Structural, electronic, and hyperfine properties of pure and Ta-doped m-ZrO₂

A combination of experiments and ab initio quantum-mechanical calculations has been applied to examine electronic, structural, and hyperfine interactions in pure and Ta-doped zirconium dioxide in its monoclinic phase (m-ZrO₂). From the theoretical point of view, the full-potential linear augmented plane wave plus local orbital (APW + lo) method was applied to treat the electronic structure of the doped system including the atomic relaxations introduced by the impurities in the host in a fully self-consistent way using a supercell approach. Different charge states of the Ta impurity were considered in the study and its effects on the electronic, structural, and hyperfine properties are discussed. Our results suggest that two different charge states coexist in Ta-doped m-ZrO₂. Further, ab initio calculations predict that depending on the impurity charge state, a sizeable magnetic moment can be induced at the Ta-probe site. This prediction is confirmed by a new analysis of experimental data

Advances in Alzheimer’s Disease Research: Human Cerebral Organoids

Alzheimer’s disease (AD) is the main neurodegenerative disorder in old age, causing memory impairment and dependency. The histopathology of AD is characterized by the presence of amyloid plaques and neurofibrillary tangles formed by Aβ peptide and hyperphosphorylated Tau, respectively. There is still no cure or effective treatment for AD. This could be due, in part, to the lack of suitable research models since animal models do not recapitulate the full physiological complexity of the human brain. With the development of induced pluripotent stem cells (iPSCs), these limitations could be overcome. Even so, the bi-dimensional (2D) culture models still do not allow to recapitulate all types of brain cells and do not show a three-dimensional (3D) arrangement. Since obtaining 3D cultures called organoids, a new opportunity arises to overcome the limitations of previous models. Human Cerebral Organoids (hCOs) represent a pioneering model, in which part of the complexity of the human brain is present. For this reason, they are fast becoming a very remarkable model for the study of the evolution of the molecular and cellular pathology of AD. This review provides a brief overview of AD research, focusing on the most recent advances achieved through the development of stem cell and cerebral organoid technologyThe authors would like to thank to financing entities: i. State R+D+i Program Oriented to the Challenges of Society. Ministry of Science and Innovation (PID2021-126715OB-I00). ii. Strategic Action in Intramural Health (PI22/00055). iii. Ministry of Science and Innovation and Universities, within the program “R&D Projects «Retos Investigación» (RTI2018-101663-B-100).S

Prevalence and Population Diversity of Listeria monocytogenes Isolated from Dairy Cattle Farms in the Cantabria Region of Spain

Listeria monocytogenes is an opportunistic pathogen that is widely distributed in the environment. Here we show the prevalence and transmission of L. monocytogenes in dairy farms in the Cantabria region, on the northern coast of Spain. A total of 424 samples was collected from 14 dairy farms (5 organic and 9 conventional) and 211 L. monocytogenes isolates were recovered following conventional microbiological methods. There were no statistically significant differences in antimicrobial resistance ratios between organic and conventional farms. A clonal relationship among the isolates was assessed by pulsed field gel electrophoresis (PFGE) analysis and 64 different pulsotypes were obtained. Most isolates (89%, n = 187) were classified as PCR serogroup IVb by using a multiplex PCR assay. In this case, 45 isolates of PCR serogroup IVb were whole genome-sequenced to perform a further analysis at genomic level. In silico MLST analysis showed the presence of 12 sequence types (ST), of which ST1, ST54 and ST666 were the most common. Our data indicate that the environment of cattle farms retains a high incidence of L. monocytogenes, including subtypes involved in human listeriosis reports and outbreaks. This pathogen is shed in the feces and could easily colonize dairy products, as a result of fecal contamination. Effective herd and manure management are needed in order to prevent possible outbreaks.This work was supported by Research Project grants RTA08-099, RTA2008-00080-C02, RTA2014-00045-C03-01 (INIA and FEDER) from the Spanish Ministry of Economy and Competitiveness and RTI2018-098267-R-C31 (INIA and FEDER) from the Spanish Ministry of Science and Innovation.S

Energy Drink Administration in Combination with Alcohol Causes an Inflammatory Response and Oxidative Stress in the Hippocampus and Temporal Cortex of Rats

Energy drinks (EDs) are often consumed in combination with alcohol because they reduce the depressant effects of alcohol. However, different researches suggest that chronic use of these psychoactive substances in combination with alcohol can trigger an oxidative and inflammatory response. These processes are regulated by both a reactive astrogliosis and an increase of proinflammatory cytokines such as IL-1β, TNF-α, and iNOS, causing cell death (apoptosis) at the central and peripheral nervous systems. Currently, mechanisms of toxicity caused by mixing alcohol and ED in the brain are not well known. In this study, we evaluated the effect of chronic alcohol consumption in combination with ED on inflammatory response and oxidative stress in the temporal cortex (TCx) and hippocampus (Hp) of adult rats (90 days old). Our results demonstrated that consuming a mixture of alcohol and ED for 60 days induced an increase in reactive gliosis, IL-1β, TNF-α, iNOS, reactive oxygen species, lipid peroxidation, and nitric oxide, in the TCx and Hp. We also found immunoreactivity to caspase-3 and a decrease of synaptophysin in the same brain regions. The results suggested that chronic consumption of alcohol in combination with ED causes an inflammatory response and oxidative stress, which induced cell death via apoptosis in the TCx and Hp of the adult rats

SINGLE-CELL sequencing workflow to study cellular composition and cell type specific expression profiles of human Cerebral Organoids

IBRO 11th World Congress of Neuroscience. Granada (Spain). 9-13 September 2023.Human cerebral organoid culture is a technology with immense potential in the areas of developmental neurobiology and neurodegeneration for example to study cell types, mechanisms involved, to discover of new biomarkers, to propose specific therapeutic strategies or to study the effects of compound-induced toxicity. Single-cell RNA sequencing (scRNA-seq) is a promising technology that will help to define the identity of the cerebral organoids and to understand cellular composition and cell type specific expression profiles. Standardization of workflows to do the scRNA-seq analysis is an important means to improve the use of this technology. We present the workflow and results of the scRNA-seq performed for cerebral organoids generated from the AND-2 cell line of human embryonic stem cells (hESCs). Dissociated cerebral organoid samples were loaded on the 10X Chromium and single cell libraries were prepared according to 10X Genomics standard procedures and sequenced on the Novaseq sequencer (Illumina).The data were checked and aligned to the GRCh38 human reference genome with CellRanger v6.0.2 and analyzed with Seurat v4.0. After quality filtering and data normalization with the SCTransform function, we performed Principal component analysis (PCA) using the highly variable genes, built a Shared Nearest Neighbor (SNN) graph using the Louvain method. To visualize data, Uniform Manifold Approximation and Projection (UMAP) dimensional reduction was performed. The identities of the cell clusters were assigned using the expression of genes specific of each cell type. We annotate in the AND2 cerebral organoids clusters for intermediate progenitor cells, astrocytes, oligodendrocyte precursor cells, excitatory neurons, inhibitory neurons, and mesodermal cells. We find also some cells in these organoids with expression of endothelial and microglial gene markers. Enrichment analysis of the highly variable differentially expressed genes (DEGs) was utilized to characterize the assigned cell types with Gene Ontology (GO), PanglaoDB and Cellmarker databases.S

VLTI status update: a decade of operations and beyond

We present the latest update of the European Southern Observatory's Very Large Telescope interferometer (VLTI). The operations of VLTI have greatly improved in the past years: reduction of the execution time; better offering of telescopes configurations; improvements on AMBER limiting magnitudes; study of polarization effects and control for single mode fibres; fringe tracking real time data, etc. We present some of these improvements and also quantify the operational improvements using a performance metric. We take the opportunity of the first decade of operations to reflect on the VLTI community which is analyzed quantitatively and qualitatively. Finally, we present briefly the preparatory work for the arrival of the second generation instruments GRAVITY and MATISSE.Comment: 10 pages, 7 figures, Proceedings of the SPIE, 9146-1

Enfrentando los riesgos socionaturales

El objetivo del libro es comprender la magnitud de los Riesgos Socionaturales en México y Latinoamérica, para comprender el peligro que existe por algún tipo de desastre, ya sea inundaciones, sismos, remoción en masa, entre otros, además conocer qué medidas preventivas, correctivas y de contingencias existen para estar atentos ante alguna señal que la naturaleza esté enviando y así evitar alguna catástrofe. El libro se enfoca en los aspectos básicos de análisis de los peligros, escenarios de riesgo, vulnerabilidad y resiliencia, importantes para la gestión prospectiva o preventiva

Changes in humoral immune response after SARS-CoV-2 infection in liver transplant recipients compared to immunocompetent patients

The protective capacity and duration of humoral immunity after SARS-CoV-2 infection are not yet understood in solid organ transplant recipients. A prospective multicenter study was performed to evaluate the persistence of anti-nucleocapsid IgG antibodies in liver transplant recipients 6 months after coronavirus disease 2019 (COVID-19) resolution. A total of 71 liver transplant recipients were matched with 71 immunocompetent controls by a propensity score including variables with a well-known prognostic impact in COVID-19. Paired case-control serological data were also available in 62 liver transplant patients and 62 controls at month 3 after COVID-19. Liver transplant recipients showed a lower incidence of anti-nucleocapsid IgG antibodies at 3 months (77.4% vs. 100%, p <.001) and at 6 months (63.4% vs. 90.1%, p <.001). Lower levels of antibodies were also observed in liver transplant patients at 3 (p =.001) and 6 months (p <.001) after COVID-19. In transplant patients, female gender (OR = 13.49, 95% CI: 2.17-83.8), a longer interval since transplantation (OR = 1.19, 95% CI: 1.03-1.36), and therapy with renin-angiotensin-aldosterone system inhibitors (OR = 7.11, 95% CI: 1.47-34.50) were independently associated with persistence of antibodies beyond 6 months after COVID-19. Therefore, as compared with immunocompetent patients, liver transplant recipients show a lower prevalence of anti-SARS-CoV-2 antibodies and more pronounced antibody levels decline

Diets based on virgin olive oil or fish oil but not on sunflower oil prevent age-related alvolar bone resorption by mitochondrial-related mechanisms

Background/Objectives: Aging enhances frequency of chronic diseases like cardiovascular diseases or periodontitis. Here we reproduced an age-dependent model of the periodontium, a fully physiological approach to periodontal conditions, to evaluate the impact of dietary fat type on gingival tissue of young (6 months old) and old (24 months old) rats.Methods/Findings: Animals were fed life-long on diets based on monounsaturated fatty acids (MUFA) as virgin olive oil, n-6 polyunsaturated fatty acids (n-6PUFA), as sunflower oil, or n-3PUFA, as fish oil. Age-related alveolar bone loss was higher in n-6PUFA fed rats, probably as a consequence of the ablation of the cell capacity to adapt to aging. Gene expression analysis suggests that MUFA or n-3PUFA allowed mitochondria to maintain an adequate turnover through induction of biogenesis, autophagy and the antioxidant systems, and avoiding mitochondrial electron transport system alterations.Conclusions: The main finding is that the enhanced alveolar bone loss associated to age may be targeted by an appropriate dietary treatment. The mechanisms involved in this phenomenon are related with an ablation of the cell capacity to adapt to aging. Thus, MUFA or n-3PUFA might allow mitochondrial maintaining turnover through biogenesis or autophagy. They might also be able to induce the corresponding antioxidant systems to counteract age-related oxidative stress, and do not inhibit mitochondrial electron transport chain. From the nutritional and clinical point of view, it is noteworthy that the potential treatments to attenuate alveolar bone loss (a feature of periodontal disease) associated to age could be similar to some of the proposed for the prevention and treatment of cardiovascular diseases, a group of pathologies recently associated with age-related periodontitis.This study was supported by I+D grants from the Spanish Ministry of Education and Science (AGL2008-01057) and the Autonomous Government of Andalusia (AGR832)