Metabolic syndrome (MetS) has become a major public health challenge in recent years. Nuclear magnetic resonance, as a nondestructive measurement, has been widely used in medical diagnosis and screening. Compared to conventional magnetic resonance imaging and nuclear magnetic spectroscopy, low-field nuclear magnetic resonance is superior in portability, simplicity, and low-cost. In this study, a novel approach based on low-field magnetic resonance analysis is proposed to detect metabolic syndrome. T1–T2 correlation relaxometry is employed to measure human serum. Combining with a classification model based on partial least squares discriminant analysis (PLS-DA), the detection of metabolic syndrome is realized. The classification models based on both T1–T2 relaxation correlation data and spectrum are compared. Additionally, classification model based on convolutional neural networks (CNNs) is also evaluated for comparison. The experimental results indicate that the PLS-DA model based on the T1–T2 spectrum achieves a better performance. Specifically, the area under curve, accuracy, F1 score, recall and precision of the classification model evaluated on testing group are 0.784, 70.91%, 75.00%, 77.42%, and 72.73%, respectively. On the other hand, the testing results of CNN model trained using T1–T2 spectrum are 0.774, 65.45%, 61.22%, 48.39%, and 83.33% for AUC, accuracy, F1 score, recall, and precision. The experimental results reveal the limitation of CNN models on small datasets. In this study, T1–T2 correlation relaxometry is employed for the analysis of MetS for the first time, and the feasibility of proposed method has been demonstrated.

Quantum computational simulations based on density functional theory are employed to investigate the molecular structure of Retinol. Both geometrical parameters and electronic transitions for gas and green solvents are calculated. Characteristic frequencies were identified and band assignments were achieved through normal coordinate analysis. The calculated spectra and a comparative study of the vibrational spectra, which included a variety of vibration modes, were compared with the experimental spectra. A compound’s strong reactivity may be indicated by the bandgap, which also indicates the possibility of further charge exchange through the molecule. Determination of relative electrophilicity/nucleophilicity indices of retinol was undertaken through the prediction of condensed Fukui functions, complemented by the generation of molecular electrostatic potential surface maps. This exploration was validated through meticulous correlation with reduced density gradient and isodensity surface plots. The docking analysis of retinol with different proteins was performed to confirm anti-inflammatory activity. To gain comprehensive insights into macromolecule pliability concerning protein–ligand interactions, an effective molecular dynamics simulation was conducted.

Lotus root is a popular traditional Chinese food of great economic and nutritional significance, which has different qualities, characteristics, and commercial value from various regions due to the climate and growing environment. Therefore, it is essential and urgent to establish an accurate and effective method to trace the geographical origins of lotus roots. This study combined mineral element analysis and multivariate statistical analysis to discriminate the origins of 147 lotus root samples from different production regions of China. The concentrations of 15 elements were determined by inductively coupled plasma emission spectrometry and inductively coupled plasma mass spectrometry. In addition, chemometric techniques, including ANOVA, principal component analysis and stepwise linear discriminant analysis were utilized to identify the geographical origin of lotus roots. The results showed that the levels of the 15 elements were significantly different by ANOVA. The study indicates that stepwise linear discriminant analysis yielded an average discrimination rate of 99.3%.

The emergence of the integrated wavelength-dispersive and energy-dispersive Zetium X-ray fluorescence spectrometer technique offered new chances to analyze elemental distribution with minimal sample preparation in complex matrix geological samples-northern Hainan island soils. Wavelength-dispersive X-ray fluorescence was applied for the measurement of bromine in the northern Hainan island soil. To reduce the fluctuations of the low-bromine-content measurement results, a two-channel measurement of bromine was designed, and the average value of the two-channel measurements was used as the final result. The soil samples in northern Hainan Island were rich in iodine, with a content range of a few µg/g to more than 100 µg/g, and these were particularly suitable to be analyzed by energy-dispersive X-ray fluorescence spectrometer. The geological samples in northern Hainan Island were brown, purple, and brown-red soil containing kaolinite, ilmenite, rutile, anatase, and goethite. These soil samples were rich in titanium, aluminum, and iron. The titanium concentration in the northern Hainan Island soil was anomalously high (up to 15.05%), far exceeding the content range of the calibration curve. Owing to the empirical coefficient matrix correction method, unreliable or even unreasonable results were obtained for some elements. By systematically mitigating matrix effects through the development of custom reference materials and building matrix-matched measurement and calibration routines, the quantification of Vanadium, Barium, and major components in northern Hainan Island soil samples was optimized. The efficacy of the X-ray fluorescence spectrometer method was confirmed by comparison with inductively coupled plasma–optical emission spectroscopy analysis. This work demonstrates the capability of the integrated wavelength-dispersive and energy-dispersive Zetium X-ray fluorescence spectrometer technique for reliable quantitative elemental analysis of complex matrix geological samples.

Terahertz spectroscopic studies of 4-octyloxybenzoic acid, 4-decyloxybenzoic acid and 4-hexylbenzoic acid liquid crystals were performed using the Fourier Transform Infrared method. The materials are characterized by distinct absorption bands in the 6–18 terahertz frequency range. A good correspondence was observed between the experimental frequencies and theoretical frequencies of the single molecule obtained by Density Functional Theory calculations for all the three compounds. The spectra of the studied compounds had three bands, which appeared at similar frequencies and with the same vibration modes. 4-Octyloxybenzoic acid, 4-decyloxybenzoic acid and 4-hexylbenzoic acid had two absorption bands that appeared at similar frequencies and exhibited different vibration modes. This study interestingly demonstrates that even though compounds of an almost similar molecular structure might output bands at the same frequencies, the correspondence might not be apparent. The single molecule model frequencies and experimental frequencies for 4-decyloxybenzoic acid and 4-octyloxybenzoic acid further revealed that all the observed bands are due to intramolecular interaction. However, the 4-hexylbenzoic acid spectrum has one apparently intermolecular band. This work addresses the limitation in the intermediate terahertz spectroscopic studies of liquid crystals and furthermore emphasizes the robustness of Fourier Transform Infrared technique in identifying materials with similar attributes.

Taking adulterated milk as the research object, the principal component analysis method combined with long short-term memory network was used to study, aiming to find a simple and efficient rapid detection method for adulterated milk. In this paper, qualitative and quantitative analysis of adulterated milk was carried out based on near-infrared hyperspectral data (400–1000 nm). The experimental results verified the feasibility of using near-infrared hyperspectral technology to identify adulterated milk.

A new strategy for the determination of Cu(II) ions was developed using K10H3[Eu(SiMo6W5O39)2]·28H2O. The polyoxometalate H4SiMo6W6O40 acts as a ligand to sensitize the europium ion to emit red fluorescence, and the fluorescence was quenched by the addition of Cu(II) ions. The luminescence of the central Eu3+ was quenched due to the inner filter effect (IFE) of Cu(II) to K10H3[Eu(SiMo6W5O39)2]·28H2O and the static burst. Therefore, K10H3[Eu(SiMo6W5O39)2]·28H2O can be used as a specific fluorescent probe for Cu2+ and it exhibited a very good linear response range for copper ions from 1 to 20 μM with detection limit of 0.13 µM. The probe was successfully applied to the determination of Cu(II) ions in clam samples with recoveries in the range of 90–98%.

Plant extract mediated nanoparticles have gained enormous attention for their green and rational approach and developed as an alternative to conventional chemical and physical methods. Here, the less exploited Jatropha integerrima flower extract is used in the synthesis of silver nanoparticles. The as-prepared nanoparticles exhibit a strong surface plasma resonance around 420 nm. Several spectroscopic techniques confirmed the formation of silver nanoparticles with an average size of 32.07 nm, stabilized by functional groups. The catalytic activity of synthesized nanoparticles for Rhodamine B dye degradation in the presence of sodium borohydride was investigated. The results showed that the 100 µL catalyst dose degraded the alkaline solution of dye up to 98%, with a high rate constant of 1.2110 min−1. In addition, the nanoparticles were tested for antioxidant activity using the 2,2-dipehnyl-1-picrylhydrazyl free radical assay. The calculated IC50 value for synthesized nanoparticles was 33.63 ± 0.53 µg/mL. Thus, the as-prepared nanoparticles are excellent candidates for catalytic and antioxidant activities compared to other materials used so far.

Accurate chemical shift and coupling constant for 1- and 2-naphthyl derivatives were decipher by iterative full spin analysis. Each of the seven magnetically nonequivalent H2–H8 atoms in 1-naphthyl derivatives, or of the H1, H3–H8 atoms in 2-naphthyl derivatives were unambiguously identified by analyzing their intra- and inter-ring coupling constants at 300 MHz and by two-dimensional homo- and heteronuclear experiments at 750 MHz. 13C chemical shifts were also determined during this study, from where some literature ambiguities were resolved using long-range C–H correlations at 750 MHz. The complete proton nuclear magnetic resonance parameters are herein ascribed for the first time.

The level of applied microwave power is a critical parameter for the quality of the dried product in microwave drying. It is impossible to assess the applied power of the dried product with the naked eye. This work aimed to predict the applied power of black carrot powders using a chromameter and near-infrared reflectance spectroscopy with partial least squares regression. A good correlation was found between applied power, color parameters, and near-infrared reflectance. The near-infrared spectroscopy predicted the applied power with better performance (R 2 = 0.99) and can be utilized to appraise the applied power of black carrot powders with acceptable accuracy.