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CASPT2 Study of the Unimolecular Reactions of Nitromethane—A Look at the Roaming Reactions in the Decomposition of Nitromethane: An Exergonic Route at High Temperatures.
Get PDFIn this work, we studied the main decomposition reactions on the ground state of nitromethane (CH3NO2) with the CASPT2 approach. The energetics of the main elementary reactions of the title molecule have been analyzed on the basis of Gibbs free energies obtained from standard expressions of statistical thermodynamics. In addition, we describe a mapping method (orthogonalized 3D representation) for the potential energy surfaces (PESs) by de ning an orthonormal basis consisting of two Rn orthonormal vectors (n, internal degrees of freedom) that allows us to obtain a set of ordered points in the plane (vector subspace) spanned by such a basis. Geometries and harmonic frequencies of all species and orthogonalized 3D representations of the PESs have been computed with the CASPT2 approach. It is found that all of the analyzed kinetically controlled reactions of nitromethane are endergonic. For such a class of reactions, the dissociation of nitromethane into CH3 and NO2 is the process with the lower activation energy barrier (∆G); that is, the C-N bond cleavage is the most favorable process. In contrast, there exists a dynamically controlled process that evolves through a roaming reaction mechanism and is an exergonic reaction at high temperatures: CH3NO2 → [CH3. . .NO2]* → [CH3ONO]* → CH3O + NO. The above assertions are supported by CASPT2 mappings of the potential energy surfaces (PESs) and classical trajectories obtained by “on-the y” CASSCF molecular dynamics calculations.Spanish Ministry of Science and Innovation (MCIN/AEI/10.13039/ 501100011033) through project PID2021-122613OB-I0
How much energy can a chemical bond withstand?
Get PDFSe trata de una conferencia científica del Prof. Valentín García Baonza de la UCM a impartir en la Fac. de Ciencias el 18 del junio de 2025Título de la conferencia: ¿Cuánta energía admite un enlace químico?
Resumen: Se discutirá un modelo general que relaciona la energía de
un enlace químico con las distancias máxima y mínima en las que
dicho enlace se puede considerar estable mecánicamente. A partir deresultados de espectroscopía de vibración y simulacionescomputacionales se demostrará la validez e implicaciones del modelo en ejemplos que involucran enlaces C-C y enlaces de hidrógeno
Patients' Experiences Following Osteoarticular Foot Surgery for Rheumatoid Arthritis-Related Deformities: A Qualitative Study.
Get PDFRheumatoid arthritis (RA) is a chronic autoimmune
disease that frequently causes foot deformities, decreasing mobility and quality of life.
Although surgical interventions seek to alleviate these alterations, the long-term experiences of patients have not been deeply explored. The aim of this study was to describe the
experiences of patients with RA undergoing osteoarticular surgery to correct acquired foot
deformities. Materials and Method: A qualitative study design was used with structured
interviews including 19 patients with RA treated in a specialised rheumatology service. The
thematic analysis was carried out using the Braun and Clarke thematic analysis, ensuring
compliance with ethical standards and the anonymity of the participants. Results: Five
main themes were identified: experience with pain before and after surgery; impact on
functional capacity; complications and need for additional surgeries; emotional impact
and quality of life; overall satisfaction with the surgery. While many patients reported
significant pain reduction and functional improvements, others faced recurrences of the
deformities, persistent pain, and post-surgical complications. Emotional responses ranged
from well-being to frustration, depending on surgical outcomes. The five-year follow-up
period allowed for a comprehensive assessment of the long-term impact of surgery. The
recurrence rate of deformities was notable, and the emotional impact of these recurrences
was significant, with patients expressing frustration and distress in some cases. Conclusions:
The patients’ experiences were heterogeneous, with both positive and negative outcomes.
These findings underscore the importance of individualized management and comprehensive follow-up that consider the clinical outcomes, expectations, and emotional well-being
of RA patients undergoing foot surger
Clampaje temporal de las arterias uterinas para la prevención de la hemorragia durante la cesárea. Resultados de implantación en la morbilidad materna.
No full textObjetivo del Estudio
Evaluar la eficacia del clampage temporal de las arterias uterinas (CTAU) Como método para reducir la pérdida de sangre durante la cesárea y su impacto en la morbilidad materna.
Introducción
• La cesárea es una de las intervenciones quirúrgicas más comunes en obstetricia, pero también conlleva riesgos, en la hemorragia posparto (HPP) una de las principales causas de morbilidad y mortalidad materna.
• Se plantea el CTAU como técnica una innovadora para controlar la credibilidad de la credibilidad de la credibilidad de la credibilidad.
Metodología
• Diseño del estudioLongitudinal, prospectivo y cuasiexperimental.
• Muestra180 pacientes sometidos a cesárea en el Hospital Universitario Regional de Málaga (Otubre 2023 - enero 2024).
• Grupos :
• Grupo experimentalSe aplica CTAU.
• Control de GrupoCesáreas sin CTAU.
• Variables analizadas:
• Niveles de hemoglobina antes y después de la cirugía.
• Días de hospitalización.
• Necesidad de transfusión.
• Complicaciones postoperatorias.
Resultados
• Reducción significativa de la pérdida de sangre intraoperatoria en el grupo con CTAU.
• Menor secunda en los niveles de hemoglobina postquirúrgica, lo que redujo la necesidad de transfusiones.
• Disminución en los tiempos de hospitalización y recuperación.
• Ausencia de efectos se frustró a la técnica.
Conclusiones
• El CTAU es una técnica efectiva y segura para reducir el HPP en cesáreas.
• Minimiza la necesidad de transfusiones y procedimientos evitan más invasivos como la histeclectomía.
• Puede mejorar los resultados maternos y optimizar los recursos hospitalarios en diversos entornos clínicos
Chemistry inquiry conducted by secondary school students into material degradation in the context of sustainability
No full textUnderstanding the relationship between chemistry and society is crucial for addressing material degradation and its environmental impact. This study highlights the importance of chemistry education in fostering sustainability awareness through inquiry-based learning. Ninth-grade students conducted an inquiry into material degradation, analyzing environmental factors such as photodegradation, biodegradation, and corrosion. Their findings show that materials such as plastic and metal degrade minimally over 100 days, reinforcing the need for sustainable solutions. This approach advances sustainability by integrating scientific inquiry into education, promoting responsible consumption and green chemistry. This study aligns with UN SDGs, particularly Goal 4 (Quality Education), Goal 12 (Responsible Consumption and Production), and Goal 13 (Climate Action), by fostering scientific literacy and ecological responsibility in future generations.Gobierno de España, Ministerio de Ciencia, Innovación y Universidades; Agencia Estatal de Investigación; Next Generation E
Essays on financial literacy in the business and management fields
Get PDFEsta tesis doctoral tiene como objetivo extender el limitado conocimiento existente acerca de las implicaciones de la cultura financiera en las áreas de negocio y gestión empresarial, a través del desarrollo de tres proyectos de investigación que estudian la cultura financiera tanto desde la perspectiva del individuo como de la empresa. A nivel individual, busca profundizar en el papel multidimensional de la cultura financiera -entendida como conocimiento, actitud y comportamiento financieros- en la propensión a tomar riesgos de un relevante segmento de la población, los estudiantes universitarios. En el ámbito empresarial, por su parte, acomete dos objetivos. Por un lado, desarrollar un marco integrador que recoja de manera rigurosa, homogénea y consistente la evidencia empírica existente en la literatura sobre la cultura financiera en pequeñas y medianas empresas (PYMEs). Por otro, analizar el papel de la cultura financiera de los directores generales en el compromiso medioambiental de este extendido segmento de empresas. Para dar respuesta a estas problemáticas, recopila datos de fuentes primarias y secundarias, y emplea diversas técnicas econométricas y de revisión de la literatura. Respecto a la estructura, esta tesis doctoral responde a la modalidad por compendio de publicaciones. Se comienza con una breve introducción, en la que pone de manifiesto la relevancia e interés que hoy día tiene la cultura financiera desde un punto de vista institucional, tanto a nivel nacional como internacional. Asimismo, se argumenta la destacada posición que ocupa la academia como principal propulsor de una mayor concienciación general sobre su relevancia, siendo la responsable de que la investigación sobre cultura financiera sea hoy día un campo de estudio oficial de la profesión económica.Tras identificar la motivación de cada uno de los proyectos investigados, así como sus principales novedades con respecto a trabajos previos, se procede con los tres capítulos que dan forma a la presente tesis doctoral. Cada capítulo aborda un proyecto de investigación concreto y publicado en una revista científica especializada en la temática. El primer capítulo profundiza en el mecanismo de asociación a través del cual la cultura financiera estimula de forma positiva la propensión a tomar riesgos de los estudiantes universitarios, identificando el papel concreto del conocimiento, la actitud y el comportamiento financiero. El segundo capítulo construye un marco integrador que recoge la estructura intelectual de la investigación empírica sobre la cultura financiera en PYMEs junto a las raíces teóricas que la sustentan, sentando las bases de este emergente campo de investigación. El tercer capítulo analiza el papel de la cultura financiera de los directores generales de PYMEs en la adopción de prácticas medioambientalmente sostenibles, explorando la innovación de procesos como el mecanismo de asociación requerido para que se produzca dicha relación. Concluidos los tres capítulos, se presentan los principales resultados y conclusiones de la tesis, así como un resumen que integra toda la investigación abordada. Por tanto, esta tesis doctoral no solo solo contribuye de forma teórica a la literatura previa sobre cultura financiera a nivel individual y empresarial, sino que aporta una serie de implicaciones prácticas y líneas de actuación destacadas que pueden resultar de utilidad para profesionales y legisladores
Hyperparameter optimization of YOLO models for invasive coronary angiography lesion detection and assessment
Get PDFCoronary artery disease (CAD) remains the leading cause of mortality, creating an urgent need for reproducible, image-based decision support. Although YOLOv8-based detectors underpin much of today’s state-of-the-art stenosis detection, their accuracy is sensitive to dozens of interacting hyperparameters. We therefore perform a systematic study of hyperparameter optimizers for YOLO-style models, pairing YOLOv8 and its Double Coordinate Attention (DCA) variant with three model-based engines: Covariance-Matrix-Adaptation Evolution Strategy (CMA-ES), Tree-structured Parzen Estimator (TPE), and a Gaussian-process sampler; and contrasting them with Random Search and the mutation-only routine that serves as the default optimizer in the ultralytics package.
Optimization targets binary detection and was benchmarked using the CADICA (full sequences) and ARCADE (single key-frames) datasets, maximizing the F1-Score under stratified three-fold cross-validation within a fixed compute budget. Model-based methods consistently lift the F1-speed Pareto frontier: CMA-ES attains
on v8l, while Bayesian strategies top the medium and small backbones with
(v8m) and
(v8s). All surpass the default optimizer and yield more lesion-centric EigenCAM saliency, confirming the value of adaptive probabilistic search for tuning high-dimensional YOLO-based CAD pipelines. The complete code-base is open-source and released at https://github.com/MarioPasc/Coronary_Angiography_Detection.Funding for open access charge: Universidad de Málaga / CBU
Adaptation and validation of the Persian version of the foot Health Status Questionnaire in patients with plantar pain: evaluation of test-retest
Get PDFBackground: The Foot Health Status Questionnaire (FHSQ) is a foot health psychometric tool
for measuring foot health status that consists of eight dimensions. Currently, the FHSQ has been
adapted to several languages. It was considered necessary to translate and adapt the FHSQ to
the Persian language. Thus, the aim of this study was to assess the repeatability and reliability of
the Foot Health Status Questionnaire (FHSQ) translated into Persian.
Method: The translation into Persian and test-retest reliability methods came from the English
version of the questionnaire. The questionnaire was distributed to 88 individuals diagnosed with
plantar heel pain, who were recruited from a podiatry clinic in Iran. To assess test-retest reliability,
the instrument was administered on two separate occasions, with a five-day interval between the
initial and follow-up assessments.
Results: As regards the total mark for each dimension, internal consistency and reliability were
determined with the Cronbach α and intraclass correlation coefficient (ICC) with a confidence
interval (CI) of 95%. High internal consistency was shown for the eight dimensions: (a) foot pain,
with a Cronbach α of 0.773; (b) foot function and (c) general foot health with 0.788 and 0.776
respectively; (d) shoe with 0.793; (e) general health with 0.784; (f) physical function with 0.795;
(g) social function with 0.801 and (h) vigour with 0.748. Excellent test-retest reliability (ICC = 0.911
[95% CI =0.844–0.949]) was shown for the total score.
Conclusions: The Persian version of the FHSQ was shown to be a valid and reliable tool for
acceptable use in the Iran population
Fluctuations of CO₂ and 222Rn concentration in the karst vadose zone: Comparing exhalation, indoor concentrations, and cave air dynamics (Nerja Cave, Southern Spain)
Get PDFTo investigate the influence of atmospheric and subsurface karst conditions on gas transport in the vadose zone and across the epikarst-atmosphere interface, we measured: a) radon (222Rn) and carbon dioxide (CO2) concentrations in the air of two boreholes drilled in the vadose zone, where high levels of these gases had been previously reported, and b) indoor radon concentrations in two dwellings built on potentially karstifiable lithologies. One dwelling (D1) is located near the boreholes and a major tourist cave (Nerja Cave), while the other (D2) is in the town of Nerja.
Periodic fluctuations in gas concentrations were observed in the boreholes, reflecting advective transport of atmospheric air into the subsurface (inflow) and from the vadose zone into the atmosphere (outflow). Gas transport was mainly driven by barometric pumping, whose efficiency depends on vadose zone permeability, although thermal-induced convection was also detected. Advective transport was more effective in winter than in summer. In the dwellings, high 222Rn concentrations resulted from subsurface radon infiltration into the buildings. Radon transport indoors was mainly driven by depressurization of the dwellings due to temperature gradients and barometric pumping (D1), as well as wind effects and ventilation habits (D2).
The presence of large karstic cavities may play a supplemental role in the indoor radon concentrations in nearby buildings. Finally, some anomalies in vadose air radon concentrations appear to be linked to seismic activity, though further research is needed to confirm this relationship.Funding for open access charge: Universidad de Málaga / CBU
Physical and mental health issues during the COVID-19 lockdown by gender: a survey of the Andalusian population in Spain
Get PDFThe COVID-19 outbreak brought a period of health and economic crisis worldwide, with experts disagreeing on how long it will last. In this context, we have analysed the influence that the lockdown in Spain, one of the most restrictive in the world, had on individuals in terms of their physical and mental health conditions. In order to study this issue, a sample of 2,950 secondary data from Andalusia, the most populated Spanish region (with 8.5 million inhabitants in 2020), was collected during the lockdown period using stratified random sampling (with the province and the degree of urbanisation as stratum, and individuals as units of analysis). The methodology employed for this purpose was time fixed-effects estimates, enabling us to control by many unobservables which are the same within-individuals between-years, although still obtaining conditional associations. Specifically, this study is novel to the extent that it employs recent data to analyse the consequences of the lockdown on the physical and mental health of the Andalusian population using time fixed-effects, which fulfils the gap in the literature for this issue and region. We found that the state of physical health of the Andalusian population does not seem to have deteriorated due to the lockdown. However, mental health may have declined by 0.38 points due to the lockdown, especially in the case of women, whose mental health seems to have been harmed additionally by 0.10 points. These results may indicate that policy measures should be aimed at a better management of a pandemic situation and at providing psychological help for persons whose mental health was negatively affected during the lockdown and find it difficult to recover.Funding for open access charge: Universidad de Málaga / CBU