Investigation of preoperative physical activity level in kidney transplant recipients and its impact on early postoperative recovery: A retrospective cohort study.

Objective: To retrospectively investigate the preoperative physical activity (PA) level in kidney transplant recipients (KTRs) and its impact on early postoperative recovery. Methods: A total of 113 patients who received kidney transplantation at West China Hospital of Sichuan University were enrolled in this retrospective cohort study. According to the PA level measured by the Chinese version of the International Physical Activity Questionnaire-Long Version, the patients were allocated into the low PA level group (Group L, n = 55) and medium to high PA level group (Group MH, n = 58). The kidney function recovery indicators, including estimated glomerular filtration rate (eGFR), postoperative complications, postoperative length of stay (LOS), and unscheduled readmission within three months of discharge, were evaluated and documented. A association analysis was applied to analyze and compare the association between indicators. Results: The median PA levels of the KTRs were 1701.0 MTEs * min/week. Regarding the postoperative recovery indicators, the KTRs spent a mean time of 19.63 h to achieve transfer out of bed after the operation (Group L: 19.67 h; Group MH: 19.53 h; P = 0.952) and reached a mean distance of 183.10 m as the best ambulatory training score within two days after the operation (Group L: 134.91 m; Group MH: 228.79 m; P < 0.001). The preoperative PA level showed a moderate positive association with early postoperative ambulation distance (ρ = 0.497, P < 0.001). However, no significant between-group difference in eGFR on postoperative days 1, 3, and 5 (P = 0.913, 0.335, and 0.524) or postoperative complications, including DGF (P = 0.436), infection (P = 0.479), postoperative LOS (P = 0.103), and unscheduled readmission (P = 0.698), was found. Conclusions: The preoperative PA level of KTRs is lower than that of the general population. KTRs with moderate or high preoperative PA levels showed higher ambulatory function in the early postoperative period than those with low preoperative PA levels, but no between-group differences in other early recovery indicators were observed.

[Effects of Wastewater Nitrogen Concentrations and NH4+/NO3- on Nitrogen Removal Ability and the Nitrogen Component of Myriophyllum aquaticum (Vell.) Verdc].

Solution culture experiments were conducted to investigate the effect of wastewater nitrogen levels and NH4+/NO3- on nitrogen removal ability and the nitrogen component of Myriophyllum aquaticum. Experiments with three nitrogen levels and NH4+/NO3- were set up as follows:20, 100, and 200 mg·L-1and NH4+/NO3- 1:0, 0.5:0.5, and 0:1. The results showed that the biomass of plants increased fastest during the first week. The plants treated with NH4+/NO3-=1:0 with nitrogen levels of 20 and 100 mg·L-1 and those treated with NH4+/NO3-=0.5:0.5 with a nitrogen concentration of 200 mg·L-1 exhibited higher biomass than the others. The removal rates of water total nitrogen, ammonium nitrogen, and nitrate nitrogen during the first week were the maximum for all treatments and increased with water nitrogen levels. There were no significant differences in the removal rate between ammonium nitrogen and nitrate nitrogen with a nitrogen level of 20 mg/L, while with nitrogen levels of 100 and 200 mg·L-1, the nitrate removal rates were higher than those for ammonium nitrogen. The Myriophyllum aquaticum nitrogen accumulation and its contribution rate to nitrogen removal from water and sediment were all increased with water nitrogen levels and increased fastest during the first week. The contribution rate of nitrogen accumulated by plants with NH4+/NO3-=0:1 was the highest with nitrogen levels of 20 mg·L-1, while plants with NH4+/NO3-=0.5:0.5 were the highest with nitrogen levels of 100 and 200 mg·L-1. The protein, amino, and nitrate nitrogen contents in Myriophyllum aquaticum plants were all increased by increasing water nitrogen levels with a ranking of protein content > amino nitrogen content > nitrate nitrogen content. The protein concentrations in plants with NH4+/NO3-=1:0 and NH4+/NO3-=0.5:0.5 were higher regardless of water nitrogen levels, while the amino nitrogen concentration in plants with NH4+/NO3-=1:0 and the nitrate nitrogen content in plants with NH4+/NO3-=0:1 were higher than the others. It was concluded that the nitrogen removal ability of Myriophyllum aquaticum was improved by raising water nitrogen levels under the tested condition, which indicates that Myriophyllum aquaticum could purify high nitrogen wastewater. Myriophyllum aquaticum is an ammonium-nitrophile, but had the strongest capacity for growing and removing wastewater nitrogen exhibited with higher than 100 mg·L-1 nitrogen levels only with equal NH4+ to NO3-. The nitrogen component concentrations of protein, amino, and nitrate in Myriophyllum aquaticum plant were all affected by the ratio of NH4+/NO3-.

Uptake, transport and distribution of molybdenum in two oilseed rape (Brassica napus L.) cultivars under different nitrate/ammonium ratios.

OBJECTIVES: To investigate the effects of different nitrate sources on the uptake, transport, and distribution of molybdenum (Mo) between two oilseed rape (Brassica napus L.) cultivars, L0917 and ZS11. METHODS: A hydroponic culture experiment was conducted with four nitrate/ammonium (NO3-:NH4+) ratios (14:1, 9:6, 7.5:7.5, and 1:14) at a constant nitrogen concentration of 15 mmol/L. We examined Mo concentrations in roots, shoots, xylem and phloem sap, and subcellular fractions of leaves to contrast Mo uptake, transport, and subcellular distribution between ZS11 and L0917. RESULTS: Both the cultivars showed maximum biomass and Mo accumulation at the 7.5:7.5 ratio of NO3-:NH4+ while those were decreased by the 14:1 and 1:14 treatments. However, the percentages of root Mo (14.8% and 15.0% for L0917 and ZS11, respectively) were low under the 7.5:7.5 treatment, suggesting that the equal NO3-:NH4+ ratio promoted Mo transportation from root to shoot. The xylem sap Mo concentration and phloem sap Mo accumulation of L0917 were lower than those of ZS11 under the 1:14 treatment, which suggests that higher NO3-:NH4+ ratio was more beneficial for L0917. On the contrary, a lower NO3-:NH4+ ratio was more beneficial for ZS11 to transport and remobilize Mo. Furthermore, the Mo concentrations of both the cultivars' leaf organelles were increased but the Mo accumulations of the cell wall and soluble fraction were reduced significantly under the 14:1 treatment, meaning that more Mo was accumulated in organelles under the highest NO3-:NH4+ ratio. CONCLUSIONS: This investigation demonstrated that the capacities of Mo absorption, transportation and subcellular distribution play an important role in genotype-dependent differences in Mo accumulation under low or high NO3-:NH4+ ratio conditions.

[Effect of Wastewater Nitrogen Concentrations on Nitrogen Removal Ability of Myriophyllum aquaticum].

Myriophyllum aquaticum, which is an important plant for constructed wetlands, has powerful purification ability for wastewater, however, the relationship between nitrogen removal ability of Myriophyllum aquaticum and wastewater nitrogen concentrations is still unclear. In this study, pot culture experiment was conducted to investigate the effect of wastewater nitrogen levels on nitrogen removal ability of Myriophyllum aquaticum. 7 nitrogen levels were set up as following:2, 5, 10, 20, 100, 200, 400 mg·L-1. The results showed that when the wastewater nitrogen concentration was not higher than 20 mg·L-1, Myriophyllum aquaticum with 20 mg·L-1 of nitrogen concentration grew best in the first 3 weeks; the removal rates of total and ammonia nitrogen were nearly 100% after one week, while the nitrate nitrogen concentrations were very low and varied little; the nitrogen contents of Myriophyllum aquaticum had no significant change, the upper part nitrogen content was higher than the underneath, Myriophyllum aquaticum could also remove nitrogen from the sediment. When wastewater nitrogen concentrations were 100-400 mg·L-1, Myriophyllum aquaticum with 200 mg·L-1 of nitrogen concentration grew best from 4th to 5th week; the removal rates of total nitrogen were 76.5%, 71.5% and 48.1% in the three treatments, and the removal rates of ammonia nitrogen were 99.6%, 99.3% and 60.2% respectively, while the removal rates of nitrate nitrogen were all about 50% and there was no significant difference among treatments; the nitrogen contents of Myriophyllum aquaticum increased with nitrogen levels, but the difference between upper part and underneath was not remarkable, showing uniform distribution; nitrogen accumulations by Myriophyllum aquaticum and sediment accounted for 27.9%-48.4% and 12.2%-24.4% of total nitrogen loss in wastewater. Therefore, the nitrogen removal ability of Myriophyllum aquaticum should be inhibited by higher wastewater nitrogen level, the ammonia nitrogen removal rate was significantly higher than nitrate, the mechanism of Myriophyllum aquaticum nitrogen accumulation and distribution should also be affected by wastewater nitrogen level, and further research is needed.

[Mitigation of nitrous oxide emissions in vegetable system by treating soil with dicyandiamide, a nitrification inhibitor].

Undisturbed soil monolith lysimeter was used to investigate the effectiveness of DCD (dicyandiamide) in reducing N2O emissions in vegetable (Chinese cabbage and pepper) field. Results showed that DCD significantly reduced total N2O emission in vegetable field. Total N2O emissions from the urea treatment without DCD reached 0.215 kg x hm(-2) for Chinese cabbage, and it reduced to 0.109 kg x hm(-2), equivalent to a 49.3% reduction. The total N2O emissions for pepper were much higher compared with those for Chinese cabbage. The total N2O emitted from the urea treatment was 2.32 kg x hm(-2) (without DCD) and it was reduced to 1.14 kg x hm(-2) with DCD application, representing a 50.9% reduction. In the control treatments where no urea was applied, the daily N2O flux was very low and it never exceeded 9 microg x (m2 x h) (-1) for Chinese cabbage and 22 microg x (m2 x h) (-1) for pepper, respectively, but DCD also reduced N2O emissions (33.5% for Chinese cabbage and 33.4% for pepper). In addition, the urea-N emission factor (EF) was 0.15%, 0.99% for Chinese cabbage and pepper without DCD, respectively, and it was reduced to 0.07%, 0.52% when DCD was applied. These results demonstrated the potential of using nitrification inhibitors (DCD) to mitigate N2O emissions in vegetable system.

Effects of molybdenum on antioxidative defense system and membrane lipid peroxidation in winter wheat under low temperature stress.

Effects of molybdenum (Mo) on antioxidative defense system and membrane lipid peroxidation in leaves of winter wheat (Triticum aestivum H. var. Huamai 8) were investigated under low temperature stress. Results of experiments indicate that Mo application in winter wheat induced a dramatic decrease in electrolyte leakage and malondialdehyde content under low temperature stress. The activities of antioxidative enzymes such as superoxide dismutase (SOD, EC 1.15.1.1), peroxidase (POX, EC 1.11.1.7) and catalase (CAT, EC 1.11.1.6) were increased by Mo application and the extents of increase at low temperature were higher than those at normal temperature. Mo application also caused a significant increase in the ascorbic acid (AsA) and proline contents both at normal and low temperature and following the low temperature stress the increases in ascorbic acid and proline contents in Mo-treated winter wheat were higher. There was no significant difference in carotenoid (CAR) content between with and without Mo treatment under normal temperature, while there was a significant increase in Mo treatment under low temperature stress. It could be speculated that Mo application enhanced cold resistance by increasing the capacity to scavenge active oxygen species and alleviating membrane damage in winter wheat under low temperature stress.