Universidad de Sevilla
Recent publications
In this paper, the b-coloring problem is solved for every subdivision-edge neighbourhood corona of paths, cycles, stars and complete graphs. In addition, some exact values and sharp bounds are established for the b-chromatic number of subdivision-edge neighbourhood coronas of these graphs with any other graph.
Modular multilevel converters (MMCs) have emerged as an attractive converter topology for renewable energy integration systems. A smooth operation of an MMC depends on proper regulation of multiple control variables, e.g., phase current, circulating current, capacitor voltage, etc. The model predictive control (MPC) is an excellent candidate for such a scenario since different control objectives can be simultaneously handled in a unified cost function. Though extensive research has been conducted in the literature, a computationally efficient MPC implementation capable of regulating the common-mode voltage (CMV) of the AC-side neutral point of an MMC as a control target has not been properly investigated. This article proposes such an MPC strategy that can flexibly regulate the CMV by incorporating the CMV tracking error into the cost function. The biggest challenge is the dramatically increased number of available control actions and the consequent computational burden as the three phases are controlled as a whole, which are addressed employing a quadratic programming technique, leading to only 64 cost-function evaluations per control period regardless of the number of submodules of the MMC. Several experiments and simulations are carried out considering the regulation of the CMV in different scenarios, and the results validate the effectiveness of the proposed method.
Recent systematic reviews suggest that pharmacists' interventions in asthma patients have a positive impact on health‐related outcomes. Nevertheless, the association is not well established, and the role of clinical pharmacists is poorly represented. The aim of this overview of systematic reviews is to identify published systematic reviews assessing the impact of pharmacists' interventions on health‐related outcomes measured in asthma patients. PubMed, Embase, Scopus, and Cochrane Library were searched from inception to December 2022. Systematic reviews of all study designs and settings were included. Methodological quality was assessed using AMSTAR 2. Two investigators performed study selection, quality assessment and data collection independently. Nine systematic reviews met the inclusion criteria. Methodological quality was rated as high in one, low in two, and critically low in six. Reviews included 51 primary studies reporting mainly quality of life, asthma control, lung capacity, and therapeutic adherence. Only four studies were carried out in a hospital setting and only two reviews stated the inclusion of severe asthma patients. The quality of the systematic reviews was generally low, and this was the major limitation of this overview of systematic reviews. However, solid evidence supports that pharmaceutical care improves health‐related outcomes in asthma patients.
Non-university teaching staff must use social media platforms (SMP) to update themselves on educational matters. This study aims to analyze how these teachers in Spanish non-university education, differentiating between men and women, value and use SMPs to update themselves in educational matters. A total of 463 Spanish teachers participated in this survey-type study. The results show that the perception of usefulness, responsible use, and the role of educational institutions and agents remains medium or low. At the descriptive level, differences between men and women are detected in the perceptions of the teachers surveyed, with female teachers having a more favourable perception of the usefulness, use, and role of social media assumed by the institutions in which they work professionally compared to male teachers. It is concluded that there are three profiles of non-university teachers according to the variables analyzed that do not show differences according to the sex of the teachers. The implications of this study help to propose actions that help improve the scenario by 1) increasing the training channels, 2) increasing the levels of educational innovation through SMP, 3) increasing the effectiveness of teaching–learning strategies, and 4) promoting of skills that contribute to greater use and perception of these scenarios for the training of teachers and students.
We study the thermal properties of a bulk $$\hbox {Ni}_{55}\hbox {Fe}_{19}\hbox {Ga}_{26}$$ Ni 55 Fe 19 Ga 26 Heusler alloy in a conduction calorimeter. At slow heating and cooling rates ( $$\sim {1}\,\hbox {K h}^{-1}$$ ∼ 1 K h - 1 ), we compare as-cast and annealed samples. We report a smaller thermal hysteresis after the thermal treatment due to the stabilization of the 14 M modulated structure in the martensite phase. In ultraslow experiments ( $${40}\,\hbox {mK h}^{-1}$$ 40 mK h - 1 ), we detect and analyze the calorimetric avalanches associated with the direct and reverse martensitic transformation from cubic to 14 M phase. This reveals a distribution of events characterized by a power law with exponential cutoff $$p(u)\propto u^{-\varepsilon }\exp (-u/\xi )$$ p ( u ) ∝ u - ε exp ( - u / ξ ) where $$\varepsilon \sim 2$$ ε ∼ 2 and damping energies $$\xi ={370}{\upmu {\rm J}}$$ ξ = 370 μ J (direct) and $$\xi ={27}{\upmu {\rm J}}$$ ξ = 27 μ J (reverse) that characterize the asymmetry of the transformation.
This study presents the synthesis of agro-waste banana peel extract-based magnetic iron oxide nanoparticles (BPEx-MIONPs), emphasizing antioxidant capacity and food preservation. Using iron (III) chloride hexahydrate (FeCl3 · 6 H2O) as a precursor and a reducing agent from agro-waste peel extract, a precisely controlled process yielded BPEx-MIONPs. Characterization involved X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and Fourier-transform infrared spectroscopy (FTIR). XRD revealed tetragonal Fe2O3, cubic magnetite structure, and monoclinic FexOy-NPs with an average size of 14.8 nm. TEM and SEM revealed diverse morphologies. TEM displayed both spherical and elongated nanoparticles, with some appearing as thin fibrils. In contrast, SEM images depicted an array primarily consisting of spherical nanoparticles, resembling coral reef formations. FTIR confirmed Fe–O bonds (1000 –400 cm⁻¹). The antioxidant assessment showed robust DPPH free radical scavenging; BPEx achieved 100% inhibition at 18 min, and BPEx-MIONPs had an IC50 of ~ 136 µg/mL. BPEx-MIONPs, stabilized with banana-based bioplastic, effectively preserved grapes, reducing weight loss to 6.2% on day 3, compared to the control (19.0%). This pioneering study combines banana peel antioxidants with magnetic iron oxide nanoparticles, providing sustainable solutions for food preservation and nano-packaging. Ongoing research aims to refine conditions and explore broader applications of BPEx-MIONPs. Graphical Abstract
HMGA1 is a structural epigenetic chromatin factor that has been associated with tumor progression and drug resistance. Here, we reported the prognostic/predictive value of HMGA1 for trabectedin in advanced soft-tissue sarcoma (STS) and the effect of inhibiting HMGA1 or the mTOR downstream pathway in trabectedin activity. The prognostic/predictive value of HMGA1 expression was assessed in a cohort of 301 STS patients at mRNA (n = 133) and protein level (n = 272), by HTG EdgeSeq transcriptomics and immunohistochemistry, respectively. The effect of HMGA1 silencing on trabectedin activity and gene expression profiling was measured in leiomyosarcoma cells. The effect of combining mTOR inhibitors with trabectedin was assessed on cell viability in vitro studies, whereas in vivo studies tested the activity of this combination. HMGA1 mRNA and protein expression were significantly associated with worse progression-free survival of trabectedin and worse overall survival in STS. HMGA1 silencing sensitized leiomyosarcoma cells for trabectedin treatment, reducing the spheroid area and increasing cell death. The downregulation of HGMA1 significantly decreased the enrichment of some specific gene sets, including the PI3K/AKT/mTOR pathway. The inhibition of mTOR, sensitized leiomyosarcoma cultures for trabectedin treatment, increasing cell death. In in vivo studies, the combination of rapamycin with trabectedin downregulated HMGA1 expression and stabilized tumor growth of 3-methylcholantrene-induced sarcoma-like models. HMGA1 is an adverse prognostic factor for trabectedin treatment in advanced STS. HMGA1 silencing increases trabectedin efficacy, in part by modulating the mTOR signaling pathway. Trabectedin plus mTOR inhibitors are active in preclinical models of sarcoma, downregulating HMGA1 expression levels and stabilizing tumor growth.
There is an urgent need to improve conventional cancer‐treatments by preventing detrimental side effects, cancer recurrence and metastases. Recent studies have shown that presence of senescent cells in tissues treated with chemo‐ or radiotherapy can be used to predict the effectiveness of cancer treatment. However, although the accumulation of senescent cells is one of the hallmarks of cancer, surprisingly little progress has been made in development of strategies for their detection in vivo. To address a lack of detection tools, we developed a biocompatible, injectable organic nanoprobe (NanoJagg), which is selectively taken up by senescent cells and accumulates in the lysosomes. The NanoJagg probe is obtained by self‐assembly of indocyanine green (ICG) dimers using a scalable manufacturing process and characterized by a unique spectral signature suitable for both photoacoustic tomography (PAT) and fluorescence imaging. In vitro, ex vivo and in vivo studies all indicate that NanoJaggs are a clinically translatable probe for detection of senescence and their PAT signal makes them suitable for longitudinal monitoring of the senescence burden in solid tumors after chemotherapy or radiotherapy.
Extensive research into green technologies is driven by the worldwide push for eco‐friendly materials and energy solutions. The focus is on synergies that prioritize sustainability and environmental benefits. This study explores the potential of abundant, non‐toxic, and sustainable resources such as paper, lignin‐enriched paper, and cork for producing laser‐induced graphene (LIG) supercapacitor electrodes with improved capacitance. A single‐step methodology using a CO2 laser system is developed for fabricating these electrodes under ambient conditions, providing an environmentally friendly alternative to conventional carbon sources. The resulting green micro‐supercapacitors (MSCs) achieve impressive areal capacitance (≈7–10 mF cm⁻²) and power and energy densities (≈4 μW cm‐2 and ≈0.77 µWh cm⁻² at 0.01 mA cm⁻²). Stability tests conducted over 5000 charge–discharge cycles demonstrate a capacitance retention of ≈80–85%, highlighting the device durability. These LIG‐based devices offer versatility, allowing voltage output adjustment through stacked and sandwich MSCs configurations (parallel or series), suitable for various large‐scale applications. This study demonstrates that it is possible to create high‐quality energy storage devices based on biodegradable materials. This development can lead to progress in renewable energy and off‐grid technology, as well as a reduction in electronic waste.
The present study explored the utilization of Rugulopteryx okamurae (RO), an invasive brown seaweed, as a renewable raw material for plastic materials based on biopolymer blends. The goal of this study was to improve the previously observed poor mechanical properties of materials based on single biopolymer RO. To enhance these properties, two polymers with distinct hydrophobicities were incorporated into the formulation of different blends: hydrophobic polycaprolactone (PCL) and hydrophilic acylated soy protein isolate (SPIa). SPIa was derived from soy protein through a chemical modification process, introducing hydrophilic carboxyl groups. The addition of PCL significantly strengthened the blend, increasing the storage modulus (E′1 Hz) from ~ 110 to ~ 250 MPa. Conversely, SPIa incorporation resulted in softening, with E′ values around 40 MPa. Both additives enhanced deformability proportionally to their concentrations, with SPIa exhibiting notably higher deformability, reaching a maximum deformation of ~ 23% for a RO/SPIa ratio of 25/75. In summary, the study demonstrates the feasibility of producing environmentally friendly blend materials based on RO, tailored for specific applications by incorporating suitable additives into the formulation. Therefore, PCL is recommended for applications susceptible to moisture effects, such as packaging, while SPIa is suggested for highly absorbent applications such as personal care or horticulture.
Background Levodopa‐induced dyskinesias (LID) are frequent in Parkinson's disease (PD). Objective To analyze the change in the frequency of LID over time, identify LID related factors, and characterize how LID impact on patients’ quality of life (QoL). Patients and Methods PD patients from the 5‐year follow‐up COPPADIS cohort were included. LID were defined as a non‐zero score in the item “Time spent with dyskinesia” of the Unified Parkinson's Disease Rating Scale—part IV (UPDRS‐IV). The UPDRS‐IV was applied at baseline (V0) and annually for 5 years. The 39‐item Parkinson's disease Questionnaire Summary Index (PQ‐39SI) was used to asses QoL. Results The frequency of LID at V0 in 672 PD patients (62.4 ± 8.9 years old; 60.1% males) with a mean disease duration of 5.5 ± 4.3 years was 18.9% (127/672) and increased progressively to 42.6% (185/434) at 5‐year follow‐up (V5). The frequency of disabling LID, painful LID, and morning dystonia increased from 6.9%, 3.3%, and 10.6% at V0 to 17.3%, 5.5%, and 24% at V5, respectively. Significant independent factors associated with LID ( P < 0.05) were a longer disease duration and time under levodopa treatment, a higher dose of levodopa, a lower weight and dose of dopamine agonist, pain severity and the presence of motor fluctuations. LID at V0 ( β = 0.073; P = 0.027; R ² = 0.62) and to develop disabling LID at V5 ( β = 0.088; P = 0.009; R ² = 0.73) were independently associated with a higher score on the PDQ‐39SI. Conclusion LID are frequent in PD patients. A higher dose of levodopa and lower weight were factors associated to LID. LID significantly impact QoL.
The E3 SUMO ligase PIAS2 is expressed at high levels in differentiated papillary thyroid carcinomas but at low levels in anaplastic thyroid carcinomas (ATC), an undifferentiated cancer with high mortality. We show here that depletion of the PIAS2 beta isoform with a transcribed double-stranded RNA–directed RNA interference (PIAS2b-dsRNAi) specifically inhibits growth of ATC cell lines and patient primary cultures in vitro and of orthotopic patient-derived xenografts (oPDX) in vivo. Critically, PIAS2b-dsRNAi does not affect growth of normal or non-anaplastic thyroid tumor cultures (differentiated carcinoma, benign lesions) or cell lines. PIAS2b-dsRNAi also has an anti-cancer effect on other anaplastic human cancers (pancreas, lung, and gastric). Mechanistically, PIAS2b is required for proper mitotic spindle and centrosome assembly, and it is a dosage-sensitive protein in ATC. PIAS2b depletion promotes mitotic catastrophe at prophase. High-throughput proteomics reveals the proteasome (PSMC5) and spindle cytoskeleton (TUBB3) to be direct targets of PIAS2b SUMOylation at mitotic initiation. These results identify PIAS2b-dsRNAi as a promising therapy for ATC and other aggressive anaplastic carcinomas.
Microkinetic modeling is a computational tool that allows simulating the evolution of the concentration of catalytically relevant species with time, providing a description of the catalytic system closer to the experimental. Microkinetic models have been mainly applied in organometallic catalysis as a means for validating mechanistic proposals by comparing experimental and computed rates and concentrations at a given time. However, this tool becomes very useful when studying complicated reaction mechanisms, aiding in identifying the catalyst resting state, optimizing reaction conditions, or improving the catalyst design. In this Concept, we focus on these applications of microkinetic modeling through the discussion of some selected examples. In addition, we also point out some of the challenges and limitations we may face when building microkinetic models, which may explain why they are still underused.
Kochen–Specker contextuality is a fundamental feature of quantum mechanics and a crucial resource for quantum computational advantage and reduction of communication complexity. Its presence is witnessed in empirical data by the violation of noncontextuality inequalities. However, all known noncontextuality inequalities corresponding to facets of noncontextual polytopes are either Bell inequalities or refer to cyclic or state-independent contextuality scenarios. We introduce a general method for lifting noncontextuality inequalities, deriving facets of noncontextual polytopes for more complex scenarios from known facets of simpler subscenarios. Concretely, starting from an arbitrary scenario, the addition of a new measurement or a new outcome preserves the facet-defining nature of any noncontextuality inequality. This extends the results of Pironio [J. Math. Phys. 46, 062112 (2005)] from Bell nonlocality scenarios to contextuality scenarios, unifying liftings of Bell and noncontextuality inequalities. Our method produces facet-defining noncontextuality inequalities in all scenarios with contextual correlations, and we present examples of facet-defining noncontextuality inequalities for scenarios where no examples were known. Our results shed light on the structure of noncontextuality polytopes and the relationship between such polytopes across different scenarios.
Equilibrium particle orientation ( α ) is obtained by setting the summation of gravitational ( g ), electrohydrodynamic ( h ) and electrostatic ( e ) torques to zero. The orientation is found to be a function of frequency and voltage of the applied field.
The aim of the present study was to analyze how family relationships changed during the COVID-19 pandemic and to determine whether the health crisis modified the association between family dimensions and emerging adult children’s mental health. A large sample of 1732 emerging adults was recruited at two different moments. In 2015, 755 emerging adults were recruited, 201 from campus A (sample 1) and 554 from campus B (sample 2). In 2020, a new sample was recruited and 977 emerging adults completed the questionnaire, 198 from campus A (sample 1 / “Pre-pandemic sample”, recruited before the lockdown) and 779 from campus B (sample 2 / “COVID-19 sample” / recruited after the lockdown. The results reveal that the COVID-19 sample of emerging adults perceived poorer parent-child relationships (lower parental involvement and warmth) and reported poorer mental health (lower flourishing and higher psychological distress) than their counterparts in Cohort 1. For their part, the Pre-pandemic sample reported higher levels of psychological distress than their counterparts in Cohort 1. In all samples (Cohort 1 and Cohort 2, both Pre-pandemic and COVID-19), parenting functions were positively associated with children’s flourishing and negatively associated with their psychological distress. However, these associations were stronger in Cohort 2 than in Cohort 1, both when assessed before and when assessed during the pandemic. The results of the study support the increasingly important role played by the family as a protective factor for mental health, even in stressful situations when family relationships tend to deteriorate. Study limitations include the use of a sample composed mainly of young emerging adult university students. Future studies should strive to include more emerging adults from the entire age range encompassed by emerging adulthood, as well as members of the non-university-going emerging adult population. Investing in public programs focused on family functions during emerging adulthood is an essential strategy for protecting and improving young adults’ mental health and promoting positive family relationships in stressful situations.
Concentration-Polarization Electroosmosis (CPEO) refers to steady-state electroosmotic flows around charged dielectric micro-particles induced by low-frequency AC electric fields. Recently, these flows were shown to cause repulsion of colloidal particles from...
Background Some parasites use olfactory cues to detect their hosts and, since bacterial symbionts are partially responsible for animal odours, they could influence host parasitism. By autoclaving nest materials of hoopoe (Upupa epops) nests before reproduction started, we explored the hypothetical links between host-associated bacteria, volatiles and parasitism. During the nestling stage, we (i) estimated the level of ectoparasitism by chewing lice (Suborder Mallophaga) in adult hoopoe females and by Carnus haemapterus flies in nestlings, and (ii) characterized microbial communities and volatile profiles of nest environments (nest material and nest cavity, respectively) and uropygial secretions. Results Experimental nests had less diverse bacterial communities and more diverse volatile profiles than control nests, while occupants experienced lower intensity of parasitism in experimental than in control nests. The experiment also affected beta diversity of the microbial communities of nest material and of the volatiles of the nestling uropygial secretions. Moreover, microbial communities of uropygial secretions and of nest materials covaried with their volatile profiles, while the volatile profile of the bird secretions explained nest volatile profile. Finally, a subset of the volatiles and bacteria detected in the nest material and uropygial secretions were associated with the ectoparasitism intensity of both adult females and nestlings, and with fledging success. Conclusions These results show that a component of animal odours is linked with the microbial communities of the host and its reproductive environment, and emphasize that the associations between bacteria, ectoparasitism and reproductive success are partially mediated by volatiles of bacterial origin. Future work should focus on mechanisms underlying the detected patterns.
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David Leon
  • Plant Biology and Ecology
Manuel Pérez-Ruiz
  • Aerospace Engineering and Fluid Mechanics
Isidoro Caraballo
  • Pharmacy and Pharmaceutical Technology
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