32 research outputs found

    Tren de palabras - La escritura de Fernando del Paso

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    Tren de palabras. La escritura de Fernando del Paso recoge seis ensayos y una entrevista a cargo de cuatro estudiosos de la obra delpasiana; el sello es alumbrar nuevas perspectivas, encarar las omisiones y acrecentar el diálogo, bien argumentado, que abone a una comprensión mejor de esta abrumadora y desbordante literatura, ínsula en sí misma.Universidad Autónoma del Estado de México, UAEM

    Enzymatic synthesis and characterization of different families of chitooligosaccharides and their bioactive properties

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    Chitooligosaccharides (COS) are homo- or hetero-oligomers of D-glucosamine (GlcN) and N-acetyl-D-glucosamine (GlcNAc) that can be obtained by chitosan or chitin hydrolysis. Their enzymatic production is preferred over other methodologies (physical, chemical, etc.) due to the mild conditions required, the fewer amounts of waste and its efficiency to control product composition. By properly selecting the enzyme (chitinase, chitosanase or nonspecific enzymes) and the substrate properties (degree of deacetylation, molecular weight, etc.), it is possible to direct the synthesis towards any of the three COS types: fully acetylated (faCOS), partially acetylated (paCOS) and fully deacetylated (fdCOS). In this article, we review the main strategies to steer the COS production towards a specific group. The chemical characterization of COS by advanced techniques, e.g., high-performance anion-exchange chromatography with pulsed amperometric detection (HPAECPAD) and MALDI-TOF mass spectrometry, is critical for structure-function studies. The scaling of processes to synthesize specific COS mixtures is difficult due to the low solubility of chitin/chitosan, the heterogeneity of the reaction mixtures, and high amounts of salts. Enzyme immobilization can help to minimize such hurdles. The main bioactive properties of COS are herein reviewed. Finally, the anti-inflammatory activity of three COS mixtures was assayed in murine macrophages after stimulation with lipopolysaccharidesThis work was supported by grants from the EU EMFF-Blue Economy-2018 (FISH4FISH- 863697 project), the Spanish Ministry of Economy and Competitiveness (Grants BIO2016-76601- C3-1,2-R), the Spanish Ministry of Science and Innovation (Grants PID2019-105838RB-C31/C32), Fundación Ramón Areces (XIX Call of Research Grants in Life and Material Sciences) and by an institutional grant from Fundación Ramón Areces to the Centro de Biología Molecula

    Reuse of immobilized komagataella phaffii cells for the elimination of d -glucose in syrups of bioactive carbohydrates

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    During the synthesis of prebiotic carbohydrates such as fructooligosaccharides (FOS), galactooligosaccharides (GOS), or isomaltooligosaccharides (IMOS), d-glucose is released as a side-product of the transglycosylation process. It is desirable to remove glucose from these sugar mixtures due to its caloric contribution and its effect on caries and diabetes. In this work, we have investigated the use of immobilized Komagataella phaffii (formerly Pichia pastoris) for elimination of d-glucose and d-fructose in several sugar syrups. K. phaffii cells were immobilized in calcium alginate beads to facilitate the separation of the yeast cells from the reaction medium and reuse of the biocatalyst. The immobilized yeasts were successfully reutilized for at least 20 cycles (of 195 min) to remove d-glucose (62.3 g/L) and d-fructose (5.5 g/L) in a FOS syrup, without affecting the concentration of oligosaccharides. Excellent selectivity was also found for elimination of d-glucose (57.2 g/L) in IMOS syrups. The methodology is versatile and easy to scale-up, as demonstrated in the removal of d-glucose (97.5 g/L) and d-fructose (142 g/L) for the purification of heteroglucooligosaccharides synthesized by Metschnikowia reukaufii α-glucosidase. In addition, d-glucose (50 g/L) was selectively removed by K. phaffii beads in the presence of d-galactose (50 g/L) for at least 20 cycles of 150 min and applied to GOS purificationWe thank Grants PID2019-105838RB-C31 and PID2019-105838RB-C32 funded by MCIN/AEI/10.13039/50110001103

    Evaluating the impact of culture conditions on human mesenchymal stem/stromal cell-derived exosomes through FTIR spectroscopy

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    In the last decade, the therapeutic effects of mesenchymal stem/stromal cells (MSCs) have been attributed to a paracrine activity exerted by extracellular vesicles secreted by MSCs, as exosomes. Their properties as intercellular communication vehicles have led to an increase interest in their use for cell-free therapeutic applications. The present work aimed to evaluate how different culture conditions, as culture medium (xenogeneic -free (XF) vs serum-containing medium), conditioning time (1, 2 and 3 days) and different MSC donors (n=6), affect the chemical characteristics of exosomes. For that, purified MSC-derived exosomes were characterized by Fourier-Transform InfraRed (FTIR) spectroscopy, a highly sensitive, fast and high throughput technique. The principal component analysis (PCA) of pre-processed FTIR spectra of purified exosomes was conducted, enabling the evaluation of the replica variance of the exosomes chemical fingerprint in a reduced dimensionality space. For that, different pre-processing methods were studied as baseline correction, standard normal variation and first and second derivative. It was observed that the chemical fingerprint of exosomes is more dependent of the medium used for MSCs cultivation than the MSC donor and conditioning days. Exosomes secreted by MSCs cultured with serum-containing medium presented a more homogenous chemical fingerprint than exosomes obtained with XF medium. Moreover, for a given medium (XF or serum-containing medium), the exosomes chemical fingerprint depends more of the MSC donor than of the conditioning days. The regression vector of the PCA enabled to identified relevant spectral bands that enabled the separation of samples in the score-plot of the previous analysis. Ratios between these spectral bands were determined, since these attenuate artifacts due to cell quantity and baseline distortions underneath each band. Statistically inference analysis of the ratios of spectral bands were conducted, by comparing the equality of the means of the populations using appropriate hypothesis tests and considering the significance level of 5%. It was possible to define ratios of spectral bands, that can be used as biomarkers, enabling the discrimination of exosomes chemical fingerprint in function of the medium used for MSC grown and the MSC donor. This work is therefore a step forward into understanding how different culture conditions and MSC donors affect MSC exosomes characteristics

    Efficacy and safety of autologous platelet rich plasma for the treatment of vascular ulcers in primary care: Phase III study

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    Background: Vascular ulcers are commonly seen in daily practice at all levels of care and have great impact at personal, professional and social levels with a high cost in terms of human and material resources. Given that the application of autologous platelet rich plasma has been shown to decrease healing times in various different studies in the hospital setting, we considered that it would be interesting to assess the efficacy and feasibility of this treatment in primary care. The objectives of this study are to assess the potential efficacy and safety of autologous platelet rich plasma for the treatment of venous ulcers compared to the conventional treatment (moist wound care) in primary care patients with chronic venous insufficiency (C, clinical class, E, aetiology, A, anatomy and P, pathophysiology classification C6). Design: We will conduct a phase III, open-label, parallel-group, multicentre, randomized study. The subjects will be 150 patients aged between 40 and 100 years of age with an at least 2-month history of a vascular venous ulcer assigned to ten primary care centres. For the treatment with autologous platelet rich plasma, all the following tasks will be performed in the primary care setting: blood collection, centrifugation, separation of platelet rich plasma, activation of coagulation adding calcium chloride and application of the PRP topically after gelification. The control group will receive standard moist wound care. The outcome variables to be measured at baseline, and at weeks 5 and 9 later include: reduction in the ulcer area, Chronic Venous Insufficiency Quality of Life Questionnaire score, and percentage of patients who require wound care only once a week. Discussion: The results of this study will be useful to improve the protocol for using platelet rich plasma in chronic vascular ulcers and to favour wider use of this treatment in primary care.This study can be undertaken thanks to the financial support of the Spanish Carlos III Health Institute. We are grateful for funding from the Department of Health and Consumer Affairs of the Government of the Basque Country, the Basque Health Service (Osakidetza) for the pilot support and the Ezkerraldea Enkarterri health region

    Pervasive gaps in Amazonian ecological research

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    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

    Pervasive gaps in Amazonian ecological research

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    Pervasive gaps in Amazonian ecological research

    Get PDF
    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

    Pervasive gaps in Amazonian ecological research

    Get PDF
    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

    Interpretación jurídica, toma de decisiones y la neurociencia: el papel de la cognición y la emoción en el razonamiento jurídico

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    [spa] La localización de los correlatos cerebrales relacionados con el juicio moral, tanto usando técnicas de neuroimagen como por medio de los estudios sobre lesiones cerebrales, parece ser, sin duda, una de las grandes noticias de la historia de las ciencias sociales normativas. De hecho, en la medida en que la neurociencia permite un entendimiento cada vez más sofisticado del cerebro, las posibles implicaciones morales, legales y sociales resultantes de la investigación neurobiológica de nuestra concepción moral, de nuestro conocimiento del bien y dem mal, empiezan a poder ser considerados bajo una óptica mucho más empírica y respetuosa con los métodos científicos. En filosofía, una de las cuestiones que más se ha discutido es la de si los juicios morales tienen como causa primordial las emociones o la razón. Las respuestas que dieron Hume y Kant a tal pregunta han servido como punto de partida de dos de las doctrinas filosóficas más destacadas al respecto: el emotivismo y el racionalismo. Estas corrientes, aún en nuestros días, permean la discusión sobre la naturaleza de los juicios morales. El mejor modelo neurocientífico del juicio normativo disponible hoy establece que el operador del derecho cuenta, en sus sistemas evaluativo-afectivos neuronales, con una permanente presencia de las exigencias, obligaciones y estrategias, con un “deber-ser” que incorpora de forma interna razones y emociones y que se integra constitutivamente en las actividades de los niveles práctico, teórico y normativo de todo proceso de realización del derecho
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