Characterization and bacterial toxicity of lanthanum oxide bulk and nanoparticles

Balusamy, Brabu; Kandhasamy, Yamuna Gowri; Anitha, S.; Gopalakrishnan, C.; Subramanian, Murugan Siva; Kumaravel, T. S.

doi:10.1016/s1002-0721(12)60224-5

Cited by 76 publications

(33 citation statements)

References 27 publications

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“…La compounds show antibacterial activity with respect to many organisms, including gram-positive ones, but not to gram-negative organisms which have thick and low-permeable cell walls (Balusamy et al, 2012). Gram-negative bacteria are Fig.…”

Section: Discussionmentioning

confidence: 99%

Main minerals of abnormally high-grade ores of the Tomtor deposit (Arctic Siberia)

Лазарева

Жмодик

Добрецов

et al. 2015

Russian Geology and Geophysics

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The Tomtor massif of Paleozoic ultramafic alkaline rocks and carbonatites is located in the northern part of the Sakha Republic (Yakutia). The massif (its total area is ~250 km 2 ) is ~20 km in diameter, with a rounded shape and a concentrically zoned structure. The core of the massif consists of carbonatites surrounded by a discontinuous ring of ultramafic rocks and foidolites. The outer part is composed of alkali and nepheline syenites. All rocks are weathered and covered with eluvium, which is the thickest after carbonatites enriched in phosphates and REE. The weathering profile consists of four layers, from the top: kaolinite-crandallite, siderite, goethite, and francolite. The highest-grade ores are observed in the bedded deposit which fills depressions in "sagging" eluvium. The ores are laminated and cryptogranular, with high Nb, Y, Sc, and REE contents (on average, 4.5% Nb 2 O 5 , 7-10% REE 2 O 3 , 0.75% Y 2 O 3 , and 0.06% Sc 2 O 3 ). The highest-grade ores are natural Nb and REE concentrates. The total REE content in some layers is >10%. The morphologic features of the highest-grade phosphate ores from the northern part of the Burannyi site were studied. The ore-forming minerals belong to the pyrochlore group, crandallite group (goyazite), and monazite-Ce. The pyrochlore group minerals occur mainly as crystals that were completely replaced by barium-strontium pyrochlore and/or plumbopyrochlore but retained the original faces; also, they occur as numerous conchoidal fragments. The grains of the pyrochlore group minerals sometimes have a zonal structure, with an unaltered pyrochlore core and a reaction rim. Goyazite occurs predominantly as colloform grains. According to SEM and TEM data, monazite occurs in the ores as ~50 nm particles, which cover the outer part of halloysite tubes (800-3000 nm long and 300 nm in diameter) as a dense layer and make up peculiar biomorphic aggregates. The mineralogical data, the occurrence of biomorphic aggregates, and the close association of organic remains with ore minerals suggest that the high-grade ores of the Tomtor deposit, including the Burannyi site, resulted from a hydrothermal-sedimentary process with a presumably important role of bioaccumulation of REE phosphates.

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Section: Discussionmentioning

confidence: 99%

Main minerals of abnormally high-grade ores of the Tomtor deposit (Arctic Siberia)

Лазарева

Жмодик

Добрецов

et al. 2015

Russian Geology and Geophysics

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“…Gd 2 O 3 NPs may replace the Gd-chelates currently used as contrast agents in magnetic resonance imaging due to their higher performance [7]. In addition, La 2 O 3 NPs [8] CeO 2 NPs [9][10][11], Gd 2 O 3 NPs [12], and Tb-based [13] and Ln-doped NPs [14] also have potential as antimicrobials.…”

Section: Introductionmentioning

confidence: 99%

Potential Hazard of Lanthanides and Lanthanide-Based Nanoparticles to Aquatic Ecosystems: Data Gaps, Challenges and Future Research Needs Derived from Bibliometric Analysis

et al. 2020

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Lanthanides (Ln), applied mostly in the form of nanoparticles (NPs), are critical to emerging high-tech and green energy industries due to their distinct physicochemical properties. The resulting anthropogenic input of Ln and Ln-based NPs into aquatic environment might create a problem of emerging contaminants. Thus, information on the biological effects of Ln and Ln-based NPs is urgently needed for relevant environmental risk assessment. In this mini-review, we made a bibliometric survey on existing scientific literature with the main aim of identifying the most important data gaps on Ln and Ln-based nanoparticles’ toxicity to aquatic biota. We report that the most studied Ln for ecotoxicity are Ce and Ln, whereas practically no information was found for Nd, Tb, Tm, and Yb. We also discuss the challenges of the research on Ln ecotoxicity, such as relevance of nominal versus bioavailable concentrations of Ln, and point out future research needs (long-term toxicity to aquatic biota and toxic effects of Ln to bottom-dwelling species).

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“…not bioavailable) in soils. 14,15 However, recent laboratory studies show the potential for both toxicity and bioaccumulation of REEs in many species, including microorganisms and phytoplankton, [16][17][18] aquatic plants, 5,19 terrestrial plants, [20][21][22][23][24] terrestrial and aquatic invertebrates, 1, 10, 13, 25 as well as in fish. [26][27][28] Anthropogenic REE enrichment, and subsequent bioaccumulation in biota, may therefore lead to REE concentrations closer to estimated toxicity thresholds, as is the case in the Yellow River region in China.…”

Section: Introductionmentioning

confidence: 99%

Rare earth elements (REE) in freshwater, marine, and terrestrial ecosystems in the eastern Canadian Arctic

MacMillan

Chételat

Heath

et al. 2017

Preprint

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Few ecotoxicological studies exist for rare earth elements (REEs), particularly fieldbased studies on their bioaccumulation and food web dynamics. REE mining has led to significant environment impacts in several countries (China, Brazil, U.S.), yet little is known about the fate and transport of these contaminants of emerging concern. To understand how REEs behave in pristine northern food webs, we measured REE concentrations and carbon and nitrogen stable isotope ratios (∂ 15 N, ∂ 13 C) in biota from marine, freshwater, and terrestrial ecosystems of the eastern Canadian Arctic (N=339). Northern ecosystems are potentially vulnerable to REE enrichment from prospective mining projects at high latitudes. Wildlife harvesting and tissue sampling was partly conducted by local hunters through a communitybased monitoring project. Results show that REE generally follow a coherent bioaccumulation pattern for sample tissues, with some anomalies for redox-sensitive elements (Ce, Eu). Highest REE concentrations were found at low trophic levels, especially in vegetation and aquatic invertebrates. Terrestrial herbivores, ringed seal, and fish had low REE levels in muscle tissue (<0.1 nmolg -1 ), yet accumulation was an order of magnitude higher in all liver tissues. Age-and length-dependent REE accumulation also suggest that REE uptake is faster than elimination for some species. Overall, REE bioaccumulation patterns appear to be species-and tissue-species, with limited potential for biomagnification. This study provides novel ecotoxicological data on the behaviour of REE in ecosystems and will be useful for environmental impact assessment of REE enrichment in northern regions.peer-reviewed)

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Characterization and bacterial toxicity of lanthanum oxide bulk and nanoparticles

Cited by 76 publications

References 27 publications

Main minerals of abnormally high-grade ores of the Tomtor deposit (Arctic Siberia)

Main minerals of abnormally high-grade ores of the Tomtor deposit (Arctic Siberia)

Potential Hazard of Lanthanides and Lanthanide-Based Nanoparticles to Aquatic Ecosystems: Data Gaps, Challenges and Future Research Needs Derived from Bibliometric Analysis

Rare earth elements (REE) in freshwater, marine, and terrestrial ecosystems in the eastern Canadian Arctic

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