Nuclear Magnetic Resonance Spectra Research Articles

Enhanced Stability and Brightness through Co-Substitution: Promoting Plant Growth with Green-Excited Deep Red Phosphor Ca1-zSrzLi1-xMg2xAl3-xN4:yEu2.

The research utilized a strategy of chemical unit co-substitution, successfully developing a novel blue-green to green excited, deep red-emitting phosphor, Ca1-zSrzLi1-xMg2xAl3-xN4:yEu2+ (CLA-2xM-zS:yEu, 0≤x≤0.8, 0.003≤y≤0.01, 0≤z≤1), through the replacement of [Li-Al]4+ by [Mg-Mg]4+. This phosphor uniquely converts unusable green light to growth-enhancing deep red, optimizing it for outdoor agriculture. Doping with Sr creates traps, causing a redshift in emission peaks, as confirmed by 7Li nuclear magnetic resonance (NMR) spectra, indicating Li presence and lattice changes. Ca0.2Sr0.8Li0.5MgAl2.5N4:0.005Eu2+ (CLAM-0.8S) phosphor maintained high luminescence intensity under extreme conditions of 85°C/85% RH, demonstrating excellent photoluminescence performance and chemical stability, compared with conventional SrLi0.5MgAl2.5N4:0.005Eu2+ (SLMA) and SrLiAl3N4:0.005Eu2+(SLA). Experimental results surprised that the unique Ca0.2Sr0.8Li0.8Mg0.4Al2.8N4:0.005Eu2+ (CLA-0.4M-0.8S) prepared light-converting film, which is mainly excited by green light, demonstrated a 20% increase in optical density of Chlorella compared to the PP film and a remarkable 97.5% increase compared to the control group without any film. These findings suggest that this film has significant potential for applications in outdoor agriculture and other fields.

Nuclear Magnetic Resonance (NMR) and Density Functional Theory (DFT) Study of Water Clusters of Hydrogen-Rich Water (HRW)

The present study investigated the 1H Nuclear Magnetic Resonance (NMR) spectra of hydrogen-rich water (HRW) produced using the EVObooster device. The analyzed HRW has pH = 7.1 ± 0.11, oxidation–reduction potential (ORP) of (−450 ± 11) mV, and a dissolved hydrogen concentration of 1.2 ppm. The control sample was tap water filtered by patented technology. A 600 NMR spectrometer was used to measure NMR spectra. Isotropic 1H nuclear magnetic shielding constants of the most stable clusters (H2O)n with n from 3 to 28 have been calculated by employing the gauge-including-atomic-orbital (GIAO) method at the MPW1PW91/6-311+G(2d,p) density function level of theory (DFT). The HRW chemical shift is downfield (higher chemical shifts) due to increased hydrogen bonding. More extensive formations were formed in HRW than in control filtered tap water. The exchange of protons between water molecules is rapid in HRW, and the 1H NMR spectra are in fast exchange mode. Therefore, we averaged the calculated chemical shifts of the investigated water clusters. As the size of the clusters increases, the number of hydrogen bonds increases, which leads to an increase in the chemical shift. The dependence is an exponential saturation that occurs at about N = 10. The modeled clusters in HRW are structurally stabilized, suggesting well-ordered hydrogen bonds. In the article, different processes are described for the transport of water molecules and clusters. These processes are with aquaporins, fusion pores, gap-junction channels, and WAT FOUR model. The exponential trend of saturation shows the dynamics of water molecules in clusters. In our research, the chemical shift of 4.257 ppm indicates stable water clusters of 4–5 water molecules. The pentagonal rings in dodecahedron cage H3O+(H2O)20 allow for an optimal arrangement of hydrogen bonds that minimizes the potential energy.

HRMAS NMR for Studying Solvent-Induced Mobility of Polymer Chains and Metallocene Migration Into Low-Density Polyethylene (LDPE).

HRMAS (high-resolution magic angle spinning) nuclear magnetic resonance (NMR) spectroscopy of low-density polyethylene (LDPE) affords 1H and 13C NMR spectra with superior resolution. For acquiring HRMAS NMR spectra, the polymer is first swollen with representative organic solvents. Then, the samples are measured with a conventional solid-state NMR spectrometer in the wideline mode or at the low spinning speed of 2 kHz. Anisotropic interactions like CSA (chemical shift anisotropy) and dipolar interactions are reduced due to the additional mobility of the polymer chains in the presence of the solvent within the polymer network. The combined effect of this mobility and MAS leads to signals with substantially reduced halfwidths as compared to classic MAS of the dry polymer. With HRMAS, all signals of the polymer become visible, and the spectra can be used for a quick and easy assessment of the polymer swelling behavior in diverse solvents. Being able to characterize polymers on the molecular level, and identifying the solvents that penetrate the polymer network best, enables the study of post-synthesis modifications of the polymers. It is demonstrated by paramagnetic HRMAS that the metallocene nickelocene (Cp2Ni) penetrates the LDPE network along with the solvent and is homogeneously dispersed in the polymer. SEM images prove that the structure of the polymer is not altered by the presence of a solvent and Cp2Ni. The impact of the paramagnetic Cp2Ni on the 1H signal halfwidth and T1 time of LDPE is studied. HRMAS allows a quick assessment of metal complexes regarding their ability to penetrate the LDPE network and therefore supports future studies of catalytic polymer degradation.

Charge-driven first-order magnetic transition in NiPS3.

Cross-coupling among the fundamental degrees of freedom in solids has been a long-standing problem in condensed matter physics. Despite its progress using predominantly three-dimensional materials, how the same physics plays out for two-dimensional materials is unknown. Here, we show that using31P nuclear magnetic resonance (NMR), the van der Waals antiferromagnet NiPS3undergoes a first-order magnetic phase transition due to the strong charge-spin coupling in a honeycomb lattice. Our31P NMR spectrum near the N´eel ordering temperature TN= 155 K exhibits the coexistence of paramagnetic and antiferromagnetic phases within a finite temperature range. Furthermore, we observed a discontinuity in the order parameter at TNand the complete absence of critical behavior of spin fluctuations above TN, decisively establishing the first-order nature of the magnetic transition. We propose that a charge stripe instability arising from a Zhang-Rice triplet ground state triggers the first-order magnetic transition.

An expert system for species discrimination and grade identification of fish maw

Fish maw, derived from dried swim bladders of fish, is valued for its nutritional and medicinal properties, which has led to an increased market demand. However, price variability based on species and grades has results in unethical practices such as counterfeiting and mislabeling, highlighting the need for reliable quality authentication. To address this, an expert system using MATLAB software has been developed. This system employs nuclear magnetic resonance (NMR) technology and pattern recognition methods to identify fish maw species and classify their grade. The study analyzed ten species across three grades of fish maw, identifying 43 nutritional components from NMR spectra, including sugars, amino acids, fatty acids, organic acids, and vitamins. Univariate statistical analysis was integrated with multivariate statistical analyses, including principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA), and orthogonal partial least squares (OPLS-DA) using SIMCA software, to develop models for species and grades identification. A four-dimensional volcano map was constructed to highlight characteristic components of various fish maws, resulting in an NMR database for common fish maws. The expert system’s accuracy was validated with new samples, achieving 92.6% for species identification and 90.0% for grade classification. This study provides a valuable tool for the quality evaluation of fish maw and a scientific basis for market regulation.

Novel 5-Fluorouracil analogues versus perfluorophenyl ureas as potent anti-breast cancer agents: Design, robust synthesis, in vitro, molecular docking, pharmacokinetics ADMET analysis and dynamic simulations

To investigate the therapeutic potential of 5-Fluorouracil-based analogues, a straightforward synthetic technique was employed to synthesize a novel series of 5-arylurea uracil derivatives (AUFU01-03) and aryl-urea derivatives bearing perfluorophenyl (AUPF01-03). Reliable tools such as infrared (IR), Nuclear Magnetic Resonance (NMR) spectra, and elemental analyses were utilized to confirm the chemical structures and purity of these compounds. In comparison to healthy noncancerous control skin fibroblast cells (BJ-1), we examined the antiproliferative efficacy of compounds (AUFU01-03) and (AUPF01-03) against specific human malignant cell lines of the breast (MCF-7), and colon (HCT-116). Based on the MTT experiment results, compounds AUFU03 and AUPF01-03 possessed highly cytotoxic effects. Among these, cytotoxicity was demonstrated by compounds AUPF01-03 with IC50 values (AUPF01, IC50 = 167 ± 0.57 µM, AUPF02, IC50 = 23.4 ± 0.68 µM and AUPF03, IC50 = 28.8 ± 1.13 µM, respectively, on MCF-7), relative to 5-Fluorouracil as reference drug (IC50 = 160.7 ± 0.22 µM). Compound AUPF01 showed safety on BJ-1 cells up to a concentration of 100 µM (% cytotoxicity = 3.9 ± 0.42 %), so AUPF01 was selected for further studies. At the gene, the expression levels of BCL-2 gene were decreased significantly in MCF-7 + 5-FU and reached the lowest level in MCF-7 + AUPF01. In contrast, the expression levels of pro-apoptotic genes (p53 and BAX) were increased in MCF-7 + 5-FU, and reached a significantly higher level in MCF-7 + AUPF01. Apoptosis/necrosis assays demonstrated that AUPF01 induced S and G2/M phase cell cycle arrest in MCF-7 cells. Moreover, the efficacy of these compounds against anti-cancer protein receptors was assessed using molecular docking. The results indicated that compound AUPF01 exhibited high binding energies, effectively interacting with the active sites of crucial proteins such as EGFR, CDK2, ERalfa, BAX1, BCL2, and P53. These interactions involved a diverse range of chemical bonding types, suggesting the potential of these substances to inhibit enzyme activities. Moreover, computational ADMET analyses of these compounds demonstrated compliance with Lipinski’s criteria, indicating favorable physicochemical properties. Additionally, molecular dynamics (MD) simulations revealed stable complexes of AUPF01 with EGFR, CDK2, ERalfa, BAX1, BCL2, and P53, as evidenced by (RMSD) values, RMSF values, and (SASA) values for the respective complexes.

Synthesis and characterization of new organometallic lanthanides metal complexes for photodynamic therapy

New Schiff base ligand: 4-methoxy salicaldhyde-2-2-phenyl-hydrazono acetaldehíyde prepared by facile method. The molecular structures characterized by elemental analysis and proton magnetic resonance spectra (1H-NMR spectra). This spectra at the chemical shifts (3.5–10.39 ppm) confirmed the types and the numbers of protons. The sharp melting point at the range 110–112 °C confirmed purity. New optically active metal (samarium, terbium and gadolinium) complexes of the Schiff base synthesized in a one pot reaction. Vibrational IR spectra confirmed functional groups. Scanning electron microscopy micrographs confirmed that the modified microstructure of the metal complexes differed in morphology than the ligand. Powder X-ray diffraction patterns confirmed good crystalline structure. The optically activity of the solid metal complexes confirmed from electronic absorption spectra. The UV absorbance band at the wavelength range 280–390 nm and the intense phosphorescence bands up to 830 nm enabled application in photo dynamic therapy for apoptosis cancer cells by conversion triplet oxygen in the tissues into reactive singlet oxygen. Low charge transfer energy: 2.59–2.61 eV, high molar extinction coefficients (ε) at the order of magnitude \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\:{10}^{6}$$\\end{document} M− 1 cm− 1 and the intense phosphorescence bands reflected good photodynamic activity. The metal complexes are thermally stable.

MetaboScope: A statistical toolbox for analyzing 1H nuclear magnetic resonance spectra from human clinical studies

Abstract Motivation Metabolic phenotyping, using high-resolution spectroscopic molecular fingerprints of biological samples, has demonstrated diagnostic, prognostic, and mechanistic value in clinical studies. However, clinical translation is hindered by the lack of viable workflows and challenges in converting spectral data into usable information. Results MetaboScope is an analytical and statistical workflow for learning, designing and analyzing clinically relevant 1H nuclear magnetic resonance data. It features modular pre-processing pipelines, multivariate modeling tools including principal components analysis (PCA), orthogonal-projection to latent structure discriminant analysis, and biomarker discovery tools (multiblock PCA and statistical spectroscopy). A simulation tool is also provided, allowing users to create synthetic spectra for hypothesis testing and power calculations. Availability and implementation MetaboScope is built as a pipeline where each module accepts the output generated by the previous one. This provides flexibility and simplicity of use, while being straightforward to maintain. The system and its libraries were developed in JavaScript and run as a web app; therefore, all the operations are performed on the local computer, circumventing the need to upload data. The MetaboScope tool is available at https://www.cheminfo.org/flavor/metabolomics/index.html. The code is open-source and can be deployed locally if necessary. Module notes, video tutorials, and clinical spectral datasets are provided for modeling. Supplementary information Supplementary data are available at Bioinformatics Advances online.

Semi-Preparation and X-ray Single-Crystal Structures of Sophocarpine-Based Isoxazoline Derivatives and Their Pesticidal Effects and Toxicology Study.

Recently, research and development of novel pesticides from natural plant products have received much attention. To accelerate the application of sophocarpine as the agrochemical candidate, a series of novel sophocarpine-based isoxazoline derivatives were prepared by the 1,3-dipolar [2 + 3] cycloaddition reaction of sophocarpine with different chloroximes. Their structures were well characterized by high-resolution mass spectra, infrared spectra, and proton/carbon-13 nuclear magnetic resonance spectra. Eight steric configurations of compounds 5a, 5e', 5f, 5g, 5h, 5i, 5r, and 5u' were further determined by X-ray single-crystallography. Against Aphis citricola Van der Goot, compounds 5n (LD50: 0.032 μg/nymph) and 5o (LD50: 0.024 μg/nymph) exhibited greater than 3.7- and 4.9-fold potent aphicidal activity compared to sophocarpine (LD50: 0.118 μg/nymph). Against Tetranychus cinnabarinus Boisduval, derivative 5g displayed the most promising acaricidal activity with the LC50 value of 0.247 mg/mL, which was 14.2-fold that of sophocarpine. Compounds 5d and 5g also exhibited good control efficacy against T. cinnabarinus. Scanning electron microscopy images indicated that compound 5g can destroy the mite cuticle layer. These results will provide the foundation for the structural modification and use of sophocarpine derivatives as agrochemicals in the future.

Application of Two-Dimensional NMR for Quantitative Analysis of Viscosity in Medium–High-Porosity-and-Permeability Sandstones in North China Oilfields

The viscosity of crude oil plays a pivotal role in the exploration and development of oil fields. The predominant reliance on laboratory measurements, which are constrained by manual expertise, represents a significant limitation in terms of efficiency. Two-dimensional nuclear magnetic resonance (NMR) logging offers a number of advantages over traditional methods. It is capable of providing faster measurement rates, as well as insights into fluid properties, which can facilitate timely adjustments in oil and gas development strategies. This study focuses on the loose sandstone reservoirs with high porosity and permeability containing heavy oil in the Huabei oilfield. Two-dimensional nuclear magnetic resonance (NMR) measurements and analyses were conducted on saturated rocks with different-viscosity crude oils and varying oil saturation levels, in both natural and artificial rock samples. This study elucidates the distribution patterns of different-viscosity crude oils within the two-dimensional NMR spectra. Furthermore, the T1 and T2 peak values of the extracted oil signals were employed to establish a model correlating oil viscosity with NMR parameters. Consequently, a criterion for determining oil viscosity based on two-dimensional NMR was formulated, providing a novel approach for estimating oil viscosity. The application of this technique in the BQ well group of the Huabei oilfield region yielded an average relative error of 15% between the actual oil viscosity and the computed results. Furthermore, the consistency between the oil types and the oil discrimination chart confirms the reliability of the method. The final outcomes meet the precision requirements for practical log interpretation and demonstrate the excellent performance of two-dimensional nuclear magnetic resonance (NMR) logging in calculating oil viscosity. The findings of this study have significant implications for subsequent exploration and development endeavors in the research area’s oilfields.

Solid-State Lithium Batteries with In Situ Polymerized Acrylate-Based Electrolytes Capable of Electrochemically Stable Operation at 100 °C.

Solid polymer electrolytes (SPEs) typically consist of salts with mobile anions that could cause instabilities and parasitic side reactions in solid-state lithium (Li) batteries. To address this challenge, single-Li-ion conducting (SLIC) SPEs, where anions of Li salts are covalently attached to the polymer backbone, have been utilized to reduce the number of mobile anions. This approach improves the cationic transference number but is accompanied by a loss of ionic conductivity. In this work, we investigate a synergetic approach of using both a polymerizable SLIC salt and a conventional Li salt in a polymer matrix by in situ polymerization of the poly(propylene glycol) acrylate (PPGA) monomer. The synthesized hybrid SPEs show a high ionic conductivity of up to ∼2 × 10-4 S cm-1 and a relatively high Li-ion transference number of ∼0.4. With a significantly reduced fraction of mobile anions in the combined salt SPE, in situ polymerized SPE cells with a LiFePO4 (LFP) cathode achieve a stable performance for over 100 cycles at temperatures as high as 100 °C, which is unattainable with conventional Li salts or electrolytes. Furthermore, solid-state nuclear magnetic resonance spectra provide additional insights into differences in Li nucleus environments and emphasize a reduction in activation energy for hybrid SPEs due to their more open structure. This study opens the path for the fabrication of high-performance solid polymer Li batteries capable of operating at high temperatures using commercial battery fabrication equipment, as in situ polymerized acrylate-based polymers provide drop-in compatibility with conventional battery production, ease of acrylate polymerization, and inexpensive, facile SPE chemistry. We expect that further tuning of the acrylate-based SPE composition may allow further increases in its conductivity without sacrificing its electrochemical stability or mechanical properties.

Toward Absolute Quantification of Soluble Proteins via Proton Nuclear Magnetic Resonance Spectroscopy: Total Protein Concentration in Blood Plasma.

For absolute protein quantification using nuclear magnetic resonance (NMR) spectroscopy, we considered proteins as homopolymers and effective amino acid (AA) residues (AAREff) as monomer units. For diverse classes of proteins, we determined the AAREff molecular weight as 111.5 ± 3.2 Da and the number of hydrogens per AA as 7.8 ± 0.2. Their ratio of 14.3 ± 0.3 (g/LP)/(mol/LH) remains constant across various protein classes and is equivalent to Kjeldahl's nitrogen-to-protein conversion constant of 5.78 ± 0.29 gN/gP. By analogy to the Kjeldahl method, we suggest that the total integral of a 1H NMR solution protein spectrum could be used for total protein quantification. We synthesized low-resolution protein spectra from the weighted sums of individual AA spectra and compared them with experimental spectra. In the methyl region, the ratio of the protein mass to the total number of protons in the synthetic spectra (corrected for the chemical shift mismatch) was ∼1 (mg/mL)/mM, which agrees with an earlier reported experimental ratio for urine (1.05 ± 0.06 (mg/mL)/mM). For human blood plasma, in the methyl region, we found empirical ratios of 1.115 ± 0.006 (mg/mL)/mM (using 96 patient samples) and 1.121 ± 0.011 (mg/mL)/mM for the NIST plasma standard. This numerical agreement points to universal conversion constants, i.e., protein mixtures with unknown compositions could be quantified without the need for calibration standards by measuring the millimolar proton concentration within the methyl region of the NMR spectrum using the same conversion constant.

Polyene Macrolactams from Marine Micromonospora sp.

Introduction: Three novel macrolactams, FW8-1 (1), FW8-4 (2), and FW60-20 (3), were isolated from a culture of Micromonospora sp. The structures of these compounds were elucidated using Mass Spectrometry (MS) and comprehensive Nuclear Magnetic Resonance (NMR) analyses. Methods: The relative configurations of compounds 1-3 were assigned through theoretical calculations of their NMR spectra. objective: The objective is to obtain PMLs with novel structures and to characterize and evaluate them. Results: The isolation and determination of the relative configurations of these macrolactams have provided fresh perspectives on the biosynthetic pathways, leading to the formation of polyene macrolactams. Conclusion: Further, virtual screening and bioactivity predictions have suggested compounds 1-3 to possess potential anti-tumor, anti-inflammatory, and neuroprotective properties.

Glucose hydrochar consists of linked phenol, furan, arene, alkyl, and ketone structures revealed by advanced solid-state nuclear magnetic resonance

The molecular structure of hydrochars produced from 13C-enriched glucose under various conditions has been elucidated based on advanced one- and two-dimensional (2D) 1H-13C and 13C–13C solid-state nuclear magnetic resonance (NMR) with spectral editing. Regardless of synthesis conditions, hydrochars consist mostly of oxygen-substituted arene rings (including diphenols) and furans connected by alkyl linkers rich in ketones. Cross-linking nonprotonated and methyne (C-H) alkyl carbons have been identified through spectrally edited 2D NMR. Alkenes and ‘quaternary’ C-O are observed only at low synthesis temperature, while some clusters of fused arene rings are generated at high temperature. Hydrochar composition is nearly independent of reaction time in the range from 1 to 5 h. Equilibration of 13C magnetization within 1 s shows that the materials are homogeneous on the 5-nm scale, refuting core–shell models of hydrochar microspheres. While furan C-O carbons bonded to alkyl groups or ketones show distinctive cross peaks in 2D NMR, phenolic C-OH is observed unambiguously by hydroxyl-proton selection. While methylene-linked furan rings are fairly common, the signal previously assigned to furan Cα-Cα linkages is shown to arise from abundant, stable catecholic ortho-diphenols, whose HO-C=C-OH structure is proved by 2D13C–13C NMR after hydroxyl-proton selection. Quantitative 13C NMR spectra of low- and high-temperature hydrochars have been matched by chemical-shift simulations for representative structural models. Mixed phenol and furan rings connected by ketones and alkyl linkers provide good fits of the experimental spectra, while literature models dominated by large clusters of fused rings and with few phenols or alkyl-linked ketones do not.

Metabolomic Analysis of Histological Composition Variability of High-Grade Serous Ovarian Cancer Using 1H HR MAS NMR Spectroscopy.

In this work, the HR MAS NMR (high-resolution magic-angle spinning nuclear magnetic resonance) spectroscopy technique was combined with standard histological examinations to investigate the metabolic features of high-grade serous ovarian cancer (HGSOC) with a special focus on the relation between a metabolic profile and a cancer cell fraction. The studied group consisted of 44 patients with HGSOC and 18 patients with benign ovarian tumors. Normal ovarian tissue was also excised from 13 control patients. The metabolic profiles of 138 tissue specimens were acquired on a Bruker Avance III 400 MHz spectrometer. The NMR spectra of the HGSOC samples could be discriminated from those acquired from the non-transformed tissue and were shown to depend on tumor purity. The most important features that differentiate the samples with a high fraction of cancer cells from the samples containing mainly fibrotic stroma are the increased intensities in the spectral regions corresponding to phosphocholine/glycerophosphocholine, phosphoethanolamine/serine, threonine, uridine nucleotides and/or uridine diphosphate (UDP) nucleotide sugars. Higher levels of glutamine, glutamate, acetate, lysine, alanine, leucine and isoleucine were detected in the desmoplastic stroma within the HGSOC lesions compared to the stroma of benign tumors. The HR MAS NMR analysis of the metabolic composition of the epithelial and stromal compartments within HGSOC contributes to a better understanding of the disease's biology.

Stretch-Induced Ordering of Prochiral Dimethyl Sulfoxide in Anisotropic Hydrogels Analysed by 1H and 2H Nuclear Magnetic Resonance.

Nuclear spins in small molecules dissolved in stretched hydrogels typically have population-averaged residual interactions. The nuclear magnetic resonance (NMR) spectra of these systems often show additional peaks and splittings compared with free solutions. Residual dipolar couplings (RDCs) and quadrupolar couplings (RQCs) are observed for guest1H or2H nuclear spins, respectively. Dimethyl sulfoxide (DMSO) is an exquisitely sensitive probe of such biologically relevant environments since it is prochiral and becomes effectively chiral when embedded in anisotropic gelatin-based hydrogels. Measured1H RDCs and2H RQCs were used to estimate bond order parametersover a wide range of stretching extents.At the largest extent of stretching, the2H splittings were-73.0 and-9.4 Hz, similar to those found for guest molecules in liquid crystals. Inhomogeneous line broadening of the2H resonances was related to the size of the RQC due to a spatial distribution of RQCs, which was revealed using a one-dimensional slice selective imaging experiment along the stretching direction.1H NMR spectra exhibited homogeneous line broadening, with resonance integrals that indicated concealed multiplet structure. Understanding molecular bond ordering in mechanically oriented environments provides a conceptual framework for investigating more complex systems including zeolites and those foundin vivo.

Maleic anhydride esterified potato starch as the binder in silicon nanoparticles anode for lithium-ion batteries

Potato starch is a natural carbohydrate binder. Starch has hydroxyl groups that can promote interaction with silicon particles using multifaceted hydrogen bonds. Maleic anhydride esterified potato starch can produce a binder that maintains the cycle stability of lithium-ion batteries. Fourier-transform infrared spectroscopy spectra show wavelengths of 1776 cm−1 and 1855 cm−1. Thermal gravimetric analysis curves decreased in weight percent by 80 % at 286 °C. Carbon-13 nuclear magnetic resonance spectra show high peaks at 3.37 ppm, 3.65 ppm, 4.56 ppm, 5.09 ppm, and 6.22 ppm. Scanning electron microscope images show that the morphological change in esterified starch was due to the increased length of starch and the maleic anhydride grafted onto the starch granules. The cyclic voltammetry curve shows that the reduction peak is around 0.16 V, and the oxidation peak is around 0.38 V and 0.56 V. Nyquist plots show a small half circle, indicating that the electrode's solid-electrolyte interphase layer is low. The cycling performance shows a capacity of 1950 mAh/g.

Anion and Cation Dynamics in Mixed-Anion Hydroborate Na3(BH4)(B12H12): 1H, 11B, and 23Na NMR Studies

Sodium borohydride-closo-hydroborate Na3(BH4)(B12H12) exhibits high room-temperature ionic conductivity and high electrochemical stability. To study the dynamical properties of this mixed-anion compound at the microscopic level, we have measured the 1H, 11B, and 23Na nuclear magnetic resonance spectra and nuclear spin-lattice relaxation rates over the temperature range of 8–573 K. Our 1H and 11B spin-lattice relaxation measurements have revealed two types of reorientational jump motion. The faster motional process attributed to reorientations of the [BH4]− anions is characterized by an activation energy of 159 meV, and the corresponding reorientational jump rate reaches ~108 s−1 near 130 K. The slower process ascribed to reorientations of the larger [B12H12]− anions is characterized by an activation energy of 319 meV, and the corresponding reorientational jump rate reaches ~108 s−1 near 240 K. The results of the 23Na nuclear magnetic resonance measurements are consistent with the fast long-range diffusion of Na+ ions in Na3(BH4)(B12H12). The diffusive jump rate of Na+ is found to reach ~104 s−1 at 300 K and ~8 × 108 s−1 at 530 K. A comparison of these jump rates with the ionic conductivity data suggests the importance of correlations between diffusing ions.

B-280 Nmr-based biomaker measurement determines high-dose methotrexate elimination rates in lymphoma and leukemia treatment

Abstract Background The cytotoxic methotrexate (MTX) is used in high doses in lymphoma and acute lymphocytic leukemia (ALL) treatment. A therapeutic plasma dose range is crucial to minimize MTX accumulation and prolonged exposure, which can lead to myelosuppression and other adverse effects. Determining MTX elimination prior to drug administration is difficult, given its non-linear clearance. Here we present a model to predict MTX elimination rates based on metabolite measurement in patients receiving high-dose methotrexate, using nuclear-magnetic resonance (NMR) spectroscopy. Methods A series of 26 residual sera from patients receiving MTX infusions as per treatment protocols for CNS lymphoma (MATRIX protocol, 3.5 g/m2 over four hours) and ALL (GMALL protocol, 1.5 g/m2 over 24 hours) were collected from patients at the University Hospital Regensburg at four timepoints (t0, t24, t42, and t48). Serum was NMR-measured in five replicates. NMR spectra for each sample were characterized and relevant parameters extracted. First order elimination constants were modeled for two MTX dosage regimes (<4 g, ≥4 g) using characterized NMR features from samples measured at t0. Results Metabolomic and lipidomic biomarkers measured at baseline (t0) were able to accurately predict MTX elimination rate constant k, determined by fitting MTX levels at a t24, t42, and t48, using first order c(t)∼c0*e(-kt) kinetic function (>4 g: R2 = 0.475, p-value < 0.05; ≤4 g: R2 = 0.918, p-value < 0.01) (Fig. A). Results were cross-validated with five-time repeated three-fold cross-validation. Performance values are given as means of the folds. Conclusions NMR-measured biomarkers can predict dose-dependent MTX elimination rates in patients receiving high-dose MTX, presenting a novel method to predict MTX clearance, allowing for personalized dose-monitoring and minimization of adverse events. Validation with a larger cohort is required.

Physicochemical, structural, and biological properties of novel water-soluble polysaccharide derived from the Tunisian Hammada scoparia plant and its application on beef meat preservation

This work aims to characterize a novel water-soluble polysaccharide from Hammada scoparia leaves named PSP. The Infrared (FT-IR) and nuclear magnetic resonance (NMR) spectra confirmed the presence of different polysaccharide functional bands. The High-Performance Liquid Chromatography (HPLC) analysis identified a heteropolysaccharide composed of two monosaccharides. A semi-crystalline structure of PSP was proved using the X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM) analysis. The evaluation of the antioxidant activity revealed an interesting potential to prevent oxidative stress.Additionally, PSP showed interesting functional propreties such as good oil and water retention abilities, higher foaming stability, and higher emulsifying capacity and stability. However, the effect of PSP on the oxidation of lipids in the ground beef meat was established during nine days at 4 °C. Obtained data revealed a significant decrease in malondialdehyde levels, inhibition of metmyoglobin (MetMb) accumulation, and significant inhibition of microbial growth compared with the control sample during storage. Moreover, incorporating PSP in minced meat proved color pH and moisture stability. Overall, the findings in the present study confirmed that PSP could be considered a natural bioactive polymer for food applications.