This study evaluates improvement of the acetabular index (AI) in patients with developmental dysplasia of the hip at 4 years after closed reduction, and determines the association between the final AI and a set of factors. Sixty-two patients (74 hips) treated with closed reduction were categorized into three groups according to age: group A (0-12 months, 18 hips), group B (13-18 months, 24 hips), and group C (>18 months, 32 hips). There was no difference in AI among the three groups before reduction (P=0.293). In groups A and C, the AI decreased significantly over time until 3 years after reduction and no differences were observed between the time points of 3 and 4 years. At 4 years after reduction, the AI of group C was significantly higher than that of groups A (P<0.001) and B (P=0.012). The overall AI improvement rate was 28.63%. The AI improvement rate of group A was significantly higher than that of group C (P=0.005). Pearson correlation analysis indicated no correlation between center-head distance discrepancy and the final AI (P=0.811). Linear regression suggested that age and initial AI correlated significantly with the final AI (R=0.617, F=15.031, P<0.001). Other factors, such as sex, center-edge angle of Wiberg, bilaterally involved, and avascular necrosis of the femoral head, showed no correlations with the final AI (P>0.05). According to the coefficients, initial AI (β1=0.432, P<0.001) had greater effect than age (β2=0.197, P=0.023) on the final AI. In conclusion, the AI decreases in all patients after reduction and stabilizes at 3 years after reduction. The AI improvement rate is correlated negatively with age. Age and initial AI are early predictors of the progress of AI after closed reduction in developmental dysplasia of the hip patients.

Background Salinization damages the health of soil systems and reduces crop yields. Responses of microbial communities to salinized soils and their functional maintenance under high salt stress are valuable scientific problems. Meanwhile, the microbial community of the salinized soil in the plateau environment is less understood. Here, we applied metagenomics technology to reveal the structure and function of microorganisms in salinized soil of the Tibetan Plateau. Results The diversity of composition and function of microbial community in saline soil have changed significantly. The abundances of chemoautotrophic and acidophilic bacteria comprising Rhodanobacter, Acidobacterium, Candidatus Nitrosotalea, and Candidatus Koribacter were significantly higher in saline soil. The potential degradation of organic carbon in the saline soil, as well as the production of NO and N2O via denitrification, and the production of sulfate by sulfur oxidation were significantly higher than the non-saline soil. Both types of soils were rich in genes encoding resistance to environmental stresses (i.e., cold, ultraviolet light, and hypoxia in Tibetan Plateau). The resistance of the soil microbial communities to the saline environment is based on the absorption of K+ as the main mechanism, with cross-protection proteins and absorption buffer molecules as auxiliary mechanisms in our study area. Network analysis showed that functional group comprising chemoautotrophic and acidophilic bacteria had significant positive correlations with electrical conductivity and total sulfur, and significant negative correlations with the total organic carbon, pH, and available nitrogen. The soil moisture, pH, and electrical conductivity are likely to affect the bacterial carbon, nitrogen, and sulfur cycles. Conclusions These results indicate that the specific environment of the Tibetan Plateau and salinization jointly shape the structure and function of the soil bacterial community, and that the bacterial communities respond to complex and harsh living conditions. In addition, environmental feedback probably exacerbates greenhouse gas emissions and accelerates the reduction in the soil pH. This study will provide insights into the microbial responses to soil salinization and the potential ecological risks in the special plateau environment.

The conglomerate reservoir is provided with strong heterogeneity and complex pore structure. To study the matching relationship between polymer flooding system and pore throat of the conglomerate reservoir and set up the flow matching relationship plate, this paper conducted natural core flow experiments at the true flow rate of the site formation based on constant pressure flooding method, considering the shear of the borehole and the formation. And several suitable polymers for different reservoirs permeability were given. The experimental results indicated that a positive correlation between the flow properties and the viscosity of the polymer solution, but a negative correlation between the mobility and the permeability of reservoir. Such as the natural core with the permeability = 30×10-3μm2 was suitable for the viscosity≤16.0 mPa.s of the polymer solution in the formation, the natural core with the permeability = 60×10-3μm2 was suitable for the viscosity≤35.2mPa.s of the polymer solution and the natural core with the permeability = 120×10-3μm2 was suitable for the viscosity≤102.4mPa.s of the polymer solution. Using compatibility relationship, quickly and easily choose the right injection parameters of the polymer based on the reservoir permeability, providing a theoretical basis for program preparation and parameters adjustment of the polymer flooding.

In this paper, the high concentration polymer oil flooding experiments were first carried out on two artificial cores that with different Permeability (1000×10-3μm2 and 1700×10-3μm2) by using various concentrations of the polymer respectively(2000mg/L, 3000mg/L, 4000mg/L, 5000mg/L).The relationship between the polymer concentration and oil recovery was given, the upper limit of the polymer concentration was obtained according to the oil displacement efficiency, and the feasibility of the polymer concentration upper limit was investigated. Then it was found that higher produced water polymer concentrations were needed if the same the oil displacement efficiency was reached compared those fresh water polymer solutions by comparing the oil displacement efficiency that using produced water polymer solutions and fresh water polymer solutions.

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