1,335 research outputs found

    Study of the effect of the dispersion of functionalized nanoparticles TiO2 with photocatalytic activity in LDPE

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    "A photodegradable Low Density Polyethylene-Titanium dioxide (LDPE-TiO2) nanocomposite film was prepared, and its evaluation considers the partial modification of the surface of the particle using Hexadecyltrimethoxysilane (HDTS) as functionalizing agent under Ultraviolet (UV) radiation. Reaction efficiency of the nanoparticles was evaluated with Thermogravimetric (TGA) and infrared analysis (FT-IR). Nanocomposites were prepared by a melt blending technique; using a twin-screw extruder, each nanocomposite film was thermoformed into different shapes for further evaluation. Scanning Electron Microscopy (SEM) was utilized to determine the size and distribution of nanoparticles in the polymer. Experimental results indicate that surface modification increases the degree of dispersion while decreasing the particle size, enhancing the particle's compatibility with the polymer matrix. Photocatalytic degradation was assessed through accelerated degradation weathering in a chamber under UV radiation to assess the performance of photocatalytic degradation. These tests indicated, that the particle's homogeneity of dispersion and size reduction by functionalization allows for homogeneously degraded surfaces (SEM) to generated a greater abundance of oxidized groups in the sample compared with unfunctionalized sample.

    Seafood in Mediterranean countries: A culinary journey through history

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    Olives, wheat and grapes have been the staple foods of the Mediterranean world, with seafood, above meat, as the preferred protein source. Fish and shellfish were used often since ancient times by wealthy classes as a kind of social marker, not only as a gastronomic delight, but also as a way to stay healthier. This paper reviews thoroughly how seafood has been present in the dietary practices of the Mediterranean people since ancient Egyptians up to the gastronomic discourse of some celebrated contemporary chefs. Preferences for particular tastes and flavors, local traditions, myths and religious rites (such Lent, Shabbat and Ramadan that prohibited eating some foods and allowed others) as well as cultural exchanges between countries and civilizations (with the incorporation of new ingredients and culinary techniques), have shaped the Mediterranean culinary customs along the history. Such traditions are reflected in many ancient writings, culinary literature and cookbooks. We will analyze some of these sources with special attention to those excerpts, anecdotes, cookbooks, recipes, cooks and even characters related to seafood. Knowledge and learning from our rich Mediterranean culinary heritage are important aspects to bear in mind. Whereas some contemporary celebrity chefs (and probably many diners) are not fully aware of such culinary legacy, others like Ferran Adri`a have recently recognized the importance of studying the past as a driver for creation and gastronomic innovation

    Análisis de áreas de actividad en sociedades cazadoras-recolectaras: el caso del abrigo de Santa Marta

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    As análises realizadas mediante Sistemas de Informação Geográfica (SIG), complementadas por estudos químicos dos pisos, análises da distribuição de artefatos e a criação de fotoplanos, permitem a avaliação de áreas de atividade em sociedades de caçadores-coletores. Esses estudos podem ser complementados com análises de microresíduos e traços de uso mediante microscópios metalográficos e microscópio eletrônico (MEB) com a finalidade de avaliar melhor a funcionalidade dos artefatos associados a áreas específicas. O propósito dessas análises é uma perspectiva multidisciplinar no estudo da vida cotidiana das sociedades pré-cerâmicas, e aqui são apresentados os resultados do abrigo Santa Marta, Chiapas, México, como estudo de casoThe analysis through Geographic Information Systems (GIS), supplemented by chemical studies of living floors, analysis of the distribution artifacts and the creation of photoplanes allows the evaluation of activity areas in huntergatherers societies These studies can be complemented with analysis of micro debris and traces of use through metallographic microscopy and electron microscopy (SEM) in order to a better evaluation about the functionality of the artifacts associated with specific areas. The aim of this analysis is a multidisciplinary approach on the study of the everyday life of preceramic societies and here we present the results of Santa Marta Rockshelter in Mexico as a case stud

    Improvement of Remote Sensing-Based Assessment of Defoliation of Pinus spp. Caused by Thaumetopoea pityocampa Denis and Schiffermüller and Related Environmental Drivers in Southeastern Spain

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    This study used Landsat temporal series to describe defoliation levels due to the Pine Processionary Moth (PPM) in Pinus forests of southeastern Andalusia (Spain), utilizing Google Earth Engine. A combination of remotely sensed data and field survey data was used to detect the defoliation levels of different Pinus spp. and the main environmental drivers of the defoliation due to the PPM. Four vegetation indexes were also calculated for remote sensing defoliation assessment, both inside the stand and in a 60-m buffer area. In the area of study, all Pinus species are affected by defoliation due to the PPM, with a cyclic behavior that has been increasing in frequency in recent years. Defoliation levels were practically equal for all species, with a high increase in defoliation levels 2 and 3 since 2014. The Moisture Stress Index (MSI) and Normalized Difference Infrared Index (NDII) exhibited similar overall (p < 0.001) accuracy in the assessment of defoliation due to the PPM. The synchronization of NDII-defoliation data had a similar pattern for all together and individual Pinus species, showing the ability of this index to adjust the model parameters based on the characteristics of specific defoliation levels. Using Landsat-based NDII-defoliation maps and interpolated environmental data, we have shown that the PPM defoliation in southeastern Spain is driven by the minimum temperature in February and the precipitation in June, March, September, and October. Therefore, the NDII-defoliation assessment seems to be a general index that can be applied to forests in other areas. The trends of NDII-defoliation related to environmental variables showed the importance of summer drought stress in the expansion of the PPM on Mediterranean Pinus species. Our results confirm the potential of Landsat time-series data in the assessment of PPM defoliation and the spatiotemporal patterns of the PPM; hence, these data are a powerful tool that can be used to develop a fully operational system for the monitoring of insect damage

    Bacteria-instructed B cells cross-prime naïve CD8+ T cells triggering effective cytotoxic responses.

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    In addition to triggering humoral responses, conventional B cells have been described in vitro to cross-present exogenous antigens activating naïve CD8+ T cells. Nevertheless, the way B cells capture these exogenous antigens and the physiological roles of B cell-mediated cross-presentation remain poorly explored. Here, we show that B cells capture bacteria by trans-phagocytosis from previously infected dendritic cells (DC) when they are in close contact. Bacterial encounter "instructs" the B cells to acquire antigen cross-presentation abilities, in a process that involves autophagy. Bacteria-instructed B cells, henceforth referred to as BacB cells, rapidly degrade phagocytosed bacteria, process bacterial antigens and cross-prime naïve CD8+ T cells which differentiate into specific cytotoxic cells that efficiently control bacterial infections. Moreover, a proof-of-concept experiment shows that BacB cells that have captured bacteria expressing tumor antigens could be useful as novel cellular immunotherapies against cancer.We are grateful to advanced light microscopy and cytometry facilities of CNB for technical supporting. The research is supported by grants: SAF2017-84091- R, and PID2020-116393RB-I00/AEI/10.13039/501100011033, financed by MCIN, BFERO2020.04, financed by FERO foundation and PI20/0036 from ISCIII. RGF is supported by BES-2016-076526 from the Spanish Ministry of Economy Industry and Competitiveness, JOP is supported by fellowship LCF/BQ/SO16/ 52270012 from La Caixa, BHF is supported by FPU18/00895 and AMP by FPU18/03199 from Ministry of Science, Innovation and Universities. LdC has been supported by Juan de la Cierva grant IJC2018-035386-I and a contract associated to SEV-2017-0712. EVC, AMP, AMAM, and NMM belong to the Spanish National Research Council (CSIC)’s Cancer Hub. Synopsis image made with biorender.com by Eduardo Roman Camacho and Esteban Veiga. We thanks Prof. Dan Portnoy who kindly provided bacterial strains.S

    Concurrent validity of supraclavicular skin temperature measured with iButtons and infrared thermography as a surrogate marker of brown adipose tissue

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    We are grateful to Ms. Carmen Sainz-Quinn for assistance with the English language. We are grateful to Alberto Quesada-Aranda for helping with the development of the Temperatus software (Free trial in http://profth.ugr.es/temperatus).This study is part of a Ph.D. Thesis conducted in the Biomedicine Doctoral Studies of the University of Granada, Spain.Brown adipose tissue (BAT) thermogenic activity is commonly assessed with a positron emission tomography with computed tomography scan (PET/CT). This technique has several limitations and alternative techniques are needed. Supraclavicular skin temperature measured with iButtons and infrared thermography (IRT) has been proposed as an indirect marker of BAT activity. We studied the concurrent validity of skin temperature measured with iButtons vs. IRT and the association of supraclavicular skin temperature measured with iButtons and IRT with BAT. We measured skin temperature upon a shivering threshold test with iButtons and IRT in 6 different regions in 12 participants (n = 2 men). On a separate day, we determined supraclavicular skin temperature with an iButton and IRT after 2 h of a personalized cooling protocol. Thereafter, we quantified BAT volume and activity by PET/CT. We observed that the absolute differences between the devices were statistically different from 0 (all P < 0.05) after the shivering threshold test. Moreover, we did not find any association between supraclavicular skin temperature measured with iButtons or IRT and BAT 18F-FDG activity (r = −0.213; P = 0.530 and r = −0.079; P = 0.817). However, we observed a negative association of supraclavicular skin temperature measured by IRT with BAT 18F-FDG volume (r = −0.764; P = 0.006), but not with supraclavicular skin temperature measured with iButtons (r = −0.546; P = 0.082). In light of these results, we concluded that the measurement of skin temperature obtained by iButtons and IRT are not comparable. Furthermore, it seems that supraclavicular skin temperature is not associated with BAT 18F-FDG activity, but it appears to be negatively associated with BAT 18F-FDG volume in the case of IRT.This study was supported by the Spanish Ministry of Economy and Competitiveness via the Fondo de Investigación Sanitaria del Instituto de Salud Carlos III (PI13/01393), Retos de la Sociedad (DEP2016-79512-R), PTA 12264-I, and European Regional Development Fund (ERDF), the Spanish Ministry of Education (FPU 13/04365, FPU14/04172, FPU15/05337, and FPU15/04059), by the Spanish Ministry of Science and Innovation-MINECO (RYC-2014-16938), the Fundación Iberoamericana de Nutrición (FINUT), the Redes Temáticas de Investigación Cooperativa RETIC (Red SAMID RD16/0022), the AstraZeneca HealthCare Foundation, the University of Granada Plan Propio de Investigación 2016 -Excellence actions: Unit of Excellence on Exercise and Health (UCEES) - and Plan Propio de Investigación 2018 - Programa Contratos-Puente, and the Junta de Andalucía, Consejería de Conocimiento, Investigación y Universidades (ERDF, ref. SOMM17/6107/UGR). This study is part of a Ph.D

    Delineation of intracavitary electrograms for the automatic quantification of decrement-evoked potentials in the coronary sinus with deep-learning techniques

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    Cardiac arrhythmias cause depolarization waves to conduct unevenly on the myocardial surface, potentially delaying local components with respect to a previous beat when stimulated at faster frequencies. Despite the diagnostic value of localizing the distinct local electrocardiogram (EGM) components for identifying regions with decrement-evoked potentials (DEEPs), current software solutions do not perform automatic signal quantification. Electrophysiologists must manually measure distances on the EGM signals to assess the existence of DEEPs during pacing or extra-stimuli protocols. In this work, we present a deep learning (DL)-based algorithm to identify decrement in atrial components (measured in the coronary sinus) with respect to their ventricular counterparts from EGM signals, for disambiguating between accessory pathways (APs) and atrioventricular re-entrant tachycardias (AVRTs). Several U-Net and W-Net neural networks with different configurations were trained on a private dataset of signals from the coronary sinus (312 EGM recordings from 77 patients who underwent AP or AVRT ablation). A second, separate dataset was annotated for clinical validation, with clinical labels associated to EGM fragments in which decremental conduction was elucidated. To alleviate data scarcity, a synthetic data augmentation method was developed for generating EGM recordings. Moreover, two novel loss functions were developed to minimize false negatives and delineation errors. Finally, the addition of self-attention mechanisms and their effect on model performance was explored. The best performing model was a W-Net model with 6 levels, optimized solely with the Dice loss. The model obtained precisions of 91.28%, 77.78% and of 100.0%, and recalls of 94.86%, 95.25% and 100.0% for localizing local field, far field activations, and extra-stimuli, respectively. The clinical validation model demonstrated good overall agreement with respect to the evaluation of decremental properties. When compared to the criteria of electrophysiologists, the automatic exclusion step reached a sensitivity of 87.06% and a specificity of 97.03%. Out of the non-excluded signals, a sensitivity of 96.77% and a specificity of 95.24% was obtained for classifying them into decremental and non-decremental potentials. Current results show great promise while being, to the best of our knowledge, the first tool in the literature allowing the delineation of all local components present in an EGM recording. This is of capital importance at advancing processing for cardiac electrophysiological procedures and reducing intervention times, as many diagnosis procedures are performed by comparing segments or late potentials in subsequent cardiac cycles

    Phage-Derived and Aberrant HaloTag Peptides Immobilized on Magnetic Microbeads for Amperometric Biosensing of Serum Autoantibodies and Alzheimer's Disease Diagnosis

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    An electrochemical biosensing platform for serum autoantibodies (AAbs) detection is reported in this work, exploiting for the first time six Alzheimer's disease (AD)-specific phage-derived and frameshift aberrant HaloTag peptides as receptors, immobilized on magnetic microbeads (MBs) surface and captured on disposable electrodes to perform amperometric detection. Operational analytical characteristics and clinical diagnostic ability of the bioplatform were probed in optimized key experimental conditions by analysing serum AAbs of AD patients and healthy subjects. The value of 100% obtained for AUC, sensitivity, and selectivity from the all peptides combined ROC curve, indicate full AD-diagnostic capability of the methodology, which was further implemented, as proof of concept, in a POC multiplexing platform to detect the signature in a single test over clinically actionable times (1 h 15 min), opening great promise for the type of diagnosis and AD patients’ monitoring follow-up currently pursued
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