Nuclear Magnetic Resonance Methods Research Articles

Estimation of unfrozen water content of saturated sandstones using nuclear magnetic resonance, mercury intrusion porosimetry, and ultrasonic tests

The unfrozen water content (UWC) is a crucial parameter that affects the strength and thermal properties of rocks in relation to engineering construction and geological disasters in cold regions. In this study, three different methods were employed to test and estimate the UWC of saturated sandstones, including nuclear magnetic resonance (NMR), mercury intrusion porosimetry (MIP), and ultrasonic methods. The NMR method enabled the direct measurement of the UWC of sandstones using the free induction decay (FID). The MIP method was used to analyze the pore structures of sandstones, with the UWC subsequently calculated based on pore ice crystallization. Therefore, the MIP test constituted an indirect measurement method. Furthermore, a correlation was established between the P-wave velocity and the UWC of these sandstones based on the mixture theory, which could be employed to estimate the UWC as an empirical method. All methods demonstrated that the UWC initially exhibited a rapid decrease from 0 °C to −5 °C and then generally became constant beyond −20 °C. However, these test methods had different characteristics. The NMR method was used to directly and accurately calculate the UWC in the laboratory. However, the cost and complexity of NMR equipment have precluded its use in the field. The UWC can be effectively estimated by the MIP test, but the estimation accuracy is influenced by the ice crystallization process and the pore size distribution. The P-wave velocity has been demonstrated to be a straightforward and practical empirical parameter and was utilized to estimate the UWC based on the mixture theory. This method may be more suitable in the field. All methods confirmed the existence of a hysteresis phenomenon in the freezing-thawing process. The average hysteresis coefficient was approximately 0.538, thus validating the Gibbs–Thomson equation. This study not only presents alternative methodologies for estimating the UWC of saturated sandstones but also contribute to our understanding of the freezing-thawing process of pore water.

Scavenging of Superoxide Radical Anion by Fluorinated Organosilicon Additives

We have explored a set of structurally related fluorinated and non-fluorinated organosilicon additives and quantified their rates of reaction with the superoxide radical anion O2 •−. using rapid-scan cyclic voltammetry. Absolute reaction rate measurements in acetonitrile solvent show that O2 •− reacts with the fluorinated OS compounds with bimolecular rate constants k BM more than 1000x larger than k BM for the reaction between O2 •− and ethylene carbonate. We further identified the products of reaction of a model OS compound using multiple nuclear magnetic resonance (NMR) methods and with gas chromatography/mass spectroscopy. Chemical analysis measurements show that addition of potassium superoxide KO2 to a model fluorinated OS compound produces only one product. Our results indicate that that OS compounds improve battery performance by rapidly scavenging O2 •− in a way that produces a stable product and reduces or eliminates the competing chemical pathways associated with carbonate breakdown. These results provide new insights into how chemical structure impacts critical chemical reactions and may guide the design of new additives that further improve battery safety and stability.

Radio frequency pulse marking of nuclear magnetization for magnetic flow metering: The impact of the flow profile

This study explores how magnetization manipulation occurs in a flowing medium over a pipe geometry using nuclear magnetic resonance methods. In particular, the experimental conditions on radio frequency pulsing and the signal detection are studied in an ultra-low frequency regime of a few kilohertz. An analytical model of the magnetization preparation is presented, which calculates the magnetization distribution of an excited flowing segment. The effective flip angle distribution is mapped to simulate the temporal development of the magnetization in the segment. The simulation results are compared to the experimental data from a flow metering setup. As a result, the quantitative impact of the flow profile on the magnetic signal is shown.

Rapid simulation of two-dimensional spectra with correlated anisotropic dimensions.

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.

Influence of Reservoir Microstructure on the State of Residual Oil According to Nuclear Magnetic Resonance (NMR) Spectroscopy

The influence of core properties on the state of residual oil in the process of oil displacement by water at the micro level is investigated. The pore size distribution, core permeability, dynamics and morphology of residual oil were studied. The analysis of the available experimental approaches to the study of the properties of the core and residual oil in the core samples showed that the existing methods do not provide complete information about the studied parameters. To solve these problems, it is proposed to use a combination of innovative relaxation-diffusion spectroscopy technology of nuclear magnetic resonance with traditional technology. A combination of mercury injection and nuclear magnetic resonance is used to measure the pore size distribution. The core permeability was determined using the nuclear magnetic resonance method. Two-dimensional nuclear magnetic resonance spectroscopy makes it possible to study the microscopic state of residual oil in an undisturbed core during the displacement process. With the help of the proposed methodology, a core study of the Shengli deposit in China was carried out. Pore size distributions were obtained, permeability and residual oil saturation at different stages of displacement were studied. Four types of residual oil are distinguished: strip-shaped (island), film, mesh, continuous. The influence of permeability on the fraction content of different types of residual oil in the process of displacement is shown. The research results demonstrate the influence of the pore space structure and wettability on the state of residual oil.

Ultrahigh Bifunctional Photocatalytic CO2 Reduction and H2 Evolution by Synergistic Interaction of Heteroatomic Pt-Ru Dimerization Sites.

Diatomic-site catalysts (DASCs) inherit the excellent performance of single-atom catalysts (SACs) by utilizing two adjacent atomic metal species to achieve functional complementarity and synergistic effects that improve the carbon dioxide reduction reaction (CO2RR) and H2 evolution reaction (HER) kinetics. Herein, we report a method to further improve the catalytic efficiency of Pt by using Pt and Ru single atoms randomly anchored on a g-C3N4 surface, yielding partial Pt-Ru dimers. The synthesized catalyst exhibits extraordinary photocatalytic activity and stability in both the CO2RR and HER processes. In-depth experimentation, the pH-dependent chemical exchange saturation transfer (CEST) imaging nuclear magnetic resonance (NMR) method, and theoretical analyses reveal that the excellent performance is attributed to orbital coupling between the Pt atoms and the neighboring Ru atoms (mainly dxy and dxz), which decreases the orbital energy levels and weakens the bond strength with intermediates, resulting in improved CO2RR and HER performance. This study successfully applies the pH-dependent CEST imaging NMR method to catalytic reactions, and CO2 adsorption is directly observed using CEST 2D imaging maps. This work presents significant potential for a variety of catalytic reaction applications by systematically designing bimetallic dimers with higher activity and stability.

Physicochemical and structural evaluation of natural products as a potential source for viral disease treatment

This research article aims to investigate six selected medicinal plants of Achillea millefolium (Yarrow), Alkanet, Rumex patientia (Patience dock), Dill, Tarragon, and Sweet fennel including some principal chemical compounds of achillin, alkannin, cuminaldehyde, dillapiole, estragole and fenchone. The definitive roles of these medicinal plants in Omicron treatment have been investigated through quantum mechanics and molecular mechanic methods. However, given the unprecedented challenges faced should be given a fair amount of consideration for contribution during this pandemic. In this work, it has been investigated the compounds of achillin, alkannin, cuminaldehyde, dillapiole, estragole and fenchone as a probable anti pandemic Omicron receptor derived from medicinal plants. Anti-Omicron drugs through the hydrogen bonding through physico-chemical properties of medicinal ingredients bound to the database amino acids fragment of Tyr-Met-His as the selective zone of the Omicron have been estimated with infrared (IR) and nuclear magnetic resonance (NMR) methods. A comparison of these structures has provided new insights for the design of substrate-based anti-targeting Omicron. Finally, five medicinal ingredients of achillin, alkannin, cuminaldehyde, dillapiole, and estragole bound to TMH have conducted to a Monte Carlo (MC) simulation for evaluating the absorbance of these inhibitor-active site complexes. Here, we used the network pharmacology, metabolite analysis, and molecular simulation to figure out the biochemical basis of the health-raising influence of medicinal plants. This research article peruses the drug ability, metabolites and potential interaction of some medicinal plants with Coronavirus-induced pathogenesis.

A Facile NMR Method for Pre-MRI Evaluation of Trigger-Responsive T1 Contrast Enhancement.

There is a growing interest in developing paramagnetic nanoparticles as responsive magnetic resonance imaging (MRI) contrast agents, which feature switchable T1 image contrast of water protons upon biochemical cues for better discerning diseases. However, performing an MRI is pragmatically limited by its cost and availability. Hence, a facile, routine method for measuring the T1 contrast is highly desired in early-stage development. This work presents a single-point inversion recovery (IR) nuclear magnetic resonance (NMR) method that can rapidly evaluate T1 contrast change by employing a single, optimized IR pulse sequence that minimizes water signal for "off-state" nanoparticles and allows for sensitively measuring the signal change with "switch-on" T1 contrast. Using peptide-induced liposomal gadopentetic acid (Gd3+-DTPA) release and redox-sensitive manganese oxide (MnO2) nanoparticles as a demonstration of generality, this method successfully evaluates the T1 shortening of water protons caused by liposomal Gd3+-DTPA release and Mn2+ formation from MnO2 reduction. Furthermore, the NMR measurement is highly correlated to T1-weighted MRI scans, suggesting its feasibility to predict the MRI results at the same field strength. This NMR method can be a low-cost, time-saving alternative for pre-MRI evaluation for a diversity of responsive T1 contrast systems.

Predicting the Electrical Conductivity of Partially Saturated Frozen Porous Media, a Fractal Model for Wide Ranges of Temperature and Salinity

AbstractThe quantitative determination of liquid water content and salinity in soils is crucial for the preservation of hydrological environments and engineering infrastructures, especially in frozen regions. Electrical conductivity, as a fundamental physical parameter in electrical and electromagnetic non‐destructive techniques, varies significantly with the physical and chemical properties, such as pore water conductivity, salinity, water saturation, and temperature. In this study, accounting for pore size and tortuous length following fractal distributions, we develop a new capillary bundle model for variation of electrical conductivity as a function of temperature in broad water saturation and salinity ranges. In this new model, we consider the contributions of bulk and surface conductivities to the total electrical conductivity. To test this model, a series of laboratory experiments were carried out for different initial water saturations and salinities using an electrical resistance apparatus and a nuclear magnetic resonance method. The experimental results show that unfrozen water saturation and ionic concentration affect the electrical conductivity of unsaturated frozen soils. Furthermore, the proposed model is capable of fitting the main trends of the experimental data from the literature and acquired in this study in unfrozen‐frozen conditions for different water contents. Relying on the proposed model, we also determine the expression of the apparent formation factor, which is significantly sensitive to porosity, water saturation, and temperature. The predicted values of the apparent formation factor also agree very well with the experimental data. This new capillary bundle model provides a new perspective in interpreting electrical monitoring to easily deduce changes in key variables in the cryosphere such as liquid water content and moisture gradients.

Features of a Low-Temperature Charge Density Wave in the Monoclinic Phase of NbS3 Manifested in the NMR and in Transport Properties

The relaxation of the transverse nuclear magnetization in the monoclinic phase of NbS3 has been studied by the 93Nb nuclear magnetic resonance method near the temperature TP2 = 150 K, at which a low-temperature charge density wave is formed. It has been shown that the critical slowing down of one of the vibrational modes of the lattice, which is quite slow even above TP2, occurs slightly below TP2. The transition at TP2 occurs not only in low-resistance samples, as thought previously, but also in high-resistance ones, and involves Nb atoms in the bulk of a sample. The transport properties of high-resistance samples, namely, the smearing of the depinning threshold for the charge density wave below TP2, confirm that the phase transition in them occurs at TP2. It has been concluded that the distortion of the lattice at TP2 is not due to the Peierls mechanism and can be attributed to the Keldysh–Kopaev transition. Another possible mechanism is the fluctuation distortion of the lattice above TP2 that prevents the sliding of the charge density wave.

Selective Detection of Intermediate-Amplitude Motion by Solid-State NMR.

The coexistence of rigid and mobile molecules or molecular segments abounds in biomolecular assemblies. Examples include the carbohydrate-rich cell walls of plants and intrinsically disordered proteins that contain rigid β-sheet cores. In solid-state nuclear magnetic resonance (NMR) spectroscopy, dipolar polarization transfer experiments are well suited for detecting rigid components, whereas scalar-coupling experiments are well suited for detecting highly mobile components. However, few NMR methods are available to detect the segments that undergo intermediate-amplitude fast motion. Here, we introduce two NMR experiments, a two-dimensional T2H-filtered CP-hCH correlation and a three-dimensional J-INADEQUATE CCH correlation, to observe this intermediate-amplitude motion. Both experiments involve 1H detection under fast magic-angle spinning (MAS). By combining 1H transverse relaxation (T2H) filters with dipolar polarization transfer, we suppress the signals of both highly rigid and highly mobile species, thus revealing the signals of intermediate mobile species. 1H detection under fast MAS is crucial for distinguishing the different motional amplitudes. We demonstrate these techniques on several plant cell wall samples and show that they allow the selective detection and resolution of certain hemicellulose and pectin signals, which are usually masked by the signals of the rigid cellulose and the highly dynamic pectins in purely dipolar and scalar NMR spectra.

The setting and hardening of geopolymer concrete based on low-field nuclear magnetic resonance and cyclic voltammetry methods

The hydration process has an important influence on the various properties of geopolymer concrete. However, current testing methods for hydration degree are complex and inconvenient, which limits the wide application of geopolymer concrete. For this reason, this study innovatively proposes new methods for non-destructive characterisation of the hydration degree based on low-field nuclear magnetic resonance and cyclic voltammetry techniques. Meanwhile, the setting and hardening characteristics of red mud-coal metakaolin geopolymer concrete with water-binder (W/B) ratios of 0.50, 0.55, 0.60 and 0.65, respectively, was systematically and comprehensively evaluated. The reaction mechanism of geopolymer concrete was revealed using a variety of testing methods such as SEM-EDS, thermogravimetric, and heat of hydration. The results show that the degree of hydration is significantly correlated with the intensity-weighted relaxation time and specific capacitance value, which can be expressed by pertinent equations. In addition, it is found that the hydration process of geopolymer concrete is divided into different stages, forming two gel phases, C-A-S-H and N-A-S-H. Increasing the W/B ratio promotes the generation of C-A-S-H gels but severely hinders the generation of N-A-S-H gels, overall adversely affecting the hydration process. This work will facilitate non-destructive monitoring of the status of geopolymer concrete during actual projects to ensure construction safety.

Studies of the Physical Structure of Cured Epoxy Resin Composite Modified with Silicon-Containing Additives

Abstract The possibility of regulating the structure and reducing its defectiveness opens great possibilities for controlling the properties of epoxy composite materials. This article reports the results of investigation by X-ray scattering and nuclear magnetic resonance methods and the microstructural changes that occur when silicon-containing additives such as polydimethyl siloxane (PDMS-5) and pyrogenic silica (HDK) are introduced into epoxy resin ED-20. The mechanism of formation of the structure of epoxy binder ED-20 with L-20 curing agent in the presence of complex additives is found. The modifying additive (PDMS-5 + HDK) is located in the epoxy binder because of the chemical interaction of functional polar groups and the developed surface. The additives increase the mobility of the reaction mixture and also facilitate and regulate the spatial orientation of macromolecules during polymerization. This contributes to the formation of a more regular and less defective spatial structure. The epoxy binder is a heterogeneous two-component system, one of which corresponds to a pseudo-crystalline region in which the movement of molecules is suppressed, and the second is found at lower volume fractions and is amorphous. The only maximum in the wide-angle X-ray diffraction pattern of the binder without additives is attributable to the distribution of molecular chains in the para-crystalline lattice. The addition of the HDK additive leads to ordering of the supramolecular structure, in which linear clusters consisting of 5–7 spheres appear. The average size of the spheres is from 8 to 26 nm. The addition of additives in the samples leads to the formation of a more regular and less defective spatial structure because of the interaction of functional polar groups and the surface, which regulate the spatial orientation of macromolecules during polymerization.

Exploring the Higher Order Structure and Conformational Transitions in Insulin Microcrystalline Biopharmaceuticals by Proton-Detected Solid-State Nuclear Magnetic Resonance at Natural Abundance.

The integrity of a higher order structure (HOS) is an essential requirement to ensure the efficacy, stability, and safety of protein therapeutics. Solution-state nuclear magnetic resonance (NMR) occupies a unique niche as one of the most promising methods to access atomic-level structural information on soluble biopharmaceutical formulations. Another major class of drugs is poorly soluble, such as microcrystalline suspensions, which poses significant challenges for the characterization of the active ingredient in its native state. Here, we have demonstrated a solid-state NMR method for HOS characterization of biopharmaceutical suspensions employing a selective excitation scheme under fast magic angle spinning (MAS). The applicability of the method is shown on commercial insulin suspensions at natural isotopic abundance. Selective excitation aided with proton detection and non-uniform sampling (NUS) provides improved sensitivity and resolution. The enhanced resolution enabled us to demonstrate the first experimental evidence of a phenol-escaping pathway in insulin, leading to conformational transitions to different hexameric states. This approach has the potential to serve as a valuable means for meticulously examining microcrystalline biopharmaceutical suspensions, which was previously not attainable in their native formulation states and can be seamlessly extended to other classes of biopharmaceuticals such as mAbs and other microcrystalline proteins.

Unraveling Molecular Recognition of Glycan Ligands by Siglec-9 via NMR Spectroscopy and Molecular Dynamics Modeling.

Human sialic-acid-binding immunoglobulin-like lectin-9 (Siglec-9) is a glycoimmune checkpoint receptor expressed on several immune cells. Binding of Siglec-9 to sialic acid containing glycans (sialoglycans) is well documented to modulate its functions as an inhibitory receptor. Here, we first assigned the amino acid backbone of the Siglec-9 V-set domain (Siglec-9d1), using well-established triple resonance three-dimensional nuclear magnetic resonance (NMR) methods. Then, we combined solution NMR and molecular dynamic simulation methods to decipher the molecular details of the interaction of Siglec-9 with the natural ligands α2,3 and α2,6 sialyl lactosamines (SLN), sialyl Lewis X (sLeX), and 6-O sulfated sLeX and with two synthetically modified sialoglycans that bind with high affinity. As expected, Neu5Ac is accommodated between the F and G β-strands at the canonical sialic acid binding site. Addition of a heteroaromatic scaffold 9N-5-(2-methylthiazol-4-yl)thiophene sulfonamide (MTTS) at the C9 position of Neu5Ac generates new interactions with the hydrophobic residues located at the G-G' loop and the N-terminal region of Siglec-9. Similarly, the addition of the aromatic substituent (5-N-(1-benzhydryl-1H-1,2,3-triazol-4-yl)methyl (BTC)) at the C5 position of Neu5Ac stabilizes the conformation of the long and flexible B'-C loop present in Siglec-9. These results expose the underlying mechanism responsible for the enhanced affinity and specificity for Siglec-9 for these two modified sialoglycans and sheds light on the rational design of the next generation of modified sialoglycans targeting Siglec-9.

Probing Molecular Packing of Lipid Nanoparticles from 31P Solution and Solid-State NMR.

Lipid nanoparticles (LNPs) are intricate multicomponent systems widely recognized for their efficient delivery of oligonucleotide cargo to host cells. Gaining insights into the molecular properties of LNPs is crucial for their effective design and characterization. However, analysis of their internal structure at the molecular level presents a significant challenge. This study introduces 31P nuclear magnetic resonance (NMR) methods to acquire structural and dynamic information about the phospholipid envelope of LNPs. Specifically, we demonstrate that the 31P chemical shift anisotropy (CSA) parameters serve as a sensitive indicator of the molecular assembly of distearoylphosphatidylcholine (DSPC) lipids within the particles. An analytical protocol for measuring 31P CSA is developed, which can be implemented using either solution NMR or solid-state NMR, offering wide accessibility and adaptability. The capability of this method is demonstrated using both model DSPC liposomes and real-world pharmaceutical LNP formulations. Furthermore, our method can be employed to investigate the impact of formulation processes and composition on the assembly of specifically LNP particles or, more generally, phospholipid-based delivery systems. This makes it an indispensable tool for evaluating critical pharmaceutical properties such as structural homogeneity, batch-to-batch reproducibility, and the stability of the particles.

Macroscopic and microscopic analysis of the effects of moisture content and dry density on the strength of loess.

To clarify the impact of moisture content and dry density on the strength of loess, the remolded loess samples with different moisture content and dry density were prepared, and the influence of moisture content and dry density on loess strength was explored from the macro level by direct shear test without suction control. On this basis, the mechanism of the influence of moisture content and dry density on loess strength was explored from the micro level by nuclear magnetic resonance method. The research results indicate that: In the case of low water content, there are peak points in the stress-strain curve of remolded loess, exhibiting strain softening characteristics. In the case of high water content, there is no obvious peak in the stress-strain curve, exhibiting strain hardening characteristics. Moisture has a significant impact on the shear strength of remolded loess. As the moisture content of the soil sample increases, the cohesion decreases significantly, and the change in internal friction angle is not obvious. As the moisture content continues to increase, the free water content continues to increase. Free water will continuously soften the soil particle structure, reduce the bonding force between soil particles, and cause the cohesion to decrease with the increase of moisture content. The change in dry density also has a significant impact on the shear strength parameters of remolded loess. As the dry density of the soil sample increases, the cohesion increases. The smaller the dry density, the larger the pore ratio, and the looser the contact between soil particles, weakening the bonding effect. The larger the pore ratio, the more bound water is converted to free water, and the strong bonding force between the water film and soil particles disappears. Both of these microscopic factors can lead to a decrease in cohesion with a decrease in dry density.

Determination of application boundaries to Giulotto method to during measuring of longitudinal relaxation time in nuclear magnetic flowmeters-relaxometers

The method of nuclear magnetic resonance, which is currently the most common in research and control of parameters of condensed matter, and the nuclear magnetic flowmeters-relaxometers that implement this method are described. The features of determining the times of longitudinal and transverse relaxation in nuclear magnetic flowmeters-relaxometers under different flow regimes of the medium in the process of monitoring its parameters have been established. The advantages of using a modulation technique for recording nuclear magnetic signals in flowmeters-relaxometers in comparison with other registration methods are noted. Using various approximations by the Giulotto method from the Bloch equations, a relation was obtained to determine the longitudinal relaxation time from the results of two measurements of the amplitudes of the nuclear magnetic resonance signal or resonant frequencies at different modulation frequencies. It has been experimentally proven that this relationship has a number of restrictions on its application for flowing liquid. These limitations are associated both with the technique of recording nuclear magnetic resonance signals and with the ability to generate such signals at different modulation frequencies of a constant magnetic field, the amplitudes of which differ from each other beyond the measurement error. The reasons that led to this discrepancy in the ratio for determining the time of longitudinal relaxation have been established. The limits of applicability of the obtained relation are found and it is experimentally proven that within these limits this relation can be used for reliable measurements of relaxation constants. Using experimental data, the relationship for determining the longitudinal relaxation time was studied. It has been proven that in a number of cases it is impossible to determine the desired value using the indicated relationship, although nuclear magnetic resonance signals of the current medium are recorded, and the medium has relaxation times. The results obtained make it possible to eliminate errors when using the nuclear magnetic resonance method to study flowing media and solve a number of complex problems in the energy, oil, chemical and pharmaceutical industries.

Metabolomic profiling of human bladder tissue extracts.

Bladder cancer is a common malignancy affecting the urinary tract and effective biomarkers and for which monitoring therapeutic interventions have yet to be identified. Major aim of this work was to perform metabolomic profiling of human bladder cancer and adjacent normal tissue and to evaluate cancer biomarkers. This study utilized nuclear magnetic resonance (NMR) and high-resolution nanoparticle-based laser desorption/ionization mass spectrometry (LDI-MS) methods to investigate polar metabolite profiles in tissue samples from 99 bladder cancer patients. Through NMR spectroscopy, six tissue metabolites were identified and quantified as potential indicators of bladder cancer, while LDI-MS allowed detection of 34 compounds which distinguished cancer tissue samples from adjacent normal tissue. Thirteen characteristic tissue metabolites were also found to differentiate bladder cancer tumor grades and thirteen metabolites were correlated with tumor stages. Receiver-operating characteristics analysis showed high predictive power for all three types of metabolomics data, with area under the curve (AUC) values greater than 0.853. To date, this is the first study in which bladder human normal tissues adjacent to cancerous tissues are analyzed using both NMR and MS method. These findings suggest that the metabolite markers identified in this study may be useful for the detection and monitoring of bladder cancer stages and grades.

11B NMR of the Morphological Evolution of Traditional Chinese Medicine Borax.

This article applies nuclear magnetic resonance technology to the study of boron-containing traditional Chinese medicine, in order to explore the morphological evolution of boron elements in traditional Chinese medicine. Borax is a traditional Chinese medicine with anti-corrosion, anti-inflammatory, antibacterial, and anticonvulsant effects. It is made by boiling, removing stones, and drying borax minerals like borate salts. This article introduces an 11B nuclear magnetic resonance method for identifying and characterizing boron-containing compounds in TCM. We applied this technology to borax aqueous solutions in different chemical environments and found that with boron mixed in the form of SP2 hybridization in equilateral triangles and SP3 hybridization in equilateral tetrahedra, the pH changes in alkaline environments significantly affected the ratio of the two. At the same time, it was found that in addition to the raw material peak, boron signals of other boron-containing compounds were also detected in 20 commercially available boron-containing TCM preparations. These new boron-containing compounds may be true pharmaceutical active ingredients, and adding them directly to the formula can improve quality and safety. This article describes the detection of 11B NMR in boron-containing traditional Chinese medicine preparations. It is simple, non-destructive, and can provide chemical fingerprint studies for boron-containing traditional Chinese medicine.