Universidad de La Laguna
  • La Laguna, Santa Cruz de Tenerife, Spain
Recent publications
The development of sustainable analytical sample preparation procedures based on novel extraction techniques has become a significant research trend nowadays, clearly driven by current environmental concerns. Advances in extraction methods have occurred in parallel with the introduction of novel materials as extraction sorbents or solvents. These novel extractant materials can be labeled as “green” if at least one of the following statements is ensured: the material proceeds from a renewable source, its preparation is sustainable, and/or its use reduces the amount of hazardous chemicals needed during the extraction and/or the wastes generated. The aim of this book chapter is to give an overview on the preparation and use of green sorbents when used mostly as extractant materials in analytical sample preparation methods, and in less extent in chromatography, with emphasis on their sustainability, and a critical discussion of strengths and weaknesses of these materials in such techniques.
Introduction DNA methylation studies have associated methylation levels at different CpG sites or genomic regions with lung function. Moreover, genetic ancestry has been associated with lung function in Latinos. However, no epigenome-wide association study (EWAS) of lung function has been performed in this population. Here, we aimed to identify DNA methylation patterns associated with lung function in pediatric asthma among Latinos. Results We conducted an EWAS in whole blood from 250 Puerto Rican and 148 Mexican American children and young adults with asthma. A total of five CpGs exceeded the genome-wide significance threshold of p = 1.17 × 10 ⁻⁷ in the combined analyses from Puerto Ricans and Mexican Americans: cg06035600 ( MAP3K6 , p = 6.13 × 10 ⁻⁸ ) showed significant association with pre-bronchodilator Tiffeneau–Pinelli index, the probes cg00914963 ( TBC1D16 , p = 1.04 × 10 ⁻⁷ ), cg16405908 ( MRGPRE , p = 2.05 × 10 ⁻⁸ ) , and cg07428101 ( MUC2 , p = 5.02 × 10 ⁻⁹ ) were associated with post-bronchodilator forced vital capacity (FVC), and cg20515679 ( KCNJ6 ) with post-bronchodilator Tiffeneau–Pinelli index ( p = 1.13 × 10 ⁻⁸ ). However, these markers did not show significant associations in publicly available data from Europeans ( p > 0.05). A methylation quantitative trait loci analysis revealed that methylation levels at these CpG sites were regulated by genetic variation in Latinos and the Biobank-based Integrative Omics Studies (BIOS) consortium. Additionally, two differentially methylated regions in REXOC and AURKC were associated with pre-bronchodilator Tiffeneau–Pinelli index (adjusted p < 0.05) in Puerto Ricans and Mexican Americans. Moreover, we replicated some of the previous differentially methylated signals associated with lung function in non-Latino populations. Conclusions We replicated previous associations of epigenetic markers with lung function in whole blood and identified novel population-specific associations shared among Latino subgroups.
Red-emitting phosphors play a vital role in reinforcing the quality of phosphor-converted white light-emitting diodes. Unfortunately, concentration quenching and unsatisfied thermal stability are still the inevitable shortcomings of the red-emitting phosphors. Herein, we utilized phase transition to simultaneously tailor the concentration quenching and thermal stability of Eu³⁺-activated NaYbF4 (NaYbF4:xEu³⁺) nanoparticles, in order to overcome these limitations. With the increasing doping level, the resultant samples undergo a phase transition from cubic to hexagonal phase. Notably, the optimal doping content for Eu³⁺ in the NaYbF4 nanoparticles with cubic phase is 30 mol%. However, when the phase transition occurs, the concentration quenching takes place at a much higher doping concentration, i.e. the optimum content of Eu³⁺ in the structure is increased to about 80 mol%. Moreover, with elevating the Eu³⁺ content, the local coordination environment of Eu³⁺ in the NaYbF4 host lattice is changed from inversion (centrosymmetric) to non-inversion symmetry (non-centrosymmetric), which is further confirmed by the theoretical calculation results via Judd-Oflet theory. Furthermore, compared with cubic samples, the hexagonal NaYbF4:0.8Eu³⁺ nanoparticles show improved thermal stability. Importantly, utilizing hexagonal NaYbF4:0.8Eu³⁺ nanoparticles, a designed white light-emitting diode emits warm white light, with desired color coordinates (0.398,0.374), high color rendering index (86.3), and low correlated color temperature (3537 K). Besides, NaYbF4:xEu³⁺ nanoparticles and their flexible polydimethylsiloxane films exhibit potential applications in high-temperature optical anti-counterfeiting. This work may support a new perspective for tailoring the concentration quenching and thermal stability of various phosphors.
Biomass-derived chemical platforms such as 5-hydroxymethylfurfural (5-HMF) can offer straightforward access to new value-added products. The presence of an aldehyde and hydroxymethyl functional groups in this molecule are interesting structural motifs to explore the synthesis of new bioactive compounds. In this contribution, a strategy to quickly and efficiently synthesize nitrovinylfurans starting from 5-HMF under greener conditions is described and the antiproliferative activity of the synthesized compounds evaluated. 5-HMF obtained by microwave-assisted saturated biphasic dehydration from fructose was used to produce furaldehyde derivatives. Next, through a nitroaldolic condensation, the desired nitrovinylfurans were generated using efficient heating sources, ultrasound, or a non-microwave instant heating reactor, under solvent-free conditions. Most of the newly synthesized compounds showed growth inhibition when assayed for their in vitro antiproliferative activity against six cancer cell lines (A549, HBL-100, HeLa, SW1573, T-47D, and WiDr), with lower toxicity on the human macrophage-like cells (THP-1). Our strategy allowed the rapid identification of nitrovinylfurans 16, 17, 19, and 20 as future candidates for the development of new selective anticancer drugs.
Introduction There is still an undiscovered territory about the sequelae and lung ultrasound (LUS) findings after SARS-CoV2 acute infection. This study aims to investigate the post-COVID period from a clinical, psychosocial, and radiological point of view, analyze LUS on COVID-19 follow-up and detect whether these outcomes are related to the patient situation. Methods We conducted an observational study on patients diagnosed with SARS-CoV2 pneumonia and admitted to the University Hospital of La Candelaria (Tenerife, Spain) from 1st March to 31st August 2020. We performed a descriptive analysis on post-COVID manifestations, LUS score, health-related quality of life measured through the Euroqol 5D-5L questionnaire, and lung function parameters on follow-up, and we compared these variables to the outcomes during the hospital admission. Results 77 patients were included; the mean age was 57 years and the follow-up mean time from hospital discharge was 16 weeks. 87% of the cases had symptoms on follow-up, the most common was dyspnea (65%); these manifestations were more frequent in females (p = 0,015). 76,5% of the cases had lung aeration alteration in LUS on follow-up; lower PaO2/FiO2 and greater CRP and IL-6 levels on admission were related to LUS score ≥1. Conclusions Almost 90% of the patients had persistent symptoms after 16 weeks of hospital discharge due to COVID-19, the most common manifestation presented was dyspnea. Altered lung aeration pattern in LUS was observed on more than 70% of the patients on follow-up.
The compound-specific δ¹³C values of n-alkanes from pastoralist winter campsites in Mongolia have great potential to reconstruct dietary seasonality of livestock and local vegetation. We analysed leaf wax n-alkanes and their carbon isotope ratios in common fodder plants (Artemisia mongolica, Chenopodium album, Elymus dahuricus, Elymus sibiricus and Stipa sibirica) fed to domesticates during the winter months, and also in topsoils (0–8 cm) from four livestock corrals in northern and southern Mongolia. n-Alkanes identified in fresh plant parts reflect signatures with mean δ¹³C stable isotope values of individual n-alkanes typical for C3 plants (−34.1‰). Plants from forest- and desert-steppe exhibit similar mean n-alkane δ¹³C values but significantly wider isotopic variation in the desert steppe flora. The non-anthropogenic control samples exhibit δ¹³C mean values significantly higher from that of dung deposits and fresh plants for the same regions. Our data support previous research that n-alkanes profiles and their carbon isotopic values vary depending on the local vegetation and environment, while simultaneously demonstrating how anthropogenic activity, such as corralling of livestock, is recorded in the n-alkane of domesticates dung validating the use of biomarker studies in pastoralist archaeological contexts for distinguishing seasonal foddering, local environmental data and to an extent grazing habitats.
This paper deals with innovative renewable energy (RE) - powered seawater reverse osmosis (SWRO) plants based on tidal range/PhotoVoltaic (PV) systems as a hybrid technology with interesting prospects to promote the RE desalination at medium to large capacity ranges. Key features to enhance solar PV with tidal range energy are the good temporary complementarity of both options and the predictable water production pattern that the tidal range plant allows, along with ensuring water production at night. Once the basic sizing of a power plant referred to a 20 MW turbine is conducted, the sensitivity analysis of main performance parameters of the hybrid solar/tidal desalination system is carried out through yearly simulations. With this analysis, an extension of the knowledge about the performance of hybrid tidal/solar desalination is gained in such a way that three useful design criteria are derived from the results: i) total investment cost per unitary water production, ii) energy consumed in desalination to total energy production, and iii) energy non-useful for desalination. Recommended designs are provided under each of these three criteria for given yearly freshwater demand with SWRO plants of 3.5 and 4.8 kWh/m³ of specific energy consumption. Results proves that off-grid SWRO desalination powered by hybrid tidal/PV systems in a favorable location achieves actual water production of one half of nominal production with adequate selection of design parameters. Recommended sizing of the energy generator for minimizing capital costs corresponds to 20 MW tidal/25–27 MWp PV per 12 MW of SWRO consumption. Additionally, in absence of realistic costs data, the recommended design criterion for the plant sizing relies on the ratio of energy used by the desalination plant to that produced by the hybrid tidal/PV generator. Results at an exemplary plant location show that 14.1 × 10⁶ m³/y of fresh water obtained with desalination consumption of 3.5 kWh/m³ needs 2.0 MW tidal/26.9 MWp PV. This energy system would produce 10 × 10⁶ m³/y considering 4.8 kWh/m³ of specific consumption.
In this paper we investigate a non-linear and non-local one dimensional transport equation under random perturbations on the real line. We first establish a local-in-time theory, i.e., existence, uniqueness and blow-up criterion for pathwise solutions in Sobolev spaces Hs with s>3. Thereafter, we give a picture of the long time behavior of the solutions based on the type of noise we consider. On one hand, we identify a family of noises such that blow-up can be prevented with probability 1, guaranteeing the existence and uniqueness of global solutions almost surely. On the other hand, in the particular linear noise case, we show that singularities occur in finite time with positive probability, and we derive lower bounds of these probabilities. To conclude, we introduce the notion of stability of exiting times and show that one cannot improve the stability of the exiting time and simultaneously improve the continuity of the dependence on initial data.
The ribosomal DNA (rDNA) array of Saccharomyces cerevisiae has served as a model to address chromosome organization. In cells arrested before anaphase (mid-M), the rDNA acquires a highly structured chromosomal organization referred to as the rDNA loop, whose length can double the cell diameter. Previous works established that complexes such as condensin and cohesin are essential to attain this structure. Here, we report that the rDNA loop adopts distinct presentations that arise as spatial adaptations to changes in the nuclear morphology triggered during mid-M arrests. Interestingly, the formation of the rDNA loop results in the appearance of a space under the loop (SUL) which is devoid of nuclear components yet colocalizes with the vacuole. We show that the rDNA-associated nuclear envelope (NE) often reshapes into a ladle to accommodate the vacuole in the SUL, with the nucleus becoming bilobed and doughnut-shaped. Finally, we demonstrate that the formation of the rDNA loop and the SUL require TORC1, membrane synthesis and functional vacuoles, yet is independent of nucleus–vacuole junctions and rDNA-NE tethering.
Sodium-glucose co-transporter-2 inhibitors (SGLT2i) provide cardiorenal protection. However, the molecular mechanisms remain poorly understood. We explored the impact of SGLT2i on Klotho, a kidney-derived protein with antiaging, renal-protective and heart-protective properties. A real world prospective observational study addressed the impact of initiating SGLT2i (canagliflozin, dapagliflozin, empagliflozin) or dipeptidyl peptidase-4 inhibitors (DPP4i) in patients with early diabetic kidney disease (DKD). Serum and urinary soluble Klotho, albuminuria and serum and urinary tumor necrosis factor-alpha (TNFa) were measured. The effect of SGLT2i on Klotho mRNA and protein was explored in vitro in kidney proximal tubular cells stressed with high glucose concentrations to simulate the diabetic milieu, albumin to simulate albuminuria, and the inflammatory cytokine TWEAK to simulate the inflammatory environment in DKD. Baseline urinary Klotho was negatively associated with albuminuria (r − 0.45, P < 0.001) and urinary TNFa (r − 0.40, P < 0.01). Both DPP4i and SGLT2i reduced HbA1c similarly, but only SGLT2i decreased eGFR, albuminuria and urinary TNFa and increased (P < 0.001) serum (5.2 %) and urinary Klotho (38.9 %). Changes in urinary TNFa (β − 0.53, P = 0.001) and albuminuria (β − 0.31, P < 0.05) were independently associated with changes in urinary Klotho (adjusted R² = 0.54, P < 0.001). Studies in renal tubular cells demonstrated that high glucose, albumin and TWEAK decreased Klotho mRNA expression and protein levels, an effect similarly prevented by SGLT2i. SGLT2i increase Klotho availability in type 2 diabetic patients with poorly controlled diabetes and early DKD, as well as in stressed tubular cells. This effect on Klotho may contribute to the kidney and heart protection afforded by SGLT2i.
Géza Alföldy (1935-2011) is considered as one of the most important epigraphists and historians of the Roman civilization of the late 20th century, known also as "Mommsen of our ages". His contribution is indispensable not only for the discipline of Roman epigraphy and social history, but also for the study of Roman religion. His intellectual roots in Hungary and the influence of the Hungarian scholarly tradition of the 1950's marked his interest in the study of Roman religion for a long period. In this study, the authors discuss the formation of Géza Alföldy and his contribution to the discipline through a wider academic and socio-historical context.
Rationale and objective Patients with chronic obstructive pulmonary disease (COPD), usually diagnosed after the 6th decade, frequently suffer from comorbidities. Whether COPD patients 50 years or younger (Young COPD) have similar comorbidities with the same frequency and mortality impact as aged-matched controls or older COPD patients is unknown. Methods We compared comorbidity number, prevalence and type in 3 groups of individuals with ≥ 10 pack-years of smoking: A Young ( ≤ 50 years) COPD group (n = 160), an age-balanced control group without airflow obstruction (n = 125), and Old (> 50 years) COPD group (n = 1860). We also compared survival between the young COPD and control subjects. Using Cox proportional model, we determined the comorbidities associated with mortality risk and generated Comorbidomes for the “Young” and “Old” COPD groups. Results The severity distribution by GOLD spirometric stages and BODE quartiles were similar between Young and Old COPD groups. After adjusting for age, sex, and pack-years, the prevalence of subjects with at least one comorbidity was 31% for controls, 77% for the Young, and 86% for older COPD patients. Compared to controls, “Young” COPDs’ had a nine-fold increased mortality risk (p < 0.0001). “Comorbidomes” differed between Young and Old COPD groups, with tuberculosis, substance use, and bipolar disorders being distinct comorbidities associated with increased mortality risk in the Young COPD group. Conclusions Young COPD patients carry a higher comorbidity prevalence and mortality risk compared to non-obstructed control subjects. Young COPD differed from older COPD patients by the behavioral-related comorbidities that increase their risk of premature death.
The current inhabitants of the Canary Islands have a unique genetic makeup in the European diversity landscape due to the existence of African footprints from recent admixture events, especially of North African components (> 20%). The underrepresentation of non-Europeans in genetic studies and the sizable North African ancestry, which is nearly absent from all existing catalogs of worldwide genetic diversity, justify the need to develop CIRdb, a population-specific reference catalog of natural genetic variation in the Canary Islanders. Based on array genotyping of the selected unrelated donors and comparisons against available datasets from European, sub-Saharan, and North African populations, we illustrate the intermediate genetic differentiation of Canary Islanders between Europeans and North Africans and the existence of within-population differences that are likely driven by genetic isolation. Here we describe the overall design and the methods that are being implemented to further develop CIRdb. This resource will help to strengthen the implementation of Precision Medicine in this population by contributing to increase the diversity in genetic studies. Among others, this will translate into improved ability to fine map disease genes and simplify the identification of causal variants and estimate the prevalence of unattended Mendelian diseases.
Background Colletotrichum gloeosporioides ES026, isolated as an endophytic fungal strain, was found to produce the important medicinal compound HuperzineA (HupA). In a genetic context, ES026 showed potential in elucidating the biosynthetic pathway of HupA. Methods and Results The ES026 strain was sequenced using de-novo Illumina sequencing methods in this study. Assembling the cleaned data resulted in 58,594,804bp, consisting of 404 scaffolds. The G + C mol % content of this genome was 52.53%. The genome progressive-alignment with other 4 Colletotrichum strains revealed that ES026 showed closer relation with 030206, SMCG1#C and Nara gc5. More than 60 putative biosynthetic clusters were predicted with the fungal version antiSMASH4.0 program. More than 33 types I polyketide-related biosynthetic gene clusters were distributed, containing PKS and PKS-NRPS (polyketide-nonribosomal peptides) hybrid gene clusters. Another 8 NRPS biosynthetic gene clusters were distributed among the genome of ES026. The prenyltransferases, probably involved in aromatic prenyl-compounds and terpenoid biosynthesis, were analyzed using bioinformatics tools like MEGA. Conclusion We predicted a new possible biosynthetic pathway for the HupA from the pipecolic acid, based on the published HupA biosynthesis proposed pathway, the biosynthesis and pipecolic acid-derived compounds. We hypothesize that a hybrid PKS-NRPS mega-enzyme was probably involved in the biosynthesis of HupA with the pipecolic acid, the building block of rapamycin, as a HupA precursor. The rapamycin is produced from a polyketide biosynthesis pathway, and the domain incorporating the pipecolic acid is studied.
Civility is formed by social norms that guide our behavior and allow us to interact appropriately with others. These norms affect everyone and are learned through the socialization process. However, in the same process, people also learn gender norms that dictate how men and women should behave, leading to gender stereotypes and differentiated behavioral characteristics. The purpose of this research is to examine the relationship between gender and civility, and how we react to those who behave uncivilly given their gender. The results of Study 1 (N = 153) showed that even in a fictional and gender-neutral society, uncivil behaviors were associated with stereotypically masculine characteristics, and those who behaved uncivilly were dehumanized. In Study 2 (N = 144), gender differences were observed in incivility. Women were harsher when facing uncivil transgressors than men, especially if the transgressor was another woman. Our findings support the notion that gender norms are applied to civility, leading those supposedly equal social norms to unequal perceptions and evaluations.
Testing Neanderthal behavioural hypotheses requires a spatial–temporal resolution to the level of a human single occupation episode. Yet, most of the behavioural data on Neanderthals has been obtained from coarsely dated, time-averaged contexts affected by the archaeological palimpsest effect and a diversity of postdepositional processes. This implies that time-resolved Neanderthal behaviour remains largely unknown. In this study, we performed archaeostratigraphic analysis on stratigraphic units ive, ivf, ivg, va, vb and vc from Abric del Pastor (Alcoi, Iberian Peninsula). Further, we isolated the archaeological remains associated with the resulting archaeostratigraphic unit and applied raw material, technological, use-wear, archaeozoological and spatial analyses. Our results show a low-density accumulation of remains from flintknapping, flint tool-use and animal processing around a hearth. These data provide a time-resolved human dimension to previous high-resolution environmental and pyrotechnological data on the same hearth, representing the first comprehensive characterisation of a Neanderthal single occupation episode. Our integrated, multidisciplinary method also contributes to advance our understanding of archaeological record formation processes.
Statins are effective sterol lowering agents with high amoebicidal activity. Nevertheless, due to their poor aqueous solubility, they remain underused especially in eye drop formulation. The aim of the present study is to develop Pitavastatin loaded nanoparticles suitable for ophthalmic administration and designed for the management of Acanthamoeba Keratitis. These nanocarriers are aimed to solve both the ophthalmic route-associated problems and the limited aqueous drug solubility issues of Pitavastatin. Nanoparticles were obtained by a nanoprecipitation-solvent displacement method and their amoebicidal activity was evaluated against four strains of Acanthamoeba: A. castellanii Neff, A. polyphaga, A. griffini and A. quina. In Acanthamoeba polyphaga, the effect of the present nanoparticles was investigated with respect to the microtubule distribution and several programmed cell death features. Nanoparticles were able to eliminate all the tested strains and Acanthamoeba polyphaga was determined to be the most resistance strain. Nanoparticles induced chromatin condensation, autophagic vacuoles and mitochondria dysfunction.
Samples of the carbonaceous asteroid Ryugu were brought to Earth by the Hayabusa2 spacecraft. We analyzed seventeen Ryugu samples measuring 1-8 mm. CO2-bearing water inclusions are present within a pyrrhotite crystal, indicating that Ryugu's parent asteroid formed in the outer Solar System. The samples contain low abundances of materials that formed at high temperatures, such as chondrules and Ca, Al-rich inclusions. The samples are rich in phyllosilicates and carbonates, which formed by aqueous alteration reactions at low temperature, high pH, and water/rock ratios < 1 (by mass). Less altered fragments contain olivine, pyroxene, amorphous silicates, calcite, and phosphide. Numerical simulations, based on the mineralogical and physical properties of the samples, indicate Ryugu's parent body formed ~ 2 million years after the beginning of Solar System formation.
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4,355 members
Marcos Colebrook
  • Department of Computer Science
Jose Luis González-Mora
  • Department of Basic Médical Science (sec. Physiology)
Serafin Corral
  • Department of Applied Economics and Quantitative Methods
Sara García Cuesta
  • Department of Sociology
Gundela Meyer
  • Department of Anatomy, Pathological Anatomy and Histology
Pabellón de Gobierno, C/ Molinos de Agua s/n., 38200, La Laguna, Santa Cruz de Tenerife, Spain
Head of institution
Rosa Mª Aguilar Chinea
(+34) 922 31 90 00/01