Increasing levels of pollution within water bodies can cause eutrophication and an associated rapid growth in and reproduction of phytoplankton. Although most frequently occurring in bodies of water such as lakes and ...Increasing levels of pollution within water bodies can cause eutrophication and an associated rapid growth in and reproduction of phytoplankton. Although most frequently occurring in bodies of water such as lakes and dams, in recent years an increasing number of river systems in China have suffered serious algal blooms. The community structure of phytoplankton may differ, however, dependent on the hydrodynamic conditions and nutrient levels within the water body. The field investigation results obtained from a stagnant river in Suzhou City and Taihu Lake, China, showed that in water with higher concentrations of nitrogen and phosphorus, Chlorophyta became the predominant species and in water with lower concentrations of nitrogen and phosphorus, Cyanobacteria became the predominant species. Growth experiments with competitive species, Microcystis aeruginosa Kutz and Scenedesmus quadricauda （Turp.）, were conducted at three different nutrient levels. The biomass of algae in pure and mixed cultures was measured under conditions of different N/P ratios at oligotrophic, eutrophic and hypertrophic nutrient levels. The results indicated that the most suitable state for the growth and reproduction of M. aeruginosa and S. quadricauda were eutrophic conditions in both pure and mixed cultures. Under competition, however, the lower medium nutrient levels favoured M. aeruginosa, while the higher medium nutrient levels better suited S. quadricauda. Under similar hydrodynamic conditions, the community structure of phytoplankton in the water body was determined by the dominant species in competition for nutrients.展开更多
Since the impoundment of the Three Gorges Reservoir(TGR), the riparian zone has been subjected to numerous environmental changes. This study was conducted to recognize the distribution of grass roots and its impacts o...Since the impoundment of the Three Gorges Reservoir(TGR), the riparian zone has been subjected to numerous environmental changes. This study was conducted to recognize the distribution of grass roots and its impacts on soil nutrients in the water level fluctuation zone of TGR. Roots of four predominant herbaceous plants in the study area, specifically, Cynodon dactylon, Hemarthria altissima, Hemarthria compressa, and Paspalum paspaloides, and their corresponding relation with soil nutrient contents were investigated. Root surface area density was determined with Win RHIZO, and the relationships of root distribution with soil depths and soil nutrient contents were studied. The results indicates that most roots are distributed in the top soil layer of 0-10 cm. Estimated root surface area density for the selected grass species ranges from 0.16 to 13.44 cm^2/cm^3, and decreases exponentially with an increase in soil depth. Soil organic matter and total nitrogen contents are significantly lower on bare control area than the corresponding values on the grasslands. Total nutrient contents on grasslands of C. dactylon and H. compressa are higher than those of other grass areas. Root length density and root surface area density are significantly correlated with soil organic matter and total nitrogen content for the four grasslands. The present results suggests that plant roots have significant effects on the distribution of soil nutrients in soil profiles in the riparian zone along the TGR. Nevertheless, additional investigations are needed to reveal the specific interactions between plant roots distribution, soil nutrients and water level fluctuations.展开更多
Ruxi River is a tributary of the Three Gorges Reservoir. This study examined the temporal and spatial dynamics in particle size characteristics and the associated nutrients and contaminants of the fluvial suspended an...Ruxi River is a tributary of the Three Gorges Reservoir. This study examined the temporal and spatial dynamics in particle size characteristics and the associated nutrients and contaminants of the fluvial suspended and deposited sediments along the Ruxi River. Temporal variations in the particle size distribution of the suspended sediment are controlled mainly by differences in sediment source during different seasons. Total organic carbon （TOC）, total nitrogen （TN） and total phosphorous （TP） in the 〈 62 μm fraction of the suspended sediment exhibit considerably higher concentrations in spring, indicating high probability of algal blooms in the backwater areas. Downstream trends in the nutrient contents of 〈 62 pm deposited sediments imply the greatest potential for eutrophication in the backwater ends, where highest nutrient concentrations were detected. Assessment of metal contamination shows that the sediments deposited in the water-level fluctuation zone were moderately to strongly contaminated by Cadmium （Cd）, with a considerably high potential ecological risk. The findings reported have emphasized the impacts of reservoir impoundment on aquatic and/or terrestrial environment in this region. More information on physical, chemical and biological processes of sediment and sediment-associated materials are needed for developing ecologically sound policies management. environmentally and of water and sediment展开更多
目的系统分析目前我国膳食营养素参考摄入量(dietary reference intakes,DRIs)制定的现况及我国与全球DRIs制定的异同,为规范我国DRIs的制定提供合理的参考建议。方法计算机检索PubMed、ISI Web of Knowledge、he Cochrane Library、CBM...目的系统分析目前我国膳食营养素参考摄入量(dietary reference intakes,DRIs)制定的现况及我国与全球DRIs制定的异同,为规范我国DRIs的制定提供合理的参考建议。方法计算机检索PubMed、ISI Web of Knowledge、he Cochrane Library、CBM、WanFang Data、CNKI、VIP等数据库,检索时限均为建库至2013年5月31日。按照纳入与排除标准选择文献和提取数据,采用描述性分析方法系统评价文献的基本信息、不同营养素DRIs的制定及不同年龄段的分布情况。结果初检获得文献588篇,最终纳入42篇,包括14篇指南、12篇系统评价及16篇原始研究文献。结果显示,WHO指南及全球系统评价研究主要关注的营养素是铁及脂溶性维生素(维生素A、D);我国除关注铁及维生素A外,还关注蛋白质、钙、锌、硒。纳入指南关注的人群主要是3～18岁及孕妇,而系统评价除关注此两类人群外,还关注>18岁的成年人。我国对各类人群均有研究,但主要关注18～45岁成年人和6～12岁学龄儿童。纳入的16个原始研究中,4个关注男性,2个关注女性。结论我国DRIs的制定及研究目前尚处于急需更新补充的状态。作为最大的发展中国家,我国的疾病负担、消费水平、膳食模式、膳食营养素的提供内容及保障水平均有别于发达国家和其他发展中国家。制定我国DRIs时宜在循证评价全球现有DRIs的基础上,借鉴当前可得的最佳DRIs标准、方法和证据,并结合我国实际国情、疾病负担及专家意见,循证制定既能满足我国人民健康需要又适合我国国情的DRIs。展开更多
The main purpose of the study was to reveal the hypoglycemic effect of a combination of some selected spices along with the evaluation of nutritional values. A sum of fourteen different types of spices at different pe...The main purpose of the study was to reveal the hypoglycemic effect of a combination of some selected spices along with the evaluation of nutritional values. A sum of fourteen different types of spices at different percentages were taken into consideration to propel the research activities forward, viz;ginger, garlic, onion, red chili, turmeric, cumin, cinnamon, clove, coriander, fenugreek, black pepper, nigella, carom seed and cardamom. The healthy experimental wistar albino rats were made diabetic by injecting alloxan monohydrate intraperitoneally a dose of 150 mg/kg body weight. The rats of Group-D and Group-E were treated with the sample, mixed spices at a dose of 100 mg/kg and 200 mg/kg body weight respectively with the lab diet while in case of Group-C, glibenclamide at a dose of 0.5 mg/kg body weight was introduced with the lab diet for a total period of 21 days where as for the same days span, Group-A and Group-B were continued feeding with only lab diet. Data suggest that the mixed spices of both doses applied in Group-D and Group-E had exerted effects significantly (p 0.05) in lowering the blood glucose level. On 22nd day, in Group-D and Group-E, the FBG level was found to be reduced by around 40.66% and 41.18% respectively compared to their respective initial days where in Group-C, the reduction was around 51.90% in comparison to its initial day. Again, in case of 2hPG level measurement, on 22nd day, both the groups, Group-D and Group-E were found with the decreased level of around 19.38% and 39.11% respectively compared to their respective initial days while the Group-C was shown with the reduced of 44.26% in comparison adopting same manner. Furthermore, various analyses confirm the presence of several micro and macro nutrients and high amount of dietary fiber in the spices mix. Thus the result affirms that this combined spice possesses strong hypoglycemic properties.展开更多
基金supported by the Natural Science Foundation of Jiangsu Province (No.BK2006710) the Hi-Tech Research and Development Program (863) of China (No:2003AA601100)
文摘Increasing levels of pollution within water bodies can cause eutrophication and an associated rapid growth in and reproduction of phytoplankton. Although most frequently occurring in bodies of water such as lakes and dams, in recent years an increasing number of river systems in China have suffered serious algal blooms. The community structure of phytoplankton may differ, however, dependent on the hydrodynamic conditions and nutrient levels within the water body. The field investigation results obtained from a stagnant river in Suzhou City and Taihu Lake, China, showed that in water with higher concentrations of nitrogen and phosphorus, Chlorophyta became the predominant species and in water with lower concentrations of nitrogen and phosphorus, Cyanobacteria became the predominant species. Growth experiments with competitive species, Microcystis aeruginosa Kutz and Scenedesmus quadricauda （Turp.）, were conducted at three different nutrient levels. The biomass of algae in pure and mixed cultures was measured under conditions of different N/P ratios at oligotrophic, eutrophic and hypertrophic nutrient levels. The results indicated that the most suitable state for the growth and reproduction of M. aeruginosa and S. quadricauda were eutrophic conditions in both pure and mixed cultures. Under competition, however, the lower medium nutrient levels favoured M. aeruginosa, while the higher medium nutrient levels better suited S. quadricauda. Under similar hydrodynamic conditions, the community structure of phytoplankton in the water body was determined by the dominant species in competition for nutrients.
基金the National Natural Science Foundation of China (Grant Nos.41601296,41571278 and 41771321)China Postdoctoral Science Foundation (Grant No.2016M592720)+1 种基金Applied Basic Research Foundation of Yunnan Province (Grant No.2016FD011)Sichuan Science and Technology Program (2018SZ0132)
文摘Since the impoundment of the Three Gorges Reservoir(TGR), the riparian zone has been subjected to numerous environmental changes. This study was conducted to recognize the distribution of grass roots and its impacts on soil nutrients in the water level fluctuation zone of TGR. Roots of four predominant herbaceous plants in the study area, specifically, Cynodon dactylon, Hemarthria altissima, Hemarthria compressa, and Paspalum paspaloides, and their corresponding relation with soil nutrient contents were investigated. Root surface area density was determined with Win RHIZO, and the relationships of root distribution with soil depths and soil nutrient contents were studied. The results indicates that most roots are distributed in the top soil layer of 0-10 cm. Estimated root surface area density for the selected grass species ranges from 0.16 to 13.44 cm^2/cm^3, and decreases exponentially with an increase in soil depth. Soil organic matter and total nitrogen contents are significantly lower on bare control area than the corresponding values on the grasslands. Total nutrient contents on grasslands of C. dactylon and H. compressa are higher than those of other grass areas. Root length density and root surface area density are significantly correlated with soil organic matter and total nitrogen content for the four grasslands. The present results suggests that plant roots have significant effects on the distribution of soil nutrients in soil profiles in the riparian zone along the TGR. Nevertheless, additional investigations are needed to reveal the specific interactions between plant roots distribution, soil nutrients and water level fluctuations.
基金financially supported by the National Natural Science Foundation of China (41430750, 41301293)the National Key R&D Program of China (2017YFD0800505, 2016YFC0402301)
文摘Ruxi River is a tributary of the Three Gorges Reservoir. This study examined the temporal and spatial dynamics in particle size characteristics and the associated nutrients and contaminants of the fluvial suspended and deposited sediments along the Ruxi River. Temporal variations in the particle size distribution of the suspended sediment are controlled mainly by differences in sediment source during different seasons. Total organic carbon （TOC）, total nitrogen （TN） and total phosphorous （TP） in the 〈 62 μm fraction of the suspended sediment exhibit considerably higher concentrations in spring, indicating high probability of algal blooms in the backwater areas. Downstream trends in the nutrient contents of 〈 62 pm deposited sediments imply the greatest potential for eutrophication in the backwater ends, where highest nutrient concentrations were detected. Assessment of metal contamination shows that the sediments deposited in the water-level fluctuation zone were moderately to strongly contaminated by Cadmium （Cd）, with a considerably high potential ecological risk. The findings reported have emphasized the impacts of reservoir impoundment on aquatic and/or terrestrial environment in this region. More information on physical, chemical and biological processes of sediment and sediment-associated materials are needed for developing ecologically sound policies management. environmentally and of water and sediment
文摘目的系统分析目前我国膳食营养素参考摄入量(dietary reference intakes,DRIs)制定的现况及我国与全球DRIs制定的异同,为规范我国DRIs的制定提供合理的参考建议。方法计算机检索PubMed、ISI Web of Knowledge、he Cochrane Library、CBM、WanFang Data、CNKI、VIP等数据库,检索时限均为建库至2013年5月31日。按照纳入与排除标准选择文献和提取数据,采用描述性分析方法系统评价文献的基本信息、不同营养素DRIs的制定及不同年龄段的分布情况。结果初检获得文献588篇,最终纳入42篇,包括14篇指南、12篇系统评价及16篇原始研究文献。结果显示,WHO指南及全球系统评价研究主要关注的营养素是铁及脂溶性维生素(维生素A、D);我国除关注铁及维生素A外,还关注蛋白质、钙、锌、硒。纳入指南关注的人群主要是3～18岁及孕妇,而系统评价除关注此两类人群外,还关注>18岁的成年人。我国对各类人群均有研究,但主要关注18～45岁成年人和6～12岁学龄儿童。纳入的16个原始研究中,4个关注男性,2个关注女性。结论我国DRIs的制定及研究目前尚处于急需更新补充的状态。作为最大的发展中国家,我国的疾病负担、消费水平、膳食模式、膳食营养素的提供内容及保障水平均有别于发达国家和其他发展中国家。制定我国DRIs时宜在循证评价全球现有DRIs的基础上,借鉴当前可得的最佳DRIs标准、方法和证据,并结合我国实际国情、疾病负担及专家意见,循证制定既能满足我国人民健康需要又适合我国国情的DRIs。
文摘The main purpose of the study was to reveal the hypoglycemic effect of a combination of some selected spices along with the evaluation of nutritional values. A sum of fourteen different types of spices at different percentages were taken into consideration to propel the research activities forward, viz;ginger, garlic, onion, red chili, turmeric, cumin, cinnamon, clove, coriander, fenugreek, black pepper, nigella, carom seed and cardamom. The healthy experimental wistar albino rats were made diabetic by injecting alloxan monohydrate intraperitoneally a dose of 150 mg/kg body weight. The rats of Group-D and Group-E were treated with the sample, mixed spices at a dose of 100 mg/kg and 200 mg/kg body weight respectively with the lab diet while in case of Group-C, glibenclamide at a dose of 0.5 mg/kg body weight was introduced with the lab diet for a total period of 21 days where as for the same days span, Group-A and Group-B were continued feeding with only lab diet. Data suggest that the mixed spices of both doses applied in Group-D and Group-E had exerted effects significantly (p 0.05) in lowering the blood glucose level. On 22nd day, in Group-D and Group-E, the FBG level was found to be reduced by around 40.66% and 41.18% respectively compared to their respective initial days where in Group-C, the reduction was around 51.90% in comparison to its initial day. Again, in case of 2hPG level measurement, on 22nd day, both the groups, Group-D and Group-E were found with the decreased level of around 19.38% and 39.11% respectively compared to their respective initial days while the Group-C was shown with the reduced of 44.26% in comparison adopting same manner. Furthermore, various analyses confirm the presence of several micro and macro nutrients and high amount of dietary fiber in the spices mix. Thus the result affirms that this combined spice possesses strong hypoglycemic properties.
