Identification of Panax notoginseng origin using terahertz precision spectroscopy and neural network algorithm.

Panax notoginseng (P. notoginseng), a Chinese herb containing various saponins, benefits immune system in medicines development, which from Wenshan (authentic cultivation) is often counterfeited by others for large demand and limited supply. Here, we proposed a method for identifying P. notoginseng origin combining terahertz (THz) precision spectroscopy and neural network. Based on the comparative analysis of four qualitative identification methods, we chose high-performance liquid chromatography (HPLC) and THz spectroscopy to detect 252 samples from five origins. After classifications using Convolutional Neural Networks (CNNs) model, we found that the performance of THz spectra was superior to that of HPLC. The underlying mechanism is that there are clear nonlinear relations among the THz spectra and the origins due to the wide spectra and multi-parameter characteristics, which makes the accuracy of five-classification origin identification up to 97.62%. This study realizes the rapid, non-destructive and accurate identification of P. notoginseng origin, providing a practical reference for herbal medicine.

Effect of Specimen Geometry on the Thermal Desorption Spectroscopy Evaluated by Two-Dimensional Diffusion-Trapping Coupled Model.

The hydrogen diffusion process in ferritic steel during thermal desorption tests was simulated using the finite element method based on the two-dimensional diffusion-trapping coupled model. This model was first verified by experimental data to obtain a physically meaningful combination of trap/lattice parameters. Then, the effect of specimen geometry was studied by varying the height of cylindrical specimens with other parameters fixed at constant values. Simulation of desorption spectra with different specimen geometries indicates that the measurement of hydrogen concentration is not affected by the change in specimen geometry due to the mass conservation law, for original thermal desorption spectra (TDS), which are, however, unlikely to be detected in traditional experiments due to the necessity of specimen transfer procedures. Considering the hydrogen escape during rest time (specimen preparation/transfer/evacuation), the measured TDS curves are expected to be strongly dependent on the specimen geometry. The effect of specimen geometry on desorption spectra is more pronounced for smaller specimens, resulting in the dramatic decrease in peak flux and the increased error of Kissinger method in the determination of trap deactivation energy. The present study may contribute to better understanding and more reliable interpretation of the TDS curves by considering the size effect.

Multiscale Statistical Analysis of Massive Corrosion Pits Based on Image Recognition of High Resolution and Large Field-of-View Images.

In the present study, a new multiscale method is proposed for the statistical analysis of spatial distribution of massive corrosion pits, based on the image recognition of high resolution and large field-of-view (montage) optical images. Pitting corrosion for high strength pipeline steel exposed to sodium chloride solution was observed using an optical microscope. Montage images of the corrosion pits were obtained, with a single image containing a large number of corrosion pits. The diameters and locations of all the pits were determined simultaneously using an image recognition algorithm, followed by statistical analysis of the two-dimensional spatial point pattern. The multiscale spatial distributions of pits were analyzed by dividing the montage image into a number of different windows. The results indicate the clear dependence of distribution features on the spatial scales. The proposed method can provide a better understanding of the pit growth from the perspective of multiscale spatial evolution.

[Role of epithelial sodium channel in rat osteoclast differentiation and bone resorption].

OBJECTIVE: To explore the role of epithelial sodium channel (ENaC) in regulating the functional activity of osteoclasts. METHODS: Multinucleated osteoclasts were obtained by inducing the differentiation of rat bone marrow cells with macrophage colony-stimulating factor (M-CSF) and RANKL. The osteoclasts were exposed to different concentrations of the ENaC inhibitor amiloride, and the expression of ENaC on osteoclasts was examined using immunofluorescence technique. The osteoclasts were identified with tartrate-resistant acid phosphatase (TRAP) staining, and the positive cells were incubated with fresh bovine femoral bone slices and the number of bone absorption pits was counted by computer-aided image processing. RT-PCR was performed to analyze the expression of cathepsin K in the osteoclasts. RESULTS: s Exposure to different concentrations of amiloride significantly inhibited the expression of ENaC and reduced the number of TRAP-positive osteoclasts. Exposure of the osteoclasts to amiloride also reduced the number of bone resorption pits on bone slices and the expression of osteoclast-specific gene cathepsin K. CONCLUSION: s ENaC may participate in the regulation of osteoclast differentiation and bone resorption, suggesting its role in functional regulation of the osteoclasts and a possibly new signaling pathway related with ENaC regulation for modulating bone metabolism.

[The role of apoptosis in herpes simplex virus I type myocarditis of mouse].

OBJECTIVE: To explore the relation among apoptosis of myocardial cell and the expression of TGF-beta1 in VMC. METHODS AND RESULTS: In the experiment, Viral myocarditis (VMC) in BALB/C mouse was obtained by inculating herpes simplex virus I type into abdominal cavity. The rate of VMC was 91.67% after 3 - 35 days of virus infection. The apoptosis (78.33%) and expression of TGF-beta1 (81.76%) were found in the myocardium of infected mouse by TUNEL and immunohistochemical method and electron microscope. AI of myocardial cell was 34.14+/-11.56 - 26.14+/-10.2. CONCLUSION: Apoptosis and expression of TGF-beta1 may participate in occurrence and development of VMC.