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"Ayala, Alejandro"
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Assessing the Novel Mixed Tutton Salts K2Mn0.03Ni0.97(SO4)2(H2O)6 and K2Mn0.18Cu0.82(SO4)2(H2O)6 for Thermochemical Heat Storage Applications: An Experimental–Theoretical Study
In this paper, novel mixed Tutton salts with the chemical formulas K2Mn0.03Ni0.97(SO4)2(H2O)6 and K2Mn0.18Cu0.82(SO4)2(H2O)6 were synthesized and studied as compounds for thermochemical heat storage potential. The crystallographic structures of single crystals were determined by X-ray diffraction. Additionally, a comprehensive computational study, based on density functional theory (DFT) calculations and Hirshfeld surface analysis, was performed to calculate structural, electronic, and thermodynamic properties of the coordination complexes [MII(H2O)6]2+ (MII = Mn, Ni, and Cu), as well as to investigate intermolecular interactions and voids in the framework. The axial compressions relative to octahedral coordination geometry observed in the crystal structures were correlated and elucidated using DFT investigations regarding Jahn–Teller effects arising from complexes with different spin multiplicities. The spatial distributions of the frontier molecular orbital and spin densities, as well as energy gaps, provided further insights into the stability of these complexes. Thermogravimetry, differential thermal analysis, and differential scanning calorimetry techniques were also applied to identify the thermal stability and physicochemical properties of the mixed crystals. Values of dehydration enthalpy and storage energy density per volume were also estimated. The two mixed sulfate hydrates reported here have low dehydration temperatures and high energy densities. Both have promising thermal properties for residential heat storage systems, superior to the Tutton salts previously reported.
Journal Article
Exploring the Potential of a New Nickel(II):Phenanthroline Complex with L-isoleucine as an Antitumor Agent: Design, Crystal Structure, Spectroscopic Characterization, and Theoretical Insights
This study presents the synthesis, physicochemical characterization, and biological evaluation of a novel ternary nickel(II) complex with isoleucine and 1,10-phenanthroline ligands, [Ni(Phen)(Ile)2]∙6H2O, designed as a potential antitumor agent. Single-crystal X-ray diffraction revealed a monoclinic structure (C2-space group) with an octahedral Ni(II) coordination involving Phen and Ile ligands. A Hirshfeld surface analysis highlighted intermolecular interactions stabilizing the crystal lattice, with hydrogen bonds (H···H and O···H/H···O) dominating (99.1% of contacts). Density functional theory (DFT) calculations, including solvation effects (in water and methanol), demonstrated strong agreement with the experimental geometric parameters and revealed higher affinity to the water solvent. The electronic properties of the complex, such as HOMO−LUMO gaps (3.20–4.26 eV) and electrophilicity (4.54–5.88 eV), indicated a charge-transfer potential suitable for biological applications through interactions with biomolecules. Raman and infrared spectroscopic studies showed vibrational modes associated with Ni–N/O bonds and ligand-specific deformations, with solvation-induced shifts observed. A study using ultraviolet–visible–near-infrared absorption spectroscopy demonstrated that the complex remains stable in solution. In vitro cytotoxicity assays against MCF-7 (breast adenocarcinoma) and HCT-116 (colorectal carcinoma) cells showed dose-dependent activity, achieving 47.6% and 65.3% viability reduction at 100 μM (48 h), respectively, with lower toxicity to non-tumor lung fibroblasts (GM07492A, 39.8%). Supporting the experimental data, we performed computational modeling to examine the pharmacokinetic profile, with particular focus on the absorption, distribution, metabolism, and excretion properties and drug-likeness potential.
Journal Article
Comparison of qualitative and quantitative impedance tomography image reconstruction methods
In recent years, electrical impedance tomography (EIT) has gained significant relevance in research, agriculture, and biomedicine. To meet the specific needs of each application, specialized systems and algorithms have been developed. Evaluating their performance is crucial for their improvement and effective application. This work presents a methodology for the evaluation of EIT systems using mathematical tools such as the Pearson Correlation Coefficient (PCC) and Root Mean Square Error (RMSE). These metrics quantify the similarity and accuracy of qualitative and quantitative reconstruction algorithms using synthetic data generated in COMSOL Multiphysics. The results show that the PCC ranges from 0.8166 to 0.9686, while the RMSE varies between 0.12456 and 0.14827, depending on the electrical properties of the material and the domain. This methodology establishes a framework for integrating new evaluation tools, contributing to the advancement of EIT systems and reconstruction algorithms.
Journal Article
Estimate for the Neutrino Magnetic Moment from Pulsar Kick Velocities Induced at the Birth of Strange Quark Matter Neutron Stars
We estimate the magnetic moment of electron neutrinos by computing the neutrino chirality flip rate that can occur in the core of a strange quark matter neutron star at birth. We show that this process allows neutrinos to anisotropically escape, thus inducing the star kick velocity. Although the flip from left- to right-handed neutrinos is assumed to happen in equilibrium, the no-go theorem does not apply because right-handed neutrinos do not interact with matter and the reverse process does not happen, producing the loss of detailed balance. For simplicity, we model the star core as consisting of strange quark matter. We find that even when the energy released in right-handed neutrinos is a small fraction of the total energy released in left-handed neutrinos, the process describes kick velocities for natal conditions, which are consistent with the observed ones and span the correct range of radii, temperatures and chemical potentials for typical magnetic field intensities. The neutrino magnetic moment is estimated to be μν∼3.6×10−18μB, where μB is the Bohr magneton. This value is more stringent than the bound found for massive neutrinos in a minimal extension of the standard model.
Journal Article
Management of Soil-Borne Fungi and Root-Knot Nematodes in Cucurbits through Breeding for Resistance and Grafting
Soil-borne pathogenic fungi (SBPF) and root-knot nematodes (RKN) co-exist in the rhizosphere and are major pathogens causing root diseases in cucurbits. Current knowledge on soil-borne pathogens of cucurbit crops grown under protected cultivation, their host-pathogen interactions, and mechanisms of resistance has been reviewed. Plant resistance is an effective and sustainable method to control soil-borne diseases and the available resistant cultivars and rootstocks to key soil-borne pathogens are reported. The importance of proper pathogen diagnosis in the right choice of cultivar or rootstock is highlighted because of the specificity in the response of the cucurbit crops to fungal and nematode species and races. Plants protect themselves through common mechanisms of resistance against SBPF and RKN including hardening of their cell walls, pathogenesis-related (PR) proteins, and production of antimicrobial molecules. The activity of some enzymes, such as peroxidases and phenylalanine lyase, is increased after pathogen infection and is higher on SBPF and RKN resistant than susceptible cucurbits. Plant hormones such as salicylic acid, jasmonic acid, and ethylene are involved in the response of cucurbits to SBPF. Most mechanisms of resistance to RKN affect post-infection development of the nematode, which results in a delay or disruption of the life cycle. Traditional and biotechnological tools used for breeding for resistance in cucurbits are described. Grafting is an effective non-host resistance method to control primarily Fusarium wilt but not to control RKN. However, new rootstocks with resistance to both pathogens have been developed recently and their effects on fruit quality and yield stability need additional studies. The impact of grafting on yield in pathogen-infested soils is discussed.
Journal Article
Benefit of dual-chamber pacing with Closed Loop Stimulation in tilt-induced cardio-inhibitory reflex syncope (BIOSync trial): study protocol for a randomized controlled trial
Background
The efficacy of dual-chamber cardiac pacing in neuro-mediated reflex syncope with a cardio-inhibitory response to the Tilt-Table test (TT) has not been definitively assessed so far. The lack of reproducibility of results from previous studies may be partially explained by discrepancies in subject selection and some weaknesses in design and methods. The European Society of Cardiology (ESC) has set a class IIb indication to pacemaker implantation in this population recommending further research.
Methods/design
The BIOSync study is a multicenter, patient- and outcome-assessor-blind, randomized, parallel-arm, placebo-controlled trial with the objective of assessing the clinical benefit of cardiac pacing in patients with frequently recurrent reflex syncope, suspected (but not proven) to be triggered by asystolic pauses as showing a VASIS 2B response to the TT (>3-s pause regardless of blood pressure drop). The primary and secondary endpoints are time to first post-implantation recurrence of syncope or the combination of pre-syncope or syncope, respectively. One hundred and twenty-eight consenting patients will be 1:1 randomized to dual-chamber cardiac pacing ‘on’ or ‘off’ after pacemaker implantation, and followed up until the first adjudicated primary endpoint event for a maximum of 2 years. The so-called Closed Loop Stimulation function on top of dual-chamber pacing is the pacing mode selected in the study active arm. Participating patients are asked to self-report syncopal symptoms at least every 3 months with self-administered questionnaires addressed to an independent Adjudication Committee. Patients and members of the Adjudicating Committee are blinded to randomization. The study is designed to detect a 40% relative reduction in the 2-year incidence of syncopal recurrences with 80% statistical power.
Discussion
The BIOSync study is designed to definitively assess the benefit of pacing against placebo in reflex syncope patients with a cardio-inhibitory response to the TT. The study will also provide important information on the efficiency of the TT in appropriately selecting reflex syncope patients for cardiac pacing.
Trial registration
ClinicalTrials.gov, identifier:
NCT02324920
(27 October 2016, date last accessed).
Journal Article
A workflow to integrate operational and embodied aspects when implementing Life Cycle Sustainability Assessment in Building Information Modelling
The existing environmental crisis demands increased efforts to design more sustainable buildings, which means the simultaneous balance between environmental preservation, economic growth, and social well-being. This challenging objective requires holistic methods that enable a comprehensive, multi-dimension, and quantitative approach such as allows the Life Cycle Sustainability Assessment (LCSA). In addition, the existing context of digital transformation in the construction and building sector is increasing the use of digital tools based on the BIM methodology to support the assessment process and integrating more dimensions to guide decision-making. The present work presents a workflow that enables the calculation of the LCSA including operational and embodied aspects. The workflow proposes the building elements that should be included in the BIM model to enable the exchange of information. The workflow is focused on the Spanish context and includes the use of Revit (as BIM modeler), Dynamo (as LCSA tool), Cypetherm (as the energy demand calculator). The proposed workflow enables us to compare different design options and building materials without much effort. The study includes findings and recommendations to reduce the effort when implementing the LCSA at the early design stages.
Journal Article
Hospital volume and outcomes of surgical repair in type A acute aortic dissection: A nationwide cohort study
Over the last decade, the number of patients treated with open repair for TAAAD in Taiwan has dramatically increased. This study aims to assess the hospital-volume relationship with surgical outcomes of type A acute aortic dissection (TAAAD) across hospitals in Taiwan.
Using the Taiwan National Health Insurance (NHI) Research Database (NHIRD), we include only the patients who underwent first open repair for TAAAD from 01/01/2005, to 31/12/2020, in Taiwan. A total of 8,059 patients in 77 hospitals were eligible for the analysis. Hospitals were categorized based on their 16-year cumulative volume of TAAAD open repair surgeries, and patients were grouped into quartiles accordingly.
Ascending aortic replacement (55.7%) and partial/total arch replacement (38.8%) were the most common methods of open aortic repair. In-hospital mortality was 22% and decreased from 28% in 2005 to 20% in 2020. Greater volume (per 5 annual surgeries) was associated with lower risks of in-hospital mortality (odd ratio 0.90, 95% confidence interval [CI] 0.87-0.92) and mortality after discharge (hazard ratio 0.97, 95% CI 0.95-0.99).
Operative volume inversely correlates to in-hospital mortality and postoperative complications. The volume-outcome effect extends after discharge and reflects better long-term survival. Hospital referral to high-volume centers should be considered in patients needing complex open repair for TAAAD.
Journal Article
Morphology, Chemical Characterization and Sources of Microplastics in a Coastal City in the Equatorial Zone with Diverse Anthropogenic Activities (Fortaleza city, Brazil)
The aim of the present study was to perform morphological and chemical characterizations of microplastics (MPs) found in seawater samples from the coast of the city of Fortaleza (CE) using Fourier-transform infrared (FTIR) spectroscopy, Raman spectroscopy and differential scanning calorimetry (DSC). Sampling was performed using a neuston sampler. MPs were separated based on the difference in density. MPs with varied morphologies were found. Fibers and fragments were the most abundant (57% and 36.2%, respectively). FTIR, Raman spectroscopy and DSC confirmed the presence of polyurethane and alkyd resin, polyethylene, polypropylene, polystyrene, polyamide blends, thermoplastic rubber and polyester fibers. The main sources of MPs and their relative contribution were fishing activities, food packaging and household products with 55.1%, household laundry with 27.2%, wear of surface coatings with 10.0% and wear of automobile tires with 7.6%. As a result, polyethylene, polypropylene, polystyrene and polyamide are believed to enter the marine environment mainly through fishing activities and debris from food packaging, polyester mainly through domestic sewage contaminated by washing clothes fibers, polyurethane and alkyd resin from the abrasive wear of surface coatings, as well as rubber particles from the wear of the automobile tires. Thus, one may infer that the main sources of MPs in the marine environment on the coast of Fortaleza are anthropogenic activities. Additionally, there is less information on blends and weathered MPs in commercial polymer databases. Therefore, the MP spectra obtained in this study can serve as a database to compare and characterize these more complex MPs.
Journal Article