8 research outputs found

    Analytical solution for one-dimensional consolidation in layered filled soil based on continuous boundary conditions

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    The newly filled soil in reclamation areas shows a significant consolidation effect, resulting in severe ground settlements and inducing extremely adverse impacts on the stability of foundations on site. Based on the continuous boundary conditions, this paper establishes a one-dimensional filled soil-native seabed consolidation theory with consideration of the self-weight of the filled soil and the bedding characteristics of the seabed simultaneously, and derives an analytical solutions to the response of the excess pore water pressure and the consolidation degree through the eigenfunction method. The proposed solution is subsequently verified through the degradation of the boundary conditions and mathematical models. By virtue of the proposed solution, a parametric study is conducted to investigate the influence of the spatio-temporal impact factors (including the self-weight of the filled soil, moduli of the filled soil, time factor, and additional load at ground) on the consolidation. The main conclusions can be drawn as follows: â‘ The self-weight of the filled soil drives the consolidation of the newly filled ground and should not be ignored in practical engineering. â‘¡The effect of the permeability coefficient on the dissipation of the excess pore water pressure is relatively complicated. In case of change in the penetrability of a certain soil layer, it will have opposite influences on the excess pore water pressure of the overlying and underlying soil layers. â‘¢The volume compressibility of the soil has a significant influence on the excess water pressure. And the influence of the volume compressibility of the deeply buried soil is more significant. â‘£The additional load caused by, for instance, the stacking at the ground, will slow down the consolidation of the site

    Nonlinear consolidation of arbitrary layered soil with continuous drainage boundary: An approximate closed-form solution

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    Based on the double nonlinear consolidation constitutive associated with the compression and permeability coefficients, presented by Mesri and Rokhsar (1974), this paper derives an approximate closed-form solution for the one-dimensional nonlinear consolidation of the arbitrary layered soils incorporating the continuous drainage boundary condition. The approximate closed-form solution is obtained by the homogenization of the boundary conditions and eigenfunction method. A model test is conducted to justify the rationality of the approximation and the continuous drainage condition utilized in this study. The calculated results are also compared with those acquired from the simplified analytical solution and the finite difference method. A parametric study is conducted to investigate the influence of various parameters on the consolidation process. The most significant finding is that the influence of Nq appears to be completely different for the cases when Cc/Ck>1 and Cc/Ck1, the increase of Nq shows an adverse influence on the consolidation, whereas the influence becomes positive when Cc/Ck<1. The approximate solution derived herein offers a rigorous analytical approach for the double nonlinear consolidation problems of arbitrary layered soils, providing an effective benchmark for comparison and verification of future sophisticated numerical approaches

    Lactiplantibacillus plantarum enables blood urate control in mice through degradation of nucleosides in gastrointestinal tract

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    Abstract Background Lactobacillus species in gut microbiota shows great promise in alleviation of metabolic diseases. However, little is known about the molecular mechanism of how Lactobacillus interacts with metabolites in circulation. Here, using high nucleoside intake to induce hyperuricemia in mice, we investigated the improvement in systemic urate metabolism by oral administration of L. plantarum via different host pathways. Results Gene expression analysis demonstrated that L. plantarum inhibited the activity of xanthine oxidase and purine nucleoside phosphorylase in liver to suppress urate synthesis. The gut microbiota composition did not dramatically change by oral administration of L. plantarum over 14 days, indicated by no significant difference in α and β diversities. However, multi-omic network analysis revealed that increase of L. plantarum and decrease of L. johnsonii contributed to a decrease in serum urate levels. Besides, genomic analysis and recombinant protein expression showed that three ribonucleoside hydrolases, RihA–C, in L. plantarum rapidly and cooperatively catalyzed the hydrolysis of nucleosides into nucleobases. Furthermore, the absorption of nucleobase by intestinal epithelial cells was less than that of nucleoside, which resulted in a reduction of urate generation, evidenced by the phenomenon that mice fed with nucleobase diet generated less serum urate than those fed with nucleoside diet over a period of 9-day gavage. Conclusion Collectively, our work provides substantial evidence identifying the specific role of L. plantarum in improvement of urate circulation. We highlight the importance of the enzymes RihA–C existing in L. plantarum for the urate metabolism in hyperuricemia mice induced by a high-nucleoside diet. Although the direct connection between nucleobase transport and host urate levels has not been identified, the lack of nucleobase transporter in intestinal epithelial cells might be important to decrease its absorption and metabolization for urate production, leading to the decrease of serum urate in host. These findings provide important insights into urate metabolism regulation. Video Abstrac

    Additional file 2 of Lactiplantibacillus plantarum enables blood urate control in mice through degradation of nucleosides in gastrointestinal tract

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    Additional file 2: Figure S1. Changes in metabolic parameters due to high nucleosides diet and L. plantarum supplementation in mice. Supplementary Fig. 2. Changes in gut microbiota due to high nucleosides diet and L. plantarum supplementation in mice. Supplementary Fig. 3. L. plantarum affecting the gut metabolites. Supplementary Fig. 4. Metagenomic functional annotation and classification of L. plantarum in KEGG (A) and in COG (B). Supplementary Fig. 5. Identification of production of inosine hydrolyzed by L. plantarum. Supplementary Fig. 6. Established Caco-2 cell monolayer for nucleosides and nucleobases transport. Supplementary Fig. 7. Gene sequences alignment of RihA–C from L. plantarum with other organisms

    Additional file 1 of Lactiplantibacillus plantarum enables blood urate control in mice through degradation of nucleosides in gastrointestinal tract

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    Additional file 1: Table S1. Primer sequence of genes in this work. Table S2. Fifteen differential genera in mice supplemented L. plantarum when compared with HNS mice. Table S3. Taxonomy of six microbes using NCBI Nucleotide BLAST analysis tool. Table S4. Three genes involved with nucleoside degradation in L. plantarum. Table S5. Annotated genes contributed to the nucleotide and nucleoside metabolism, which showed that no enzyme in L. plantarum enable to catalyze the transformation of guanine and hypoxanthine into xanthine and resultant urate. Table S6. Genes involved with purine permeation in L. plantarum. Table S7. Permeation for nucleobases in L. plantarum within 2 hours. Table S8. Solubility of nucleosides and nucleobases in water. Table S9. Nodes information in multi-omic network analysis given by Fig. 2A. Table S10. Edges information in multi-omic network analysis given by Fig. 2A. Table S11. Nodes information in multi-omic network analysis given by Fig. S3C. Table S12. Edges information in multi-omic network analysis given by Fig. 3C
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