The activity of caesium-137 （Bq/kg） in the crustaceous lichens and other samples was determined to prove the feasibility that crustaceous lichens work as a sensitive biology monitor to record the caesium-137 （Bq/kg...The activity of caesium-137 （Bq/kg） in the crustaceous lichens and other samples was determined to prove the feasibility that crustaceous lichens work as a sensitive biology monitor to record the caesium-137 （Bq/kg） radiation levels of terrestrial environment. The measurements were performed with GEM series HPGe （ high-purity Germanium） coaxial detector system （ADCAM -100 ） made by EC ＆ GORTEC Company in USA. It was found that the activity of caesium-137 （Bq/kg） in the crustaceous lichens was one order of magnitude higher than that found in surface soil, and was over throe orders of magnitude higher than those found in the familiar biological samples. These results proved that crustaceous lichens may be one of the most sensitive biological monitors about the remote transmission and environmental radiation levels of caesium-137.展开更多
The existing traditional methods of assessing the rates of soil loss have many limitations and are difficult to apply in the karst areas of Southwest China. Karst depressions comprise geomorphologically important sour...The existing traditional methods of assessing the rates of soil loss have many limitations and are difficult to apply in the karst areas of Southwest China. Karst depressions comprise geomorphologically important sources and sinks for sediments and associated pollutants, yet the sedimentology of many depressions is not well understood. In this paper, the 137Cs technique was employed to investigate recent sedimentation rates in a Chinese polygonal karst depression. The results indicated that the sediment deposition rates ranged from 0.91 to 1.97 mm?a?1 in the period from 1963 to 2007, and the average sediment deposition rate and specific deposit yield of the catchment were estimated to be 1.47 mm?a?1 and 20 t?km?2?a?1, respectively. The results obtained were consistent with the local monitoring data of runoff plots, confirming the validity of the overall approach. It was shown that soil loss rates were very low in some karst areas of Southwest China. Above all, the approach appears to offer valuable potential to study surface erosion by estimating sediment deposition rates of karst depressions, rather than the assessment of complicated soil erosion in stony soils of carbonate rock slopes. In addition, the spacial distribution of surface soil and 137Cs inventories was affected remarkably by the inhomogeneous dissolution of limestone under the soil. It may be an important phenomenon which exists widely in the karst areas and is significantly different from other places.展开更多
In the last few decades,the use of environmental radionuclides,particularly caesium-137(^(137)Cs),represented one of the most valid methods for estimating soil erosion.However,the cost associated with the use of the e...In the last few decades,the use of environmental radionuclides,particularly caesium-137(^(137)Cs),represented one of the most valid methods for estimating soil erosion.However,the cost associated with the use of the equipment needed for radiometric analyses is still high and,for this reason,finding more easily measurable indicators can be useful.There is a strong correlation between^(137)Cs,organic carbon(OC),nitrogen(N)and water soluble phenols(WSP)exists,indicating the latter parameters as possible early indicators of soil erosion.Based on the above assumptions,the main purpose of this work is to identify specific soil chemical parameters able to indicate early triggering of soil erosion.Specifically,several soil parameters such as pH,electric conductivity(EC),WSP,OC,N and C/N have been evaluated against^(137)Cs and on a comparative basis.In addition,since the rate of soil erosion depends on the degree of coverage and canopy structure,two different tree species(Pinus nigra laricio Poir.and Fagus sylvatica L.)have been considered in this contribution in which ten different scenarios of forest management have been analysed.The results show that the reduction in tree cover of managed sites triggers erosion and nutrient loss processes.It has been observed that the loss of^(137)Cs,compared to the control areas,is closely correlated with those of WSP,OC and N.These parameters(WSP,OC and N),more easily assessable,can be a valid tool to understand easily,triggering of erosive phenomena.展开更多
Recent development in the use of the environmental radionuclide caesium-137 for documenting rates and patterns of soil redistribution on the cultivated or uncultivated land and estimating rates of sediment deposition ...Recent development in the use of the environmental radionuclide caesium-137 for documenting rates and patterns of soil redistribution on the cultivated or uncultivated land and estimating rates of sediment deposition on floodplains represents an important advance that overcomes many of the limitations of the conventional techniques commonly applied in such investigations. A study on soil redistribution (including soil erosion and deposition) was carried out in the Dian Lake catchment, Yunnan Province, using 137Cs and selected chemical properties. The average soil erosion rate was 1,280.2 t km-2 yr-1. Soil erosion rate occurring on different parts of the slope was signifi cantly different on different parts of the slope, increasing from the top, the bottom to the middle slope. The average soil erosion rate is also different with the land use type and that of the cultivated land (1,672.8 t km-2 yr-1) is higher than of the uncultivated land (1,161.2 t km-2 yr-1). The result shows that landform, slope gradient and land use type are key factors that influence the size of soil erosion. In addition, we also f ind the SOC and TN contents and amount of the soil erosion to be correlated in the soil. With the soil erosion occurring, there are land degradation and the local eco-environmental problems, such as water eutrophication in Dian Lake.展开更多
目的分析老年腔隙性脑梗死(LI)患者血清微小RNA(miR)-377、miR-137水平及临床意义。方法选择2021年2月至2022年12月哈励逊国际和平医院收治的老年LI患者248例作为LI组,另选择同期来我院体检的健康者110例作为健康组;根据美国国立卫生研...目的分析老年腔隙性脑梗死(LI)患者血清微小RNA(miR)-377、miR-137水平及临床意义。方法选择2021年2月至2022年12月哈励逊国际和平医院收治的老年LI患者248例作为LI组,另选择同期来我院体检的健康者110例作为健康组;根据美国国立卫生研究院卒中量表(NIHSS)评分将老年LI患者248例分为神经缺损组60例(≥2分)和无神经缺损组188例(<2分)。检测血清miR-377、miR-137水平;用Pearson相关性分析和Spearman相关性分析;logistic回归分析老年LI患者神经缺损影响因素;ROC曲线评估血清miR-377、miR-137水平对老年LI及神经缺损诊断的预测价值。结果LI组血清miR-377、miR-137水平低于健康组(P<0.01)。miR-377和miR-137联合评估老年LI的曲线下面积(AUC)为0.782(95%CI:0.735~0.824),高于二者单一检测(P<0.01)。神经缺损组脑动脉硬化、血红蛋白降低、肿瘤坏死因子α(TNF-α)、白细胞介素(IL)1、IL-6、IL-17、C反应蛋白(CRP)、改良的Rankin量表(mRS)评分高于无神经缺损组(P<0.05,P<0.01),血清miR-377、miR-137水平低于无神经缺损组(0.61±0.25 vs 0.89±0.28,0.61±0.24 vs 0.85±0.27,P<0.01)。血清miR-377与miR-137水平呈正相关(P<0.01);血清miR-377、miR-137水平与TNF-α、IL-6、CRP、mRS评分均呈负相关(P<0.01)。miR-377、miR-137、TNF-α、IL-6、CRP是老年LI患者神经缺损的影响因素(P<0.01)。miR-377、miR-137联合评估老年LI患者神经缺损的AUC为0.812(95%CI:0.758~0.859),高于二者单一检测(P<0.05,P<0.01)。结论血清miR-377、miR-137水平在老年LI及其神经缺损患者血清中表达较低,检测其水平具有一定临床预测价值。展开更多
文摘The activity of caesium-137 （Bq/kg） in the crustaceous lichens and other samples was determined to prove the feasibility that crustaceous lichens work as a sensitive biology monitor to record the caesium-137 （Bq/kg） radiation levels of terrestrial environment. The measurements were performed with GEM series HPGe （ high-purity Germanium） coaxial detector system （ADCAM -100 ） made by EC ＆ GORTEC Company in USA. It was found that the activity of caesium-137 （Bq/kg） in the crustaceous lichens was one order of magnitude higher than that found in surface soil, and was over throe orders of magnitude higher than those found in the familiar biological samples. These results proved that crustaceous lichens may be one of the most sensitive biological monitors about the remote transmission and environmental radiation levels of caesium-137.
基金supported by the National Basic Research Program of China (973 Program) (Grant No. 2006CB403200)the National Natural Science Foundation of China(Grant No. 41001162)+3 种基金Knowledge Inno-vation Project of the Chinese Academy of Sciences (Grant No. KZCX2-YW-306)Provincial Governor Foundation of GuiZhou (Grant No. 2010)Opening Fund of State Key Labo-ratory of Environmental Geochemistry(Grant No. SKLEG9008)National Key Technology R & D Program (Grant Nos. 2006BAC01A09 and 2008BAD98B07)
文摘The existing traditional methods of assessing the rates of soil loss have many limitations and are difficult to apply in the karst areas of Southwest China. Karst depressions comprise geomorphologically important sources and sinks for sediments and associated pollutants, yet the sedimentology of many depressions is not well understood. In this paper, the 137Cs technique was employed to investigate recent sedimentation rates in a Chinese polygonal karst depression. The results indicated that the sediment deposition rates ranged from 0.91 to 1.97 mm?a?1 in the period from 1963 to 2007, and the average sediment deposition rate and specific deposit yield of the catchment were estimated to be 1.47 mm?a?1 and 20 t?km?2?a?1, respectively. The results obtained were consistent with the local monitoring data of runoff plots, confirming the validity of the overall approach. It was shown that soil loss rates were very low in some karst areas of Southwest China. Above all, the approach appears to offer valuable potential to study surface erosion by estimating sediment deposition rates of karst depressions, rather than the assessment of complicated soil erosion in stony soils of carbonate rock slopes. In addition, the spacial distribution of surface soil and 137Cs inventories was affected remarkably by the inhomogeneous dissolution of limestone under the soil. It may be an important phenomenon which exists widely in the karst areas and is significantly different from other places.
基金The study was supported by the Coordinated Research Project(CRP)D1.50.17 within the framework of the International Atomic Energy Agency(IAEA).
文摘In the last few decades,the use of environmental radionuclides,particularly caesium-137(^(137)Cs),represented one of the most valid methods for estimating soil erosion.However,the cost associated with the use of the equipment needed for radiometric analyses is still high and,for this reason,finding more easily measurable indicators can be useful.There is a strong correlation between^(137)Cs,organic carbon(OC),nitrogen(N)and water soluble phenols(WSP)exists,indicating the latter parameters as possible early indicators of soil erosion.Based on the above assumptions,the main purpose of this work is to identify specific soil chemical parameters able to indicate early triggering of soil erosion.Specifically,several soil parameters such as pH,electric conductivity(EC),WSP,OC,N and C/N have been evaluated against^(137)Cs and on a comparative basis.In addition,since the rate of soil erosion depends on the degree of coverage and canopy structure,two different tree species(Pinus nigra laricio Poir.and Fagus sylvatica L.)have been considered in this contribution in which ten different scenarios of forest management have been analysed.The results show that the reduction in tree cover of managed sites triggers erosion and nutrient loss processes.It has been observed that the loss of^(137)Cs,compared to the control areas,is closely correlated with those of WSP,OC and N.These parameters(WSP,OC and N),more easily assessable,can be a valid tool to understand easily,triggering of erosive phenomena.
基金sponsored by the fund on soil ero-sion and silt source of Dian Lake catchment (Grant No. 40473052).
文摘Recent development in the use of the environmental radionuclide caesium-137 for documenting rates and patterns of soil redistribution on the cultivated or uncultivated land and estimating rates of sediment deposition on floodplains represents an important advance that overcomes many of the limitations of the conventional techniques commonly applied in such investigations. A study on soil redistribution (including soil erosion and deposition) was carried out in the Dian Lake catchment, Yunnan Province, using 137Cs and selected chemical properties. The average soil erosion rate was 1,280.2 t km-2 yr-1. Soil erosion rate occurring on different parts of the slope was signifi cantly different on different parts of the slope, increasing from the top, the bottom to the middle slope. The average soil erosion rate is also different with the land use type and that of the cultivated land (1,672.8 t km-2 yr-1) is higher than of the uncultivated land (1,161.2 t km-2 yr-1). The result shows that landform, slope gradient and land use type are key factors that influence the size of soil erosion. In addition, we also f ind the SOC and TN contents and amount of the soil erosion to be correlated in the soil. With the soil erosion occurring, there are land degradation and the local eco-environmental problems, such as water eutrophication in Dian Lake.
文摘目的分析老年腔隙性脑梗死(LI)患者血清微小RNA(miR)-377、miR-137水平及临床意义。方法选择2021年2月至2022年12月哈励逊国际和平医院收治的老年LI患者248例作为LI组,另选择同期来我院体检的健康者110例作为健康组;根据美国国立卫生研究院卒中量表(NIHSS)评分将老年LI患者248例分为神经缺损组60例(≥2分)和无神经缺损组188例(<2分)。检测血清miR-377、miR-137水平;用Pearson相关性分析和Spearman相关性分析;logistic回归分析老年LI患者神经缺损影响因素;ROC曲线评估血清miR-377、miR-137水平对老年LI及神经缺损诊断的预测价值。结果LI组血清miR-377、miR-137水平低于健康组(P<0.01)。miR-377和miR-137联合评估老年LI的曲线下面积(AUC)为0.782(95%CI:0.735~0.824),高于二者单一检测(P<0.01)。神经缺损组脑动脉硬化、血红蛋白降低、肿瘤坏死因子α(TNF-α)、白细胞介素(IL)1、IL-6、IL-17、C反应蛋白(CRP)、改良的Rankin量表(mRS)评分高于无神经缺损组(P<0.05,P<0.01),血清miR-377、miR-137水平低于无神经缺损组(0.61±0.25 vs 0.89±0.28,0.61±0.24 vs 0.85±0.27,P<0.01)。血清miR-377与miR-137水平呈正相关(P<0.01);血清miR-377、miR-137水平与TNF-α、IL-6、CRP、mRS评分均呈负相关(P<0.01)。miR-377、miR-137、TNF-α、IL-6、CRP是老年LI患者神经缺损的影响因素(P<0.01)。miR-377、miR-137联合评估老年LI患者神经缺损的AUC为0.812(95%CI:0.758~0.859),高于二者单一检测(P<0.05,P<0.01)。结论血清miR-377、miR-137水平在老年LI及其神经缺损患者血清中表达较低,检测其水平具有一定临床预测价值。
