Previous studies have widely used surface electrogastrogram (EGG) signals to non-invasively evaluate gastric motility. However, it focused only on the assessment of electrical activity in a certain stomach region and lacked the analysis of interactions between different gastric regions. In the study, we aimed to assess the correlations of myoelectrical activity between distinct stomach areas using functional connectivity (FC) methods by three-channel EGG for the first time. The study contained 20 healthy subjects and the dataset for each subject consisted of two three-channel EGG signals (labeled as CH1, CH2 and CH3; CH1 projected onto the region of lesser curvature, CH3 projected onto the region of greater curvature, and CH2 positioned the region between CH1 and CH3) with a sampling rate of 2 Hz acquired from three locations of stomach during a 20-minute period of fasting and postprandial states respectively. Firstly, the EGG signals were band-pass filtered into three slow wave (SW) bands by finite impulse response (FIR) filter, namely bradygastria (0.017-0.033 Hz), normogastria (0.033-0.067 Hz) and tachygastria (0.067-0.15 Hz). Secondly, we employed four FC algorithms (i.e. Spearman correlation coefficient (SCC), phase lag index (PLI), mutual information (MI) and coherence (Coh)) to calculate the connection strength of each pair of gastric areas. Finally, the FC strength between fasting and postprandial conditions for all subjects or the normal weight (NW) or overweight (OW) people and between the NW and OW groups for both fasting and postprandial states were compared, respectively. The results indicated that compared to the fasting state, lower SCC of CH1 and CH3 in bradygastria for the NW group and significantly increased SCC of CH2 and CH3 in normogastria for all subjects were observed under the postprandial state. The NW group had greater MI of CH1-CH3 in bradygastria and normogastria during the fasting condition relative to the OW group. It was also found that the connections between CH1 and CH3 for Coh in normogastria and tachygastria and for MI in tachygastria and for SCC in normogastria were markedly increased in the normal individuals than those in the OW group under the postprandial state. Moreover, the connections of CH1-CH3 for SCC, MI in normogastria and for Coh in normogastria and tachygastria showed significantly negative correlations with body mass index during the postprandial condition. The findings of the study demonstrated that the FC techniques can be used as an exploratory analytical approach to assess gastric functional activity, and the FC strength in the NW group were remarkably increased in comparison with the OW group under the postprandial state, suggesting that it should be considered to separately analyze the EGG signals of individuals with normal weight and those who are overweight when conducting the gastric electrical analysis in scientific research or practical clinical practice.
Zhisen Wang, Sisi Guo, Jun Chen, Lu Wang, Huicong Zhang, Xiaocan Cui, Bingling Zhao, Shihui Ge, Sai Li, Mengliang Zhu, Peipei Xing
We aim to improve the quality control of Rhodiola rosea, Astragalus membranaceus, and Carthamus tinctorius capsules (RAC capsule) from the aspects of thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC), respectively, and the established quality control methods are suitable for their popularization and application in large-scale production. A TLC method was established for the identification of R. rosea, A. membranaceus, and C. tinctorius in RAC capsules. A HPLC method with gradient elution and UV detection was established for simultaneous determination of salidroside, tyrosol, hydroxysafflor yellow A (HSYA), anhydrosafflor yellow B (ASYB), and rhodiolin. The TLC chromatograms showed distinct and reproducible spots for the RAC capsule samples at positions consistent with those of the corresponding reference crude drugs, while no interfering spots were observed in the negative control samples. The HPLC method demonstrated excellent linearity (R 2 > 0.9991) for all five analytes within their respective concentration ranges with precision, stability, and repeatability; RSDs all below 2%; and average recoveries ranging from 95.07% to 105.61%. The developed TLC and HPLC methods are specific, accurate, and robust, providing a reliable quality control strategy for RAC capsules. The study supports the standardization of this herbal capsule formulation and establishes a foundation for further pharmacological research and clinical investigations.
Uncrystallized water (UCW) refers to the fraction of water in hydrated materials that remains uncrystallized upon cooling. Rather than forming bulk ice, this water retains molecular mobility even below the nominal freezing point. In polymers and proteins, UCW includes strongly bound water associated with specific functional groups and more weakly confined water residing in nanoscale environments. As a result, it plays an important role in mechanical behavior, structural stability, and biological function. Because UCW is heterogeneous, no single technique can fully capture its properties, and multiple complementary methods are required. This review highlights how dielectric spectroscopy (DS), nuclear magnetic resonance (NMR), differential scanning calorimetry (DSC), neutron scattering, particularly quasielastic neutron scattering (QENS), and terahertz and infrared spectroscopies each probe different aspects of UCW across distinct time and different sample sizes. We outline what each technique measures, the models commonly used to interpret the data, and how combining these approaches helps distinguish between “free,” “bound,” and “non-freezable” water. Studies that apply multiple methods to the same samples, with consistent control of hydration and temperature, are essential for developing a coherent and quantitative picture of UCW. This integrated approach is also key to translating UCW behavior into practical design principles for cryopreservation, pharmaceutical freezing, and biomaterials. Importantly, complementarity arises from differences in timescale and the distinct correlation functions each method probes. Computational spectroscopy–ranging from classical molecular dynamics to emerging machine learning approaches–provides an atomistic link between dielectric, NMR, neutron, and vibrational measurements and shared descriptors of hydration dynamics.
Mercuric ions (Hg 2+) are among the most hazardous heavy metal pollutants, posing severe threats to the human reproductive and central nervous systems even at trace concentrations. Although various fluorescent probes for Hg 2+ have been reported, most rely on a “turn-off” (fluorescence quenching) mechanism, which often suffers from low sensitivity and susceptibility to interference. Novel nitrogen-doped fluorescent carbon dots (FL-CDs) were synthesized for the first time via a one-pot hydrothermal method, using natural senna leaf as a green carbon source, and m-phenylenediamine as both the nitrogen dopant and functional monomer. This unique precursor combination endows the as-prepared FL-CDs with excellent optical properties. The obtained FL-CDs are spherical with an average size of 2.19 nm, exhibit bright green fluorescence at 518 nm, and possess a high quantum yield of 23.54%. Strikingly, in contrast to the common quenching effect of most heavy metal sensors, the fluorescence of FL-CDs was significantly enhanced upon Hg 2+ addition, achieving a desirable “turn-on” response. The probe exhibited exceptional selectivity toward Hg 2+ over other metal ions, with a detection limit of 10.65 μmol/L. This work not only introduces a new biomass precursor for the fabrication of carbon dots but also provides a simple, sensitive, and sustainable “turn-on” sensing platform for trace Hg 2+ detection. The proposed strategy offers a promising alternative for environmental monitoring and food safety analysis, and also contributes to the rational design of advanced functional materials derived from natural resources.
Nikita E. Harvey, Justine R. Bissonnette, Stacy Lambe, T. Nadine Burry, John G. Sled, John C. Kingdom, Ahmet A. Baschat, André J. Simpson, Lindsay S. Cahill, Karl J. Jobst
Micro- and nanoplastics (MNPs) are pervasive in the environment and are increasingly being detected in human tissues, including placenta, yet their effects on pregnancy outcome remain poorly understood. This study utilized pyrolysis gas chromatography x cyclic ion mobility mass spectrometry (Py-GCxcIMS) to overcome lipid interference and improve quantification of MNPs in human placentas from forty-six participants. Polyethylene (PE), polypropylene (PP), and polystyrene (PS) were targeted for analysis. MNPs were detected in 26% of placental tissue samples (24/92) and in 41% of participants (19/46), with total polymer concentrations ranging from 0.1 to 12.3 μg/g (mean total of 0.5 μg/g). The variability in microplastic concentrations across the different placental regions highlights the organ’s heterogeneous nature. Polypropylene was the most frequently detected, while polystyrene showed the highest mean concentration. Although no direct link to birth outcomes was found, the exploratory analysis suggested sex-specific association in complicated pregnancies (p = 0.071 for males) underscores the need for expanded cohort studies. These results provide evidence of MNP presence in human placental tissue, emphasizing the importance of larger human cohort studies and robust analytical methods to better understand the potential impact MNPs have on pregnancy and fetal health.
