目的系统评价儿童维生素D水平与龋齿发生风险的关系。方法计算机检索中国期刊全文数据库(CNKI)、维普数据库(VIP)、万方数据库、PubMed、Web of Science、Cochrane Library、Embase数据库,收集有关儿童维生素D水平与龋齿发生风险关系的...目的系统评价儿童维生素D水平与龋齿发生风险的关系。方法计算机检索中国期刊全文数据库(CNKI)、维普数据库(VIP)、万方数据库、PubMed、Web of Science、Cochrane Library、Embase数据库,收集有关儿童维生素D水平与龋齿发生风险关系的流行病学观察性研究,检索时限从建库到2019年3月。由两位评价员独立筛选文献、提取资料并评价纳入研究的偏倚风险后,使用Stata 15.1软件对纳入研究进行Meta分析。结果最终纳入10篇文献共14项观察性研究,其方法学质量均较高,其中6项横断面研究为A级,3项队列研究为A级,4项病例对照研究为B级,1项孟德尔随机化研究为A级。共纳入12596例研究对象,患龋者5338例,患龋率为42.38%。其中维生素D缺乏者1075例,患龋者512例,患龋率为47.63%;维生素D不足者3676例,患龋者1580例,患龋率为42.98%;维生素D水平正常者7845例,患龋者3246例,患龋率为41.38%。Meta分析结果显示,维生素D缺乏或不足者龋齿的发生风险较维生素D水平正常者升高11%(RR=1.11,95%CI 1.01~1.21,P=0.03)。根据研究类型进行亚组分析,4项病例对照研究结果显示,维生素D缺乏或不足者龋齿的发生风险较维生素D水平正常者升高61%(RR=1.61,95%CI 1.09~2.39,P=0.01);6项横断面研究及3项队列研究结果显示,维生素D缺乏或不足者龋齿的发生风险与维生素D水平正常者差异无统计学意义。根据年龄进行亚组分析,乳牙期组维生素D缺乏或不足者龋齿的发生风险较维生素D水平正常者升高74%(RR=1.74,95%CI1.37~2.21,P<0.01);恒牙期及替牙期组维生素D缺乏或不足者龋齿的发生风险与维生素D水平正常者差异无统计学意义。结论儿童维生素D水平与龋齿发生风险相关,维生素D缺乏或不足可增加龋齿的发生风险。展开更多
Soil erosion and loss of soil nutrients have been a crucial environment threat in Southwest China. The land use and its impact on soil qualities continue to be highlighted. The present study was conducted to compare s...Soil erosion and loss of soil nutrients have been a crucial environment threat in Southwest China. The land use and its impact on soil qualities continue to be highlighted. The present study was conducted to compare soil erosion under four land use types(i.e.,forestland, abandoned farmland, tillage, and grassland) and their effects on soil organic carbon(SOC), total nitrogen(TN) and total phosphorus(TP) in the Shuanglong catchment of the Dianchi Lake watershed, China. There were large variations in the erosion rate and the nutrient distributions across the four land use types. The erosion rates estimated by137 Cs averaged 2 133 t km-2year-1under tillage and abandoned farmland over the erosion rate of non-cultivated sites, and the grasslands showed a net deposition. For all sites, the nutrient contents basically decreased with the soil depth. Compared with tillage and abandoned farmland, grassland had the highest SOC and TN contents within 0–40 cm soil layer, followed by forestland. The significant correlations between137 Cs, SOC and TN were observed. The nutrient loss caused by erosion in tillage was the highest. These results suggested that grassland and forestland would be beneficial for SOC and TN sequestration over a long-term period because of their ability to reduce the loss of nutrients by soil erosion. Our study demonstrated that reduction of nutrient loss in the red soil area could be made through well-managed vegetation restoration measures.展开更多
基金supported by the National Natural Science Foundation of China(Nos.41273102,41030751 and 41273103)
文摘Soil erosion and loss of soil nutrients have been a crucial environment threat in Southwest China. The land use and its impact on soil qualities continue to be highlighted. The present study was conducted to compare soil erosion under four land use types(i.e.,forestland, abandoned farmland, tillage, and grassland) and their effects on soil organic carbon(SOC), total nitrogen(TN) and total phosphorus(TP) in the Shuanglong catchment of the Dianchi Lake watershed, China. There were large variations in the erosion rate and the nutrient distributions across the four land use types. The erosion rates estimated by137 Cs averaged 2 133 t km-2year-1under tillage and abandoned farmland over the erosion rate of non-cultivated sites, and the grasslands showed a net deposition. For all sites, the nutrient contents basically decreased with the soil depth. Compared with tillage and abandoned farmland, grassland had the highest SOC and TN contents within 0–40 cm soil layer, followed by forestland. The significant correlations between137 Cs, SOC and TN were observed. The nutrient loss caused by erosion in tillage was the highest. These results suggested that grassland and forestland would be beneficial for SOC and TN sequestration over a long-term period because of their ability to reduce the loss of nutrients by soil erosion. Our study demonstrated that reduction of nutrient loss in the red soil area could be made through well-managed vegetation restoration measures.
