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In subway construction, the presence of boulders can significantly impact excavation and tunneling processes. However, despite these challenges, an effective and reliable method for detecting boulders in advance has not yet been established. This paper presents a novel method for detecting and characterizing boulders using 3D cross-hole electrical resistivity tomography (ERT). The proposed technique involves the strategic deployment of multiple borehole electrodes, which work together to create a comprehensive three-dimensional resistivity model of the subsurface. This model allows for the identification and characterization of boulders, providing crucial information about their location and size. We demonstrate the efficacy of this approach in a physical flume experiment and a case study of subway construction, The findings from both the laboratory and field studies indicate that the 3D cross-hole ERT method is not only effective in detecting boulders and providing detailed information about their size and spatial distribution but also optimizes construction planning, reduces unexpected disruptions and additional costs, and enhances overall construction safety. The results highlight the potential of 3D cross-hole ERT as a valuable tool for geological assessments during infrastructure development. [ABSTRACT FROM AUTHOR]

Because of its long processing time, low operating cost, simultaneous processing of multiple pollutants, PRB (permeable reactive barrier) is a commonly used technique for groundwater pollution remediation in western countries. But relative research about the PRB technology in China is still in its infancy. We reviewed the PRB structure, PRB repair mechanism and application progress at home and abroad. Aiming at the problems of PRB technology at reaction material selection, pollutant repair mechanism, removal of various pollution components and site installation design, development direction of the PRB technology was prospected. [ABSTRACT FROM AUTHOR]

Liujiang basin is located in a typical rural mountain area dominated by agriculture and mining industry in Qinhuangdao, Hebei Province of China. Groundwater plays significant role for socioeconomic development in the area. 78 well samples and 11 spring samples showed great variation of chemical compositions and groundwater quality class across the study basin. Groundwater hydrochemical type in Liujiang basin is mainly dominated by the typical Ca Mg-HCO SO or Ca Mg-SO HCO. The relative abundance of constituents is in the following order: Ca > Mg > Na > K for cations and HCO > SO > Cl for anions. Spring water quality is all good for drinking and irrigation, whereas about 33.00 % of the well water samples were not suitable for drinking and the exceeding indices included NO, total hardness, total dissolved solids and SO, and seven well samples were not suitable for agriculture use. The control of sodium and salinity hazard is required for irrigation. Natural processes include weathering-dominated, mineral weathering and ion exchange controlling groundwater chemistry. Principal component analysis and Pearson correlation matrices were used to identify groundwater contaminant sources and can be categorized as follows: (1) natural minerals dissolution and mine water mixing (2) domestic sewage and septic tank contamination and (3) agricultural fertilizer contamination. This study suggested that both natural and anthropogenic processes contributed to chemical composition of groundwater in Liujiang basin, especially the NO concentration is more than the acceptable limits in groundwater used for drinking purposes, indicating that anthropogenic nitrogen pollution is currently serious. [ABSTRACT FROM AUTHOR]

Background: One-third to half of IgA nephropathy (IgAN) patients have raised serum IgA levels. Decreased clearance of IgA/IgA complex has been observed in IgAN patients. FCAR codes for IgA-specific receptor and plays an important role in IgA metabolism. Previous small sample-sized studies reported controversial findings in its association with IgAN., Methods: We re-sequenced the FCAR in 107 IgAN patients and 112 controls. Association of -27T/C and their haplotypes were performed in 606 patients versus 606 controls, its two independent subsets: 293 single patients with family members and 313 cases versus 606 controls. Functional impact of -27T>C and their haplotypes were analyzed by bioinformatics, allelic differential expression and luciferase activity assays. Cell surface FCAR density between -27T/C heterozygous patients and -27T/T homozygous controls was assessed by flow cytometry., Results: -27T>C, on the consensus TATA box of transcription factor-binding motif in the putative promoter of the gene was the only variation identified in all coding, splice-site and known protein-binding sequence in re-sequencing. -27C and its haplotype were associated with IgAN (P = 0.0034/0.0013, 0.0099/0.0054, 0.0129/0.0076 and 0.00039/0.00014 in 606 cases versus 606 controls, family-based study, 313 cases versus 606 controls and meta-analysis, respectively). Bioinformatics predicted 2 bp binding changes by -27C. Allelic differential expression and luciferase activity assays showed a reduced expression/activity by the associated haplotype/allele (P < 0.001). -27T/C heterozygous patients had a lower receptor density on cell surface compared to -27T/T homozygous controls (P < 0.001)., Conclusions: Our results provide evidence for genetic variation at the putative promoter region of FCAR conferring susceptibility to IgAN, suggesting -27C and its haplotype may be causative for the susceptibility among the Chinese Han population.