A DFT study on natural sensitizers with donor-p-acceptor architecture based on 1,7-diazaheptametine for applications in Dye-Sensitized Solar Cells (DSSC)

Nature offers a wide range of organic dyes with potential as sensitizers in DSSC technology. Among them, some natural dyes contain a 1,7-diazaheptamethine system, influencing their chromatic properties. In this investigation, we computationally analyzed 21 natural betalain dyes featuring a common structural moiety through Density Functional Theory calculations. Among them, eight dyes were classified under the betacyanin subfamily, while the remaining thirteen were attributed to the betaxanthin subfamily. These dyes were examined both in isolation and when bound to titanium dioxide (dye@TiO2). The betaxanthin subfamily showed more twisted geometries, while the betacyanin subfamily exhibited a smaller energy gap. All isolated dyes or dyes@TiO2 exhibit maximum absorption peaks within the visible region (350–700 nm), showcasing their light-capturing capacity. Stability, evidenced by negative adsorption energies, suggests the spontaneity of the adsorption process. Furthermore, our results indicate that the nature of bonding significantly influences the electronic properties of dye@TiO2 complexes. Collectively, these results underscore the importance of the 1,7-diazaheptamethine system in imparting color and structure to these dyes. Our thorough analysis, encompassing molecular interactions, geometric attributes—especially the configuration of donor groups—electronic properties, and absorption spectra, provides valuable insights into the potential applications and effectiveness of these dyes for incorporation in dye-sensitized solar cells (DSSC)

Differences in commuting between employee and self-employed workers: The case of Latin America

Commuting time represents a shock to worker time allocations that ultimately affects wellbeing. This paper analyzes the commuting behavior of employee and self-employed workers in urban areas of eleven Latin American countries. Using data from the ECAF data, results show that employees spend about 8.2 more minutes commuting to work than their self-employed counterparts, net of observable characteristics, a difference of around 18.5% of the employees' commuting time. This difference is qualitatively robust across the eleven countries and is concentrated in commutes by public transit, but is not explained by differences in access to public transit services. This analysis is a first cross-country exploration of self-employed and employee workers' commuting time in Latin America. By analyzing differences in commuting time between these two groups of workers, our analysis may serve to guide future planning programs

Baseline clinical characteristics and phenoendotypes of patients with severe asthma in Alergodata: the Spanish Allergy Society Registry

Asthma is a heterogeneous chronic condition comprising several phenotypes with similar clinical manifestations [1]. Between 5% and 10% of asthma patients have severe asthma (SA) [2], and despite appropriate therapy, symptoms remain uncontrolled in approximately 50% [3]. Chronic rhinosinusitis is a group of disorders that also comprises several phenotypes, the most debilitating of which is CRS with nasal polyps (CRSwNP), which affects 2.1% to 4.4% of people in Europe [4]. The lack of highly effective therapy for CRSwNP means that adults experience severe lower airway disease [4]. SA and CRSwNP often co-occur [4]. Asthma is estimated to affect 40% to 70% of patients with CRSwNP, and the frequency of CRSwNP ranges from 57% to 62% in SA; both situations are associated with worse outcomes [4]..

ChatGPT es un estudiante por encima de la media en la Facultad de Medicina de la Universidad de Zaragoza y un colaborador excelente en la elaboración de material docente

Introducción y objetivo: La inteligencia artificial se halla plenamente presente en nuestras vidas. En educación las posibilidades de su uso son infinitas, tanto para alumnos como para docentes. Material y métodos: Se ha explorado la capacidad de ChatGPT a la hora de resolver preguntas tipo test a partir del examen de la asignatura Procedimientos Diagnósticos y Terapéuticos Anatomopatológicos de la primera convocatoria del curso 2022-2023. Además de comparar su resultado con el del resto de alumnos presentados, se han evaluado las posibles causas de las respuestas incorrectas. Finalmente, se ha evaluado su capacidad para realizar preguntas de test nuevas a partir de instrucciones específicas. Resultados: ChatGPT ha acertado 47 de las 68 preguntas planteadas, obteniendo una nota superior a la de la media y mediana del curso. La mayor parte de preguntas falladas presentan enunciados negativos, utilizando las palabras «no», «falsa» o «incorrecta» en su enunciado. Tras interactuar con él, el programa es capaz de darse cuenta de su error y cambiar su respuesta inicial por la correcta. Finalmente, ChatGPT sabe elaborar nuevas preguntas a partir de un supuesto teórico o bien de una simulación clínica determinada. Conclusiones: Como docentes estamos obligados a explorar las utilidades de la inteligencia artificial, e intentar usarla en nuestro beneficio. La realización de tareas que suponen un consumo de tipo importante, como puede ser la elaboración de preguntas tipo test para evaluación de contenidos, es un buen ejemplo

Subolesin knockdown in tick cells provides insights into vaccine protective mechanisms

Ticks as obligate blood-feeding arthropod vectors of pathogenic viruses, bacteria, protozoa and helminths associated with prevalent tick-borne diseases (TBDs) worldwide. These arthropods constitute the second vector after mosquitoes that transmit pathogens to humans and the first vector in domestic animals. Vaccines constitute the safest and more effective approach to control tick infestations and TBDs, but research is needed to identify new antigens and improve vaccine formulations. The tick protein Subolesin (Sub) is a well-known vaccine protective antigen with a highly conserved sequence at both gene and protein levels in the Ixodidae and among arthropods and vertebrates. In this study, transcriptomics and proteomics analyses were conducted together with graph theory data analysis in wild type and Sub knockdown (KD) tick ISE6 cells in order to identify and characterize the functional implications of Sub in tick cells. The results support a key role for Sub in the regulation of gene expression in ticks and the relevance of this antigen in vaccine development against ticks and TBDs. Proteins with differential representation in response to Sub KD provide insights into vaccine protective mechanisms and candidate tick protective antigens

Upper boundary on tree cover at global drylands

A comment on Holdo & Nippert (2023): ‘Linking resource- and disturbance-based models to explain tree–grass coexistence in savannas’ In their recent Tansley Review, Holdo & Nippert (2023) provide a comprehensive analysis of existing models that explain tree–grass coexistence along precipitation gradients in savannas. They highlight the diverse assumptions of the different models proposed in the literature and conclude that none can fully explain tree–grass coexistence along a rainfall gradient. Consequently, they propose essential elements that a synthetic model should incorporate to solve the ‘treeness conundrum’ (sensu House et al., 2003). Holdo & Nippert assert that tree dominance is mainly limited by ecohydrological mechanisms in dry savannas and by disturbances in wet savannas. These concepts and mechanisms are summarized in their fig. 1, where they modify the ‘Sankaran curve’ estimated for Africa (Sankaran et al., 2005) to account for the effect of soil texture along rainfall gradients (upper boundary on tree cover is achieved with lower precipitation in coarser than in fine soils)

Body image and dietary habits in adolescents: a systematic review

Context: Adolescence is a critical developmental stage in which increasing concerns about body image (BI) coincide with the consolidation of dietary habits (DHs). Multiple studies have sought robust associations between BI and DHs to prevent unhealthy behaviors. Objective: The aim of this systematic review was to examine the available literature on the association between BI perception (BIP) and/or satisfaction (BIS) and DHs in adolescents. Data Sources: A search was carried out of 5 electronic databases (PubMed, SciELO, Cochrane, Embase, and PsycInfo) using a combination of keywords (and synonyms) related to adolescence, BI, and diet. Data Extraction: Data screening, extraction, and quality assessment were performed independently by 2 investigators using the PRISMA and AXIS guidelines. Data Analysis: Of 2496 articles screened, 30 articles, published in English or Spanish, that evaluated the relationship between BI and DHs in adolescents aged between 10 years and 18 years, were included. A relationship between accurate BI perception in adolescents and healthy DHs was reported in 5 articles (16.2%). A relationship between overestimation of body weight in adolescents and healthy DHs was reported in 4 articles (13.3%). A relationship between underestimation of body weight and unhealthy DHs was reported in 8 articles (26.7%). In addition, 4 articles (13.3%) reported a relationship between BIS and healthy DHs. The desire to gain weight was associated with unhealthy DHs in 3 (10%) of the articles, while the desire to lose weight was related to healthy DHs in 3 (10%) of the articles and to unhealthy DHs in 3 (10%) other articles. There were also gender differences in the relationship between BIP or BIS and DHs. Conclusion: Adolescents who underestimate their body weight tend to report less healthy DHs than body weight overestimators. Adolescents unsatisfied with their BI and with a drive for thinness frequently engage in DHs linked to losing weight. Systematic Review Registration: PROSPERO registration no. CRD42020184625

Dynamics of excitable cells: spike-adding phenomena in action

We study the dynamics of action potentials of some electrically excitable cells: neurons and cardiac muscle cells. Bursting, following a fast–slow dynamics, is the most characteristic behavior of these dynamical systems, and the number of spikes may change due to spike-adding phenomenon. Using analytical and numerical methods we give, by focusing on the paradigmatic 3D Hindmarsh–Rose neuron model, a review of recent results on the global organization of the parameter space of neuron models with bursting regions occurring between saddle-node and homoclinic bifurcations (fold/hom bursting). We provide a generic overview of the different bursting regimes that appear in the parametric phase space of the model and the bifurcations among them. These techniques are applied in two realistic frameworks: insect movement gait changes and the appearance of Early Afterdepolarizations in cardiac dynamics

The Composite Improved Generalized Steinmetz Equation (ciGSE): an Accurate Model Combining the Composite Waveform Hypothesis with Classical Approaches

Predicting core losses is a difficult task for designing magnetic components. Under triangular current waveforms the classical approaches work with duty cycles close to 0.5 but are inaccurate for high and low duty cycles. In this work, the composite waveform hypothesis is tested, using data from the MagNet database for N87 material at 25 °C (3312 data points). Limitations of the composite waveform hypothesis are discussed and a technique to expand the loss space is presented. The new approach based in an extended loss space is validated against the classical improved Generalized Steinmetz Equation, reducing the root mean square and 95 percentile errors by 5.85 and 6.96 times, allowing to predict core losses accurately even at high and low duty cycles. A direct correlation between the expanded loss space and the Steinmetz parameters from the improved Generalized Steinmetz Equation is proven, allowing to represent the core losses as functions of these parameters and generating the composite improved Generalized Steinmetz Equation. The proposed methodology for core loss prediction is validated making use of all data available from the MagNet database (10 materials, 4 temperatures, 59 423 data points), achieving better results than the commonly used improved Generalized Steinmetz Equation