Research on soil net nitrogen mineralization in Stipa grandis grassland with different stages of degradation

Wanyu Wen,Xiaobing Li,Lihong Chen,Dandan Wei,Han Wang,Meng Zhang,Jing Yu 한국지질과학협의회 2016 Geosciences Journal Vol.20 No.4

Net nitrogen mineralization is one of the nitrogen cycling process, and it is very important to understand nitrogen mineralization characteristics in degradation grassland. In the upper 0–10 cm soil layer of Stipa grandis P. A. Smirn. grassland in the Xilin river basin, Inner Mongolia, we studied the soil net nitrogen mineralization and nitrification among three varying stages of degradation grassland and analyzed the relationship between the mineralization rate of the soil net nitrogen and environmental factors, using the resin-core incubation method. Our results demonstrated that, from May to October 2012, the accumulated net nitrogen mineralization was 21.620 mg kg–1, 12.486 mg kg–1, and 48.053 mg kg–1 in the slightly, medium, and heavily degraded grasslands, respectively and varied greatly among the three stages of degradation shown by the S. grandis grassland plots. During the cultivation period, the variation of net nitrogen mineralization and nitrification was similar to the variation of soil mineral nitrogen. The higher soil mineral nitrogen content indicated higher mineralization of net nitrogen. In July and August, soil moisture was positively correlated with the net nitrogen mineralization rate, and the correlation coefficients between these two factors of 0.73, 0.58, and 0.79 for the slightly, medium, and heavily degraded plots, respectively. The rates of net nitrogen mineralization and nitrification were negatively correlated with soil total nitrogen, but positively correlated with C/N ratio, and weakly correlated with other physicochemical properties.

Experimental Study on the Damage of Steel Tubular Structural Components by Near-Field Detonations

Wanyue Wang,Shaobo Geng,Hua Wang,Wenqiang Li,Yaling Liu,Jianying Xue,Tingbian Zhan,Ying Gao 대한토목학회 2021 KSCE Journal of Civil Engineering Vol.25 No.2

This paper describes three blast-loading trials on three kinds of steel tubular structural components at the same explosive charge and standoff distance. Specimen one is a hollowsteel tube (HST), another is a HST wrapped with glass fibre-reinforced plastic (GFRP) with epoxy resin and the third is a HST infilled with concrete. The main objective of the trials is to investigate the effect of near-field detonations on circular steel tubular components. The experimental data, such as the overpressure time history, front local deformation, rear residual deflection and strain time history, are all recorded and collected. Analysis of the trial results shows that the experimental peak overpressure values of shot 1-3 are all larger than that of numerical simulation. The failure of these three specimens mainly experiences local damage, at the same time, the HST and HST with GFRP exhibit obvious global deformation. With the initiation point at one end of the cylinder explosive, both the maximum depth deformation on the front surface and the maximum residual deflection on the rear surface are all located on the side of the another end of the cylinder explosive. The blast-resistant approach by covering 10-layer GFRP on the surface of the HST can reduce the local damage, the global deformationand the dynamic strain value to certain extent, while the approach by infilling the steel tube with concrete can greatly decrease the local damage and the dynamic strain value and without any global deformation.

IL-17A Secreted by Th17 Cells Is Essential for the Host against Streptococcus agalactiae Infections

( Jing Chen ),( Siyu Yang ),( Wanyu Li ),( Wei Yu ),( Zhaowei Fan ),( Mengyao Wang ),( Zhenyue Feng ),( Chunyu Tong ),( Baifen Song ),( Jinzhu Ma ),( Yudong Cui ) 한국미생물생명공학회(구 한국산업미생물학회) 2021 Journal of microbiology and biotechnology Vol.31 No.5

Streptococcus agalactiae is an important bacterial pathogen and causative agent of diseases including neonatal sepsis and meningitis, as well as infections in healthy adults and pregnant women. Although antibiotic treatments effectively relieve symptoms, the emergence and transmission of multidrug-resistant strains indicate the need for an effective immunotherapy. Effector T helper (Th) 17 cells are a relatively newly discovered subpopulation of helper CD4⁺ T lymphocytes, and which, by expressing interleukin (IL)-17A, play crucial roles in host defenses against a variety of pathogens, including bacteria and viruses. However, whether S. agalactiae infection can induce the differentiation of CD4⁺ T cells into Th17 cells, and whether IL-17A can play an effective role against S. agalactiae infections, are still unclear. In this study, we analyzed the responses of CD4⁺ T cells and their defensive effects after S. agalactiae infection. The results showed that S. agalactiae infection induces not only the formation of Th1 cells expressing interferon (IFN)-γ, but also the differentiation of mouse splenic CD4⁺ T cells into Th17 cells, which highly express IL-17A. In addition, the bacterial load of S. agalactiae was significantly increased and decreased in organs as determined by antibody neutralization and IL-17A addition experiments, respectively. The results confirmed that IL-17A is required by the host to defend against S. agalactiae and that it plays an important role in effectively eliminating S. agalactiae. Our findings therefore prompt us to adopt effective methods to regulate the expression of IL-17A as a potent strategy for the prevention and treatment of S. agalactiae infection.

A Novel Method of Self-Healing in Cementitious Materials by Using Polyacrylic Hydrogel

Bo Zhu,Qiu Li,Wei Chen,Wei Zou,Wanyu Chen 대한토목학회 2020 KSCE JOURNAL OF CIVIL ENGINEERING Vol.24 No.11

Cementitious materials are the most widely used in the construction. However, cementitious materials have defects such as low tensile strength which is easy to cause the formation of cracks. In recent years, with the research and application of smart materials, intelligent cementitious materials with self-sensing, self-diagnosis and self-healing functions have received extensive researcher’s attention. In this paper, a polyacrylic hydrogel that could be utilized for self-healing of cementitious materials was designed, and the three-dimensional network structure of the hydrogel controlled the release rate of encapsulated repair agent. The phosphate-incorporated hydrogel was filled into cement slurry to prepare self-healing cementitious materials. After the cement sample cracked and water penetrated into the crack, the phosphate was released from hydrogel. Phosphate reacted with the calcium in the pore solution to form hydroxyapatite type minerals which healed the crack. The self-healing cementitious material is in a position to heal cracks of 300 μm in width. After healing for 28 days at 20oC and 95% of RH, the compressive strength of precracked specimens could reach 85% of that of intact ones.

IL28B Is Associated with Outcomes of Chronic HBV Infection

Xiaodong Shi,Junqi Niu,Xiumei Chi,Yu Pan,Yanhang Gao,Wanyu Li,Chen Yang,Jin Zhong,Damo Xu,Manna Zhang,Gerald Minuk,Jing Jiang 연세대학교의과대학 2015 Yonsei medical journal Vol.56 No.3

Purpose: The role of IL28B gene variants and expression in hepatitis B virus (HBV) infections are not well understood. Here, we evaluated whether IL28B gene expression and rs12979860 variations are associated with HBV outcomes. Materialsand Methods: IL28B genetic variations (rs12979860) were genotyped by pyrosequencingof DNA samples from 137 individuals with chronic HBV infection [50 inactive carriers (IC), 34 chronic hepatitis B (CHB), 27 cirrhosis, 26 hepatocellular carcinoma (HCC)], and 19 healthy controls. IL28A/B mRNA expression in peripheralblood mononuclear cells was determined by qRT-PCR, and serum IL28B proteinwas measured by ELISA. Results: Patients with IL28B C/C genotype had greater IL28A/B mRNA expression and higher IL28B protein levels than C/T patients. Within the various disease stages, compared to IC and healthy controls, IL28B expression was reduced in the CHB, cirrhosis, and HCC cohorts (CHB vs. IC, p=0.02; cirrhosis vs. IC, p=0.01; HCC vs. IC, p=0.001; CHB vs. controls, p<0.01; cirrhosis vs. controls, p<0.01; HCC vs. controls, p<0.01). When stratified with respect to serum HBV markers in the IC and CHB cohorts, IL28B mRNA and protein levels were higher in HBeAg-positive than negative individuals (p=0.01). Logistic regression analysis revealed that factors associated with high IL28B proteinlevels were C/C versus C/T genotype [p=0.016, odds ratio (OR)=0.25, 95% confidence interval (CI)=0.08‒0.78], high alanine aminotransferase values (p<0.001, OR=8.02, 95% CI=2.64‒24.4), and the IC stage of HBV infection (p<0.001). Conclusion: Our data suggest that IL28B genetic variations may play an important role in long-term development of disease in chronic HBV infections.