The aim of this research is to develop a representative model which simulates the performance of a biofilter used to treat drinking water. A steady-sate model is applied. The Monod-type substrate utilization is use...The aim of this research is to develop a representative model which simulates the performance of a biofilter used to treat drinking water. A steady-sate model is applied. The Monod-type substrate utilization is used, and the external and the internal mass transfer are neglected in this model. The model describes the process of substrate biodegradation, bacterial attachment onto filter media, and detachment of suspended bacteria. It simulates the natural organic matter （NOM） and biomass profiles in a biofilter as a function of filter depth and filtration velocity. The key biokinefie parameters k and Ks are estimated through a special experiment. The results of the model testing show that the model prediction agrees well with the experimental data.展开更多
Purpose： To investigate the influence of the same mechanical loading on osteogenesis and osteoclastogenesis in vitro. Methods： Primary osteoblasts, bone marrow-derived mesenchymal stem cells （BMSCs, cultured in ost...Purpose： To investigate the influence of the same mechanical loading on osteogenesis and osteoclastogenesis in vitro. Methods： Primary osteoblasts, bone marrow-derived mesenchymal stem cells （BMSCs, cultured in osteoinductive medium） and RAW264.7 cells cultured in osteoclast inductive medium were all subjected to a 1000μstrain （μs） at 1 Hz cyclic mechanical stretch for 30 min （twice a day）. Results： After mechanical stimulation, the alkaline phosphatase （ALP） activity, osteocalcin protein level of the osteoblasts and BMSCs were all enhanced, and the mRNA levels of ALP and collagen type I increased. Additionally, extracellular-deposited calcium of both osteoblasts and BMSCs increased. At the same time, the activity of secreted tartrate-resistant acid phosphatase, the number of tartrate-resistant acid phosphatase-positive multinucleated cells, matrix metalloproteinase-9 protein levels of RAW264.7 cells and the extracellular calcium solvency all decreased. Conclusion： The results demonstrated that 1000 μs cyclic mechanical loading enhanced osteoblasts activity, promoted osteoblastic differentiation of BMSCs and restrained osteoclastogenesis of RAW264.7 cells in vitro.展开更多
基金National Natural Science Foundation of China(No.50638020)Science-Technology Creation Plan for Graduate Students of Jiangsu Province of China(No.1061B06013)
文摘The aim of this research is to develop a representative model which simulates the performance of a biofilter used to treat drinking water. A steady-sate model is applied. The Monod-type substrate utilization is used, and the external and the internal mass transfer are neglected in this model. The model describes the process of substrate biodegradation, bacterial attachment onto filter media, and detachment of suspended bacteria. It simulates the natural organic matter （NOM） and biomass profiles in a biofilter as a function of filter depth and filtration velocity. The key biokinefie parameters k and Ks are estimated through a special experiment. The results of the model testing show that the model prediction agrees well with the experimental data.
基金This work was financially supported by the National Natural Science Foundation of China （No.11372351, No.31370942, No.81160223）, and Scientific Research Foundation of Guangxi Higher Education （No.KY2015LX241）.
文摘Purpose： To investigate the influence of the same mechanical loading on osteogenesis and osteoclastogenesis in vitro. Methods： Primary osteoblasts, bone marrow-derived mesenchymal stem cells （BMSCs, cultured in osteoinductive medium） and RAW264.7 cells cultured in osteoclast inductive medium were all subjected to a 1000μstrain （μs） at 1 Hz cyclic mechanical stretch for 30 min （twice a day）. Results： After mechanical stimulation, the alkaline phosphatase （ALP） activity, osteocalcin protein level of the osteoblasts and BMSCs were all enhanced, and the mRNA levels of ALP and collagen type I increased. Additionally, extracellular-deposited calcium of both osteoblasts and BMSCs increased. At the same time, the activity of secreted tartrate-resistant acid phosphatase, the number of tartrate-resistant acid phosphatase-positive multinucleated cells, matrix metalloproteinase-9 protein levels of RAW264.7 cells and the extracellular calcium solvency all decreased. Conclusion： The results demonstrated that 1000 μs cyclic mechanical loading enhanced osteoblasts activity, promoted osteoblastic differentiation of BMSCs and restrained osteoclastogenesis of RAW264.7 cells in vitro.
