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3D-Printed SARS-CoV-2 RNA Genosensing Microfluidic System
(Wiley, 2022-02-05) González Crevillén, Agustín; Mayorga-Martinez, Carmen C.; Vaghasiya, Jayraj V.; Martin Pumera
Additive manufacturing technology, referred as 3D printing technology, is a growing research field with broad applications from nanosensors fabrication to 3D printing of buildings. Nowadays, the world is dealing with a pandemic and requires the use of simple sensing systems. Here, the strengths of fast screening by a lab-on-a-chip device through electrochemical detection using 3D printing technology for SARS-CoV-2 sensing are combined. This system comprises a PDMS microfluidic channel integrated with an electrochemical cell fully 3D-printed by a 3D printing pen (3D-PP). The 3D-PP genosensor is modified with an ssDNA probe that targeted the N gene sequence of SARS-CoV-2. The sensing mechanism relies on the electro-oxidation of adenines present in ssDNA when in contact with SARS-CoV-2 RNA. The hybridization between ssDNA and target RNA takes a place and ssDNA is desorbed from the genosensor surface, causing a decrease of the sensor signal. The developed SARS-CoV-2/3D-PP genosensor shows high sensitivity and fast response.
3D-printed Transmembrane Glycoprotein Cancer Biomarker Aptasensor
(Elsevier, 2021-08-21) González Crevillén, Agustín; Mayorga Martinez, Carmen C.; Zelenka, Jaroslav; Rimpelová, Silvie; Ruml, Tomáš; Pumera, Martin
Point-of-care, easy to manufacture, and low cost detection of cancer biomarkers is crucial for fighting the early stage disease. 3D printing allows delocalized printing at remote locations with updates/upgrades available globally via electronic files. Mucin 1 (MUC1) is a protein that is overexpressed in a number of epithelial cancers and is a key factor in advancement of the disease. Here we show the simple point-of-care 3D printing fabrication of a MUC1 aptasensor using a nanocarbon/polymer filament. Efficacy of the 3D-printed aptasensor is demonstrated by monitoring the expression and release of MUC1 in breast cancer cell cultures. Such a simple, low cost, and easy to locally fabricate cancer biosensor will have a large impact on the field of cancer diagnostics.
Abelian Actions on Pseudo-real Riemann Surfaces
(Springer, 2023-04-08) Bujalance García, Emilio; Cirre Torres, Francisco Javier; J. Rodríguez
A compact Riemann surface is called pseudo-real if it admits orientation-reversing automorphisms but none of them has order two. In this paper, we find necessary and sufficient conditions for the existence of an action on a pseudo-real surface of genus g 2 of an abelian group containing orientation-reversing automorphisms. Several consequences are obtained, such as the solution of the minimum genus problem for such abelian actions.
Absorbing Markov decision processes
(EDP Sciences, 2024-02-09) Dufour, François; Prieto Rumeau, Tomás
In this paper, we study discrete-time absorbing Markov Decision Processes (MDP) with measurable state space and Borel action space with a given initial distribution. For such models, solutions to the characteristic equation that are not occupation measures may exist. Several necessary and sufficient conditions are provided to guarantee that any solution to the characteristic equation is an occupation measure. Under the so-called continuity-compactness conditions, we first show that a measure is precisely an occupation measure if and only if it satisfies the characteristic equation and an additional absolute continuity condition. Secondly, it is shown that the set of occupation measures is compact in the weak-strong topology if and only if the model is uniformly absorbing. Several examples are provided to illustrate our results.
Addition reaction of azoles to acetone-d 6: NMR and computational studies
(Wiley, 2024-05-22) Claramunt Vallespí, Rosa María; Sanz del Castillo, Dionisia; Alkorta, Ibon; Elguero, José
The reactivity of imidazole, pyrazole, 1,2,4-triazole, 1,2,3-triazole and tetrazole with acetone (propan-2-one) has been studied by 1 H and 13 C NMR using acetone-d 6 as solvent at temperatures ranging from 173 to 300 K at 10 K intervals. Simultaneously, the reaction has been theoretically calculated at the B3LYP/6-311++G(d,p) level and experimental and theoretical results compared. The equilibrium constants between azoles and adducts α,α-dimethyl-azole-methanol were analyzed assuming that the straight part of the plots –R ln Ke vs. 1/T can be used to determine ΔH and ΔS. Calculated and experimental data are related but the theoretical values are proportionally higher. The tautomerism of triazoles and tetrazole has been considered in order to discuss the reactions.
Analysis of smart thermostat thermal models for residential building
(Elsevier, 2022-06-02) Arias, J.; Khan, A.A.; Rodriguez Uría, J.; Sama Meige, Miguel Ángel
This work studies the thermal behavior of residential buildings by using the data provided by smart thermostats and weather forecast data. We consider an equivalent circuit model depending on four parameters related to the heater power, the solar energy, heat capacity, and the thermal resistance of the building. We employ a random ordinary differential equation to overcome the natural model uncertainty. We develop a differential equation constrained least-squares-based parameter identification approach for uncertainty quantification. We provide results related to the analytic properties of the parameter-to-solution map involving a derivative characterization. Furthermore, using a discretization scheme adapted to the given data, we derive discrete formulas for the deterministic identification model and compute the statistical moments of the random model. Following a machine learning approach, we propose an algorithm that consists of three phases. The first is a training phase where we identify the parameter uncertainties on a training dataset. In the second phase, we establish a normal distribution of the parameters using these uncertainties. In the final phase, we simulate the temperature on a test dataset by solving the random model. We test this algorithm on real data from two residential buildings. The detailed numerical experiments show the feasibility and the efficacy of the developed framework.
Analysis of total arsenic content in purchased rice from Ecuador
(Czech Academy of Agricultural Sciences, 2019-12-31) Atiaga Franco, Oliva L.; Otero, Xose L.; Gallego Picó, Alejandrina; Escobar Castañeda, Luis A.; Carrera Villacrés, David; Bravo Yagüe, Juan Carlos
Natural and anthropogenic sources contribute to arsenic contamination in water and human food chain in Andean countries. Human exposure to arsenic via rice consumption is of great concern in countries where this crop is the dominant staple food, and limited information is available on the arsenic contamination on rice in Ecuador. This work was to contribute to the lack of knowledge analysing total arsenic by hydride generation-atomic absorption spectrometry in the samples of white, brown and parboiled rice purchased in Ecuadorian markets and produced in the two main rice wetlands in Ecuador, Guayas and Los Ríos, were carried out. For the samples from Guayas, arsenic concentration in white, brown and parboiled rice were 0.174 ± 0.014, 0.232 ± 0.021, and 0.186 ± 0.017 mg/kg respectively, whereas samples of white rice from Los Ríos showed a total arsenic level of 0.258 ± 0.037 mg/kg. This last arsenic concentration exceeds recommended maximum permissible limit by the FAO/WHO. Obtained data have available to estimate the Ecuadorian dietary exposure revealing serious health risk for population
Asymptotically Linear Problems and Antimaximum Principle for the Square Root of the Laplacian
(2016-03-10) Arcoya, David; Colorado, Eduardo; Leonori, Tommaso; https://orcid.org/0000-0002-7284-2413; https://orcid.org/0000-0002-1067-5752; https://orcid.org/0000-0002-0848-4463
This work deals with bifurcation of positive solutions for some asymptotically linear problems, involving the square root of the Laplacian (-Delta)(1/2). A simplified model problem is the following: {(-Delta)(1/2)u = lambda m(x)u + g(u) in Omega, u = 0 on partial derivative Omega, with Omega subset of R-N a smooth bounded domain, N >= 2, lambda > 0, m is an element of L-infinity(Omega), m(+) not equivalent to 0 and g is a continuous function which is super-linear at 0 and sub-linear at infinity. As a consequence of our bifurcation theory approach we prove some existence and multiplicity results. Finally, we also show an anti-maximum principle in the corresponding functional setting.
Basic estimates for solutions of a class of nonlocal elliptic and parabolic equations
(American Institute of Mathematical Sciences (AIMS), 2015-12) Leonori, Tommaso; Peral, Ireneo; Primo, Ana; Soria, Fernando; https://orcid.org/0000-0002-0848-4463; https://orcid.org/0000-0003-2297-9910; https://orcid.org/0000-0003-1804-3175; https://orcid.org/0000-0001-5753-807X
In this work we consider the problems { script Lu = f in Ω, u = 0 in ℝN\Ω, and { ut + script Lu = f in QT ≡ Ω x (0,T), u(x,t) = 0 in (ℝN\Ω) x (0,T), u(x, 0) = 0 in Ω, where script L is a nonlocal differential operator and Ω is a bounded domain in ℝN, with Lipschitz boundary. The main goal of this work is to study existence, uniqueness and summability of the solution u with respect to the summability of the datum f. In the process we establish an Lp-theory, for p ≥ 1, associated to these problems and we prove some useful inequalities for the applications.
The best approximation of a given function in L2-norm by Lipschitz functions with gradient constraint
(De Gruyter, 2024-04-24) Buccheri, Stefano; Leonori, Tommaso; Rossi, Julio D.; https://orcid.org/0000-0002-0667-233X; https://orcid.org/0000-0002-0848-4463; https://orcid.org/0000-0002-5905-4412
Boundary conditions derived from a microscopic theory of hydrodynamics near solids
(American Institute of Physics, 2019-04-08) Camargo-Trillos, Diego; Torre, J. A. de la; Delgado Buscalioni, Rafael; Chejne, Farid; Español Garrigos, José
The theory of nonlocal isothermal hydrodynamics near a solid object derived microscopically in the study by Camargo et al. [J. Chem. Phys. 148, 064107 (2018)] is considered under the conditions that the flow fields are of macroscopic character. We show that in the limit of macroscopic flows, a simple pillbox argument implies that the reversible and irreversible forces that the solid exerts on the fluid can be represented in terms of boundary conditions. In this way, boundary conditions are derived from the underlying microscopic dynamics of the fluid-solid system. These boundary conditions are the impenetrability condition and the Navier slip boundary condition. The Green-Kubo transport coefficients associated with the irreversible forces that the solid exert on the fluid appear naturally in the slip length. The microscopic expression for the slip length thus obtained is shown to coincide with the one provided originally by Bocquet and Barrat [Phys. Rev. E 49, 3079 (1994)].
Changes in littoral dynamics and sea level in southern Iberia and Canary Istands during the Holocene.
(Sociedad Geológica de España, 1996) Zazo Cardeña, Caridad; Dabrio, Cristino José; Goy Goy, José Luis; Bardají Azcárate, Teresa; Ghaleb, B.; Lario Gómez, Javier
The interaction between global factors tglobal" glacio-eustatic sea-leve/ rise) and regional factors (tectonic trend, oceanographic factor) is analyzed in different areas of the lberian and Canary lsland littora/. Sea-leve/ changes and climatic variations are stated for the Mediterranean and Atlantic littora/s, with different tidal ranges and tectonic trends. Different stages can be envisaged in the coastal evolution of a/most ali the analyzed areas from the beginning of Holocene (10.000 BP): at ca. 7.000 BP (Flandrian maximum) with a change from open estuaries to aggradational processes (Cádiz Gulf, subsiding area), basal peat (Valencia Gulf, subsiding area) and development of microcliffs (Mediterranean uplifting areas). From 7,000 to 2,700 BP a first progradation phase with development of spit bars took place in the mediterranean uplifting areas, whilst in the atlantic subsiding one starts the aggradation processes in the formerly open estuaries, an a/so from ca.4,000 BP development of spit-bar system. A second progradation phase ofthe spit bars systems occurs between 2,400 and 500 BP both in Almería and Cádiz Gulf, where a change from aggradation to progradation takes place in the estuary environments, and with a change in the direction of /ongshore drift (Mediterranean) and prevailing winds (both areas) at ca.2,400 BP. At ca. 1,200 BP a sudden paleogeographic change took place in estuary environments. From 500 BP up to now a marked increase of coastal progradation in ali littorals is observed. Climatic interpretations /ed to corre/ate anticyclonic conditions (as it happened during Little Ice Ages) with the growing of spit bar systems and progradation, while low pressure conditions (as during Medieval Warm Period) coincides with no progradation. In the Canary lslands, the development of storm ridges at ca. 3,500 BP can be corre/ated with an intensification of trade winds.
Comparative study of Cu, Ag and Ag-Cu catalysts over graphite in the ethanol dehydrogenation reaction: Catalytic activity, deactivation and regeneration
(ELSEVIER, 2019) Conesa, J.M.; Morales, María V.; López-Olmos, Cristina; Rodríguez Ramos, Inmaculada; Guerrero Ruíz, Antonio Ricardo; https://orcid.org/0000-0003-2834-0296; https://orcid.org/0000-0003-4622-6008; https://orcid.org/0000-0003-1848-5985
The physicochemical and catalytic properties of bimetallic AgCu catalysts and their monometallic counterparts supported on a high surface area graphite have been comparatively evaluated in the ethanol dehydrogenation reaction, performed in a continuous-flow reactor. While Cu was incorporated by the incipient wetness impregnation technique, for Ag catalysts two synthesis procedures were explored: incipient wetness impregnation and adsorption of Tollens’ reagent. The catalysts prepared by wetness impregnation exhibited higher metal dispersion, being improved for the bimetallic catalysts in comparison with the monometallic counterparts. The results obtained in the catalytic tests revealed that Cu catalysts is nearly two orders of magnitude more active than Ag catalyst in the dehydrogenation reaction of ethanol on either a turnover frequency or a weight basis, but at the same time both catalysts were 100% selective to acetaldehyde. Whereas selectivity was not affected by the bimetallic composition, there was a substantial decrease in the reaction rate among the bimetallic catalysts as the Cu/Ag ratio diminished, due to blockage of copper surface active sites by silver. Both silver and copper, and the bimetallic catalysts, suffered from deactivation at 523 K, caused by blocking of active sites by adsorbed hydrocarbons on the catalyst surface (fouling). Carbonaceous deposits were removed through a thermal treatment under H2 flow, which allowed the total recovery of the initial catalytic activity.
Comparison principles for p-Laplace equations with lower order terms
(Springer Nature, 2016-08-06) Leonori, Tommaso; Porretta, Alessio; Riey, Giuseppe
We prove comparison principles for quasilinear elliptic equations whose simplest model is (Formula presented.), where Δpu=div(|Du|p-2Du) is the p-Laplace operator with p> 2 , λ≥ 0 , H(x, ξ) : Ω × RN→ R is a Carathéodory function and Ω ⊂ RN is a bounded domain, N≥ 2. We collect several comparison results for weak sub- and super-solutions under different setting of assumptions and with possibly different methods. A strong comparison result is also proved for more regular solutions.
Comparison results for unbounded solutions for a parabolic Cauchy-Dirichlet problem with superlinear gradient growth
(American Institute of Mathematical Sciences (AIMS), 2019-05) Leonori, Tommaso; Magliocca, Martina
In this paper we deal with uniqueness of unbounded solutions to the following problem (formula pergented) where QT = (0, T) × Ω is the parabolic cylinder, Ω is an open subset of RN, N ≥ 2, 1 < p < N, and the right hand side H(t, x, ξ): (0, T) × Ω × RN → R exhibits a superlinear growth with respect to the gradient term. © 2019 American Institute of Mathematical Sciences.
Constrained Markov decision processes with non-constant discount factor
(Springer Nature, 2024-05-30) Jasso Fuentes, Héctor; Prieto Rumeau, Tomás
This paper studies constrained Markov decision processes under the total expected discounted cost optimality criterion, with a state-action dependent discount factor that may take any value between zero and one. Both the state and the action space are assumed to be Borel spaces. By using the linear programming approach, consisting in stating the control problem as a linear problem on a set of occupation measures, we show the existence of an optimal stationary Markov policy. Our results are based on the study of both weak-strong topologies in the space of occupation measures and Young measures in the space of Markov policies
Continuous Catalytic Condensation of Ethanol into 1‑Butanol: The Role of Metallic Oxides (M = MgO, BaO, ZnO, and MnO) in Cu-M/ Graphite Catalysts
(ACS Publications, 2020) Lopez Olmos, Cristina; Morales, María V.; Guerrero Ruíz, Antonio Ricardo; Rodríguez Ramos, Inmaculada; https://orcid.org/0000-0003-2834-0296; https://orcid.org/0000-0003-1848-5985; https://orcid.org/0000-0003-4622-6008
Bifunctional catalysts supported over high-surface-area graphite comprising copper and a series of metallic oxides (MgO, BaO, ZnO, or MnO) that exhibit different acid/base properties were studied in the ethanol condensation reaction to 1- butanol in a continuous flow reactor. This condensation reaction goes through the Guerbet mechanism, consisting of a multistep process based on hydrogenation/dehydrogenation reactions as well as base-catalyzed aldol condensation and acid-catalyzed dehydration reactions. The catalytic tests were performed in a fixed-bed reactor working in the gas phase at 50 bar and 503 K. The catalyst 5Cu-Mn/G exhibited the highest yield toward 1-butanol followed closely by 5Cu-Mg/G, unlike their counterparts with BaO and ZnO as the metal oxide. The cooperative action between the metal function as the hydrogenating/dehydrogenating agent and the suitable quantity of medium-high-strength basic sites and medium-weak-strength acid sites is responsible for the highest 1- butanol yields.
Critical Factors Affecting the Selective Transformation of 5-Hydroxymethylfurfural to 3-Hydroxymethylcyclopentanone Over Ni Catalysts
(Chemistry Europe, 2024-06-11) Morales Vargas, María Virtudes; Conesa, José M.; Campos Castellanos, Eduardo; Guerrero Ruiz, Antonio R; Rodríguez Ramos, Inmaculada; https://orcid.org/0000-0003-2834-0296; https://orcid.org/0000-0001-5470-7958; https://orcid.org/0000-0003-4622-6008
The ring-rearrangement of 5-hydroxymethylfurfural (HMF) to 3-hydroxymethylcyclopentanone (HCPN) was investigated over Ni catalysts supported on different carbon supports and metallic oxides with different structure and acid-base properties. Their catalytic performance was tested in a batch stirred reactor in aqueous solution at 180 °C and 30 bar of H2. Under these conditions, the HMF hydrogenation proceeds through three possible competitive routes: (i) a non-water path leading to the total hydrogenation product, 2,5-di-hydroxymethyl-tetrahydrofuran (DHMTHF), and two parallel acid-catalyzed water-mediated routes responsible for (ii) ring-opening and (iii) ring-rearrangement reaction products. All catalyst systems primarily produced HCPN, but reaction rates and product distribution were influenced by several variables, some of them intensely analyzed in this work. The most proper conditions resulted to be the presence of the medium/strong Lewis's acidity of a Ni/ZrO2 catalyst (initial TOF=5.99 min−1 and 73 % HCPN selectivity) or the Brønsted acidity originated by an oxidized high surface area graphite, Ni/HSAG-ox (initial TOF=5.92 min−1 and 87 % HCPN selectivity). However, too high density of acidic sites on the catalyst support (Ni/Al2O3) and sulfur impurities from the HMF feedstock led to catalyst deactivation by coke deposition and Ni poisoning, respectively.
Cu and Pd nanoparticles supported on a graphitic carbon material as bifunctional HER/ORR electrocatalysts
(ELSEVIER, 2020-11-01) Nunes, Marta S.; Fernandes, Diana M.; Morales, M. V.; Rodríguez Ramos, Inmaculada; Guerrero Ruíz, Antonio Ricardo; Freire, Cristina; https://orcid.org/0000-0002-0460-451X; https://orcid.org/0000-0001-5263-2737; https://orcid.org/0000-0003-2834-0296; https://orcid.org/0000-0003-4622-6008; https://orcid.org/0000-0003-1848-5985
The development of efficient, available and robust substitutes for the Pt-based electrocatalysts is very important for a sustainable energetic future. Herein, we report a series of composites based on Cu, Pd and Cu-Pd nanoparticles (NPs) supported on high surface area graphite (HSAG), as electrocatalysts for the energy-related reduction reactions – oxygen reduction (ORR) and hydrogen evolution (HER) reactions. All the composites showed interesting ORR electrocatalytic activities in alkaline medium. The Pd/HSAG and Cu-Pd/HSAG composites exhibited the most promising performances, with onset potentials of 0.84 and 0.91 V and current densities of jL, 0.3 V, 1600 rpm=−3.5 and −4.2 mA cm−2, respectively. All the composites showed selectivity for the 4-electron process and Tafel slopes in the range 48–77 mV dec−1. The metal/HSAG composites revealed a great tolerance to methanol and moderate electrochemical stability. In highly acidic medium (0.5 mol dm−3 H2SO4, pH=0.3) only the Cu-Pd/HSAG and Pd/HSAG electrocatalysts presented electrocatalytic activity toward HER, with relative low overpotentials (η10=0.145 and 0.063 V, respectively), small Tafel slopes (75 and 42 mV dec−1) and similar exchange current densities (0.43 and 0.57 mA cm−2). These electrocatalysts also showed moderate electrochemical stability, in particular Cu-Pd/ HSAG for which overpotential only changed between 0.033 and 0.038 V for j=40mAcm−2. The results showed that only small loading of Pd NPs (1 wt.% Pd) was able to improve significantly the ORR/ HER electrocatalytic activity, which is a very important outcome to rationalize the design of efficient and costeffective electrocatalysts in future.
Detecting ultraviolet C radiation under polyethylene terephthalate (PET) packaging by thermoluminescence analysis using commercial dosimeters
(Elsevier, 2024-03-07) Correcher, V.; Boronat Castaño, Cecilia; Bravo Yagüe, Juan Carlos
Food irradiation is a proven technology that enhances food quality and safety by removing microorganisms and extending shelf life. Ultraviolet C radiation (UVC) has recently attracted interest due to its potential to inactivate foodborne pathogens. It relies on several advantages; however, there is limited research on its efficacy and safety particularly concerning food packaging materials such as polyethylene terephthalate (PET). This study reports on the effect of UVC radiation on commercial thermoluminescence dosimeters (namely, TLD-100, TLD-200, TLD-400 and GR-200) placed under PET films with different thicknesses (0.10, 0.42, and 0.60 mm). The results indicate the potential use of these materials for the detection of UVC radiation passing through the randomly selected PET samples. Fourier transform infrared spectroscopy assesses potential structural and chemical alterations in the PET induced by UVC exposure.

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