Myristic acid potentiates palmitic acid-induced lipotoxicity and steatohepatitis associated with lipodystrophy by sustaning de novo ceramide synthesis.

Palmitic acid (PA) induces hepatocyte apoptosis and fuels de novo ceramide synthesis in the endoplasmic reticulum (ER). Myristic acid (MA), a free fatty acid highly abundant in copra/palmist oils, is a predictor of nonalcoholic steatohepatitis (NASH) and stimulates ceramide synthesis. Here we investigated the synergism between MA and PA in ceramide synthesis, ER stress, lipotoxicity and NASH. Unlike PA, MA is not lipotoxic but potentiated PA-mediated lipoapoptosis, ER stress, caspase-3 activation and cytochrome c release in primary mouse hepatocytes (PMH). Moreover, MA kinetically sustained PA-induced total ceramide content by stimulating dehydroceramide desaturase and switched the ceramide profile from decreased to increased ceramide 14:0/ceramide16:0, without changing medium and long-chain ceramide species. PMH were more sensitive to equimolar ceramide14:0/ceramide16:0 exposure, which mimics the outcome of PA plus MA treatment on ceramide homeostasis, than to either ceramide alone. Treatment with myriocin to inhibit ceramide synthesis and tauroursodeoxycholic acid to prevent ER stress ameliorated PA plus MA induced apoptosis, similar to the protection afforded by the antioxidant BHA, the pan-caspase inhibitor z-VAD-Fmk and JNK inhibition. Moreover, ruthenium red protected PMH against PA and MA-induced cell death. Recapitulating in vitro findings, mice fed a diet enriched in PA plus MA exhibited lipodystrophy, hepatosplenomegaly, increased liver ceramide content and cholesterol levels, ER stress, liver damage, inflammation and fibrosis compared to mice fed diets enriched in PA or MA alone. The deleterious effects of PA plus MA-enriched diet were largely prevented by in vivo myriocin treatment. These findings indicate a causal link between ceramide synthesis and ER stress in lipotoxicity, and imply that the consumption of diets enriched in MA and PA can cause NASH associated with lipodystrophy

Learning a Battery of COVID-19 Mortality Prediction Models by Multi-objective Optimization

The COVID-19 pandemic is continuously evolving with drastically changing epidemiological situations which are approached with different decisions: from the reduction of fatalities to even the selection of patients with the highest probability of survival in critical clinical situations. Motivated by this, a battery of mortality prediction models with different performances has been developed to assist physicians and hospital managers. Logistic regression, one of the most popular classifiers within the clinical field, has been chosen as the basis for the generation of our models. Whilst a standard logistic regression only learns a single model focusing on improving accuracy, we propose to extend the possibilities of logistic regression by focusing on sensitivity and specificity. Hence, the log-likelihood function, used to calculate the coefficients in the logistic model, is split into two objective functions: one representing the survivors and the other for the deceased class. A multi-objective optimization process is undertaken on both functions in order to find the Pareto set, composed of models not improved by another model in both objective functions simultaneously. The individual optimization of either sensitivity (deceased patients) or specificity (survivors) criteria may be conflicting objectives because the improvement of one can imply the worsening of the other. Nonetheless, this conflict guarantees the output of a battery of diverse prediction models. Furthermore, a specific methodology for the evaluation of the Pareto models is proposed. As a result, a battery of COVID-19 mortality prediction models is obtained to assist physicians in decision-making for specific epidemiological situations.This research is supported by the Basque Government (IT1504- 22, Elkartek) through the BERC 2022–2025 program and BMTF project, and by the Ministry of Science, Innovation and Universities: BCAM Severo Ochoa accreditation SEV-2017-0718 and PID2019-104966GB-I00. Furthermore, the work is also supported by the AXA Research Fund project “Early prognosis of COVID-19 infections via machine learning”

A spectroscopic atlas of post-AGB stars and planetary nebulae selected from the IRAS Point Source Catalogue

Aims: We study the optical spectral properties of a sample of stars showing far infrared colours similar to those of well-known planetary nebulae. The large majority of them were unidentified sources or poorly known in the literature at the time when this spectroscopic survey started, some 15 years ago. Methods: We present low-resolution optical spectroscopy, finding charts and improved astrometric coordinates of a sample of 253 IRAS sources. Results: We have identified 103 sources as post-AGB stars, 21 as ``transition sources'', and 36 as planetary nebulae, some of them strongly reddened. Among the rest of sources in the sample, we were also able to identify 38 young stellar objects, 5 peculiar stars, and 2 Seyfert galaxies. Up to 49 sources in our spectroscopic sample do not show any optical counterpart, and most of them are suggested to be heavily obscured post-AGB stars, rapidly evolving on their way to becoming planetary nebulae. Conclusions: An analysis of the galactic distribution of the sources identified as evolved stars in the sample is presented together with a study of the distribution of these stars in the IRAS two-colour diagram. Finally, the spectral type distribution and other properties of the sources identified as post-AGB in this spectroscopic survey are discussed in the framework of stellar evolution.Comment: 69 pages, 413 figures. Accepted by Astronomy and Astrophysic

Evaluation of pressure and temperature effect on the structure and properties of Ca2.93Sr0.07Co4O9 ceramic materials

In this work, the effect of hot-pressing conditions on the performances of Sr-doped Ca3Co4O9 materials has been investigated. The samples were prepared from attrition milled precursors, which reduced the processing time. Samples were hot-pressed at temperatures (T) between 800 and 900 °C and pressures (P) from 51 to 71 MPa. The out-of-plane X-ray diffraction (XRD) showed that all samples are formed by the thermoelectric phase, with a good grain orientation which is improved with T, and P, as demonstrated by their Lotgering factor. The observations through Scanning Electron Microscopy (SEM) have revealed that grain sizes and orientation are enhanced with T, and P, as well as density through Archimedes''s method. All these trends are reflected in the flexural strength and microhardness. The electrical resistivity is lower when the T, or P, is increased, reaching 6.4 mO cm for samples processed at 900 °C and 71 MPa, which is about the best reported values in the literature. On the other hand, contrarily to the expected results, they also showed the highest S values, 182 µV/K, which are similar to the best reported values for highly dense textured materials. Thermal conductivity values do not follow a regular evolution with the hot-pressing conditions, probably due to internal stresses, reaching the lowest values at 800 °C in samples processed at 800 °C and 51 MPa (1.51 W/(K*m)) or 900 °C and 61 MPa (1.53 W/(K*m)). Consequently, the highest ZT values have been determined in samples processed at 900 °C and 61 MPa (0.35) which is higher than the best reported values in literature for bulk textured samples, to the best of our knowledge. © 2021 The Author

CARACTERIZACIÓN DE LAS PROPIEDADES NUTRICIONALES Y ANTIOXIDANTES DE SEMILLAS DE QUINUA (Chenopodium quinoa WILLD.)

[EN] Interest in the cultivation of quinoa pseudo-cereal (Chenopodium quinoa Willd.) has increased in recent years due to its nutritional value, as well as its antioxidant capacity and phytochemical content. The chemical composition of quinoa seeds and their bioactive compounds can differ between varieties. In this study, the nutritional composition, antioxidant properties and total phenolic content of Yellow quinoa seeds cultivated in Mexico were evaluated. The results were compared with four commercial quinoa varieties from Peru: Yellow, Black, Red and Peruvian Yellow. The chemical composition of seeds in this study varied as a function of germplasm and growing conditions. In general, samples were characterized by their high carbohydrate content, followed by protein, lipids and fiber. The Yellow quinoa grown in Mexico stood out for its high phenolic content, as well as for its antioxidant activity, probably influenced by the presence of saponins.Carranza-Concha, J.; Chairez-Huerta, SG.; Contreras-Martinez, CS.; García Martínez, EM. (2021). Characterization of nutritional and antioxidant properties of Quinoa seeds (Chenopodium quinoa WILLD.). Revista Fitotecnia Mexicana. 44(3):357-366. http://hdl.handle.net/10251/18680435736644

Multiscale thermo-mechanical analysis of multi-layered coatings in solar thermal applications

Solar selective coatings can be multi-layered materials that optimize the solar absorption while reducing thermal radiation losses, granting the material long-term stability. These layers are deposited on structural materials (e.g., stainless steel, Inconel) in order to enhance the optical and thermal properties of the heat transfer system. However, interesting questions regarding their mechanical stability arise when operating at high temperatures. In this work, a full thermo-mechanical multiscale methodology is presented, covering the nano-, micro-, and macroscopic scales. In such methodology, fundamental material properties are determined by means of molecular dynamics simulations that are consequently implemented at the microstructural level by means of finite element analyses. On the other hand, the macroscale problem is solved while taking into account the effect of the microstructure via thermo-mechanical homogenization on a representative volume element (RVE). The methodology presented herein has been successfully implemented in a reference problem in concentrating solar power plants, namely the characterization of a carbon-based nanocomposite and the obtained results are in agreement with the expected theoretical values, demonstrating that it is now possible to apply successfully the concepts behind Integrated Computational Materials Engineering to design new coatings for complex realistic thermo-mechanical applications

Evaluation of the Impact of the COVID-19 Lockdown in the Clinical Course of Migraine

Objective: Previous studies have demonstrated that emotional stress, changes in lifestyle habits and infections can worsen the clinical course of migraine. We hypothesize that changes in habits and medical care during coronavirus disease 2019 (COVID-19) lockdown might have worsened the clinical course of migraine. Design: Retrospective survey study collecting online responses from migraine patients followed-up by neurologists at three tertiary hospitals between June and July 2020. Methods: We used a web-based survey that included demographic data, clinical variables related with any headache (frequency) and migraine (subjective worsening, frequency, and intensity), lockdown, and symptoms of post-traumatic stress. Results: The response rate of the survey was 239/324 (73.8%). The final analysis included 222 subjects. Among them, 201/222 (90.5%) were women, aged 42.5 ± 12.0 (mean±SD). Subjective improvement of migraine during lockdown was reported in 31/222 participants (14.0%), while worsening in 105/222 (47.3%) and was associated with changes in migraine triggers such as stress related to going outdoors and intake of specific foods or drinks. Intensity of attacks increased in 67/222 patients (30.2%), and it was associated with the subjective worsening, female sex, recent insomnia, and use of acute medication during a headache. An increase in monthly days with any headache was observed in 105/222 patients (47.3%) and was related to symptoms of post-traumatic stress, older age and living with five or more people. Conclusions: Approximately half the migraine patients reported worsening of their usual pain during the lockdown. Worse clinical course in migraine patients was related to changes in triggers and the emotional impact of the lockdown. © 2021 The Author(s) 2021. Published by Oxford University Press on behalf of the American Academy of Pain Medicine

Suppression of ferromagnetic ordering in doped manganites: Effects of the superexchange interaction

From a Monte Carlo study of the ferromagnetic Kondo lattice model for doped manganites, including the antiferromagnetic superexchange interaction ($J_{AF}$), we found that the ferromagnetic ordering was suppressed as $J_{AF}$ increased. The ferromagnetic transition temperature $T_c$, as obtained from a mean field fit to the calculated susceptibilities, was found to decrease monotonically with increasing $J_{AF}$. Further, the suppression in $T_c$ scales with the bandwidth narrowing induced by the antiferromagnetic frustration originating from $J_{AF}$. From these results, we propose that the change in the superexchange interaction strength between the $t_{2g}$ electrons of the Mn ions is one of the mechanisms responsible for the suppression in $T_c$ observed in manganites of the type (La$_{0.7-y}$Pr$_{y}$)Ca$_{0.3}$MnO$_3$.Comment: 5 pages, 6 figures. To appear in PR

Entornos virtuales de vídeo interactivo para neurorrehabilitación cognitiva

En pocos años, la discapacidad de origen cognitivo será uno de los principales problemas de salud. El déficit cognitivo influye en la ejecución de todas las actividades de la vida diaria. Pacientes con una afección de este tipo ven alterados su entorno social y familiar. Por todo ello, se hace imprescindible el desarrollo de programas de rehabilitación que permitan minimizar las consecuencias de las lesiones adquiridas y restituir o compensar las funciones afectadas. En la actualidad nos encontramos en un momento de cambio en las metodologías de la neurorrehabilitación, donde los entornos virtuales digitales interactivos son una fuente de innovación y una ventana terapéutica para la generación de nuevas estrategias basadas en una rehabilitación personalizada, monitorizada y ubicua, con la que lograr el máximo nivel de realización en las actividades de vida diaria. En este trabajo de investigación se plantea el uso del vídeo interactivo como medio tecnológico para realizar las terapias de rehabilitación cognitiva. Se presenta una prueba de concepto de una actividad de vida diaria y su posterior análisis por el equipo clínico del Instituí Guttmann. Los resultados preliminares apoyan su uso para alcanzar una rehabilitación basada en el nuevo paradigma

Validation of large-volume batch solar reactors for the treatment of rainwater in field trials in sub-Saharan Africa

The efficiency of two large-volume batch solar reactors [Prototype I (140 L) and II (88 L)] in treating rainwater on-site in a local informal settlement and farming community was assessed. Untreated [Tank 1 and Tank 2-(First-flush)] and treated (Prototype I and II) tank water samples were routinely collected from each site and all the measured physico-chemical parameters (e.g. pH and turbidity, amongst others), anions (e.g. sulphate and chloride, amongst others) and cations (e.g. iron and lead, amongst others) were within national and international drinking water guidelines limits. Culture-based analysis indicated that Escherichia coli, total and faecal coliforms, enterococci and heterotrophic bacteria counts exceeded drinking water guideline limits in 61%, 100%, 45%, 24% and 100% of the untreated tank water samples collected from both sites. However, an 8 hour solar exposure treatment for both solar reactors was sufficient to reduce these indicator organisms to within national and international drinking water standards, with the exception of the heterotrophic bacteria which exceeded the drinking water standard limit in 43% of the samples treated with the Prototype I reactor (1 log reduction). Molecular viability analysis subsequently indicated that mean overall reductions of 75% and 74% were obtained for the analysed indicator organisms (E. coli and enterococci spp.) and opportunistic pathogens (Klebsiella spp., Legionella spp., Pseudomonas spp., Salmonella spp. and Cryptosporidium spp. oocysts) in the Prototype I and II solar reactors, respectively. The large-volume batch solar reactor prototypes could thus effectively provide four (88 L Prototype II) to seven (144 L Prototype I) people on a daily basis with the basic water requirement for human activities (20 L). Additionally, a generic Water Safety Plan was developed to aid practitioners in identifying risks and implement remedial actions in this type of installation in order to ensure the safety of the treated water