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Articles publicats en revistes (Enginyeria Electrònica i Biomèdica)

URI permanent per a aquesta col·leccióhttps://hdl.handle.net/2445/7522

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    Peptide-Functionalized Silicon-Photonic E‑Nose for Monitoring Oxidation in Extra Virgin Olive Oil
    (American Chemical Society, 2026-03-24) Karami, Hamed; Pardo Martínez, Antonio; Fernández Romero, Luis; Rawal, Kaushal; Marco Colás, Santiago
    Oxidation is a major factor affecting the quality and shelf life of Extra Virgin Olive Oil (EVOO), leading to chemical degradation and loss of freshness. This study investigates the assessment of EVOO freshness using a peptide-based optoelectronic nose (OE-nose) system combined with signal processing and machine learning techniques. Volatile organic compound (VOC) profiles from fresh and oxidized EVOO samples were acquired using a multigas sensor array implemented on the Aryballe NeOse Advance platform. The oxidation status of the samples was validated using reference chemical quality analyses. Sensor signals were subjected to baseline correction and normalization, without the application of digital smoothing. Full-sequence analysis was employed to exploit desorption-phase kinetics as a volatility-driven, implicit preseparation mechanism, enabling robust discrimination without chromatographic steps. Exploratory and supervised models were evaluated, including principal component analysis (PCA), partial least-squares discriminant analysis (PLS-DA), and support vector machines (SVM). The SVM model achieved a classification accuracy of 100%, while PLS-DA reached 95.8% accuracy under strict validation conditions. Compared to conventional analytical methods, the proposed approach offers a rapid, nondestructive, and cost-effective solution for on-site EVOO freshness evaluation. To the authors’ knowledge, this work represents the first application of a peptide-based optoelectronic nose for assessing EVOO oxidation, highlighting its potential advantages over conventional MOX- and polymer-based electronic nose systems reported in previous studies.
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    Ultrathin Wide-Bandgap a-Si:H-Based Solar Cells for Transparent Photovoltaic Applications
    (Wiley-VCH, 2021-11-20) López García, Alex; Blazquez, Oriol; Voz Sánchez, Cristóbal; Puigdollers i González, Joaquim; Izquierdo‐Roca, Victor; Pérez Rodríguez, Alejandro
    Herein, the fabrication of UV-blue selective transparent solar cells based on ultrathin (<30 nm) intrinsic hydrogenated amorphous silicon films (a-Si:H) as absorber and using a fully inorganic architecture is reported, using metal-oxide thin films as carrier selective contacts and as transparent electrical contacts. These transparent ultrathin devices present a photovoltaic effect and high average visible transmittance (AVT), showing their potential as candidates for implementation as a transparent energy harvester. Potential applications range from Building-Integrated PV to agrophotovoltaics, and can also be of interest as a ubiquitous and inexpensive power source integrated in functional devices such as low-power devices, Internet of Things devices, and other sensors. Glass/FTO/ZnO/a-Si:H/MoO3/ITO device prototypes are produced. These devices present an AVT ranging from 50% to 69%, present a photovoltaic effect with a power conversion efficiency up to 0.5% calculated for an AM1.5G spectrum and have light utilization efficiency (LUE) values of 0.25%, confirming the potential of the proposed device architectures for the development of highly transparent devices with improved LUE.
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    SiC-Based MIS gas sensor for high water vapor environments
    (Elsevier, 2011) Casals Guillén, Olga; Becker, Th.; Godignon, P.; Romano Rodríguez, Albert
    In this work we will prove that SiC-based MIS capacitors can work in environments with extremely high concentrations of water vapor and still be sensitive to hydrogen, CO and hydrocarbons, making these devices suitable for monitoring the exhaust gases of hydrogen or hydrocarbons based fuel cells. Under the harshest conditions (45% of water vapor by volume ratio to nitrogen), Pt/TaOx/SiO2/SiC MIS capacitors are able to detect the presence of 1 ppm of hydrogen, 2 ppm of CO, 100 ppm of ethane or 20 ppm of ethene, concentrations that are far below the legal permissible exposure limits.
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    An LED Platform for Micropower Gas Sensors
    (MDPI, 2018-11-30) Markiewicz, Nicolai; Casals Guillén, Olga; Fàbrega Gallego, Cristian; Wasisto, Hutomo Suryo; Waag, Andreas; Prades García, Juan Daniel
    We developed an integrated platform to build up conductometric sensors with controlled illumination. Our device contains a miniaturized indium gallium nitride (InGaN) LED as a light source, and a set of interdigitated electrodes (IDEs) in close contact with the LED. The sensor material is later deposited on top of the IDE, to monitor its resistance. In this configuration, all the light emitted by the LED is collected by the sensor material, leading to a very efficient photoexcitation. We demonstrate the effectiveness of the approach building a photoactivated gas sensor based on ZnO operating with as little as 100 μW.
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    Cross-fertilization of knowledge and technologies in collaborative research projects
    (Emerald Publishing, 2021-03-22) González-Piñero, Manel; Páez Avilés, Cristina; Juanola, Esteve; Samitier i Martí, Josep
    This paper aims to explore how the cross-fertilization of knowledge and technologies in EU-funded research projects, including serious games and gamification, is influenced by the following variables: multidisciplinarity, knowledge base and organizations (number and diversity). The interrelation of actors and projects form a network of innovation. The largest contribution to cross-fertilization comes from the multidisciplinary nature of projects and the previous knowledge and technology of actors. The analysis draws on the understanding of how consortia perform as an innovation network, what their outcomes are and what capabilities are needed to reap value.
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    Visible Light Activated Room Temperature Gas Sensors Based on CaFe 2 O 4  Nanopowders
    (MDPI, 2018-12-07) Qomaruddin; Fàbrega Gallego, Cristian; Waag, Andreas; Šutka, A.; Casals Guillén, Olga; Wasisto, Hutomo Suryo; Prades García, Juan Daniel
    Gas sensors based on CaFe2O4 nanopowders, which are p–type metal oxide semiconductor (MOX), have been fabricated and assessed for ethanol gas monitoring under visible light activation at room temperature. Regardless of their inferior sensitivity compared to thermally activated counterparts, the developed sensors have shown responsive sensing behavior towards ethanol vapors confirming the ability of using visible light for sensor activation. LEDs with different wavelengths (i.e., 465–590 nm) were employed. The highest sensitivity (3.7%) was reached using green LED activation that corresponds to the band gap of CaFe2O4..
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    Association of Breathing Effort With Survival in Patients With Acute Respiratory Distress Syndrome
    (Lippincott, Williams & Wilkins, 2025-10) Parrilla-Gómez, Francisco José; Castellví, Andrea; Boutonnet, Víctor; Parrilla-Gómez, Andrés; Antolín Terreros, Marta; Mestre Somoza, Cristina; Blanes Bravo, Marina; Pratsobrerroca de la Rubia, Paola; Martín-López, Eva; Marco Colás, Santiago; Festa, Olimpia; Brochard, Laurent; Goligher, Ewan; Masclans Enviz, Joan Ramon
    OBJECTIVES: Invasive mechanical ventilation (IMV) is crucial for acute respiratory distress syndrome (ARDS) management, but mortality remains high. While spontaneous breathing is key to weaning, excessive respiratory effort may injure the lung and diaphragm. Most existing data on respiratory effort during IMV are based on brief periods of observation, potentially underestimating the burden of inappropriate efforts. This study aims to characterize the evolution of respiratory effort over time in ARDS patients and its relation to survival. We hypothesized that nonsurvivors would spend a greater proportion of time in the high-effort range during the active breathing phase compared with survivors. DESIGN, SETTING, AND PATIENTS: In this prospective cohort study, we continuously recorded airway pressure, flow, esophageal, and gastric pressures in ARDS patients on mechanical ventilation during 7 days after the onset of spontaneous breathing. We analyzed physiologic respiratory effort variables, focusing on the proportion of time spent within defined effort ranges, and compared these data between ICU survivors and nonsurvivors. Statistical analysis was conducted using variance weighted methods to account for variability in the number of respiratory cycles analyzed per patient. This study is registered at ClinicalTrials.gov under identifier NCT06490523. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: A total of 1,485,405 respiratory cycles were analyzed from 26 ARDS patients (19 survivors, seven nonsurvivors). Nonsurvivors spent significantly more time in high effort (12% vs. 3%; p = 0.006). In contrast, survivors spent more time in the moderate-effort range (50% vs. 5%; p < 0.001). The time spend with high dynamic transpulmonary driving pressure (> 25 cm H2O) was also significantly different between groups (32% survivors vs. 74% nonsurvivors; p = 0.001). CONCLUSIONS: Patients who die of ARDS are more likely to be exposed to high respiratory effort for prolonged periods of time compared with survivors.
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    Characterization and release modelling in ELR-based nanocomposite hydrogel loaded with polylactic acid for the implementation of a biomedical device
    (Elsevier B.V., 2025-08-05) Fernández-Fernández, Julio; Quintanilla-Sierra, Luis; Castaño Linares, Óscar; Roncada, Tosca; Rodríguez-Cabello, J. Carlos; Alonso, Matilde; Engel, Elisabeth; Santos, Mercedes
    Cardiac tissues are difficult to regenerate due to the low proliferative capacity of cardiomyocytes. A new therapeutic strategy for cardiac regenerative medicine could include a device capable of ensuring cell grafting, stimulating cardiac tissue regeneration, and serving as an appropriate scaffold for the controlled and sustained release of lactate over time as an inducer of cardiomyocyte proliferation. An effective source of lactate could consist of the lactic acid polymer (PLA) itself, which generates free lactic acid during its degradation. In this work, we have developed a nanocomposite hydrogel for lactate release based on a biocompatible and biodegradable matrix formed by elastin-like recombinamers cross-linked via click chemistry. Polylactic acid particles were encapsulated in the matrix after these particles had been partially degraded to lactic acid through oxygen plasma treatment. In the first 48 h, an early and modulated release of free lactic acid from plasma-treated PLA degradation is observed, and over longer periods, a sustained release of lactic acid produced by the hydrolytic degradation of PLA under physiological conditions occurs. Lactate is available from the very beginning (“early release”), addressing the drawback of the slow degradation (by hydrolysis) of polylactic acid. Therefore, a biomedical device has been designed and implemented, formed by an ELR polymeric matrix as an analogue of cardiac tissue, acting as a device for early, controlled, and sustained lactate release, with dosing at concentrations similar to those previously studied as suitable for promoting cardiomyocyte proliferation, showing promise for its use in the regeneration of infarcted cardiac tissue.
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    Low-cost colorimetric sensor for ppb-level formaldehyde monitoring
    (Elsevier B.V., 2026-08-15) González Gómez, María; Zymohliad, Anna; Benito Altamirano, Ismael; Casals Guillén, Olga; Prades García, Juan Daniel; Fàbrega Gallego, Cristian
    Formaldehyde is a hazardous indoor pollutant, and low-cost sensors capable of monitoring exposures at partsper-billion (ppb) levels remain scarce. Here, we report a paper-based colorimetric sensor combining a primary amine/pH-indicator ink with an off-the-shelf LED/photodetector module for quantitative detection. Formaldehyde reacts with the amine to form an imine, inducing a localized pH shift and visible color change detected optically. Continuous reaction rate monitoring enables quantitative tracking of formaldehyde concentration. The ink formulation was optimized for sensitivity and saturation time (4.2% aPEG, 4% PEG), while adjustments in film thickness and substrate reflectivity allow performance tailoring for specific applications. Because relative humidity significantly modulates the sensor response through reversible imine hydrolysis, several calibration approaches, considering non-linear and linear dependence with humidity were evaluated. A multivariable linear regression model incorporating formaldehyde concentration, relative humidity, and their interaction term was</p><p>selected, explaining 94% of the variance in the sensor signal. After testing the model with simultaneous variations of all dependent variables (a deliberately aggressive validation scenario), a key insight emerged: the time evolution of the system must be incorporated in future models, as accumulated reaction products can introduce systematic deviations. The sensor selectively detected formaldehyde in the 80–600 ppb range with an experimental LoD of 80 ppb and negligible interference from NH₃, NO₂, EtOH, CO, and CO₂. Repeated exposures over seven days yielded 155.6 ± 14.3 ppb for 35 exposures at a nominal 160 ppb concentration (≈7% error). Sensor response was minimally affected by 25–40 ◦C, indicating no thermal compensation is required.
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    Ultra Low-Cost and Selective Water-Based Colorimetric Ink for Indoor CO2 Monitoring
    (Institute of Electrical and Electronics Engineers (IEEE), 2025-04-16) González Gómez, María; Benito Altamirano, Ismael; Prades García, Juan Daniel; Casals Guillén, Olga; Fàbrega Gallego, Cristian
    This work introduces a novel water-based colorimetric ink for CO2 monitoring, offering a significant advancement in indoor air quality assessment. The ink uses a highly specific and reversible reaction between CO2 and an amine, enabling precise detection within a broad operational range of 150–1500 ppm, encompassing typical indoor CO2 concentrations. Optimized rheological properties allow for seamless application on paper substrates, facilitating scalable production and widespread adoption. The resulting colorimetric labels exhibit exceptional resistance to common interfering gases, ensuring accurate and reliable CO2 readings even in challenging indoor environments with fluctuating humidity and temperature and potential crosscontamination. Rigorous characterization of the sensor showcases outstanding performance in terms of specificity, repeatability, and reproducibility, validating its robustness and suitability for real-world applications. To further enhance accuracy, a calibration methodology incorporating a signal compensation algorithm is proposed, effectively mitigating humidity-induced effects. The sensor response can be effortlessly captured using readily available and cost-effective electronic components, paving the way for an accessible and versatile solution for real-time CO2 monitoring in both residential and commercial settings. Moreover, the inherent versatility of this technology allows for integration with other colorimetric inks, opening doors to a multiparametric sensing platform capable of monitoring a wider array of indoor air quality pollutants.
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    Enhanced Selective Contact Behavior in a-Si:H/oxide Transparent Photovoltaic Devices via Dipole Layer Integration
    (Wiley-VCH, 2024-06-14) López García, Alex; Álvarez Suárez, Gustavo; Ros Rahola, Emilio; Ortega Villasclaras, Pablo Rafael; Voz Sánchez, Cristóbal; Puigdollers i González, Joaquim; Pérez Rodríguez, Alejandro
    Transparent photovoltaic (TPV) devices have the potential to revolutionize photovoltaic (PV) technology by enabling on-site generation while minimizing visual impact. However, a major challenge in the development of TPV, as well as for many PV technologies, is the open-circuit voltage (Voc) deficit, which limits their efficiency. In this work, the development of wide-bandgap inorganic-based TPV devices is reported with a focus on low-cost, earth-abundant, stable, and nontoxic materials. The device structure consists of an ultrathin hydrogenated amorphous silicon (a-Si:H) absorber and metal-oxide layers as selective contacts. Herein, novel approach is presented to significantly improve device performance, especially in Voc, by introducing molecular dipoles in the device electron transport layer. By incorporating polyethyleneimine or poly(amidoamine) G1 and G2 dipoles, Voc (from 410 mV up to 638 mV) is significantly increased without sacrificing the average photopic transmittance of the device, leading to a record efficiency for this particular approach in TPV. Measurements confirm excellent long-term stability. This approach can potentially allow tuning the work function of the selective contacts enabling the use of low-cost, earth-abundant materials that are not optimized for a particular absorber. Furthermore, this solution circumvents the issue of low Voc by a simple interface treatment.
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    Exploring the Limits and Balancing Efficiency, Transparency, and Esthetics in Ultrathin a-Si:H Transparent Photovoltaic Devices
    (Wiley-VCH, 2025-01-08) Álvarez Suárez, Gustavo; López García, Alex; Estarlich, Pau; Asensi López, José Miguel; Masmitjà, Gerard; Ortega, Pablo; Voz Sánchez, Cristóbal; Puigdollers i González, Joaquim; Pérez Rodríguez, Alejandro
    Transparent photovoltaic (TPV) devices represent a promising advance in photovoltaic technologies, particularly in building-integrated photovoltaics (BIPV). Unlike conventional photovoltaics, which primarily prioritize efficiency, TPV must balance between efficiency, transparency, and aesthetics. These additional dimensions introduce unique challenges on device architecture. This article reports the development of wide-bandgap, inorganic-based TPV devices integrating ultrathin hydrogenated amorphous silicon (a-Si:H) as a transparent absorber, with carrier selective contacts and transparent electrodes. The article analyzes how absorber thickness influences the electrical, optical, and aesthetic performance of devices, evaluating key parameters in TPV such as light utilization efficiency (LUE), average photopic transmittance (APT), color rendering index (CRI), and electrical properties such as power conversion efficiency (PCE). The device structure is SLG/FTO/AZO/a-SiCx(n)/ a-Si:H/V2Ox/AZO. This approach results in PCE ranging from 1.7% with an APT of 60% to a PCE of 4.1% with an APT of 28%, yielding LUE values between 0.9% and 1.3%. Device characterization encompasses optical spectrophotometry, J–V measurements under standard test conditions, spectral response analysis, and variable illumination measurements (VIM). Additionally, color characterization is conducted using CIE 1931 color space maps to determine the chromaticity coordinates, CRI, and the variation of color as a function of absorber thickness.
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    Heparin binding induced supramolecular chirality into the self-assembly of perylenediimide bolaamphiphile
    (Royal Society of Chemistry, 2024-07-02) Sharma, Poonam; Venugopal, Akhil; Martínez Verdi, Claudia; Serra Roger, Mauri; Calò, Annalisa; Kumar, Mohit
    Chirality is one of the hallmarks of biomolecules. Herein, we utilize heparin, a chiral biomolecule and potent drug, to induce chiral organization into the assembly of an achiral molecule. Polyanionic heparin binds with a dicationic perylenediimide derivative to induce supramolecular helical organization in aqueous medium as well as in a highly competitive cell culture medium.
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    Long-Distance Charge Transport between Cytochrome c and Complex III is Mediated by Protons and Reactive Oxygen Species
    (Wiley-VCH, 2025-09-12) Lagunas, Anna; Gomila, Alexandre M. J.; Nin Hill, Alba; Guerra-Castellano, Alejandra; Pérez-Mejías, Gonzalo; Samitier i Martí, Josep; Rovira i Virgili, Carme; Rosa, Miguel A. de la; Díaz Moreno, Irene; Gorostiza Langa, Pablo Ignacio
    Electron transfer (ET) between redox proteins is an essential process in the respiratory and photosynthetic transport chains. While intra-protein ET is well characterized, the experimental methods to investigate inter-protein ET are limited by the presence of the solvent and by the transient nature of the protein– protein interaction and ET event, which are averaged in protein ensembles. Wiring precisely oriented redox protein partners to the nanoscale electrodes of an electrochemical scanning tunneling microscope allows recording the time- and distance-dependence of the current flowing between them. These methods have revealed that the current flowing between individual protein pairs extends beyond tunneling distances and that it is electrochemically gated. However, the corresponding mechanism and the identity of the charge carriers in aqueous solution remain to be elucidated. To determine the species involved in long-distance charge transport between the redox partner proteins Cc and Cc1 of the respiratory chain, recordings are performed as a function of pH, in heavy water solutions, and in degassed solutions. It is observed that the spatial span and electrochemical gating of long-distance currents are reduced at high pH, in heavy water, and at low oxygen concentration, showing that the currents are assisted by superoxide anions and by protons.
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    Strong Cavity-Optomechanical Transduction of Nanopillar Motion
    (American Chemical Society, 2024-08-21) Jaramillo Fernández, Juliana; Poblet, Martin; Alonso Tomás, David; Bertelsen, Christian Vinther; López Aymerich, Elena; Arenas Ortega, Daniel; Svendsen, Winnie Edith; Capuj, Néstor E.; Romano Rodríguez, Albert; Navarro Urrios, Daniel
    Nanomechanical resonators can serve as ultrasensitive,miniaturized force probes. While vertical structures such as nanopillarsare ideal for this purpose, transducing their motion is challenging. Pillar-based photonic crystals (PhCs) offer a potential solution by integratingoptical transduction within the pillars. However, achieving high-qualityPhCs is hindered by inefficient vertical light confinement. Here, wepresent a full-silicon photonic crystal cavity based on nanopillars as aplatform for applications in force sensing and biosensing areas. Its unit cellconsists of a silicon pillar with a larger diameter at its top portion than atthe bottom, which allows vertical light confinement and an energy bandgap in the near-infrared range for transverse-magnetic polarization. Weexperimentally demonstrate optical cavities with Q factors exceeding 1e3,constructed by inserting a defect within a periodic arrangement of thistype of pillars. Each nanopillar naturally behaves as a nanomechanicalcantilever, making the fabricated geometries excellent optomechanical (OM) photonic crystal cavities in which the mechanicalmotion of each nanopillar composing the cavity can be optically transduced. These geometries display enhanced mechanicalproperties, cost-effectiveness, integration possibilities, and scalability. They also present an alternative in front of the widelyused suspended Si beam OM cavities made on silicon-on-insulator substrates.
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    Comparison of magnetic data products from Solar Orbiter SO/PHI-FDT and SDO/HMI
    (EDP Sciences, 2024-04-30) Moreno Vacas, A.; Orozco Suárez, D.; Strecker, H.; Toro Iniesta, J.C. del; Borrero, J.M.; Albert, K.; Solanki, S.K.; Bailén, F.J.; Bellot Rubio, L.R.; Hirzberger, J.; Sinjan, J.; Santamarina Guerrero, P.; Valori, G.; Albelo Jorge, N.; Alvarez-Herrero, A.; Appourchaux, T.; Blanco Rodríguez, J.; Calchetti, D.; Feller, A.; Fiethe, B.; Gandorfer, A.; Germerott, D.; Gizon, L.; Gómez Cama, José María; Guerrero, L.; Gutierrez-Marques, P.; Kahil, F.; Kolleck, M.; Korpi-Lagg, A.; Michalik, H.; Pérez-Grande, I.; Sanchis Kilders, E.; Schou, J.; Schühle, U.; Staub, J.; Volkmer, R.; Woch, J.
    Context. The Polarimetric and Helioseismic Imager (SO/PHI), on board the Solar Orbiter mission, is the first photospheric magnetograph and tachograph to observe the Sun from outside the Sun-Earth line. The Full Disc Telescope (FDT) of SO/PHI, images the whole solar disk with a spatial resolution that varies with the distance between the Sun and the spacecraft.Aims. We check for consistency between the magnetic field strength (B), the field inclination (γ), the line-of-sight (LoS) magnetic component (BLoS) and the field azimuth (φ), inferred by SO/PHI-FDT and the Helioseismic and Magnetic Imager (HMI), on board Solar Dynamics Observatory (SDO), and obtain linear correlation coefficients among them.Methods. We use data from both instruments obtained on 8 March 2022, when the angle between SDO and Solar Orbiter was 3.4◦ and the solar disk showed four developed active regions. Before comparing the magnetic field products of both instruments we perform a precise alignment of the data, including a matching of the plate scale. Further, in order to improve the homogeneity of the compared data products, the SDO/HMI data were convolved with the SO/PHI-FDT point spread function (PSF). The linear correlation coefficients are obtained through a linear regression of SDO/HMI to SO/PHI-FDT.Results. The two instruments yield comparable magnetic field data products. The slope coefficients for a linear fit are 1.37 for B, 1.11 for γ, 1.35 for BLoS and 1 for the azimuth. The corresponding fit offsets are−94 G,−9.8◦, 5.2 G and 0.1◦, respectively. The agreement between both instruments is significantly better when we take into account the different spatial resolution of both instruments. The fitting results vary slightly depending on the analyzed active region except for one of the four active regions, which shows larger differences and has been excluded from the comparison. The comparison of the LoS magnetic field products from SDO/HMI at 45 s and 720 s with SO/PHI-FDT shows a slope value of 1.17, with the offset less than 6 G, in both cases.
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    Optimizing Instrumental Odour Monitoring Systems in Drones by Feature Selection for Odour Detection and Odour Concentration Estimation
    (Elsevier B.V., 2026-04-01) Benegiamo, Alessandro; Alonso Valdesueiro, Javier; Burgués, Javier; Vidal, Albert; Saúco, Lidia; Esclapez, María Deseada; Doñate, Silvia; Gutiérrez Gálvez, Agustín; Marco Colás, Santiago
    Fugitive odour emissions from wastewater treatment plants (WWTPs) present ongoing analytical and environmental challenges. Drone-mounted Instrumental Odour Monitoring Systems (IOMS) enable real-time, spatially resolved chemical sensing; however, large sensor arrays increase calibration complexity and cost. To address this, IOMS optimization is formulated as a machine-learning feature-selection problem. A two-stage selection strategy is introduced, combining Sequential Forward Selection (SFS) and Interval Partial Least Squares (iPLS) regression to identify minimal, information-rich sensor subsets and optimal temporal measurement windows. The approach is evaluated using data from a hexacopter-borne IOMS equipped with 21 sensors operating over an active WWTP. Sensors are ranked according to their incremental contribution to odour-concentration prediction error reduction, followed by refinement of measurement intervals to capture relevant temporal dynamics. Validation on independent flight data demonstrates that a configuration comprising only three sensors with optimized time windows retains or improves predictive performance relative to the full array. For quantification, the Bland–Altman limits of agreement improve from ±7 to ±5.3 dBod, and the Pearson correlation increases from 0.80 to 0.89. For odour-detection task, a single sensor achieves an AUC of 0.95, slightly outperforming the full sensor set (AUC = 0.93). Bootstrap analysis reveals variability in feature selection, though consistent trends are observed: ammonia sensors dominate quantitative models, whereas low-temperature MOX sensors are preferred in detection. The findings demonstrate the effectiveness of feature-selection strategies in simplifying IOMS hardware while preserving chemometric performance.
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    Experimental radar absorption in high-filling factor magnetic composites
    (Elsevier B.V., 2025-01-01) Calvo de la Rosa, Jaume; Vazquez-Aige, Marc; Medina, Laura; Marín, Pilar.; López Villegas, José María; Tejada, Javier; Pérez, Paula
    The electromagnetic properties and microwave absorption capabilities of mono- and bilayer composite samples, comprising a polymeric matrix and a magnetic powder filler (either metallic or ceramic), are evaluated in an anechoic chamber under realistic radar conditions. The study examines the influence of the filler type and the filling factor on performance. The findings reveal exceptional broadband microwave absorption, positioning these materials as prime candidates for stealth technology applications. Experimentally, absorption levels reach up to −40 dB, while predictive modeling indicates the potential to surpass −50 dB. The experimental results align closely with model predictions for both single-layer and bilayer systems, underscoring their reliability and effectiveness.
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    An internet of things-based intensity and time-resolved fluorescence reader for point-of-care testing
    (Elsevier B.V., 2020-04-15) Alonso Casanovas, Oscar; Franch Masdeu, Nil; Canals Gil, Joan; Arias Alpízar, Kevin; de la Serna, Erica; Baldrich, E.; Diéguez Barrientos, Àngel
    A miniature internet of things (IoT)-based point-of-care testing (PoCT) fluorescence reader, able to perform both intensity and time-resolved measurements of different fluorescent tags, is presented. This low cost platform has been conceived for performing tests in low-resource and remote settings, displaying versatile performance and yet simple operation. It consists on an external case of 43 × 30 × 42 mm3 (built in a 3D-printer) where all the elements are fixed, including some basic optics (3 lenses and 2 filters), a laser diode and a custom designed Single-Photon Avalanche Diodes (SPADs) camera. Both, the laser and the camera are controlled by a Field Programmable Gate Array (FPGA) with IoT capabilities. The PoCT was validated by detecting Plasmodium antigen in a fluorescent enzyme-linked immunosorbent assay (ELISA) using a fluorescence substrate. The results were compared to those provided in parallel by two commercial fluorescent plate readers. As it will be shown, the PoCT fluorescent readout was more sensitive than its colorimetric counterpart. Furthermore, the PoCT displayed similar signal trends and levels of detection than the bulkier and more expensive commercial fluorescence plate readers. These results demonstrate that the PoCT platform developed could bring the performance of central laboratory assay techniques closer to the end-user level.
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    Structure and mechanistic basis of NrdR, a bacterial master regulator of ribonucleotide reduction
    (Elsevier B.V., 2026-02-04) Pedraz López, Lucas; Szura, Arkadiusz; Schmitz, Claus; Rubio Canalejas, Alba; Martínez Mateos, Ángela; Santella, Anthony; Gomila Lluch, Gabriel; Calò, Annalisa; Solà, Maria; Torrents Serra, Eduard
    Ribonucleotide reductases (RNRs) are the essential enzymes responsible for synthesizing dNTPs, the building blocks of DNA. In bacteria, the entire RNR network is controlled by the master regulator NrdR. As a regulator of an essential pathway with no eukaryotic equivalent, NrdR is a promising antimicrobial target. Recent structural studies have outlined a mechanism of action for NrdR, in which ATP and dATP induce changes in the protein quaternary structure, regulating RNR repression. However, due to a lack of functional studies linking the known structures to their biological roles, the activation mechanism of NrdR is not yet fully understood. Here, we conducted a comprehensive study of NrdR in Escherichia coli and Pseudomonas aeruginosa. We delimited the NrdR regulon, combining transcriptomics and motif-based sequence analysis. We crystallized E. coli NrdR and identified the protein-protein interfaces involved in its oligomerization, including strong interactions between NrdR dimers to form tetramers, and less stable interfaces connecting such tetramers. We examined the variability of the quaternary structures of NrdR depending on the bound nucleotides by SEC-MALS and atomic force microscopy, and correlated structure to function using point mutations, EMSAs, and in vitro transcription assays. Overall, our results demonstrate the mechanism used by NrdR to modulate its quaternary structure and activity, deciphering essential interactions between subunits, and paving the way for targeted antimicrobial therapies.