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展开更多
大气氮素湿沉降与氮的排放紧密相关,通过对已知的氮素排放数据与收集的氮素湿沉降实测数据对应分析发现,不同地区氮素的排放与湿沉降之间存在稳定的比值关系。根据这些比值关系,估算了1980—2007年中国大陆氮素湿沉降量,并运用GIS技术...大气氮素湿沉降与氮的排放紧密相关,通过对已知的氮素排放数据与收集的氮素湿沉降实测数据对应分析发现,不同地区氮素的排放与湿沉降之间存在稳定的比值关系。根据这些比值关系,估算了1980—2007年中国大陆氮素湿沉降量,并运用GIS技术进行了大气氮素湿沉降强度和时空分布。结果表明,我国大陆区域氮素湿沉降呈明显的增长趋势,沉降总量由1980年的4.96Tg增长到2007年的11.80 Tg,单位面积通量分别为516 kg N.km-2.a-1和1 128 kg N.km-2.a-1。氮素湿沉降的空间分布不均,东部、东南沿海地区和中部地区沉降量较高,广大西部地区较低。化学氮肥的施用、燃料的使用和禽畜养殖规模扩大是导致氮湿沉降量增加的主要原因。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
文摘大气氮素湿沉降与氮的排放紧密相关,通过对已知的氮素排放数据与收集的氮素湿沉降实测数据对应分析发现,不同地区氮素的排放与湿沉降之间存在稳定的比值关系。根据这些比值关系,估算了1980—2007年中国大陆氮素湿沉降量,并运用GIS技术进行了大气氮素湿沉降强度和时空分布。结果表明,我国大陆区域氮素湿沉降呈明显的增长趋势,沉降总量由1980年的4.96Tg增长到2007年的11.80 Tg,单位面积通量分别为516 kg N.km-2.a-1和1 128 kg N.km-2.a-1。氮素湿沉降的空间分布不均,东部、东南沿海地区和中部地区沉降量较高,广大西部地区较低。化学氮肥的施用、燃料的使用和禽畜养殖规模扩大是导致氮湿沉降量增加的主要原因。
