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1.
Rare earth elements are applied in China to improve crop production, and the distribution patterns of individual rare earth elements in native plants have widely been reported. But our knowledge is still limited about the dose-dependent accumulation of individual rare earth elements in agricultural crops after application of rare earth elements. Effects of lanthanum and mixtures of rare earth elements were studied in pot experiments on the accumulation of individual rare earth elements in maize plants. All plant samples were divided into plant tops and roots. On addition of mixtures of rare earth elements and lanthanum to the soil, a significant dose-dependent accumulation of individual rare earth element(s) was found in the roots and in the plant tops. Application of mixtures of rare earth elements at >10 mg kg–1 soil, resulted in a significant increase in contents of light rare earth elements in the roots, and at a dose of 50 mg kg–1 soil, a similar phenomenon was found in the plant tops. When mixtures of rare earth elements were replaced by lanthanum alone, at a dose higher than 10 mg La kg–1 soil, a significant increase in La content occurred in the roots and in the plant tops. The content ratio of La to Ce in maize plants appeared to increase as the application doses of rare earth element(s) increased. At a highest dose (50 mg kg–1soil), the transport of the absorbed La from the roots to the plant tops might be substantially reduced after treatment with lanthanum alone, compared with mixtures of rare earth elements. Increasing the application doses of rare earth element(s) appeared to cause a positive Gd and negative Ce anomaly in the roots and in the plant tops, and the anomaly was more obvious in the plant tops than in the roots. The results indicated that the Gd and Ce anomaly in corns might be considered as important parameters for the safety assessment of agricultural application of rare earth elements. 相似文献
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稀土对蚯蚓体内氨基酸含量的影响 总被引:5,自引:1,他引:4
采用滤纸接触染毒法,分别进行了氯化稀土、氯化镧与土居动物蚯蚓接触染毒不同时间和不同浓度的试验。研究其对蚯蚓体内氨基酸含量的影响变化。结果表明。Re、La对蚯蚓体内的氨基酸含量影响较显著,在低浓度时总体表现为促进蚯蚓体内氨基酸的形成,而在高浓度状态下则使蚯蚓体内氨基酸含量下降,产生抑制作用,两种稀土在400mg·L^-1浓度时,蚯蚓体内氨基酸含量除脯氨酸外开始上升,随着作用时间延长,氨基酸含量逐渐下降,在100~1200mg·L^-1浓度范围,两种稀土均引起蚯蚓体内脯氨酸含量的下降,产生抑制作用。 相似文献
3.
Distribution pattern of rare earth elements in fern 总被引:1,自引:0,他引:1
All the lanthanide elements (REE) in fern (Matteuccia) and in soil were determined with inductively coupled plasma mass spectrometer (ICP-MS) in order to discuss REE behavior
in fern. The fern sample was divided into three parts: root, stem, and leaf; the soil of the same site was also sampled and
the soil sample was divided into two parts: HCl and HNO3 soluble part (soil[HCl]) and HF soluble part (soil[HF]). REE in each part was determined by ICP-MS after solvent extraction
separation. The overall variation of the REE pattern of the root does not resemble that of the whole soil, but that of the
HF soluble part. A tetrad effect variation (W-type) was found in the REE patterns of root, stem and leaf; more conspicuous
tetrad effect variation was observed in HREE region than in LREE region, and was so in stem and leaf than in root. Negative
anomalies of Ce were observed in the REE patterns of root, stem and leaf, with bigger anomalies in stem and leaf than in root.
The results of this study suggest that REE in fern has come from silicates of soil and has once been in dissolved state. 相似文献
4.
Concentrations and flux of rare earth elements in a semifield plot as influenced by their agricultural application 总被引:1,自引:0,他引:1
The concentrations of rare earth elements (REs) in atmospheric particles, soil, soil water, surface runoff, and different
parts of corn in an experimental plot in the suburb of Beijing, China were measured and the flux of REs was estimated. The
concentration of REs in air particles with diameter less than 10 μm is 36 ng/m3 and, by ratio analysis, the origin of REs in the atmosphere was likely local soil. The concentration of soluble REs is 0.69
μg/L in rainwater, 5–7 μg/L in surface runoff, as well as 1–4 μg/L in soil water and the application of RE mixture has no
observed influences on their concentrations. The concentration of soluble REs in surface runoff and soil water was dominated
by aqueous-solid-phase partitioning. By estimation of the flux, most of the REs applied will remain in the soil phase and
continued application of REs will cause an accumulation of REs in agricultural soil. 相似文献
5.
E. S. Challaraj Emmanuel V. Vignesh B. Anandkumar S. Maruthamuthu 《Indian journal of microbiology》2011,51(4):488-495
Rare earth elements (REEs) are among the common minerals in the Rare earth environment that are very precious and also enhance
soil properties. The aim of this present study is to evaluate the accumulation of REEs by bacterial isolates of rare earth
environment. Morphological and biochemical characterization were done for 37 bacterial isolates and also molecular studies
were carried out using 16S rRNA sequencing method. The assessment of REEs composition in soil samples of Chavara and Manavalakurichi
analyzed using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) showed the abundance of Cerium and Neodymium among lanthanides.
The bioaccumulation study of rare earth elements by Bacillus cereus were accomplished employing FT-IR spectrum and ICP-OES analysis. The significant accumulation of rare earth elements especially
Cerium and Neodymium was noticed in Bacillus cereus isolated from rare earth environment. 相似文献
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长期喷施稀土对土壤-植物(小麦)系统中稀土元素分布、累积及运移的影响 总被引:16,自引:1,他引:16
在我国施用稀土时间最长的黑龙江省花园农场,研究比较了施用稀土12 a和不施稀土的对照处理上小麦和土壤中的稀土元素的分布、累积及运移.结果表明,长期叶面喷施稀土并未造成耕层土壤和下部土层的稀土元素的累积.成熟期小麦植株各部位的稀土元素含量顺序为根>叶>茎、壳;稀土元素主要累积在根部,其次是叶,茎和壳累积较少.喷施处理小麦根部的稀土元素累积量高于对照,叶部也有此趋势,而茎、壳等部位差异不大.根、茎、叶、壳稀土元素分布模式与土壤中相似,与施用的常乐稀土差别较大;长期喷施稀土未曾造成籽粒中稀土元素的明显累积. 相似文献
8.
Incubation of human erythrocytes with either uranyl ions (UO22+) or rare earth metals (La3+, Nd3+, Sm3+, Eu3+, Tb3+, Dy3+ and Yb3+) at 37°C for 30–45 min resulted in the fusion of erythrocytes. Redistribution of membrane-associated particles was observed using colloidal-iron charge labelling and freeze-fracture electron microscopy. The fusion of erythrocytes induced by these agents, unlike Ca2+, did not exhibit the absolute requirement for phosphate. Moreover, agglutination and fusion by these agents was observed in neuraminidase-treated erythrocytes in contrast to Ca2+- and phosphate-induced fusion. Inhibitors of intrinsic transglutaminase activity partially inhibited (35–45%) the fusion induced by UO22+ suggesting that cross-linking of membrane proteins results in protein-free areas of lipid where fusion may be initiated. 相似文献
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Zhü Weifang Xü Süqin Wü Dongsen Shao Pingping Yang Wenjiao Zhamg Hui Feng Jia 《Biological trace element research》1997,59(1-3):93-98
An ophthalmofunduscope was used to investigate arteriosclerosis among villagers aged 20–40 yr old in two rare earth areas
in Ganzhou, Jiangxi Province. It was noted that the occurrence of arteriosclerosis of the fundus aculi was significantly high
(P < 0.05-0.01), the detection of serum cholesterol (CHO) was remarkably increased (P < 0.01), and the level of IgM was also elevated. However, high-density lipoprotein (HDL) remained at a low level. The effect
of taking rare earth elements (REE) could be direct or indirect, thus causing an increase in cholesterol and interfering with
the synthesis of high-density lipoprotein. Furthermore, rare earth could also cause immunogenic damage to the vascular wall.
All of these could facilitate the formation of arteriosclerosis. 相似文献
12.
用感耦等离子体发射光谱法(ICP-AES)测定了江西赣南地区非稀土矿区和处不同稀土矿区内,土壤-铁芒萁系统中La、Ce、Pr、Nd、Sm、Gy、Db、Yb和Y的含量,并对其在土壤剖面层及铁芒萁植物体内的分布、迁移特征进行了研究.结果表明,土壤剖面层的底土层含量最高,但表土层铈相对富集.稀土元素总量(∑REE)在铁芒萁植物体内的分布规律是叶>根>茎>叶柄,单一稀土元素的分布规律各异,La、Ce、Pr、Nd的分布规律表现为:叶>根>茎>叶柄;Sm和Gd在不同采样点表现为叶>根>茎>叶柄或根>叶>茎>叶柄;Dy、Yb和Y均有3种不同的分布模式:叶>根>茎>叶柄、根>叶>茎>叶柄及根>茎>叶>叶柄.稀土元素在铁芒萁体内的迁移过程中,发生了明显的分馏作用,茎、叶柄、叶中的重稀土相对贫乏. 相似文献
13.
Population growth responses of Tetrahymena shanghaiensis in exposure to rare earth elements 总被引:2,自引:0,他引:2
This article presents the population growth responses of Tetrahymena shanghaiensis s1 in exposure to rare earth elements (REEs). Both the light REEs (La, Sm) and the heavy REEs (Y, Gd) were investigated with
24- and 96-hr population growth assays to evaluate their aquatic toxicity. Four end points, cell count, frequency of neutral
red (NR) uptake, total protein, and nucleic acid content were employed in the 24-h assay, and a population growth curve was
plotted in the 96-h assay. The results of 24- and 96-h assays suggest a dual effect of REEs on T. shanghaiensis of the stimulated growth at low concentrations and the toxicity at higher ones. In the promoted growth of T. shanghaiensis, however, the cell density increased with an increased growth rate and the protein and nucleic acid content per 104 cells undertook no remarkable changes, which suggests possible cell growth control by REE. 相似文献
14.
感耦等离子体发射光谱法研究土壤—铁芒萁系统中稀土元素的分布、累积和迁移特征 总被引:8,自引:2,他引:8
用感耦等离子体发射光谱法(ICP-AES)测定了东西赣南地区非稀土矿区和4处不同稀土矿区内,土壤-铁芒萁系统中La、Ce、Pr、Nd、Sm、Gd、Dy、Yb和Y的含量,并对其在土壤剖面层及铁芒萁植物体内的分布、迁移特征进行了研究,结果表明,土训层的底土层含量最高,但表土层铈相对富集、稀土元素总量(∑REE)在铁芒萁植物体内的分布规律是叶>根>茎>叶柄,单一稀土的分布规律各异,La、Ce、Pr、Nd的分布规律表现为:叶>根>茎>叶柄;Sm和Gd在不同采样点表现为叶>根>茎>叶柄或根>叶>茎>叶柄;Dy、Yb和Y均有3种不同的分布模式:叶>根>茎>叶柄、根>叶>茎>叶柄及根>茎>叶>叶柄,稀土元素在铁芒萁体内的迁移过程中,发生了明显的分馏作用,茎、叶柄、叶中的重稀土相对贫乏。 相似文献
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Yu-Min Song Jun-Peng Xu Qian Hou Zao-Long Zhu 《Journal of inorganic biochemistry》2009,103(3):396-400
Three new solid complexes have been synthesized by the reaction of rare earth(III) nitrate with the first ligand curcumin (HL) and the second ligand 1,10-phenanthroline-5,6-dione (L′) in alcohol solution (pH = 6.5-7.0). The composition of the complexes has been characterized by elemental analysis, molar conductivity, thermogravimetric analysis, IR, UV-vis methods. The results reveal that β-diketone group of the first ligand to coordinates with rare earth ions in bidentate mode after deprotonated. But the second ligand uses its two N atoms coordinates with rare earth ions in bidentate mode. The general formula of the complexes is REL3L′ (RE = Sm, Eu, Dy). The results of antibacterial activity indicated that the complexes have excellent antibacterial ability for the testing bacterium than that of curcumin. The result of agarose gel electrophoresis suggested that the complex of SmL3L′ can cleave the plasmid DNA at physiological pH and temperature. And it was found that the cleavage process of plasmid DNA was sensitive to pH, however, adding radical scavengers almost had no effect on the DNA cleavage reaction, therefore, the cleavage of DNA by SmL3L′ does not produce diffusible hydroxyl radicals via the Fenton reaction. 相似文献
17.
稀土元素对植物的生物效应及其作用机理 总被引:48,自引:0,他引:48
综述了稀土元素对植物根系发育、生物量、品质和抗逆性的影响.适量稀土浓度可促进植物生长,提高种子萌发能力和根系发育,提高植物生物量,并改善植物果实的品质.施用适量稀土元素还可以增强植物的抗逆性并且对一些植物病害有一定防治作用.介绍了植物对稀土元素的吸收特性和稀土元素在植物体内的含量、分布、存在形式及细胞定位.重点探讨了稀土元素对植物光合作用、叶绿素形成、植物吸收营养元素、稀土元素与钙相关性和稀土元素对细胞膜及酶的作用机理,内容包括稀土元素可提高植物叶绿素含量,增强光合效率,从而增加植物生物量.适量的稀土元素能够促进植物对营养元素的吸收、转化和利用.稀土元素有类似钙的功能,可置换出酶中的钙离子而参与酶的反应.稀土离子可以维持细胞膜的透性和稳定性,提高膜的保护功能,增强植物对不良环境的抵御能力.最后,对稀土元素的研究前景进行了展望. 相似文献
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The homo-dinuclear heteroleptic phthalocyaninato-[2,3,9,10,16,17,23,24-octakis(octyloxy)phthalocyaninato] rare earth(III) triple-decker complexes (Pc)M[Pc(OC8H17)8]M[Pc(OC8H17)8] (M=Pr, Nd, Sm, Eu, Tb, Dy, Y, Ho, Er, Tm) (1a–10a) and (Pc)M[Pc(OC8H17)8]M(Pc) (M=Nd, Sm, Eu, Tb, Dy, Y, Ho, Er, Tm) (2b–10b) were obtained by condensation of bis(phthalocyaninato) rare earths M[Pc(OC8H17)8]2 (M=Pr, Nd, Sm, Eu, Tb, Dy, Y, Ho, Er, Tm), Li2(Pc) and M(acac)3·nH2O (M=Pr, Nd, Sm, Eu, Tb, Dy, Y, Ho, Er, Tm). These novel compounds were characterized by 1H NMR, mass, electronic absorption (UV–Vis), and IR spectroscopic methods. 相似文献
20.
稀土元素对农田生态系统的影响研究进展 总被引:7,自引:0,他引:7
稀土矿的开采和冶炼、稀土农用等导致农田土壤稀土元素含量不断积累,对农田生态系统结构和功能稳定产生严重的影响。综述了近20年来国内外农田生态系统稀土元素的主要来源、分配和输出,土壤和植物中稀土元素的测定方法,稀土元素对农田生态系统中植物、微生物、动物以及人类健康影响的研究进展。探讨了农田生态系统稀土元素的毒性评价和稀土污染土壤的修复措施。最后提出开展稀土元素对农田生态系统影响研究还需要加强的一些问题。 相似文献