94 research outputs found

    Pyrrolidine-based catalytic microporous polymers in sustainable C=N and C=C bond formation via iminium and enamine activation

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    Producción CientíficaA new set of catalytic materials having a pyrrolidine moiety confined in microporous organic polymer networks (POPs) has been attained. These catalytic polymers have been prepared by a straightforward synthesis starting from microporous polymer networks made from isatin (or a mixture of isatin and trifluoroacetophenone) and 1,3,5-triphenylbenzene. The polymers efficiently catalyzed the formation of nitrones under very mild and sustainable conditions using green solvents through an iminium ion activation mechanism. The reactions are scalable, and polymers are easily recycled. Special attention has been paid to understanding all the factors that could affect the efficiency of the confined catalysts. The electronic and conformational characteristics of the pyrrolidine moiety attached to the porous polymers, as well as other features that could affect the transport through the network, such as molecular volume and shape of reactants and products, and even hydrophilic or hydrophobic properties, have been systematically evaluated. In addition, the heterogeneous polymers are also useful in Cdouble bondC bond formation through both iminium ion and enamine activation.Gobierno de España (Agencia Estatal de Investigación) - (Projects CTQ2016-78779-R, PID2019-109403RB-C22, RTI2018-096328-B-I00, CTQ2017-89217-P and PID2020-118547GBI00)Junta de Castilla y León, Unión Europea y Fondo Europeo de Desarrollo Regional (FEDER) - (Project VA224P20)

    Current perspectives on the use of anti-VEGF drugs as adjuvant therapy in glaucoma

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    The approval of one of the first anti-vascular endothelial growth factor (VEGF) agents for the treatment of neovascular age-related macular degeneration one decade ago marked the beginning of a new era in the management of several sight-threatening retinal diseases. Since then, emerging evidence has demonstrated the utility of these therapies for the treatment of other ocular conditions characterized by elevated VEGF levels. In this article we review current perspectives on the use of anti-VEGF drugs as adjuvant therapy in the management of neovascular glaucoma (NVG). The use of anti-VEGFs for modifying wound healing in glaucoma filtration surgery (GFS) is also reviewed. Selected studies investigating the use of anti-VEGF agents or antimetabolites in GFS or the management of NVG have demonstrated that these agents can improve surgical outcomes. However, anti-VEGF agents have yet to demonstrate specific advantages over the more established agents commonly used today. Further studies are needed to evaluate the duration of action, dosing intervals, and toxicity profile of these treatments

    P and R Wave Detection in Complete Congenital Atrioventricular Block

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    Complete atrioventricular block (type III AVB) is characterized by an absence of P wave transmission to ventricles. This implies that QRS complexes are generated in an autonomous way and are not coordinated with P waves. This work introduces a new algorithm for the detection of P waves for this type of pathology using non-invasive electrocardiographic surface leads. The proposed algorithm is divided into three stages. In the first stage, the R waves located by a QRS detector are used to generate the RR series and time references for the other stages of the algorithm. In the second stage, the ventricular activity (QT segment) is removed by using an adaptive filter that obtains an averaged pattern of the QT segment. In the third stage, a new P wave detector is applied to the residual signal obtained after QT cancellation in order to detect P wave locations and get the PP time series. Eight Holter records from patients with congenital type III AVB were used to verify the proposed algorithm. Although further improvements should be made to improve the algorithmÂżs performance, the results obtained show high average values of sensitivity (90.52 %) and positive prediction (90.98%)

    On the Use of Unmanned Aerial Systems for Environmental Monitoring

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    [EN] Environmental monitoring plays a central role in diagnosing climate and management impacts on natural and agricultural systems; enhancing the understanding of hydrological processes; optimizing the allocation and distribution of water resources; and assessing, forecasting, and even preventing natural disasters. Nowadays, most monitoring and data collection systems are based upon a combination of ground-based measurements, manned airborne sensors, and satellite observations. These data are utilized in describing both small-and large-scale processes, but have spatiotemporal constraints inherent to each respective collection system. Bridging the unique spatial and temporal divides that limit current monitoring platforms is key to improving our understanding of environmental systems. In this context, Unmanned Aerial Systems (UAS) have considerable potential to radically improve environmental monitoring. UAS-mounted sensors offer an extraordinary opportunity to bridge the existing gap between field observations and traditional air-and space-borne remote sensing, by providing high spatial detail over relatively large areas in a cost-effective way and an entirely new capacity for enhanced temporal retrieval. As well as showcasing recent advances in the field, there is also a need to identify and understand the potential limitations of UAS technology. For these platforms to reach their monitoring potential, a wide spectrum of unresolved issues and application-specific challenges require focused community attention. Indeed, to leverage the full potential of UAS-based approaches, sensing technologies, measurement protocols, postprocessing techniques, retrieval algorithms, and evaluation techniques need to be harmonized. The aim of this paper is to provide an overview of the existing research and applications of UAS in natural and agricultural ecosystem monitoring in order to identify future directions, applications, developments, and challenges.The present work has been funded by the COST Action CA16219 "HARMONIOUS-Harmonization of UAS techniques for agricultural and natural ecosystems monitoring". B. Toth acknowledges financial support by the Hungarian National Research, Development and Innovation Office (NRDI) under grant KH124765. J. Millerovd was supported by projects GA17-13998S and RVO67985939. Isabel and Jodo de Lima were supported by project HIRT (PTDC/ECM-HID/4259/2014-POCI-0145-FEDER016668).Manfreda, S.; Mccabe, MF.; Miller, PE.; Lucas, R.; Pajuelo Madrigal, V.; Mallinis, G.; Ben Dor, E.... (2018). On the Use of Unmanned Aerial Systems for Environmental Monitoring. Remote Sensing. 10(4):1-28. https://doi.org/10.3390/rs10040641S12810

    Roadmap on holography

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    From its inception holography has proven an extremely productive and attractive area of research. While specific technical applications give rise to 'hot topics', and three-dimensional (3D) visualisation comes in and out of fashion, the core principals involved continue to lead to exciting innovations in a wide range of areas. We humbly submit that it is impossible, in any journal document of this type, to fully reflect current and potential activity; however, our valiant contributors have produced a series of documents that go no small way to neatly capture progress across a wide range of core activities. As editors we have attempted to spread our net wide in order to illustrate the breadth of international activity. In relation to this we believe we have been at least partially successful.This work was supported by Ministerio de EconomĂ­a, Industria y Competitividad (Spain) under projects FIS2017-82919-R (MINECO/AEI/FEDER, UE) and FIS2015-66570-P (MINECO/FEDER), and by Generalitat Valenciana (Spain) under project PROMETEO II/2015/015

    Effective Gene Therapy in a Mouse Model of Prion Diseases

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    Classical drug therapies against prion diseases have encountered serious difficulties. It has become urgent to develop radically different therapeutic strategies. Previously, we showed that VSV-G pseudotyped FIV derived vectors carrying dominant negative mutants of the PrP gene are efficient to inhibit prion replication in chronically prion-infected cells. Besides, they can transduce neurons and cells of the lymphoreticular system, highlighting their potential use in gene therapy approaches. Here, we used lentiviral gene transfer to deliver PrPQ167R virions possessing anti-prion properties to analyse their efficiency in vivo. Since treatment for prion diseases is initiated belatedly in human patients, we focused on the development of a curative therapeutic protocol targeting the late stage of the disease, either at 35 or 105 days post-infection (d.p.i.) with prions. We observed a prolongation in the lifespan of the treated mice that prompted us to develop a system of cannula implantation into the brain of prion-infected mice. Chronic injections of PrPQ167R virions were done at 80 and 95 d.p.i. After only two injections, survival of the treated mice was extended by 30 days (20%), accompanied by substantial improvement in behaviour. This delay was correlated with: (i) a strong reduction of spongiosis in the ipsilateral side of the brain by comparison with the contralateral side; and (ii) a remarkable decrease in astrocytic gliosis in the whole brain. These results suggest that chronic injections of dominant negative lentiviral vectors into the brain, may be a promising approach for a curative treatment of prion diseases

    International lower limb collaborative (INTELLECT) study: a multicentre, international retrospective audit of lower extremity open fractures

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    Trauma remains a major cause of mortality and disability across the world1, with a higher burden in developing nations2. Open lower extremity injuries are devastating events from a physical3, mental health4, and socioeconomic5 standpoint. The potential sequelae, including risk of chronic infection and amputation, can lead to delayed recovery and major disability6. This international study aimed to describe global disparities, timely intervention, guideline-directed care, and economic aspects of open lower limb injuries

    Roadmap on holography

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    From its inception holography has proven an extremely productive and attractive area of research. While specific technical applications give rise to 'hot topics', and three-dimensional (3D) visualisation comes in and out of fashion, the core principals involved continue to lead to exciting innovations in a wide range of areas. We humbly submit that it is impossible, in any journal document of this type, to fully reflect current and potential activity; however, our valiant contributors have produced a series of documents that go no small way to neatly capture progress across a wide range of core activities. As editors we have attempted to spread our net wide in order to illustrate the breadth of international activity. In relation to this we believe we have been at least partially successful

    Outcomes from elective colorectal cancer surgery during the SARS-CoV-2 pandemic

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    This study aimed to describe the change in surgical practice and the impact of SARS-CoV-2 on mortality after surgical resection of colorectal cancer during the initial phases of the SARS-CoV-2 pandemic

    Modelling the potential impacts of climate change on the hydrology of the Aipe river basin in Huila, Colombia

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    [EN] The dynamics of a global world, and humans performing as a new geological force, require that an effort is undertaken to make robust decisions in order to devise strategies for the management and adaptation to climate change. This study aims to investigate the potential impact of climate change on the hydrology of the Aipe river basin in Huila, Colombia. The abcd Thomas model (four parameters) was calibrated and validated for the stream flows of the Aipe catchment (1992Âż2012). The sensitivity and identifiability of the parameters were evaluated using the Monte Carlo Analysis Toolbox (MCAT). The results show the ability of the model to simulate the monthly stream flow (NashÂżSutcliffe efficiency coefficient of 0,89). The most influential parameters are: a (water storage in the soil) and c (contribution to the aquifer). From the simulated scenarios, the baseline (1992Âż2012) was estimated to be an average flow of 15,44 m3sÂż1; the trend extrapolation scenario estimated a rate 13,79 m3sÂż1 (Âż10,64%); while for the multi-model assembly scenario it was 9,34 m3sÂż1 (Âż39,47%) and for the A2 scenario it was 5,74 m3sÂż1 (Âż62,60%). Lastly, we propose a set of strategies for adaptation to climate change that are committed to the integral management of water resources.[ES] La dinĂĄmica de un mundo global y el hombre como nueva fuerza geolĂłgica plantean la necesidad de tomar decisiones robustas, diseñar estrategias de manejo y de adaptarse al cambio climĂĄtico. Este estudio investiga la respuesta hidrolĂłgica de la cuenca hidrogrĂĄfica del rĂ­o Aipe (688.9 km2 ), en Huila, Colombia, en acorde con los escenarios de cambio climĂĄtico desde 2011 a 2040. El modelo hidrolĂłgico abcd de Thomas (4 parĂĄmetros) fue calibrado y validado comparando el caudal simulado y lo observado en el punto de cierre de la cuenca (en la estaciĂłn Puente Carretera), usando series histĂłricas mensuales (1992Âż2012). Realizamos la evaluaciĂłn de la sensibilidad e identificabilidad de los parĂĄmetros con la herramienta `Monte Carlo Analysis ToolboxÂż (MCAT). Los resultados muestran que el modelo es capaz de representar adecuadamente los caudales mensuales observados en el punto de desagĂŒe de la cuenca, al encontrarse un Ă­ndice de eficiencia de NashÂżSutcliffe (NSE) de 0,89. Los parĂĄmetros mĂĄs influyentes son a (almacenamiento del agua en el suelo) y c (aporte al acuĂ­fero). Con respecto a la simulaciĂłn de los escenarios, la lĂ­nea base (1992Âż2012) estimĂł un caudal medio de 15,44 m3 s Âż1 ; el escenario de extrapolaciĂłn de tendencias estimĂł un caudal de 13,79 m3 s Âż1 (Âż10,64%); el escenario de ensamble multi-modelo de 9,34 m3 s Âż1 (Âż39,47%) y el escenario A2 de 5,74 m3 s Âż1 (Âż62,60%). Proponemos una baterĂ­a de medidas de adaptaciĂłn al cambio climĂĄtico que buscan la gestiĂłn integral del recurso hĂ­drico.Romero-Cuellar, J.; Buitrago-Vargas, A.; Quintero-Ruiz, T.; FrancĂ©s, F. (2018). SimulaciĂłn hidrolĂłgica de los impactos potenciales del cambio climĂĄtico en la cuenca hidrogrĂĄfica del rĂ­o Aipe, en Huila, Colombia. RIBAGUA - Revista Iberoamericana del Agua. 5(1):63-78. https://doi.org/10.1080/23863781.2018.1454574S63785
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