The concept of temperature staged and biological phased （TSBP） was proposed to enhance the performance of waste-activated sludge anaerobic digestion. Semi-continuous experiments were used to investigate the effect o...The concept of temperature staged and biological phased （TSBP） was proposed to enhance the performance of waste-activated sludge anaerobic digestion. Semi-continuous experiments were used to investigate the effect of temperature （35 to 70℃） as well as the hydraulic retention time （HRT） （2, 4 and 6 days） on the acidogenic phase. The results showed that the solubilization degree of waste- activated sludge increased from 14.7% to 30.1% with temperature increasing from 35 to 70℃, while the acidification degree was highest at 45℃ （17.6%）, and this was quite different from the temperature impact on hydrolysis. Compared with HRT of 2 and 6 days, 4 days was chosen as the appropriate HRT because of its relatively high solubilization degree （24.6%） and acidification degree （20.1%） at 45℃. The TSBP system combined the acidogenic reactor （45℃, 4 days） with the methanogenic reactor （35℃, 16 days） and the results showed 84.8% and 11.4% higher methane yield and volatile solid reduction, respectively, compared with that of the single-stage anaerobic digestion system with HRT of 20 days at 35℃. Moreover, different microbial morphologies were observed in the acidogenic- and methanogenic-phase reactors, which resulted from the temperature control and HRT adjustment. All the above results indicated that 45℃ was the optimum temperature to inhibit the activity of methanogenic bacteria in the acidogenic phase, and temperature staging and phase separation was thus accomplished. The advantages of the TSBP process were also confirmed by a full-scale waste-activated sludge anaerobic digestion project which was an energy self-sufficient system.展开更多
To the Editor:Transcatheter aortic valve replacement(TAVR)has become an established treatment for patients with severe aortic stenosis(AS)at all levels of surgical risk.^([1,2])With the exploration of TAVR and technol...To the Editor:Transcatheter aortic valve replacement(TAVR)has become an established treatment for patients with severe aortic stenosis(AS)at all levels of surgical risk.^([1,2])With the exploration of TAVR and technological developments,TAVR is an alternative for patients with intermediate or low surgical risk.^([3])There are some studies regarding gender differences in TAVR,but there are few studies on it in Asia.^([4])However,the studies of outcomes based on gender differences in TVAR are still lacking,especially in China and other Asian countries.展开更多
Bed expansion serves an important function in the design and operation of an upflow anaerobic reactor. An analysis of the flow pattern of expanded granular sludge bed （EGSB） reactors shows that most EGSB reactors do...Bed expansion serves an important function in the design and operation of an upflow anaerobic reactor. An analysis of the flow pattern of expanded granular sludge bed （EGSB） reactors shows that most EGSB reactors do not behave as expanded bed reactors, as is widely perceived. Rather, these reactors behave as fluidized bed reactors based on the classic chemical reactor theory. In this paper, four bed expansion modes, divided as static bed, expanded bed, suspended bed, and fluidized bed, for bioreactors are proposed. A high-rate anaerobic suspended granular sludge bed （SGSB） reactor was then developed. The SGSB reactor is an upflow anaerobic reactor, and its expansion degree can be easily controlled within a range to maintain the suspended status of the sludge bed by controlling upfiow velocity. The results of the full-scale reactor confirmed that the use of SGSB reactors is advantageous. The full-scale SGSB reactor runs stably and achieves high COD removal efficiency （about 90%） at high loading rates （average 40 kg-COD·m^-3·d^-1, maximum to 52 kg·COD·m^-3 ·d^-1） based on the SGSB theory, and its expansion degree is between 22% and 37%.展开更多
To the Editor:Approximately 2%of people>65 years old have aortic stenosis(AS).[1]Without intervention,AS is a rapidly progressive valvular heart disease with a 2-year mortality of 50%.[1]Since the first transcathet...To the Editor:Approximately 2%of people>65 years old have aortic stenosis(AS).[1]Without intervention,AS is a rapidly progressive valvular heart disease with a 2-year mortality of 50%.[1]Since the first transcatheter aortic valve replacement(TAVR)was performed by Cribier et al[2]in 2002,TAVR has been suggested to be non-inferior in AS patients of various risk stratifications.Post-TAVR complications are essential in predicting patient survival and improving quality of life,especially with the procedure being performed in an increasing population of low-risk patients.[3]Among them,myocardial infarction(MI)is a rare but life-threatening complication usually caused by the obstruction of coronary ostia.[1]In comparison,peri-procedural myocardial injury,primarily characterized by the elevation of cardiac markers,is a relatively common complication of TAVR.Although recent studies have demonstrated promising results of cardiac markers in predicting cardiovascular adverse events,the impact of peri-procedural myocardial injury on short-term and long-term mortality has yet to be established.展开更多
基金supported by the National Hi-Tech Research and Development Program (863) of China (No.2009AA064702,2011AA060901)
文摘The concept of temperature staged and biological phased （TSBP） was proposed to enhance the performance of waste-activated sludge anaerobic digestion. Semi-continuous experiments were used to investigate the effect of temperature （35 to 70℃） as well as the hydraulic retention time （HRT） （2, 4 and 6 days） on the acidogenic phase. The results showed that the solubilization degree of waste- activated sludge increased from 14.7% to 30.1% with temperature increasing from 35 to 70℃, while the acidification degree was highest at 45℃ （17.6%）, and this was quite different from the temperature impact on hydrolysis. Compared with HRT of 2 and 6 days, 4 days was chosen as the appropriate HRT because of its relatively high solubilization degree （24.6%） and acidification degree （20.1%） at 45℃. The TSBP system combined the acidogenic reactor （45℃, 4 days） with the methanogenic reactor （35℃, 16 days） and the results showed 84.8% and 11.4% higher methane yield and volatile solid reduction, respectively, compared with that of the single-stage anaerobic digestion system with HRT of 20 days at 35℃. Moreover, different microbial morphologies were observed in the acidogenic- and methanogenic-phase reactors, which resulted from the temperature control and HRT adjustment. All the above results indicated that 45℃ was the optimum temperature to inhibit the activity of methanogenic bacteria in the acidogenic phase, and temperature staging and phase separation was thus accomplished. The advantages of the TSBP process were also confirmed by a full-scale waste-activated sludge anaerobic digestion project which was an energy self-sufficient system.
基金supported by grants from the West China Hospital“1·3·5”Discipline of Excellence Project-“Mechanisms of aortic stenosis and the clinical applications”,National Natural Science Foundation of China(No.82001899)the National Natural Science Foundation of China(No.81901825).
文摘To the Editor:Transcatheter aortic valve replacement(TAVR)has become an established treatment for patients with severe aortic stenosis(AS)at all levels of surgical risk.^([1,2])With the exploration of TAVR and technological developments,TAVR is an alternative for patients with intermediate or low surgical risk.^([3])There are some studies regarding gender differences in TAVR,but there are few studies on it in Asia.^([4])However,the studies of outcomes based on gender differences in TVAR are still lacking,especially in China and other Asian countries.
基金Acknowledgements This study was supported by the National Natural Science Foundation of China （Grant Nos. 50978146 and 51278271） and by the Environmental Scientific Research in the Public Interest （No. 201009017） from the Ministry of Environmental Protection of China.
文摘Bed expansion serves an important function in the design and operation of an upflow anaerobic reactor. An analysis of the flow pattern of expanded granular sludge bed （EGSB） reactors shows that most EGSB reactors do not behave as expanded bed reactors, as is widely perceived. Rather, these reactors behave as fluidized bed reactors based on the classic chemical reactor theory. In this paper, four bed expansion modes, divided as static bed, expanded bed, suspended bed, and fluidized bed, for bioreactors are proposed. A high-rate anaerobic suspended granular sludge bed （SGSB） reactor was then developed. The SGSB reactor is an upflow anaerobic reactor, and its expansion degree can be easily controlled within a range to maintain the suspended status of the sludge bed by controlling upfiow velocity. The results of the full-scale reactor confirmed that the use of SGSB reactors is advantageous. The full-scale SGSB reactor runs stably and achieves high COD removal efficiency （about 90%） at high loading rates （average 40 kg-COD·m^-3·d^-1, maximum to 52 kg·COD·m^-3 ·d^-1） based on the SGSB theory, and its expansion degree is between 22% and 37%.
基金supported by the National Natural Science Foundation of China(No.82001899)West China Hospital"1·3·5"Discipline of Excellence Project—"Mechanisms of aortic stenosis and the clinical applications".
文摘To the Editor:Approximately 2%of people>65 years old have aortic stenosis(AS).[1]Without intervention,AS is a rapidly progressive valvular heart disease with a 2-year mortality of 50%.[1]Since the first transcatheter aortic valve replacement(TAVR)was performed by Cribier et al[2]in 2002,TAVR has been suggested to be non-inferior in AS patients of various risk stratifications.Post-TAVR complications are essential in predicting patient survival and improving quality of life,especially with the procedure being performed in an increasing population of low-risk patients.[3]Among them,myocardial infarction(MI)is a rare but life-threatening complication usually caused by the obstruction of coronary ostia.[1]In comparison,peri-procedural myocardial injury,primarily characterized by the elevation of cardiac markers,is a relatively common complication of TAVR.Although recent studies have demonstrated promising results of cardiac markers in predicting cardiovascular adverse events,the impact of peri-procedural myocardial injury on short-term and long-term mortality has yet to be established.
