Study on Mud-Water Separation Test Technology for Shield Slurry in Underground Tunnel

( Changhong Yan ),( Shulan Guo ),( Liang Wen ),( Liangwei Li ),( Xiaoyong Yang ),( Zhiwei Jin ),( Xuyang Fan ) 대한지질공학회 2019 대한지질공학회 학술발표회논문집 Vol.2019 No.2

The construction of urban subway produced a large amount of slurry with hign moisture content. In order to ensure the stability of the excavation face during the construction of the tunnel shield, prevent the spoil from adhering to the shield cutter, a large amount of additives such as water, bentonite, foaming agent are added to the spoil. Therefore, the slurry has the characteristics of uneven particle composition, high moisture content, low permeability and remarkable plastic flow, and its shear strength is almost zero. The transportation and stacking of slurry can cause environmental pollution and damage the ecological environment. To solve this problem, our research team developed a set of mud-water separation test device to carry out research on mud-water separation technology. The Optimal treatment plan for mud-water separation is given by a large number of laboratory tests: when the moisture content of slurry is relatively high, the vacuum negative pressur is firstly used to discharge the free water. When the moisture content drops below the liquid limit, the electroosmosis and the vacuum negative pressure are combined to discharge the bound water, at which time the moisture content in the slurry is close to the plastic limit, thereby achieving slurry hardening. This method has a fast drainage speed and low cost, and has been successfully applied to the Suzhou Metro. It is not only conducive to the resource utilization of slurry, but more importantly, it can effectively protect the ecological environment.

Research on Mechanism of Temporary Confined Groundwater in the Intermittent Creep Landslide in Ningzhen Area

( Changhong Yan ),( Shulan Guo ),( Jinzhong Tan ),( Yang Liu ),( Baotian Xu ) 대한지질공학회 2019 대한지질공학회 학술발표회논문집 Vol.2019 No.2

In recent years, due to the influence of extreme heavy rainfall weather, many large scale landslides occurred on the gentle slopes in Ningzhen area, which characteristically intermittent creep, large scale, and small slip distance (generally less than 30 m). The surface of gentle slope is dominated by fine-grained soil, while the middle and lower layers are dominated by coarse-grained soil, gravel or weathered rockmass, forming a special "binary stratigraphic structure" and the permeability of the soil layer is weak-strong-weak from top to bottom. Under the condition of heavy rainfall weather extremes, the bare rockmass fracture of upper mountain in favor of rainfall infiltration. The middle mountain by precipitation process prone to circular sliding, the lower part of the gentle slope is easy to form “Temporary confined groundwater”, which is prone to landslide under the combined with downslide force of the middle slide body. Based on this new type of landslide geological hazard, the stratum structure and sliding mechanism of the landslide had been researched by using the cybernetics of rockmass structure and preferred plane theory.

The Study of Special Geological Environment Conditions in the Design of Supporting Structures for Large and Unusually Shaped Foundation Pits

( Shulan Guo ),( Changhong Yan ),( Liangchen Yu ),( Zhanyong Yang ),( Qingming Wang ) 대한지질공학회 2019 대한지질공학회 학술발표회논문집 Vol.2019 No.2

A large underground transportation hub, which was completed in 2016, is located on the west side of the Nanjing Youth Olympic Center, which is close to the embankment of the Yangtze River. The foundation pit for the hub is of an unusual shape and variable depth, and has required deep excavation. A further complicating factor in construction has been the area’s wide distribution of loose sediments of Quaternary age. The near-surface is primarily comprised of newly deposited soft soil of considerable thickness; the lower part is a riverbed-phase sandy soil containing rich groundwater, and most of it is confined. The B2-J1 area is the core area of the project. The bottoms of the foundation pits were located in the layers of B, C1, and C2, which exhibit poor stability. The site is also close to the Yangtze River, which is characterized by high-level groundwater. After considering the engineering geological conditions, the potential associated geological problems, and the function and shape of the foundation pits, we divided the soil layers of the foundation pits into two areas (the NW area and the SE area). The support structure was designed for the “pit in pit” and the “pit leaning pit” phenomena of the two areas, and the support effect was verified via FLAC3D numerical simulation software.

Systematic Investigation of the Effects of Macro-elements and Iron on Soybean Plant Response to Fusarium oxysporum Infection

Hongsheng Cai,Nan Tao,Changhong Guo 한국식물병리학회 2020 Plant Pathology Journal Vol.36 No.5

Nutrient manipulation is a promising strategy for controlling plant diseases in sustainable agriculture. Although many studies have investigated the relationships between certain elements and plant diseases, few have comprehensively explored how differing mineral nutrition levels might affect plant–fungal pathogen interactions, namely plant susceptibility and resistance. Here, we systematically explored the effects of the seven mineral elements that plants require in the greatest amounts for normal development on the susceptibility of soybean plants (Glycine max) to Fusarium oxysporum infection in controlled greenhouse conditions. Nitrogen (N) negligibly affected plant susceptibility to infection in the range 4 to 24 mM for both tested soybean cultivars. At relatively high concentrations, phosphorus (P) increased plant susceptibility to infection, which led to severely reduced shoot and root dry weights. Potassium (K), calcium (Ca), magnesium (Mg), sulfur (S), and iron (Fe) induced plant resistance to infection as their concentrations were increased. For K and Ca, moderate concentrations had a positive effect on plant resistance to the pathogen, whereas relatively high doses of either element adversely affected plant growth and promoted disease symptoms. Further experiments were conducted, assessing disease suppression by selected combinations of macro-elements and Fe at screened concentrations, i.e., K (9 mM) plus Fe (0.2 mM), and S (4 mM) plus Fe (0.2 mM). The disease index was significantly reduced by the combination of K plus Fe. In conclusion, this systematic investigation of soybean plant responses to F. oxysporum infection provides a solid basis for future environmentally-friendly choices for application in soybean disease control programs.

Comparative genomics of 151 plant-associated bacteria reveal putative mechanisms underlying specific interactions between bacteria and plant hosts

Hongsheng Cai,Yan Bai,Changhong Guo 한국유전학회 2018 Genes & Genomics Vol.40 No.8

Although much work has explored how microbes can benefit plant growth, the mechanisms underlying this intriguing process remain largely unknown, especially considering the diversity of bacteria that surrounds plants. The objective of the present study was to identify bacterial genes contributing to plant–microbe associations, beneficial effects, and host specificities. For this purpose, comparative genomics investigation of 151 plant-associated bacteria was performed. A principal component analysis of seven key genomic features revealed patterns in the specific properties of these bacteria: N2- fixing bacteria were more closely related to pathogenic ones than to beneficial bacteria. A common set of genes over-represented in these plant-associated bacteria were found to be remarkably similar in terms of (1) genetic information processing, (2) amino acid metabolism, (3) metabolism of cofactors and vitamins, (4) nucleotide metabolism, (5) human diseases, and (6) metabolism of terpenoids and polyketides. Although we did not detect a common genetic basis for these beneficial effects, further in-depth analysis revealed that each of five beneficial bacterial groups shared specific gene sets. Functional annotation showed that environmental information processing, genetic information processing and cellular processes predominated in these beneficial groups. Hypothesizing that plant-associated bacteria may have overlapping strategies to colonize their plant hosts, we successfully identified many putative genes that determine host specificities. Most of these genes were classified as transcription factors, enzymes, transporters, and chemotaxis regulators. Comparative genomics provides a powerful tool for helping to identify genes that are common among species. Genome-based views of plant-associated bacteria reveal specific interactions between bacteria and plant hosts.

The effects of nitrobenzene on the genetic toxicity in tobacco seedling leaf cells by comet assay

Zening Yuan,Yuwei Cao,Liang Si,Dehui Wang,Changhong Guo 대한독성 유전단백체 학회 2011 Molecular & cellular toxicology Vol.7 No.3

Nitrobenzene (NB) is a synthetic hydrocarbon widely used in industries which is a highly toxic environmental pollutant. To investigate its genetic toxicity to plants, tobacco seedlings were exposed to varying concentration of NB solution for short-term (24hours). The comet assay was used to examine the DNA damage in tobacco leaf cells under the stress of NB. The DNA migration increased with the dose of NB (from 10 to 100 mg/L). The values of tail intensity (TDNA),tail moment (TM), and olive tail moment (OTM)increased linearly with NB concentrations between 5mg/L and 100 mg/L. The results suggest that NB has genotoxic effect on the molecular level in tobacco leaf cells. The comet parameters were significantly different from the control when NB concentrations were higher than 5 mg/L (P⁄0.05), suggesting that tobacco leaf cells have high sensitivity to NB stress. The phenomena demonstrated that the tobacco comet assay could be used efficiently monitor aquatic pollution caused by the toxic chemicals. In addition, a similar evaluation was performed using different NB and antioxidant ascorbic acid (Vc) mixed solutions. The DNA damage in the antioxidant group were significantly lower than those in the group without antioxidant, which illustrates that antioxidants could partially decrease the DNA damage induced by NB. These results suggest that oxidation reactions caused by NB might be one of the factors that lead to DNA damage in plants. However, to process the possible participation of mechanisms of DNA damage caused by NB, further investigation will need.

Cloning, Annotation and Expression Analysis of Mycoparasitism- Related Genes in Trichoderma harzianum 88

Lin Yao,Qian Yang,Jinzhu Song,Chong Tan,Changhong Guo,Li Wang,Lianhai Qu,Yun Wang 한국미생물학회 2013 The journal of microbiology Vol.51 No.2

Trichoderma harzianum 88, a filamentous soil fungus, is an effective biocontrol agent against several plant pathogens. High-throughput sequencing was used here to study the mycoparasitism mechanisms of T. harzianum 88. Plate confrontation tests of T. harzianum 88 against plant pathogens were conducted, and a cDNA library was constructed from T. harzianum 88 mycelia in the presence of plant pathogen cell walls. Randomly selected transcripts from the cDNA library were compared with eukaryotic plant and fungal genomes. Of the 1,386 transcripts sequenced, the most abundant Gene Ontology (GO) classification group was “physiological process”. Differential expression of 19 genes was confirmed by real-time RT-PCR at different mycoparasitism stages against plant pathogens. Gene expression analysis revealed the transcription of various genes involved in mycoparasitism of T. harzianum 88. Our study provides helpful insights into the mechanisms of T. harzianum 88-plant pathogen interactions.

Distribution and Pathogenicity of Fusarium Species Associated with Soybean Root Rot in Northeast China

Yingying Liu,Xuena Wei,Feng Chang,Na Yu,Changhong Guo,Hongsheng Cai 한국식물병리학회 2023 Plant Pathology Journal Vol.39 No.6

Fusarium root rot is an increasingly severe problem in soybean cultivation. Although several Fusarium species have been reported to infect soybean roots in Heilongjiang province, their frequency and aggressiveness have not been systematically quantified in the region. This study aimed to investigate the diversity and distribution of Fusarium species that cause soybean root rot in Heilongjiang province over two years. A total of 485 isolates belonging to nine Fusarium species were identified, with F. oxysporum and F. solani being the most prevalent. Pot experiments were conducted to examine the relative aggressiveness of different Fusarium species on soybean roots, revealing that F. oxysporum and F. solani were the most aggressive pathogens, causing the most severe root rot symptoms. The study also assessed the susceptibility of different soybean cultivars to Fusarium root rot caused by F. oxysporum and F. solani. The results indicated that the soybean cultivar DN51 exhibited the most resistance to both pathogens, indicating that it may possess genetic traits that make it less susceptible to Fusarium root rot. These findings provide valuable insights into the diversity and distribution of Fusarium species that cause soybean root rot and could facilitate the development of effective management strategies for this disease.

Single-cell transcriptomic analysis reveals transcriptional and cell subpopulation differences between human and pig immune cells

Li Jie,Xu Yanan,Zhang Jiayu,Zhang Zhaoqi,Guo Han,Wei Dong,Wu Changhong,Hai Tang,Sun Hai-Xi,Zhao Yong 한국유전학회 2024 Genes & Genomics Vol.46 No.3

Background The pig is a promising donor candidate for xenotransplantation. Understanding the differences between human and swine immune systems is critical for addressing xenotransplant rejection and hematopoietic reconstitution. The gene transcriptional profile differences between human and pig immune cell subpopulations have not been studied. To assess the similarities and differences between pigs and humans at the levels of gene transcriptional profiles or cell subpopulations are important for better understanding the cross-species similarity of humans and pigs, and it would help establish the fundamental principles necessary to genetically engineer donor pigs and improve xenotransplantation. Objective To assess the gene transcriptional similarities and differences between pigs and humans. Methods Two pigs and two healthy humans’ PBMCs were sorted for 10 × genomics single-cell sequence. We generated integrated human-pig scRNA-seq data from human and pig PBMCs and defined the overall gene expression landscape of pig peripheral blood immune cell subpopulations by updating the set of human-porcine homologous genes. The subsets of immune cells were detected by flow cytometry. Results There were significantly less T cells, NK cells and monocytes but more B cells in pig peripheral blood than those in human peripheral blood. High oxidative phosphorylation, HIF-1, glycolysis, and lysosome-related gene expressions in pig CD14+ monocytes were observed, whereas pig CD14+ monocytes exhibited lower levels of cytokine receptors and JAK-STAT-related genes. Pig activated CD4+T cells decreased cell adhesion and inflammation, while enriched for migration and activation processes. Porcine GNLY+CD8+T cells reduced cytotoxicity and increased proliferation compared with human GNLY+CD8+T cells. Pig CD2+CD8+γδT cells were functionally homologous to human CD2+CD4+ γδT cells. Pig CD2−CD8−γδT cells expressed genes with quiescent and precursor characteristics, while CD2−CD8+γδT cells expressed migration and memory-related molecules. Pig CD24+ and CD5+B cells are associated with inflammatory responses. Conclusion Our research with integrated scRNA-seq assays identified the different distribution of pig immune cell subpopulations and the different transcriptional profiles of human and pig immune cells. This study enables a deeper understanding of the development and function of porcine immune cells. Background The pig is a promising donor candidate for xenotransplantation. Understanding the differences between human and swine immune systems is critical for addressing xenotransplant rejection and hematopoietic reconstitution. The gene transcriptional profile differences between human and pig immune cell subpopulations have not been studied. To assess the similarities and differences between pigs and humans at the levels of gene transcriptional profiles or cell subpopulations are important for better understanding the cross-species similarity of humans and pigs, and it would help establish the fundamental principles necessary to genetically engineer donor pigs and improve xenotransplantation. Objective To assess the gene transcriptional similarities and differences between pigs and humans. Methods Two pigs and two healthy humans’ PBMCs were sorted for 10 × genomics single-cell sequence. We generated integrated human-pig scRNA-seq data from human and pig PBMCs and defined the overall gene expression landscape of pig peripheral blood immune cell subpopulations by updating the set of human-porcine homologous genes. The subsets of immune cells were detected by flow cytometry. Results There were significantly less T cells, NK cells and monocytes but more B cells in pig peripheral blood than those in human peripheral blood. High oxidative phosphorylation, HIF-1, glycolysis, and lysosome-related gene expressions in pig CD14+ monocytes were observed, whereas pig CD14+ monocytes exhibited lower levels of cytokine receptors and JAK-STAT-related genes. Pig activated CD4+T cells decreased cell adhesion and inflammation, while enriched for migration and activation processes. Porcine GNLY+CD8+T cells reduced cytotoxicity and increased proliferation compared with human GNLY+CD8+T cells. Pig CD2+CD8+γδT cells were functionally homologous to human CD2+CD4+ γδT cells. Pig CD2−CD8−γδT cells expressed genes with quiescent and precursor characteristics, while CD2−CD8+γδT cells expressed migration and memory-related molecules. Pig CD24+ and CD5+B cells are associated with inflammatory responses. Conclusion Our research with integrated scRNA-seq assays identified the different distribution of pig immune cell subpopulations and the different transcriptional profiles of human and pig immune cells. This study enables a deeper understanding of the development and function of porcine immune cells.