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排序方式: 共有532条查询结果,搜索用时 11 毫秒
1.
Alexander N. Shikov Ekaterina D. Obluchinskaya Elena V. Flisyuk Inna I. Terninko Yulia E. Generalova Olga N. Pozharitskaya 《Marine drugs》2022,20(5)
In recent years, natural deep eutectic solvents (NADES) have been widely investigated for the extraction of food and medicinal plants as well as seaweeds. However, the ability of NADES for trace elements co-extraction from natural sources is not well investigated. The aim of this study was to investigate the ability of common NADES for trace elements co-extraction from Fucus vesiculosus. All of the tested NADES did not recover As and Co (concentration <LOQ). Moreover, all of the tested NADES provided a low recovery (<9%) of Ba, Ca, Fe, Mg, Mn, Sr, and Zn. The method of extraction had not shown a statistically significant effect on the co-extraction of all elements (excluding Ba and Ca). In contrast, the water content in NADES was significantly affected on the recovery of Ba, Ca, Mg, Mn, Sr, and Zn. The recovery of Al and Cr was relatively high and considerably varied (from 1.5 to 59.9%). NADES comprising lactic acid:glucose:H2O (5:3:1) provided the lowest contents of all elements, and the highest extracted amounts were obtained employing water contents of 60–80%. The calculated daily intake of all the elements contained in NADES extracts were less than the daily dose risk estimators. The hazard quotients, hazard indexes, and carcinogenic risk calculated for all trace elements and their combination were considerably less than 1. This evidences no health risk, and carcinogenic risk after topical application of all studied NADES. For the first time, the results of the current study demonstrated that NADES extracts of F. vesiculosus contain a lower amount of trace metals and are safer than the extracts obtained with water and 70% acetone. This indicates a significant advantage for NADES compared with the other solvents. 相似文献
2.
辽宁省海城地区2011年突发的杨树烂皮病,危害严重,面积达2549hm2,阐述了杨树烂皮病发生危害情况,分析了突发原因,提出了防治对策。 相似文献
3.
利用多时相,多平台卫星遥感数据,对四川省泸定县磨西台地的地质灾害开展了遥感监测.研究了地质灾害的发展演化趋势,判定了地质灾害的稳定性,为磨西台地的地质灾害防治提供了科学依据.遥感监测显示,自2006年1月2日至2009年12月21日的近4 a,磨西台地内无新发生泥石流和崩塌灾害,原已发生的泥石流和崩塌也未见明显复发,泥石流处于停歇期,崩塌处于稳定状态.大部分滑坡处于稳定状态,只有1处新发生的滑坡还在发展之中,处于不稳定状态,存在进一步发展的可能,需进一步加强监测.磨西台地岸坡的冲蚀滑塌和浅层流滑则一直在持续发展,对磨西台地岸坡的稳定构成威胁,并造成磨西台地面积的缩小,需要及时治理. 相似文献
4.
生态风险评价是目前环境科学领域的研究重点,而水土流失问题是造成生态风险的主要因素.以生态风险评估理论研究为基础,将该体系按照生态危险性、生态重要性和生态易损性3部分进行分析,以北京市的遥感影像为数据源,同时结合GIS手段,选取多指标,综合分析北京生态风险等级分布,并对各指标因素进行打分,最终得到北京地区生态风险评估图.结果表明:在人口密集区域,由于其与人类活动息息相关,有较高的生态风险等级;总体上看,北京山区北部的生态风险等级要高于南部,西部要高于东部;具有相同生态风险等级的各区域主要风险源不同,但总体上相近地区的主要风险源相同.基于早期的生态风险评估理论,将水土流失问题作为研究重点,克服传统的单因子评价、综合指数评价和生态风险指数评价的不足,构建一种新的生态风险评估方法,为生态风险评估提供参考依据. 相似文献
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《Journal Of Aquatic Food Product Technology》2013,22(3):103-106
No abstract available for this article. 相似文献
9.
N. R. Atkinson S. D. Young A. M. Tye N. Breward E. H. Bailey 《Soil Use and Management》2012,28(4):559-570
Urban waste disposal occurred on fenland to the west of Manchester, England, between 1900 and 1964. The reclaimed fenland, Chat Moss, is now used for mixed arable farming. A total of 1.92 Mt of waste including privy midden, street sweepings, clinkers and slaughterhouse refuse was incorporated into the moss resulting in a modified topsoil with raised pH and reduced organic matter content compared with the subsoil. Elevated levels of potentially toxic elements (PTEs) are observed in the topsoil beyond the typical depth of atmospheric contamination; Cd and As concentrations exceed soil guideline values (SGVs) at 1.8 and 43 mg/kg, respectively. Sequential extraction indicates that waste‐derived Pb, Zn and Ni remain predominantly in the residual fraction, whereas Cu was mainly organically bound. Arsenic was predominately found in oxide and organic matter fractions with Cd in carbonate, oxide, organic matter and residual fractions. Pot trials indicated limited uptake of PTEs by vegetables grown on the waste‐amended soil, with the exception of Cd uptake by lettuce (0.22 mg/kg FW) and Pb uptake by radish (0.16 mg/kg FW), which exceeded current EU limits of 0.2 and 0.1 mg/kg FW, respectively. Hazard quotients (HQs) identified no risks to adults from consumption of vegetables grown in these soils with the exception of lettuce consumption with a HQ of 1.4. Risks to children were slightly greater with HQs >1 for Cd in lettuce, spinach, carrots and onion, As in lettuce, parsley and onion and for Zn in spinach. 相似文献
10.
Spinosad is a reduced-risk insecticide with a novel mode of action that provides an alternative to older classes of insecticides such as organophosphates, carbamates and pyrethroids. A comprehensive ecological risk assessment for spinosad use in US cotton crops is presented within a framework of tiered levels of refinement following the guidelines of the US EPA for ecological risk assessments. Toxicity information for a variety of species is documented and utilized, environmental concentrations estimated, and risk characterizations in the form of risk quotients are quantified. Results indicate that spinosad use in cotton does not exceed the most conservative Tier I levels of concern (LOC) values for groundwater, mammals and birds or acute risk to aquatic organisms. Use of very conservative Tier I screening methods resulted in exceeding LOC values for chronic exposure for some aquatic organisms, thus prompting further refinement. When the exposure prediction was refined using less conservative, Tier II mechanistic environmental fate transport models to predict offsite transport and environmental concentrations, chronic risk was not predicted for these species. Spinosad is acutely toxic to bees under laboratory conditions, but toxicity of residue studies and field studies indicate that under actual use conditions the impact on bees is minimal. 相似文献