The Importance of Organic Compounds on the Modbilization and Bioassimilation of Thorium in the Morro do Ferro Environment

1984 ◽  
Vol 44 ◽  
Author(s):  
N. Miekeley ◽  
R. M. Dotto ◽  
I. L. Kuchler ◽  
P. Linsalata
Keyword(s):  
Organic Compounds ◽  
Chelating Agents ◽  
Light Rare Earth ◽  
Indigenous Plants ◽  
Naturally Occurring ◽  
Weathered Soil ◽  
Concentration Factors ◽  
High Concentrations ◽  
Light Rare Earth Elements

AbstractData are presented on the role of naturally occurring and synthetic organic compounds in the mobilization and bicassimilation of Th-232. The study is taking place in the state of Minas Gerais, Brazil, in and around an exposod and deeply weathered are body (the Morro do Ferro) estimated to contain 30,000 tonnes of Th and > 100,000 tonnes of the light rare earth elements. Indigenous plants collected from the are body surface are shown to contain high concentrations in the range of 20–1,000 μg/g ash of Th-232. Prcliminary estimates of Th-232 concentration factors range between 10−5 and 10−3 and are comparable with those reported for plutonium. Leaching studies using different chelating agents indicate that the release of Th-232 from. weathered soil and are as well as plant uptake are directly related to complex stability. Preliminary results of speciation studies using ultrafiltration techniques indicate that for water which has percolated through the are body, most of the dissolved Th-232 is associated with colloidal humic acids of molecular weight > 300,000.

scholarly journals Petrology and Geochemical Features of Semporna Volcanic Rocks, South-east Sabah, Malaysia

2021 ◽  
Vol 50 (1) ◽  
pp. 9-21
Author(s):  
Elvaene James ◽  
Azman Abdul Ghani ◽  
Oluwatoyin O. Akinola ◽  
Junaidi Asis
Keyword(s):  
Volcanic Rocks ◽  
Geochemical Data ◽  
Magma Source ◽  
Light Rare Earth ◽  
Calc Alkaline ◽  
Ce Anomaly ◽  
Arc Setting ◽  
A Minor ◽  
Light Rare Earth Elements

The volcanic rocks in Semporna Peninsula, Sabah, Malaysia forms parts of the Miocene subjected slab during the Miocene-Pliocene orogeny. This study presents new petrographic and geochemical data of volcanic rocks in Semporna area. The volcanic rocks range in composition from basaltic andesite, andesite, dacite to rhyolite, with most of the volcanic shows calc-alkaline affinity with a minor tholeiitic feature. The trace elements shows enrichment in large-ion lithophile elements (LILE) and light rare earth elements (LREE) suggesting that the volcanic rocks have similar geochemical patterns and might come from similar magma source. The petrochemical data suggests that volcanic rocks of Semporna shows characteristic of subduction zone (negative Nb, Ta, and Ti). Decreasing magnitude of Europium anomalies from intermediate to acid lavas suggests an important role of plagioclase in the fractional crystallization. Negative Ce anomaly in part of Semporna volcanic rocks suggest that those volcanic rocks may related with emergence of oxygenated deep-sea environment. Tectonic diagrams showed that the Semporna volcanic rocks were formed in an island arc setting.

scholarly journals Li-Co–Ni-Mn-(REE) veins of the Western Erzgebirge, Germany—a potential source of battery raw materials

2021 ◽  
Author(s):  
Mathias Burisch ◽  
Max Frenzel ◽  
Henning Seibel ◽  
Albert Gruber ◽  
Marcus Oelze ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Raw Materials ◽  
Metal Sulfide ◽  
Tectonic Activity ◽  
Light Rare Earth ◽  
Bulk Rock ◽  
Polymetallic Mineralization ◽  
High Concentrations ◽  
Light Rare Earth Elements

AbstractSituated in the western Erzgebirge metallogenetic province (Vogtland, Germany), the Eichigt prospect is associated with several quartz-Mn-Fe-oxyhydroxide veins that are exposed at surface. Bulk-rock geochemical assays of vein material yield high concentrations of Li (0.6–4.1 kg/t), Co (0.6–14.7 kg/t), and Ni (0.2–2.8 kg/t), as well as significant quantities of Mn, Cu, and light rare earth elements, a very unusual metal tenor closely resembling the mixture of raw materials needed for Li-ion battery production. This study reports on the results of a first detailed investigation of this rather unique polymetallic mineralization style, including detailed petrographic and mineralogical studies complemented by bulk rock geochemistry, electron microprobe analyses, and laser ablation inductively coupled mass spectrometry. The mineralized material comprises an oxide assemblage of goethite hematite, hollandite, and lithiophorite that together cement angular fragments of vein quartz. Lithiophorite is the predominant host of Li (3.6–11.1 kg/t), Co (2.5–54.5 kg/t), and Ni (0.2–8.9 kg/t); Cu is contained in similar amounts in hollandite and lithiophorite whereas light rare earth elements (LREE) are mainly hosted in microcrystalline rhabdophane and florencite, which are finely intergrown with the Mn-Fe-oxyhydroxides. 40Ar/39Ar ages (~ 40–34 Ma) of coronadite group minerals coincide with tectonic activity related to the Cenozoic Eger Graben rifting. A low-temperature hydrothermal overprint of pre-existing base metal sulfide-quartz mineralization on fault structures that were reactivated during continental rifting is proposed as the most likely origin of the polymetallic oxyhydroxide mineralization at Eichigt. However, tectonically enhanced deep-reaching fracture-controlled supergene weathering cannot be completely ruled out as the origin of the mineralization.

The Role of Siderophores in the Transport of Radionuclides

1992 ◽  
Vol 294 ◽  
Author(s):  
Larry E. Hersman ◽  
Philip D. Palmer ◽  
David E. Hobart
Keyword(s):  
Ionic Radius ◽  
Chelating Agents ◽  
Ethylenediaminetetraacetic Acid ◽  
Binding Constants ◽  
Subsurface Environment ◽  
Naturally Occurring ◽  
Trisodium Salt ◽  
Aerobic Soil ◽  
Soil And Water

ABSTRACTIron exists in aerobic soil and water environments most commonly as insoluble Fe(III). Siderophores are powerful, microbially produced chelating agents that are used to mobilize the insoluble Fe(III) cation. Over 80 siderophores have been isolated and characterized, with some reportedly having iron-binding constants as high as 1052. Fe(III) and Pu(IV) are similar in their charge/ionic radius ratio (4.6 and 4.2, respectively); therefore, Pu(IV) may serve as analog to Fe(III). It is possible that some radioactive wastes could be chelated by naturally occurring siderophores, thereby altering the transport rates of those elements through the subsurface environment. This investigation wn 9 initiated to investigate that possibility. The binding of 239Pu(IV) by four chelating agents is reported in this paper: a siderophore isolated and purified from a Pseudomonas sp.; desferal, a ferrioxamine siderophore commonly used for deferration therapy; EDTA, ethylenediaminetetraacetic acid; and, citrate, trisodium salt.

The role of naturally occurring organic compounds in causing soil water repellency

2013 ◽  
Vol 64 (5) ◽  
pp. 667-680 ◽  
Author(s):  
K. Mainwaring ◽  
I. L. Hallin ◽  
P. Douglas ◽  
S. H. Doerr ◽  
C. P. Morley
Keyword(s):  
Soil Water ◽  
Organic Compounds ◽  
Water Repellency ◽  
Soil Water Repellency ◽  
Naturally Occurring

scholarly journals Dietary Phytochemicals in Zinc Homeostasis: A Strategy for Prostate Cancer Management

Nutrients ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1867
Author(s):  
Chandra K. Singh ◽  
Gagan Chhabra ◽  
Arth Patel ◽  
Hao Chang ◽  
Nihal Ahmad
Keyword(s):  
Prostate Cancer ◽  
Zinc Homeostasis ◽  
Cancer Management ◽  
Prostate Cells ◽  
Naturally Occurring ◽  
Dietary Phytochemicals ◽  
High Concentrations ◽  
Prostate Cancer Management ◽  
Malignant Prostate

Studies have suggested an important role of the trace element zinc (Zn) in prostate biology and functions. Zn has been shown to exist in very high concentrations in the healthy prostate and is important for several prostatic functions. In prostate cancer (PCa), Zn levels are significantly decreased and inversely correlated with disease progression. Ideally, restoration of adequate Zn levels in premalignant/malignant prostate cells could abort prostate malignancy. However, studies have shown that Zn supplementation is not an efficient way to significantly increase Zn concentrations in PCa. Based on a limited number of investigations, the reason for the lower levels of Zn in PCa is believed to be the dysregulation of Zn transporters (especially ZIP and ZnT family of proteins), metallothioneins (for storing and releasing Zn), and their regulators (e.g., Zn finger transcription factor RREB1). Interestingly, the level of Zn in cells has been shown to be modulated by naturally occurring dietary phytochemicals. In this review, we discussed the effect of selected phytochemicals (quercetin, resveratrol, epigallocatechin-3-gallate and curcumin) on Zn functioning and proposes that Zn in combination with specific dietary phytochemicals may lead to enhanced Zn bioaccumulation in the prostate, and therefore, may inhibit PCa.

scholarly journals Volatile Organic Compounds in the Azteca/Cecropia Ant-Plant Symbiosis and the Role of Black Fungi

2021 ◽  
Vol 7 (10) ◽  
pp. 836
Author(s):  
Veronika E. Mayer ◽  
Sybren de Hoog ◽  
Simona M. Cristescu ◽  
Luciano Vera ◽  
Francesc X. Prenafeta-Boldú
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Defense Mechanism ◽  
Hollow Structures ◽  
Tropical Plant ◽  
Volatile Organic ◽  
Black Fungi ◽  
High Concentrations ◽  
Background Air

Black fungi of the order Chaetothyriales are grown by many tropical plant-mutualistic ants as small so-called “patches” in their nests, which are located inside hollow structures provided by the host plant (“domatia”). These fungi are introduced and fostered by the ants, indicating that they are important for the colony. As several species of Chaetothyriales tolerate, adsorb, and metabolize toxic volatiles, we investigated the composition of volatile organic compounds (VOCs) of selected domatia in the Azteca/Cecropia ant-plant mutualism. Concentrations of VOCs in ant-inhabited domatia, empty domatia, and background air were compared. In total, 211 compounds belonging to 19 chemical families were identified. Ant-inhabited domatia were dominated by ketones with 2-heptanone, a well-known ant alarm semiochemical, as the most abundant volatile. Empty domatia were characterized by relatively high concentrations of the monoterpenes d-limonene, p-cymene and β-phellandrene, as well as the heterocyclic sulphur-containing compound, benzothiazole. These compounds have biocidal properties and are primarily biosynthesized by plants as a defense mechanism. Interestingly, most of the latter compounds were present at lower concentrations in ant inhabited domatia than in non-colonized ones. We suggest that Chaetothyriales may play a role in reducing the VOCs, underlining that the mutualistic nature of these fungi as VOCs accumulation might be detrimental for the ants, especially the larvae.

Phosphatian coffinite with rare earth elements and Ce-rich françoisite-(Nd) from sandstone beneath a natural fission reactor at Bangombé, Gabon

1996 ◽  
Vol 60 (401) ◽  
pp. 665-669 ◽  
Author(s):  
Janusz Janeczek ◽  
Rodney Ewing
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Spontaneous Fission ◽  
Uranium Deposit ◽  
Uranium Deposits ◽  
Light Rare Earth ◽  
Fission Reactor ◽  
Mineralogical Study ◽  
High Concentrations ◽  
Light Rare Earth Elements

Spontaneous fission reactions occurred in several uranium deposits in SE Gabon approximately two billion years ago. The reactor zones, between 10 to 50 cm thick, are found in Proterozoic sandstones and consist of high-grade uranium ore mantled by illite and/or chlorite (Gauthier-Lafaye et al., 1989). During a mineralogical study of sandstones (quartz arenites) underlying a natural fission reactor at Bangombé (20 km south of the Oklo uranium deposit), we have found several grains of a uranous silicate, coffinite, with unusually high concentrations of phosphorous and enriched in light rare earth elements (LREE).

scholarly journals Curcumin, Gut Microbiota, and Neuroprotection

Nutrients ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2426 ◽  
Author(s):  
Di Meo ◽  
Margarucci ◽  
Galderisi ◽  
Crispi ◽  
Peluso
Keyword(s):  
Neurological Diseases ◽  
Aqueous Solubility ◽  
Brain Health ◽  
Active Metabolites ◽  
Pharmacological Activities ◽  
Naturally Occurring ◽  
The Central Nervous System ◽  
High Concentrations

Curcumin, a nontoxic, naturally occurring polyphenol, has been recently proposed for the management of neurodegenerative and neurological diseases. However, a discrepancy exists between the well-documented pharmacological activities that curcumin seems to possess in vivo and its poor aqueous solubility, bioavailability, and pharmacokinetic profiles that should limit any therapeutic effect. Thus, it is possible that curcumin could exert direct regulative effects primarily in the gastrointestinal tract, where high concentrations of curcumin are present after oral administration. Indeed, a new working hypothesis that could explain the neuroprotective role of curcumin despite its limited availability is that curcumin acts indirectly on the central nervous system by influencing the “microbiota–gut–brain axis”, a complex bidirectional system in which the microbiome and its composition represent a factor which preserves and determines brain “health”. Interestingly, curcumin and its metabolites might provide benefit by restoring dysbiosis of gut microbiome. Conversely, curcumin is subject to bacterial enzymatic modifications, forming pharmacologically more active metabolites than curcumin. These mutual interactions allow to keep proper individual physiologic functions and play a key role in neuroprotection.

scholarly journals Specific Features of Fluid and Hydrothermal Inclusions in Minerals

2021 ◽  
Vol 20 (2) ◽  
pp. 110-124
Author(s):  
N.N. Zinchuk ◽  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Light Rare Earth ◽  
Temperature Analysis ◽  
The World ◽  
Microelement Composition ◽  
Material Transportation ◽  
Light Rare Earth Elements ◽  
Diamondiferous Kimberlite

Characteristics of new genetic type of inclusions being formed during boiling up of magma or hydrotherms is given. It is indicated that the form and sizes of inclusions of boiling up fluids have important role in studying the nature of minerals. Examples of analysis using the composition and temperature homogenous process of individual mineral groups’ inclusions from definite deposits of the world have been analyzed. Temperature analysis of individual inclusions homogenous process indicates that under certain conditions, separation of homogenous magmatic melt into two parts (silicate and sulphate) takes place. Comparison of microelement composition of kimberlites of various productivity indicated similarity of behavior spectra of light rare earth elements in commercially diamondiferous kimberlite bodies. Assessment of quantitative role of various mantle paragenesises in parent kimberlites with consideration of selective capture of depth material by proto-kimberlite melts, specific features of captured material transportation to the surface, and stability of diamonds in depth melts is of big interest. One should consider those parameters and processes, analysis of which may help in gaining better understanding of mechanisms of kimberlites’ productivity origination.

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