33 research outputs found

    Chlorogenic Acid Decreases Intestinal Permeability and Increases Expression of Intestinal Tight Junction Proteins in Weaned Rats Challenged with LPS

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    Chlorogenic acid, a natural phenolic acid present in fruits and plants, provides beneficial effects for human health. The objectives of this study were to investigate whether chlorogenic acid (CHA) could improve the intestinal barrier integrity for weaned rats with lipopolysaccharide (LPS) challenge. Thirty-two weaned male Sprague Dawley rats (21 ± 1 d of age; 62.26 ± 2.73 g) were selected and randomly allotted to four treatments, including weaned rat control, LPS-challenged and chlorogenic acid (CHA) supplemented group (orally 20 mg/kg and 50 mg/kg body). Dietary supplementation with CHA decreased (P<0.05) the concentrations of urea and albumin in the serum, compared to the LPS-challenged group. The levels of IFN-γ and TNF-α were lower (P<0.05) in the jejunal and colon of weaned rats receiving CHA supplementation, in comparison with the control group. CHA supplementation increased (P<0.05) villus height and the ratio of villus height to crypt depth in the jejunal and ileal mucosae under condictions of LPS challenge. CHA supplementation decreased (P<0.05) intestinal permeability, which was indicated by the ratio of lactulose to mannitol and serum DAO activity, when compared to weaned rats with LPS challenge. Immunohistochemical analysis of tight junction proteins revealed that ZO-1 and occludin protein abundances in the jejunum and colon were increased (P<0.05) by CHA supplementation. Additionally, results of immunoblot analysis revealed that the amount of occludin in the colon was also increased (P<0.05) in CHA-supplemented rats. In conclusion, CHA decreases intestinal permeability and increases intestinal expression of tight junction proteins in weaned rats challenged with LPS

    Robust estimation of bacterial cell count from optical density

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    Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals &lt;1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

    Design of an Electric Road-Rail Vehicle

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    In this paper, an electric road-rail vehicle and its control system are designed. The electric vehicle equipped a train couplers in front of it is used as a movable electric signal test bench for China Rail High-speed (CRH). Firstly, architecture of the vehicle is introduced. In the powertrain, hydraulic system is designed for the transition from road mode to rail mode, and vice versa. And in both road and rail modes, the vehicle is driven by an induction machine. Secondly, to improve the driving performance and satisfy different driving conditions, particular control strategy for the induction machine is put forward by using a load torque observer based on sliding mode control theory. The load observer based induction machine control system can improve the speed stability and robustness to the unexpected load disturbing. Finally, experiment is done and the results verify that the algorithm works well

    Design of an Electric Road-Rail Vehicle

    No full text
    In this paper, an electric road-rail vehicle and its control system are designed. The electric vehicle equipped a train couplers in front of it is used as a movable electric signal test bench for China Rail High-speed (CRH). Firstly, architecture of the vehicle is introduced. In the powertrain, hydraulic system is designed for the transition from road mode to rail mode, and vice versa. And in both road and rail modes, the vehicle is driven by an induction machine. Secondly, to improve the driving performance and satisfy different driving conditions, particular control strategy for the induction machine is put forward by using a load torque observer based on sliding mode control theory. The load observer based induction machine control system can improve the speed stability and robustness to the unexpected load disturbing. Finally, experiment is done and the results verify that the algorithm works well

    Exogenous supplement of N-acetylneuraminic acid improves macrophage reverse cholesterol transport in apolipoprotein E-deficient mice

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    Abstract Background N-acetylneuraminic acid (NANA) is the major form of sialic acid in mammals, and the plasma NANA level is increased in patients with cardiovascular diseases. Exogenous supplement of NANA has been demonstrated to reduce hyperlipidaemia and the formation of atherosclerotic lesions; however, the underlying mechanisms have not yet been clarified. The aim of this study is to investigate whether exogenous supplement of NANA improves reverse cholesterol transprot (RCT) in vivo. Methods Apolipoprotein E-deficient mice fed a high-fat diet were used to investigate the effect of NANA on RCT by [3H]-cholesterol-loaded macrophages, and the underlying mechanism was further investigated by various molecular techniques using fenofibrate as a positive control. Results Our novel results demonstrated that exogenous supplement of NANA significantly improved [3H]-cholesterol transfer from [3H]-cholesterol-loaded macrophages to the plasma (an increase of > 42.9%), liver (an increase of 35.8%), and finally to the feces (an increase of 50.4% from 0 to 24 h) for excretion in apolipoprotein E-deficient mice fed a high-fat diet. In addition, NANA up regulated the protein expression of ATP-binding cassette (ABC) G1 and peroxisome proliferator-activated receptor α (PPARα), but not the protein expression of ABCA1and scavenger receptor B type 1 in the liver. Therefore, the underlying mechanism of NANA in improving RCT may be partially due to the elevated protein levels of PPARα and ABCG1. Conclusion Exogenous supplement of NANA improves RCT in apolipoprotein E-deficient mice fed a high-fat diet mainly by improving the protein expression of PPARα and ABCG1. These results are helpful in explaining the lipid-lowering effect of NANA

    High-resolution DNA methylome reveals that demethylation enhances adaptability to continuous cropping comprehensive stress in soybean

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    Abstract Background Continuous cropping stress involves such factors as biological barriers, allelopathic autotoxicity, deterioration of soil physicochemical properties, and soil fertility imbalance and is regarded as a kind of comprehensive stress limiting soybean yield and quality. Genomic DNA methylation is an important regulatory mechanism for plants to resist various environmental stresses. Therefore, it is especially worthwhile to reveal genomic methylation characteristics under stress and clarify the relationship between DNA methylation status and continuous cropping stress adaptability in soybean. Results We generated a genome-wide map of cytosine methylation induced by this kind of comprehensive stress in a tolerant soybean variety (Kang Xian 2, KX2) and a sensitive variety (He Feng, HF55) using whole-genome bisulfite sequencing (WGBS) technology. The expression of DNA demethylase genes was detected using real-time quantitative PCR (qRT-PCR). The functions of differentially methylated genes (DMGs) involved in stress response in biochemical metabolism and genetic information transmission were further assessed based on Gene Ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. The results showed that genomic DNA demethylation was closely related to continuous cropping comprehensive stress adaptability in soybean, which was further verified by the increasing expression of DNA demethylases ROS1 and DML. The demethylation of mCpG and mCpHpG (mCpApG preferred) contexts was more critical, which mainly occurred in gene-regulatory regions at the whole-chromosome scale. Moreover, this kind of stress adaptability may be related to various stress responders generated through strengthened glucose catabolism and amino acid and fatty acid anabolism, as well as fidelity transmission of genetic information. Conclusions Genomic DNA demethylation was closely associated with continuous cropping comprehensive stress adaptability, highlighting the promising potential of screening continuous cropping-tolerant cultivars by DNA methylation index and further exploring the application of DNA demethylases in soybean breeding
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