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This article presents the application of continuous Floquet theory in solid-state nuclear magnetic resonance (NMR). Continuous Floquet theory extends the traditional Floquet theory to non-continuous Hamiltonians, enabling the description of observable effects not fully captured by the traditional Floquet theory due to its requirement for a periodic Hamiltonian. We present closed-form expressions for computing first- and second-order effective Hamiltonians, streamlining integration with the traditional Floquet theory and facilitating application in NMR experiments featuring multiple modulation frequencies. Subsequently, we show examples of the practical application of continuous Floquet theory by investigating several solid-state NMR experiments. These examples illustrate the importance of the duration of the pulse scheme regarding the width of the resonance conditions and the near-resonance behavior. [ABSTRACT FROM AUTHOR]

Traditionally, the stuffing model has been used to describe stress generation in chemically strengthened glass. Nevertheless, the associated unrealistic conditions, including an imaginary volume expansion and its suppression in an adiabatic closed system, inhibit a thorough understanding of the process. In this study, we propose a thermodynamic model in an isothermal open system to enable ion exchange without an imaginary volume expansion. We derive a fundamental equation and verify it using atomistic images obtained by Raman spectroscopy and nuclear magnetic resonance. This study paves the way for further atomistic design and development of strengthened glasses. [ABSTRACT FROM AUTHOR]

This study explored the interplay between the ligand–surface chemistry of colloidal CsPbBr3 nanowires (NWs) and their optical properties. The ligand equilibrium was probed using nuclear magnetic resonance spectroscopy, and by perturbing the equilibrium via dilution, the gradual removal of ligands from the CsPbBr3 surface was observed. This removal was correlated with an increase in the surface defect density, as suggested by a broadening of the photoluminescence (PL) spectrum, a decrease in the PL quantum yield (PLQY), and quenching of the PL decay. These results highlight similar surface binding between the traditional CsPbBr3 quantum dots and our NWs, thereby expanding the scope of well-established ligand chemistry to a relatively unexplored nanocrystal morphology. By controlling the dilution factor, it was revealed that CsPbBr3 NWs achieve a PLQY of 72% ± 2% and a relatively long average PL lifetime of 400 ± 10 ns, without relying on additional surface passivation techniques, such as ligand exchange. [ABSTRACT FROM AUTHOR]

A new algorithm has been developed to simulate two-dimensional (2D) spectra with correlated anisotropic frequencies faster and more accurately than previous methods. The technique uses finite-element numerical integration on the sphere and an interpolation scheme based on the Alderman–Solum–Grant algorithm. This method is particularly useful for numerical calculations of joint probability distribution functions involving quantities with a parametric orientation dependence. The technique's efficiency also allows for practical least-squares fitting of experimental 2D solid-state nuclear magnetic resonance (NMR) datasets. The simulation method is illustrated for select 2D NMR methods, and a least-squares analysis is demonstrated in the extraction of paramagnetic shift and quadrupolar coupling tensors and their relative orientation from the experimental shifting-d echo 2H NMR spectrum of a NiCl2 · 2D2O salt. [ABSTRACT FROM AUTHOR]

A series of biobased aliphatic-aromatic copolyesters, poly(pentylene dodecanoate-co-furandicarboxylates) (PPeDFs) were synthesized via an esterification and polycondensation melt process. The copolyesters were characterized using gel permeation chromatography, Fourier transform infrared spectroscopy, [sup.1]H NMR spectroscopy, differential scanning calorimetry, thermogravimetric analysis, wide angle x-ray scattering, and tensile testing. The thermal transition behavior was strongly dependent on composition, with the melting and glass transition temperatures reaching a minimum at approximately equimolar ratio of D to F. All copolyesters were stable below 300[degrees] C with their [R.sub.600] (the weight of material remaining at 600[degrees]C) values increasing with F fraction. PPeD to PPeDF30 (e.g., mole ratio DIF = 7:3) show sharp PPeD crystalline reflections only while broad PPeF reflections are shown in PPeF and PPeDF90. PPeDF40 to PPeDF80 showed both crystal structures. The fractional crystallinity for the PPeD was much higher than PPeF and the fractional crystallinity of the copolymers showed a minimum at D/F ratios closer to the latter. The stress at break and modulus both exhibited maxima at D/F ratios that were either high or low, but somewhat surprisingly a strong maximum in percent elongation at break of over 600% occurs at PPeDF40. For this composition, a typical plastic behavior curve was found including a yield point, high elongation at break, and strain hardening. Highlights * Poly(pentylene dodecanoate-co-furandicarboxylates) (PPeDFs) are synthesized * Mechanical properties, a function of D:F ratio. High elongation at 40 mol% F. * Two melting temperatures/crystal structures, one PPeD, the other PPeF * Glass transition temperature minimum at intermediate D:F ratios KEYWORDS dodecanedioic diacid, furandicarboxylic acid, pentanediol, polyesters, 1 | INTRODUCTION Furandicarboxylic acid (FDCA) based polyesters, because of their biobased and biodegradable characteristics, have gained significant attention in recent years due to their potential to replace traditional petrochemical-based [...]

The effect of replacing magnesia by alumina on the pressure-dependent structure of amorphous enstatite was investigated by applying in situ high-pressure neutron diffraction with magnesium isotope substitution to glassy (MgO)0.375(Al2O3)0.125(SiO2)0.5. The replacement leads to a factor of 2.4 increase in the rate-of-change of the Mg–O coordination number with pressure, which increases from 4.76(4) at ambient pressure to 6.51(4) at 8.2 GPa, and accompanies a larger probability of magnesium finding bridging oxygen atoms as nearest-neighbors. The Al–O coordination number increases from 4.17(7) to 5.24(8) over the same pressure interval at a rate that increases when the pressure is above ∼3.5 GPa. On recovering the glass to ambient conditions, the Mg–O and Al–O coordination numbers reduce to 5.32(4) and 4.42(6), respectively. The Al–O value is in accordance with the results from solid-state 27Al nuclear magnetic resonance spectroscopy, which show the presence of six-coordinated aluminum species that are absent in the uncompressed material. These findings explain the appearance of distinct pressure-dependent structural transformation regimes in the preparation of permanently densified magnesium aluminosilicate glasses. They also indicate an anomalous minimum in the pressure dependence of the bulk modulus with an onset that suggests a pressure-dependent threshold for transitioning between scratch-resistant and crack-resistant material properties. [ABSTRACT FROM AUTHOR]

Traditional theories of the nuclear magnetic resonance (NMR) autocorrelation function for intra-molecular dipole pairs assume a single-exponential decay, yet the calculated autocorrelation of realistic systems displays a rich, multi-exponential behavior, resulting in anomalous NMR relaxation dispersion (i.e., frequency dependence). We develop an approach to model and interpret the multi-exponential intra-molecular autocorrelation using simple, physical models within a rigorous statistical mechanical development that encompasses both rotational diffusion and translational diffusion in the same framework. We recast the problem of evaluating the autocorrelation in terms of averaging over a diffusion propagator whose evolution is described by a Fokker–Planck equation. The time-independent part admits an eigenfunction expansion, allowing us to write the propagator as a sum over modes. Each mode has a spatial part that depends on the specified eigenfunction and a temporal part that depends on the corresponding eigenvalue (i.e., correlation time) with a simple, exponential decay. The spatial part is a probability distribution of the dipole pair, analogous to the stationary states of a quantum harmonic oscillator. Drawing inspiration from the idea of inherent structures in liquids, we interpret each of the spatial contributions as a specific molecular mode. These modes can be used to model and predict the NMR dipole–dipole relaxation dispersion of fluids by incorporating phenomena on the molecular level. We validate our statistical mechanical description of the distribution in molecular modes with molecular dynamics simulations interpreted without any relaxation models or adjustable parameters: the most important poles in the Padé–Laplace transform of the simulated autocorrelation agree with the eigenvalues predicted by the theory. [ABSTRACT FROM AUTHOR]

Despite the importance of rhodium complexes in catalysis, and the favorable 100% natural abundance of the spin-1/2 103Rh nucleus, there are few reports of 103Rh nuclear magnetic resonance (NMR) parameters in the literature. In part, this is the consequence of the very low gyromagnetic ratio of 103Rh and its dismal NMR sensitivity. In a previous paper [Harbor-Collins et al., J. Chem. Phys. 159, 104 307 (2023)], we demonstrated an NMR methodology for 1H-enhanced 103Rh NMR and demonstrated an application to the 103Rh NMR of the dirhodium formate paddlewheel complex. In this paper, we employ selective 18O labeling to break the magnetic equivalence of the 103Rh spin pair of dirhodium formate. This allows the estimation of the 103Rh–103Rh spin–spin coupling and provides access to the 103Rh singlet state. We present the first measurement of a 18O-induced 103Rh secondary isotope shift as well as the first instance of singlet order generated in a 103Rh spin pair. The field-dependence of 103Rh singlet relaxation is measured by field-cycling NMR experiments. [ABSTRACT FROM AUTHOR]

Nuclear spin hyperpolarization derived from parahydrogen is a technique for enhancing nuclear magnetic resonance (NMR) sensitivity. The key to hyperpolarization experiments is to achieve rapid transfer and detection to minimize relaxation losses, while also avoiding bubbles or turbulence to guarantee high spectral resolution. In this article, we describe an experimental approach for the interleaved joint modulation of parahydrogen-induced polarization and NMR. We provide schematic diagrams of parahydrogen-based polarizer with in situ high-pressure detection capability and low-field polarization transfer. This approach can help to control the experimental process and acquire experimental information, one example of which is the attainment of the highest hyperpolarization signal intensity at 3.6 s after closing the valve. The polarizer demonstrates in situ detection capability, allowing sample to be restabilized within 0.3 ± 0.1 s and high-resolution NMR sampling under a pressure of 3 bars. Moreover, it can transfer polarized samples from the polarization transfer field to the detection region of NMR within 1 ± 0.3 s for completing signal amplification by reversible exchange experiments. [ABSTRACT FROM AUTHOR]

We present a gauge-origin invariant exact two-component (X2C) approach within a modern density functional framework, supporting meta-generalized gradient approximations such as TPSS and range-separated hybrid functionals such as CAM-B3LYP. The complete exchange-correlation kernel is applied, including the direct contribution of the field-dependent basis functions and the reorthonormalization contribution from the perturbed overlap matrix. Additionally, the finite nucleus model is available for the electron-nucleus potential and the vector potential throughout. Efficiency is ensured by the diagonal local approximation to the unitary decoupling transformation in X2C as well as the (multipole-accelerated) resolution of the identity approximation for the Coulomb term (MARI-J, RI-J) and the seminumerical exchange approximation. Errors introduced by these approximations are assessed and found to be clearly negligible. The applicability of our implementation to large-scale calculations is demonstrated for a tin pincer-type system as well as low-valent tin and lead complexes. Here, the calculation of the Sn nuclear magnetic resonance shifts for the pincer-type ligand with about 2400 basis functions requires less than 1 h for hybrid density functionals. Further, the impact of spin–orbit coupling on the nucleus-independent chemical shifts and the corresponding ring currents of all-metal aromatic systems is studied. [ABSTRACT FROM AUTHOR]

We report measurements of the Meissner screening profile in a Nb (300 nm)/ Al 2 O 3 thin film using 8 Li β -detected nuclear magnetic resonance (β -NMR). The NMR probe 8 Li was ion-implanted into the Nb film at energies ≤ 20 keV, corresponding to mean stopping depths comparable to Nb 's magnetic penetration depth λ. 8 Li 's strong dipole–dipole coupling with the host 93 Nb nuclei provided a "cross-relaxation" channel that dominated in low magnetic fields, which conferred indirect sensitivity to the local magnetic field via the spin-lattice relaxation (SLR) rate 1 / T 1. From a fit of the 1 / T 1 data to a model accounting for its dependence on temperature, magnetic field, and 8 Li + implantation energy, we obtained a magnetic penetration depth λ 0 = 51.5(22) nm, consistent with a relatively short carrier mean-free-path ℓ = 18.7(29) nm typical of similarly prepared Nb films. The results presented here constitute an important step toward using 8 Li β -NMR to characterize bulk Nb samples with engineered surfaces, which are often used in the fabrication of particle accelerators. [ABSTRACT FROM AUTHOR]

The theranostic pair mercury-197m and mercury-197g (197m/gHg, t1/2 = 23.8 h/64.14 h), through their γ rays and Meitner–Auger electron emissions, have potential use as constituents in radiopharmaceuticals to treat small metastatic tumours. However, the use of this pair of nuclear isomers in radiopharmaceuticals requires the development of suitable [197m/gHg]Hg2+ chelators as currently there is a lack of established ligands for radiometals in the field. Herein, this work studies the natHg/197m/gHg coordination of three thiacrown 18-membered N2S4 macrocycles with pendant arms of varying chemical "softness". Following the synthesis and characterization of the N2S4 ligand series (6,6′-((1,4,10,13-tetrathia-7,16-diazacyclooctadecane-7,16-diyl)bis(methylene))dipicolinic acid (N2S4-Pa), 7,16-bis(pyridin-2-ylmethyl)-1,4,10,13-tetrathia-7,16-diazacyclooctadecane (N2S4-Py) and 7,16-bis(2-(methylthio)ethyl)-1,4,10,13-tetrathia-7,16-diazacyclooctadecane (N2S4-Thio)), Hg2+ complexes were studied through mass spectrometry, nuclear magnetic resonance (NMR) spectroscopy, and density functional theory (DFT) calculations, revealing successful complexation of all ligands with the Hg2+ ion. Radiolabeling studies demonstrated the effect of the pendant arm on [197m/gHg]Hg2+ coordination, as N2S4-Thio and N2S4-Py had the highest radiochemical yield, similar to that of previously reported N-benzyl-2-(1,4,7,10-tetrathia-13-azacyclopentadecan-13-yl)acetamide (NS4-BA), while N2S4-Pa had the lowest. The complex integrity of [197m/gHg][Hg(N2S4-Py)]2+ and [197m/gHg][Hg(N2S4-Thio)]2+ in both human serum and glutathione was notably lower compared to the [197m/gHg][Hg(NS4-BA)]2+ complex. However, the [197m/gHg][Hg(N2S4-Py)]2+ and [197m/gHg][Hg(N2S4-Thio)]2+ complexes remained above 70% intact over 82 h when competed against biologically relevant metals (ZnCl2, FeCl3, CuCl2, MgCl2 and CoCl2), suggesting the selectivity of the ligands for Hg2+. This study illustrates the importance of the macrocyclic backbone size and electron-donor groups of the donor pendant arms in the design of chelators for 197m/gHg-radiopharmaceuticals, as both affect the radiolabeling properties and complex inertness. [ABSTRACT FROM AUTHOR]

Alcoholysis of Cp′3Ln (Ln = La, Ce; Cp′ = C5H4SiMe3) generate high-yielding (72–97%) bimetallic LnIII complexes of [Cp′2Ln(μ-OR)]2 [R = Et, iPr, or C6H4-4-tBu]. Single-crystal X-ray diffraction of these complexes reveal unexpected decreases in Ln⋯Ln distances, increasing Cpcent–Ln–Cpcent angles, and increasing intermolecular C⋯C contacts with bulkier bridging alkoxides, in line with structural control driven by significant dispersion forces. 1H NMR spectroscopy of [Cp′2Ce(μ-OEt)]2 and [Cp′2Ce(μ-OiPr)]2 revealed significantly upfield resonances assigned as methylene and methine moieties of −43.74 and −70.85 ppm, respectively. 2D 1H DOSY NMR experiments of [Cp′2Ce(μ-OiPr)]2 in C6D6 supported a dimeric structure in solution, including in the presence of a Lewis base (i.e., THF). Reduction of [Cp′2La(μ-OiPr)]2 using KC8 in the presence of 2.2.2-cryptand at −78 °C generated a purple solution and X-band EPR spectroscopy revealed an eight-line hyperfine pattern indicative of a LaII species. [ABSTRACT FROM AUTHOR]

The document is a contents list from the journal "Analyst" published by The Royal Society of Chemistry. It includes critical reviews, communications, and papers on various topics such as chemiluminescent probes, mass spectrometry, fingerprint detection, and fluorescence probes. The journal covers a wide range of research in the field of chemistry, showcasing diverse perspectives and innovative studies in the chemical sciences. [Extracted from the article]

Despite various developments in the application of quantitative nuclear magnetic resonance (qNMR) spectroscopy toward microplastics in recent years, this method still lacks suitable sample preparation and fractionation procedures. As this poses a crucial obstacle for its utilisation on environmental samples, which contain various mixtures of polymers along with other matrix substances, this research aims to address this missing link by presenting an easy-to-apply procedure based on common laboratory equipment. The process selectively separates microplastics from inorganic constituents while performing the necessary fractionation of different types of microplastics prior to qNMR analysis. It allows subsequent quantification of polystyrene (PS), polybutadiene rubber (BR), polymethylmethacrylate (PMMA), polyvinylchloride (PVC), polyethylene terephthalate (PET) and polyamide (PA) from a single sample, establishing recovery rates greater than 88% for all tested polymer types. Additionally, we extended our previous qNMR protocol to include two common polymer types: polymethylmethacrylate (PMMA) and polyacrylonitrile (PAN), achieving limits of detection down to 1.76 μg ml−1 and 12.53 μg ml−1 as well as limits of quantification down to 5.88 μg ml−1 and 41.78 μg ml−1, respectively. Thus, the qNMR method presented herein is now applicable to eight abundant polymer types, allowing the quantification of up to three different types simultaneously. [ABSTRACT FROM AUTHOR]

Background: Acute gamma-aminobutyric acid (GABAergic) effects of alcohol consumption are well-known, whereas prior research has yielded inconsistent findings regarding on adaptations of the GABAergic neurotransmitter system to chronic alcohol use. Previous studies indicate either elevated or reduced GABA levels in cortical regions such as the anterior cingulate cortex (ACC) in persons with alcohol use disorder (AUD). We tested the hypothesis that active alcohol consumption compared to abstinence contributes to GABA levels as observed in prior research on chronic alcohol use. Methods: We investigated GABA levels in the ACC of 31 healthy controls (low risk, LR), 38 high risk individuals providing an active drinking pattern (high risk, HR) and 27 recently detoxified alcohol-dependent (AD) subjects via proton magnetic resonance spectroscopy (1H-MRS). Results: GABA levels in the ACC were significantly lower in HR compared with AD, but did neither differ between LR and AD nor between LR and HR. Also, we observed a quadratic effect indicating a distribution of GABA levels in the ACC as follows: LR > HR < AD. GABA levels were not associated with abstinence duration in AD. Conclusions: This study suggests that the GABAergic neurotransmitter system is blunted in AUD. More precisely GABA levels in the ACC seem to be higher in recently detoxified AD patients than in individuals at high risk which might suggest that GABA levels may increase after abstinence. No correlation was found between GABA levels and abstinence duration. Longitudinal studies are required to investigate alterations in the GABAergic system throughout the development and maintenance of AUD. Clinical Trial Registration: No: NCT02094196. Registered 20 March 2014, https://clinicaltrials.gov/study/NCT02094196. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Layer‐by‐layer (LbL) solution processing is an efficient method to realize high performance organic solar cells (OSCs). One of the drawbacks of the LbL‐processed active layer is the large difference in the crystallinity of the donor and acceptor, which will lead to imbalance charge transfer and result in unfavorable charge recombination. Herein, we combined a novel volatile additive 3,5‐dichloro‐2,4,6‐ trifluorobenzotrifluoride (DTBF) with the LbL method to realize high‐efficiency OSCs. DTBF interacts with the non‐fullerene acceptor BTP‐4F by non‐covalent bonding, which enhances the crystallinity and compact stacking of BTP‐4F. DTBF doped OSC has balanced and efficient electron transport properties, longer carrier lifetime, higher exciton dissociation and charge collection efficiencies, lower energetic disorder than the control OSC without any additives. Benefiting from the optimization of charge dynamics and micro‐morphology by DTBF, the binary LbL‐processed OSC achieved synergistic improvements in open‐circuit voltage, short‐circuit current density and fill factor. As a result, a champion power conversion efficiency (PCE) of 19% is realized for DTBF‐optimized OSC, which is superior to the control OSC (17.55%). This work demonstrates a promising approach to modulate active layer morphology and fabricate high performance OSCs. [ABSTRACT FROM AUTHOR]

[Display omitted] Hypothesis: Limited research has been conducted on the influence of chelating agents on the self-assembly process in surfactant solutions. The traditional approach assumes the chelating agent only interferes as a salting-out ion, therefore promoting surfactant separation. However, the opposite behavior has been observed for iminodipropionate based surfactants, in which the presence of chelating agents of the aminopolycarboxylate type increases solubility of nonionic ethoxylated surfactants in mixed micellar systems. Specific interaction between chelating agents-surfactants can be an important parameter in the self-assembly processes. Experiments: Physicochemical properties of solutions containing amphoteric surfactant and tetrasodium glutamatediacetate have been investigated. Macroscopic properties, such as viscosity and cloud point, were evaluated in the presence of a non-water-soluble alkyl ethoxylated surfactant. Interactions between amphoteric surfactant and chelating agent were monitored by NMR spectroscopy, including 13C chemical shift and lineshape analysis as well as 1H diffusometry. Findings: The study reveals that there is an interaction between the head group of the surfactant and the chelating agent forming oligomeric surfactant analogues with larger hydrophilic moieties, which results in smaller, more spherical micelles. The combined interactions provide possibilities for tuning the aggregation behavior of systems containing surfactants and chelating agents, and with that, the macroscopic properties of the system. [ABSTRACT FROM AUTHOR]

19F nuclei serve as versatile sensors for detecting protein interactions and dynamics in biomolecular NMR spectroscopy. Although various methods have been developed to incorporate fluorine-containing aromatic residues into proteins using E. coli or cell-free expression techniques, similar approaches for protein production in mammalian cell lines remain limited. Here, we present a cost-effective synthetic route to obtain selectively deuterated, carbon-13 labeled fluorotryptophan and demonstrate its use in introducing 19F–13C spin pairs into carbonic anhydrase 2 and superoxide dismutase, following an expression protocol utilizing HEK cells. [ABSTRACT FROM AUTHOR]

To develop stable and efficient silver(I) catalysts and evaluate the role of sulfur and phosphorus donor ligands in the catalytic cycloaddition of selected organic azides and alkynes (AAC), a series of mononuclear Ag(I) and heteronuclear Ag(I)–Fe(II) complexes were synthesized. The synthesis utilized phosphine and sulfur donors from the dialkyldithiophosphate and borate families, specifically Na[S2H2B(mt)2]. These complexes are designated as [(dppf)AgSP(S)(OiPr)2] (1), [S2H2B(mt)2Ag(μ-dppf)AgS2H2B(mt)2] (2), [(dppf)Ag(μ-dppf)Ag(dppf)] (3), and [(dppe)AgS2H2B(mt)2] (5). The complexes 1–5 were characterized using a combination of 1H, 13C{1H}, and 31P{1H} NMR spectroscopy, as well as IR spectroscopy techniques. In two instances, single-crystal X-ray diffraction analysis was also employed. Complex 3 exhibited high catalytic activity and regioselectivity in the cycloaddition reaction conducted in water at 40 °C. [ABSTRACT FROM AUTHOR]

Solid-state nuclear magnetic resonance (NMR) spectroscopy serves as a powerful technique for probing local structures. However, the interpretation of NMR signals mainly based on empirical knowledge could lead to imprecise local structural determinations. To address this, density functional theory (DFT)-based theoretical NMR calculations, aided by experimental three-dimensional continuous rotation electronic diffraction (3D cRED) technique, were performed for ZnxY1−xBO3−0.5x borate oxide ion conductors. The calculations provided fine local structure identification for the experimental 11B NMR spectra of ZnxY1−xBO3−0.5x, providing rich information on multiple experimental 11B NMR signals towards the complex boron oxide anions associated with bridging oxygen vacancies and the coexistence of the monoclinic (C2/c), hexagonal (P63/m), and trigonal (R32) phases in ZnxY1−xBO3−0.5x. Owing to the advantages of solid-state NMR in identifying closely related phases compared to X-ray/neutron diffraction technique, along with the advanced 3D cRED technique that allows for rapid phase identification and structure determination, we provide a fine local structure identification and a more inclusive insight into the coexistence of multiple phases in borate with the same composition. More importantly, this work provides guidance for phase and property modulation. Phase modulation in ZnxY1−xBO3−0.5x was carried out with thermodynamic and kinetic modulation and eventually realized the tuning of the local structures and the resultant oxide ion conductivity of ZnxY1−xBO3−0.5x. This work provides a theoretical and experimental platform to access the flexible structural assignment of boron oxide anions and therefore offers new guidance and insights into the defect structures and the phase-property modulation of inorganic solid functional materials beyond borate oxide ion conductors. [ABSTRACT FROM AUTHOR]

ABSTRACT Canine lymphoma represents a biologically and metabolically heterogeneous group of neoplasms that arise from malignant transformation of lymphoid cells. An accurate diagnosis is crucial because of its impact on survival. Current diagnostic methods include clinical laboratory tests and imaging, most of which are invasive and lack sensitivity and specificity. Interestingly, recent work in cancer patients focuses on the search for biomarkers for diagnosis, investigation of treatment response mechanisms, treatment efficacy and prognosis and the discovery of tumour metabolic pathways using metabolomic analysis. In this study, we compare the metabolite profiles in serum from 37 dogs with multicentric lymphoma (22 B‐cell lymphomas/LB, 9 CD45+ T‐cell lymphomas/LTCD45+, 6 CD45‐ T‐cell lymphomas/LTCD45‐) and 25 healthy dogs using 1H nuclear magnetic resonance spectroscopy (NMR). 1H NMR‐based metabolite profiling analysis recognised lipids and 22 metabolites, with 16 of them altered, and was shown to be an effective approach for differentiating samples from dogs with lymphoma and healthy controls based on principal component analysis of the NMR data. We also investigated variations in the serum metabolome between immunophenotypes and the control group through pairwise comparisons of the healthy against the LB, LTCD45+ and LTCD45‐ groups, respectively which showed similar metabolomic profiles. In addition, there were significant differences in the levels of five individual metabolites based on the univariate statistical analysis. Our results showed alterations in energy, protein and lipid metabolism, suggesting glucose, lactate, N‐acetyl glycoproteins (NAGs), scyllo‐inositol and choline as possible new candidate biomarkers in canine multicentric lymphoma. [ABSTRACT FROM AUTHOR]

The carbene-stabilised beryllium Grignards [(CAAC)BeBrR] (R = CAACH 1a, Dur 1b; CAAC/H = 1-(2,6-diisopropylphenyl)-2,2,4,4-tetramethylpyrrolidin-2-yl/idene; Dur = 2,3,5,6-tetramethylphenyl) undergo salt metathesis with various pseudohalide salt precursors. Whereas with [NaNCS] the thiocyanato Grignards [(CAAC)Be(NCS)R] (R = CAACH 2a, Dur 2b) are obtained selectively, salt metatheses with [Na(OCP)(dioxane)2.3] and [K(OCN)] are fraught with side reactions, in particular scrambling of both neutral and anionic ligands, leading to complex product mixtures, from which the first examples of beryllium phosphaethynolate Grignards [(thf)2(CAACH)Be(OCP)] (3) and [(CAAC)Be(OCP)R] (R = CAACH 4a, Dur 4b), as well as the isocyanate-bridged hexamer [(CAAC)BrBe(1,3-μ-OCN)]6 (7) were determined as the main products. The complexity of possible side reactions is seen in complex 5, a byproduct of the salt metathesis of 1b with [Na(OCP)(dioxane)2.3], which hints at radical redox processes, OCP homocoupling, OCP coupling with CAAC, as well as OCP insertion into the Be–R bond. Finally, the unstable, tetrameric cyano-bridged beryllium Grignard [(thf)(CAACH)Be(1,2-μ-CN)] (8) was obtained by salt metathesis of 1a with [Na/KSeCN] alongside one equiv. CAAC＝Se. The new complexes were characterised by heteronuclear NMR and IR spectroscopy, as well X-ray crystallography. [ABSTRACT FROM AUTHOR]

Polyanion rotations are often linked to cation diffusion, but the study of multiple polyanion systems is scarce due to the complexities in experimentally determining their dynamic interactions. This work focuses on BH4‐based argyrodites, synthesized to achieve a high conductivity of 11 mS cm−1. Advanced tools, including high‐resolution X‐ray diffraction, neutron pair distribution function analysis, and mutinuclear magic‐angle‐spinning nuclear magnetic resonance (NMR) spectroscopy and relaxometry, along with theoretical calculations, are employed to unravel the dynamic intricacies among the dual polyanion lattice and active charge carriers. The findings reveal that the anion sublattice of Li5.07PS4.07(BH4)1.93 affords an even temporal distribution of Li among PS43− and BH4−, suggesting minimal trapping of the charge carriers. Moreover, the NMR relaxometry unveils rapid BH4− rotation on the order of ∼GHz, affecting the slower rotation of neighboring PS43− at ∼100 MHz. The PS43− rotation synchronizes with Li+ motion and drives superionic transport. Thus, the PS43− and BH4− polyanions act as two‐staged dual motors, facilitating rapid Li+ diffusion. [ABSTRACT FROM AUTHOR]

Objective Methods Results Interpretation The genetic causes of a significant number of patients with cerebellar ataxia remain unsolved. Variations in the ITM2B gene, typically linked to dominantly inherited dementia, can sometimes present with cerebellar ataxia as an early symptom. This study aims to investigate the role of ITM2B variations in a Taiwanese cohort with unsolved cerebellar ataxia.Genetic analysis of ITM2B was performed in 212 unrelated Taiwanese patients with unsolved cerebellar ataxia. Eight short tandem repeat markers flanking ITM2B were genotyped to analyze the associated haplotype. Affected carriers underwent comprehensive clinical evaluations.A heterozygous ITM2B variant, c.800G>T (p.(Ter267LeuextTer11)), was identified in three patients. Haplotype analysis demonstrated a shared haplotype linked to this variant in the three families, suggesting a founder effect. The three probands and additional three affected relatives presented with cerebellar ataxia and unsteady gait with an average onset age of 43.2 years. Most participants had no cognitive impairment at symptom onset but experienced memory decline, oculomotor disturbances, lower limb spasticity, and extensor plantar responses within 2–5 years. Magnetic resonance imaging and spectroscopy revealed progressive extension of white matter hyperintensity over periventricular and subcortical regions, subtle hippocampal atrophy, preserved cerebellar volumes, and decreased N‐acetylaspartate/creatine ratio over the vermis.ITM2B mutations accounted for 1.4% of cerebellar ataxia cases in the Taiwanese cohort, with patients carrying ITM2B c.800G>T descending from a common ancestor. This study underscores the importance of considering ITM2B variations as a potential cause of cerebellar ataxia, even in the absence of dementia at the initial presentation. [ABSTRACT FROM AUTHOR]

The microtubule‐associated protein tau forms disease‐specific filamentous aggregates in several different neurodegenerative diseases. In order to understand how tau undergoes misfolding into a specific filament type and to control this process for drug development purposes, it is crucial to study in vitro tau aggregation methods and investigate the structures of the obtained filaments at the atomic level. Here, we used the tau fragment dGAE, which aggregates spontaneously, to seed the formation of full‐length tau filaments. The structures of dGAE and full‐length tau filaments were investigated by magic‐angle spinning (MAS) solid‐state NMR, showing that dGAE allows propagation of a chronic traumatic encephalopathy (CTE)‐like fold to the full‐length tau. The obtained filaments efficiently seeded tau aggregation in HEK293T cells. This work demonstrates that in vitro preparation of disease‐specific types of full‐length tau filaments is feasible. [ABSTRACT FROM AUTHOR]

While organic matter (OM) interactions in the water column prevent iron (Fe) precipitation and sedimentation, Fe also acts as a precursor of aggregation and a vector of OM to sediments. This study aims to characterize Fe–OM interactions to understand the role of Fe in promoting aggregation and transport of OM. Samples of Fe and OM were collected from water, settling material, and sediment along a gradient starting from the inlet and continuing offshore within a boreal lake. Fe speciation was determined using X-ray absorption spectroscopy (XAS), and the chemical composition of OM was assessed using Diffuse reflectance infrared Fourier transform spectroscopy (DRIFT IR) and Nuclear magnetic resonance spectroscopy (NMR). The results show a decrease in Fe and OM concentrations in the water column with increasing distance from the inlet. Winter sampling revealed a shift in Fe speciation from dominance of organically complexed Fe to an increase in Fe(oxy)hydroxide, accompanied by a loss of aromatic and carboxylate function of OM. Summer sampling revealed no significant changes along the gradient, with Fe(oxy)hydroxide and carbohydrates dominating the water phase. Interestingly, settling particles and surface sediments were dominated by Fe(oxy)hydroxides and aliphatic OM. We propose that phototransformation may be an important process that influences the interaction between Fe and OM and, as a consequence, their fate along the spatial gradient. Our study suggests a photochemically induced loss of carboxylate groups, reflected by an increased carbohydrate-to-carboxylate ratio along the gradient, particularly in winter, and generally lower levels during summer. Loss of carboxylate function promotes the formation of Fe(oxy)hydroxides, which in turn, facilitates the aggregation and sinking of OM, particularly aliphatic components. These insights contribute to a broader understanding of carbon cycling and storage in lakes. Future studies should assess the significance of photochemical processes to OM burial and it how may change given trends in Fe and OM in northern regions. [ABSTRACT FROM AUTHOR]

Objectives GCA is an inflammatory disease following a chronic, relapsing course. The metabolic alterations related to the intense inflammatory process during the active phase and the rapid impact of steroid treatment remain unknown. This study aims to investigate the serum metabolome in active and inactive disease states. Methods A total of 110 serum samples from 50 patients (33 GCA and 17 PMR) at three time points—0 (V1: active disease), 1 and 6 months (V2 and V3: remission)—of treatment with glucocorticoids (GCs) were subjected to NMR-based metabolomic analysis. Multi- and univariate statistical analyses were utilized to unveil metabolome alterations following treatment. Results Distinct metabolic profiles were identified between activity and remission, independent of disease type. N-acetylglycoproteins and cholines of bound phospholipids emerged as predictive markers of disease activity. Altered levels of 4 of the 21 small molecules were also observed, including increased levels of phenylalanine and decreased glutamine, alanine and creatinine in active disease. Metabolic fingerprinting discriminated GCA from PMR in remission. GCA and PMR patients exhibited characteristic lipid alterations as a response and/or adverse effect of GC treatment. Correlation analysis showed that several identified biomarkers were further associated with acute phase reactants, CRP and ESR. Conclusion The NMR profile of serum metabolome could identify and propose sensitive biomarkers of inflammation. Metabolome alterations, following GC treatment, could provide predictors for future steroid-induced side effects. [ABSTRACT FROM AUTHOR]

Pyriform (or piriform) silk is a fibrous spider silk used in a composite material to attach web silks to substrates and disparate silk types together. Argiope argentata pyriform silk is formed from a protein with a central repetitive region consisting of a 234-amino acid unit (the "Py unit") repeated 21 times. We have previously shown that the Py unit behaves modularly, with a structured core of 6 α-helices that retains its structuring upon truncation of N- and C-terminal intrinsically disordered segments. Here, we apply solution-state nuclear magnetic resonance (NMR) spectroscopy to investigate the structured core of the Py unit. Based on 15N spin relaxation measurements and reduced spectral density mapping at two field strengths, the α-helical core of the Py unit exhibits minimal backbone motion beyond the tumbling of the globular domain except for one inter-helical linker that exhibits a notably higher degree of dynamics. Evaluation of rotational diffusion based on 15N spin relaxation and translational diffusion by pulsed field gradient diffusion NMR demonstrates that the core of the Py unit behaves as a compact structure, with hydrodynamic behaviour consistent with a well-packed protein. Pyriform silk protein undergoes a structural transformation upon conversion from the soluble-state to the fibrous-state, with a loss of α-helical content and gain of β-sheet content. The more dynamic segment we observe midway through the structured core of the Py core, especially in the context of the intrinsically disordered segments that flank the core, would provide an initiation point for decompaction, structural transformation, and/or intermolecular interactions. [ABSTRACT FROM AUTHOR]

Isocorydine is an aporphine alkaloid that is mainly produced via chemical synthesis and extracted from plants. Its hydrochloride has been authorized to be a prescription drug for clinical use. This study aims to discover potential alkaloidal metabolites from endophytic fungi associated with the plant. Endophytic fungi were subjected to solid-state fermentation (SSF) to investigate the production of isocorydine. An aporphine alkaloid was obtained from the metabolite of SSF with Aspergillus sydowii G12. Its chemical structure was deduced to be isocorydine according to the spectroscopic data of ESI-MS, 1H and 13C NMR spectroscopy. The fermentation conditions including substrate, fermentation temperature, and time were optimized. As a result, SSF with A. sydowii G12 using potato as substrate at 20 °C for 15 d could produce isocorydine with a high yield of 2.51 ± 0.09 mg/g. This paper is the first to report an approach to producing isocorydine from microorganisms instead of plants. [Display omitted] • Isocorydine (1) was obtained from the metabolite of SSF using A. sydowii G12. • Achieved SSF condition with A. sydowii G12 using potato substrate at 20°C for 15 d. • A high yield of 2.51 ± 0.09 mg/g can be obtained for the production of isocorydine. • This is the first report of an approach to produce isocorydine from microorganisms. [ABSTRACT FROM AUTHOR]

Phenolic hydroxyl groups in lignin are crucial for understanding its structure, reactivity, and potential applications. Various methods have been developed for the determining phenolic groups in lignin. This study focuses on the comparison of a simple, cost-effective, and time-efficient UV–vis ionization difference technique with the highly accurate 31P NMR spectroscopy for analyzing lignin samples of different origins and isolation methods. The results were carefully evaluated, and the strengths and limitations of each method were discussed. Two eco-friendly UV–vis approaches were proposed for a rapid and comprehensive evaluation of the total phenolic-OH groups: one using a strong alkaline solution for analyzing common types of technical lignins, and another employing multipoint wavelength calculations, effective for analyzing softwood lignins regardless of the extraction method. Additionally, the research highlighted the importance of selecting appropriate model phenolic compounds to accurately assess the phenolic hydroxyl group content in lignins using the UV–vis method. Offering straightforward and rapid analysis, with results closely aligning with 31P NMR data, this method is a promising alternative for routine analysis. [ABSTRACT FROM AUTHOR]

Supplemental Digital Content is Available in the Text. Using magnetic resonance spectroscopy, region-specific changes in glutamate and gamma-aminobutyric acid were measured at varying time points outside and during attacks in children and adolescents with migraine. In patients with migraine, an excitation–inhibition imbalance that fluctuates relative to attack onset has been proposed to contribute to the underlying pathophysiology of migraine, but this has yet to be explored in children and adolescents. This prospective, observational, cohort study examined glutamate and gamma-aminobutyric acid (GABA) levels across the phases of a migraine attack and interictally in children and adolescents using magnetic resonance spectroscopy. Macromolecule-suppressed GABA (sensorimotor cortex and thalamus) and glutamate (occipital cortex, sensorimotor cortex, and thalamus) were measured in children and adolescents (10-17 years) with a migraine diagnosis with or without aura 4 times over 2 weeks. Linear mixed-effects models examined changes in glutamate and GABA during the 72 hours leading up to, and after the onset of an attack. We found significant region-specific changes in glutamate and GABA. Specifically, sensorimotor GABA significantly increased leading up to the headache phase, whereas glutamate significantly decreased following the headache onset in the occipital cortex and the thalamus. Post hoc analyses examined the 24 hours leading up to or following the onset of the headache phase. In the 24 hours before the headache onset, sensorimotor glutamate, occipital glutamate, and thalamic GABA decreased. In the 24 hours post headache onset, sensorimotor glutamate continued to decrease. Our results suggest changes in glutamate and GABA that are consistent with the thalamocortical dysrhythmia hypothesis. These findings provide insight into developmental migraine pathophysiology and may open future avenues for treatment targets specific to children and adolescents. [ABSTRACT FROM AUTHOR]

Background: Cerebral syphilitic gummas are rare. However, numerous case reports on them have been published recently, consistent with the resurgence of syphilis and its accompanying atypical manifestations. We here present a patient with a cerebral syphilitic gumma and an unusual clinical course and review recent case reports. Case Presentation: A 49-year-old woman had a generalised seizure and was found by computed tomography and magnetic resonance imaging to have a brain mass that mimicked a brain abscess or malignant tumour. Further imaging with magnetic resonance spectroscopy and positron emission tomography did not contribute further to the differential diagnosis. Because treatment with ceftriaxone was ineffective, the lesion was resected. Serological tests on serum and cerebrospinal fluid were positive for syphilis and histopathological examination of the operative specimen revealed a syphilitic gumma. Antibiotic treatment is preferred over invasive interventions for cerebral syphilitic gumma. However, as in our case, radical resection is required when antibiotic treatment is ineffective. Conclusions: It has recently been reported that the prevalence of syphilis is increasing in older individuals, including in patients without HIV infection or prior treatment for early syphilis. Though advanced imaging and molecular biological techniques are often used to help make a diagnosis, they are of limited value. Because the clinical and imaging features are nonspecific, some neurosurgeons do not include cerebral syphilitic gummas in their differential diagnoses. It is vital that this possibility be considered when a patient has a tumour-like cerebral mass and serum positivity for syphilis. [ABSTRACT FROM AUTHOR]

In this work, we describe the synthesis and characterisation of the starting materials [Cp*IrCl2]2 and four new ruthenium(II) and iridium(III) complexes half sandwich, contain the fragments [(p-cymene)Ru]2+ and [Cp*Ir]2+; (Cp* = CpMe4Et) of stoichiometry: [Cp*IrCl2(2-aminopyridine)] (I), [Cp*IrCl2(4-aminopyridine)] (II), [Cp*IrCl2(adenine)] (III) and [(p-cymene)RuCl2(adenine)] (IV). The new compounds have been characterised by C, H, and N elemental analysis; infrared and 1H NMR spectroscopy with 1H–1H COSY, ESI/TOF mass spectrometry and thermogravimetry. A study of the cytotoxicity of these compounds against the Hela cell line was carried out, with results indicating a low activity. [ABSTRACT FROM AUTHOR]

Objectives: This study aimed to analyze the clinical and multimodal imaging manifestations of adult-onset neuronal intranuclear inclusion disease (NIID) patients and to investigate NIID-specific neuroimaging biomarkers. Methods: Forty patients were retrospectively enrolled from the Qilu Hospital of Shandong University. We analyzed the clinical and imaging characteristics of 40 adult-onset NIID patients and investigated the correlation between these characteristics and genetic markers and neuropsychological scores. We further explored NIID-specific alterations using multimodal imaging indices, including diffusion tensor imaging (DTI), magnetic resonance spectroscopy (MRS), and brain age estimation. In addition, we summarized the dynamic evolution pattern of NIID by examining the changes in diffusion weighted imaging (DWI) signals over time. Results: The NIID patients' ages ranged from 31 to 77 years. Cognitive impairment was the most common symptom (30/40, 75.0%), while some patients (18/40, 45.0%) initially presented with episodic symptoms such as headache (10/40, 25.0%). Patients with cognitive impairment symptoms had more cerebral white matter damage (χ2 = 11.475, P = 0.009). The most prevalent imaging manifestation was a high signal on DWI in the corticomedullary junction area, which was observed in 80.0% (32/40) of patients. In addition, the DWI dynamic evolution patterns could be classified into four main patterns. Diffusion tensor imaging (DTI) revealed extensive thinning of cerebral white matter fibers. The estimated brain age surpassed the patient's chronological age, signifying advanced brain aging in NIID patients. Conclusions: The clinical manifestations of NIID exhibit significant variability, usually leading to misdiagnosis. Our results provided new imaging perspectives for accurately diagnosing and exploring this disease's neuropathological mechanisms. [ABSTRACT FROM AUTHOR]

Sesquilignans PD is a natural phenylpropanoid compound that was isolated from Zanthoxylum nitidum var. tomentosum. In this study, we assessed the antitumor effect of PD on SK-Hep-1 and HepG2 cells and the underlying molecular mechanisms. The results revealed that PD markedly inhibited the proliferation and migration of both liver cancer cells. Moreover, PD induced apoptosis, autophagy, and reactive oxygen species (ROS) production in liver cancer cells. Notably, PD increased the protein levels of p-p38 MAPK and p-ERK1/2 in liver cancer cells. This is the first report on the anticancer effect of PD, which is mediated via increased ROS production and MAPK signaling activation. [ABSTRACT FROM AUTHOR]

The preliminary study revealed that the ethyl acetate eluate of Youngia japonica (YJ-E) could inhibit the expression of key proteins of p-p65, p-IκBα, p-IKKα/β, and p-AKT in LPS stimulated BV2 cell. Further phytochemical study led to the isolation of eight compounds from YJ-E, including one new sesquiterpene lactone. Their structures were elucidated by several spectroscopic data, and comparing the NMR data of known compound. In addition, all of the isolates were evaluated for the anti-inflammatory effect. As a result, compounds 3 and 4 distinctly attenuated the expressions of p-IκBα, p-p65, and p-AKT in LPS stimulated BV2 cell, respectively. [ABSTRACT FROM AUTHOR]

Five new glycosides, namely methyl 3-methoxybenzoate-4,5-di-O-β-D-glucopyranoside (1), (1aS,3aS,3R)-3-(4'-O-β-D-glucopyranosyl-3'-methoxyphenyl)-5,6-dioxa-bicyclo[3.3.0]octane-1-one (2), quinolin-4(1H)-one-3-O-β-D-glucopyranoside (3), 3-methoxy-propiophenone 4-O-(6'-β-D-xylopyranosyl)-β-D-glucopyranoside (4), methyl 3-methoxybenzoate 4-O-(6'-β-D-xylopyranosyl)-β-D-glucopyranoside (5), and one known compound, bambulignan B (6) were isolated from the culms of Phyllostachys nigra var. henonis. Their structures were determined using spectroscopic analysis. All compounds were evaluated for their DPPH radical scavenging activity. Compound 6 exhibited antioxidant activity with IC50 value of 59.5 μM (positive control, L-ascorbic acid, IC50 = 12.4 μM; 2,6-ditertbutyl-4-methyl phenol, IC50 = 11.8 μM). [ABSTRACT FROM AUTHOR]

In this study, the simultaneous synthesis of poly(methyl methacrylate-b-ε-caprolactone) block copolymer was fulfilled by atom transfer radical polymerization of methyl methacrylate and ring-opening polymerization of ε-caprolactone. The synthesis of poly(methyl methacrylate-b-ε-caprolactone) block copolymer was carried out by varying the amount of ε-caprolactone monomer, the amount of methyl methacrylate monomer, the amount of 2-(2-chloroethoxy) ethanol initiator, the amount of toluene solvent, and the polymerization time. The effects of these parameters on the reaction conditions were investigated. Fourier transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, and static light scattering methods were used for the characterization of the synthesized block copolymer. The surface images of the block copolymer were photographed with a scanning electron microscope instrument. In addition, thermal analysis of the synthesized block copolymer was performed using a thermogravimetric analyzer. These analyses prove the formation of the block copolymer structure. The simultaneous synthesis of poly(methyl methacrylate-b-ε-caprolactone) block copolymer was fulfilled by the atom transfer radical polymerization of methyl methacrylate and ring-opening polymerization of ε-caprolactone. The effects of the parameters on the polymerization reaction conditions were investigated. Thermal and spectroscopic measurements prove the formation of the block copolymer structure. [ABSTRACT FROM AUTHOR]

Glutathione (GSH) is a brain marker for oxidative stress and has previously been associated with cerebral amyloid deposition and memory decline. However, to date, no study has examined the links among GSH, sex, age, amyloid, and Apolipoprotein E (APOE) genotype in a large non-clinical cohort of older adults. We performed APOE genotyping, magnetic resonance spectroscopy (MRS) as well as simultaneous positron emission tomography with the radiotracer Flutemetamol (Amyloid-PET), in a group of older adults. The final analysis set comprised 140 healthy older adults (mean age: 64.7 years) and 49 participants with mild cognitive impairment (mean age: 71.4 years). We recorded metabolites in the posterior cingulate cortex (PCC) by a GSH-edited MEGAPRESS sequence. Structural equation modeling revealed that higher GSH levels were associated with female sex, but neither APOE- epsilon 4 carrier status nor age showed significant associations with GSH. Conversely, older age and the presence of an APOE4 allele, but not sex, are linked to higher global amyloid load. Our results suggest that the PCC shows sex-specific GSH alterations in older adults. • PCC GSH levels may be higher in women than in men. • PCC GSH levels were unrelated to local amyloid load. • PCC GSH levels were unrelated to the presence of an APOE epsilon 4 allele. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the metabolomic profile of T. molitor larvae reared on the following innovative growth substrates: wheat bran (control, CTRL); wheat bran supplemented with 12.5% w/w chestnut shell (TRT1); and wheat bran supplemented with 25% w/w chestnut shell (TRT2) for 14 days of trial. At the end of this experiment, larvae were transformed into insect meals for nutritional characterization. Nuclear Magnetic Resonance (NMR) spectroscopy was carried out to evaluate the metabolomic profile of organic acids, sugars, nitrogen bases and derivates, fatty acids, and other compounds. Chemical analysis showed an increased level of crude protein in TRT1 compared to CTRL and TRT2 (p = 0.0391). The metabolite profiles of TRT1 and TRT2 were similar to each other but distinct from those of the CTRL group. Notably, larvae enriched with chestnut shells revealed the presence of uracil, uridine, and glucose, while fumarate was absent. The enrichment analysis showed that in TRT1 and TRT2, the glyoxylate and dicarboxylate metabolism was more relevant compared to CTRL. These findings indicate that chestnut shell inclusion affects the larvae metabolism of T. molitor and demonstrates the effectiveness of NMR spectroscopy in revealing a relation between insect metabolism and growth substrate. [ABSTRACT FROM AUTHOR]

In this work, an aqueous two-phase system (ATPS) based on a green deep eutectic solvent (DES) and inorganic salt is presented and applied for the simultaneous determination of heterocyclic aromatic amines (HAAs) in the marinating juice via ultra performance liquid chromatography (UPLC). First, six different betaine-based DESs were prepared, and betaine/1,4-butanediol (Bet/Buta) was chosen as the suitable extractant for the ATPS. Their structures were confirmed via Fourier transform infrared (FT-IR) spectroscopy and proton nuclear magnetic resonance (1H-NMR) spectroscopy. Subsequently, the factors influencing the ATPS were systematically investigated, and the optimal extraction parameters were obtained with a trichloroacetic acid concentration of 5% (w/v), 0.2 g of Bet/Buta, 0.6 g of an inorganic salt (K2HPO4), an extraction time of 1 min and a centrifugation time of 2 min. Under optimal extraction conditions, good linearities were obtained, with the correlation coefficient (R) ≥ 0.9995. The inter- and intraday precisions were 2.4–4.9% and 2.9–5.3%, respectively. The recoveries for the targeted HAAs ranged between 91.6 and 111.9%. The limits of detection (LODs) of 5.0–14.6 ng/g were obtained. In contrast to the frequently used solid-phase extraction (SPE) technique, the developed DES‒ATPS method, which has higher accuracy and better precision, has advantages of simplicity, speed, good environmental friendliness and low cost per sample. Finally, it was utilized to determine the four selected HAAs in actual samples of marinating juice to evaluate its applicability. Analytical GREEnness metric (AGREE), a novel greenness assessment tool, was tested to verify that this work was a relatively green analytical procedure. These findings demonstrate that the green and efficient DES−ATPS composed of the Bet/Buta DES and K2HPO4 shows great potential for extracting and enriching HAAs or other harmful substances from liquid food in pilot or large-scale operations. [ABSTRACT FROM AUTHOR]

Diagnosing and classifying central nervous system tumors such as gliomas or glioblastomas pose a significant challenge due to their aggressive and infiltrative nature. However, recent advancements in metabolomics and magnetic resonance spectroscopy (MRS) offer promising avenues for differentiating tumor grades both in vivo and ex vivo. This study aimed to explore tissue-based metabolic signatures to classify/distinguish between low- and high-grade gliomas. Forty-six histologically confirmed, intact solid tumor samples from glioma patients were analyzed using high-resolution magic angle spinning nuclear magnetic resonance (HRMAS-NMR) spectroscopy. By integrating machine learning (ML) algorithms, spectral regions with the most discriminative potential were identified. Validation was performed through univariate and multivariate statistical analyses, along with HRMAS-NMR analyses of 46 paired plasma samples. Amongst the various ML models applied, the logistics regression identified 46 spectral regions capable of sub-classifying gliomas with accuracy 87% (F1-measure 0.87, Precision 0.82, Recall 0.93), whereas the extra-tree classifier identified three spectral regions with predictive accuracy of 91% (F1-measure 0.91, Precision 0.85, Recall 0.97). Wilcoxon test presented 51 spectral regions significantly differentiating low- and high-grade glioma groups (p < 0.05). Based on sensitivity and area under the curve values, 40 spectral regions corresponding to 18 metabolites were considered as potential biomarkers for tissue-based glioma classification and amongst these N-acetyl aspartate, glutamate, and glutamine emerged as the most important markers. These markers were validated in paired plasma samples, and their absolute concentrations were computed. Our results demonstrate that the metabolic markers identified through the HRMAS-NMR-ML analysis framework, and their associated metabolic networks, hold promise for targeted treatment planning and clinical interventions in the future. [ABSTRACT FROM AUTHOR]

Leukemia is a group of blood cancers that are classified in four major classes. Within these four classes, many different subtypes exists with similar origin, genetic mutations, and level of maturity, which can make them difficult to distinguish. Despite their similarities, they might respond differently to treatment, and therefore distinguishing between them is of crucial importance. A deranged metabolic phenotype (Warburg effect) is often seen in cancer cells, leukemia cells included, and is increasingly a target for improved diagnosis and treatment. In this study, hyperpolarized 13C NMR spectroscopy was used to characterize the metabolic signatures of the six leukemia cell lines ML‐1, CCRF‐CEM, THP‐1, MOLT‐4, HL‐60, and K562. This was done using [1‐13C]pyruvate and [1‐13C]alanine as bioprobes for downstream metabolite quantification and kinetic analysis on cultured cells with and without 2‐deoxy‐D‐glucose treatment. The metabolic signatures of similar leukemia subtypes could be readily distinguished. This includes ML‐1 and THP‐1, which are of the similar M4 and M5 AML subtypes, CCRF‐CEM and MOLT‐4, which are of the similar T‐ALL lineage at different maturation states, and HL‐60 and K562, which are of the closely related M1 and M2 AML subtypes. The data presented here demonstrate the potential of hyperpolarized 13C NMR spectroscopy as a method to differentiate between leukemia subtypes of similar origin. Combining this method with bioreactor setups could potentially allow for better leukemia disease management as metabolic signatures could be acquired from a single biopsy through repeated experimentation and intervention. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the metabolic changes in the kidneys in a murine adenine–diet model of chronic kidney disease (CKD). Kidney fibrosis is the common pathological manifestation across CKD aetiologies. Sustained inflammation and fibrosis cause changes in preferred energy metabolic pathways in the cells of the kidney. Kidney cortical tissue from mice receiving a control or adenine‐supplemented diet for 8 weeks (late inflammation and fibrosis) and 12 weeks (8 weeks of treatment followed by 4 weeks recovery) were analysed by 2D‐correlated nuclear magnetic resonance spectroscopy and compared with histopathology and biomarkers of kidney damage. Tissue metabolite and lipid levels were assessed using the MestreNova software. Expression of genes related to inflammation, fibrosis, and metabolism were measured using quantitative polymerase chain reaction. Animals showed indicators of severely impaired kidney function at 8 and 12 weeks. Significantly increased fibrosis was present at 8 weeks but not in the recovery group suggesting some reversal of fibrosis and amelioration of inflammation. At 8 weeks, metabolites associated with glycolysis were increased, while lipid signatures were decreased. Genes involved in fatty acid oxidation were decreased at 8 weeks but not 12 weeks while genes associated with glycolysis were significantly increased at 8 weeks but not at 12 weeks. In this murine model of CKD, kidney fibrosis was associated with the accumulation of triglyceride and free lactate. There was an up‐regulation of glycolytic enzymes and down‐regulation of lipolytic enzymes. These metabolic changes reflect the energy demands associated with progressive kidney disease where there is a switch from fatty acid oxidation to that of glycolysis. [ABSTRACT FROM AUTHOR]

The detection of a secondary inorganic phosphate (Pi) resonance, a possible marker of mitochondrial content in vivo, using phosphorus magnetic resonance spectroscopy (31P‐MRS), poses technical challenges at 3 Tesla (T). Overcoming these challenges is imperative for the integration of this biomarker into clinical research. To evaluate the repeatability and reliability of measuring resting skeletal muscle alkaline Pi (Pialk) using with 31P‐MRS at 3 T. After an initial set of experiments on five subjects to optimize the sequence, resting 31P‐MRS of the quadriceps muscles were acquired on two visits (~4 days apart) using an intra‐subjects design, from 13 sedentary to moderately active young male and female adults (22 ± 3 years old) within a whole‐body 3 T MR system. Measurement variability attributed to changes in coil position, shimming procedure, and spectral analysis were quantified. 31P‐MRS data were acquired with a 31P/‐proton (1H) dual‐tuned surface coil positioned on the quadriceps using a pulse‐acquire sequence. Test–retest absolute and relative repeatability was analyzed using the coefficient of variation (CV) and intra‐class correlation coefficients (ICC), respectively. After sequence parameter optimization, Pialk demonstrated high intra‐subject repeatability (CV: 10.6 ± 5.4%, ICC: 0.80). Proximo‐distal change in coil position along the length of the quadriceps introduced Pialk quantitation variability (CV: 28 ± 5%), due to magnetic field inhomogeneity with more distal coil locations. In contrast, Pialk measurement variability due to repeated shims from the same muscle volume (0.40 ± 0.09mM; CV: 6.6%), and automated spectral processing (0.37 ± 0.01mM; CV: 2.3%), was minor. The quantification of Pialk in skeletal muscle via surface coil 31P‐MRS at 3 T demonstrated excellent reproducibility. However, caution is advised against placing the coil at the distal part of the quadriceps to mitigate shimming inhomogeneity. [ABSTRACT FROM AUTHOR]

Functional magnetic resonance spectroscopy (fMRS) measures dynamic changes in metabolite concentration in response to neural stimulation. The biophysical basis of these changes remains unclear. One hypothesis suggests that an increase or decrease in the glutamate signal detected by fMRS could be due to neurotransmitter movements between cellular compartments with different T2 relaxation times. Previous studies reporting glutamate (Glu) T2 values have generally sampled at echo times (TEs) within the range of 30–450 ms, which is not adequate to observe a component with short T2 (<20 ms). Here, we acquire MRS measurements for Glu, (t) total creatine (tCr) and total N‐acetylaspartate (tNAA) from the visual cortex in 14 healthy participants at a range of TE values between 9.3–280 ms during short blocks (64 s) of flickering checkerboards and rest to examine both the short‐ and long‐T2 components of the curve. We fit monoexponential and biexponential Glu, tCr and tNAA T2 relaxation curves for rest and stimulation and use Akaike information criterion to assess best model fit. We also include power calculations for detection of a 2% shift of Glu between compartments for each TE. Using pooled data over all participants at rest, we observed a short Glu T2‐component with T2 = 10 ms and volume fraction of 0.35, a short tCr T2‐component with T2 = 26 ms and volume fraction of 0.25 and a short tNAA T2‐component around 15 ms with volume fraction of 0.34. No statistically significant change in Glu, tCr and tNAA signal during stimulation was detected at any TE. The volume fractions of short‐T2 component between rest and active conditions were not statistically different. This study provides evidence for a short T2‐component for Glu, tCr and tNAA but no evidence to support the hypothesis of task‐related changes in glutamate distribution between short and long T2 compartments. [ABSTRACT FROM AUTHOR]

Objective: The objective of this study was to identify sex differences in ntrahepatocellular (HCL) and intramyocardial lipids (MYCL) and cardiac function in participants with different grades of glucometabolic impairment and different BMI strata. Methods: Data from 503 individuals from 17 clinical experimental studies were analyzed. HCL and MYCL were assessed with 3T and 7T scanners by magnetic resonance spectroscopy. Cardiac function was measured with a 3T scanner using electrocardiogram‐gated TrueFISP sequences. Participants were classified as having normoglycemia, prediabetes, or type 2 diabetes. Three‐way ANCOVA with post hoc simple effects analyses was used for statistical assessment. Results: Consistent increases of HCL with BMI and deterioration of glucose metabolism, especially in female individuals, were detected. MYCL increased with BMI and glucose impairment in female individuals, but not in male individuals. Sex differences were found in cardiac function loss, with significant effects found among male individuals with worsening glucose metabolism. Myocardial mass and volume of the ventricle were higher in male individuals in all groups. This sex difference narrowed with increasing BMI and with progressing dysglycemia. Conclusions: Sex differences in HCL and MYCL may be associated with a higher cardiovascular disease risk observed in female individuals progressing to diabetes. Further studies are needed to elucidate possible sex differences with advancing glucometabolic impairment and obesity and their potential impact on cardiovascular outcomes. [ABSTRACT FROM AUTHOR]

Marine toxins, which are produced by diverse marine organisms, can pose various threats to marine ecosystems and human health. Understanding their chemical structures and compositions is an important and challenging stage in the process of devising effective strategies for their management and reduction. Nuclear magnetic resonance (NMR) spectroscopy, alongside mass spectrometry, has emerged as the core and universal technique to achieve this task. This review highlights the role of NMR in obtaining structural data and information on marine toxins, and discusses the practical applications of NMR in the characterization of toxins. The study describes key NMR techniques, including one- and two-dimensional experiments, and discusses case studies of NMR implemented to tackle detection sensitivity and the complexities of specific toxins. Finally, the study analyzes how NMR methodologies may be advanced to improve the structural analysis of marine toxins. [ABSTRACT FROM AUTHOR]