The function of biomolecular systems, including biological macromolecules, often crucially depends on their dynamics. Nuclear magnetic resonance (NMR) is one of the most informative methods used to study biomolecules and their internal mobility, with atomic resolution, in near-physiological conditions. NMR relaxation profiles, obtained from the field dependence of the nuclear relaxation rates, in particular, offer the possibility to probe dynamic processes over a wide range of time scales.
View Article and Find Full Text PDFH and F spin-lattice relaxation experiments have been performed for a series of ionic liquids: [HMIM][TFSI], [OMIM][TFSI], and [DMIM][TFSI] including the same anion and cations with progressively longer alkyl chains. The experiments were performed in a wide frequency range from 10 kHz to 10 MHz (referring to the H resonance frequency) versus temperature. This extensive data set has been analyzed in terms of a theoretical model including all relevant homonuclear (H-H and F-F) and heteronuclear (H-F) relaxation pathways and linking the relaxation features to the relative translational diffusion between the ion pairs (cation-cation, cation-anion, and anion-anion).
View Article and Find Full Text PDF1H spin-lattice relaxation experiments have been performed for ionic liquid-polymer gel membranes, including 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF4]) and poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP) with different proportions. The experiments have been performed in a broad range of resonance frequencies (from about 5 Hz to 40 MHz) vs temperature and complemented with analogous studies for [BMIM][BF4] in bulk as a reference. A model of the relaxation processes in the membranes has been proposed.
View Article and Find Full Text PDFThis paper presents a comprehensive overview of the spin relaxation theory needed for exploring nuclear magnetic resonance (NMR) relaxometry to study the dynamical properties of ionic liquids. The term NMR relaxometry refers to relaxation experiments performed over a wide range of magnetic fields (resonance frequencies). In this way, dynamical processes occurring on timescales from milliseconds to nanoseconds can be studied, including translational and rotational dynamics of both types of ions (cations and anions).
View Article and Find Full Text PDFThis work presents an approach to exploiting Nuclear Magnetic Resonance (NMR) relaxometry data (H spin-lattice relaxation rates covering the frequency range from below 1 kHz to 10 MHz) for the purpose of differentiating between pathological and reference tissues. Characteristic quantities (markers) that can be obtained in a straightforward manner, not resorting to an advanced analysis of H spin-lattice relaxation data, have been identified and compared for pathological and reference colon tissues. Moreover, the relaxation data have been parametrised in terms of Lorentzian spectral densities and the possibility of using the obtained dipolar relaxation constants and correlation times as biomarkers to assess the state of tissues has been discussed.
View Article and Find Full Text PDFH spin-lattice relaxation experiments have been performed for gels based on fish collagen in order to analyze water dynamics. The covered frequency range ranges from 10 kHz to 10 MHz; in some cases, the temperature has varied as well. The relaxation data have been reproduced in terms of two models of water motion-a model including two relaxation contributions associated with the diffusion of water molecules on the macromolecular surfaces and a second model being just a phenomenological power law.
View Article and Find Full Text PDFH fast field-cycling and time-domain nuclear magnetic resonance relaxometry studies have been performed for 15 samples of sugar of different kinds and origins (brown, white, cane, beet sugar). The extensive data set, including results for crystal sugar and sugar/water mixtures, has been thoroughly analyzed, with a focus on identifying relaxation contributions associated with the solid and liquid fractions of the systems and non-exponentiality of the relaxation processes. It has been observed that H spin-lattice relaxation rates for crystal sugar (solid) vary between 0.
View Article and Find Full Text PDFThe aim of the study was to enquire to which extend H spin-lattice nuclear magnetic resonance (NMR) relaxometry data collected over a broad range of resonance frequencies (from 10 kHz to 10 MHz) have the potential to be used for assessing quality and authenticity of different categories of cheese. The following cheeses were selected mozzarella, processed cheese, pizza cheese, pizza cheese with modified fat phase), low-fat cheese, and long ripened cheese. The cheeses from 3 different production plants and various cheese production batches were used in the study.
View Article and Find Full Text PDF1H spin-lattice Nuclear Magnetic Resonance relaxometry experiments have been performed for collagen and collagen-based artificial tissues in the frequency range of 10 kHz-20 MHz. The studies were performed for non-hydrated and hydrated materials. The relaxation data have been interpreted as including relaxation contributions originating from 1H-1H and 1H-14N dipole-dipole interactions, the latter leading to Quadrupole Relaxation Enhancement effects.
View Article and Find Full Text PDF1H spin-lattice relaxation studies have been performed for binary systems, including glycerol as the first component and alanine, glycine, and aspartic acid (with different levels of deuteration) as the second one. The relaxation studies have been performed in the frequency range from 10 kHz to 10 MHz vs temperature. A theoretical framework, including all relevant 1H-1H and 1H-2H relaxation pathways, has been formulated.
View Article and Find Full Text PDFThe aim of this study was to investigate whether Trail Making Test (TMT) performance is associated with the severity of psychopathological symptoms related to psychosis among young adults with elevated level of psychotic-like experiences (PLEs), and whether this relationship is mediated by cognitive biases and socio-occupational functioning. A total of 187 subjects from a larger population of 6722 young adults participated in this 1-year follow-up study. The inclusion criteria were an elevated level of PLEs (the highest score of the Prodromal Questionnaire) and a lack of schizophrenia diagnosis.
View Article and Find Full Text PDFH spin-lattice relaxation experiments have been performed for water and glycerol/water solutions of HN-FeO superparamagnetic nanoparticles (NPs) of about 7 nm diameter. The experiments encompass a broad frequency range covering 3 orders of magnitude, from 10 kHz to 10 MHz (referring to H resonance frequency), and have been performed in the temperature range from 298 to 313 K, varying the concentration of the superparamagnetic species. This extensive dataset has been used for twofold purposes.
View Article and Find Full Text PDFH spin-lattice nuclear magnetic resonance (NMR) relaxation experiments have been performed for water dispersions of functionalized silica nanoparticles of diameters of 25 and 45 nm. The experiments have been performed in a broad frequency range spanning 3 orders of magnitude, from 10 kHz to 10 MHz, versus temperature, from 313 to 263 K. On the basis of the data, two-dimensional translation diffusion (diffusion close to the nanoparticle surface within a layer of the order of a few diameters of water molecules) has been revealed.
View Article and Find Full Text PDFWater dynamics in mesoporous dextran hydrogel micro/nanoparticles was investigated by means of nuclear magnetic resonance (NMR) techniques. High-resolution H NMR spectra and pulsed field gradient (PFG) NMR diffusometry measurements obtained on swollen state dextran micro/nanogel revealed the existence of different fractions of water molecules based on their interaction with the gel matrix. In addition to the translational diffusion of bulk water, two more diffusion processes characterized with self-diffusion coefficients 1 and 2 orders of magnitude smaller than that of bulk water were identified.
View Article and Find Full Text PDFIonic liquids (ILs), revealing a tendency to form self-assembled nanostructures, have emerged as promising materials in various applications, especially in energy storage and conversion. Despite multiple reports discussing the effect of structural factors and external thermodynamic variables on ion organization in a liquid state, little is known about the charge-transport mechanism through the self-assembled nanostructures and how it changes at elevated pressure. To address these issues, we chose three amphiphilic ionic liquids containing the same tetra(alkyl)phosphonium cation and anions differing in size and shape, i.
View Article and Find Full Text PDFH spin-lattice Nuclear Magnetic Resonance relaxation studies have been performed for different kinds of Haribo jelly and Vidal jelly in a very broad frequency range from about 10 kHz to 10 MHz to obtain insight into the dynamic and structural properties of jelly candies on the molecular level. This extensive data set has been thoroughly analyzed revealing three dynamic processes, referred to as slow, intermediate and fast dynamics occurring on the timescale of 10 s, 10 s and 10 s, respectively. The parameters have been compared for different kinds of jelly for the purpose of revealing their characteristic dynamic and structural properties as well as to enquire into how increasing temperature affects these properties.
View Article and Find Full Text PDFActa Otorrinolaringol Esp (Engl Ed)
March 2023
Introduction And Objectives: To compare clinical and psychoacoustic tinnitus characteristics in patients with the comorbidity of hyperacusis, hyperacusis and vertigo, and with Ménière's disease (MD).
Materials And Methods: Three hundred and twenty-nine tinnitus patients underwent audiological and otoneurological evaluation. Records of 94 individuals younger than 65 years, 40 women and 54 men (mean age 41.
H spin-lattice relaxation experiments have been performed for water-Bovine Serum Albumin (BSA) mixtures, including 20%wt and 40%wt of BSA. The experiments have been carried out in a frequency range encompassing three orders of magnitude, from 10 kHz to 10 MHz, versus temperature. The relaxation data have been thoroughly analyzed in terms of several relaxation models with the purpose of revealing the mechanisms of water motion.
View Article and Find Full Text PDFObjectives: Virtual reality (VR) is growing in popularity in treating various psychiatric disorders, including psychotic ones. However, no studies have been published on mindfulness interventions aided by virtual reality in psychotic patients to date.
Methods: 25 patients with schizophrenia or schizoaffective disorder were assessed at three time points with 4-week intervals using the six-item Positive and Negative Syndrome Scale (PANSS-6), Quick Inventory of Depressive Symptomatology (QIDS), Beck Depression Inventory (BDI), Beck Anxiety Inventory (BAI), State-Trait Anxiety Inventory (STAI), Perceived Stress Scale (PSS-10), and the Addenbrooke's Cognitive Examination III (ACE-III).
Background: Chronic obstructive pulmonary disease (COPD) is characterized by irreversible lung tissue damage. Novel regenerative strategies are urgently awaited. Cultured mesenchymal stem/stromal cells (MSCs) have shown promising results in experimental models of COPD, but differences between sources may impact on their potential use in therapeutic strategies in patients.
View Article and Find Full Text PDFThe combination of superparamagnetic iron oxide nanoparticles (SPIONs) and lipid matrices enables the integration of imaging, drug delivery, and therapy functionalities into smart theranostic nanocomposites. SPION confinement creates new interactions primarily among the embedded SPIONs and then between the nanocomposites and the surroundings. Understanding the parameters that rule these interactions in real interacting (nano)systems still represents a challenge, making it difficult to predict or even explain the final (magnetic) behavior of such systems.
View Article and Find Full Text PDFObjectives: Virtual Reality (VR) has been widely used in psychiatry, including psychotic disorders. The main advantage of VR is its high ecological validity and controllability of the virtual environment. Our main goal was to test whether, similarly to computer-generated VR, 360-degree videos are able to elicit a state of social paranoia in prone individuals.
View Article and Find Full Text PDFF Nuclear Magnetic Resonance spin-lattice relaxation experiments have been performed for a series of ionic liquids including the same anion, bis(trifluoromethanesulfonyl)imide, and cations with alkyl chains of different lengths: triethylhexylammonium, triethyloctylammonium decyltriethylammonium, dodecyltriethylammonium, decyltriethylammonium, and hexadecyltriethylammonium. The experiments have been carried out in a frequency range of 10 kHz to 10 MHz versus temperature. A thorough analysis of the relaxation data has led to the determination of the cation-anion as a relative translation diffusion coefficient.
View Article and Find Full Text PDFStarch-based confectionery products were prepared using different types of sugar. In addition to using different sugar, starch was replaced with soy protein isolate (SPI) in some of the products. H NMR spin-lattice relaxation experiments were performed for the collection of products in a broad frequency range from 4 KHz to 30 MHz to get insight into the influence of different sugar types and SPI on the dynamics of water in composite gel systems.
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