The effects of large piece xenogeneic bone which was separated from healthy pigs as a scaffold on repair of mandibular defect was investigated and the applicability of antigen-extracted xenogeneic cancellous bone (AXC...The effects of large piece xenogeneic bone which was separated from healthy pigs as a scaffold on repair of mandibular defect was investigated and the applicability of antigen-extracted xenogeneic cancellous bone (AXCB) soaked with rhBMP-2 in bone defect repair was assessed. Mandibular defects were created in 48 New Zealand Rabbits, and then randomly divided into 4 groups, which was grafted in the mandibular defects with AXCB, AXCB soaked with rhBMP-2, autograft bone, or blank. Equal number of animals from each group was classified into three time points (4, 8, and 12 weeks) after operation for gross pathological observation, hematoxylin and eosin (H & E) staining, radiographic examination, and bone density measurement. H & E staining revealed that the area percentage of bone regeneration in the group of AXCB/rhBMP-2 graft was 27.72 ± 4.68, 53.90 ± 21.92, and 77.35 ± 9.83 when at 4, 8, and 12 weeks, which was better than that of auto bone graft, prompting that the group of AXCB/rhBMP-2 graft had commendable osteogenic effect. And comparing with the AXCB without rhBMP-2, of which the area percentage of bone regeneration was only 14.03 ± 5.02, 28.49 ± 11.35, and 53.90 ± 21.92, the osteogenic effect of AXCB/rhBMP-2 graft was demonstrated to be much better. In the group of AXCB/rhBMP-2 graft, the area percentage of bone regeneration increased, and the implanted materials were gradually degraded and replaced by autogenous bone regeneration over time. We concluded that antigen-extracted xenogeneic cancellous bone (AXCB) graft soaked with rhBMP-2 had shown excellent osteogenic effect in repair of bone defects, with good biocompability.展开更多
Vessel emissions have contributed a great deal to air quality deterioration in China.Hence,the Chinese government has promulgated a series of stringent emission regulations.It is in this context that vessel emission c...Vessel emissions have contributed a great deal to air quality deterioration in China.Hence,the Chinese government has promulgated a series of stringent emission regulations.It is in this context that vessel emission control technology research is in full swing.In particular,during the 13th Five-Year Plan,the air pollution control technology of vessels has greatly improved.Vessel emission control has followed two main governance routes:source emission reduction and aftertreatment technology.Source control focuses on alternative fuels,with two main directions,the development of new fuels and the modification of existing fuels.Moreover,after-treatment technologies have also been developed,including wet desulfurization technology using seawater or alkaline liquids as wet washing liquids and selective catalytic reduction(SCR)for the control of NOx emission.Due to China’s increasingly stringent emissions standards and regulations,work on the development of clean alternative fuels and further upgrading the collaborative application of after-treatment technologies to meet the near-zero-emissions requirements of vessels is still necessary.展开更多
The implementation of ultra-low emission(ULE)limits(SO_(2):35 mg/m3,NOx:50 mg/m3,PM:10 mg/m3)promoted the development of flue gas treatment technologies in China.Pollutant control technology development for Chinese co...The implementation of ultra-low emission(ULE)limits(SO_(2):35 mg/m3,NOx:50 mg/m3,PM:10 mg/m3)promoted the development of flue gas treatment technologies in China.Pollutant control technology development for Chinese coal-fired power plants was summarized and an analysis of the applicability and cost of pollutant control technologies was conducted.Detailed data were collected from 30 ultra-low emission coal-fired units across China.Based on a cost analysis model,the average unit power generation incremental costs were 0.0144and 0.0095 CNY/(kW·hr)for SO_(2)and NOx control technologies,respectively.The unit power generation incremental cost of twin spray tower technology was 7.2%higher than that of dual-loop spray tower technology.The effect of key parameters on operating cost was analyzed.The unit power generation incremental cost increased because of increments in the electricity price for SO_(2)control technology and the price of the reductant in NOx control technology.With high sulfur content or NOx concentration,the unit power generation incremental cost caused by pollutant control increased,whereas the unit pollutant abatement cost decreased.However,the annual operating hours or load increased,thereby leading to a decline in unit power generation incremental cost and unit pollutant abatement cost.展开更多
文摘The effects of large piece xenogeneic bone which was separated from healthy pigs as a scaffold on repair of mandibular defect was investigated and the applicability of antigen-extracted xenogeneic cancellous bone (AXCB) soaked with rhBMP-2 in bone defect repair was assessed. Mandibular defects were created in 48 New Zealand Rabbits, and then randomly divided into 4 groups, which was grafted in the mandibular defects with AXCB, AXCB soaked with rhBMP-2, autograft bone, or blank. Equal number of animals from each group was classified into three time points (4, 8, and 12 weeks) after operation for gross pathological observation, hematoxylin and eosin (H & E) staining, radiographic examination, and bone density measurement. H & E staining revealed that the area percentage of bone regeneration in the group of AXCB/rhBMP-2 graft was 27.72 ± 4.68, 53.90 ± 21.92, and 77.35 ± 9.83 when at 4, 8, and 12 weeks, which was better than that of auto bone graft, prompting that the group of AXCB/rhBMP-2 graft had commendable osteogenic effect. And comparing with the AXCB without rhBMP-2, of which the area percentage of bone regeneration was only 14.03 ± 5.02, 28.49 ± 11.35, and 53.90 ± 21.92, the osteogenic effect of AXCB/rhBMP-2 graft was demonstrated to be much better. In the group of AXCB/rhBMP-2 graft, the area percentage of bone regeneration increased, and the implanted materials were gradually degraded and replaced by autogenous bone regeneration over time. We concluded that antigen-extracted xenogeneic cancellous bone (AXCB) graft soaked with rhBMP-2 had shown excellent osteogenic effect in repair of bone defects, with good biocompability.
基金supported by the National Key Research and Development Program of China(No.2019YFC0214803)。
文摘Vessel emissions have contributed a great deal to air quality deterioration in China.Hence,the Chinese government has promulgated a series of stringent emission regulations.It is in this context that vessel emission control technology research is in full swing.In particular,during the 13th Five-Year Plan,the air pollution control technology of vessels has greatly improved.Vessel emission control has followed two main governance routes:source emission reduction and aftertreatment technology.Source control focuses on alternative fuels,with two main directions,the development of new fuels and the modification of existing fuels.Moreover,after-treatment technologies have also been developed,including wet desulfurization technology using seawater or alkaline liquids as wet washing liquids and selective catalytic reduction(SCR)for the control of NOx emission.Due to China’s increasingly stringent emissions standards and regulations,work on the development of clean alternative fuels and further upgrading the collaborative application of after-treatment technologies to meet the near-zero-emissions requirements of vessels is still necessary.
基金supported by the National Key Research and Development Program of China(No.2019YFC0214803)Zhejiang Provincial Natural Science Foundation of China(No.LQ21D050002).
文摘The implementation of ultra-low emission(ULE)limits(SO_(2):35 mg/m3,NOx:50 mg/m3,PM:10 mg/m3)promoted the development of flue gas treatment technologies in China.Pollutant control technology development for Chinese coal-fired power plants was summarized and an analysis of the applicability and cost of pollutant control technologies was conducted.Detailed data were collected from 30 ultra-low emission coal-fired units across China.Based on a cost analysis model,the average unit power generation incremental costs were 0.0144and 0.0095 CNY/(kW·hr)for SO_(2)and NOx control technologies,respectively.The unit power generation incremental cost of twin spray tower technology was 7.2%higher than that of dual-loop spray tower technology.The effect of key parameters on operating cost was analyzed.The unit power generation incremental cost increased because of increments in the electricity price for SO_(2)control technology and the price of the reductant in NOx control technology.With high sulfur content or NOx concentration,the unit power generation incremental cost caused by pollutant control increased,whereas the unit pollutant abatement cost decreased.However,the annual operating hours or load increased,thereby leading to a decline in unit power generation incremental cost and unit pollutant abatement cost.
