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Enhancement of Thermal–Acoustic Properties of Pinus radiata by Impregnation of Bio-Phase-Change Materials
No full textCOSMO-RS-based solvent screening and experimental analysis for recovering added-value chemicals from the bio-oil aqueous phase
No full textBio-oil's aqueous phase (BAP) has received particular interest for recovering value-added chemicals. To this end, liquid-liquid extraction (LLE) has proven its suitability for bio-oil fractionation and product recovery. The present work aimed to assess greener solvents (e.g., bio-based and terpene-based) for recovering acetic acid and acetol as model compounds of the BAP via physical and reactive LLE. A solvent screening (>2000 compounds) based on the distribution coefficient (K-d) of each solute in the solvent/water biphasic system estimated by COSMO-RS was used. Then, the solvents' environmental, safety, and human health impacts were assessed. The selected candidates were used to validate the COSMO-RS predictions through LLE measurements. In the reactive LLE, the selected extracting solvents were mixed with trioctylamine (TOA) or tributyl phosphate (TBP) used as the reactive extractants. Finally, the temperature and extractant fraction effects were assessed in terms of the K-d for the best diluent + extractant pairs. For acetic acid, 2-methyltetrahydrofuran (K-d = 1.8) outperformed the rest of the solvents during the physical extraction, whereas for acetol, 2-methyl-2-butanol (K-d = 0.44) was the solvent with the best performance. Moreover, attractive K-d values were obtained for acetic acid (K-d = 0.91) and acetol (K-d = 0.37) using 2-phenylethanol. In the reactive LLE, TOA-based extractants improved the acetic acid K-d up to 10 times compared to the physical extraction, with no improvement on acetol. For TBP-based extractants, no clear improvements were observed. Acetic acid selectivity was maximized at 293 K, and a TOA mass fraction between 40 and 50 % for all the diluents
End-to-end deep learning-based motion correction and reconstruction for accelerated whole-heart joint T 1/T 2 mapping.
No full textPURPOSE: To accelerate 3D whole-heart joint T 1/T 2 mapping for myocardial tissue characterization using an end-to-end deep learning algorithm for joint motion estimation and model-based motion-corrected reconstruction of multi-contrast undersampled data.METHODS: A free-breathing high-resolution motion-compensated 3D joint T 1/T 2 water/fat sequence is employed. The sequence consists of the acquisition of four interleaved volumes with 2-echo encoding, resulting in eight volumes with different contrasts. An end-to-end non-rigid motion-corrected reconstruction network is used to estimate high quality motion-corrected reconstructions from the eight multi-contrast undersampled data for subsequent joint T 1/T 2 mapping. Reconstruction with the proposed approach was compared against state-of-the-art motion-corrected HD-PROST reconstruction.RESULTS: The proposed approach yields images with good visual agreement compared to the reference reconstructions. The comparison of the quantitative values in the T 1 and T 2 maps showed the absence of systematic errors, and a small bias of -6.35 ms and -1.8 ms, respectively. The proposed reconstruction time was 24 seconds in comparison to 2.5 hours with motion-corrected HD-PROST, resulting in a reconstruction speed-up of over 370 times.CONCLUSION: In conclusion, this study presents a promising method for efficient whole-heart myocardial tissue characterization. Specifically, the research highlights the potential of the multi-contrast end-to-end deep learning algorithm for joint motion estimation and model-based motion-corrected reconstruction of multi-contrast undersampled data. The findings underscore its ability to compute T 1 and T 2 values with good agreement when compared to the reference motion-corrected HD-PROST method, while substantially reducing reconstruction time
Evaluación de la implementación del Reglamento Sanitario Internacional en la vigilancia de fronteras para la prevención, control de epidemias y brotes en Latinoamérica y El Caribe: un análisis descriptivo
No full textTesis (Magíster en Salud Pública)--Pontificia Universidad Católica de Chile, 2024Este estudio ecológico descriptivo analiza la implementación del Reglamento Sanitario Internacional (RSI) en Latinoamérica y el Caribe, utilizando los puntajes del State Party Self Assessment Annual Reporting (SPAR). Su objetivo es evaluar la capacidad de los países para responder a emergencias sanitarias, identificando fortalezas y debilidades clave. Los datos del SPAR clasifican las capacidades en tres niveles: insuficientes (rojo: 0-20), moderadas (amarillo: 21-60) y adecuadas (verde: 61-100). Se emplearon técnicas estadísticas descriptivas para comparar los puntajes entre países y detectar áreas críticas de mejora. Los resultados muestran una amplia variabilidad en la implementación del RSI, con algunos países destacando en gestión de emergencias y vigilancia, mientras que otros presentan deficiencias en coordinación multisectorial e igualdad de género en emergencias sanitarias. El estudio enfatiza la necesidad de fortalecer bioseguridad, gestión de emergencias y equidad de género a través de mayor financiación y capacitación. Asimismo, resalta la importancia de continuar con evaluaciones externas y cooperación internacional para mejorar la preparación regional ante crisis sanitarias. Esta investigación proporciona evidencia valiosa para reforzar la seguridad sanitaria en la región y garantizar respuestas más efectivas y equitativas ante futuras emergencias.2025-03-1
¿Cuántas ollas comunes funcionaron en Chile durante el COVID-19?
No full textEste estudio concluye que, en Chile, las ollas comunes actúan como una “infraestructura desde abajo”, activada en tiempos de crisis, beneficiando a una cantidad significativa de personas, sin coordinación, ni apoyo oficial. A modo de sugerencia, las políticas públicas para la resiliencia deben integrar la organización de ollas comunes para enfrentar la inseguridad alimentaria, aprovechando su capacidad de movilizar recursos y prestar servicios solidarios a nivel de comunidad
Ruinas, descampados y fábricas: miradas sobre la ciudad en tres novelas de Sergio Chejfec
No full textTesis (Magíster en Literatura)--Pontificia Universidad Católica de Chile, 2025En el presente estudio analizaremos la representación del paisaje urbano en tres novelas del escritor argentino Sergio Chejfec. Estas serán Boca de lobo (2000), La experiencia dramática (2012) y 5 (2019). Si bien nuestro foco de estudio estará puesto en el espacio representado, este cobrará relevancia al ser un medio para acceder a la mirada de los personajes que lo habitan, con lo que podremos interpretar sus subjetividades e interioridades, e identificar cómo se entienden ellos mismos y cómo perciben su lugar en el mundo
Innovation Meets Practice: A Scalable Simulation-based Methodology for Massive Paracentesis Training
No full textFONDECYT; Folios: 1221490; 1230504FONIS; Folio: SA19-0188FONDAP; Folio: 152220002European Union’s Horizon 2020 Research and Innovation Program Grant
Agreement; Folio: 82583
Exploring catalytic activity modulations: photoredox catalysis with substituted copper(i)-dipyridylamine derivatives
No full textIn this work, we have successfully synthesized five new heteroleptic copper(i) complexes (C1-5), bearing N,N ligands derived from dipyridylamine and S-BINAP as the P,P auxiliary ligand. All complexes were structurally characterized using NMR, FT-IR, and elemental analysis. Furthermore, the molecular structures of C1, C4, and C5 were determined via X-ray diffraction analysis. The photophysical properties of all complexes were assessed using UV-Vis spectroscopy and spectrofluorometric measurements in dichloromethane solution and the solid state. All complexes displayed absorption bands at lower energies, attributed to spin-allowed MLCT transitions. In degassed dichloromethane solution at room temperature, all complexes exhibited broad luminescence in the visible spectrum, mainly assigned to MLCT/LLCT phosphorescence, with excited state lifetimes in the μs time regime. Besides, all complexes were assessed as photoredox catalysts in chlorosulfonylation and bromonitromethylation reactions of styrene, showing remarkable performances, thus highlighting the privileged role of the dpa ligand for the design of Earth-abundant metal photocatalysts.Italian MURFondecytUniversità degli Studi di Ferrar
Volatile organic compounds produced after exposure of tomato roots to the soil yeast Solicoccozyma terrea modulate root nitrate transporters in tomato
No full textBackground Beneficial microorganisms modify root architecture through different mechanisms mostly related to plant hormones synthesis. Less information is available regarding the emission of microbial volatile organic compounds (VOCs) and their effects on root architecture. Numerous studies describe the release of VOCs by bacteria and filamentous fungi, but little information is available regarding soil yeasts.MethodsThe VOCs released by the soil yeast Solicoccozyma terrea were evaluated in an experiment with tomato seedlings. Four treatments (tomato seedlings, T; S. terrea inoculum without tomato seedlings, St; tomato seedlings exposed to the volatiles of S. terrea inoculum, TSt; and a control without tomato seedlings or yeast inoculum, C) were assessed in terms of root morphology. VOCs were analyzed by GC-MS, and in a second experiment, the response of tomato seedlings and root nitrate uptake transporters to specific compounds identified in the first experiment was evaluated under low and high N supply.ResultsA mixture with 57 VOCs was identified which promoted lateral roots formation in tomato plants. Three compounds (isopropyl alcohol, 2-pentylfuran and trans-1,3-pentadiene) were exclusively present in the TSt treatment. All three compounds stimulated lateral roots formation and increased root volume. These compounds showed a stimulatory effect on the expression of NRT1.2, NRT2.1 and NRT2.3 nitrate transporters under N deficiency conditions.ConclusionsThis study provides, for the first time, information on a soil yeast capable of promoting lateral roots formation in tomato through VOCs and that isopropyl alcohol, 2-pentylfuran and trans-1,3-pentadiene modulate root nitrate transporters expression under N deficiency conditions
Baseline body fat percentage is associated to weight and fat mass gain from high-fat overfeeding over 8 weeks
No full textBackground & aims: Epidemiological data suggest that participants with lower vs. higher body mass index (BMI) resist exposure to the obesogenic environment. To test this, we analyzed the relationship between overfeeding-induced weight and fat mass gains with baseline BMI and body fat percentage.Methods: In this controlled intervention study, 34 men (age: 26±5 y old; BMI: 25.5±2.4 kg/m2, body fat [DXA]: 19.3±5.1%) consumed for 8 weeks 40% more energy than needed at weight maintenance. The energy costs of weight and fat mass gain were calculated as the 8-week excess energy consumed divided by weight or fat mass gain. Energy expenditure (baseline and after overfeeding) was determined using a metabolic chamber and doubly labeled water. Transcriptomic analysis was conducted from abdominal subcutaneous adipose tissue samples.Results: Body weight increased 7.2±2.1 kg and fat mass 4.0±1.4 kg. There was no statistical association between baseline BMI and weight and fat mass gains. However, baseline body fat percentage was significantly associated with weight (r=0.57) and fat mass (r=0.59) gains. Body fat percentage was also statistically associated with energy cost of weight (r=-0.38) and fat mass (r=-0.40) gains. Metabolic adaptation in energy expenditure (adaptive thermogenesis) was unrelated to the energy cost of weight and fat mass gains. Transcriptomics analysis showed that high energy cost of weight gain was associated with up-regulation of inflammation-related pathways.Conclusion: Body fat percentage at baseline was inversely associated with overfeeding-induced weight and fat gain resistance. The underlying compensatory response appears unrelated to changes in energy expenditur