Spatiotemporal variations and influencing factors of methane emissions from livestock in China: A spatial econometric analysis.

In recent years, China has been implementing policies to improve the livestock industry in response to the global trend toward green and low-carbon development. These policies include the establishment of demonstration zones for high-standard agriculture, the relocation of farms to the north, etc. This study aims to investigate the impact of changes in the spatial structure of the livestock industry on methane emissions. It used panel data from 31 provinces in China from 2001 to 2021 and applied the IPCC methodology to quantify methane emissions at both the national and provincial levels. In addition, a spatial econometric model was used to analyze the impact of changes in the spatial structure of the livestock industry on methane emissions. The results show that methane from livestock in China decreased from 13.85 million tons in 2001 to 11.82 million tons in 2021. In addition, methane emissions from livestock in China show a significant spatial gradient and correlation. The Southwest has the highest methane emissions, accounting for 24 % of the total emissions. After controlling for spatial correlation and other factors in the model, it was found that the spatial structure of the livestock industry has a different influence on methane emissions both in the province and in neighboring provinces. To improve methane emission efficiency in the future, policies such as establishing functional zones for livestock farming, strengthening technological innovation and sharing for green development in agriculture, and promoting the optimization of agricultural and rural management structures should be implemented.

Antibacterial activity of lysozyme after association with carboxymethyl konjac glucomannan.

The unique high isoelectric point of lysozyme (LYZ) restricts its application in composite antibacterial coating due to the unfavorable liability to electrostatic interaction with other components. In this work, the antibacterial activity of a dispersible LYZ-carboxymethyl konjac glucomannan (CMKGM) polyelectrolyte complex was evaluated. Kinetic analysis revealed that, compared with free LYZ, the complexed enzyme exhibited decreased affinity (Km) but markedly increased Vmax against Micrococcus lysodeikticus, and QCM and dynamic light scattering analysis confirmed that the complex could bind with the substrate but in a much lower ratio. The complexation with CMKGM did not alter the antibacterial spectrum of LYZ, and the complex exerted antibacterial function by delaying the logarithmic growth phase and impairing the cell integrity of Staphylococcus aureus. Since the LYZ-CMKGM complex is dispersible in water and could be assembled easily, it has great potential as an edible coating in food preservation.

A trapped covalent intermediate as a key catalytic element in the hydrolysis of a GH3 ß-glucosidase: An X-ray crystallographic and biochemical study.

Glycoside hydrolases (GHs) are industrially important enzymes that hydrolyze glycosidic bonds in glycoconjugates. In this study, we found a GH3 ß-glucosidase (CcBgl3B) from Cellulosimicrobium cellulans sp. 21 was able to selectively hydrolyze the ß-1,6-glucosidic bond linked glucose of ginsenosides. X-ray crystallographic studies of the ligand complex ginsenoside-specific ß-glucosidase provided a novel finding that support the catalytic mechanism of GH3. The substrate was clearly identified within the catalytic center of wild-type CcBgl3B, revealing that the C1 atom of the glucose was covalently bound to the Oδ1 group of the conserved catalytic nucleophile Asp264 as an enzyme-glycosyl intermediate. The glycosylated Asp264 could be identified by mass spectrometry. Through site-directed mutagenesis studies with Asp264, it was found that the covalent intermediate state formed by Asp264 and the substrate was critical for catalysis. In addition, Glu525 variants (E525A, E525Q and E525D) showed no or marginal activity against pNPßGlc; thus, this residue could supply a proton for the reaction. Overall, our study provides an insight into the catalytic mechanism of the GH3 enzyme CcBgl3B.

Short-stranded DNA segment-modulated LAMP/H+ as signal transducer to guide CHA-cooperated amplifiable electrochemical biosensing.

BACKGROUND: Modulating loop-mediated isothermal amplification (mLAMP) by short-stranded DNA segment trigger (T) to generate byproducts H+ ions (mLAMP/H+) as signal transducer is intriguing for developing catalytic hairpin assembly (CHA)-cooperated amplifiable electrochemical biosensors. This would be a big challenge for traditional LAMP that is basically suitable for amplifying long-stranded oligonucleotides up to 200-300 nt. To address this inherent limitation of traditional LAMP, many researchers have put in efforts to explore improvements in this that would allow LAMP to be used for a wider range of target species amplification. RESULTS: Here in this work, we are inspired to explore two-step loop-mediated amplification, firstly forming T-activated double-loop dumbbell structure (DLDS) intermediate by a recognition hairpin and a hairpin precursor, and next DLDS-guided mLAMP process with the aid of two primers to yield mLAMP/H+ during successive DNA incorporation via nucleophilic attacking interaction. To manipulate the mLAMP/H+-directed transduction of input T, a pH-responsive triplex strand is designed with the ability of self-folding in Hoogsteen structure at slightly acidic conditions, resulting in the dehybridization of a fuel strand (FS) to participate in CHA between two hairpins on the modified electrode surface, in which FS is repetitively displaced and recycled to fuel the progressive CHA events. In the as-assembled dsDNA complexes, numerous electroactive ferrocene labels are immobilized in the electrode sensing interface, thereby generating significantly amplified electrochemical current signal that can sense the presented and varied T. SIGNIFICANCE: It is clear that we have creatively constructed a unique electrochemical biosensor for disease detection. Benefited from the rational combination of mLAMP and CHA, our electrochemical strategy is highly sensitive, specific and simplified, and would provide a new paradigm to construct various mLAMP/H+-based biosensors for other short-stranded DNA or microRNAs markers.

Integrating transcriptome and physiological analyses to elucidate the molecular responses of sorghum to fluxofenim and metolachlor herbicide.

The extensive use of herbicides has raised concerns about crop damage, necessitating the development of effective herbicide safeners. Fluxofenim has emerged as a promising herbicide safener; however, it's underlying mechanism remains unclear. Here, we screened two inbred lines 407B and HYZ to investigate the detoxication of fluxofenim in mitigating metolachlor damage in sorghum. Metolachlor inhibited seedling growth in both 407B and HYZ, while, fluxofenim could significantly restore the growth of 407B, but not effectively complement the growth of HYZ. Fluxofenim significantly increased the activities of glutathione-S-transferase (GST) to decrease metolachlor residue in 407B, but not in HYZ. This implys that fluxofenim may reduce metolachlor toxicity by regulating its metabolism. Furthermore, metolachlor suppressed AUX-related and JA-related genes expression, while up-regulated the expression of SA-related genes. Fluxofenim also restored the expression of AUX-related and JA-related genes inhibited by metolachlor and further increased expression of SA-related genes. Moreover, we noted a significant increase in the content of trans-zeatin O-glucoside (tZOG) and Gibberellin1 (GA1) after the fluxofenim treatment. In conclusion, fluxofenim may reduce the injury of herbicide by affecting herbicide metabolism and regulating hormone signaling pathway.

Global profiling of the proteome, phosphoproteome, and N-glycoproteome of protoscoleces and adult worms of Echinococcus granulosus.

Introduction: Cystic echinococcosis (CE) is a chronic zoonosis caused by infection with the metacestode of the Echinococcus granulosus. A unique characteristic of E. granulosus protoscolex (PSC) is their ability to develop bidirectionally into an adult worm in the definitive host or a secondary hydatid cyst in the intermediate host. Furthermore, cestodes have a complex life cycle involving different developmental stages; however, the mechanisms underlying this development remain unknown. Several studies have demonstrated that certain matrix proteins undergo posttranslational modifications (PTMs), including phosphorylation and glycosylation, which have important regulatory effects on their functional properties. Methods: Systematic analyses of the proteome, phosphorylated modified proteome, and glycosylated modified proteome of protoscoleces (PSCs) and adult worms were performed using a proteomic strategy. Data are available via ProteomeXchange with identifier PXD043166. Results: In total, 6,407 phosphorylation sites and 1757 proteins were quantified. Of these, 2032 phosphorylation sites and 770 proteins were upregulated, and 2,993 phosphorylation sites and 1,217 proteins were downregulated in adult worms compared to PSCs. A total of 612 N-glycosylation sites were identified in the 392 N-glycoproteins. Of these, 355 N-glycosylation sites and 212 N-glycoproteins were quantified. Of these, 90 N-glycosylation sites and 64 N-glycoproteins were upregulated, and 171 N-glycosylation sites and 126 N-glycoproteins were downregulated in adult worms compared to PSCs. GO enrichment analysis indicated that the differentially expressed phosphoproteins were mainly enriched in the regulation of oxidoreduction coenzyme metabolic processes, myelin sheath, and RNA helicase activity, whereas the differentially expressed N-glycoproteins were enriched in the cellular response to unfolded proteins, endoplasmic reticulum lumen, and nucleic acid binding. KEGG enrichment analysis indicated that the differently expressed phosphoproteins were mainly enriched in RNA transport, hypertrophic cardiomyopathy (HCM), glycolysis/gluconeogenesis, HIF-1 signaling pathway and pyruvate metabolism. Differentially expressed N-glycoproteins were enriched in the PI3K-Akt signaling pathway, ECM-receptor interactions, and protein processing in the endoplasmic reticulum. Discussion: To our knowledge, this study is the first global phosphoproteomic and N-glycoproteomic analysis of E. granulosus, which provides valuable information on the expression characteristics of E. granulosus and provides a new perspective to elucidate the role of protein phosphorylation and N-glycosylation in the development of E. granulosus.

Genome-Wide Identification and Analysis of the EPF Gene Family in Sorghum bicolor (L.) Moench.

The EPIDERMAL PATTERNING FACTOR (EPF) plays a crucial role in plant response to abiotic stress. While the EPF has been extensively studied in model plants such as Arabidopsis thaliana, there is a lack of research on identifying EPF genes in the whole sorghum genome and its response to drought stress. In this study, we employed bioinformatics tools to identify 12 EPF members in sorghum. Phylogenetic tree analysis revealed that SbEPFs can be categorized into four branches. Further examination of the gene structure and protein conservation motifs of EPF family members demonstrated the high conservation of the SbEPF sequence. The promoter region of SbEPFs was found to encompass cis-elements responsive to stress and plant hormones. Moreover, real-time fluorescence quantitative results indicated that the SbEPFs have a tissue-specific expression. Under drought stress treatment, most SbEPF members were significantly up-regulated, indicating their potential role in drought response. Our research findings establish a foundation for investigating the function of SbEPFs and offer candidate genes for stress-resistant breeding and enhanced production in sorghum.

Integration of transcriptome and metabolome analyses reveals sorghum roots responding to cadmium stress through regulation of the flavonoid biosynthesis pathway.

Cadmium (Cd) pollution is a serious threat to plant growth and human health. Although the mechanisms controlling the Cd response have been elucidated in other species, they remain unknown in Sorghum (Sorghum bicolor (L.) Moench), an important C4 cereal crop. Here, one-week-old sorghum seedlings were exposed to different concentrations (0, 10, 20, 50, 100, and 150 µM) of CdCl2 and the effects of these different concentrations on morphological responses were evaluated. Cd stress significantly decreased the activities of the enzymes peroxidase (POD), superoxide dismutase (SOD), glutathione S-transferase (GST) and catalase (CAT), and increased malondialdehyde (MDA) levels, leading to inhibition of plant height, decreases in lateral root density and plant biomass production. Based on these results, 10 µM Cd concentration was chosen for further transcription and metabolic analyses. A total of 2683 genes and 160 metabolites were found to have significant differential abundances between the control and Cd-treated groups. Multi-omics integrative analysis revealed that the flavonoid biosynthesis pathway plays a critical role in regulating Cd stress responses in sorghum. These results provide new insights into the mechanism underlying the response of sorghum to Cd.

Construction of Ni2P-MoC/Coal-Based Carbon Fiber Self-Supporting Catalysts for Enhanced Hydrogen Evolution.

Efficient and inexpensive electrocatalysts play an important role in the hydrogen evolution reaction (HER) of electrolytic water splitting. Herein, Ni2P-MoC/coal-based carbon fiber (Ni2P-MoC/C-CF) self-supporting catalysts were obtained by low-temperature phosphorization and high-temperature carbonization. The Mo source and oxidized coal were uniformly dispersed in the carbon support by electrospinning technology. A precursor of Ni was introduced by the impregnation method. The synergistic effect of MoC and Ni2P may reduce the strong hydrogen adsorption capacity of pure MoC and provide a fast hydrogen release process. In addition, the C-CFs prepared by electrospinning can not only prevent the agglomeration of MoC and Ni2P particles at a high temperature but also provide a self-supporting support for the catalyst. As a result, the catalytic performance of the HER was improved greatly, and a low overpotential of 112 mV at 10 mA cm-2 was exhibited stably by the Ni2P-MoC/C-CFs. This work not only converts coal into coal-based carbon materials but also provides a feasible pathway for the rational design of large-scale molded hydrogen electrocatalysts.

Effect of dietary soybean saponin Bb on the growth performance, intestinal nutrient absorption, morphology, microbiota, and immune response in juvenile Chinese soft-shelled turtle (Pelodiscus sinensis).

Soybean meal is widely applied in the aquafeeds due to the limitation of fish meal resources. Numerous studies have manifested that dietary soybean saponin, an anti-nutrient factor in soybean meal, may slow growth and induce intestinal inflammation in aquatic animals, but the possible causes are unclear. The juvenile Pelodiscus sinensis (mean initial body weight: 6.92 ± 0.03 g) were fed basal diet (CON group) and 2.46% soybean saponin Bb-supplemented diet (SAP group) for 35 days to further explore the effects of dietary soybean saponin Bb on the growth performance, apparent digestibility coefficients, intestinal morphology, the gut microbiota, intestinal transporters/channels, and immune-related gene expression. The results indicated that dietary soybean saponin Bb significantly decreased final body weight, specific growth rate, protein deposition ratio, and apparent digestibility coefficients (dry matter, crude protein, and crude lipid) of nutrients in Pelodiscus sinensis, which may be closely correlated with markedly atrophic villus height and increased lamina propria width in the small intestine. In addition, plasma contents of cholesterol, calcium, phosphorus, potassium, lysozyme, and C3 were significantly decreased in the SAP group compared with the control group. Soybean saponin Bb significantly downregulated the mRNA levels of glucose transporter 2, fatty acid binding protein 1 and fatty acid binding protein 2, amino acid transporter 2, b0,+-type amino acid transporter 1, and sodium-dependent phosphate transport protein 2b in the small intestine. At the same time, the expressions of key transcription factors (STAT1, TBX21, FOS), chemokines (CCL3), cytokines (TNF-α, IL-8), and aquaporins (AQP3, AQP6) in the inflammatory response were increased by soybean saponin Bb in the large intestine of a turtle. Additionally, dietary supplementation of SAP significantly reduced the generic abundance of beneficial bacteria (Lactobacillus, Bifidobacterium, and Bacillus) and harmful bacteria (Helicobacter and Bacteroides). In a nutshell, dietary supplementation of 2.46% soybean saponin not only hindered the growth performance by negatively affecting the macronutrients absorption in the small intestine but also induced an inflammatory response in the large intestine possibly by damaging the intestinal morphology, disturbing the intestinal microbiota and decreasing intestinal epithelial cell membrane permeability.

New stilbenoligan and flavonoid from the roots of Caragana stenophylla Pojark. and their anti-inflammatory activity.

A phytochemical investigation on the 80% ethanol extract of the roots of Caragana stenophylla Pojark. resulted in the isolation of 20 compounds, including two new ones, named kompasinol P (2) and 3,5,7,2',3'-pentahydroxy-4'-methoxyisoflavanone (3). Among them, a pair of enantiomers, (7S, 8 R, 7'R, 8'S)-kompasinol A (1a) and (7 R, 8S, 7'S, 8'R)-kompasinol A (1b), were successfully separated by the chiral-phase HPLC resolution for the first time. The absolute configurations of 1a and 1b were determined by the experimental and calculated electronic circular dichroism (ECD) data. 15 isolates were evaluated for their anti-inflammatory activity via inhibiting the production of nitric oxide (NO) in lipopolysaccharide (LPS)-stimulated murine macrophage RAW 264.7 cells. Compounds 1a/1b, 6, 7, 9, 10, 12, 14, and 16-18 showed moderate inhibition with IC50 values ranging from 11.45 to 68.54 µM.

Bioactive-guided isolation and identification of oligostilbenes as anti-rheumatoid arthritis constituents from the roots of Caragana stenophylla.

ETHNOPHARMACOLOGICAL RELEVANCE: The roots of Caragana stenophylla have been used as folk medicine due to the functions of activating blood, diuresis, analgesic and tonicity, especially in treating rheumatoid arthritis and hypertension. However, the anti-rheumatoid arthritis mechanisms and bioactive ingredients have not previously been fully investigated. AIM OF THE STUDY: The aim of this study was to assess the anti-rheumatoid arthritis effects of the roots of Caragana stenophylla ethanol extract (EC), elucidate its mechanism of action and identify its active substances. MATERIALS AND METHODS: Anti-rheumatoid arthritis activity of EC was assessed using type II-collagen induced arthritis in rats. Arthritis severity was evaluated by foot paw volume, arthritis index, joint swelling degree and histopathology. The serum inflammatory cytokines and matrix metalloproteinases (MMPs) were also detected by immunohistochemical analysis. In addition, the protein expression of IκB, p-IκB, iNOS and COX-2 was analyzed by western blot. RAW 264.7 macrophage cells were employed to assess the anti-inflammatory effects of fractions and compounds in vitro. UPLC-Q-TOF-MS was adopted to appraise the ingredients of the active fraction of the roots of C. stenophylla. Furthermore, various chromatographic techniques and spectroscopic methods were used for isolation and structure elucidation of compounds. RESULTS: The results showed that EC could reduce type II collagen-induced rheumatoid arthritis model arthritic score and histopathology markedly at dose of 240 mg/kg. Besides, EC could suppress the levels of pro-inflammatory cytokines (IL-1ß, IL-6, IL-8, IL-17, and TNF-α) and matrix metalloproteinases (MMP-3, MMP-9), and the expression levels of COX-2, p-IκB and iNOS also were declined. While, the levels of IL-10 and IκB were increased. The ethyl acetate fraction exhibited potent inhibitory effects against nitric oxide production in RAW 264.7 macrophage cells. Eleven main components including 1 flavonoid and 10 oligostilbenes from active fraction were isolated by mass directed chromatographic techniques. Their structures were determined on the basis of various spectroscopic methods and by comparison with the published NMR data. CONCLUSION: The roots of C. stenophylla attenuated arthritis severity, restored serum cytokine imbalances by regulating NF-κB signaling pathway in type II collagen-induced rheumatoid arthritis model. Oligostilbenes were essential ingredients in ethyl acetate extract of C. stenophylla roots. Stilbenes and flavonoids should be responsible for its anti-rheumatoid arthritis activities.

Correction for color artifacts using the RGB intersection and the weighted bilinear interpolation.

Due to the defects of optical systems, image sensors, and imperfect algorithms for image acquisition, compression, and restoration, color artifacts often appear in images obtained by imaging devices such as digital cameras and scanners. Moreover, color artifacts are difficult to eliminate because of technical limitations, even in some mature commercial cameras. On the basis of red, green, and blue (RGB) intersection (RGBI), a correction method for color artifacts is proposed in this paper, where the RGB intersection-based method can effectively detect various types of color artifacts. Also, by combining the object information with weighted bilinear interpolation, the continuity of the image is kept while restoring the real color. Experiments demonstrate that the RGBI method, which is applicable to all color images, can eliminate various types of color artifacts with accurate detection and less artifact residue, even if the image has severe color distortion or the areas of the color artifacts are small and discrete.

Monitoring algorithm of tilt angle based on sub-block plane fitting for high-resolution imaging.

The limitation of mechanical structure and misoperations can result in a small tilt angle formed by the sample and the focal plane, which will decrease the resolution of the imaging system. Moreover, the small tilt angle is difficult to be observed. In order to solve this problem, a monitoring algorithm of tilt angle based on sub-block plane fitting for high-resolution imaging systems has been proposed, which is used to measure the initial angle of most 2D samples before imaging and assist users to determine the tilt degree of the sample. Experiments demonstrate that the proposed method can measure the tilt angle with a high measurement precision of 0.007° and a low residual tilt angle of 0.004°, indicating that the algorithm has high measurement precision and stability. Further results show that the quality of the image will be improved by 20%-27% when the tilt angle is 0.3056°, which means that the small degree of tilt of the sample can seriously damage the image quality. Therefore, the study of tilt angle measurement has great significance for high-resolution imaging systems.

[Chemical constituents from roots of Caragana stenophylla and their anti-tumor activities].

Fourteen compounds were isolated from the 80% ethanol extract of Caragana stenophylla root, by using a combination of various chromatographic approaches, including silica gel sephadex LH-20 column chromatography, and preparative HPLC. On the basis of their physical and chemical properties and spectroscopic data, their structures were elucidated as 2-(4-hydroxy-3-methoxy lphenyl)-3-methoxyl benzofuran-6-ol (1), mucodianin C (2), isopterofuran (3), formononetin (4), afromosin (5), calycosin (6), acacetin (7), 3-O-methylkaempferol (8), liquiritigenin (9), isoliquiritigenin (10), variabilin (11), resveratrol (12), zhebeiresinol (13), and 2, 3-dicarboxy-6, 7-dihydroxy-1-(3', 4'-dihydroxy)-phenyl-1, 2-dihydronaphthalen (14). Compound 1 is a new benzofuran derivative, named as mucodianin S; compounds 2, 3, 11, 13, 14 were isolated from the genus Caragana for the first time, and compounds 4-10 were firstly isolated from Caragana stenophylla. MTT assay was used to determine their cytotoxicity of the isolated compounds against human tumor cell lines, and 2 showed cytotoxicity against human hepato cellular cancer (HepG2) and human cervical (HeLa) lines, with IC50 values of (16.18±0.95), (3.75±0.08) µmol•L ⁻¹, respectively.

Natural neuro-inflammatory inhibitors from Caragana turfanensis.

Because of the critical role of over-activated microglia in the progress of neurodegenerative diseases, it has been selected as a potential therapeutic target for drug discovery. In order to find natural neuroinflammatory inhibitors, we carried out a bioactivity-oriented phytochemical research of Caragana turfanensis Kom. (Krassn.), which is a folk medicine widely distributed in Xinjiang. As a result, a new coumarin lactone caraganolide A (1) and 35 known components were characterized from the effective extract of C. turfanensis. Furthermore, their anti-neuroinflammatory effects were evaluated in LPS-induced BV2 microglial cells using Griess assay to determine the release of nitric oxide (NO). Compounds 1, 2, 4-6, 9, 13-15, 20, 29 and 30 exhibited significant inhibitory activities and no obvious cytotoxicities were observed at their effective concentrations. It is noteworthy, the new compound caraganolide A (1) (IC50 1.01±1.57µM) and 3',7,8-trihydroxy-4'-methoxyisoflavone (5) (IC506.87±2.23µM) exhibited more excellent action than that of positive control minocycline (IC50 9.07±0.86µM).

Comprehensive chemical analysis of Schisandra chinensis by HPLC-DAD-MS combined with chemometrics.

The fruit of Schisandra chinensis, namely "Wuweizi" in China, is a well-known herbal medicine and health food. In this paper, an accurate and reliable high performance liquid chromatography coupled with diode array detection and mass spectrometry was developed for quality evaluation of Wuweizi. Nine lignans, including schisandrol A, schisandrol B, angeloylgomisin H, gomisin G, schisantherin A, schisanhenol, schisandrin A, schisandrin B, and schisandrin C were determined simultaneously in forty-three batches of Wuweizi samples collected from different localities. Thirty-six common peaks were unequivocally identified or tentatively assigned by comparing their mass spectrometric data with reference compounds, self-established compound library and published literatures. And the thirty-six common peaks were selected as characteristic peaks to assess the similarity of chromatographic fingerprinting of these Wuweizi samples. Moreover, hierarchical clustering analysis and principal components analysis were successfully applied to demonstrate the variability of these Wuweizi samples. The results indicated the content of nine investigated lignans varied greatly among the samples, and samples collected from different localities could be discriminated. Furthermore, schisandrol A, schisandrol B, schisandrin B, and schisandrin C were found to chemical marker for evaluating the quality of Wuweizi.

[Speciation analysis of harmful elements in Rhei Radix et Rhizoma, Chrysanthemi Flos].

OBJECTIVE: To investigate the state and distribution of Pb, Cd, Hg, As, Cu in Rhei Radix et Rhizoma and Chrysanthemi Flos. METHOD: The samples were prepared by modified Tessier sequential extraction; The elements of Cu, Pb, and Cd in the samples were analyzed by atomic absorption spectrometry (AAS), while Hg, and As were analyzed by atomic fluorescence (AFS). RESULT: Cu,Pb,Cd,Hg,As in Chrysanthemi Flos were 12.806, 10.478, 0.436, 0.231, 1.531 mg x kg(-1), respectively. Cu, Pb, Hg in Chrysanthemi Flos mainly existed in residual and organic states; Cd was priority to ion exchange state; the residual state was the main form of As, and ion exchange state and water soluble state also had a large proportion. Cu, Pb, Cd, Hg, As in Rhei Radix et Rhizoma were 10.530, 4.926, 0.478, 0.260, 0.750 mg x kg(-1), respectively. Cu, Pb and Hg of residual state were the highest ratio; Cd and As mainly existed in ion exchange state. CONCLUSION: The experiment results showed that sequential extraction can be applied in speciation analysis of the harmful elements of traditional Chinese medicine. The method can speciate the state and distribution of harmful elements and provide the information of harmful elements. It will provide reference to the production of Chinese traditional patent medicine and herb extracts, processing of medicine herbs, the development of new drugs and safety evaluation of traditional Chinese medicine.