360% in relation to unfilled thermoplastic starch. [ABSTRACT FROM AUTHOR]

The development of effective dual-function energy harvesting/storage technologies is a milestone demand for the emerging generation of low-consumption autonomous electronics. This work reports the development of a multifunctional thermionic power textile device merging thermal energy harvesting and electrochemical energy storage for application in self-powered systems. An everyday cost-effective non-conductive natural fabric was transformed into an all-solid-state textile-based thermally-chargeable supercapacitor (T-TCSC) via dyeing with multiwalled carbon nanotubes and subsequent assembly with H 3 PO 4 -doped poly(vinyl alcohol) (PVA) solid-gel polyelectrolyte. When subjected to an out-of-plane temperature gradient, the T-TCSC was able to convert the thermal energy into electrical output and store the harvested energy. A Soret coefficient of 1.85 mV K−1 was obtained, which is the highest value achieved so far for TCSCs developed on non-conductive textile substrates reported in literature and ∼10× higher than those of conventional thermoelectric devices. Additionally, a maximum output potential of ∼30 mV was achieved for Δ T = 24.7 K. Concerning the energy storage performance, an energy density of 9.39 μW h cm−2 was obtained at 1.62 mW cm−2 power density. The smart T-TCSC outputs demonstrated its potentialities as a two-in-one self-chargeable textile device that can harvest the thermal energy generated by a temperature gradient, convert it into electrical energy and simultaneously store it. [Display omitted] • Design and assembly of textile-based system merging energy generation and storage. • All-solid-state device produced on natural fabric through scalable dyeing/coating. • Simultaneous thermal-to-electrical energy conversion and supercapacitive storage. • A Soret coefficient S i = 1.85 mV K−1 and maximum V output = 30 mV@Δ T = ∼25 K were reached. • Highest S i reached so far for TCSCs produced on non-conductive textile substrates. [ABSTRACT FROM AUTHOR]

Gold nanoclusters (AuNCs) with fluorescence in the Near Infrared (NIR) by both one- and two-photon electronic excitation were incorporated in mesoporous silica nanoparticles (MSNs) using a novel one-pot synthesis procedure where the condensation polymerization of alkoxysilane monomers in the presence of the AuNCs and a surfactant produced hybrid MSNs of 49 nm diameter. This method was further developed to prepare 30 nm diameter nanocomposite particles with simultaneous NIR fluorescence and superparamagnetic properties, with a core composed of superparamagnetic manganese (II) ferrite nanoparticles (MnFe2O4) coated with a thin silica layer, and a shell of mesoporous silica decorated with AuNCs. The nanocomposite particles feature NIR-photoluminescence with 0.6% quantum yield and large Stokes shift (290 nm), and superparamagnetic response at 300 K, with a saturation magnetization of 13.4 emu g−1. The conjugation of NIR photoluminescence and superparamagnetic properties in the biocompatible nanocomposite has high potential for application in multimodal bioimaging. [ABSTRACT FROM AUTHOR]

Textile supercapacitors (TESCs) are an emerging energy storage solution to power smart gadgets integrated on clothes. Herein, efficient solid-state TESCs with different active areas (2–8 cm2) were produced based on cotton fabrics coated with industrial grade multi-walled carbon nanotubes (MWCNTs) as electrodes and a safe polyelectrolyte. The textile electrodes were fabricated by an optimized eco-friendly scalable dip-pad-dry process. The lowest electrical resistance (2.62 Ω cm−2) and most uniform coating of the electrodes were achieved using 10 mg mL−1 CNTs dispersion and 8 dip-pad-dry steps. The TESCs exhibited a specific capacitance of 8.01 F g−1 (9.18 F cm−2) and high cyclability (5000 cycles). The energy and power densities were tuned by changing the electrode area: the largest TESC presented the highest energy density of 6.30 Wh kg−1, which was 14× higher than those of other EDLC-type carbon-based TESCs reported in the literature; the smallest TESC presented the highest power density of 2.72 kW kg−1, being 49× higher than the values reported for comparable systems. Finally, a sensor was powered for 47 min by coupling two TESCs in series (14 cm2). This work demonstrated the ability to produce efficient TESCs using industrial grade MWCNTs by processes implemented in the Textile Industry, boosting technological transfer for high-tech applications. [ABSTRACT FROM AUTHOR]

Late diagnosis and systemic toxicity associated with conventional treatments make oncological therapy significantly difficult. In this context, nanomedicine emerges as a new approach in the prevention, diagnosis and treatment of cancer. In this work, pH-sensitive solid magnetoliposomes (SMLs) were developed for controlled release of the chemotherapeutic drug doxorubicin (DOX). Shape anisotropic magnetic nanoparticles of magnesium ferrite with partial substitution by calcium (Mg0.75Ca0.25Fe2O4) were synthesized, with and without calcination, and their structural, morphological and magnetic properties were investigated. Their superparamagnetic properties were evaluated and heating capabilities proven, either by exposure to an alternating magnetic field (AMF) (magnetic hyperthermia) or by irradiation with near-infrared (NIR) light (photothermia). The Mg0.75Ca0.25Fe2O4 calcined nanoparticles were selected to integrate the SMLs, surrounded by a lipid bilayer of DOPE:Ch:CHEMS (45:45:10). DOX was encapsulated in the nanosystems with an efficiency above 98%. DOX release assays showed a much more efficient release of the drug at pH = 5 compared to the release kinetics at physiological pH. By subjecting tumor cells to DOX-loaded SMLs, cell viability was significantly reduced, confirming that they can release the encapsulated drug. These results point to the development of efficient pH-sensitive nanocarriers, suitable for a synergistic action in cancer therapy with magnetic targeting, stimulus-controlled drug delivery and dual hyperthermia (magnetic and plasmonic) therapy. [ABSTRACT FROM AUTHOR]

Textile‐based shields are one of the most used solutions for electromagnetic interference (EMI) shielding in the radiofrequency range for several applications, such as personal protection, military, and aircraft. Herein, EMI textile shields are produced based on knitted cotton textile substrates (Jersey and American Fleece) coated with industrial‐grade multiwalled carbon nanotubes (MWCNTs) and graphene nanoplatelets (GNPs). An easy and scalable dip‐pad‐dry process is used to fabricate the textile‐based shields. The shielding effectiveness (SE) is evaluated over the frequency range of 5.85–18 GHz. The MWCNT‐coated American Fleece fabric presents the highest EMI shielding, with an average SE of ≈35.6 dB, which corresponds to an excellent classification for general use applications. Additionally, the electrical properties of the carbon nanomaterials and the thickness of the shields reveal to be correlated with an EMI shielding process mostly through radiation absorption mechanism. Numerical simulations are used to further assist in a thorough investigation regarding the influence of the electrical properties of the nanomaterials on the SE of the resulting coated fabrics. [ABSTRACT FROM AUTHOR]

Studies that aim to produce flexible films of composite materials based on ionomers-PZT, and volume fractions lower than 10% PZT, in order to monitor damage in aeronautical structures are seldom investigated. The growing emphasis on the use of polymers capable of self-healing after damage or activation by heating has motivated the application of self-healing ionomers as polymeric matrices in composites with piezoelectric particles aiming to monitor damage. Flexible composite films were developed based on the self-healing polymer matrix Surlyn® 8940 ionomer (DuPontTM—Wilmington, DE, USA) and PZT particles (connectivity 2–3) in volume fractions of 1, 3, 5 and 7%, with thickness around 50–100 µm. The choice of PZT volume fractions followed the preliminary requirement that establishes a final density, which is lower or at least close to the density of the materials used in aeronautical structures. Since the application of composites based on epoxy resin/carbon fibers has been increasing in the aeronautical segment, this material (with density lower than 1500 kg/m3) was chosen as a reference for the present work. Thus, due to self-healing (a characteristic of the matrix Surlyn® 8940) combined with recyclability, high flexibility and low thickness, the flexible composite films showed advantages to be applied on aeronautical structures, which present complex geometries and low-density materials. The manufactured films were characterized by SEM, XRD, DMA and mechanical tensile tests. The results were discussed mainly in terms of the volume fraction of PZT. X-ray diffraction patterns showed coexistent rhombohedral and tetragonal phases in the PZT particles-dispersed composite, which can potentialize the alignment of ferroelectric domains during polarization under strong electrical field, enhancing dielectric and piezoelectric properties toward sensing applications. DMA and tensile testing results demonstrated that the addition of PZT particles did not impair either dynamic or quasi-static mechanical performance of the flexible composite films. It was concluded that the PZT volume fraction should be lower than 3% because, for higher values, the molecular mobility of the polymer would suffer significant reductions. These findings, combined with the high flexibility and low density of the ceramic particle-filled thermoplastic polymer, render the developed flexible composite film a very promising candidate for strain and damage sensing in aeronautical structures. [ABSTRACT FROM AUTHOR]

To meet the basic requirements of long spans, steel footbridges are generally lightweight structures with low stiffness. Moreover, current trends in innovative structural design have led to more vibration problems related to resonance or quasi-resonance of footbridge structures at typical pedestrian walking frequencies. The present authors apply a feasible methodology to assess the vibration performance of footbridges based on an equivalent beam model developed from a detailed finite-element model and experimental measurements. Free- and induced-vibration tests are performed on a long-span inverted-queen-post-truss steel footbridge located in Rio de Janeiro, which exhibits vibration problems. Pedestrian walking simulations are performed with the simplified footbridge model using a typical dynamic load given from a Fourier series, as well as with a biodynamical formulation that considers human–structure interactions. The equivalent beam model provides a practical means of investigating corrective intervention strategies for the problem of excessive footbridge vibration using tuned mass dampers, and allows the in-service footbridge performance to be assessed based on current standards and design guidelines. [ABSTRACT FROM AUTHOR]

Human biomonitoring (HBM) data provide information on total exposure regardless of the route and sources of exposure. HBM studies have been applied to quantify human exposure to contaminants and environmental/occupational pollutants by determining the parent compounds, their metabolites or even their reaction products in biological matrices. HBM studies performed among the Portuguese population are disperse and limited. To overcome this knowledge gap, this review gathers, for the first time, the published Portuguese HBM information concerning polycyclic aromatic hydrocarbons (PAHs), metals, metalloids, and pesticides concentrations detected in the urine, serum, milk, hair, and nails of different groups of the Portuguese population. This integrative insight of available HBM data allows the analysis of the main determinants and patterns of exposure of the Portuguese population to these selected hazardous compounds, as well as assessment of the potential health risks. Identification of the main difficulties and challenges of HBM through analysis of the enrolled studies was also an aim. Ultimately, this study aimed to support national and European policies promoting human health and summarizes the most important outcomes and lessons learned through the HBM studies carried out in Portugal. [ABSTRACT FROM AUTHOR]

Human biomonitoring (HBM) data provide information on total exposure regardless of the route and sources of exposure. HBM studies have been applied to quantify human exposure to contaminants and environmental/occupational pollutants by means of determining the parent compounds, their metabolites, or even their reaction products in biological matrices. HBM studies performed among the Portuguese population are dispersed and limited. Thus, to overcome this knowledge gap, this work reviews the published Portuguese HBM information concerning mycotoxins detected in the urine, serum, milk, hair, and nails of different groups of the Portuguese population. This integrative approach to the available HBM data allows us to analyze the main determinants and patterns of exposure of the Portuguese population to the selected hazardous compounds, as well as to assess the potential health risks. We also aimed to identify the main difficulties and challenges of HBM through the analysis of the enrolled studies. Ultimately, this study aims to support national and European policies in promoting human health by summarizing the most important outcomes and lessons learned through the HBM studies carried out in Portugal. [ABSTRACT FROM AUTHOR]

The worldwide energy scarcity arising from the massive consumption of nonrenewable energy sources raised a global awareness of the need for cleaner and affordable energy solutions to mitigate climate change and ensure the world sustainable development. The rise of the Internet of Things and the fast growth of the groundbreaking market of wearable electronics boosted a major quest for self-powered technologies merging energy harvesting and energy storage functionalities to meet the demands of a myriad of market segments, such as healthcare, transportation, defense and sports. Thermoelectric devices are a green energy harvesting solution for wearable electronics since they harness the low-grade waste heat from ubiquitous thermal energy sources and convert it into electrical energy. However, these systems generate electrical energy in an intermittent manner, depend on the local heat release availability and require an additional unit to store energy. Flexible and wearable supercapacitors are a safe and eco-friendly energy storage solution to power wearables, offering advantages of security, longer cycle life, higher power density and faster charging over batteries. However, an additional unit that generates energy or that is able to charge the storage device is required. More recently, a new class of all-in-one thermally-chargeable supercapacitors blossomed to meet the requirements of the next generation of autonomous wearable electronics and ensure an endurable energy supply. This self-chargeable hybrid technology combines the functionalities of thermal energy harvesting and supercapacitive energy storage in a single multitasking device. In this Perspective, the advances in the burgeoning field of all-in-one thermally-chargeable supercapacitors for flexible/wearable applications will be critically examined, ranging from their structure and working principle to the rational design of the composing materials and of tailor-made architectures. It will start by introducing the foundations of single flexible/wearable thermoelectric generators and supercapacitors and will evolve into the pioneering venture of fully-integrated thermal energy harvesting/storage systems. It will end by highlighting the current bottlenecks and future pathways for advancing the development of this sophisticated smart technology. [ABSTRACT FROM AUTHOR]

A custom setup for Seebeck coefficient and electrical resistivity measurements of thin films as a function of temperature in the range of 10–300 K was developed. The Seebeck coefficient is measured using a two-probe arrangement and using either a dynamical or steady/quasi-steady differential method. The temperature differences (ΔTs) for these measurements across the samples are achieved by using resistive heaters embedded in two copper blocks. The sample is screwed to these blocks and is in pressured contact with the measurement probes. The electrical resistivity is measured with a two-probe arrangement. To verify the reliability of the developed setup, measurement tests were performed on commercial niobium foil and a specular spin valve previously studied, having obtained a great accordance (within ∼3%) between this setup's experimental results and the reference measurements. [ABSTRACT FROM AUTHOR]

Ochratoxin A (OTA) is produced by fungi present in several agricultural products with much relevance to food safety. Since this mycotoxin is widely found in cereals, beer has a potential contamination risk. Therefore, it was deemed essential to quantify, for the first time, the levels of OTA in beer, a cereal-based product that is marketed in Portugal, as well as to calculate the human estimated weekly intake (EWI) and risk assessment. A total of 85 samples were analyzed through immunoaffinity clean-up, followed by liquid chromatography-fluorescence detection (LC-FD). This analytical methodology allowed a limit of quantification (LOQ) of 0.43 µg/L. The results showed that 10.6% were contaminated at levels ranging between

Abstract Improved thermoelectric properties of p-Sb 2 Te 3 and n-Bi 2 Te 3 films deposited by thermal co-evaporation at 503 K and 543 K, respectively, are reported, by using two types of substrate (borosilicate glass and 25 μm - Kapton® polyimide). Seebeck coefficients of 194 μV K−1 and - 233 μV K−1 and electrical conductivities of 3.2 × 104 (Ω m)−1 and 5.0 × 104 (Ω m)−1, lead to optimized power factors of 1.2 × 10−3 W K−2 m−1 and 2.7 × 10−3 W K−2 m−1, measured at 298 K, for flexible Sb 2 Te 3 and Bi 2 Te 3 films, respectively. The power factor value increases until a maximum of 2.3 × 10−3 W m−1 K−2 for the p-type film, and to 5.9 × 10−3 W m−1 K−2 for the n-type film, at 373 K, respectively. An improvement of more than two times on the power factor value is observed when compared with the actual state-of-art for flexible Sb 2 Te 3 and Bi 2 Te 3 films, at room temperature, with thickness below 1 μm. A flexible thermopile sensor based on p - n films is presented, into possible thermal sensing. The thermoelectric device shows a responsivity of 0.05 V W−1 and a specific detectivity of 1.6 × 107 cm √Hz W−1. Highlights • Telluride films were fabricated on borosilicate glasses and Kapton® polyimide. • Power factors of 1.2 × 10−3 W K−2 m−1 (Sb 2 Te 3) and 2.7 × 10−3 W K−2 m−1 (Bi 2 Te 3). • Flexible thermopile sensor with a specific detectivity of 1.6 × 107 cm √Hz W−1. [ABSTRACT FROM AUTHOR]

A Ru supported on a magnetically separable chitosan-based nanomaterial (Mn@CS@Ru) was prepared by wet impregnation based on ionic gelation using sodium tripolyphosphate as a cross-linking agent. The ionic gelation of chitosan leads to a supporting matrix to promote the embedding of manganese(II) ferrite and Ru nanoparticles (NPs) by electrostatic interactions. The effects of the formulation and method parameters on the fabrication process were investigated, and the resulting as-prepared Mn@CS@Ru nanocatalyst was characterized. The catalytic activity of the Mn@CS@Ru nanomaterial was evaluated in the reduction of 4-nitrophenol (4-NP) and 4-nitroaniline (4-NA) in the presence of sodium borohydride as a reducing agent at room temperature. The turnover frequency values in the reduction of 4-NP and 4-NA were 273.9 and 336.5 min−1, respectively, which were attributed to the very small size of the hybrid nanomaterial (32.0±2.8 nm with 3.9±0.1 nm Ru NPs) that provided a large surface-area-to-volume ratio for the chemical reaction. Furthermore, the hybrid nanocatalyst was recovered easily by magnetic separation after the catalytic reaction and could be reused in at least 10 cycles without a loss of catalytic activity, which confirms its high stability. The present route is a new approach to synthesize highly active magnetic heterogeneous catalysts for the reduction of nitroarenes based on metallic NPs with easy accessibility, excellent activity, and convenient recovery. [ABSTRACT FROM AUTHOR]

In this report, a successful thermodynamical model was employed to understand the structural transition in Er5Si4, able to explain the decoupling of the magnetic and structural transition. This was achieved by DFT calculations, which were used to determine the energy differences at 0 K, using a LSDA+U approximation. It was found that the M structure is the stable phase at low temperatures, as verified experimentally with a value of ΔF0=-0.262 eV. Finally, a variation of Seebeck coefficient (~6 μV) was determined at the structural transition, which allows to conclude that the electronic entropy variation is negligible in the transition. [ABSTRACT FROM AUTHOR]

Nanoporous silica materials of regular porosity (of SBA-15 type) doped with magnetic iron oxide nanoparticles were prepared by two routes that differ essentially in the pH of the reaction medium and calcination step. Both routes produced magnetic SBA-15 materials with regular porosity and containing different loadings of iron oxide particles. The increase of the amount of iron oxide incorporated in SBA-15 was directly related with the increase of the pH during the material synthesis but the magnetic properties also showed a dependence on the type of calcination used. Two of the prepared materials showed relevant results for the catalytic degradation of acetaminophen, a pharmaceutical emerging pollutant. In the present work mild reaction conditions were used, that is, reaction conditions that do not involve imposition of low pH values, a specific radiation source nor high-pressure autoclave. [ABSTRACT FROM AUTHOR]

The development of stimuli-sensitive drug delivery systems is a very attractive area of current research in cancer therapy. The deep knowledge on the microenvironment of tumors has supported the progress of nanosystems' ability for controlled and local fusion as well as drug release. Temperature and pH are two of the most promising triggers in the development of sensitive formulations to improve the efficacy of anticancer agents. Herein, magnetic liposomes with fusogenic sensitivity to pH and temperature were developed aiming at dual cancer therapy (by chemotherapy and magnetic hyperthermia). Magnetic nanoparticles of mixed calcium/manganese ferrite were synthesized by co-precipitation with citrate and by sol–gel method, and characterized by X-ray diffraction (XRD), scanning electron microscopy in transmission mode (STEM), and superconducting quantum interference device (SQUID). The citrate-stabilized nanoparticles showed a small-sized population (around 8 nm, determined by XRD) and suitable magnetic properties, with a low coercivity and high saturation magnetization (~54 emu/g). The nanoparticles were incorporated into liposomes of dipalmitoylphosphatidylcholine/cholesteryl hemisuccinate (DPPC:CHEMS) and of the same components with a PEGylated lipid (DPPC:CHEMS:DSPE-PEG), resulting in magnetoliposomes with sizes around 100 nm. Dynamic light scattering (DLS) and electrophoretic light scattering (ELS) measurements were performed to investigate the pH-sensitivity of the magnetoliposomes' fusogenic ability. Two new antitumor thienopyridine derivatives were efficiently encapsulated in the magnetic liposomes and the drug delivery capability of the loaded nanosystems was evaluated, under different pH and temperature conditions. [ABSTRACT FROM AUTHOR]

Liposome-like nanoarchitectures containing manganese ferrite nanoparticles covered or decorated with gold were developed for application in dual cancer therapy, combining chemotherapy and photothermia. The magnetic/plasmonic nanoparticles were characterized using XRD, UV/Visible absorption, HR-TEM, and SQUID, exhibiting superparamagnetic behavior at room temperature. The average size of the gold-decorated nanoparticles was 26.7 nm for MnFe2O4 with 5–7 nm gold nanospheres. The average size of the core/shell nanoparticles was 28.8 nm for the magnetic core and around 4 nm for the gold shell. Two new potential antitumor fluorescent drugs, tricyclic lactones derivatives of thienopyridine, were loaded in these nanosystems with very high encapsulation efficiencies (higher than 98%). Assays in human tumor cell lines demonstrate that the nanocarriers do not release the antitumor compounds in the absence of irradiation. Moreover, the nanosystems do not cause any effect on the growth of primary (non-tumor) cells (with or without irradiation). The drug-loaded systems containing the core/shell magnetic/plasmonic nanoparticles efficiently inhibit the growth of tumor cells when irradiated with red light, making them suitable for a triggered release promoted by irradiation. [ABSTRACT FROM AUTHOR]

The implementation of processed magnetic materials onto thermoplastics can be an approach for practical use of brittle intermetallic materials on device development with the advantage of enlarging the range of applications. In this paper, we present the evaluation on the effect of blending magnetocaloric Gd 5 Si 2.4 Ge 1.6 3.4 μm particles with in different weight fractions onto a flexible, transparent and non-magnetic poly(methyl methacrylate) (PMMA). A close to homogeneous grain distribution along the polymer surface were achieved by using a simple solvent casting method for their magnetocaloric properties studies. From XRD analysis, it was found a unit cell volume shrinkage by increasing the powder concentration followed by a reduction on the amount of secondary monoclinic phase as a result of interfacial interactions. As a consequence, a weakening of secondary phases effect on the composite magnetocaloric behavior is observed as a result of the effective hydrostatic pressure from the difference between thermal expansions of matrix and filler. Unlabelled Image • Particle size reduction of Gd 5 Si 2.4 Ge 1.6 bulk to 3.4 μm increases the detection on the amount of distorted monoclinic phase. • The solvent casting technique allows a close to homogeneous dispersion of the micropowder along the composite volume. • Inclusion of the micropowder into the thermoplastic converts the monoclinic phase into an orthorhombic-I phase. • PMMA matrix works as a pressure cell for the micropowder leading to a reduction on the magnetocaloric response of the monoclinic phase. [ABSTRACT FROM AUTHOR]

Multifunctional liposomes containing manganese ferrite/gold core/shell nanoparticles were developed. These magnetic/plasmonic nanoparticles were covered by a lipid bilayer or entrapped in liposomes, which form solid or aqueous magnetoliposomes as nanocarriers for simultaneous chemotherapy and phototherapy. The core/shell nanoparticles were characterized by UV/Visible absorption, X-Ray Diffraction (XRD), Transmission Electron Microscopy (TEM), and Superconducting Quantum Interference Device (SQUID). The magnetoliposomes were characterized by Dynamic Light Scattering (DLS) and TEM. Fluorescence-based techniques (FRET, steady-state emission, and anisotropy) investigated the incorporation of a potential anti-tumor drug (a thienopyridine derivative) in these nanosystems. The core/shell nanoparticles exhibit sizes of 25 ± 2 nm (from TEM), a plasmonic absorption band (λmax = 550 nm), and keep magnetic character. XRD measurements allowed for the estimation of 13.3 nm diameter for manganese ferrite core and 11.7 nm due to the gold shell. Aqueous magnetoliposomes, with hydrodynamic diameters of 152 ± 18 nm, interact with model membranes by fusion and are able to transport the anti-tumor compound in the lipid membrane, with a high encapsulation efficiency (EE(%) = 98.4 ± 0.8). Solid magnetoliposomes exhibit hydrodynamic diameters around 140 nm and also carry successfully the anticancer drug (with EE (%) = 91.2 ± 5.2), while also being promising as agents for phototherapy. The developed multifunctional liposomes can be promising as therapeutic agents for combined chemo/phototherapy. [ABSTRACT FROM AUTHOR]

A study on the fundamental properties of Gd5−xLaxSi1.8Ge2.2 pseudo‐binary compounds with x = 1, 2, 3, 4, and 5 is performed by means of X‐ray powder diffraction (XRD) and magnetic measurements. An evolution from a monoclinic (M) Gd5Si2Ge2‐type to a tetragonal (T) Zr5Si4‐type structure, with the addition of La, is observed, finding that the T phase is stable for x ≥ 2. A monotonic expansion of the unit cell volume with a rate of 28 Å3/La by increasing the content of the non‐magnetic La ions in the system influences significantly the overall magnetic behavior. For instance, TC decreases in a rate of dTC/dx = −47.8 K La−1; and a considerable hysteresis reduction is observed as a result of the change on the nature of the phase transition from a first to a second‐order one. Hence, these results reveal the impact of a non‐magnetic La substitution on both magnetic and crystallographic properties of this series. A study on the crystallographic, magnetic, and magnetocaloric properties of (Gd,La)5(Si,Ge)4 pseudo‐binary compounds is presented here. The change from a monoclinic to a tetragonal structure for La content higher than 20% is observed. There is a monotonic decrease in TC with a considerable hysteresis reduction and a change on the nature of the phase transition from a first to a second‐order one. [ABSTRACT FROM AUTHOR]