We assessed the secular trends in the serum lipid levels in Shanghai residents from 1973 to 1999.Data from four independent,cross-sectional,population-based surveys were used to analyze the trends in serum lipid level...We assessed the secular trends in the serum lipid levels in Shanghai residents from 1973 to 1999.Data from four independent,cross-sectional,population-based surveys were used to analyze the trends in serum lipid levels from 1973 to 1999.A standard protocol was applied across each survey in at least three independent surveys which were separated a 10-year study period.A total of 10733(1385,3302,2399,and 3647 subjects who had complete data on serum lipids in 1973-1974,1982,1983 and 1997-1999,respectively)Shanghai residents aged from newborn to 80 years old were enlisted at random.Serum lipid levels were measured in a single laboratory throughout the entire study period.A nonsignificant increase was noted from 1973-1974 to 1982-1983 in the serum lipid profiles;however,a significant increase was observed from 1982-1983 to 1997-1999 in most of the age groups of both sexes.Mean serum total cholesterol(TC)levels increased significantly(P<0.05)over the entire study period(overall period covered:1973-1999)in most age groups of both sexes.In males,the changes were from 7.3%to 23.2%and in females,from 9.0%to 21.6%,except in umbilical blood samples and in females over 60 years where insignificant results were observed.Similar trends were observed in the mean serum triglyceride(TG)and the mean serum low-density lipoprotein cholesterol(LDL-c)levels,both in females and males.The majority show an upward trend.As for TGs,the changes were from 27.5%to 82.7%in males and from 13.2%to 54.6%in females.As for LDL-c the changes were from 34.9%to 71.0%in males and from 31.9%to 63.6%in females.Mean serum high-density lipoprotein cholesterol(HDL-c)levels were decreased significantly from 1982-1983 to 1997-1999,with the changes from 213.2%to 238.6%in males and from 29.8%to 221.7%in females.The ratio of total cholesterol to high-density lipoprotein cholesterol(TC/HDL-c)increased dramatically during this period because of a concurrent decline in the levels of HDL-c and the increase in the levels of TC.The prevalence of hypercholesterolemia(To achieve the normal range of serum TC and TG in healthy people of Shanghai,we determined the cut-off point in the cumulative frequency curve as the 95%percentile of the data collected by the survey in 1973-1974.The results show that the 95%cut-off point for TC was 220 mg/dL,while for TG,it was 160 mg/dL.)increased significantly(P<0.05).In males aged 20 to 40 years old,the prevalence of hypercholesterolemia was from 1.6%to 7.79%,and in ages>40 it was from 5.5%to 11.57%.In females,it was 0 to 4.68%and 6.5%to 16.2%,respectively.In general,the trends in the levels of TC,TG and LDL-c were increasing and trends in the levels of HDL-c were decreasing in most age groups,especially,in the younger age group of Shanghai residents from 1980s to 1990s.These worrying findings are significant for its public health implications.Health education and health promotion are necessary to prevent the disease prevalence from rising in the Chinese population.展开更多
This paper reports the effects of shear force on anoxic granular sludge in sequencing batch reactors （SBR）. The study was carried out in two SBRs （SBR1 and SBR2） in which sodium acetate （200mg COD·L^-1） was...This paper reports the effects of shear force on anoxic granular sludge in sequencing batch reactors （SBR）. The study was carried out in two SBRs （SBR1 and SBR2） in which sodium acetate （200mg COD·L^-1） was used as the sole substrate and sodium nitrate （40 mgNO3-N·L^-1） was employed as the electron acceptor. The preliminary objective of this study was to cultivate anoxic granules in the SBR in order to investigate the effects of shear force on the formation of anoxic granular sludge and to compare the properties of anoxic sludge in the SBR. This study reports new results for the values of average velocity gradient, a measure of the applied shear force, which was varied in the two SBRs （3.79 s^-1 and 9.76 s^-1 for SBR1 and SBR2 respectively）. The important findings of this research highlight the dual effects of shear force on anoxic granules. A low shear force can produce large anoxic granules with high activity and poor settling ability, whereas higher shear forces produce smaller granules with better settling ability and lower activity. The results of this study show that the anoxic granulation is closely related to the strength of the shear force. For high shear force, this research demonstrated that： 1） granules with smaller diameters, high density and good settling ability were formed in the reactor, and 2） granular sludge formed faster than it did in the low shear force reactor （41days versus 76 days）. Once a steady-state has been achieved, the nitrate and COD removal rates were found to be 98% and 80%, respectively. For low shear force, such as was applied in SBR1, this research demonstrated that： 1） the activity of anoxic granular sludge in low shear force was higher than that in high shear force, 2） higher amount of soluble microbial products （SMPs） were produced, and 3） large pores were observed inside the larger granules,which are beneficial for nitrogen gas diffusion. Electron microscopic examination of the anoxic granules in both reactors showed that the morphology of the granules was ellipsoidal with a clear outline. Coccus and rod-shaped bacteria were wrapped by filamentous bacteria on the surface of granule.展开更多
文摘We assessed the secular trends in the serum lipid levels in Shanghai residents from 1973 to 1999.Data from four independent,cross-sectional,population-based surveys were used to analyze the trends in serum lipid levels from 1973 to 1999.A standard protocol was applied across each survey in at least three independent surveys which were separated a 10-year study period.A total of 10733(1385,3302,2399,and 3647 subjects who had complete data on serum lipids in 1973-1974,1982,1983 and 1997-1999,respectively)Shanghai residents aged from newborn to 80 years old were enlisted at random.Serum lipid levels were measured in a single laboratory throughout the entire study period.A nonsignificant increase was noted from 1973-1974 to 1982-1983 in the serum lipid profiles;however,a significant increase was observed from 1982-1983 to 1997-1999 in most of the age groups of both sexes.Mean serum total cholesterol(TC)levels increased significantly(P<0.05)over the entire study period(overall period covered:1973-1999)in most age groups of both sexes.In males,the changes were from 7.3%to 23.2%and in females,from 9.0%to 21.6%,except in umbilical blood samples and in females over 60 years where insignificant results were observed.Similar trends were observed in the mean serum triglyceride(TG)and the mean serum low-density lipoprotein cholesterol(LDL-c)levels,both in females and males.The majority show an upward trend.As for TGs,the changes were from 27.5%to 82.7%in males and from 13.2%to 54.6%in females.As for LDL-c the changes were from 34.9%to 71.0%in males and from 31.9%to 63.6%in females.Mean serum high-density lipoprotein cholesterol(HDL-c)levels were decreased significantly from 1982-1983 to 1997-1999,with the changes from 213.2%to 238.6%in males and from 29.8%to 221.7%in females.The ratio of total cholesterol to high-density lipoprotein cholesterol(TC/HDL-c)increased dramatically during this period because of a concurrent decline in the levels of HDL-c and the increase in the levels of TC.The prevalence of hypercholesterolemia(To achieve the normal range of serum TC and TG in healthy people of Shanghai,we determined the cut-off point in the cumulative frequency curve as the 95%percentile of the data collected by the survey in 1973-1974.The results show that the 95%cut-off point for TC was 220 mg/dL,while for TG,it was 160 mg/dL.)increased significantly(P<0.05).In males aged 20 to 40 years old,the prevalence of hypercholesterolemia was from 1.6%to 7.79%,and in ages>40 it was from 5.5%to 11.57%.In females,it was 0 to 4.68%and 6.5%to 16.2%,respectively.In general,the trends in the levels of TC,TG and LDL-c were increasing and trends in the levels of HDL-c were decreasing in most age groups,especially,in the younger age group of Shanghai residents from 1980s to 1990s.These worrying findings are significant for its public health implications.Health education and health promotion are necessary to prevent the disease prevalence from rising in the Chinese population.
基金Acknowledgements This work was supported by the National Natural Science Foundation of China （Grant No. 50838005） and National Water Pollution Control and Management Technology Major Projects of China （No. 2009ZX07317-009）. The authors are grateful for much assistance with microsensor measurements from Xi＇an University Architecture and Technol- ogy.
文摘This paper reports the effects of shear force on anoxic granular sludge in sequencing batch reactors （SBR）. The study was carried out in two SBRs （SBR1 and SBR2） in which sodium acetate （200mg COD·L^-1） was used as the sole substrate and sodium nitrate （40 mgNO3-N·L^-1） was employed as the electron acceptor. The preliminary objective of this study was to cultivate anoxic granules in the SBR in order to investigate the effects of shear force on the formation of anoxic granular sludge and to compare the properties of anoxic sludge in the SBR. This study reports new results for the values of average velocity gradient, a measure of the applied shear force, which was varied in the two SBRs （3.79 s^-1 and 9.76 s^-1 for SBR1 and SBR2 respectively）. The important findings of this research highlight the dual effects of shear force on anoxic granules. A low shear force can produce large anoxic granules with high activity and poor settling ability, whereas higher shear forces produce smaller granules with better settling ability and lower activity. The results of this study show that the anoxic granulation is closely related to the strength of the shear force. For high shear force, this research demonstrated that： 1） granules with smaller diameters, high density and good settling ability were formed in the reactor, and 2） granular sludge formed faster than it did in the low shear force reactor （41days versus 76 days）. Once a steady-state has been achieved, the nitrate and COD removal rates were found to be 98% and 80%, respectively. For low shear force, such as was applied in SBR1, this research demonstrated that： 1） the activity of anoxic granular sludge in low shear force was higher than that in high shear force, 2） higher amount of soluble microbial products （SMPs） were produced, and 3） large pores were observed inside the larger granules,which are beneficial for nitrogen gas diffusion. Electron microscopic examination of the anoxic granules in both reactors showed that the morphology of the granules was ellipsoidal with a clear outline. Coccus and rod-shaped bacteria were wrapped by filamentous bacteria on the surface of granule.
