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Research on landslide hazard assessment in data‑deficient areas: a case study of Tumen City, China

Li Xia, Cheng Jiulong, Yu Dehao, Han Yangchun

Acta Geophysica

2023

Vol. 71, no. 4

1763--1774

With the development of economy, the urbanization process is accelerated and the infrastructure construction is increased, which leads to the widespread occurrence of landslides in mountain areas all over the world. However, due to the complex geological environment or some other reasons, the lack of landslide-related data in some mountainous areas makes it more difficult to predict landslides. At the same time, the existing models have different prediction effects in different regions, and it is difficult for a single model to objectively and accurately evaluate landslide hazard. The purpose of this research is to complete the landslide hazard assessment (LHA) in data-deficient areas by proposed a combination model with help of remote sensing (RS) and geographic information system (GIS) technology. Firstly, 146 landslides and 10 LHA conditioning factors in Tumen City were obtained by using RS, GIS and field investigation. To increase the amount of model training data, 386 landslides (including 146 landslides in Tumen City) in some areas of Yanbian Korean Autonomous Prefecture with similar landslide conditions to Tumen City were obtained. Secondly, three combination models for LHA are proposed, which make full use of the effective information provided by logistic regression (LR), artificial neural network (ANN) and support vector machine (SVM), and the evaluation effect and applicability of the three combination models are discussed. Finally, the three combination models and three single models of logistic regression (LR), artificial neural network (ANN), support vector machine (SVM) are analyzed and compared through the overall accuracy (OA), confusion matrix and landslide density. The results show that it can effectively complete the landslide hazard assessment in data-deficient areas with help of RS and GIS, and the three combination models proposed in this research are superior to the other three single models, and the evaluation effect of the LA-SVM combination model is the best.

An improved ultra-high performance liquid chromatography-tandem mass spectrometry method determining hispidulin and homoplantaginin in rat plasma and associated pharmacokinetic studies

Zhang En, Chen Junying, Li Xia, Luo Lvqi, Ma Yizhe, Zhang Qingwei, Wang Xianqin

Acta Chromatographica

2023

Vol. 35, no. 4

331--337

Flavonoids are the most abundant components in Salvia plebeia, with significant pharmacological antioxidant and hepatoprotective properties. Hispidulin and homoplantaginin are the main flavonoid components in S. Plebeia. In this study, we established an ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) to determine hispidulin and homoplantaginin in rat plasma samples, which were precipitated using acetonitrile-methanol (9:1, v/v). We used a UPLC HSS T3 (100 mm × 2.1 mm, 1.7 μm diameter) chromatographic column, an acetonitrile-water (containing 0.1% formic acid) mobile phase, and a gradient elution flow rate of 0.4 mL min⁻¹ in an elution time of 4 min. We used electrospray ionization (ESI) detection in positive ion mode, and multiple reaction monitoring mode (MRM) for quantitative analysis: m/z 301 → 286 for hispidulin, m/z 463 → 301 for homoplantaginin, and m/z 465 → 303 for internal standard (IS). In pharmacokinetic studies, 24 rats were orally administered hispidulin and homoplantaginin (5 mg kg⁻¹) and received sublingual intravenous injections (1 mg kg⁻¹) at two different doses, four groups with six rats/group. Differences in hispidulin and homoplantaginin pharmacokinetics in rat plasma were evaluated. The calibration curve showed good linearity in the 0.5–1,000 ng mL⁻¹ range, with r > 0.99. Precision, accuracy, recovery, matrix effects, and stability results all met standard biological sample detection requirements. Our pharmacokinetic studies showed hispidulin bioavailability was much higher than homoplantaginin at 17.8% and 0.1%, respectively.

Quality evaluation of commercial products of Ganoderma lucidum made from its fruiting body and spore

Yeung Steven, Chen Quanlan, Yu Yongbang, Zhou Bingsen, Wu Wei, Li Xia, Huang Ying, Wang Zhijun

Acta Chromatographica

2022

Vol. 34, no. 1

100--113

Ganoderma lucidum (GL), also known as Reishi or Lingzhi, is a medicinal mushroom widely used in traditional and folk medicines. The extracts made from the fruiting body and spore of naturally grown GL are the most frequently used in commercial products. More than 400 compounds have been identified in GL with the triterpenoids considered to be the major active components. Large variations in the chemical components were reported in previous studies and there is no comprehensive study of the content of multiple major triterpenoids in the GL product. In addition, there is no report in the comparison of chemical profiles in different parts of GL (i.e., fruiting body and spore). Determining the chemical composition and comparing the differences between fruiting body and spore are essential for the identity, efficacy and safety of various GL products. In this study, 13 compounds (ganoderenic Acid C, ganoderic Acid C2, ganoderic Acid G, ganoderic Acid B, ganoderenic Acid B, ganoderic Acid A, ganoderic Acid H, ganoderenic Acid D, ganoderic Acid D, ganoderic Acid F, ganoderic Acid DM, ganoderol A, and ergosterol) were selected as the chemical markers. The purpose of this study is to develop an HPLC-DAD fingerprint method for quantification of these active components in GL (spore and fruiting body) and test the feasibility of using the HPLC-DAD fingerprint for quality control or identity determination of GL products. The results showed that this method could determine the levels of the major components accurately and precisely. Among the 13 components, 11 ganoderma acids were identified to be proper chemical markers for quality control of GL products, while ganoderal A was in a very low amount and ergosterol was not a specific marker in GL. The extracts of fruiting body contained more chemical compounds than those of spore, indicating that these 11 compounds could be a better chemical marker for the fruiting body than the spore. The HPLC chemical fingerprint analysis showed higher variability in the quality of GL harvest in different years, while lesser variation in batches harvested in the same year. In conclusion, an HPLC assay detecting 11 major active components and a fingerprinting method was successfully established and validated to be feasible for quality control of most commercial GL products.