El doctor en química D. Jorge Rencoret Pazos galardonado con el premio de investigación 'Real Maestranza de Caballeria de Sevilla' a investigadores jóvenes en su convocatoria de 2012

2 páginas.-- Artículo sobre la entrega del premio de investigación convocado en 2012 para investigadores jóvenes por la "Real Maestranza de Caballería" de Sevilla. Escrito por el Dr. Pedro J. Sánchez Sot

A Robotic Hyperspectral Scanning Framework for Endoscopy

Gastrointestinal (GI) endoscopy is the gold-standard procedure for detection and treatment of dysplastic lesions and early stage GI cancers. Despite its proven effectiveness, its sensitivity remains suboptimal due to the subjective nature of the examination, which is substantially reliant on human-operator skills. For bowel cancer, colonoscopy can miss up to 22% of dysplastic lesions, with even higher miss rates for small (<5 mm diameter) and flat lesions. We propose a robotic hyperspectral (HS) scanning framework that aims to improve the sensitivity of GI endoscopy by automated scanning and real-time classification of wide tissue areas based on their HS features. A “hot-spot” map is generated to highlight dysplastic or cancerous lesions for further scrutiny or concurrent resection. The device works as an add-on accessory to any conventional endoscope, and to our knowledge, is the first of its kind. This paper focuses on characterising its optical resolution on rigid and deformable colon phantoms. We report for the first time 2D and 3D wide-area reconstruction of endoscopic HS data with sub-millimetre optical resolution. The current setup, compatible with the anatomical dimensions of the colon, could allow the identification of flat and small pre-cancerous lesions that are currently missed. The proposed framework will lay the foundations towards the next generation of augmented reality endoscopy while increasing its sensitivity and specificity

Revisiting neutron starquakes caused by spin-down

Pulsars show a steady decrease in their rotational frequency, occasionally interrupted by sudden spin-ups called glitches, whose physical origin is still a mystery. One suggested explanation for at least the small glitches are starquakes, that is, failures of the solid neutron star crust, in which the progressive reduction in the centrifugal force deforms the star, stressing the solid until it breaks. This produces a spin-up, dissipating energy inside the star. We analyze the deformations produced by the decreasing centrifugal force, modeling the star with a fluid core and a solid crust, each with uniform density and with the core possibly denser than the crust, as a simple approximation to the strong density gradient present in real neutron stars. The deformation is qualitatively different from the previously studied case of equal densities. The former more closely resembles the behavior of a fluid star, in which the core-crust interface is a surface of constant gravitational plus centrifugal potential. Regardless of the uncertain breaking strain, the glitch activity in this model is several orders of magnitude smaller than observed, even if only small glitches are considered. For a large breaking strain, suggested by simulations, glitches due to starquakes could be roughly of the correct size but much less frequent than observed glitches. The energy released in each glitch is much larger than in the model of angular momentum transfer from a faster rotating superfluid in the inner crust. On the other hand, we cannot rule out that the heating produced by small starquakes could trigger glitches by allowing neutron superfluid vortices to move. We also confirm that stresses in the neutron star crust can in principle support an ellipticity much larger than some observational upper limits from pulsar timing and continuous gravitational wave searches.Comment: 17 pages, 11 figure

Maize tricin-oligolignol metabolites and their implications for monocot lignification

Lignin is an abundant aromatic plant cell wall polymer consisting of phenylpropanoid units in which the aromatic rings display various degrees of methoxylation. Tricin [5,7-dihydroxy-2-(4-hydroxy-3,5-dimethoxyphenyl)-4H-chromen-4-one], a flavone, was recently established as a true monomer in grass lignins. To elucidate the incorporation pathways of tricin into grass lignin, the metabolites of maize (Zea mays) were extracted from lignifying tissues and profiled using the recently developed 'candidate substrate product pair' algorithm applied to ultra-high-performance liquid chromatography and Fourier transform-ion cyclotron resonance-mass spectrometry. Twelve tricin-containing products (each with up to eight isomers), including those derived from the various monolignol acetate and p-coumarate conjugates, were observed and authenticated by comparisons with a set of synthetic tricin-oligolignol dimeric and trimeric compounds. The identification of such compounds helps establish that tricin is an important monomer in the lignification of monocots, acting as a nucleation site for starting lignin chains. The array of tricin-containing products provides further evidence for the combinatorial coupling model of general lignification and supports evolving paradigms for the unique nature of lignification in monocots

Robotic large-area optical biopsy imaging for automated detection of gastrointestinal cancers tested in tissue phantoms and ex vivo porcine bowel

Gastrointestinal endoscopy is a subjective procedure that frequently requires tissue samples for diagnosis. Contact optical biopsy (OB) techniques have the aim of providing direct diagnosis of endoscopic areas without excising tissue samples but lack the wide-area coverage required for locating and resecting lesions. This article presents a large-area robotically deployed OB imaging platform for endoscopic detection of colorectal cancer as an add-on for conventional endoscopes. In vitro, in silicon colon phantoms, the platform achieves an optical resolution of 0.5 line pairs per millimeter, while resolving simulated cancer lesions down to 0.75 mm diameter across large-area images (55-103 cm2). Large-area OB images were generated in an ex vivo porcine colon. The platform allows centimeter-sized large-area OB imaging in vitro and ex vivo with submillimeter resolution, including automatic data segmentation of simulated cancer areas. The ability for robotic actuation and spectrum collection is also shown for ex vivo animal colon. If successful, this technology could widen access to user-independent high-quality endoscopy and early detection of gastrointestinal cancers

Hydra Clothes

Tesis (Diseñador Industrial)El proyecto de título tiene como principal objetivo ser un real aporte para los deportista de alta montaña en deportes blancos centrándose en la hidratación, ya que es vital para mantenerse activo y recuperar energías perdidas durante el ejercicio. Debido a lo anterior, propongo un proyecto para mejorar la experiencia del deportista en cuanto a la elaboración, sensación y carga trasladada, reduciendo contenedores sueltos y facilitando la hidratación en cualquier momento del día. Por lo tanto, el fin último es entregarle al deportista de la alta montaña, una sensación de libertar, distribuyendo de mejor manera el peso y a su vez eliminando el accesorio externo (mochila) lo que perjudica en un buen equilibrio y libertad de movimiento para el deportista

Cambios en el mapa mediático del ecuador: los medios públicos que tenemos y los medios que queremos

The public media system of Ecuador consists of 22 mass media organizations with diverse origins and structures, constituting a new power without clear limits that tries to compete with private and traditional mass media organizations whose administration has a family, monopolistic character. Public media organizations in Ecuador are far from the universal characteristics proposed for this type of media, basically, due to their closeness to State organizations. The competition between private and government media groups is unequal, a situation that modifies the national media agenda, exposing some of the weaknesses and limitations of journalistic work and the handling of journalistic enterprises, in particular. This article is based in a descriptive analysis of the communications media in Ecuador and the power game that the presence of public media has unleashed in this last decade. It also analyzes the role of journalism and its position confronting vital issues for the country, showing the lack of a comprehensive policy that favors citizens and weaknesses in the journalism profession. It concludes with recommendations for improving the role of media in Ecuador. &nbsp;El sistema de medios públicos en Ecuador está compuesto por 22 medios de diferente origen y estructura, constituyéndose un poder nuevo y sin límites claros, que intenta competir con medios privados y tradicionales del país, cuya administración es de carácter familiar y monopólico. Los medios públicos en Ecuador distan de las características universales planteadas para este tipo de medios, básicamente por la cercanía con los organismos del Estado, en general. La competencia entre medios públicos y privados es desigual, situación que modifica la agenda mediática nacional, dejando a la luz algunas debilidades y limitaciones del ejercicio periodístico y del manejo de la empresa periodística, en particular. El presente artículo se fundamenta en un análisis descriptivo de los medios de comunicación en Ecuador y el juego de poderes que ha desatado la presencia de medios públicos en esta última década. Analizan también el rol del periodismo y su posición frente a los temas vitales para el país, evidenciando la ausencia de una política integral a favor del ciudadano y debilidades en la profesión periodística. Concluye con recomendaciones para mejorar el papel de los medios en Ecuador. &nbsp

Laccase-Mediator Pretreatment of Wheat Straw Degrades Lignin and Improves Saccharification

14 páginas.-- 4 figuras.-- 4 tablas.-- 49 referenciasThe authors thank Dr. Angulo for performing the NMR analyses that were acquired on a Bruker AVANCE III 500-MHz instrument from the NMR facilities of the General Research Services of the University of Seville (SGI CITIUS)gricultural by-products such as wheat straw are attractive feedstocks for the production of second-generation bioethanol due to their high abundance. However, the presence of lignin in these lignocellulosic materials hinders the enzymatic hydrolysis of cellulose. The purposes of this work are to study the ability of a laccase-mediator system to remove lignin improving saccharification, as a pretreatment of wheat straw, and to analyze the chemical modifications produced in the remaining lignin moiety. Up to 48 % lignin removal from ground wheat straw was attained by pretreatment with Pycnoporus cinnabarinus laccase and 1-hydroxybenzotriazole (HBT) as mediator, followed by alkaline peroxide extraction. The lignin removal directly correlated with increases (∼60 %) in glucose yields after enzymatic saccharification. The pretreatment using laccase alone (without mediator) removed up to 18 % of lignin from wheat straw. Substantial lignin removal (37 %) was also produced when the enzyme-mediator pretreatment was not combined with the alkaline peroxide extraction. Two-dimensional nuclear magnetic resonance (2D NMR) analysis of the whole pretreated wheat straw material swollen in dimethylsulfoxide-d6 revealed modifications of the lignin polymer, including the lower number of aliphatic side chains involved in main β-O-4′ and β-5′ inter-unit linkages per aromatic lignin unit. Simultaneously, the removal of p-hydroxyphenyl, guaiacyl, and syringyl lignin units and of p-coumaric and ferulic acids, as well as a moderate decrease of tricin units, was observed without a substantial change in the wood polysaccharide signals. Especially noteworthy was the formation of Cα-oxidized lignin units during the enzymatic treatment.This study was funded by the INDOX EU-project (KBBE-2013-7-613549); the LIGNOCELL, LIGNIN, NOESIS, and BIORENZYMERY Spanish MICINN (co-financed by FEDER funds) projects (AGL2011-25379, CTQ2014-60764-JIN, BIO2014-56388 R and AGL2014-53730-R); and the CSIC (201440E097) Project. A.P. thanks the Spanish MINECO for a FPI fellowship. A. Lomascolo and E. Record from INRA (Marseille, France) are acknowledged for the P. cinnabarinus laccase, and H. Lund and M. Tovborg from Novozymes (Bagsvaerd, Denmark) for Celluclast 1.5L and Novozyme 188.Peer reviewe

Deciphering the unique structure and acylation pattern of Posidonia oceanica lignin

Copyright © 2020 American Chemical Society. Lignins from different parts of the seagrass Posidonia oceanica-namely sheaths, rhizome, and roots-as well as from fibrous balls from P. oceanica detritus were isolated and thoroughly characterized by pyrolysis coupled with gas chromatography/mass spectrometry, derivatization followed by reductive cleavage, two-dimensional nuclear magnetic resonance spectroscopy, and gel permeation chromatography. The lignins of P. oceanica were enriched in guaiacyl (G) over syringyl (S) units, with S/G ratios ranging from 0.1 (fibrous balls) to 0.5 (rhizome). β-O-4′ ethers and phenylcoumarans were the most abundant lignin substructures, followed by resinols, and minor amounts of dibenzodioxocins and spirodienones. Moreover, all lignins were found to be highly I-Acylated (up to 44% of total units), mainly with p-hydroxybenzoates but also, to a lesser extent, with acetates. The data indicated that this acylation extensively occurred in both G-and S-lignin units, contrary to what happens in palms, poplar, and willow, where p-hydroxybenzoates overwhelmingly appear at the I-position of S-units

Lignin from tree barks: chemical structure and valorization

Lignins from different tree barks, including Norway spruce (Picea abies), eucalyptus (Eucalyptus globulus), mimosa (Acacia dealbata) and blackwood acacia (A. melanoxylon), are thoroughly characterized. The lignin from E. globulus bark is found to be enriched in syringyl (S) units, with lower amounts of guaiacyl (G) and p-hydroxyphenyl (H) units (H/G/S ratio of 1:26:73), which produces a lignin that is highly enriched in bether linkages (83%), whereas those from the two Acacia barks have similar compositions (H/G/S ratio of &5:50:45), with a predominance of b-ethers (73–75%) and lower amounts of condensed carbon–carbon linkages; the lignin from A. dealbata bark also includes some resorcinol-related compounds, that appear to be incorporated or intimately associated to the polymer. The lignin from P. abies bark is enriched in G units, with lower amounts of H units (H/G ratio of 14:86); this lignin is thus depleted in b-O-4’ alkyl–aryl ether linkages (44%) and enriched in condensed linkages. Interestingly, this lignin contains large amounts of hydroxystilbene glucosides that seem to be integrally incorporated into the lignin structure. This study indicates that lignins from tree barks can be seen as an interesting source of valuable phenolic compounds. Moreover, this study is useful for tailoring conversion technologies for bark deconstruction and valorizationinfo:eu-repo/semantics/publishedVersio