Farmland protection and fertilization intensity: Empirical evidence from preservation policy of Heilongjiang's black soil.

The preservation of cultivated land quality stands as a vital prerequisite for ensuring food security and sustainability. In the black soil area of northeast China, a large amount of fertilizer was used to stabilize grain production in its early stages, which damaged soil structure and polluted the ecological environment. Based on the panel data of fertilization intensity of 48 districts and counties in Heilongjiang Province from 2010 to 2020, this study takes the implementation of the "Three-Year Action Plan for the Protection of Black Soil Farmland in Heilongjiang Province for the (2018-2020)" (TYAP) policy as a natural experiment, and uses the difference-in-differences (DiD) method to identify the causal effect of the policy on the local fertilization intensity. The results of the empirical study showed that the implementation of the TYAP policy significantly reduced the fertilization intensity of the black soil cultivated land implemented by the policy during the implementation period, which resulted in a decrease of 11.97% on average compared with the areas without the policy implementation. Several robustness tests provided additional confirmation of the aforementioned findings. This study further revealed that the policy mitigated fertilization intensity by fostering advancements in agricultural mechanization.

The small GTPase NtRHO1 negatively regulates tobacco defense response to tobacco mosaic virus by interacting with NtWRKY50.

Small GTPases play critical roles in the regulation of plant growth and development. However, the mechanism of action of small GTPases in plant response to virus infection remains largely unknown. Here, the gene encoding a Rho-type GTPase, NtRHO1, was identified as one of the genes up-regulated after tobacco mosaic virus (TMV) infection. Subcellular localization of NtRHO1 showed that it was located in the cytoplasm, plasma membrane, and nucleus. Transient overexpression of NtRHO1 in Nicotiana benthamiana accelerated TMV reproduction and led to the production of reactive oxygen species. By contrast, silencing of NtRHO1 reduced the sensitivity of N. benthamiana to TMV-GFP. Further exploration revealed a direct interaction between NtRHO1 and NtWRKY50, a positive regulator of the N. benthamiana response to virus infection. Yeast one-hybrid and electrophoretic mobility shift assays showed that this regulation was related to the capacity of NtWRKY50 to bind to the WK-box of the PR1 promoter, which was weakened by the interaction between NtRHO1 and NtWRKY50. Thus, our results indicate that the small GTPase NtRHO1 plays a negative role in tobacco response to TMV infection by interacting with transcription factor NtWRKY50, resulting in reduced plant immunity.

SFA-MDEN: Semantic-Feature-Aided Monocular Depth Estimation Network Using Dual Branches.

Monocular depth estimation based on unsupervised learning has attracted great attention due to the rising demand for lightweight monocular vision sensors. Inspired by multi-task learning, semantic information has been used to improve the monocular depth estimation models. However, multi-task learning is still limited by multi-type annotations. As far as we know, there are scarcely any large public datasets that provide all the necessary information. Therefore, we propose a novel network architecture Semantic-Feature-Aided Monocular Depth Estimation Network (SFA-MDEN) to extract multi-resolution depth features and semantic features, which are merged and fed into the decoder, with the goal of predicting depth with the support of semantics. Instead of using loss functions to relate the semantics and depth, the fusion of feature maps for semantics and depth is employed to predict the monocular depth. Therefore, two accessible datasets with similar topics for depth estimation and semantic segmentation can meet the requirements of SFA-MDEN for training sets. We explored the performance of the proposed SFA-MDEN with experiments on different datasets, including KITTI, Make3D, and our own dataset BHDE-v1. The experimental results demonstrate that SFA-MDEN achieves competitive accuracy and generalization capacity compared to state-of-the-art methods.

Chilli veinal mottle virus HCPro interacts with catalase to facilitate virus infection in Nicotiana tabacum.

Plant symptoms are derived from specific interactions between virus and host components. However, little is known about viral or host factors that participate in the establishment of systemic necrosis. Here, we showed that helper component proteinase (HCPro), encoded by Chilli veinal mottle virus (ChiVMV), could directly interact with catalase 1 (CAT1) and catalase 3 (CAT3) in the cytoplasm of tobacco (Nicotiana tabacum) plants to facilitate viral infection. In vitro, the activities of CAT1 and CAT3 were inhibited by the interaction between HCPro and CATs. The C-terminus of HCPro was essential for their interaction and was also required for the decrease of enzyme activities. Interestingly, the mRNA and protein level of CATs were up-regulated in tobacco plants in response to ChiVMV infection. Nicotiana tabacum plants with HCPro overexpression or CAT1 knockout were more susceptible to ChiVMV infection, which was similar to the case of H2O2-pre-treated plants, and the overexpression of CAT1 inhibited ChiVMV accumulation. Also, neither CAT1 nor CAT3 could affect the RNA silencing suppression (RSS) activity of HCPro. Our results showed that the interaction between HCPro and CATs promoted the development of plant systemic necrosis, revealing a novel role for HCPro in virus infection and pathogenicity.

Astaxanthin protects cognitive function of vascular dementia.

OBJECTIVE: The purpose of this study was to evaluate the effect of astaxanthin (AST) on cognition function, inflammatory response and oxidative stress in vascular dementia (VD) mice. METHOD: VD mice model was established by left unilateral common carotid arteries occlusion (LUCCAO). Following LUCCAO, AST was intragastrically administered for 30 days. Object recognition test and morris water maze test were used to evaluate cognitive function. Hematoxylin and eosin staining was performed to observe the hippocampal neuron structure. Enzyme-linked immunosorbent assay kit and bicinchoninic acid kit were respectively adopted to measure IL-1ß and IL-4 protein expression and superoxide dismutase (SOD) activity and malondialdehyde (MDA) content in hippocampus and prefrontal cortex. RESULTS: AST improved the discrimination ability of VD mice. The escape latency and path length of VD mice treated with AST were dramatically reduced. Besides, AST 200 mg/kg enhanced crossing platform time and the number of times crossing the platform quadrant, and alleviated the morphological impairment in VD mice. Moreover, we found that AST inhibited IL-1ß expression and MDA content, whereas promoted IL-4 expression and SOD activity in a dose-dependent manner. CONCLUSION: AST could improve cognitive impairment and hippocampal neurons in VD mice, which may be related to suppression of inflammatory response and oxidative stress.

Structure-Based Rational and General Strategy for Stabilizing Single-Chain T-Cell Receptors to Enhance Affinity.

The T-cell receptor (TCR) is a crucial molecule in cellular immunity. The single-chain T-cell receptor (scTCR) is a potential format in TCR therapeutics because it eliminates the possibility of αß-TCR mispairing. However, its poor stability and solubility impede the in vitro study and manufacturing of therapeutic applications. In this study, some conserved structural motifs are identified in variable domains regardless of germlines and species. Theoretical analysis helps to identify those unfavored factors and leads to a general strategy for stabilizing scTCRs by substituting residues at exact IMGT positions with beneficial propensities on the consensus sequence of germlines. Several representative scTCRs are displayed to achieve stability optimization and retain comparable binding affinities with the corresponding αß-TCRs in the range of µM to pM. These results demonstrate that our strategies for scTCR engineering are capable of providing the affinity-enhanced and specificity-retained format, which are of great value in facilitating the development of TCR-related therapeutics.

[Improved generalized regression neural network for quantitative analysis of crude oil density by gas chromatography].

In the field of oil and gas exploration and development, the quick identification of reservoir crude oil properties has a guiding significance for engineers and technicians. Geochemical logging technology is a conventional method to evaluate the properties of crude oil in reservoirs, and it can provide professional knowledge for comprehensive evaluation of reservoirs. In this study, the principles of rock pyrolysis and gas chromatographic analyses in geochemical logging are studied. Moreover, a new method for quantitative analysis of crude oil density by chromatogram is proposed. Combined with the division standard of crude oil property density, the properties of reservoir crude oil can be quickly evaluated. In the experiment, first, the chromatogram was standardized and normalized using computer image processing software. The curve characteristic law of rock pyrolysis gas chromatogram was analyzed, and the corresponding characteristic parameter extraction method was proposed. The chromatogram was converted into a characteristic parameter matrix. Second, three types of artificial intelligence prediction and classification models were studied. The latest meta-heuristic optimization algorithm (sparrow search optimization algorithm) was used to optimize the hyperparameters of the generalized regression neural network, and the accuracy and convergence speed of the model were improved. To study the influence of different positions of rock samples on the experimental results, two groups of samples were utilized: cuttings samples and wall core samples. Based on a comprehensive comparison of the prediction results of the three models, it was found that the generalized regression neural network prediction model optimized by sparrow search algorithm provided the best effect, being a stable model, with small prediction density error, and strong generalization ability. The prediction error coincidence rate (absolute error < 0.02) of this model for cuttings and wall core samples was 95% and 100%, respectively. The root mean square errors were 0.0079 and 0.0069 respectively. The classification accuracy of crude oil properties was 95%. The analysis of the two groups of parallel experimental data indicated that the rock samples from the wall center can more accurately reflect the crude oil properties of the reservoir. Therefore, the method proposed in this study can provide reliable data support for reservoir comprehensive evaluation and on-site construction.

Analysis of the interprovincial embodied carbon flow network of China's exports.

We calculate the embodied carbon emissions of China's through the multiregional input-output (MRIO) method, then we construct the interprovincial embodied carbon flow networks of China's exports based on the mean threshold, and the application of complex network analysis to conduct a detailed examination of the overall characteristics, key nodes and edges, and community structure of China's interprovincial embodied carbon flow network. We extended the embodied carbon flow network analysis at the provincial level. The results demonstrated the following: (1) The interprovincial embodied carbon flow network of China's exports has small-world and scale-free characteristics. The node degree probability distribution curves for the networks obviously conformed to a decreasing power law distribution, indicating that a few industrial sectors carry a large amount of embodied carbon and suggesting that reducing the embodied carbon of China's exports could yield twice the results with half the effort as long as attention is paid to a few sectors. (2) The key nodes and edges in the networks show that industrial sectors and production chains such as the power and heat production and supply industry, the petroleum processing, coking, and nuclear fuel processing industry, and the metal smelting and calendering industry play the role of key "bridges" in the entire network, among which Guangdong, Hebei, Jiangsu, Inner Mongolia, and Shanxi are important node provinces and the main flow paths for the generation of embodied carbon in national exports. These industrial sectors and production chains should bolster their policies to encourage the innovation of carbon emission reduction technologies and decrease carbon emissions, so as to reduce the embodied carbon of national exports on a large scale. (3) The number of communities firstly increased then decreased from 2007 to 2017, while the aggregation coefficient of the node and correlation density within first community displayed firstly downward then upward trends, reflecting firstly decentralization then centralization of the interprovincial embodied carbon flow.

Phellopterin cream exerts an anti-inflammatory effect that facilitates diabetes-associated cutaneous wound healing via SIRT1.

BACKGROUND: Diabetic ulcers, which are characterized by chronic nonhealing wounds with a long-lasting inflammatory state, are a typical symptom in individuals with diabetes, and there is still no effective treatment for these lesions. Angelica dahurica plays a critical role in inflammatory diseases. Among numerous monomeric compounds, phellopterin has been shown to have anti-inflammatory properties. PURPOSE: To research the bioactive constituents in Angelica dahurica and their mechanism of action in treating diabetic ulcers. STUDY DESIGN: Chemical research of Angelica dahurica led to the identification of a new coumarin, dahuricoumarin A (1), along with seven known compounds (2 - 8). All compounds were tested for anti-inflammatory activity, and phellopterin, compound (3), significantly decreased the expression of intercellular cell adhesion molecule-1 (ICAM-1), a representative indicator of inflammation. Phellopterin can also increase SIRT1 protein, a key target for inflammation. In our research, we confirmed the anti-inflammatory effects of phellopterin on diabetic ulcers and explored the underlying mechanism of action. METHODS: The expression of IFN-γ, SIRT1, and ICAM-1 in human diabetic ulcer tissues was studied using immunohistochemistry. Streptozotocin was used to induce a diabetic model in C57BL/6J mice, and ulcers were surgically introduced. After phellopterin treatment, the skin lesions of diabetic mice were observed over a period of time. The protein and mRNA expression levels of SIRT1 and ICAM-1 were measured using H&E, qRT-PCR and immunohistochemical staining. A HaCaT cell inflammatory model was induced by IFN-γ. Using a lentiviral packaging technique, MTT assay, and Western blotting, the effect of phellopterin on the proliferation of HaCaT cells and the expression of ICAM-1 was evaluated under normal and SIRT1 knockdown conditions. RESULTS: High levels of ICAM-1 and IFN-γ were identified, but low levels of SIRT1 were found in human diabetic ulcer tissues, and phellopterin showed therapeutic benefits in the healing process by attenuating chronic inflammation and promoting re-epithelialization, along with SIRT1 upregulation and ICAM-1 downregulation. However, inhibiting SIRT1 reversed its proliferative and anti-inflammatory effects. CONCLUSION: In vitro and in vivo, phellopterin exerts anti-inflammatory and proliferative effects that promote diabetic wound healing, and the potential mechanism depends on SIRT1.

Does market segmentation hinder interregional CO2 flow in China? - Evidence from China's interprovincial MRIO table.

China is the key player in the globalization era and is eliminating its intra-national trade barrier. This process will affect interprovincial CO2 flows. This study recalculates interprovincial CO2 flows in China by using the latest MRIO table and applies a gravity model to assess how market segmentation affects interprovincial CO2 flows. Results show that the total volume of interprovincial embodied CO2 flow did not increase excessively from 2007 to 2012, but the pattern of embodied CO2 flow had changed a lot. Market segmentation significantly decreased the interprovincial embodied CO2 flows in China and within its sub-regions. At interregional level, market segmentation's negative effect was significant between Central and Western China. Other variables such as geographical distance showed a significant negative impact on interprovincial embodied CO2 flow in China. On the basis of our results, we raise some relevant policies to deal with the environmental inequality caused by the decrease in market segmentation.

Correction: Consumption substitution and change of household indirect energy consumption in China between 1997 and 2012.

[This corrects the article DOI: 10.1371/journal.pone.0221664.].

A Superior Potassium-Ion Anode Material from Pitch-based Activated Carbon Fibers with Hierarchical Pore Structure Prepared by Metal Catalytic Activation.

The pitch-based activated carbon fibers with nickel sulfide nanoparticles (ACF/NiS) were designed by in situ polymerization of ethylene tar with the addition of nickel nitrate followed by melt spinning, stabilization, carbonization, steam activation, and vulcanization processes. The ACF/NiS with hierarchical pore structure and abundant active sites was used as an anode material to improve Coulombic efficiency and increase capacity of potassium-ion batteries (PIBs). The results showed the obtained ACF/NiS with excellent specific surface area of 1552 m2 g-1 and high mesopore volume contribution of 38%, which delivered a high initial Coulombic efficiency of 84.22%, a high capacity of 292.5 mAh g-1, and retained 95.7% capacity retention after 200 cycles at 0.5 A g-1 current density. The NiS provided abundant active sites for the adsorption of potassium-ion, and the rich hierarchical structure shortened the electrolyte penetration path and expanded the storage space of potassium-ion, making it easier to store potassium-ion inside the ACF/NiS anode to obtain a better performance. This work presented one strategy for designing the hierarchical pore structure of pitch-based ACF to boost the capacity storage of PIBs and revealed that ACF-based carbon materials served as potential anodes for high-performance PIBs.

Consumption substitution and change of household indirect energy consumption in China between 1997 and 2012.

With the rapid growth in the Chinese economy in recent decades, household incomes as well as consumption of goods and services have also steadily increased. This has resulted in growing demand for energy consumption across the economy. It has been suggested that consumption upgrades in tandem with substitutions might exert an impact on mitigating this growth. The input-output method was applied in this study to analyze variations in household indirect energy consumption between 1997 and 2012. The impact of consumption substitution on change was also determined using a two-tier structural decomposition analysis, in which the second-tier is a further decomposition based on first-tier results. The results show that the indirect energy use caused by household consumption makes up between 75% and 78% of total household energy demand and that this increased 161.2% over the study period. First-tier decomposition results reveal that this change was mostly caused by household consumption scale and energy intensity effects. Second-tier decomposition results reveal strong evidence for consumption substitution between energy-intensive industries and non-energy-intensive ones and that this can have an impact on reducing household indirect consumption. Household consumption therefore plays a prominent role in total energy consumption. Transforming to non-energy-intensive or services led consumption patterns should therefore be encouraged by the Chinese government in order to achieve conservation goals.

Plasma miR-126 expression correlates with risk and severity of psoriasis and its high level at baseline predicts worse response to Tripterygium wilfordii Hook F in combination with acitretin.

BACKGROUND: Treatment of psoriasis is always difficult, which requires intensive scientific research. OBJECTIVE: Tripterygium wilfordii Hook F (TwHF) with acitretin(TwHF + acitretin) is normally used in treating psoriasis. This study aimed to investigate the correlation of plasma miR-126 expression with risk and severity of psoriasis, and its predictive value of response to TwHF + acitretin treatment in psoriasis. METHODS: MiRNA-126(MiR-126) expression in plasma was analyzed in psoriasis patients at month 0 (M0), M1, M3 and M6 and in health controls (HCs) at enrollment by qPCR. Psoriasis-affected body surface area (BSA) and Psoriasis Area and Severity Index (PASI) score were used to assess severity and treatment response. RESULTS: Plasma miR-126 levels were decreased in psoriasis patients compared with HCs (P < 0.001), with area under the curve (AUC) of 0.771. MiR-126 expression was negatively correlated with PASI score (P = 0.001), and negatively associated with psoriasis-affected BSA (P = 0.825). At M6, 65.3% and 36.1% patients achieved PASI 50 and 75, respectively. MiR-126 increased at M1, M3 and M6 after TwHF + acitretin treatment when comparing with M0 (all P < 0.001). Meanwhile, miR-126 expression baseline in PASI 50 group declined when comparing with non-PASI 50 group (P < 0.001). Additionally, data revealed that the cause of high miR-126 baseline level was due to unsuccessfully achieving PASI 50 at M6 after TwHF + acitretin treatment (P < 0.001). However, miR-126 baseline expression was not a predictive factor for PASI 75 achievement (P > 0.05). CONCLUSION: Plasma miR-126 expression is negatively correlated with psoriasis risk and severity, and its high baseline level can be used as a biomarker to predict worse clinical response to TwHF + acitretin treatment in psoriasis.

Clinicopathological and prognostic significance of GLUT1 in breast cancer: A meta-analysis.

BACKGROUND: Previous studies examining the prognostic value of glucose transporter 1 in breast cancer have yielded inconsistent results. We, therefore, performed a meta-analysis to clarify this issue. METHODS: The research was reported according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. Relevant studies were retrieved from PubMed, Web of Science, EMBASE, and Cochrane library. RESULTS: A total of 7 reports with 1861 patients were finally chosen. GLUT1 overexpression was found to be associated with high histological grade (OR = 3.74, 95% CI = 2.45-5.69, P < .001), negative PR status (OR = 0.33, 95% CI = 0.22-0.49, P < .001), and negative estrogen receptor (ER) status (OR = 0.27, 95% CI = 0.17-0.42, P < .001). However, no significant correlation was seen between GLUT1 levels and presence of lymph node metastasis, tumor size or the status of human epidermal growth factor receptor 2 (HER2). Overexpression of GLUT1 also correlated with a poor overall survival (hazard ratio [HR] = 1.65, 95% confidence interval [CI] = 1.17-2.31, P = .004) and disease-free survival (HR = 2.35, 95% CI = 1.4-3.94, P < .001). No evidence of significant publication bias was found. CONCLUSION: This meta-analysis indicates that GLUT1 expression is associated with poor prognostic and a series of clinicopathological features in breast cancer. GLUT1 might be a potential biomarker and therapeutic target in breast cancer.

Near-Infrared Triggered Upconversion Polymeric Nanoparticles Based on Aggregation-Induced Emission and Mitochondria Targeting for Photodynamic Cancer Therapy.

Photodynamic therapy (PDT) is an auspicious strategy for cancer therapy by yielding reactive oxygen species (ROS) under light irradiation. Here, we have developed near-infrared (NIR) triggered polymer encapsulated upconversion nanoparticles (UCNPs) based on aggregation-induced emission (AIE) characteristics and mitochondria target ability for PDT. The coated AIE polymer as a photosensitizer can be photoactivated by the up-converted energy of UCNPs upon 980 nm laser irradiation, which could generate ROS efficiently in mitochondria and induce cell apoptosis. Moreover, a "sheddable" poly(ethylene glycol) (PEG) layer was easily conjugated at the surface of NPs. The pH-responsive PEG layer shields the surface positive charges and shows stronger protein-resistance ability. In the acidic tumor environment, PEGylated NPs lose the PEG layer and show the mitochondria-targeting ability by responding to tumor acidity. A cytotoxicity study indicated that these NPs have good biocompatibility in the dark but exert severe cytotoxicity to cancer cells, with only 10% cell viability, upon being irradiated with an NIR laser. The AIE nanoparticles are a good candidate for effective mitochondria targeting photosensitizer for PDT.

Low-power white light triggered AIE polymer nanoparticles with high ROS quantum yield for mitochondria-targeted and image-guided photodynamic therapy.

Photodynamic therapy (PDT) has received enormous attention due to its high specificity in eliminating the malignant tumor cells without interposing normal cells, as compared with chemotherapy. In this work, we fabricated mitochondria-targeted NPs using a new AIE cross-linked copolymer (PAIE-TPP) with far red/near-infrared (FR/NIR) subcellular bioimaging ability and a high reactive oxygen species (ROS) quantum yield of 77.9%. Such high efficiency ROS generation is desirable to increase the efficiency of PDT. The PAIE-TPP NPs possess great cytocompatibility but exert severe cytotoxicity to cancer cells with only 4% of cell viability under ultralow-power-intensity (10 mW cm-2) light irradiation. The AIE cross-linked copolymer NPs not only emit bright FR/NIR fluorescence for efficient in vitro subcellular-mitochondrial bioimaging but also generate high ROS for PDT.

[Effects of Different Water Managements and Soil Eh on Migration and Accumulation of Cd in Rice].

A pot experiment was conducted to study the effects of four modes of water managements on soil Eh values,bioavailability of soil Cd,migration and accumulation of Cd in rice.These four modes of water managements were moistening throughout the entire period of rice growth (M),moistening before filling stage and flooding after filling stage (M-F),flooding before filling stage and moistening after filling stage (F-M),and flooding throughout the entire period of rice growth (F).The results indicated that the exchangeable contents of Cd increased firstly and then declined with the soil Eh values changing from negative to positive.Compared with M,the other three modes (M-F,F-M,and F) significantly reduced the contents of Cd in all rice tissues,including roots,stems,husks and brown rice.Meanwhile,Cd contents in brown rice due to the treatments of M-F and F were 0.19 mg·kg-1 and 0.10 mg·kg-1,respectively.These Cd contents were lower than the limits of 0.2 mg·kg-1 in national food safety standard (GB 2762-2012).Compared with M,the other three modes significantly decreased Cd accumulation amounts in the aboveground parts of rice and also decreased Cd translocation factors in rice.There were significant positive exponential relations between soil Eh values and Cd accumulation amounts in the aboveground parts of rice,Cd translocation factors in rice,or Cd contents in brown rice.The rice biomass due to M-F treatment reached the maximum among the four modes.It was worthy to be mentioned that although Weiyou 46 was considered a variety rice with high Cd accumulation,Cd content in rice brown of Weiyou 46 could be lower than 0.2 mg·kg-1 in the 5 mg·kg-1 of Cd contaminated soil through proper water managements.In summary,M-F treatment ensured high rice yield with low Cd contents in brown rice and could be recommended as the irrigation mode in rice production.Simultaneously,maintaining soil Eh value between -160--130 mV was also important after the filling stage.

[Synergetic Control of Bioavailability of Pb, Cd and As in the Rice Paddy System by Combined Amendments].

This paper studied the effects of applying two combined amendments LST (limestone+meerschaum+titanium dioxide) and LSF (limestone+meerschaum+ferric sulfate) at different ratios of 0, 1, 2, 4, 8 and 16 g·kg-1 on bioavailability Pb, Cd and As in paddy soil and bioaccumulation in rice plants through a pot experiment planting rice. The results indicated that: 1Compared with the control, applying LST and LSF could both significantly increase soil pH values (P<0.05), and LST increased the soil pH values more. 2Applying combined amendments LST and LSF with the amount of 1-16 g·kg-1 decreased exchangeable contents of soil Pb, Cd and As significantly by 16.8%-88.3%, 22.4%-73.7%, 2.25%-43.8%, and 20.2%-86.9%, 20.7%-51.2%, 18.0%-55.1%, respectively. LST and LSF significantly decreased contents of Pb, Cd and As of rice root, shoot, husk and brown rice. When the applying amount of LST and LSF was 16 g·kg-1, the contents of Pb, Cd and As in brown rice decreased by 50.7%, 64.7%, 34.1%, and 40.7%, 40.7%, 36.2%, respectively. 3The ability of rice organs transferring Pb and As was husk>rice straw>root, and that transferring Cd was husk >root >rice straw. The ability to transfer Pb, Cd and As from rice straw to brown rice was Cd >As >Pb. 4After applying LST and LSF, a significant positive relationship was observed between contents of Pb, Cd and As in brown rice and exchangeable contents of these elements in soil. Between contents of Pb, Cd and As in brown rice and soil pH values, there was a significant negative correlation.

Impacts of rapeseed dregs on Cd availability in contaminated acid soil and Cd translocation and accumulation in rice plants.

The objective of the present study was to investigate the effects of rapeseed dregs (RSD, a commonly organic fertilizer in rural China) at application rates of 0, 0.75, 1.5, and 3.0 % on Cd availability in soil and its accumulation in rice plants (Oryza sativa L., Xiangwanxian 12#, and Weiyou 46#) by means of a pot experiment. The results showed that application of RSD resulted in a sharp decrease in the soil TCLP-extractable Cd content. However, the soil TCLP-extractable Cd content in amended soil gradually increased during the rice growing period. Application of RSD significantly increased Cd transport from root to shoot and the amount of Cd accumulated in the aerial part. RSD was an effective organic additive for increasing rice grain yield, but total Cd content in rice grain was also increased. At an application rate of 1.5-3.0 % RSD, the total Cd content in Weiyou 46# brown rice was 0.27-0.31 mg kg-1, which exceeded the standard safe limit (0.2 mg kg-1) and was also higher than that of Xiangwanxian 12# (0.04-0.14 mg kg-1). Therefore, Weiyou 46# had a higher dietary risk than Xiangwanxian 12# with RSD application. We do not recommend planting Weiyou 46# and applying more than 0.75 % RSD in Cd-contaminated paddy fields.