[Effect of influent C/N on nitrogen removal performance in tidal flow constructed wetland via CANON process]. / 进水碳氮比对CANON型人工湿地脱氮性能的影响.

This study was conducted to explore nitrogen transformation and associated microbial characteristics in a tidal flow constructed wetland (TFCW) with the complete autotrophic nitrogen removal over nitrite (CANON) process under influent COD/TN (C/N) constraints. The influent C/N increased from 0.0 to 10.0 via the addition of glucose in the influent as a source of organics. The results showed that influent C/N significantly affected nitrogen transformation rates in the TFCW throughout the experiment. As the influent C/N increased from 0.0 to 6.0, the absolute abundance of functional genes involved in denitrification could be enriched as a consequence of the addition of organics in influent, and then the simultaneous nitrification, anammox, and denitrification (SNAD) processes occurred in the TFCW, resulting in the enhancement of nitrogen removal in the system. However, as the influent C/N was more than 6.0, the activity of aerobic ammonia-oxidizing bacteria was inhibited and its quantity reduced, leading to the deterioration in nitrogen removal of the system. When the influent C/N was 6.0, the SNAD process was enhanced most effectively in the system owing to the development of multiple and complete nitrogen removal pathways in the TFCW. The TFCW respectively had the best TN removal efficiency and removal loading rate [(93.3±2.3)% and (149.30±8.00) mg·L-1·d-1], indicating that the results had been than the maximal TN removal efficiency in a CANON process under ideal conditions.

[Fluid shear stress increases the Ca2+ concentration in bone-marrow derived osteoclast-like cells].

OBJECTIVE: To study the change of Ca2+ density in cultured osteoclast-like cells in response to fluid shear stress. METHODS: Laser scanning confocal microscope and fluorescent probe were used to detect the free Ca2+ in osteoclast-like cells before and after undergoing fluid shear stress. The images were analyzed and compared with image software. RESULTS: At 37 degrees C the free Ca2+ in osteoclast-like cells could be labelled effectively with 10 micromol/L Fluo-3/AM. Compared with contol group, the average intensity of Ca2+ fluorescent signal in osteoclast-like cells undergoing fluid shear stress increased significantly. CONCLUSION: The Cal2+ concentration in bone-marrow derived osteoclast-like cells is sensitive to fluid shear stress, which suggests osteoclast-like cells modulate their function in response to fluid shear stress through the change of free Ca2+ concentration.