Study on compaction mechanism of overconsolidated soil and critical groundwater level in Cangzhou

Cangzhou area is facing increasingly serious land subsidence problem caused by groundwater overexploitation during a long time. In order to make effectively use of water resource and to limit the development of subsidence, it is necessary to establish the warning critical water level, that is, the subsidence rate will increase significantly as the water level depths exceeds the critical groundwater levels. In this paper, the 3rd aquifer group, the main groundwater exploitation layer, has been taken as a research object. The critical water level is calculated by stress analysis, and then determined by the correlation between the monitoring data of groundwater levels and subsidence. The calculated results indicate good consistency

Study on compaction mechanism of overconsolidated soil and critical groundwater level in Cangzhou

Cangzhou area is facing increasingly serious land subsidence problem caused by groundwater overexploitation during a long time. In order to make effectively use of water resource and to limit the development of subsidence, it is necessary to establish the warning critical water level, that is, the subsidence rate will increase significantly as the water level depths exceeds the critical groundwater levels. In this paper, the 3rd aquifer group, the main groundwater exploitation layer, has been taken as a research object. The critical water level is calculated by stress analysis, and then determined by the correlation between the monitoring data of groundwater levels and subsidence. The calculated results indicate good consistency

A study of the critical groundwater level related to soil consolidation characteristics of land subsidence in Cangzhou

Land subsidence has become a serious issue in Cangzhou for a long time. In order to make reasonable use of groundwater resources, it is necessary to establish a warning groundwater level under the premise of controlling the development of land subsidence. How to quantitatively determine the critical gorundwater level (CWL) for comprehensive control of land subsidence? In allusion to this scientific problem, this paper takes the soil samples of three typical settlement areas in Cangzhou as the research object, and analyzes the formation consolidation characteristics. By correlating the stratum thickness, we improve the method of calculating the CWL with the previous consolidation pressure. Based on the monitoring data of land subsidence and groundwater level in Cangzhou for many years, the comprehensive quantitative evaluation of the CWL in Cangzhou are carried out. The results show that the soil within a depth ranging from 0 to 150 m in Cangzhou is normally consolidated or under-consolidated, and the soil below the depth of 150 m is generally over-consolidated. The inelastic water release deformation is an important factor affecting the change of land subsidence rate in this area. Using the improved method, the CWL in Cangzhou, Suning and Dongguang is 66.8 m, 67.5 m and 67.8 m, respectively. Based on the data of the cumulative land subsidence and groundwater level change in the urban of Cangzhou, we obtain the exponential function relationship between the cumulative land subsidence and groundwater level. The subsidence rate is taken as the index, and the critical groundwater level in the urban of Cangzhou ranges from 65 to 70 m. On the basis of verifying the consistency of the calculation results of the two methods, we determined 65 m as the critical groundwater level for the prevention and control measures of land subsidence in Cangzhou. The results provide a reliable basis for the local government to formulate a reasonable groundwater exploitation plan

Roles and mechanisms of leptin in osteogenic stimulation in cervical ossification of the posterior longitudinal ligament

Abstract Background Hyperleptinemia is a common feature of obese people, and leptin, an adipocyte-derived cytokine, is believed to be an important factor in the pathogenesis of cervical ossification of the posterior longitudinal ligament(C-OPLL). So this research was to identify the relation between the serum leptin and bone metabolic markers and how the leptin induced osteogenic effect in C-OPLL. Methods Sixty-four samples were selected to determine the concentration of leptin, insulin, and alkaline phosphatase. And the association of leptin with these factors was also examined. We also evaluate the effect of leptin on the development of C-OPLL and further explored the possible underlying mechanism in vitro. Results We found that serum leptin concentrations were higher in females than in males. Serum leptin and ALP concentrations were increased significantly in C-OPLL females compared to non-OPLL females. In OPLL subjects, the serum leptin concentration corrected for body mass index correlated negatively with the ALP concentrations. In C-OPLL cells, leptin treatment led to a significant increase in mRNA expressions of ALP and OCN and formation of mineralized nodule. Our experiments reported here that osteogenic effect of leptin in C-OPLL cells could be mediated via ERK1/2, p38 MAPK, and/or JNK signaling pathways. Conclusions From this research, we got that leptin treatment led to a significant increase in mRNA expressions of ALP and OCN and formation of mineralized nodule. And the osteogenic effect of leptin in C-OPLL cells could be mediated via ERK1/2, p38 MAPK, and/or JNK signaling pathways

Influence of Pedestal Fiber Splice on Tm-Doped Fiber Laser Performance

The influence of Tm-doped pedestal fiber splice on the output performance of a large-mode-area (LMA) Tm-doped fiber laser (TDFL) has been investigated. Arc-fusion induced refractive-index deformation leads to laser leakage from the core to the pedestal, resulting in a periodic decrease in the output power of TDFL. Based on the measured refractive-index of splice with different arc-fusion parameters, the influence of the Tm-doped pedestal splice on laser propagation was analyzed using the beam propagation method (BPM). The simulation results indicate that optimizing the arc-fusion parameters can improve the efficiency of laser coupling into the fiber core at the splice. Experimental comparisons were made to assess the impact of different arc-fusion parameters on laser performance. By optimizing arc-fusion parameters of the TDFL, the near-periodic power degradation is reduced effectively. A hundred-watt-level all-fiber TDF setup was established. Compared to the initial splice, the optical conversion efficiency increased from 39.6% to 48.4% and the beam quality factor M2 was reduced from 10.55 to 2.17 in the horizontal direction and from 11.89 to 2.26 in the vertical direction. Understanding these mechanisms behind the abnormal power fluctuations hold practical value for the design of TDF pedestal fiber and further power scaling

Role of Establishing General Surgery Emergency Surgical Team in Improving the Work Efficiency of Emergency Surgery

Objective  To explore the role of establishing general surgical emergency team in improving the efficiency of emergency surgical treatment.  Methods  All patients attending emergency surgery from August1, 2019 to July 31, 2021 were retrospectively analysed. The number of flow, observation and their ratio before and after the establishment of general surgical emergency team were compared. The clinical data, including age, gender, complication, diagnoses, the number of surgery, the grading of disease, preoperative preparation time, the ratio of transfer to ICU, the ratio of patients staying more than 30 days, and complication rate before and after the establishment were analysed. Length of stay and hospitalization costs were compared by surgical grading and disease severity grading. The factors affecting hospitalization costs in emergency surgery patients were analysed using univariate and multiple linear regression.  Results  A total of 37 945 flow patients were included. Before and after the establishment of the surgical team, the number of flow was 15 745 and 22 200, respectively (1312 and 1850 monthly), the number of observation was 1814 and 1622, respectively (151 and 135 monthly), and the ratio of observation to flow decreased from 11.6% to 7.3% (P=0.000), preoperative preparation time decreased from (1.5±0.7) days to (0.7±0.9) days (P=0.000), the ratio of transfer to ICU decreased from 37.9% to 23.7% (P=0.000), the ratio of patients staying more than 30 days decreased from 5.7% to 0.5% (P=0.000), the average length of stay (5 d vs. 3 d, P=0.028) and cost (34 000 vs. 13 000, P=0.000) were significantly reduced, and the total operation number were 317 and 919, respectively(26 vs. 77 monthly, P=0.000).There was no significant change in complication rate (P=0.548). Multiple linear regression showed that establishing emergency surgery team reduced the hospitalization cost, while high surgical grading, long hospitalization time and transfer to ICU increased the hospitalization cost.  Conclusion  The establishment of emergency surgery team can solve the current problem of emergency to some degree, such as evacuating emergency congestion, increasing emergency surgery turnover rate, reducing the medical burden, and improving the efficiency of emergency treatment