247 research outputs found

    Lignocellulosic Biomass Utilization Toward Biorefinery Using Meshophilic Clostridial Species

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    Lignocellulosic biomass such as agricultural, industrial, and forestry residues as well asdedicated crops constitute renewable and abundant resources with great potential for a lowcostand uniquely sustainable bioconversion to value-added bioproducts. Thus, manyorganic fuels and chemicals that can be obtained from lignocellulosic biomass can reducegreenhouse gas emissions, enhance energy security, improve the economy, dispose ofproblematic solid wastes, and improve air quality. In particular, liquid biofuels are attractivecandidates, since little or no change is needed to the current petroleum-based fueltechnologies. However, the biorefining process remains economically unfeasible due to alack of biocatalysts that can overcome costly hurdles such as cooling from high temperature,pumping of oxygen/stirring, and, neutralization from acidic or basic pH. Therefore,bioconversion of the lignocellulosic components into fermentable sugars is an essential stepin the biorefinery

    Bioorthogonal uncaging of cytotoxic paclitaxel through Pd nanosheet-hydrogel frameworks

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    The promising potential of bioorthogonal catalysis in biomedicine is inspiring incremental efforts to design strategies that regulate drug activity in living systems. To achieve this, it is not only essential to develop customized inactive prodrugs and biocompatible metal catalysts but also the right physical environment for them to interact and enable drug production under spatial and/or temporal control. Toward this goal, here, we report the first inactive precursor of the potent broad-spectrum anticancer drug paclitaxel (a.k.a. Taxol) that is stable in cell culture and labile to Pd catalysts. This new prodrug is effectively uncaged in cancer cell culture by Pd nanosheets captured within agarose and alginate hydrogels, providing a biodegradable catalytic framework to achieve controlled release of one of the most important chemotherapy drugs in medical practice. The compatibility of bioorthogonal catalysis and physical hydrogels opens up new opportunities to administer and modulate the mobility of transition metal catalysts in living environs

    Oral antibiotic prophylaxis lowers surgical site infection in elective colorectal surgery: results of a pragmatic cohort study in Catalonia

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    Background: The role of oral antibiotic prophylaxis (OAP) and mechanical bowel preparation (MBP) in the prevention of surgical site infection (SSI) after colorectal surgery is still controversial. The aim of this study was to analyze the effect of a bundle including both measures in a National Infection Surveillance Network in Catalonia. Methods: Pragmatic cohort study to assess the effect of OAP and MBP in reducing SSI rate in 65 hospitals, comparing baseline phase (BP: 2007-2015) with implementation phase (IP: 2016-2019). To compare the results, a logistic regression model was established. Results: Out of 34,421 colorectal operations, 5180 had SSIs (15.05%). Overall SSI rate decreased from 18.81% to 11.10% in BP and IP, respectively (OR 0.539, CI95 0.507-0.573, p < 0.0001). Information about bundle implementation was complete in 61.7% of cases. In a univariate analysis, OAP and MBP were independent factors in decreasing overall SSI, with OR 0.555, CI95 0.483-0.638, and OR 0.686, CI95 0.589-0.798, respectively; and similarly, organ/space SSI (O/S-SSI) (OR 0.592, CI95 0.494-0.710, and OR 0.771, CI95 0.630-0.944, respectively). However, only OAP retained its protective effect at both levels at multivariate analyses. Conclusions: oral antibiotic prophylaxis decreased the rates of SSI and O/S-SSI in a large series of elective colorectal surger

    Enhanced stability of perovskite solar cells incorporating dopant-free Crystalline spiro-OMeTAD layers by vacuum sublimation

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    The main handicap still hindering the eventual exploitation of organometal halide perovskite-based solar cells is their poor stability under prolonged illumination, ambient conditions, and increased temperatures. This article shows for the first time the vacuum processing of the most widely used solid-state hole conductor (SSHC), i.e., the Spiro-OMeTAD [2,2′,7,7′-tetrakis (N,N-di-p-methoxyphenyl-amine) 9,9′-spirobifluorene], and how its dopant-free crystalline formation unprecedently improves perovskite solar cell (PSC) stability under continuous illumination by about two orders of magnitude with respect to the solution-processed reference and after annealing in air up to 200 °C. It is demonstrated that the control over the temperature of the samples during the vacuum deposition enhances the crystallinity of the SSHC, obtaining a preferential orientation along the π–π stacking direction. These results may represent a milestone toward the full vacuum processing of hybrid organic halide PSCs as well as light-emitting diodes, with promising impacts on the development of durable devices. The microstructure, purity, and crystallinity of the vacuum sublimated Spiro-OMeTAD layers are fully elucidated by applying an unparalleled set of complementary characterization techniques, including scanning electron microscopy, X-ray diffraction, grazing-incidence small-angle X-ray scattering and grazing-incidence wide-angle X-ray scattering, X-ray photoelectron spectroscopy, and Rutherford backscattering spectroscopy.The authors thank the “Agencia Estatal de Investigación”, “Consejería de Economía y Conocimiento de la Junta de Andalucía” (US‐1263142), “Ministerio de Economía y Competitividad” (MAT2016‐79866‐R, MAT2013‐42900‐P, FPA2016‐77689‐C2‐1‐R, and MAT2016‐76892‐C3‐2‐R) and the European Union (EU) through cohesion fund and FEDER 2014‐2020 programs for financial support. J.R.S.‐V. and A.B. acknowledge the EU project PlasmaPerovSol and funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska‐Curie grant agreement ID 661480. J.R.S.‐V‐ and M.C.L.‐S. thank the University of Seville through the VI “Plan Propio de Investigación y Transferencia de la US” (VI PPIT‐US). This research has received funding from the EU‐H2020 research and innovation programme under Grant Agreement No. 654360 having benefitted from the access provided by Technische Universität Graz at Elettra—TUG in Trieste (IT) within the framework on the NFFA (Nanoscience Foundries & Fine Analysis) Europe Transnational Access Activity. F.J.A. and J.R.S.‐V. acknowledge the “Juan de la Cierva” and “Ramon y Cajal” national programs, respectively

    Investigación en docencia por contenidos (español como segunda lengua) en el proceso de internacionalización de la UA

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    La creciente internacionalización de nuestra universidad, junto con la experiencia acumulada desde la coordinación de programas Erasmus y la docencia a alumnado universitario no nativo, en diversas titulaciones, así como en las cinco ediciones del Curso de español académico para alumnos extranjeros, nos ha permitido constatar la relevancia de la integración académica de los estudiantes internacionales. El objetivo de la red es presentar la percepción del profesorado acerca de su presencia en las clases (cómo ha afectado a su docencia), así como la situación de los propios estudiantes, para averiguar cuáles son los retos a los que ambos colectivos se enfrentan. Nuestros informantes han sido 23 profesores del Dpto. de Filología Española con alumnado internacional y 30 estudiantes de movilidad matriculados en asignaturas ofertadas por dicho departamento, de quienes hemos recabado información a través de cuestionarios que nos han permitido obtener datos estadísticos. Los resultados finales nos indican, entre otros aspectos, la importancia del requisito lingüístico y del conocimiento de las rutinas académicas por parte del alumnado, así como la conveniencia de pautas sobre su evaluación para el profesorado. Se percibe a su vez la necesidad de una futura Guía académica para el alumnado extranjero, que contribuiría a un mejor rendimiento académico de su estancia

    Highly Anisotropic Organometal Halide Perovskite Nanowalls Grown by Glancing-Angle Deposition

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    Polarizers are ubiquitous components in current optoelectronic devices as displays or photographic cameras. Yet, control over light polarization is an unsolved challenge, since the main drawback of the existing display technologies is the significant optical losses. In such a context, organometal halide perovskites (OMHP) can play a decisive role given their flexible synthesis with tunable optical properties such as bandgap and photoluminescence, and excellent light emission with a low non-radiative recombination rate. Therefore, along with their outstanding electrical properties have elevated hybrid perovskites as the material of choice in photovoltaics and optoelectronics. Among the different OMHP nanostructures, nanowires and nanorods have lately arisen as key players in the control of light polarization for lighting or detector applications. Herein, the fabrication of highly aligned and anisotropic methylammonium lead iodide perovskite nanowalls by glancing-angle deposition, which is compatible with most substrates, is presented. Their high alignment degree provides the samples with anisotropic optical properties such as light absorption and photoluminescence. Furthermore, their implementation in photovoltaic devices provides them with a polarization-sensitive response. This facile vacuum-based approach embodies a milestone in the development of last-generation polarization-sensitive perovskite-based optoelectronic devices such as lighting appliances or self-powered photodetectors

    Relapse, cognitive reserve, and their relationship with cognition in first episode schizophrenia: a 3-year follow-up study

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    Schizophrenia is frequently characterized by the presence of multiple relapses. Cognitive impairments are core features of schizophrenia. Cognitive reserve (CR) is the ability of the brain to compensate for damage caused by pathologies such as psychotic illness. As cognition is related to CR, the study of the relationship between relapse, cognition and CR may broaden our understanding of the course of the disease. We aimed to determine whether relapse was associated with cognitive impairment, controlling for the effects of CR. Ninety-nine patients with a remitted first episode of schizophrenia or schizophreniform disorder were administered a set of neuropsychological tests to assess premorbid IQ, attention, processing speed, working memory, verbal and visual memory, executive functions and social cognition. They were followed up for 3 years (n=53) or until they relapsed (n=46). Personal and familial CR was estimated from a principal component analysis of the premorbid information gathered. Linear mixed-effects models were applied to analyse the effect of time and relapse on cognitive function, with CR as covariate. Patients who relapsed and had higher personal CR showed less deterioration in attention, whereas those with higher CR (personal and familial CR) who did not relapse showed better performance in processing speed and visual memory. Taken together, CR seems to ameliorate the negative effects of relapse on attention performance and shows a positive effect on processing speed and visual memory in those patients who did not relapse. Our results add evidence for the protective effect of CR over the course of the illness

    Disruption of the acetate kinase (ack) gene of Clostridium acetobutylicum results in delayed acetate production

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    In microorganisms, the enzyme acetate kinase (AK) catalyses the formation of ATP from ADP by de-phosphorylation of acetyl phosphate into acetic acid. A mutant strain of Clostridium acetobutylicum lacking acetate kinase activity is expected to have reduced acetate and acetone production compared to the wild type. In this work, a C. acetobutylicum mutant strain with a selectively disrupted ack gene, encoding AK, was constructed and genetically and physiologically characterized. The ack− strain showed a reduction in acetate kinase activity of more than 97% compared to the wild type. The fermentation profiles of the ack− and wild-type strain were compared using two different fermentation media, CGM and CM1. The latter contains acetate and has a higher iron and magnesium content than CGM. In general, fermentations by the mutant strain showed a clear shift in the timing of peak acetate production relative to butyrate and had increased acid uptake after the onset of solvent formation. Specifically, in acetate containing CM1 medium, acetate production was reduced by more than 80% compared to the wild type under the same conditions, but both strains produced similar final amounts of solvents. Fermentations in CGM showed similar peak acetate and butyrate levels, but increased acetoin (60%), ethanol (63%) and butanol (16%) production and reduced lactate (−50%) formation by the mutant compared to the wild type. These findings are in agreement with the proposed regulatory function of butyryl phosphate as opposed to acetyl phosphate in the metabolic switch of solventogenic clostridia

    Predicción de color de la pulpa en melones enteros mediante espectroscopía de reflectancia en el infrarrojo cercano

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    El color de la pulpa del melón es uno de los índices utilizados para determinar el grado de madurez y calidad del mismo, siendo necesario disponer de medidas no destructivas que impidan el daño y la depreciación del producto. La tecnología NIRS ofrece enormes expectativas en este terreno, particularmente derivadas de su carácter de no destructiva, rápida y con posibilidad de ser incorporada a nivel de la línea de producción. El objetivo de este trabajo de investigación fue evaluar un instrumento NIRS de red de diodos para estimar el color del mesocarpio (a*: variación verde-rojo y b*: variación amarillo-azul) de melones intactos. El desarrollo de los modelos de predicción de color se realizó utilizando un colectivo constituido por 158 muestras (vars. Cantaloupe y Galia) procedentes de El Ejido (Almería). Los valores del coeficiente de determinación (r2) y del error típico de validación cruzada (ETVC) obtenidos para los parámetros a* (0,97, 1,98) y b* (0,88, 3,17) en la fruta intacta indican la viabilidad inicial del empleo de la tecnología NIRS para la determinación de la madurez y calidad de frutos de melón enteros

    A Precision Treatment Model for Internet-Delivered Cognitive Behavioral Therapy for Anxiety and Depression among University Students:A Secondary Analysis of a Randomized Clinical Trial

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    Importance: Guided internet-delivered cognitive behavioral therapy (i-CBT) is a low-cost way to address high unmet need for anxiety and depression treatment. Scalability could be increased if some patients were helped as much by self-guided i-CBT as guided i-CBT. Objective: To develop an individualized treatment rule using machine learning methods for guided i-CBT vs self-guided i-CBT based on a rich set of baseline predictors. Design, Setting, and Participants: This prespecified secondary analysis of an assessor-blinded, multisite randomized clinical trial of guided i-CBT, self-guided i-CBT, and treatment as usual included students in Colombia and Mexico who were seeking treatment for anxiety (defined as a 7-item Generalized Anxiety Disorder [GAD-7] score of ≥10) and/or depression (defined as a 9-item Patient Health Questionnaire [PHQ-9] score of ≥10). Study recruitment was from March 1 to October 26, 2021. Initial data analysis was conducted from May 23 to October 26, 2022. Interventions: Participants were randomized to a culturally adapted transdiagnostic i-CBT that was guided (n = 445), self-guided (n = 439), or treatment as usual (n = 435). Main Outcomes and Measures: Remission of anxiety (GAD-7 scores of ≤4) and depression (PHQ-9 scores of ≤4) 3 months after baseline. Results: The study included 1319 participants (mean [SD] age, 21.4 [3.2] years; 1038 women [78.7%]; 725 participants [55.0%] came from Mexico). A total of 1210 participants (91.7%) had significantly higher mean (SE) probabilities of joint remission of anxiety and depression with guided i-CBT (51.8% [3.0%]) than with self-guided i-CBT (37.8% [3.0%]; P =.003) or treatment as usual (40.0% [2.7%]; P =.001). The remaining 109 participants (8.3%) had low mean (SE) probabilities of joint remission of anxiety and depression across all groups (guided i-CBT: 24.5% [9.1%]; P =.007; self-guided i-CBT: 25.4% [8.8%]; P =.004; treatment as usual: 31.0% [9.4%]; P =.001). All participants with baseline anxiety had nonsignificantly higher mean (SE) probabilities of anxiety remission with guided i-CBT (62.7% [5.9%]) than the other 2 groups (self-guided i-CBT: 50.2% [6.2%]; P =.14; treatment as usual: 53.0% [6.0%]; P =.25). A total of 841 of 1177 participants (71.5%) with baseline depression had significantly higher mean (SE) probabilities of depression remission with guided i-CBT (61.5% [3.6%]) than the other 2 groups (self-guided i-CBT: 44.3% [3.7%]; P =.001; treatment as usual: 41.8% [3.2%]; P &lt;.001). The other 336 participants (28.5%) with baseline depression had nonsignificantly higher mean (SE) probabilities of depression remission with self-guided i-CBT (54.4% [6.0%]) than guided i-CBT (39.8% [5.4%]; P =.07). Conclusions and Relevance: Guided i-CBT yielded the highest probabilities of remission of anxiety and depression for most participants; however, these differences were nonsignificant for anxiety. Some participants had the highest probabilities of remission of depression with self-guided i-CBT. Information about this variation could be used to optimize allocation of guided and self-guided i-CBT in resource-constrained settings. Trial Registration: ClinicalTrials.gov Identifier: NCT04780542.</p
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