Preferential flow characteristics of reclaimed mine soils in a surface coal mine dump.

There are a large number of macropores/tubular channels of a few centimeters and plant roots in reclaimed dump soils, which are the main reasons for the formation of soil macropores and soil preferential flow. To systematically study the morphological characteristics and variation of soil preferential flow for different reclaimed vegetations in a dump, a dye-staining experiment and physical and chemical analysis were carried out to investigate the formation mechanism and influencing factors of soil preferential flow in the vegetation restoration process. The results indicate that there were differences in the soil water breakthrough curves for different plots. The macropore effluent rate generally increased at first and then tended to stabilize. The soil steady effluent rate decreased with increasing soil depth, which reached the maximum and minimum values at the depths of 0∼5 cm (0.0193∼0.0315 mm s-1) and 50∼60 cm (0.0028∼0.0035 mm s-1), respectively. Furthermore, the radius of soil macropores under different types of reclaimed vegetation ranged from 0.03 to 4.71 mm, most of which ranged from 0.11 to 2.36 mm. The soil macroporosity of different reclaimed vegetation types ranged from 0.03 to 16.58%, which was significantly greater than 5%. The soil macroporosity determined 65% of the variation in the steady effluent rate and 42% of the variation in the saturated hydraulic conductivity. Furthermore, the dye coverage ratio decreased as the soil layer depth increased in different plots, and there were some differences in each plot. The maximum dye coverage ratio occurred in the 0∼5 cm soil layer, which reached 90.37%. The dye coverage ratio at a depth of 0∼60 cm in six plots followed the order of Robinia pseudoacacia (26.48%) > Ulmus pumila (20.12%) > mixed forest (17.32%) > farmland (15.06%) > shrub (13.97%) > weeds (10.07%). The soil preferential flow mostly occurred in the 0∼40 cm soil depth layer, which occupied more than 93% of the total soil profile (0∼60 cm). Moreover, a Pearson correlation was used to analyze the relationship between environmental factors (soil, water, and plant factors) and the dye coverage ratio. The dye coverage ratio of soil preferential flow under different reclamation vegetations was very significantly or significantly positively correlated with the gravel content, mean radius of soil macropores, soil saturated hydraulic conductivity, root weight density, and root length density, which promoted the formation and development of soil preferential flow. This study will provide a scientific basis for understanding the formation mechanism and perfecting the research system of soil preferential flow, vegetation restoration, and reconstruction in a dump; furthermore, this research offers significance guidance in the construction of green mines and the development of regional economics.

Relationship of the old people with hypertension and metabolic syndrome / 中国基层医药

Objective To analyze the morbidity of the old people with hypertension and metabolic syndrome (MS),the characteristics of MS components distribution,and correlation hypertension and MS.Methods 438 old patients over 60 with hypertension were selected randomly from cheek-up crowd in the physical examination center of Affiliated Zhongshan Hospital of Dalian University in 2013.Abdominal girth,height,body mass were measured,and then calculated BMI.The indicators such as FPG,TC,TG,HDL-C,LDL-C were detected and analyzed.Results The total morbidity of MS in the old people with hypertension was 37.7％,39.0％ from male people,36.7％ from female people,and there was no difference between genders(x2 =0.46,P ＞ 0.05).The level of BMI,abdominal girth,FPG,and TG in the old people with MS were higher than the people without MS(t =4.83,8.53,5.08,7.29,all P ＜0.05),and HDL-C was lower than the people without MS(t =-9.67,P ＜ 0.05).The level of FPG in women was higher than that in men apparently(x2 =5.82,P ＜ 0.05),and the level of HDL-C was lower than that in men apparently (x2 =8.73,P ＜ 0.01).The risk factors to MS include BMI,abdominal girth,FPG,TG (OR =2.139,1.106,2.156,2.315,all P ＜0.05),and HDL-C is protective factor to MS(OR =0.039,P ＜0.05).Conclusion Hypertension might increase MS morbidity of old patients.Hypertension related with MS closely.The risk factors include BMI,abdominal girth,FPG,TG,on the other hand HDL-C is protective factor to MS.