Objective To develop a nationally acceptable blood pressure(BP)reference standards for the diagnosis and evaluation of hypertension in children and adolescents in China.Methods The current study was based on the data ...Objective To develop a nationally acceptable blood pressure(BP)reference standards for the diagnosis and evaluation of hypertension in children and adolescents in China.Methods The current study was based on the data from eleven large-scale cross-sectional BP surveys in China's Mainland since 2001,the survey sites were representative of national geographical distribution including four municipalities(Beijing,Shanghai,Tianjin,Chongqing)and seven provinces(Hunan,Liaoning,Hebei,Zhejiang,Guangxi,Xinqiang and Guangdong).The surveys which met the following selection criteria were involved to form the reference population sample and pooled database:1)Subjects were Han nationality and their ages were from 3 to 18 years old;2)BP levels were measured by auscultation using standard sphygmomanometer and recorded as Korotkoff phase 1(SBP),Korotkoff phase 4(DBP-K4)and/or Korotkoff phase 5(DBP-K5);3)All surveyors were trained before investigations and standard quality control was implemented throughout the BP measuring process;4)Basic variables,except BPs,were at least included but not limited to age,sex,nationality,height and weight.Totally 112 227 subjects(56 912 males accounting for 50.7%)were enrolled in the reference population sample in this study.SPSS 13.0 software was used to do the descriptive statistical analysis.Centile curves for SBP,DBP-K4 and DBP-K5 were drawn by sex using LMS method.Z scores of Height and BMI were calculated based on the data from the Chinese National Survey on Constitution and Health(CNSCH)in schoolchildren in 2005 to evaluate the nutrition status and development level of the reference population.Results The reference population had an optimal representation of Chinese Han children and adolescents.The resulting curves provided specific cut off points based on age and sex for the diagnosis of high normal BP,hypertension and severe hypertension,respectively.Given the best approach for blood pressure measurement in children and adolescents remained controversial,especially on the choice of K4 or K5 for diastolic blood pressure.So in present study we showed DBP reference standards with K4 and K5,respectively,that is,two sets of SBP/DBP-K4 and SBP/DBP-K5 were developed for the flexible usage in practice.The proposed reference standards of SBP/DBP-K4 were similar to the US fourth report on the diagnosis,evaluation,and treatment of high blood pressure in children and adolescents,with only exception of the age groups of preschool children and late adolescence.Cut off points for hypertension using DBP-K5 were significantly lower than the US standards.Conclusions The proposed reference standards,which were firstly developed based on the most recently pooled national data and in line with the growth and development characteristics of Chinese children and adolescents,should help for the early screening,diagnosis and evaluation of hypertension in children and adolescents,and were also recommended to be used in national comparisons of prevalence of hypertension.展开更多
用超声波和微波辐射法在氧化体系下,对北京、王庄、兖州、临汾煤进行了氧化脱硫研究.实验结果表明,超声波和微波结合可达到较好的氧化脱硫效果,超声波作用时间和功率、微波作用时间和功率、煤样粒度、氧化剂类型以及氧化剂用量对煤中有...用超声波和微波辐射法在氧化体系下,对北京、王庄、兖州、临汾煤进行了氧化脱硫研究.实验结果表明,超声波和微波结合可达到较好的氧化脱硫效果,超声波作用时间和功率、微波作用时间和功率、煤样粒度、氧化剂类型以及氧化剂用量对煤中有机硫的脱除率有较大影响.在优化的工艺条件下:超声波功率为540 W,作用时间为70 m in,微波功率为280 W,照射时间为30 m in,煤与HAc+H2O2(体积比1∶1)氧化剂配比为3/60(g/mL),煤粒度d≤0.10 mm;王庄煤有机硫的脱除率可达到65.0%.研究表明,超声波和微波联合氧化法是脱除原煤中有机硫的一种有效方法,对不同煤样的脱硫效果不同,与煤中有机硫的存在形态有关.展开更多
文摘Objective To develop a nationally acceptable blood pressure(BP)reference standards for the diagnosis and evaluation of hypertension in children and adolescents in China.Methods The current study was based on the data from eleven large-scale cross-sectional BP surveys in China's Mainland since 2001,the survey sites were representative of national geographical distribution including four municipalities(Beijing,Shanghai,Tianjin,Chongqing)and seven provinces(Hunan,Liaoning,Hebei,Zhejiang,Guangxi,Xinqiang and Guangdong).The surveys which met the following selection criteria were involved to form the reference population sample and pooled database:1)Subjects were Han nationality and their ages were from 3 to 18 years old;2)BP levels were measured by auscultation using standard sphygmomanometer and recorded as Korotkoff phase 1(SBP),Korotkoff phase 4(DBP-K4)and/or Korotkoff phase 5(DBP-K5);3)All surveyors were trained before investigations and standard quality control was implemented throughout the BP measuring process;4)Basic variables,except BPs,were at least included but not limited to age,sex,nationality,height and weight.Totally 112 227 subjects(56 912 males accounting for 50.7%)were enrolled in the reference population sample in this study.SPSS 13.0 software was used to do the descriptive statistical analysis.Centile curves for SBP,DBP-K4 and DBP-K5 were drawn by sex using LMS method.Z scores of Height and BMI were calculated based on the data from the Chinese National Survey on Constitution and Health(CNSCH)in schoolchildren in 2005 to evaluate the nutrition status and development level of the reference population.Results The reference population had an optimal representation of Chinese Han children and adolescents.The resulting curves provided specific cut off points based on age and sex for the diagnosis of high normal BP,hypertension and severe hypertension,respectively.Given the best approach for blood pressure measurement in children and adolescents remained controversial,especially on the choice of K4 or K5 for diastolic blood pressure.So in present study we showed DBP reference standards with K4 and K5,respectively,that is,two sets of SBP/DBP-K4 and SBP/DBP-K5 were developed for the flexible usage in practice.The proposed reference standards of SBP/DBP-K4 were similar to the US fourth report on the diagnosis,evaluation,and treatment of high blood pressure in children and adolescents,with only exception of the age groups of preschool children and late adolescence.Cut off points for hypertension using DBP-K5 were significantly lower than the US standards.Conclusions The proposed reference standards,which were firstly developed based on the most recently pooled national data and in line with the growth and development characteristics of Chinese children and adolescents,should help for the early screening,diagnosis and evaluation of hypertension in children and adolescents,and were also recommended to be used in national comparisons of prevalence of hypertension.
文摘用超声波和微波辐射法在氧化体系下,对北京、王庄、兖州、临汾煤进行了氧化脱硫研究.实验结果表明,超声波和微波结合可达到较好的氧化脱硫效果,超声波作用时间和功率、微波作用时间和功率、煤样粒度、氧化剂类型以及氧化剂用量对煤中有机硫的脱除率有较大影响.在优化的工艺条件下:超声波功率为540 W,作用时间为70 m in,微波功率为280 W,照射时间为30 m in,煤与HAc+H2O2(体积比1∶1)氧化剂配比为3/60(g/mL),煤粒度d≤0.10 mm;王庄煤有机硫的脱除率可达到65.0%.研究表明,超声波和微波联合氧化法是脱除原煤中有机硫的一种有效方法,对不同煤样的脱硫效果不同,与煤中有机硫的存在形态有关.
