Oceans are essentially an electrolyte solution. The experimental study of physical and chemical processes occurring in oceans remains challenging, so molecular dynamics simulations may be of great help. We have recently demonstrated that simulations using a state-of-the-art force field can accurately describe the thermophysical properties of seawater by employing a detailed chemical model of the solution.
View Article and Find Full Text PDFThe physical stability, molecular mobility, and appearance of nanocrystalline resveratrol in a polyvinylpyrrolidone (PVP) matrix were investigated. Two formulations with resveratrol loadings of 30% and 50% were prepared and characterized using powder X-ray diffraction (PXRD) and time-domain nuclear magnetic resonance (TD-NMR). Samples were studied over time (up to 300 days post-preparation), across temperatures (80-300 K), and under varying humidity conditions (0% and 75% relative humidity).
View Article and Find Full Text PDFWeather and soil water dictate farm operations such as irrigation scheduling. Low-cost and open-source agricultural monitoring stations are an emerging alternative to commercially available monitoring stations because they are often built from components using open-source, do-it-yourself (DIY) platforms and technologies. For irrigation management in an experimental vineyard located in Quiroga (Lugo, Spain), we faced the challenge of installing a low-cost environmental and soil parameter monitoring station composed of several nodes measuring air temperature and relative humidity, soil temperature, soil matric potential, and soil water content.
View Article and Find Full Text PDFObjective: To explore the association of maternal characteristics, oxygenation, and mechanical ventilatory parameters with fetal and neonatal outcomes.
Methods: The present study was a multicenter, binational (Argentina/Colombia), prospective, cohort study, conducted in 21 intensive care units (ICUs) and including pregnant or postpartum patients with COVID-19 pneumonia requiring advanced respiratory support and their fetuses/neonates. Advanced respiratory support was defined as high-flow nasal cannula (HFNC), non-invasive ventilation (NIV) or invasive mechanical ventilation (IMV).
J Phys Chem C Nanomater Interfaces
June 2024
Dion-Jacobson type materials have recently emerged as a new structural family of oxide ion conductors, materials important for applications in a variety of electrochemical devices. While some attempts to improve their ionic conductivity have been reported, a detailed understanding of the underlying oxide ion diffusion mechanisms in these materials is still missing. To explore the structure-property relationships leading to the favorable properties, we carried out molecular dynamics simulations of oxide ion diffusion in CsBiTiNbO.
View Article and Find Full Text PDFThis work presents new experimental viscosity and density data for aromatic and polyaromatic compounds in binary and ternary pyrene, 1-methylnaphthalene, and dodecane mixtures. The lack of experimental viscosity data for these mixtures requires the development of a new database, which is vital for understanding the behavior of mixtures in more complex systems, such as asphaltenes and fuels. The mixtures proposed in this work have been measured over a temperature range of (293.
View Article and Find Full Text PDFWater-in-salt electrolytes have attracted considerable interest in the past decade for advanced lithium-ion batteries, possessing important advantages over the non-aqueous electrolytes currently in use. A battery with a LiTFSI-water electrolyte was demonstrated in which an operating window of 3 V is made possible by a solid-electrolyte interface. Viscosity is an important property for such electrolytes, because high viscosity is normally associated with low ionic conductivity.
View Article and Find Full Text PDFThe probability of a two-photon absorption (TPA) process is quantified by means of the TPA cross-section. In this work the TPA cross-section for the 6S → 8S transition in cesium (Cs) atoms is obtained from a theoretical and experimental approach. It is calculated using second order perturbation theory including hyperfine structure and Doppler broadening for a thermal atomic vapor.
View Article and Find Full Text PDFA new class of electrolytes have been reported, hybridizing aqueous with non-aqueous solvents, which combines non-flammability and non-toxicity characteristics of aqueous electrolytes with the superior electrochemical stability of non-aqueous systems. Here, we report measurements of the structure of an electrolyte composed of an equal-mass mixture of 21 m LiTFSI-water and 9 m LiTFSI-dimethyl carbonate using high-energy x-ray diffraction and polarized neutron diffraction with isotope substitution. Neutron structure factors from partially and fully deuterated samples exhibit peaks at low scattering vector Q that we ascribe to long-range correlations involving both solvent molecules and TFSI anions.
View Article and Find Full Text PDFAmorphous solid dispersions (ASDs) are one of the promising strategies to improve the solubility and dissolution rate of poorly soluble compounds. In this study, Molecular Dynamics simulations were used to investigate the interactions between three selected stilbenoids with important biological activity (resveratrol, pinostilbene and pterostilbene) and poly(vinylpyrrolidone). The analysis of the pair distribution functions and hydrogen bond distributions reveals a significant weakening of the hydrogen bond network of the stilbenoids in ASDs compared to the pure (no polymer) amorphous systems.
View Article and Find Full Text PDFThere is an urgent need to understand severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-host interactions involved in virus spread and pathogenesis, which might contribute to the identification of new therapeutic targets. In this study, we investigated the presence of SARS-CoV-2 in postmortem lung, kidney, and liver samples of patients who died with coronavirus disease (COVID-19) and its relationship with host factors involved in virus spread and pathogenesis, using microscopy-based methods. The cases analyzed showed advanced stages of diffuse acute alveolar damage and fibrosis.
View Article and Find Full Text PDFIntroduction: The anti-CD20 antibody rituximab (RTX) has substantially improved outcomes of patients with B-cell lymphomas, although more efficient therapies are needed for refractory or relapsing lymphomas. An approach to increase the clinical effectiveness of anti-tumor therapy is the use of antibody-cytokine fusion proteins (immunocytokines (ICKs)) to deliver at the tumor site the antibody effector functions and cytokines that trigger anti-tumor activities. In particular, IL-2-based ICKs have shown significant results in preclinical studies but not in clinical trials due to the toxicity profile associated to high doses IL-2 and the undesired expansion of Tregs.
View Article and Find Full Text PDFBackground: Current evidence on obstetric patients requiring advanced ventilatory support and impact of delivery on ventilatory parameters is retrospective, scarce, and controversial.
Research Question: What are the ventilatory parameters for obstetric patients with COVID-19 and how does delivery impact them? What are the risk factors for invasive mechanical ventilation (IMV) and for maternal, fetal, and neonatal mortality?
Study Design And Methods: Prospective, multicenter, cohort study including pregnant and postpartum patients with COVID-19 requiring advanced ventilatory support in the ICU.
Results: Ninety-one patients were admitted to 21 ICUs at 29.
We report a systematic diffraction study of two "water-in-salt" electrolytes and a "water-in-bisalt" electrolyte combining high-energy X-ray diffraction (HEXRD) with polarized and unpolarized neutron diffraction (ND) on both HO and DO solutions. The measurements provide three independent combinations of correlations between the different pairs of atom types that reveal the short- and intermediate-range order in considerable detail. The ND interference functions show pronounced peaks around a scattering vector ∼ 0.
View Article and Find Full Text PDFSpan J Psychiatry Ment Health
May 2024
Introduction: Mental health (MH) care has important challenges, especially in the field of humanization. Our objectives were to identify the humanization measures in MH plans of the Spanish autonomous communities (AC) and the priorities to be developed in this area.
Material And Methods: A large and multidisciplinary group of people involved in MH care participated in a consensus, according to a modified Delphi method, based on «design thinking», in three phases: (1) identification of humanization measures in MH plans of AC; (2) analysis of the implementation of these measures; and (3) identification of humanization priorities in MH.
Adding salt to water at ambient pressure affects its thermodynamic properties. At low salt concentration, anomalies such as the density maximum are shifted to lower temperature, while at large enough salt concentration, they cannot be observed any more. Here, we investigate the effect of salt on an anomaly recently observed in pure water at negative pressure: the existence of a sound velocity minimum along isochores.
View Article and Find Full Text PDFMany important processes affecting the earth's climate are determined by the physical properties of seawater. In addition, desalination of seawater is a significant source of drinking water for the human population living in coastal areas. Since the physical properties of seawater governing these processes depend on the molecular interactions among its components, a deeper knowledge of seawater at the molecular level would contribute to a better understanding of these phenomena.
View Article and Find Full Text PDFJ Phys Chem Lett
September 2020
"Water-in-salt" (WIS) and "water-in-bisalt" (WIBS) electrolytes have recently been developed for Li-ion batteries, combining the safety and environmental friendliness of aqueous electrolytes with a larger operating window made possible by a solid-electrolyte interphase. We report quasielastic neutron scattering (QENS) measurements on solutions of a WIS electrolyte at two concentrations, 13.9 and 21 (molal) lithium bis(trifluoromethane)sulfonimide LiTFSI in HO/DO and a WIBS electrolyte at (21 LiTFSI + 7 lithium triflate (LiOTf)) in HO/DO.
View Article and Find Full Text PDFLipid asymmetry is a crucial property of biological membranes and significantly influences their physical and mechanical properties. It is responsible for maintaining different chemical environments on the external and internal surfaces of cells and organelles and plays a vital role in many biological processes such as cell signalling and budding. In this work we show, using non-equilibrium molecular dynamics (NEMD) simulations, that thermal fields can induce lipid asymmetry in biological membranes.
View Article and Find Full Text PDFThe asymmetric distribution of lipids in the cell membrane is maintained by protein transporters, and in the absence of proteins, by spontaneous flip-flop of lipids that involve the formation of transient pores in the membrane. The composition of the cell membranes influences the metabolism of the cell by modulating the function of transmembrane proteins, and flip-flop processes are therefore of key importance. Membranes are in direct contact with aqueous solutions, containing ions of different compositions that interact with the lipid head groups or cross the cell membrane through transmembrane channels.
View Article and Find Full Text PDFACS Appl Mater Interfaces
November 2019
While the focus of research related to the design of robust, high-performance Li-ion batteries relates primarily to the synthesis of active particles, the binder plays a crucial role in stability and ensures electrode integrity during volume changes that occur with cycling. Conventional polymeric binders such as poly(vinylidene difluoride) generally do not interact with active particle surfaces and fail to accommodate large changes in particle spacing during cycling. Thus, attention is now turning toward the exploration of interfacial interactions between composite electrode constituents as a key element in ensuring electrode stability.
View Article and Find Full Text PDFACS Appl Mater Interfaces
October 2019
Rational design and construction of effective silicon (Si) electrode structures to relieve large volumetric changes that occur during the charge/discharge process remain significant challenges for the development of robust lithium-ion batteries (LIBs). Herein, we propose an electrically conductive poly[3-(potassium-4-butanoate)thiophene] (PPBT) capping layer on the Si surface (Si@PPBT) to serve as the active material and be used in conjunction with a common polymer binder as an approach to tackle issues emanating from volumetric changes. The PPBT protective shell layer provides the system with tolerance toward variations in active material volume during cycling, improves the dispersion of Si nanoparticles in the binder, enhances the electrolyte uptake rate, and provides a strong adhesion force between the Si/carbon additives/current collector, thereby helping to maintain electrode integrity during the charge/discharge process.
View Article and Find Full Text PDFPhys Chem Chem Phys
November 2018
Tetrabutylammonium (TBA) and tetraphenylborate (TPB) ions dissolved in dichloroethane (DCE) are widely used in electrochemistry of liquid-liquid interfaces. Unlike alkali halide solutions in water, TBA-TPB-DCE solutions feature large organic ions and a solvent with a dielectric constant almost one order of magnitude lower than that of water. This is expected to dramatically amplify the impact of ionic correlations in the properties of the solution.
View Article and Find Full Text PDFThermal transport in ice features an unusual response. In addition to its intrinsic scientific interest, an understanding of the mechanisms determining the thermal conductivity of ice might be relevant in climate modelling and planetary science. Accurate microscopic models can provide important molecular insight into these mechanisms.
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