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In-situ leaching of uranium is the most predominant method for the current exploitation of sandstone-type uranium deposits. The focus of in-situ leaching of uranium deposits lies in enhancing extraction capacity, and leaching rate, and reducing extraction costs. In order to improve leaching efficiency and reduce costs, the optimization experiments and research on the filter, acidity, and pumping volume were carried out at a uranium in-situ leaching deposit in Inner Mongolia. The research showed that maintaining the length of the filter could be controlled within 4-6 m to ensure its high efficiency and the connection between the upper section of the filter and the rich ore-bearing block with relatively high grade was conducive to the improvement of uranium leaching rate. The leaching efficiency and concentration of uranium in the leaching solution could be improved by controlling the acidity of the solution at about 15 g/L. The pumping volume(single width) was maintained at 0. 75-1.0 mz/h, so that the mining area could maintain a high uranium extraction capacity and a low leaching volume. Through the optimized technical parameters, the optimized peak uranium concentration in the leaching solution was increased from 28.89 mg/L to 59. 72 mg/L. During the initial two years of operation in the mining area, the uranium leaching rate increased from 47.20% to 60. 99%, the average uranium concentration in the leaching solution increased from 17.43 mg/L to 32. 63 mg/L, the acid consumption per ton of uranium decreased by 15. 26%,and the electricity consumption per ton of uranium decreased by 46. 51%. The research had changed the previous "large flow, low concentration" leaching mode, achieving efficient optimization of uranium extraction technology by in-situ leaching. [ABSTRACT FROM AUTHOR]

Uranium extraction by ground leaching is the main mining method for sandstone-type uranium mines, and not only is uranium dissolved after the acidic leach solution reacts with the ore, but a large number of impurity ions are also transferred into the leach solution. This paper takes a pumping unit in the northern part of the C12 mining area of Bayan Wula uranium mine as the research object and carries out systematic research on the evolution characteristics of the chemical composition of leach solution by monitoring the chemical composition of leach solution from its pumping holes. The results show that the increase in ion concentration of leach solution is the result of the interaction between the high acid leach solution and the minerals in the ore-bearing layer, and the evolution of ion concentration goes through three stages, namely, rising, rapidly rising and relatively stable, and the higher the acidity, the faster the rate of increase in concentration, and the order of the reaction between minerals and sulphuric acid is roughly as follows; carbonate, pyrite(iron oxides), silica-alumina, sodium feldspar, and potassium feldspar; the growth rate of the concentration of the cations concerned is similar to the growth rate of SO42- concentration. SO42+ concentration growth rate evolution characteristics have synchronization, SO42- concentration of more than 12 g/L Ca2+ concentration appeared to decrease, indicating that the precipitation of CaSO4 occurred. These research results have important theoretical significance and high academic value for indicating the evolution of mineral dissolution and migration. [ABSTRACT FROM AUTHOR]

In the process of ground leaching uranium aching, permeability is the important factor that determining the leaching efficiency, and maintaining good permeability plays an important role in uranium leaching. At present, the blockage of the mineral layer scale reduces the mineral layer permeability and affects the leaching efficiency is the general problems existing in the operation of immersed mines. Based on the hydrogeological conditions of Naling ditch naluranium deposit and the generating mechanism of main sediment in CO2 + O2 underground uranium extraction test, to address the reducing permeability of the ore layer, by analyzing the type and characteristics of the sediment during the leaching process, to explore the main reasons of sediment generation and blockage of mineral layer, proposing to add CO2 for micro-acid pre-acidification within 20 to 30 days before the mining is operation until the HCO3-ion concentration is maintained at 1 000 mg/L, and adjust the environment of immersion channel, keep the main sediment at high solubility; Then inject oxygen for oxidation, and regulate the residual oxygen content at about 20 mg/L; Moreover, instead the current bag filtration method, the technical measures, such as the centralized filtration method, such as activated carbon, quartz sand, and cationic resin, removing the harmful metal ions from the dissolved solution effectively, reducing the formation of secondary precipitation in reinjection layer was used in the study, to control the generation and accumulation of sediment in the soluble immersion channel effectively, thus realize the efficient leaching operation of ground-dip uranium mines. [ABSTRACT FROM AUTHOR]

Objective: To investigate the target blood pressure level of restrictive fluid resuscitation in patients with traumatic hemorrhagic shock., Methods: Sixty patients with traumatic hemorrhagic shock admitted to the First Affiliated Hospital of Bengbu Medical College from January 2016 to December 2018 were enrolled. All patients were resuscitated with sodium acetate ringer solution after admission. According to the difference of mean arterial pressure (MAP) target, the patients were divided into low MAP (60 mmHg ≤ MAP < 65 mmHg, 1 mmHg = 0.133 kPa), middle MAP (65 mmHg ≤ MAP < 70 mmHg) and high MAP (70 mmHg ≤ MAP < 75 mmHg) groups by random number table using the admission order with 20 patients in each group. Those who failed to reach the target MAP after 30-minute resuscitation were excluded and supplementary cases were deferred. The restrictive fluid resuscitation phase was divided into three phases: before fluid resuscitation, liquid resuscitation for 30 minutes and 60 minutes. The most suitable resuscitation blood pressure level was further speculated by monitoring the inflammatory markers and hemodynamics in different periods in each group of patients. Pearson correlation analysis was used to detect the correlation of variables., Results: Before fluid resuscitation, there was no significant difference in hemodynamics or expressions of serum cytokines among the three groups. Three groups of patients were resuscitated for 30 minutes to achieve the target blood pressure level and maintain 30 minutes. With the prolongation of fluid resuscitation time, the central venous pressure (CVP), cardiac output (CO) and cardiac index (CI) were increased slowly in the three groups, and reached a steady state at about 30 minutes after resuscitation, especially in the high MAP group and the middle MAP group. The expressions of serum inflammatory factors in the three groups were gradually increased with the prolongation of fluid resuscitation time. Compared with the low MAP group and the high MAP group, after 30 minutes of resuscitation the middle MAP group was superior to the other two groups in inhibiting the expressions of pro-inflammatory factors tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and promoting anti-inflammatory factors IL-10 [TNF-α mRNA (2 -ΔΔCt ): 0.21±0.13 vs. 0.69±0.34, 0.57±0.35; IL-6 mRNA (2 -ΔΔCt ): 0.35±0.31 vs. 0.72±0.39, 0.59±0.42; IL-10 mRNA (2 -ΔΔCt ): 1.25±0.81 vs. 0.61±0.46, 0.82±0.53; all P < 0.05], but there was no significant difference in promoting the expression of IL-4 mRNA among three groups. At 60 minutes of resuscitation, compared with the low MAP group and the high MAP group, the middle MAP group could significantly inhibit the expressions of TNF-α, IL-6 and promote IL-10 [TNF-α mRNA (2 -ΔΔCt ): 0.72±0.35 vs. 1.05±0.54, 1.03±0.49; IL-6 mRNA (2 -ΔΔCt ): 0.57±0.50 vs. 1.27±0.72, 1.01±0.64; IL-10 mRNA (2 -ΔΔCt ): 1.41±0.90 vs. 0.81±0.48, 0.94±0.61; all P < 0.05]. Compared with the high MAP group, the middle MAP group had significant differences in promoting the expression of IL-4 mRNA (2 -ΔΔCt : 1.32±0.62 vs. 0.91±0.60, P < 0.05). There was no significant difference in serum cytokine expressions at different time points of resuscitation between the low MAP group and the high MAP group (all P > 0.05). Correlation analysis showed that there was a strong linear correlation between MAP and mRNA expressions of TNF-α, IL-6, IL-10 in the middle MAP group (r value was 0.766, 0.719, 0.692, respectively, all P < 0.01), but had no correlation with IL-4 (r = 0.361, P = 0.059). Fitting linear regression analysis showed an increase in 1 mmHg per MAP, the expression of TNF-α mRNA increased by 0.027 [95% confidence interval (95%CI) = 0.023-0.031, P < 0.001], IL-6 mRNA increased by 0.021 (95%CI = 0.017-0.024, P < 0.001), and IL-10 mRNA increased by 0.049 (95%CI = 0.041-0.058, P < 0.001)., Conclusions: When patients with traumatic hemorrhagic shock received restrict fluid resuscitation at MAP of 65-70 mmHg, the effect of reducing systemic inflammatory response and improving hemodynamics is better than the target MAP at 60-65 mmHg or 70-75 mmHg. It is suggested that 65-70 mmHg may be an ideal target MAP level for restrictive fluid resuscitation.

Objective: From the previous comparative genomic analysis, we found a specific unknown 10 kb sequence (including 11 Open reading Frames) in Chinese piscine strain GD201008-001 genome. To study the role of 10 kb in the pathogenicity of piscine S. agalactiae, the 10 kb sequence was deleted from the GD201008-001 genome., Methods: The isogenic mutant Δ10 kb was constructed by using the temperature-sensitive Streptococcus-E. coli shuttle vector pSET4s. We compared the growth characteristics, adherence to HEp-2 cell and bacterial virulence in a zebrafish infection model between wild strain and mutant. Meanwhile the expressions of the known virulence genes from GD201008-001 and Δ10 kb were also quantified by real-time PCR., Results: The Δ10 kb showed no significant differences in bacterial morphology and adherence to HEp-2 cells compared with the wild-type strain, but the speed of growth was slightly slower than the wild strain. Furthermore the 50% lethal dose of Δ10 kb was decreased up to 10-fold (P < 0.001) of the parental strain in a zebrafish infection model, and the expressions of the virulence genes, PI-2b and neul, were significantly increased in the mutant., Conclusion: These findings demonstrated that the 10 kb sequence of piscine Streptococcus agalactiae exerts a significant effect on bacterial virulence and probably regulates the virulence genes expression of GD20 1008-001.

With pot experiment, this paper studied the membrane lipid peroxidation and the variations of antioxidation system in Cynodon dactylon under recirculated landfill leachate irrigation. The results showed that when irrigated with low dilution ratio (< 25%) leachate, the chlorophyll a/b ratio increased with increasing dilution ratio, membrane permeability and MDA and H2O2 contents were in adverse, and membrane lipid peroxidation was relatively weak. However, with the increasing leachate dilution ratio (> 25%), there existed an obvious negative fect on Cynodon dactylon, i.e., the chlorophyll a/b ratio decreased, while cell membrane permeability and MDA and H2O2 contents increased, which meant that the membrane lipid peroxidation was accelerated. The contents antioxidants AsA, GSH and Car also showed the similar trend, i.e., they increased with increasing leachate dilution ratio when irrigated with low dilution ratio leachate, but decreased under medium or high dilution ratio leachate irrigation. Among three test anti-oxidative enzymes, SOD and POD activities showed a similar change test antioxidants, and POD activity was more sensitive, while CAT activity was on the contrary. The contents test antioxidants and the activities of SOD and POD were negatively and significantly correlated to MDA content, indicating that they might play an important role in preventing Cynodon dactylon from cell membrane lipid peroxdation.