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Objective: To establish a method for simultaneous determination of wogonoside, 4'-hydroxywogonin, norwogonin, baicalein, wogonin and chrysin in health care products by high performance liquid chromatography （HPLC）. Methods: The samples were extracted with acetone, C18 solid phase extraction column was used for purification. The target compounds were determined by HPLC, quantified by matrix-matched standard curve method. Phenomenex Luna®C18（250 mm×4.6 mm, 5 μm）column was applied, mobile phase was acctonitrile-acetic acid, using gradient elution）at the flow rate of 1.0 mL/min. The temperature of column was 30 ℃ and the detection wavelength was set at 280 nm. Results: The results showed that these 6 target compounds had good separation and the corresponding concentration had a good linear relationship with the peak area. Correlation coefficients （R2） were all greater than 0.99, RSDs of precision and stability tests were within 3.08% and the average recoveries were 83%~100% （RSD＜4.63%）. The limits of detection were 0.02~0.07 mg/kg. The limits of quantification were 0.08~0.25 mg/kg. Conclusion: This method is suitable for simultaneous determination of flavonoids in health care products with good reproducibility, and less consumption of organic solvents.

The classification and part segmentation of point cloud models are the basic tasks of 3D point cloud data processing, and the core is to obtain point cloud features that can effectively represent 3D models. This paper proposes a 3D point cloud feature learning network that introduces attention mechanisms. The network adopts a hierarchical point cloud feature extraction method. In the process of hierarchical feature extraction, the feature channel attention mechanism is adopted to obtain the correlation among channels, and the key channel information is enhanced. The spatial position attention mechanism is adopted to obtain the attention weight of each point based on the spatial information of the points. The enhanced point cloud feature is obtained by combining two or more attention mechanisms. Based on this feature, multi-level feature extraction is performed to obtain the final point cloud features for downstream tasks. Shape classification and part segmentation experiments are performed on Model- Net40 and ShapeNet datasets, respectively. The experimental results show that the proposed method can achieve high-precision and robust 3D point cloud shape classification and segmentation. [ABSTRACT FROM AUTHOR]

Micro layer of GO was obtained by micro adjustment and control. LiFePO4/graphene composite cathode materials were synthesized using a spray drying followed by high temperature reduction modification method, to improve conductivity of LiFePO4 with excellent conductivity of graphene. The structure, morphology and electrochemical performance of the composite materials were characterized by XRD, FTIR, SEM, TEM and electrochemical measurement technologies. The three-dimensional conductive network was constructed by graphene composite in material particles, which can improve the charge transfer rate of the interface of electrolyte/electrode materials and the electrochemical performance of LiFePO4. The results show that the discharge specific capacity of LiFePO4 without graphene is only 155mAh/g, while the discharge specific capacity of LiFePO4/graphene is 164mAh/g at 0.1C.The discharge specific capacity of LiFePO4/graphene is 140,119mAh/g at 1,2C,respectively.

The CNTs/rGO/NG composite lithiumion battery anode material was synthesized by thermal reducing, using graphene oxide (GO) and carbon nanotubes (CNTs) as precursors for a 5 ∶ 3 proportion. The morphology, structure, and electrochemical performance of the composite were characterized by scanning electron microscopy(SEM), X-ray diffractometry(XRD), Fourier transform infrared spectra (FTIR) and electrochemical measurements. The results show that reduced graphene oxide and carbon nanotubes form a perfect three-dimensional network structure on the surface of natural graphite. CNTs/rGO/NG composite has good rate performance and cycle life,compared with pure natural graphite.The initial discharge capacity of designed anode is 479mAh/g at 0.1C, the reversible capacity up to 473mAh/g after 100 cycles,the capacity is still 439.5mAh/g, the capacity retention rate is 92%,and the capacity is 457, 433, 394mAh/g at 0.5, 1, 5C, respectively.

The transformation of organoboron compounds plays an important role in synthetic chemistry, and recent advancements in boron-migration reactions have garnered considerable attention. Here, we report an unprecedented 1,2-boron migrative acylation upon photocatalysis-facilitated N -heterocyclic carbene catalysis. The design of a redox-active boronic ester substrate, serving as an excellent β-boron radical precursor, is the linchpin to the success of this chemistry. With the established protocol, a wide spectrum of β-boryl ketones has been rapidly synthesized, which could further undergo various C─B bond transformations to give multifunctionalized products. The robustness of this catalytic strategy is underscored by its successful application in late-stage modification of drug-derived molecules and natural products. Preliminary mechanistic investigations, including several control experiments, photochemistry measurements, and computational studies, shed light on the catalytic radical reaction mechanism.

Aim: To investigate the biological features of hepatitis B virus (HBV)-transfected HepG2.2.15 cells., Methods: The cell ultrastructure, cell cycle and apoptosis, and the abilities of proliferation and invasion of HBV-transfected HepG2.2.15 and the parent HepG2 cells were examined by electron microscopy, flow cytometry, 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and trans-well assay. Oncogenicity of the two cell lines was compared via subcutaneous injection and orthotopic injection or implantation in nude mice, and the pathological analysis of tumor formation was performed. Two cytoskeletal proteins were detected by Western blotting., Results: Compared with HepG2 cells, HepG2.2.15 cells showed organelle degeneration and filopodia disappearance under electron microscope. HepG2.2.15 cells proliferated and migrated slowly in vitro, and hardly formed tumor and lung metastasis in nude mice. Flow cytometry showed that the majority of HepG2.2.15 cells were arrested in G1 phase, and apoptosis was minor in both cell lines. Furthermore, the levels of cytoskeletal proteins F-actin and Ezrin were decreased in HepG2.2.15 cells., Conclusion: HepG2.2.15 cells demonstrated a lower proliferation and invasion ability than the HepG2 cells due to HBV transfection.