On Brusselator and Oregonator as chemical reaction networks: a graph approach

"This paper shows graph similarities between Brusselator and Oregonator reaction mechanisms, using the jacobian matrix in convex coordinates as an adjacency matrix which defines a weighted directed pseudograph. A linear transformation is defined for the task of mapping the weights of the three dimensional system onto a two dimensional one where the Oregonator´s pseudograph is isomorphic to Brusselator´s.

Steady state equivalence among autocatalytic peroxidase-oxidase reactions

"Peroxidase-oxidase is an enzymatic reaction that can exhibit dynamical scenarios such as bistability, sustained oscillations, and Shilnikov chaos. In this work, we apply the chemical reaction network theory approach to find kinetic constants such that the associated mass action kinetics ordinary differential equations induced by three four dimensional structurally different enzymatic reaction systems can support the same steady states for several chemical species despite differences in their chemical nature.

A chemical representation of a chaotic system with a unique stable equilibrium point

"In this paper we present a chemical representation of a chaotic system with only one stable equilibrium point. The approach invokes cooperative catalysis and slow-fast reactions, primarily. The obtained chemical based chaotic dynamical system preserves the eigenvalues of the unique and stable equilibrium point along with the Lyapunov’s dimension and exponents of the original one.

Tecnologías de la Información (TICs) y aulas virtuales en la enseñanza de la ortodoncia y odontopediatría

El alto nivel de desarrollo y de accesibilidad que en la actualidad han alcanzado las denominadas tecnologías de la información y la comunicación (TICs) han posibilitado una mejora sustancial en cualquiera de las facetas educativas del aprendizaje virtual. Gracias a las TICs, la enseñanza a distancia es cada vez más eficiente y atrayente para los alumnos, mejorando su motivación y rendimiento, lo que se traduce en un incremento en la adquisición de conocimientos, de habilidades, y actitudes. En el caso de la enseñanza virtual de la odontopediatría, el uso de algunas aplicaciones específicas como es la realidad aumentada, que permite realizar prácticas en pacientes virtuales, consiguen que el alumno mejore sus habilidades psicomotrices, e incremente sus aptitudes y confianza a la hora de tratar y resolver problemas reales. En el caso de la ortodoncia, la creación y manipulación de modelos digitales en tres dimensiones, ayuda al alumno a comprender y a interpretar las características diagnósticas y correctivas de los diferentes casos clínicos

Improving the performance of a bioelectronic tongue using silver nanowires. Application to milk analysis

Producción CientíficaRecent advances in the field of electronic tongues (ET) are linked to the development of devices dedicated to a particular application. Following this idea, we have developed a voltammetric bioelectronic tongue (bioET) specifically dedicated to analyze milk. The performance of the multisensor system has been improved by incorporating biosensors combining specific enzymes for the detection of sugars present in milk (β-galactosidase, glucose oxidase and galactose oxidase) with silver nanomaterials. It has been demonstrated that silver nanowires (AgNWs) provide a more effective platform for the immobilization of biomolecules than silver nanoparticles (AgNPs), inducing unique performance characteristics in terms of sensitivity and detection limits. Two multisensor systems have been developed; one based on combinations of AgNWs and enzymes (AgNW/bioET) and a second based on combinations of AgNPs and enzymes (AgNP/bioET). Principal component analysis (PCA) demonstrates that the bioET based on combinations of AgNWs and enzymes (AgNW/bioET) can discriminate 9 classes of milk with different fat content (skimmed, semi-skimmed and whole), as well as different nutritional compositions (classic, calcium-enriched and lactose-free), with a higher capacity than the bioET based on combinations of AgNPs and enzymes (AgNP/bioET). Support vector machine (SVMR) models show excellent correlation coefficients between the responses of the bioETs and physicochemical parameters commonly used to evaluate the quality of milk (acidity, density, fat, proteins, lactose, total dry matter and non-fat dry matter). The good results obtained support the dairy industry’s interest in dedicated bioETs, not only for classification purposes but also to obtain information concerning several physicochemical parameters in a singleMinisterio de Economía, Industria y Competitividad - Fondo Europeo de Desarrollo Regional (project RTI2018-097990-B-100)Junta de Castilla y León - Fondo Europeo de Desarrollo Regional (project VA202P20)Infraestructuras Red de Castilla y León (INFRARED) UVA01 - Unión Europea - Fondo Europeo de Desarrollo Regional (project CLU-2019-04)Ministerio de Ciencia, Innovación y Universidades (fellowship AGL 2015-67482_R

A 3D Peptide/[60]Fullerene Hybrid for Multivalent Recognition

Multivalent ligand presentation is a powerful strategy for the development of specific binders and inhibitors. Peptide/[60]fullerene hybrids have now been synthesized that exploit the complete substitution of the fullerene scaffold to afford globular structures presenting twelve copies of a peptide ligand for the recognition of E-selectin. Fully substituted peptide/[60]fullerene hexakis-adducts offer an excellent opportunity for multivalent protein recognition. In contrast to monofunctionalized fullerene hybrids, peptide/[60]fullerene hexakis-adducts display multiple copies of a peptide in close spatial proximity and in the three dimensions of space. High affinity peptide binders for almost any target can be currently identified by in vitro evolution techniques, often providing synthetically simpler alternatives to natural ligands. However, despite the potential of peptide/[60]fullerene hexakis-adducts, these promising conjugates have not been reported to date. Here we present a synthetic strategy for the construction of 3D multivalent hybrids that are able to bind with high affinity the E-selectin. The here synthesized fully substituted peptide/[60]fullerene hybrids and their multivalent recognition of natural receptors constitute a proof of principle for their future application as functional biocompatible materialsThis work was partially supported by the Spanish Agencia Estatal de Investigación (AEI) [SAF2017-89890-R, PCI2019-103400, PID2020-117143RB-I00, PID2020-114653RB-I00 and PID2020-115120GB-I00], Xunta de Galicia (ED431C 2017/25 and Centro singular de investigación de Galicia accreditation 2019–2022, ED431G 2019/03) and the European Commission (EC) (European Regional Development Fund-ERDF). J.M. thanks the ERC-STG (DYNAP, 677786), ERC-POC (TraffikGene, 838002), Xunta de Galicia (Oportunius Program) and Human Frontier Science Programme Young Investigator Grant (RGY0066/2017) for funding. J.J.R. received a Beatriz Galindo Grant (BEAGAL18-00051) by the Spanish Ministerio de Universidades. I.G. received predoctoral fellowships (ED481A-2018/116 and FPU17/00941). J.C.-G. thanks the Comunidad de Madrid Atracción de Talento program (2018-T2/BMD-10275)S

Experimental Techniques to Measure Hypnotic Levels During Surgery

[Abstract] The administration of anesthetics during a surgical procedure has been done historically in a manual way with the anesthesiologist deciding what amounts and at what rates to use. Over the last few decades there has been a rapid increase in the automation of many medical areas including anesthesiology, with that increased level of automation have also appeared new ways to measure the level of sedation in patients. Historically, one of the most frequently index used has been the BIS, which has proven rather reliable as an indicator. More recently, another index called PSI has attracted interest of practitioners. In this article a comparison of these two indexes was performed. Data recording BIS and PSI values from surgical operations for several patients were collected and analyzed. The results seem to indicate that it is to be expected that in 95% of the cases the correlation between the BIS and PSI index will be at least 0.6866.This work has been supported by the grant DPI2010-18278 of the Spanish Governmenthttps://doi.org/10.17979/spudc.978849749808

Low prevalence of vancomycin-resistant enterococci in clinical samples from hospitalized patients of the Canary Islands, Spain

Over the last decade vancomycin-resistant enterococci (VRE) have emerged as nosocomial pathogens. The aim of this study was to determine the prevalence of VRE in clinical samples from hospitalized patients in the Canary Islands. From April to November 2000, 437 enterococci were isolated from patients hospitalized at the four main health care centers in those islands. Identification to the species level was performed with the GPS-TA (Vitek 1) or the Wider I system. A PCR assay was used to determine the genotype of glycopeptide resistance (vanA, vanB, vanC1, and vanC2/C3 genes). Only three (0.7%) VRE were detected: one vanA Enterococcus faecalis, and two vanC1 Enterococcus gallinarum. To our knowledge, this is the first VRE study carried out in the Canary Islands hospitals, and the results showed a low prevalence of VRE

Electronic Noses and Tongues in Wine Industry

Producción CientíficaThe quality of wines is usually evaluated by a sensory panel formed of trained experts or traditional chemical analysis. Over the last few decades, electronic noses (e-noses) and electronic tongues have been developed to determine the quality of foods and beverages. They consist of arrays of sensors with cross-sensitivity, combined with pattern recognition software, which provide a fingerprint of the samples that can be used to discriminate or classify the samples. This holistic approach is inspired by the method used in mammals to recognize food through their senses. They have been widely applied to the analysis of wines, including quality control, aging control, or the detection of fraudulence, among others. In this paper, the current status of research and development in the field of e-noses and tongues applied to the analysis of wines is reviewed. Their potential applications in the wine industry are described. The review ends with a final comment about expected future developments.CM-P agradece a la Universidad de Valladolid por su beca PIF-UVa y CG-H por su contrato pre-doctoral JCYL (BOCYL-D-24112015-9).Ministerio de Economía, Industria y Competitividad – FEDER (Grant AGL2015-67482-R)Junta de Castilla y León (programa de apoyo a proyectos de investigación - Ref. VA-032U13

An Electrochemical Quartz Crystal Microbalance Multisensor System Based on Phthalocyanine Nanostructured Films: Discrimination of Musts

Producción CientíficaAn array of electrochemical quartz crystal electrodes (EQCM) modified with nanostructured films based on phthalocyanines was developed and used to discriminate musts prepared from different varieties of grapes. Nanostructured films of iron, nickel and copper phthalocyanines were deposited on Pt/quartz crystals through the Layer by Layer technique by alternating layers of the corresponding phthalocyanine and poly-allylamine hydrochloride. Simultaneous electrochemical and mass measurements were used to study the mass changes accompanying the oxidation of electroactive species present in must samples obtained from six Spanish varieties of grapes (Juan García, Prieto Picudo, Mencía Regadío, Cabernet Sauvignon, Garnacha and Tempranillo). The mass and voltammetric outputs were processed using three-way models. Parallel Factor Analysis (PARAFAC) was successfully used to discriminate the must samples according to their variety. Multi-way partial least squares (N-PLS) evidenced the correlations existing between the voltammetric data and the polyphenolic content measured by chemical methods. Similarly, N-PLS showed a correlation between mass outputs and parameters related to the sugar content. These results demonstrated that electronic tongues based on arrays of EQCM sensors can offer advantages over arrays of mass or voltammetric sensors used separately.Ministerio de Economía, Industria y Competitividad – FEDER (Grant CICYT AGL2012-33535)Junta de Castilla y León (programa de apoyo a proyectos de investigación - Ref. VA-032U13)University of Valladolid (PIF-UVa