Acute inhibition of iron bioavailability by zinc: studies in humans.

Science.gov (United States)

Olivares, Manuel; Pizarro, Fernando; Ruz, Manuel; de Romaña, Daniel López

2012-08-01

Iron (Fe) and zinc (Zn) deficiencies constitute two of the most important nutritional and public health problems affecting developing countries. Combined supplementation or fortification with Zn and Fe are strategies that can be used to improve the Zn and Fe status of a population. However, there is concern about potential negative interactions between these two micronutrients due to a competitive binding to DMT1 and Zip14 transporter. Studies performed in humans have shown an inhibitory effect of Zn on Fe absorption when both minerals are given together as a solution in fasting conditions. We found that at low doses of iron (0.5 mg) the threshold for the inhibition of iron bioavailability was at a Zn:Fe wt/wt ratio ≥5.9:1, whereas at higher doses of Fe (10 mg) this inhibition occurred at 1:1 Zn:Fe wt/wt ratio. This differential response could be explained by the variation in the abundance of both cations as they compete for a limited number of shared transporters at the enterocyte. Conflicting results have been obtained when this interaction was studied in different food matrices. A negative interaction was not observed when Fe and Zn were provided in a composite hamburger meal, premature formula, human milk, or cow milk. A decrease on Fe absorption was observed in only 1 of 3 studies when Fe and Zn were supplied in wheat flour. The possibility of a negative interaction should be considered for supplementation or fortification programs with both microminerals.

Effect of excess supply of heavy metals on the absorption and translocation of iron (/sup 59/Fe) in barley

Energy Technology Data Exchange (ETDEWEB)

Sharma, C P; Bisht, S S; Agarwala, S C [Lucknow Univ. (India). Dept. of Botany

1978-03-01

The effects of an excess supply of manganese, copper, zinc, cobalt, and nickel on the absorption and translocation of iron tagged with /sup 59/Fe were xamined in 15 days old barley seedlings raised in solution culture. Excess heavy metal treatments and /sup 59/Fe were administered in three different ways: (i) both excess heavy metals and iron supplied through roots- Series A; (ii) excess heavy metal supplied as foliar spray and iron through roots- Series B; and (iii) excess heavy metal supplied through roots and iron as foliar spray-Series C. Results obtained revealed that excess concentrations of manganese, zinc, cobalt, and a to a lesser extent copper interfered with the absorption of iron from the rooting medium, but excess nickel enhanced the absorption and translocation of iron. Thus, unlike other metals, a toxic supply of nickel does not induce iron deficiency.

IRON, ZINC, AND FERRITIN ACCUMULATION IN COMMON BEANS

DEFF Research Database (Denmark)

Urbanski, Dorian Fabian; Sørensen, Kirsten; Jurkiewicz, Anna Malgorzata

Iron and zinc malnutrition are major threats to human health and development around the world. The World Health Organization states that over two billion people are affected by iron deficiency. In particular children and pregnant women in developing countries are affected by iron deficiency...... in mature seeds, but the ferritin protein was suggested to be the major iron storing protein in legumes [1]. Both iron and zinc localization, as well as speciation, can have an impact on their nutritional availability. We will present detailed information about iron, zinc, and ferritin distribution...

Genome Wide Identification of Orthologous ZIP Genes Associated with Zinc and Iron Translocation in Setaria italica

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Ganesh Alagarasan

2017-05-01

Full Text Available Genes in the ZIP family encode transcripts to store and transport bivalent metal micronutrient, particularly iron (Fe and or zinc (Zn. These transcripts are important for a variety of functions involved in the developmental and physiological processes in many plant species, including most, if not all, Poaceae plant species and the model species Arabidopsis. Here, we present the report of a genome wide investigation of orthologous ZIP genes in Setaria italica and the identification of 7 single copy genes. RT-PCR shows 4 of them could be used to increase the bio-availability of zinc and iron content in grains. Of 36 ZIP members, 25 genes have traces of signal peptide based sub-cellular localization, as compared to those of plant species studied previously, yet translocation of ions remains unclear. In silico analysis of gene structure and protein nature suggests that these two were preeminent in shaping the functional diversity of the ZIP gene family in S. italica. NAC, bZIP and bHLH are the predominant Fe and Zn responsive transcription factors present in SiZIP genes. Together, our results provide new insights into the signal peptide based/independent iron and zinc translocation in the plant system and allowed identification of ZIP genes that may be involved in the zinc and iron absorption from the soil, and thus transporting it to the cereal grain underlying high micronutrient accumulation.

Characterization of copper oxides, iron oxides, and zinc copper ferrite desulfurization sorbents by X-ray photoelectron spectroscopy and scanning electron microscopy

Science.gov (United States)

Siriwardane, Ranjani V.; Poston, James A.

1993-05-01

Characterization of copper oxides, iron oxides, and zinc copper ferrite desulfurization sorbents was performed by X-ray photoelectron spectroscopy and scanning electron microscopy/energy-dispersive spectroscopy at temperatures of 298 to 823 K. Analysis of copper oxides indicated that the satellite structure of the Cu22p region was absent in the Cu(I) state but was present in the Cu(II) state. Reduction of CuO at room temperature was observed when the ion gauge was placed close to the sample. The satellite structure was absent in all the copper oxides at 823 K in vacuum. Differentiation of the oxidation state of copper utilizing both Cu(L 3M 4,5M 4,5) X-ray-induced Auger lines and Cu2p satellite structure, indicated that the copper in zinc copper ferrite was in the + 1 oxidation state at 823 K. This + 1 state of copper was not significantly changed after exposure to H 2, CO, and H 2O. There was an increase in Cu/Zn ratio and a decrease in Fe/Zn ratio on the surface of zinc copper ferrite at 823 K compared to that at room temperature. These conditions of copper offered the best sulfidation equilibrium for the zinc copper ferrite desulfurization sorbent. Analysis of iron oxides indicated that there was some reduction of both Fe 2O 3 and FeO at 823K. The iron in zinc copper ferrite was similar to that of Fe 2O 3 at room temperature but there was some reduction of this Fe(III) state to Fe(II) at 823 K. This reduction was more enhanced in the presence of H 2 and CO. Reduction to Fe(II) may not be desirable for the lifetime of the sorbent.

Zinc bioleaching from an iron concentrate using Acidithiobacillus ferrooxidans strain from Hercules Mine of Coahuila, Mexico

Science.gov (United States)

Núñez-Ramírez, Diola Marina; Solís-Soto, Aquiles; López-Miranda, Javier; Pereyra-Alférez, Benito; Rutiaga-Quiñónes, Miriam; Medina-Torres, Luis; Medrano-Roldán, Hiram

2011-10-01

The iron concentrate from Hercules Mine of Coahuila, Mexico, which mainly contained pyrite and pyrrhotite, was treated by the bioleaching process using native strain Acidithiobacillus ferrooxidans ( A. ferrooxidans) to determine the ability of these bacteria on the leaching of zinc. The native bacteria were isolated from the iron concentrate of the mine. The bioleaching experiments were carried out in shake flasks to analyze the effects of pH values, pulp density, and the ferrous sulfate concentration on the bioleaching process. The results obtained by microbial kinetic analyses for the evaluation of some aspects of zinc leaching show that the native bacteria A. ferrooxidans, which is enriched with a 9K Silverman medium under the optimum conditions of pH 2.0, 20 g/L pulp density, and 40 g/L FeSO4, increases the zinc extraction considerably observed by monitoring during15 d, i.e., the zinc concentration has a decrease of about 95% in the iron concentrate.

A Low-Cost Neutral Zinc-Iron Flow Battery with High Energy Density for Stationary Energy Storage.

Science.gov (United States)

Xie, Congxin; Duan, Yinqi; Xu, Wenbin; Zhang, Huamin; Li, Xianfeng

2017-11-20

Flow batteries (FBs) are one of the most promising stationary energy-storage devices for storing renewable energy. However, commercial progress of FBs is limited by their high cost and low energy density. A neutral zinc-iron FB with very low cost and high energy density is presented. By using highly soluble FeCl 2 /ZnBr 2 species, a charge energy density of 56.30 Wh L -1 can be achieved. DFT calculations demonstrated that glycine can combine with iron to suppress hydrolysis and crossover of Fe 3+ /Fe 2+ . The results indicated that an energy efficiency of 86.66 % can be obtained at 40 mA cm -2 and the battery can run stably for more than 100 cycles. Furthermore, a low-cost porous membrane was employed to lower the capital cost to less than $ 50 per kWh, which was the lowest value that has ever been reported. Combining the features of low cost, high energy density and high energy efficiency, the neutral zinc-iron FB is a promising candidate for stationary energy-storage applications. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effect of Consuming Zinc-fortified Bread on Serum Zinc and Iron Status of Zinc-deficient Women: A Double Blind, Randomized Clinical Trial.

Science.gov (United States)

Badii, Akbar; Nekouei, Niloufar; Fazilati, Mohammad; Shahedi, Mohammad; Badiei, Sajad

2012-03-01

After iron deficiency, zinc deficiency is the major micronutrient deficiency in developing countries, and staple food fortification is an effective strategy to prevent and improve it among at-risk-populations. No action has been taken to reduce zinc deficiency via flour fortification so far in Iran, and little is known about the influence of zinc fortification of flour on serum zinc and the iron status, and also about the optimum and effective amount of zinc compound that is used in food fortification. The objective of this study is to evaluate the influence of consuming zinc-fortified breads on the zinc and iron status in the blood serum. In this study, three types of bread were prepared from non-fortified and fortified flours, with 50 and 100 ppm elemental zinc in the form of sulfate. Eighty zinc-deficient women aged 19 to 49 years were randomly assigned to three groups; The volunteers received, daily, (1) a non-fortified bread, (2) a high-zinc bread, and (3) a low-zinc bread for one month. Serum zinc and iron were measured by Atomic Absorption before and after the study. Results showed a significant increase in serum zinc and iron levels in all groups (p 0.05). Absorption of zinc and iron in the group that consumed high-zinc bread was significantly greater than that in the group that received low-zinc bread (p bread improved iron absorption.

Effect of consuming zinc-fortified bread on serum zinc and iron status of zinc-deficient women: A double blind, randomized clinical trial

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Akbar Badii

2012-01-01

Full Text Available After iron deficiency, zinc deficiency is the major micronutrient deficiency in developing countries, and staple food fortification is an effective strategy to prevent and improve it among at-risk-populations. No action has been taken to reduce zinc deficiency via flour fortification so far in Iran, and little is known about the influence of zinc fortification of flour on serum zinc and the iron status, and also about the optimum and effective amount of zinc compound that is used in food fortification. The objective of this study is to evaluate the influence of consuming zinc-fortified breads on the zinc and iron status in the blood serum. In this study, three types of bread were prepared from non-fortified and fortified flours, with 50 and 100 ppm elemental zinc in the form of sulfate. Eighty zinc-deficient women aged 19 to 49 years were randomly assigned to three groups; The volunteers received, daily, (1 a non-fortified bread, (2 a high-zinc bread, and (3 a low-zinc bread for one month. Serum zinc and iron were measured by Atomic Absorption before and after the study. Results showed a significant increase in serum zinc and iron levels in all groups (p 0.05. Absorption of zinc and iron in the group that consumed high-zinc bread was significantly greater than that in the group that received low-zinc bread (p < 0.01. It was concluded that fortification of flour with 50-100 ppm zinc was an effective way to achieve adequate zinc intake and absorption in zinc-deficient people. It also appeared that consuming zinc-fortified bread improved iron absorption.

Effects of iron, tin, and copper on zinc absorption in humans

International Nuclear Information System (INIS)

Valberg, L.S.; Flanagan, P.R.; Chamberlain, M.J.

1984-01-01

Zinc absorption as measured by body retention of [65Zn]zinc chloride or a turkey test meal extrinsically labeled with 65Zn was determined in human subjects by whole body counting after 7 days. Average 65Zn absorption from zinc chloride in persons with a high iron-absorbing capacity was similar to persons with a low capacity to absorb iron. Inorganic iron, 920 mumol (51 mg), or HB iron, 480 mumol (26 mg), inhibited 65Zn absorption from 92 mumol (6 mg) of zinc chloride. When 610 mumol of iron (34 mg) was added to a turkey test meal containing 61 mumol of zinc (4 mg), 65Zn absorption was not inhibited. Tin, 306 mumol (36 mg), given with zinc chloride or turkey test meals (61 mumol, 4 mg, of Zn) significantly reduced 65Zn absorption. Copper, 79 mumol (5 mg), had no significant effect on the 65Zn absorption from 7.9 mumol (0.5 mg) of zinc chloride. In summary, the capacity to absorb iron did not influence 65Zn absorption, but both inorganic iron and heme-iron inhibited 65Zn absorption from zinc chloride. Inorganic iron had no effect, however, on 65Zn absorption from the turkey test meal. Tin in a large dose also inhibited 65Zn absorption from both zinc chloride and the turkey test meal

Extraction chromatographic separation of iron from complex liquid samples and the determination of 55Fe

International Nuclear Information System (INIS)

Grahek, Z.; Rozmaric Macefat, M.

2006-01-01

Iron separation is described from liquid samples with a high concentration of ions that enables simple determination of 55 Fe. One of the described methods consists of iron precipitation from a large volume seawater by sodium hydroxide and/or ammonium carbonate and separation from other elements (Ca, Sr, Cu, Mg, etc.) on a TRU column with 4M HCl or 8M HNO 3 . In the other procedure iron is separated directly from a mixture of seawater samples and HCl on a TRU column. In both methods, the iron recovery is almost 100%. After separation, 55 Fe is determined by counting with a liquid scintillation counter. The binding of Fe and Zn on TEVA, U/TEVA and TRU resins from seawater solutions of HCl and HNO 3 depends on the type of the resin, concentration of acid and other ions. Iron and zinc can be separated from seawater on a U/TEVA column with 2M HCl. (author)

The solvent extraction of zinc, iron, and indium from chloride solutions by neutral organophosphorus compounds

International Nuclear Information System (INIS)

Preston, J.S.; Du Preez, A.C.

1985-01-01

The preparation of several neutral organophosphorus compounds and their evaluation as selective extractants for zinc in chloride media are described. The compounds belong to the series trialkyl phosphates (RO) 3 PO, dialkyl alkylphosphonates R'PO(OR) 2 , alkyl dialkylphosphinates R 2 'PO(OR), and trialkyl-phosphine oxides R 3 'PO. They were characterized by measurement of their physical properties (melting and boiling points, refractive indices, and densities), and their purities were confirmed by osmometric determination of their molecular masses; by carbon and hydrogen microanalysis; by the titrimetric determination of acidic impurities; and, for liquid products, by comparison of their experimental molar refractivities with empirical values. Metal-distribution equilibria were determined for solutions of the extractants in xylene and aqueous phase containing 0,5 to 5,0 M sodium chloride. Moderately good selectivities were shown for zinc(II) over iron(III), and excellent selectivities were shown for zinc(II) over iron(II), copper(II), lead(II), and cadmium(II). The extraction of indium(III) was similar to that of zinc(II). The extraction of zinc(III), iron(III), and indium(III) increased markedly through the series. (RO) 3 PO 2 2 'PO(OR) 3 'PO. The incorporation of phenyl groups into the compounds led to weaker extraction. The extracted complexes of zinc(II), iron(III), and indium(III) have the stoichiometries ZnCl 2 L 2 ,FeCl 3 L 2 (H 2 O), and InCl 3 L 2 (H 2 O) respectively, where L represents the neutral organophosphorus compound

Iron and zinc availability in maize lines

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Valéria Aparecida Vieira Queiroz

2011-09-01

Full Text Available The aim of this study was to characterize the Zn and Fe availability by phytic acid/Zn and phytic acid/Fe molar ratios, in 22 tropical maize inbred lines with different genetic backgrounds. The Zn and Fe levels were determined by atomic absorption spectrophotometry and the P through colorimetry method. Three screening methods for phytic acid (Phy analysis were tested and one, based on the 2,2'-bipyridine reaction, was select. There was significant variability in the contents of zinc (17.5 to 42 mg.kg-1, iron (12.2 to 36.7 mg.kg-1, phosphorus (230 to 400 mg.100 g-1, phytic acid (484 to 1056 mg.100 g-1, phytic acid P (140 to 293 mg.100 g-1 and available-P (43.5 to 199.5 mg.100 g-1, and in the available-P/total-P ratio (0.14 to 0.50, Phy/Zn (18.0 to 43.5 and Phy/Fe (16.3 to 45.5 molar ratios. Lines 560977, 560978 and 560982 had greater availability of Zn and lines 560975, 560977, 561010 and 5610111 showed better Fe availability. Lines 560975, 560977 and 560978 also showed better available-P/total-P ratio. Thus, the lines 560975, 560977 and 560978 were considered to have the potential for the development of cultivars of maize with high availability of Fe and/or Zn.

Microwave Synthesis of Fe2 O3 and ZnO Nanoparticles and Evaluation Its Application on Grain Iron and Zinc Concentrations of Wheat (Triticum aestivum L. and their Relationships to Grain Yield

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Shahab Khaghani

2016-04-01

Full Text Available Fe2O3 and ZnO nanoparticles were synthesized by a fast microwave method. Nanostructures were characterized by X-ray diffraction  and scanning electron microscopy. The goal of bio-fortification is to develop plants that have an increased content of bioavailable nutrients in their edible parts. The micronutrients magnesium (Mg, manganese (Mn and copper (Cu, boron (B and calcium (Ca are essential for plants and the humans and animals that consume plants. Increasing the micronutrient density of staple crops, will greatly improve human nutrition on a global scale. In order to investigate the effect of Iron and Zinc on nutrient uptake of two line of wheat. The experimental design used for this research was a factorial experiment under complete randomized block design with three replications and two variety of wheat including Roshan back cross (V1 and C-78-14 line (V2, three levels of Iron from Fe-EDDHA (Sequestrene138 including no application (F0, Fe sulphate (F1 and Nano Fe2O3 (F2 and three Levels of  Zinc as zinc sulphate (ZnSO4 including no application (Z0, 25 kg/ha-1 (Z1 and 50 kg/ha-1 (Z2 were used. The result is showed that application of nanoparticles increased the study of parameters such as magnesium, manganese, copper, boron and calcium. Highest levels of grain yield with 5.13 ton/ha-1 was obtained in C-78-14 variety.

The iron uptake repressor Fep1 in the fission yeast binds Fe-S cluster through conserved cysteines

Energy Technology Data Exchange (ETDEWEB)

Kim, Hyo-Jin; Lee, Kang-Lok; Kim, Kyoung-Dong; Roe, Jung-Hye, E-mail: jhroe@snu.ac.kr

2016-09-09

Iron homeostasis is tightly regulated since iron is an essential but toxic element in the cell. The GATA-type transcription factor Fep1 and its orthologs contribute to iron homeostasis in many fungi by repressing genes for iron uptake when intracellular iron is high. Even though the function and interaction partners of Fep1 have been elucidated extensively In Schizosaccharomyces pombe, the mechanism behind iron-sensing by Fep1 remains elusive. It has been reported that Fep1 interacts with Fe-S-containing monothiol glutaredoxin Grx4 and Grx4-Fra2 complex. In this study, we demonstrate that Fep1 also binds iron, in the form of Fe-S cluster. Spectroscopic and biochemical analyses of as isolated and reconstituted Fep1 suggest that the dimeric Fep1 binds Fe-S clusters. The mutation study revealed that the cluster-binding depended on the conserved cysteines located between the two zinc fingers in the DNA binding domain. EPR analyses revealed [Fe-S]-specific peaks indicative of mixed presence of [2Fe-2S], [3Fe-4S], or [4Fe-4S]. The finding that Fep1 is an Fe-S protein fits nicely with the model that the Fe-S-trafficking Grx4 senses intracellular iron environment and modulates the activity of Fep1. - Highlights: • Fep1, a prototype fungal iron uptake regulator, was isolated stably from Schizosaccharomyces pombe. • Fep1 exhibits UV–visible absorption spectrum, characteristic of [Fe-S] proteins. • The iron and sulfide contents in purified or reconstituted Fep1 also support [Fe-S]. • The conserved cysteines are critical for [Fe-S]-binding. • EPR spectra at 5 K and 123 K suggest a mixed population of [Fe-S].

Influence of iron and zinc status on cadmium accumulation in Bangladeshi women

International Nuclear Information System (INIS)

Kippler, Maria; Ekstroem, Eva-Charlotte; Loennerdal, Bo; Goessler, Walter; Akesson, Agneta; El Arifeen, Shams; Persson, Lars-Ake; Vahter, Marie

2007-01-01

Cadmium is a widespread environmental contaminant present in food. The absorption in the intestine increases in individuals with low iron stores, but the effect of zinc deficiency is not clear. The aim of the present study was to assess the influence of iron and zinc status on cadmium accumulation in pregnant Bangladeshi women. We measured cadmium in urine from 890 women using inductively coupled plasma mass spectrometry (ICPMS). Further, we also measured ferritin and zinc in plasma. The median cadmium concentration in urine was 0.59 μg/L (adjusted to mean specific gravity of 1.012 g/mL). Analysis of covariance (ANCOVA) showed that urinary cadmium was associated with plasma ferritin and plasma zinc via a significant interaction between dichotomized plasma ferritin and plasma zinc. The analysis was adjusted for age and socioeconomic status. Women with low iron stores and adequate zinc status had significantly higher urinary cadmium compared to women with both adequate iron stores and zinc status. There was no difference in urinary cadmium between women with both low iron stores and zinc status compared to those with both adequate iron stores and zinc status. In conclusion, low iron stores were associated with increased cadmium accumulation, but only at adequate zinc status

Development and optimization of iron- and zinc-containing nanostructured powders for nutritional applications

Energy Technology Data Exchange (ETDEWEB)

Hilty, F M; Hurrell, R F; Zimmermann, M B [Human Nutrition Laboratory, Institute of Food Science and Nutrition, ETH Zurich (Switzerland); Teleki, A; Buechel, R; Pratsinis, S E [Particle Technology Laboratory, Department of Mechanical and Process Engineering, ETH Zurich (Switzerland); Krumeich, F, E-mail: michael.zimmermann@ilw.agrl.ethz.c [Electron Microscopy Center (EMEZ), ETH Zurich (Switzerland)

2009-11-25

Reducing the size of low-solubility iron (Fe)-containing compounds to nanoscale has the potential to improve their bioavailability. Because Fe and zinc (Zn) deficiencies often coexist in populations, combined Fe/Zn-containing nanostructured compounds may be useful for nutritional applications. Such compounds are developed here and their solubility in dilute acid, a reliable indicator of iron bioavailability in humans, and sensory qualities in sensitive food matrices are investigated. Phosphates and oxides of Fe and atomically mixed Fe/Zn-containing (primarily ZnFe{sub 2}O{sub 4}) nanostructured powders were produced by flame spray pyrolysis (FSP). Chemical composition and surface area were systematically controlled by varying precursor concentration and feed rate during powder synthesis to increase solubility to the level of ferrous sulfate at maximum Fe and Zn content. Solubility of the nanostructured compounds was dependent on their particle size and crystallinity. The new nanostructured powders produced minimal color changes when added to dairy products containing chocolate or fruit compared to the changes produced when ferrous sulfate or ferrous fumarate were added to these foods. Flame-made Fe- and Fe/Zn-containing nanostructured powders have solubilities comparable to ferrous and Zn sulfate but may produce fewer color changes when added to difficult-to-fortify foods. Thus, these powders are promising for food fortification and other nutritional applications.

Development and optimization of iron- and zinc-containing nanostructured powders for nutritional applications

International Nuclear Information System (INIS)

Hilty, F M; Hurrell, R F; Zimmermann, M B; Teleki, A; Buechel, R; Pratsinis, S E; Krumeich, F

2009-01-01

Reducing the size of low-solubility iron (Fe)-containing compounds to nanoscale has the potential to improve their bioavailability. Because Fe and zinc (Zn) deficiencies often coexist in populations, combined Fe/Zn-containing nanostructured compounds may be useful for nutritional applications. Such compounds are developed here and their solubility in dilute acid, a reliable indicator of iron bioavailability in humans, and sensory qualities in sensitive food matrices are investigated. Phosphates and oxides of Fe and atomically mixed Fe/Zn-containing (primarily ZnFe 2 O 4 ) nanostructured powders were produced by flame spray pyrolysis (FSP). Chemical composition and surface area were systematically controlled by varying precursor concentration and feed rate during powder synthesis to increase solubility to the level of ferrous sulfate at maximum Fe and Zn content. Solubility of the nanostructured compounds was dependent on their particle size and crystallinity. The new nanostructured powders produced minimal color changes when added to dairy products containing chocolate or fruit compared to the changes produced when ferrous sulfate or ferrous fumarate were added to these foods. Flame-made Fe- and Fe/Zn-containing nanostructured powders have solubilities comparable to ferrous and Zn sulfate but may produce fewer color changes when added to difficult-to-fortify foods. Thus, these powders are promising for food fortification and other nutritional applications.

Development and optimization of iron- and zinc-containing nanostructured powders for nutritional applications.

Science.gov (United States)

Hilty, F M; Teleki, A; Krumeich, F; Büchel, R; Hurrell, R F; Pratsinis, S E; Zimmermann, M B

2009-11-25

Reducing the size of low-solubility iron (Fe)-containing compounds to nanoscale has the potential to improve their bioavailability. Because Fe and zinc (Zn) deficiencies often coexist in populations, combined Fe/Zn-containing nanostructured compounds may be useful for nutritional applications. Such compounds are developed here and their solubility in dilute acid, a reliable indicator of iron bioavailability in humans, and sensory qualities in sensitive food matrices are investigated. Phosphates and oxides of Fe and atomically mixed Fe/Zn-containing (primarily ZnFe2O4) nanostructured powders were produced by flame spray pyrolysis (FSP). Chemical composition and surface area were systematically controlled by varying precursor concentration and feed rate during powder synthesis to increase solubility to the level of ferrous sulfate at maximum Fe and Zn content. Solubility of the nanostructured compounds was dependent on their particle size and crystallinity. The new nanostructured powders produced minimal color changes when added to dairy products containing chocolate or fruit compared to the changes produced when ferrous sulfate or ferrous fumarate were added to these foods. Flame-made Fe- and Fe/Zn-containing nanostructured powders have solubilities comparable to ferrous and Zn sulfate but may produce fewer color changes when added to difficult-to-fortify foods. Thus, these powders are promising for food fortification and other nutritional applications.

Iron and Zinc Nutrition in the Economically-Developed World: A Review

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Alison O. Booth

2013-08-01

Full Text Available This review compares iron and zinc food sources, dietary intakes, dietary recommendations, nutritional status, bioavailability and interactions, with a focus on adults in economically-developed countries. The main sources of iron and zinc are cereals and meat, with fortificant iron and zinc potentially making an important contribution. Current fortification practices are concerning as there is little regulation or monitoring of intakes. In the countries included in this review, the proportion of individuals with iron intakes below recommendations was similar to the proportion of individuals with suboptimal iron status. Due to a lack of population zinc status information, similar comparisons cannot be made for zinc intakes and status. Significant data indicate that inhibitors of iron absorption include phytate, polyphenols, soy protein and calcium, and enhancers include animal tissue and ascorbic acid. It appears that of these, only phytate and soy protein also inhibit zinc absorption. Most data are derived from single-meal studies, which tend to amplify impacts on iron absorption in contrast to studies that utilize a realistic food matrix. These interactions need to be substantiated by studies that account for whole diets, however in the interim, it may be prudent for those at risk of iron deficiency to maximize absorption by reducing consumption of inhibitors and including enhancers at mealtimes.

Teneurs en oligo-éléments cuivre (Cu, fer (Fe, manganèse (Mn et zinc (Zn, et rapport fer-manganèse (Fe : Mn des pâturages naturels de la Sous-Région de l'Ituri (République du Zaïre

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Sikumbili, V.

1986-01-01

Full Text Available Copper (Cu. Iron (Fe, Manganese (Mn and Zinc (Zn and Iran to Manganese ratio (Fe/Mn in natural pastures of Ituri region (Republic of Zaire. The concentrations of Copper, Iron, Manganese and Zinc, and the Iron to Manganese ratios were determined in 91 samples of pasture grasses from different parts of Ituri area, in Zaire. The samples were divided into 3 groups or sectors according to their geographic origin (southern, middle and northern, and refer to 20 different species of graminaceae. Analytical results showed normal levels of Copper. Iron and Manganese (Overall mean values of 12.33 ppm DM, 103.75 ppm DM and 81.75 ppm DM respectively. The levels of Zinc were generally very low and the mean value in the whole material was 36.40 ppm DM. The general mean value of the Iron to Manganese ratio of 1.68 was satisfactory in spite of slightly low values in the middle (1.36 and the north (1.25.

Cytotoxicity, Intestinal Transport, and Bioavailability of Dispersible Iron and Zinc Supplements

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Jae-Min Oh

2017-04-01

Full Text Available Iron or zinc deficiency is one of the most important nutritional disorders which causes health problem. However, food fortification with minerals often induces unacceptable organoleptic changes during preparation process and storage, has low bioavailability and solubility, and is expensive. Nanotechnology surface modification to obtain novel characteristics can be a useful tool to overcome these problems. In this study, the efficacy and potential toxicity of dispersible Fe or Zn supplement coated in dextrin and glycerides (SunActive FeTM and SunActive ZnTM were evaluated in terms of cytotoxicity, intestinal transport, and bioavailability, as compared with each counterpart without coating, ferric pyrophosphate (FePP and zinc oxide (ZnO nanoparticles (NPs, respectively. The results demonstrate that the cytotoxicity of FePP was not significantly affected by surface modification (SunActive FeTM, while SunActive ZnTM was more cytotoxic than ZnO-NPs. Cellular uptake and intestinal transport efficiency of SunActive FeTM were significantly higher than those of its counterpart material, which was in good agreement with enhanced oral absorption efficacy after a single-dose oral administration to rats. These results seem to be related to dissolution, particle dispersibility, and coating stability of materials depending on suspending media. Both SunActiveTM products and their counterpart materials were determined to be primarily transported by microfold (M cells through the intestinal epithelium. It was, therefore, concluded that surface modification of food fortification will be a useful strategy to enhance oral absorption efficiency at safe levels.

Effect Of Joint Iron And Zinc Supplementation On Malarial Infection ...

African Journals Online (AJOL)

Adjusted geometric mean serum ferritin concentration in the Iron-zinc Group was significantly higher than in the Control Group (22.9 fg/L versus 16.9 fg/L), F (1, 156) = 6.336, p = 0.013. Conclusions: Joint iron and zinc supplementation appears to be a better option than iron-only supplementation in malaria-endemic areas.

Study of Doppler broadened annihilation spectra in zinc and zinc-containing 0.05 at. % iron

International Nuclear Information System (INIS)

Troev, T.; Zolov, R.; Dimova, V.; Levay, B.

1979-01-01

The Doppler broadening of annihilation gamma spectra obtained from positron-electron annihilation in pure polycrystalline zinc and zinc-containing 0.05 at. % iron have been investigated. The line shapes were measured by a Ge(Li) detector in coincidence with a NaI(Tl) scintillation detector. The results are quite consistent with those expected from the trapping model. The positrons are trapped by impurity atoms and vacancy-impurity pairs in zinc containing 0.05 at. % iron. (author)

Zinc transporter ZIP14 functions in hepatic zinc, iron and glucose homeostasis during the innate immune response (endotoxemia.

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Tolunay Beker Aydemir

Full Text Available ZIP14 (slc39A14 is a zinc transporter induced in response to pro-inflammatory stimuli. ZIP14 induction accompanies the reduction in serum zinc (hypozincemia of acute inflammation. ZIP14 can transport Zn(2+ and non-transferrin-bound Fe(2+ in vitro. Using a Zip14(-/- mouse model we demonstrated that ZIP14 was essential for control of phosphatase PTP1B activity and phosphorylation of c-Met during liver regeneration. In the current studies, a global screening of ZIP transporter gene expression in response to LPS-induced endotoxemia was conducted. Following LPS, Zip14 was the most highly up-regulated Zip transcript in liver, but also in white adipose tissue and muscle. Using ZIP14(-/- mice we show that ZIP14 contributes to zinc absorption from the gastrointestinal tract directly or indirectly as zinc absorption was decreased in the KOs. In contrast, Zip14(-/- mice absorbed more iron. The Zip14 KO mice did not exhibit hypozincemia following LPS, but do have hypoferremia. Livers of Zip14-/- mice had increased transcript abundance for hepcidin, divalent metal transporter-1, ferritin and transferrin receptor-1 and greater accumulation of iron. The Zip14(-/- phenotype included greater body fat, hypoglycemia and higher insulin levels, as well as increased liver glucose and greater phosphorylation of the insulin receptor and increased GLUT2, SREBP-1c and FASN expression. The Zip14 KO mice exhibited decreased circulating IL-6 with increased hepatic SOCS-3 following LPS, suggesting SOCS-3 inhibited insulin signaling which produced the hypoglycemia in this genotype. The results are consistent with ZIP14 ablation yielding abnormal labile zinc pools which lead to increased SOCS-3 production through G-coupled receptor activation and increased cAMP production as well as signaled by increased pSTAT3 via the IL-6 receptor, which inhibits IRS 1/2 phosphorylation. Our data show the role of ZIP14 in the hepatocyte is multi-functional since zinc and iron trafficking are

Serum Zinc, Iron and Copper Concentrations in Dogs Infected with Hepatozoon canis

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Kamil Seyrek

2009-01-01

Full Text Available In Turkey, canine hepatozoonosis is an emerging infection with a large number of cases detected during the past five years. In the present study, serum zinc, copper and iron concentrations of dogs infected with Hepatozoon canis were measured for the first time. Compared to the controls (n = 10, serum zinc and iron concentrations in infected animals (n = 14 decreased significantly (p p p Hepatozoon canis infection may cause alterations in serum zinc iron and copper concentrations. Furthermore, in the treatment of infected animals addition of zinc and iron to the ration of infected animals should be taken into consideration.

Counter diffusion of zinc and iron in alluvial soil

International Nuclear Information System (INIS)

Rattan, R.K.; Deb, D.L.

1980-01-01

Half cell technique showed that an increase in moisture tension and CaCO 3 content caused reduction in the counter diffusion coefficients of zinc and iron in an alluvial soil. Increases in bulk density, ambient temperature and concentration of synthetic chelating agents e.g. EDTA and DTPA increased the counter diffusion coefficients of both zinc and iron. (author)

Alkaline Leaching of Low Zinc Content Iron-Bearing Sludges

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Gargul K.

2016-03-01

Full Text Available Various types of waste materials containing zinc (e.g. dusts and sludges from gas dedusting process are obtained in steel industry. The contents of Zn in these materials may vary considerably. Even a low concentration of zinc in recirculated products precludes their recycling in ferrous metallurgy aggregates. Long storage of this type of material can lead to contamination of soil and water by zinc compounds which can be leached out by acid rain, for example. This paper focuses on research involving alkaline leaching tests of low zinc content iron-bearing materials. These tests were preceded by the analysis of the elemental, phase and grain size composition, and analysis of the thermodynamic conditions of the leaching process. The main aim of research was to decrease the content of the zinc in the sludge to the level where it is suitable as an iron-bearing material for iron production (~1% Zn. Leaching at elevated temperatures (368 K, 60 min has led to a decrease in the zinc content in the sludge of about 66%. The research revealed that long hour leaching (298 K, 100 hours carried out at ambient temperatures caused a reduction in zinc content by 60% to the value of 1.15-1.2% Zn.

Zinc and iron status during pregnancy of Filipino women.

Science.gov (United States)

de Jong, Nynke; Romano, Aurora B Ampong; Gibson, Rosalind S

2002-01-01

Low birthweight is associated with maternal anaemia and, in some circumstances, with low iron and zinc status, but this relationship has not been investigated in the Philippines. In this study, we assessed the prevalence of anaemia and suboptimal iron and zinc status in pregnant women from three geographical regions (mountain, coast, city) of Zamboanga del Sur province at 24 weeks (n = 305). and again at 36 weeks (n = 127), gestation. At 24 weeks, 34% were anaemic (i.e., haemoglobin values (i.e., 11 x 10(9)/L; 19%) and serum C-reactive protein (> 15 mg/L; 3%). Of the women surveyed, 20% were iron depleted but not anaemic, and 15% were zinc deficient (i.e., serum zinc values at 24 weeks gestation had infants with lower birthweights than those with values > or = 105 g/L and > or = 7.1 micromol/L, respectively. However, in the multivariate model, the contribution of maternal haemoglobin to the variance in birthweight at 24 weeks gestation was non-significant, although modest for serum zinc. Anaemia and/or suboptimal zinc status during pregnancy may be related to low birthweight in the Philippines, and their aetiology deserves further study.

Adsorption of poly(vinyl formamide-co-vinyl amine) (PVFA-co-PVAm) polymers on zinc, zinc oxide, iron, and iron oxide surfaces.

Science.gov (United States)

Seifert, Susan; Simon, Frank; Baumann, Giesela; Hietschold, Michael; Seifert, Andreas; Spange, Stefan

2011-12-06

The adsorption of poly(vinyl formamide) (PVFA) and the statistic copolymers poly(vinyl formamide-co-vinyl amine) (PVFA-co-PVAm) onto zinc and iron metal particles as well as their oxides was investigated. The adsorbates were characterized by means of XPS, DRIFT spectroscopy, wet chemical analysis, and solvatochromic probes. Dicyano-bis-(1,10-phenanthroline)-iron(II) (1), 3-(4-amino-3-methylphenyl)-7-phenyl-benzo-[1,2-b:4,5-b']difuran-2,6-dione (2), and 4-tert-butyl-2-(dicyano-methylene)-5-[4-(diethylamino)-benzylidene]-Δ(3)-thiazoline (3) as solvatochromic probes were coadsorbed onto zinc oxide to measure various effects of surface polarity. The experimental findings showed that the adsorption mechanism of PVFA and PVFA-co-PVAm strongly depends on the degree of hydrolysis of PVFA and pH values and also on the kind of metal or metal oxide surfaces that were employed as adsorbents. The adsorption mechanism of PVFA/PVFA-co-PVAm onto zinc oxide and iron oxide surfaces is mainly affected by electrostatic interactions. Particularly in the region of pH 5, the adsorption of PVFA/PVFA-co-PVAm onto zinc and iron metal particles is additionally influenced by redox processes, dissolution, and complexation reactions. © 2011 American Chemical Society

Solubility Measurements and Modeling of Zinc, Lead and Iron Sulfides at High Temperatures and High Pressures

DEFF Research Database (Denmark)

Carolina Figueroa Murcia, Diana; Fosbøl, Philip Loldrup; Thomsen, Kaj

Solubility measurements of sulfides in aqueous solutions are necessary to understand the behaviour of these scaling minerals in geothermal and oil reservoirs. The low solubility levels of Zinc Sulfide (ZnS), Lead Sulfide (PbS) and Iron Sulfide (FeS) make the solubility measurements a challenging...... oxygen atmosphere to avoid the risk of oxidation of sulfide minerals. The solution is kept in an equilibrium cell at constant temperature and pressure with continuous stirring. The concentration of Zn2+, Pb2+, Fe2+ and S2- are measured using Inductively Coupled Plasma Optical Emission spectrometry (ICP...

Impact of sorghum processing on phytate, phenolic compounds and in vitro solubility of iron and zinc in thick porridges

NARCIS (Netherlands)

Kayodé, A.P.P.; Linnemann, A.R.; Nout, M.J.R.; Boekel, van M.A.J.S.

2007-01-01

This study focussed on the impact of process variables on levels of phytate and phenolic compounds, and in vitro solubility of iron (Fe) and zinc (Zn) in sorghum porridges, a major staple in semi-arid tropics. The aim was to identify practices that enhance the mineral availability in this type of

Evaluation of Application Methods Efficiency of Zinc and Iron for Canola(Brassica napus L.

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Ahmad BYBORDI

2010-03-01

Full Text Available In order to evaluation of application method efficiency of zinc and iron microelements in canola, an experiment was conducted in the Agricultural Research Station of Eastern Azerbaijan province in 2008. The experimental design was a RCBD with eight treatments (F1: control, F2: iron, F3: zinc, F4: iron + zinc in the form of soil utility, F5: iron, F6: zinc, F7: iron+ zinc in the form of solution foliar application, and F8: iron + zinc in the form of soil utility and foliar application. Analysis of variance showed that there were significant differences among treatments on given traits, antioxidant enzymes activity, fatty acids percentage, plant height, seed weight to capitulum weight ratio, protein percentage, oil percentage, oil yield, 1000 seed weight, seed yield, nitrogen, phosphorous and potassium percentage of leaves, zinc and iron content of leaves and capitulum diameters. The highest seed yield, oil yield, oil percentage, 1000 seed weight, seed weight to capitulum weight ratio and protein percentage were obtained from the soil and foliar application of iron + zinc treatments (F8. Also, the highest amounts of nitrogen, phosphorous and potassium concentration in leaves were achieved from control treatment which was an indication of non-efficiency of iron and zinc on the absorption rate of these substances in the leaves. The correlation between effective traits on the seed yield, such as, capitalism diameter, number of seed rows in capitulum, seed weight to capitulum weight ratio and 1000 seed weight were positively significant. In general, foliar and soil application of zinc and iron had the highest efficiency in aspect of seed production. The comparison of the various methods of fertilization showed that foliar application was more effective than soil application. Also, micronutrient foliar application increased concentration of elements, especially zinc and iron. Antioxidant enzymes activity was different in response to treatments also the

Tissue levels of iron, copper, zinc and magnesium in iron deficient rats

African Journals Online (AJOL)

The effects of iron deficiency on the levels of iron, copper, zinc and magnesium in the brain, liver, kidney, heart and lungs of albino rats (Rattus novergicus) was investigated. Forty rats were divided into two groups and the first group was fed a control diet containing 1.09g iron/kg diet while the test group was fed diet ...

New perspectives on the regulation of iron absorption via cellular zinc concentrations in humans.

Science.gov (United States)

Knez, Marija; Graham, Robin D; Welch, Ross M; Stangoulis, James C R

2017-07-03

Iron deficiency is the most prevalent nutritional deficiency, affecting more than 30% of the total world's population. It is a major public health problem in many countries around the world. Over the years various methods have been used with an effort to try and control iron-deficiency anemia. However, there has only been a marginal reduction in the global prevalence of anemia. Why is this so? Iron and zinc are essential trace elements for humans. These metals influence the transport and absorption of one another across the enterocytes and hepatocytes, due to similar ionic properties. This paper describes the structure and roles of major iron and zinc transport proteins, clarifies iron-zinc interactions at these sites, and provides a model for the mechanism of these interactions both at the local and systemic level. This review provides evidence that much of the massive extent of iron deficiency anemia in the world may be due to an underlying deficiency of zinc. It explains the reasons for predominance of cellular zinc status in determination of iron/zinc interactions and for the first time thoroughly explains mechanisms by which zinc brings about these changes.

Genetic Variability, Genotype × Environment Interaction, Correlation, and GGE Biplot Analysis for Grain Iron and Zinc Concentration and Other Agronomic Traits in RIL Population of Sorghum (Sorghum bicolor L. Moench

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Rahul M. Phuke

2017-05-01

Full Text Available The low grain iron and zinc densities are well documented problems in food crops, affecting crop nutritional quality especially in cereals. Sorghum is a major source of energy and micronutrients for majority of population in Africa and central India. Understanding genetic variation, genotype × environment interaction and association between these traits is critical for development of improved cultivars with high iron and zinc. A total of 336 sorghum RILs (Recombinant Inbred Lines were evaluated for grain iron and zinc concentration along with other agronomic traits for 2 years at three locations. The results showed that large variability exists in RIL population for both micronutrients (Iron = 10.8 to 76.4 mg kg−1 and Zinc = 10.2 to 58.7 mg kg−1, across environments and agronomic traits. Genotype × environment interaction for both micronutrients (iron and zinc was highly significant. GGE biplots comparison for grain iron and zinc showed greater variation across environments. The results also showed that G × E was substantial for grain iron and zinc, hence wider testing needed for taking care of G × E interaction to breed micronutrient rich sorghum lines. Iron and zinc concentration showed high significant positive correlation (across environment = 0.79; p < 0.01 indicating possibility of simultaneous effective selection for both the traits. The RIL population showed good variability and high heritabilities (>0.60, in individual environments for Fe and Zn and other traits studied indicating its suitability to map QTL for iron and zinc.

Direct Iron Coating onto Nd-Fe-B Powder by Thermal Decomposition of Iron Pentacarbonyl

International Nuclear Information System (INIS)

Yamamuro, S; Okano, M; Tanaka, T; Sumiyama, K; Nozawa, N; Nishiuchi, T; Hirosawa, S; Ohkubo, T

2011-01-01

Iron-coated Nd-Fe-B composite powder was prepared by thermal decomposition of iron pentacarbonyl in an inert organic solvent in the presence of alkylamine. Though this method is based on a modified solution-phase process to synthesize highly size-controlled iron nanoparticles, it is in turn featured by a suppressed formation of iron nanoparticles to achieve an efficient iron coating solely onto the surfaces of rare-earth magnet powder. The Nd-Fe-B magnetic powder was successfully coated by iron shells whose thicknesses were of the order of submicrometer to micrometer, being tuneable by the amount of initially loaded iron pentacarbonyl in a reaction flask. The amount of the coated iron reached to more than 10 wt.% of the initial Nd-Fe-B magnetic powder, which is practically sufficient to fabricate Nd-Fe-B/α-Fe nanocomposite permanent magnets.

Synthesis and application of iron and zinc doped biochar for removal of p-nitrophenol in wastewater and assessment of the influence of co-existed Pb(II)

International Nuclear Information System (INIS)

Wang, Pei; Tang, Lin; Wei, Xue; Zeng, Guangming; Zhou, Yaoyu; Deng, Yaocheng; Wang, Jingjing; Xie, Zhihong; Fang, Wei

2017-01-01

Highlights: • Iron and zinc doped biochar was developed with larger specific surface area, new generated hydroxyl groups, and beneficial magnetism compared with pristine biochar. • Fe/Zn-biochar presented good performance both for PNP and Pb(II) adsorption as well as their simultaneous removal. • Mechanism of the enhanced adsorption for low concentrations of co-existing PNP and Pb(II) was proposed. - Abstract: The modification of biochar as a low-cost adsorbent is essential to improve its surface properties and shows great potential in water decontamination. The iron and zinc doped sawdust biochar (Fe/Zn-biochar) with large apparent surface area (518.54 m 2 /g) proposed in this work showed good performance for p-nitrophenol (PNP) removal compared with the pristine biochar (P-biochar), iron doped biochar (Fe-biochar) and zinc doped biochar (Zn-biochar) respectively. The batch experiments turned out that Fe/Zn-biochar exhibited larger PNP adsorption capacity under acidic pH solution, and the ionic strength had slightly negative impact on PNP adsorption. The adsorption kinetics and isotherms were discussed, and the experimental data fitted well the Pseudo-second-order equation and Langmuir model. The thermodynamic study indicated that the PNP adsorption was a spontaneous endothermic process. Furthermore, the simultaneous removal for PNP and Pb(II) by Fe/Zn-biochar was investigated. It implied that the adsorption of PNP and Pb(II) at their low concentration might be enhanced by the complexing-bridging mechanism of PNP and Pb(II) ascribing to the affinity between PNP and hydrophobic sites, in addition to the affinity between Pb(II) and oxygen-containing hydrophilic sites on Fe/Zn-biochar surface. However, the predominated competition between PNP and Pb(II) at their high concentrations with Fe/Zn-biochar suppressed their adsorption.

Synthesis and application of iron and zinc doped biochar for removal of p-nitrophenol in wastewater and assessment of the influence of co-existed Pb(II)

Energy Technology Data Exchange (ETDEWEB)

Wang, Pei [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, Hunan (China); Tang, Lin, E-mail: tanglin@hnu.edu.cn [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, Hunan (China); Wei, Xue [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, Hunan (China); Zeng, Guangming, E-mail: zgming@hnu.edu.cn [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, Hunan (China); Zhou, Yaoyu [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, Hunan (China); College of Resources and Environment, Hunan Agricultural University, Changsha 410128 (China); Deng, Yaocheng; Wang, Jingjing; Xie, Zhihong; Fang, Wei [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, Hunan (China)

2017-01-15

Highlights: • Iron and zinc doped biochar was developed with larger specific surface area, new generated hydroxyl groups, and beneficial magnetism compared with pristine biochar. • Fe/Zn-biochar presented good performance both for PNP and Pb(II) adsorption as well as their simultaneous removal. • Mechanism of the enhanced adsorption for low concentrations of co-existing PNP and Pb(II) was proposed. - Abstract: The modification of biochar as a low-cost adsorbent is essential to improve its surface properties and shows great potential in water decontamination. The iron and zinc doped sawdust biochar (Fe/Zn-biochar) with large apparent surface area (518.54 m{sup 2}/g) proposed in this work showed good performance for p-nitrophenol (PNP) removal compared with the pristine biochar (P-biochar), iron doped biochar (Fe-biochar) and zinc doped biochar (Zn-biochar) respectively. The batch experiments turned out that Fe/Zn-biochar exhibited larger PNP adsorption capacity under acidic pH solution, and the ionic strength had slightly negative impact on PNP adsorption. The adsorption kinetics and isotherms were discussed, and the experimental data fitted well the Pseudo-second-order equation and Langmuir model. The thermodynamic study indicated that the PNP adsorption was a spontaneous endothermic process. Furthermore, the simultaneous removal for PNP and Pb(II) by Fe/Zn-biochar was investigated. It implied that the adsorption of PNP and Pb(II) at their low concentration might be enhanced by the complexing-bridging mechanism of PNP and Pb(II) ascribing to the affinity between PNP and hydrophobic sites, in addition to the affinity between Pb(II) and oxygen-containing hydrophilic sites on Fe/Zn-biochar surface. However, the predominated competition between PNP and Pb(II) at their high concentrations with Fe/Zn-biochar suppressed their adsorption.

Instrumental neutron activation analysis of iron and zinc in compact cosmetic products

International Nuclear Information System (INIS)

Kanias, G.D.

1987-01-01

An instrumental neutron activation analysis method is described for the determination of iron and zinc in compact eye shadow, compact face powder and compact rouge make-up cosmetic products. The steps of the procedure are: Irradiation of samples with thermal neutrons, counting of gamma-radioactivity of the radioisotopes of iron and zinc produced by this irradiation and calculation of the concentration of these elements from the gamma-ray spectra of samples and standards. Analysis of the I.A.E.A. standard reference material by this procedure give results in close agreement with certified values. The limit of quantitation is 45 μg for iron and 0.35 μg for zinc. The developed procedure could possibly be established as an official method for the simultaneous determination of iron and zinc in compact cosmetic products. (orig.) [de

IRON-ZINC SUPPLEMENTATION AMONG ADOLESCENT GIRLS AT ELEMENTARY SCHOOL IN KUPANG CITY, EAST TIMOR PROVINCE.

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Yustina Anie Indriastuti Kurniawan

2014-09-01

Full Text Available Anemia is the main micronutrient deficiency problem among adolescent girls in Indonesia. Anemia due to iron deficiency often coexists with zinc deficiency. Both iron deficiency anemia and zinc deficiency can increase the risk of obstetric complications among pregnant women i.e. bleeding during labor and post-partum hemorrhage. Iron-folate supplementation among pregnant women had been conducting since long time ago throughout this country; however, effort to improve the nutritional status particularly among adolescent girls prior to pregnancy is still lack behind. Iron and zinc have antagonistic interaction. Therefore it was challenging to alleviate anemia problem among adolescent girls with appropriate ratio of iron-zinc supplementation, and will give a benefit to improve their nutritional status. This study was aimed to investigate the different ratios of ironzinc supplementation on reducing the prevalence of anemia as improving the nutritional status of adolescent school girls.A female elementary school students age 10-12 years old (n= 137 were screened in rural area of Kupang City, East Timor Province. Subjects were assigned randomly to one of the three groups for daily iron-zinc supplementation for 12 weeks; Group 1 (iron; 60 mg/day, Group 2 (iron and zinc; 30 mg and 15 mg/day, Group 3 (iron and zinc; 60 mg and 15 mg/day. Hemoglobin concentration was measured by cyanmethemoglobin method (Hemocue to determine the prevalence of anemia (Hb level < 120 g/L, while anthropometric assessment was conducted for measuring weight and height to determine the nutritional status. General characteristics was assessed through interview. At base line, 29.1% of subjects suffered from anemia and in general, the prevalence was reduced to around 13.1% after they took iron supplements with or without zinc. Hemoglobin concentration was significantly increased among all subjects euther suffered from anemia or not. The result of this study showed that subject who

Effect of zinc and/or iron supplementations on ICF-level in prepubertal anaemic girls

International Nuclear Information System (INIS)

Ayad, S.K.; Noure Eldin, A.M.

2003-01-01

The study was carried out to evaluate the effects of iron and zinc supplementations separated or combined on levels of iron, zinc and insulin like growth factor-1 (IGF-) in prepuberal girls suffering from iron deficiency anaemia. Hematological and biochemical changes of thirty two anaemic prepubertal girls (mean age 10.5 ± 2.01 year) were compared with normal fifteen girls have the same age. The anaemic girls were divided into three groups according to treatment; groupA (iron, group B(zinc) and group C (iron+zinc)and received supplementations for 8 weeks. Significant decreases in erythrocytic counts (RBCs), hemoglobin (Hb), hematocrit % (Hct%) and reticulocytes%(Rt%) were recorded in blood samples of the three groups before supplementations while non-significant differences were detected in the values of other blood indices. Significant decreases were detected in iron, zinc and IGF-1 levels while non-significant decrease in ferritin was detected in group (A). Erythropoietin and total iron binding capacity (TIBC) showed significant increases in the same group. Total iron binding capacity, iron, zinc and IGF-1 levels showed significant decreases while there were significant increases in erythropoetin and ferritin in group (B). The results revealed that ferritin,iron, zinc and IGF-1 levels were significantly decreased while erythropoietin and TIBC were significantly increased in group (C). After treatment, group (B) showed sligh significant increases in the concentration of Hb, Hct% and Rt%. with non-significant increase in RBCs count but in group (C) the results revealed significant increases in RBCs count, Hb, Hct% and Rt%. Non- significant differences were detected in RBCs count, Hb and Hct% in group (A) while significant increase was detected in Rt% in the same group

Iron from nanocompounds containing iron and zinc is highly bioavailable in rats without tissue accumulation.

Science.gov (United States)

Hilty, Florentine M; Arnold, Myrtha; Hilbe, Monika; Teleki, Alexandra; Knijnenburg, Jesper T N; Ehrensperger, Felix; Hurrell, Richard F; Pratsinis, Sotiris E; Langhans, Wolfgang; Zimmermann, Michael B

2010-05-01

Effective iron fortification of foods is difficult, because water-soluble compounds that are well absorbed, such as ferrous sulphate (FeSO(4)), often cause unacceptable changes in the colour or taste of foods. Poorly water-soluble compounds, on the other hand, cause fewer sensory changes, but are not well absorbed. Here, we show that poorly water-soluble nanosized Fe and Fe/Zn compounds (specific surface area approximately 190 m(2) g(-1)) made by scalable flame aerosol technology have in vivo iron bioavailability in rats comparable to FeSO(4) and cause less colour change in reactive food matrices than conventional iron fortificants. The addition of Zn to FePO(4) and Mg to Fe/Zn oxide increases Fe absorption from the compounds, and doping with Mg also improves their colour. After feeding rats with nanostructured iron-containing compounds, no stainable Fe was detected in their gut wall, gut-associated lymphatics or other tissues, suggesting no adverse effects. Nanosizing of poorly water-soluble Fe compounds sharply increases their absorption and nutritional value.

Iron and zinc bioaccessibility of fermented maize, sorghum and millets from five locations in Zimbabwe.

Science.gov (United States)

Gabaza, Molly; Shumoy, Habtu; Muchuweti, Maud; Vandamme, Peter; Raes, Katleen

2018-01-01

The present study is an evaluation of iron and zinc bioaccessibility of fermented maize, sorghum, pearl millet and finger millet from five different locations in Zimbabwe. Iron and zinc contents ranged between 3.22 and 49.7 and 1.25-4.39mg/100gdm, respectively. Fermentation caused a reduction of between 20 and 88% of phytic acid (PA) while a general increase in soluble phenolic compounds (PC) and a decrease of the bound (PC) was observed. Bioaccessibility of iron and zinc ranged between 2.77 and 26.1% and 0.45-12.8%, respectively. The contribution of the fermented cereals towards iron and zinc absolute requirements ranged between 25 and 411% and 0.5-23% with higher contribution of iron coming from cereals that were contaminated with extrinsic iron. Populations subsisting on cereals could be more at risk of zinc rather than iron deficiency. Copyright © 2017 Elsevier Ltd. All rights reserved.

Relation between Omega 3 Fatty Acid, Iron, Zinc and Treatment of ADHD

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Maryam Shalileh

2014-10-01

Full Text Available In some studies, it is suggested that a number of dietary factors including essential fatty acid, iron and zinc deficiency, may be linked to attention-deficit/hyperactivity-disorder (ADHD. However, the exact mechanism of this relationship is yet unclear. The purpose of this study is to investigate the relationship between omega-3 fatty acids, zinc, and iron in etiopathology and management of ADHD. For the purpose of this study, Science Direct, PubMed, and Medline databases were explored and thirty-four relevant articles in english language were collected. Eighteen out of twenty-two studies confirmed the relationship between omega-3 fatty acid and ADHD. In addition, the role of insufficient store of iron in developing ADHD symptoms and the positive effect of iron supplement in improvement of ADHD behavioral symptoms have been shown. Also, plasma zinc concentration in children with ADHD was lower than the normal population, and the effect of zinc supplement on reducing on attentive-deficit symptoms was contradictory. Although polyunsaturated fatty acids (PUFA and iron supplements are not suggested as main treatment for ADHD, but if future studies confirm the positive results of that, use of these supplements as complementary treatment will affect ADHD symptoms. Considering the little amount of studies on zinc, more research is necessary.

Daily dietary intake of iron, copper, zinc and manganese in a Spanish population.

Science.gov (United States)

Rubio, Carmen; Gutiérrez, Angel José; Revert, Consuelo; Reguera, Juan Ignacio; Burgos, Antonio; Hardisson, Arturo

2009-11-01

To evaluate the daily dietary intake of essential metals in the Canary Islands, the iron, copper, zinc and manganese contents in 420 food and drink samples collected in local markets were analysed by inductively coupled plasma-atomic emission spectrometry (ICP-AES). The estimated daily dietary intakes of iron, copper, zinc and manganese are 13.161 mg/day, 2.098 mg/day, 8.954 mg/day and 2.372 mg/day, respectively. The iron dietary intake was found to be below the recommendations fixed for adult women, while the copper and manganese dietary intakes fulfilled the Recommended Dietary Allowances. The mean daily intake of zinc was below the Recommended Dietary Allowance. Cereals were found to be the food group that contributed most to the intake of these metals. While the island of El-Hierro presented iron, copper, zinc and manganese mean intakes over the estimated intakes for the whole archipelago, Fuerteventura island showed the lowest intakes. Tenerife and Fuerteventura showed the lowest iron intakes, being below the recommendations.

Textural and morphological studies on zinc-iron alloy electrodeposits

Indian Academy of Sciences (India)

Zinc-iron alloy electrodeposits have industrial significance, since they provide better corrosion resistance and with improved mechanical properties when compared to pure zinc coatings. This is due to the unique phase structure of the alloy formed. But this deposition belongs to anomalous deposition, where the ...

Overexpression of ZmIRT1 and ZmZIP3 Enhances Iron and Zinc Accumulation in Transgenic Arabidopsis.

Directory of Open Access Journals (Sweden)

Suzhen Li

Full Text Available Iron and zinc are important micronutrients for both the growth and nutrient availability of crop plants, and their absorption is tightly controlled by a metal uptake system. Zinc-regulated transporters, iron-regulated transporter-like proteins (ZIP, is considered an essential metal transporter for the acquisition of Fe and Zn in graminaceous plants. Several ZIPs have been identified in maize, although their physiological function remains unclear. In this report, ZmIRT1 was shown to be specifically expressed in silk and embryo, whereas ZmZIP3 was a leaf-specific gene. Both ZmIRT1 and ZmZIP3 were shown to be localized to the plasma membrane and endoplasmic reticulum. In addition, transgenic Arabidopsis plants overexpressing ZmIRT1 or ZmZIP3 were generated, and the metal contents in various tissues of transgenic and wild-type plants were examined based on ICP-OES and Zinpyr-1 staining. The Fe and Zn concentration increased in roots and seeds of ZmIRT1-overexpressing plants, while the Fe content in shoots decreased. Overexpressing ZmZIP3 enhanced Zn accumulation in the roots of transgenic plants, while that in shoots was repressed. In addition, the transgenic plants showed altered tolerance to various Fe and Zn conditions compared with wild-type plants. Furthermore, the genes associated with metal uptake were stimulated in ZmIRT1 transgenic plants, while those involved in intra- and inter- cellular translocation were suppressed. In conclusion, ZmIRT1 and ZmZIP3 are functional metal transporters with different ion selectivities. Ectopic overexpression of ZmIRT1 may stimulate endogenous Fe uptake mechanisms, which may facilitate metal uptake and homeostasis. Our results increase our understanding of the functions of ZIP family transporters in maize.

Acceptability of Iron- and Zinc-Biofortified Pearl Millet (ICTP-8203)-Based Complementary Foods among Children in an Urban Slum of Mumbai, India.

Science.gov (United States)

Huey, Samantha Lee; Venkatramanan, Sudha; Udipi, Shobha A; Finkelstein, Julia Leigh; Ghugre, Padmini; Haas, Jere Douglas; Thakker, Varsha; Thorat, Aparna; Salvi, Ashwini; Kurpad, Anura V; Mehta, Saurabh

2017-01-01

Biofortification, a method for increasing micronutrient content of staple crops, is a promising strategy for combating major global health problems, such as iron and zinc deficiency. We examined the acceptability of recipes prepared using iron- and zinc-biofortified pearl millet (FeZnPM) (~80 ppm Fe, ~34 ppm Zn, varietal ICTP-8203), compared to conventional pearl millet (CPM) (~20 ppm Fe, ~19 ppm Zn) in preparation for an efficacy trial. Our objective was to examine the acceptability of FeZnPM compared to CPM among young children and mothers living in the urban slums of Mumbai. Standardized traditional feeding program recipes ( n  = 18) were prepared with either FeZnPM or CPM flour. The weight (g) of each food product was measured before and after consumption by children ( n  = 125) and the average grams consumed over a 3-day period were recorded. Mothers ( n  = 60) rated recipes using a 9-point hedonic scale. Mean intakes and hedonic scores of each food product were compared using t -tests across the two types of pearl millet. There were no statistically significant differences in consumption by children (FeZnPM: 25.27 ± 13.0 g; CPM: 21.72 ± 6.90 g) across the food products ( P  = 0.28). Overall mean hedonic scores for all recipes were between 7 to 9 points. CPM products were rated higher overall (8.22 ± 0.28) compared to FeZnPM products (7.95 ± 0.35) ( P  = 0.01). FeZnPM and CPM were similarly consumed and had high hedonic scores, demonstrating high acceptability in this population. These results support using these varieties of pearl millet in a proposed trial [http://Clinicaltrials.gov ID: NCT02233764; Clinical Trials Registry of India (CTRI), reference number REF/2014/10/007731, CTRI number CTRI/2015/11/006376] testing the efficacy of FeZnPM for improving iron status and growth.

Sublethal effects of cadmium, manganese, lead, zinc and iron on the ...

African Journals Online (AJOL)

The toxicological evaluations of cadmium, iron, manganese, lead and zinc were carried out against albino mice model, Mus musculus. On the basis of 96 hrLC50 value, cadmium (0.47 mM) was found to be the most toxic followed by zinc (2.40 mM), lead (2.42 mM), iron (4.25 mM) and manganese (5.70 mM) was least toxic.

Effect of Iron Fe (II and Fe (III in a Binary System Evaluated Bioluminescent Method

Directory of Open Access Journals (Sweden)

Elena Sorokina

2013-01-01

Full Text Available The effect of iron ions Fe2+ and Fe3+ on the bioluminescent recombinant strain of Escherichia coli in a single-component and binary system. Found that for the bacteria E. coli Fe3+ ions are more toxic than Fe2+. Under the combined effect of iron toxicity increases, the percentage of luminescence quenching increases, but the value is much less than the sum of the indicator for the Fe2+ and Fe3+. The biological effect of insertion of iron is not proportional to their content in the mixture.

Isolation and characterization of Lotus japonicus genes involved in iron and zinc homeostasis

DEFF Research Database (Denmark)

Cvitanich, Cristina; Jensen, Winnie; Sandal, Niels Nørgaard

. Legumes are frequently grown in soil with limited nutrient availability. Plants use finely tuned mechanisms to keep appropriated levels of iron and zinc in each of their organs. Several genes involved in iron and zinc homeostasis have been described in yeast, and a few orthologs have been studied...... in plants. We have used these sequences to search for L. japonicus ESTs and genomic loci that are likely to be involved in iron and zinc metabolism. We have identified sequences corresponding to ferritins, ferric reductases, metal transport proteins of the ZIP family, and cation transporters of the NRAMP......The goal of this project is to find ways to improve the nutritional value of legumes by identifying genes and proteins important for iron and zinc regulation in the model legume Lotus japonicus. Legumes are important staples in the developing world and are a major source of nutrients in many areas...

Zinc phosphate conversion coatings

Science.gov (United States)

Sugama, Toshifumi

1997-01-01

Zinc phosphate conversion coatings for producing metals which exhibit enhanced corrosion prevention characteristics are prepared by the addition of a transition-metal-compound promoter comprising a manganese, iron, cobalt, nickel, or copper compound and an electrolyte such as polyacrylic acid, polymethacrylic acid, polyitaconic acid and poly-L-glutamic acid to a phosphating solution. These coatings are further improved by the incorporation of Fe ions. Thermal treatment of zinc phosphate coatings to generate .alpha.-phase anhydrous zinc phosphate improves the corrosion prevention qualities of the resulting coated metal.

The Effects of Micro Elements of Iron and Zinc on Morphological Characteristics of Mycorrhized Barley (Hordeum vulgare L.

Directory of Open Access Journals (Sweden)

Shahab Khaghani

2016-06-01

Full Text Available Deficiency of micro-nutrients in human diet may cause health problems. To increase the amount of these elements in the edible parts of the plants would eliminate the incidence of these health problems. Thus, the effects of iron and zinc on seed yield and morphological characteristics of mycorrhized barley (cv. Bahman root was studied in Karaj, Iran, during growing season of 2013-14. It was carried out in afactorial experiment based on randomized complete block design with three replications. Treatments consisted two levels of mycorrhiza, non-inoculation (M0 and inoculation with 10 kg/ha of Glomus intraradices (M1, and three levels of iron from Fe-EDDHA (Sequestrene138 as control (F0, 2.5 kg/ha (F1 and 5kg/ha (F2 and three levels of zinc as zinc sulphate (ZnSO4 as control (Z0, 25 kg/ha (Z1 and 50 kg/ha (Z2. The results showed that application of mycorrhiza increased parameters like total root length (TRL, root length density (RLD, specific root length (SLR, root colonization percentage and grain yield by 900.6 cm, 0.52 cm/cm3, 1738.1 cm/g, 5.41% and 1ton/ha respectively. Mean comparisons also revealed that using iron, mycorrhiza and without Zn application increased levels of root dry weight (RDW by 2.81 g.

Large zinc cation occupancy of octahedral sites in mechanically activated zinc ferrite powders

International Nuclear Information System (INIS)

Oliver, S. A.; Harris, V. G.; Hamdeh, H. H.; Ho, J. C.

2000-01-01

The cation site occupancy of a mechanically activated nanocrystalline zinc ferrite powder was determined as (Zn 0.55 2+ Fe 0.18 3+ ) tet [Zr 0.45 2+ Fe 1.82 3+ ] oct O 4 through analysis of extended x-ray absorption fine structure measurements, showing a large redistribution of cations between sites compared to normal zinc ferrite samples. The overpopulation of cations in the octahedral sites was attributed to the ascendance in importance of the ionic radii over the crystal energy and bonding coordination in determining which interstitial sites are occupied in this structurally disordered powder. Slight changes are observed in the local atomic environment about the zinc cations, but not the iron cations, with respect to the spinel structure. The presence of Fe 3+ on both sites is consistent with the measured room temperature magnetic properties. (c) 2000 American Institute of Physics

Nicotianamine Secretion for Zinc Excess Tolerance

NARCIS (Netherlands)

Aarts, M.G.M.

2014-01-01

Plants acquire micronutrients such as iron (Fe), zinc (Zn), manganese, or copper from soil. These micronutrients are often not readily available and they need to be mobilized to the proper free ionic form in order to be taken up by plant roots. Perhaps the only exception to this is the uptake of Fe

Crystal structure and spin state of mixed-crystals of iron with zinc and cobalt for the assembled complexes bridged by 1,3-bis(4-pyridyl)propanes

Energy Technology Data Exchange (ETDEWEB)

Dote, Haruka [Hiroshima University, Graduate School of Science (Japan); Nakashima, Satoru, E-mail: snaka@hiroshima-u.ac.jp [Hiroshima University, Natural Science Center for Basic Research and Development (Japan)

2012-03-15

Mixed crystals of cobalt and zinc were synthesized using 1,3-bis(4-pyridyl)propane (bpp) as bridging ligand and NCS{sup - } as anion. Red crystals and blue crystals were obtained. Powder X-ray diffraction patterns showed that the former is in 2D interpenetrated structure, while the latter has the same structure with Zn(NCS){sub 2}(bpp). Iron ion was introduced both into the red crystals and blue crystals of the mixed crystals of cobalt with zinc. {sup 57}Fe Moessbauer spectrum of the red crystals showed a main doublet of Fe{sup II} high-spin state at 78 K, while the spectrum of blue crystals did not show Fe{sup II} high-spin state at 78 K.

Crystal structure and spin state of mixed-crystals of iron with zinc and cobalt for the assembled complexes bridged by 1,3-bis(4-pyridyl)propanes

International Nuclear Information System (INIS)

Dote, Haruka; Nakashima, Satoru

2012-01-01

Mixed crystals of cobalt and zinc were synthesized using 1,3–bis(4–pyridyl)propane (bpp) as bridging ligand and NCS  −  as anion. Red crystals and blue crystals were obtained. Powder X-ray diffraction patterns showed that the former is in 2D interpenetrated structure, while the latter has the same structure with Zn(NCS) 2 (bpp). Iron ion was introduced both into the red crystals and blue crystals of the mixed crystals of cobalt with zinc. 57 Fe Mössbauer spectrum of the red crystals showed a main doublet of Fe II high-spin state at 78 K, while the spectrum of blue crystals did not show Fe II high-spin state at 78 K.

Zinc toxicity among galvanization workers in the iron and steel industry.

Science.gov (United States)

El Safty, Amal; El Mahgoub, Khalid; Helal, Sawsan; Abdel Maksoud, Neveen

2008-10-01

Galvanization is the process of coating steel or cast iron pieces with zinc, allowing complete protection against corrosion. The ultimate goal of this work was to assess the effect of occupational exposure to zinc in the galvanization process on different metals in the human body and to detect the association between zinc exposure and its effect on the respiratory system. This study was conducted in 111 subjects in one of the major companies in the iron and steel industry. There were 61 subjects (workers) who were involved in the galvanization process. Fifty adult men were chosen as a matched reference group from other departments of the company. All workers were interviewed using a special questionnaire on occupational history and chest diseases. Ventilatory functions and chest X rays were assessed in all examined workers. Also, complete blood counts were performed, and serum zinc, iron, copper, calcium, and magnesium levels were tested. This study illustrated the relation between zinc exposure in the galvanization process and high zinc levels among exposed workers, which was associated with a high prevalence rate of metal fume fever (MFF) and low blood copper and calcium levels. There was no statistically significant difference between the exposed and control groups with regards to the magnesium level. No long-term effect of metals exposure was detected on ventilatory functions or chest X rays among the exposed workers.

Extraction of copper zinc and iron from hydrochloric acid solutions by means of different extractants

Energy Technology Data Exchange (ETDEWEB)

Zhivkova, Svetlana [Institute of Chemical Engineering - Bulgarian Academy of Sciences, Sofia (Bulgaria)

2011-07-01

The extraction of copper, zinc and iron from hydrochloric acid solutions has been studied. The experiments have been carried out using various solvents, involving different extraction mechanisms – solvating, anion-exchange, cation-exchange, bifunctional . Mixtures of these extractants have been also used. The extraction properties of these extractant mixtures toward copper, zinc and iron, the effect of used modifiers and diluents have been also investigated. Key words: Copper, Zinc, Iron, Extraction, Extractant, Modifier, Diluent.

Isotope-aided studies of the bioavailability of iron from Myanmar diets

Energy Technology Data Exchange (ETDEWEB)

Naing, Khin Maung [Department of Medical Research, Yangon (Myanmar). Nutrition Research Div.; Khin, Myo [Department of Medical Research, Yangon, (Myanmar). Nuclear Medicine Research Div.

1994-12-31

A study was conducted to determine the dietary intakes and serum levels of iron and zinc in twenty apparently healthy Myanmar adults (10 males and 10 females), using atomic absorption spetrophotometry. The mean iron intake of females was found to be lower than the FAO/WHO recommended allowance whereas for men it was found to be adequate. The mean serum iron concentration in females was found to be significantly lower than in males (p < 0.05). It was observed that zinc intakes of males was significantly higher than in females (p < 0.01) but there was no significant difference in serum zinc level between the two groups. Dietary zinc intakes of both groups were found to be low. There was a weak positive correlation between dietary intake and serum concentrations of these minerals. Laboratory scale production of iron-fortified salt containing 1 mg of Fe/g salt was conducted by mixing 5g of FeSO{sub 4{center_dot}}7H{sub 2}O, and 5g of sodium-hexa-metaphosphate thoroughly and then the mixture was again mixed with 1 kg of salt. This was done in July 1992. Stability of iron-fortified salt (i.e. change in colour of salt) as well as ferrous and ferric iron content of iron-fortified salt, were determined at monthly intervals. Iron-fortified salt was found to be stable up to the time of report writing, i.e. 3rd week of October, 1992. The ferrous iron content of salt was found to range between 0.95 to 0.98 mg Fe/g salt. Bioavailability studies of iron from two types of standard meals, one containing staple rice, 32 g of fish, water cress, watery fish paste and cucumber, and another containing boiled peas in place of fish, were conducted on two groups of male subjects using {sup 59}Fe as an extrinsic tag. Bioavailability studies of iron from the above two types of meals cooked with iron-fortified salt (1 mg/g salt) were also conducted on the same groups of subjects using {sup 59}Fe as an extrinsic tag. Reference dose absorption of iron will be conducted. This work is in progress.

Zinc ferrite nanoparticles as perspective functional materials for applications in casting technologies

Directory of Open Access Journals (Sweden)

A. Kmita

2017-01-01

Full Text Available In this article it discuss on possible application of magnetic oxide nanoparticles, namely non-stoichiometric zinc ferrite nanoparticles as a functionalizing agent in foundry processes. Thermal analysis showed a weight loss of the sample at 1 273 K in an amount of 7,7 %, which is a result of the following processes taking place in different temperature ranges. Upon its thermal treatment Zn0,4Fe2,6O4 decomposes to zinc oxide and iron (III oxide (first stage and next to iron (II,III oxide and oxygen (second stage. The degree of decomposition was expressed as Fe2+ / Fetotal. Mössbauer spectroscopy showed that the over 30 % of Fe3+ present in starting material was reduced to Fe2+.

Hydrometallurgical process for recovering iron sulfate and zinc sulfate from baghouse dust

Science.gov (United States)

Zaromb, Solomon; Lawson, Daniel B.

1994-01-01

A process for recovering zinc/rich and iron-rich fractions from the baghouse dust that is generated in various metallurgical operations, especially in steel-making and other iron-making plants, comprises the steps of leaching the dust by hot concentrated sulfuric acid so as to generate dissolved zinc sulfate and a precipitate of iron sulfate, separating the precipitate from the acid by filtration and washing with a volatile liquid, such as methanol or acetone, and collecting the filtered acid and the washings into a filtrate fraction. The volatile liquid may be recovered distillation, and the zinc may be removed from the filtrate by alternative methods, one of which involves addition of a sufficient amount of water to precipitate hydrated zinc sulfate at 10.degree. C., separation of the precipitate from sulfuric acid by filtration, and evaporation of water to regenerate concentrated sulfuric acid. The recovery of iron may also be effected in alternative ways, one of which involves roasting the ferric sulfate to yield ferric oxide and sulfur trioxide, which can be reconverted to concentrated sulfuric acid by hydration. The overall process should not generate any significant waste stream.

Selectivity in the oxidative dehydrogenation of butene on zinc-iron oxide catalyst

Energy Technology Data Exchange (ETDEWEB)

Kung, H.H.; Kundalkar, B.; Kung, M.C.; Cheng, W.H.

1980-02-21

Adsorption, temperature-programed desorption, and pulse reaction studies of cis-2-butene and butadiene on spinel zinc ferrite by previously described methods provided evidence that the selectivity for oxidative dehydrogenation of butenes increases when zinc is added to the iron oxide catalyst because selective oxidation and complete oxidation proceed on separate sites, as they do on pure iron; because the density of sites for selective oxidation is higher and the density of sites for complete combustion is lower than on pure iron oxide; and because the activity of the combustion sites is lower.

Scaling-up biofortified beans high in iron and zinc through the school-feeding program

NARCIS (Netherlands)

Beintema, Joni J.S.; Gallego-Castillo, Sonia; Londoño-Hernandez, Luis F.; Restrepo-Manjarres, José; Talsma, Elise F.

2018-01-01

Iron and zinc deficiencies are global health problems, affecting mostly pregnant women and young children. In 2016, biofortified iron and zinc beans were introduced in Colombia. The incorporation of biofortified beans into the national school-feeding program could facilitate adoption and potentially

Large zinc cation occupancy of octahedral sites in mechanically activated zinc ferrite powders

Energy Technology Data Exchange (ETDEWEB)

Oliver, S. A. [Center for Electromagnetic Research, Northeastern University, Boston, Massachusetts 02115 (United States); Harris, V. G. [Complex Materials Section, Code 6342, Naval Research Laboratory, Washington, DC 20375 (United States); Hamdeh, H. H. [Department of Physics, Wichita State University, Wichita, Kansas 67260 (United States); Ho, J. C. [Department of Physics, Wichita State University, Wichita, Kansas 67260 (United States)

2000-05-08

The cation site occupancy of a mechanically activated nanocrystalline zinc ferrite powder was determined as (Zn{sub 0.55}{sup 2+}Fe{sub 0.18}{sup 3+}){sub tet}[Zr{sub 0.45}{sup 2+}Fe{sub 1.82}{sup 3+}]{sub oct}O{sub 4} through analysis of extended x-ray absorption fine structure measurements, showing a large redistribution of cations between sites compared to normal zinc ferrite samples. The overpopulation of cations in the octahedral sites was attributed to the ascendance in importance of the ionic radii over the crystal energy and bonding coordination in determining which interstitial sites are occupied in this structurally disordered powder. Slight changes are observed in the local atomic environment about the zinc cations, but not the iron cations, with respect to the spinel structure. The presence of Fe{sup 3+} on both sites is consistent with the measured room temperature magnetic properties. (c) 2000 American Institute of Physics.

Biofortification of wheat grain with iron and zinc: integrating novel genomic resources and knowledge from model crops

Directory of Open Access Journals (Sweden)

Philippa eBorrill

2014-02-01

Full Text Available Wheat, like many other staple cereals, contains low levels of the essential micronutrients iron and zinc. Up to two billion people worldwide suffer from iron and zinc deficiencies, particularly in regions with predominantly cereal-based diets. Although wheat flour is commonly fortified during processing, an attractive and more sustainable solution is biofortification, which requires developing new varieties of wheat with inherently higher iron and zinc content in their grains. Until now most studies aimed at increasing iron and zinc content in wheat grains have focused on discovering natural variation in progenitor or related species. However, recent developments in genomics and transformation have led to a step change in targeted research on wheat at a molecular level. We discuss promising approaches to improve iron and zinc content in wheat using knowledge gained in model grasses. We explore how the latest resources developed in wheat, including sequenced genomes and mutant populations, can be exploited for biofortification. We also highlight the key research and practical challenges that remain in improving iron and zinc content in wheat.

Vitamin A, iron and zinc deficiency in Indonesia : micronutrient interactions and effects of supplementation

NARCIS (Netherlands)

Dijkhuizen, M.A.; Wieringa, F.T.

2001-01-01

The research described in this thesis was concerned with vitamin A, iron and zinc deficiency in pregnant and lactating women and in infants. The effects of supplementation withβ-carotene, iron and zinc on micronutrient status, growth, pregnancy outcome and immune function, and interactions

Iron and zinc absorption from weaning foods prepared from germinated cereals and legumes

International Nuclear Information System (INIS)

Kuizon, M.D.

1992-01-01

Iron deficiency anaemia is a public health problem in the Philippines especially in infants, children and pregnant women. The immediate cause is inadequate intake of available iron to meet increased iron requirements. Iron supplementation studies on pregnant women showed improvement in haemoglobin level and reduction of prevalence of anaemia. A project on iron fortification of rice with ferrous sulphate is going on. It is proposed to study iron and zinc absorption from weaning food prepared from germinated rice: mungbean, germinated rice: cowpea, and germinated corn:mungbean to support the finding that these formulations will alleviate not only protein-energy malnutrition but contribute to improvement of iron status as well since iron contents are higher and anti-nutritional factors (phytates and tannin) are either reduced or eliminated. This study aims to measure the iron and zinc absorption from weaning foods prepared from germinated rice-mungbean, germinated rice-cowpea, and germinated corn-mungbean and to indicate usefullness of modifying local foods to improve iron absorption. 24 refs, 4 figs

Isotope aided studies on the bioavailability of iron and zinc from human diets consumed in India

International Nuclear Information System (INIS)

Raghuramulu, N.; Das, P.; Prasad, P.

1994-01-01

Total iron, and zinc, in-vitro ionizable iron and soluble zinc were estimated by the chemical and extrinsic isotope tag methods for comparison in various foodstuffs as such, and after processing, and also in diets. It has been observed that the values got were more or less similar by both the procedures. The in-vitro ionizable iron in groundnut was low with low total iron as well. Total iron and ionizable iron were also estimated in commonly consumed breakfast preparations. The effect of tea on ionizable iron when taken along with breakfast was also investigated. It was found that different breakfast preparations varied narrowly with regards to total iron (4.6-7.2 mg) and percent ionizable iron (25%-33%). However, tea had a pronounced effect on ionizable iron resulting in inhibition to various extents. Total and soluble zinc were analyzed in green leafy vegetables and groundnut. Though the total zinc was low and similar in both foodstuffs, the percent soluble Zn was found to be high in green leafy vegetables as compared to groundnut. Tannin and ascorbic acid contents were estimated in a few foodstuffs. Tannin content in green leafy vegetables was found to be about 150 mg. Ascorbic acid concentration was high in cereals (except in rice) and whole pulses. The split pulses (dals) were found to be poor sources of ascorbic acid. Ionizable iron and soluble zinc were found to increase to various extents on processing. Germination was found to increase ascorbic acid, whereas it had no effect on tannin. (author). 4 figs, 8 tabs

Nanocompounds of iron and zinc: their potential in nutrition

NARCIS (Netherlands)

Zimmermann, M.B.; Hilty, F.M.

2011-01-01

Recent studies suggest nanostructured oxides and phosphates of Fe and atomically mixed Fe/Zn may be useful for nutritional applications. These compounds may have several advantages over existing fortificants, such as ferrous sulfate (FeSO(4)), NaFeEDTA and electrolytic iron. Because of their very

High purity Fe3O4 from Local Iron Sand Extraction

Science.gov (United States)

Gunanto, Y. E.; Izaak, M. P.; Jobiliong, E.; Cahyadi, L.; Adi, W. A.

2018-04-01

Indonesia has a long coastline and is rich with iron sand. The iron sand is generally rich in various elements such as iron and titanium. One of the products processing of the iron sand mineral is iron (II) (III) oxide (magnetite Fe3O4). The stages of purification process to extracting magnetite phase and discarding the other phases has been performed. Magnetite phase analysis of ironsand extraction retrieved from Indonesia have been investigated. The result of analysis element of iron sand shows that it consists of majority Fe around 65 wt%. However, there are still 17 impurities such as Ti, Al, Ce, Co, Cr, Eu, La, Mg, Mn, Na, Sc, Sm, Th, V, Yb, and Zn. After extraction process, Fe element content increases up to 94%. The iron sand powder after milling for 10 hours and separating using a magnetic separator, the iron sand powders are dissolved in acid chloride solution to form a solution of iron chloride, and this solution is sprinkled with sodium hydroxide to obtain fine powders of Fe3O4. The fine powders which formed were washed with de-mineralization water. The X-ray diffraction pattern shows that the fine powders have a single phase of Fe3O4. The analysis result shows that the sample has the chemical formula: Fe3O4 with a cubic crystal system, space group: Fd-3m and lattice parameters: a = b = c = 8.3681 (1) Å, α = β = γ = 90°. The microstructure analysis shows that the particle of Fe3O4 homogeneously shaped like spherical. The magnetic properties using vibrating sample magnetometer shows that Fe3O4 obtained have ferromagnetic behavior with soft magnetic characteristics. We concluded that this purification of iron sand had been successfully performed to obtain fine powders of Fe3O4 with high purity.

A method for determination of [Fe3+]/[Fe2+] ratio in superparamagnetic iron oxide

Science.gov (United States)

Jiang, Changzhao; Yang, Siyu; Gan, Neng; Pan, Hongchun; Liu, Hong

2017-10-01

Superparamagnetic iron oxide nanoparticles (SPION), as a kind of nanophase materials, are widely used in biomedical application, such as magnetic resonance imaging (MRI), drug delivery, and magnetic field assisted therapy. The magnetic property of SPION has close connection with its crystal structure, namely it is related to the ratio of Fe3+ and Fe2+ which form the SPION. So a simple way to determine the content of the Fe3+ and Fe2+ is important for researching the property of SPION. This review covers a method for determination of the Fe3+ and Fe2+ ratio in SPION by UV-vis spectrophotometry based the reaction of Fe2+ and 1,10-phenanthroline. The standard curve of Fe with R2 = 0.9999 is used for determination the content of Fe2+ and total iron with 2.5 mL 0.01% (w/v) SPION digested by HCl, pH = 4.30 HOAc-NaAc buffer 10 mL, 0.01% (w/v) 1,10-phenanthroline 5 mL and 10% (w/v) ascorbic acid 1 mL for total iron determine independently. But the presence of Fe3+ interfere with obtaining the actual value of Fe2+ (the error close to 9%). We designed a calibration curve to eliminate the error by devising a series of solution of different ratio of [Fe3+]/[Fe2+], and obtain the calibration curve. Through the calibration curve, the error between the measured value and the actual value can be reduced to 0.4%. The R2 of linearity of the method is 0.99441 and 0.99929 for Fe2+ and total iron respectively. The error of accuracy of recovery and precision of inter-day and intra-day are both lower than 2%, which can prove the reliability of the determination method.

Impact of sorghum processing on phytate, phenolic compounds and in vitro solubility of iron and zinc in thick porridges

OpenAIRE

Kayodé, A.P.P.; Linnemann, A.R.; Nout, M.J.R.; Boekel, van, M.A.J.S.

2007-01-01

This study focussed on the impact of process variables on levels of phytate and phenolic compounds, and in vitro solubility of iron (Fe) and zinc (Zn) in sorghum porridges, a major staple in semi-arid tropics. The aim was to identify practices that enhance the mineral availability in this type of staple food. We studied the example of the West African porridge `dibou' for which the processing methods involve grain cleaning, milling, sieving and cooking. Regional variations occur in the proces...

Corrosion resistance of Zn-Co-Fe alloy coatings on high strength steel

NARCIS (Netherlands)

Lodhi, Z.F.; Mol, J.M.C.; Hovestad, A.; Hoen-Velterop, L. 't; Terryn, H.; Wit, J.H.W.de

2009-01-01

The corrosion properties of electrodeposited zinc-cobalt-iron (Zn-Co-Fe) alloys (up to 40 wt.% Co and 1 wt.% Fe) on steel were studied by using various electrochemical techniques and compared with zinc (Zn) and cadmium (Cd) coatings in 3.5% NaCl solution. It was found that with an increase in Co

Binding of zinc and iron to wheat bread, wheat bran, and their components.

Science.gov (United States)

Ismail-Beigi, F; Faraji, B; Reinhold, J G

1977-10-01

Wholemeal wheat bread decreases the availability and intestinal absorption of divalent metals. To define this action further, binding of zinc in vitro to a wheat wholemeal bread (Tanok), dephytinized Tanok, and cellulose was determined at pH 5.0 to 7.5. Zinc binding by each was highly pH-dependent and reached a maximum at pH 6.5 to 7.5. Removal of phytate from Tanok did not reduce its binding capability. Wheat bran at pH 6.5 and 6.8 bound 72% of iron (0.5 microgram/ml of solution) and 82.5% of zinc (1.43 microgram/ml solution), respectively. Lignin and two of the hemicellulose fractions of wheat bran and high binding capabilities for zinc (85.6, 87.1, and 82.1%, respectively) whereas a third had a lower zinc-binding capability (38.7%). Binding of zinc to various celluloses and dextrans is also demonstrated. Formation of complexes of these metals with wheat fiber can explain, at least in part, the decreased availability of dietary iron and zinc in wholemeal wheat bread.

Thermodynamic Characterization of Iron Oxide-Aqueous Fe(2+) Redox Couples.

Science.gov (United States)

Gorski, Christopher A; Edwards, Rebecca; Sander, Michael; Hofstetter, Thomas B; Stewart, Sydney M

2016-08-16

Iron is present in virtually all terrestrial and aquatic environments, where it participates in redox reactions with surrounding metals, organic compounds, contaminants, and microorganisms. The rates and extent of these redox reactions strongly depend on the speciation of the Fe2+ and Fe3+ phases, although the underlying reasons remain unclear. In particular, numerous studies have observed that Fe2+ associated with iron oxide surfaces (i.e., oxide-associated Fe2+) often reduces oxidized contaminants much faster than aqueous Fe2+ alone. Here, we tested two hypotheses related to this observation by determining if solutions containing two commonly studied iron oxides—hematite and goethite—and aqueous Fe2+ reached thermodynamic equilibrium over the course of a day. We measured reduction potential (EH) values in solutions containing these oxides at different pH values and aqueous Fe2+ concentrations using mediated potentiometry. This analysis yielded standard reduction potential (EH0) values of 768 ± 1 mV for the aqueous Fe2+–goethite redox couple and 769 ± 2 mV for the aqueous Fe2+–hematite redox couple. These values were in excellent agreement with those calculated from existing thermodynamic data, and the data could be explained by the presence of an iron oxide lowering EH values of aqueous Fe3+/Fe2+ redox couples.

Iron and Vitamin C Co-Supplementation Increased Serum Vitamin C Without Adverse Effect on Zinc Level in Iron Deficient Female Youth

Directory of Open Access Journals (Sweden)

Mohammad Reza Khoshfetrat

2014-01-01

Full Text Available Background: Iron supplementation can decrease the absorption of zinc and influence other antioxidants levels such as vitamin C. This study aimed to investigate the effect of iron supplements alone and in combination with vitamin C on zinc and vitamin C status in iron deficient female students. Methods: In a double-blind randomized clinical trail, 60 iron deficient students were selected from 289 volunteers residing in dormitory. After matching, subjects were randomly assigned into two groups: Group I (50 mg elemental iron supplements and Group II (50 mg elemental iron + 500 mg ascorbic acid. Serum ferritin, iron, serum zinc, and plasma vitamin C concentrations were measured by using enzyme-linked immunosorbent assay, spectrophotometer, atomic absorption spectrometer, and colorimeter, respectively after 6 and 12 weeks supplementation. Student′s t-test and repeated measures analysis of variance were applied to analyze the data using SPSS software. Results: Serum zinc levels had no significant differences between 2 groups at the baseline; however, its concentration decreased from 80.9 ± 4.2-68.9 ± 2.7 μg/dl to 81.2 ± 4.5-66.1 ± 2.9 μg/dl (P < 0.001 in Groups I and II, respectively after 6 weeks of supplementation. Continuous supplementation increased serum zinc concentration to baseline levels (79.0 ± 2.9 μg/dl; P < 0.01 in Group I and 70.5 ± 3.1 μg/dl in Group II following 12 weeks of supplementation. Plasma vitamin C increased from 3 ± 0/1-3.3 ± 0.2 mg/dl to 2.7 ± 0. 1-4.2 ± 0.2 mg/dl (P < 0.01 in Groups I and II, respectively. At the end of study, plasma vitamin C significantly increased from 3.3 ± 0.3-4.7 ± 0.3 (P < 0.01 to 4.2 ± 0.2-7.1 ± 0.2 (P < 0.001 in Groups I and II, respectively. Conclusions: Iron supplementation with and without vitamin C led to reduction in serum Zn in iron-deficient female students after 6 weeks. However, the decreasing trend stops after repletion of iron stores and Zn levels returned to the

In vitro solubility of calcium, iron and zinc in relation to phytic acid levels in rice-based consumer products in China.

Science.gov (United States)

Liang, Jianfen; Han, Bei-Zhong; Nout, M J Robert; Hamer, Robert J

2010-02-01

In vitro solubility of calcium, iron and zinc in relation to phytic acid (PA) levels in 30 commercial rice-based foods from China was studied. Solubility of minerals and molar ratios of PA to minerals varied with degrees of processing. In primary products, [PA]/[Ca] values were less than 5 and [PA]/[Fe] and [PA]/[Zn] similarly ranged between 5 and 74, with most values between 20 and 30. [PA]/[mineral] molar ratios in intensively processed products were lower. Solubility of calcium ranged from 0% to 87%, with the lowest in brown rice (12%) and the highest in infant foods (50%). Iron solubility in two-thirds of samples was lower than 30%, and that of zinc narrowly ranged from 6% to 30%. Solubility of minerals was not significantly affected by [PA]/[mineral]. At present, neither primary nor intensively processed rice-based products are good dietary sources of minerals. Improvements should be attempted by dephytinization, mineral fortification or, preferably, combination of both.

Influence of iron ions on the structural properties of some inorganic glasses

International Nuclear Information System (INIS)

Music, S.; Gotic, M.; Popovic, S.; Grzeta, B.

1987-01-01

The effects of iron on the structural properties of Zn-borosilicate glass and Pb-metaphosphate glass were studied using x-ray diffraction, 57 Fe Moessbauer spectroscopy and IR spectroscopy. At high concentration of iron the crystallization of zinc ferrite in the glass matrix takes place. X-ray diffraction and 57 Fe Moessbauer spectroscopy showed that the amount of zinc ferrite in Zn-borosilicate glass decreases. In Pb-metaphosphate glass doped with high concentration of α-Fe 2 O 3 , the crystallization of Fe 3 (PO 4 ) 2 is pronounced. The assignments of IR band positions and the corresponding interpretation are given. The importance of this study for the technology of vitrification of high-level radioactive wastes is emphasized. (author) 31 refs.; 6 figs,.; 6 tabs

ARTICLE - Path analysis of iron and zinc contents and others traits in cowpea

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Jeane de Oliveira Moura

2012-12-01

Full Text Available The objective of this study was to estimate the direct and indirect effects of agronomic and culinary traits on iron and zinc contents in 11 cowpea populations. Correlations between traits were estimated and decomposed into direct and indirect effects using path analysis. For the study populations, breeding for larger grain size, higher number of grains per pod, grain yield, reduced cooking time, and number of days to flowering can lead to decreases in the levels of iron and zinc in the grain. Genetic gains for the iron content can be obtained by direct selection for protein content by indirect effects on the number of grains per pod, 100-grain weight and grain yield. The positive direct effect of grain size and protein content on the zinc content indicates the possibility of simultaneous gain by combined selection of these traits.

Energy dispersive x-ray fluorescence spectrometric determination of phosphorus, calcium, iron, zinc, and strontium in human bones

International Nuclear Information System (INIS)

Ohta, Akishige; Matsubayashi, Takashi; Itoman, Moritoshi

1981-01-01

Phosphorus, calcium, iron, zinc and strontium in a human bone extracted by surgery were determined by energy dispersive X-ray fluorescence spectrometry. The bone was decomposed with nitric acid, then diluted with water. A specific quantity of the solution was naturally dried on polyethylene film, and subjected to X-ray analysis. For determining the calibration curves in a mixture of phosphorus, calcium, iron, zinc and strontium, for the analysis of phosphorus and calcium, germanium was used as the secondary target and aluminum as the filter; and for the analysis of iron, zinc and strontium, molybdenum and molybdenum-aluminum were used, respectively. Consequently, the calibration curves were able to be obtained with high precision in the ranges from 5 to 500 μg of phosphorus, from 1 to 50 μg of calcium and from 0.1 to 1.0 μg of iron, zinc and strontium. In this way, in 1 mg of the human bone by wet weight, phosphorus, calcium, iron, zinc and strontium were able to be determined. (J.P.N.)

Medicago truncatula Zinc-Iron Permease6 provides zinc to rhizobia-infected nodule cells.

Science.gov (United States)

Abreu, Isidro; Saéz, Ángela; Castro-Rodríguez, Rosario; Escudero, Viviana; Rodríguez-Haas, Benjamín; Senovilla, Marta; Larue, Camille; Grolimund, Daniel; Tejada-Jiménez, Manuel; Imperial, Juan; González-Guerrero, Manuel

2017-11-01

Zinc is a micronutrient required for symbiotic nitrogen fixation. It has been proposed that in model legume Medicago truncatula, zinc is delivered by the root vasculature into the nodule and released in the infection/differentiation zone. There, transporters must introduce this element into rhizobia-infected cells to metallate the apoproteins that use zinc as a cofactor. MtZIP6 (Medtr4g083570) is an M. truncatula Zinc-Iron Permease (ZIP) that is expressed only in roots and nodules, with the highest expression levels in the infection/differentiation zone. Immunolocalization studies indicate that it is located in the plasma membrane of nodule rhizobia-infected cells. Down-regulating MtZIP6 expression levels with RNAi does not result in any strong phenotype when plants are fed mineral nitrogen. However, these plants displayed severe growth defects when they depended on nitrogen fixed by their nodules, losing of 80% of their nitrogenase activity. The reduction of this activity was likely an indirect effect of zinc being retained in the infection/differentiation zone and not reaching the cytosol of rhizobia-infected cells. These data are consistent with a model in which MtZIP6 would be responsible for zinc uptake by rhizobia-infected nodule cells in the infection/differentiation zone. © 2017 John Wiley & Sons Ltd.

Sulfur dioxide leaching of spent zinc-carbon-battery scrap

Energy Technology Data Exchange (ETDEWEB)

Avraamides, J.; Senanayake, G.; Clegg, R. [A.J. Parker Cooperative Research Centre for Hydrometallurgy, Murdoch University, Perth, WA 6150 (Australia)

2006-09-22

Zinc-carbon batteries, which contain around 20% zinc, 35% manganese oxides and 10% steel, are currently disposed after use as land fill or reprocessed to recover metals or oxides. Crushed material is subjected to magnetic separation followed by hydrometallurgical treatment of the non-magnetic material to recover zinc metal and manganese oxides. The leaching with 2M sulfuric acid in the presence of hydrogen peroxide recovers 93% Zn and 82% Mn at 25{sup o}C. Alkaline leaching with 6M NaOH recovers 80% zinc. The present study shows that over 90% zinc and manganese can be leached in 20-30min at 30{sup o}C using 0.1-1.0M sulfuric acid in the presence of sulfur dioxide. The iron extraction is sensitive to both acid concentration and sulfur dioxide flow rate. The effect of reagent concentration and particle size on the extraction of zinc, manganese and iron are reported. It is shown that the iron and manganese leaching follow a shrinking core kinetic model due to the formation of insoluble metal salts/oxides on the solid surface. This is supported by (i) the decrease in iron and manganese extraction from synthetic Fe(III)-Mn(IV)-Zn(II) oxide mixtures with increase in acid concentration from 1M to 2M, and (ii) the low iron dissolution and re-precipitation of dissolved manganese and zinc during prolonged leaching of battery scrap with low sulfur dioxide. (author)

Serum zinc, copper and iron status of children with coeliac disease on three months of gluten-free diet with or without four weeks of zinc supplements: a randomised controlled trial.

Science.gov (United States)

Negi, K; Kumar, R; Sharma, L; Datta, S P; Choudhury, M; Kumar, P

2018-04-01

Data about the effect of zinc supplementation with gluten-free diet on normalisation of plasma zinc, copper and iron in patients with coeliac disease are scanty. We evaluated the effect of zinc supplementation on serum zinc, copper and iron levels in patients with coeliac disease, by randomising 71 children newly diagnosed with coeliac disease into two groups: Group A = gluten-free diet (GFD); and Group B = gluten-free diet with zinc supplements (GFD +Zn). The rise in iron and zinc was significantly higher in the latter, but the mean rise of copper levels was slightly higher in the former, but the difference was not significant.

Determination of iron, copper, manganese and zinc in the soils, grapes and wines of the Azores

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María Teresa Ribeiro de Lima

2004-06-01

Full Text Available This paper describes the determination of iron, copper, manganese and zinc in the soils, grapes and wines of the three viticultural regions of the Azores. Iron, copper and zinc were determined by flame atomic absorption spectrometry and manganese by graphite furnace atomic absorption. The concentrations of the four elements differed in soils of the three regions; there was no difference in the concentration in grapes, whereas significant differences were observed for the wines as regards the amounts of iron, manganese and zinc. The concentrations of these four elements in wine correspond with the mean values observed for other European regions.

Effects of calcium carbonate and hydroxyapatite on zinc and iron retention in postmenopausal women

International Nuclear Information System (INIS)

Dawson-Hughes, B.; Seligson, F.H.; Hughes, V.A.

1986-01-01

We measured the effect of calcium carbonate and hydroxyapatite on whole-body retention of zinc-65 in 11 and iron-59 in 13 healthy, postmenopausal women. In a single-blind, controlled, crossover study, each subject, on three occasions, ingested a standard test meal supplemented with iron-59 or zinc-65 and capsules containing placebo or 500 mg elemental calcium as calcium carbonate or hydroxyapatite. Whole-body countings were performed prior to, 30 min after, and 2 wk after each meal. Mean (SEM) zinc retention was 18.1 +/- 1.0% with placebo (control) and did not vary significantly with calcium carbonate (110.0 +/- 8.6% of control) or hydroxyapatite (106.0 +/- 7.9% of control). Iron retention, 6.3 +/- 2.0% with placebo, was significantly reduced with both calcium carbonate (43.3 +/- 8.8% of control, p = 0.002) and hydroxyapatite (45.9 +/- 10.0% of control, p = 0.003). Iron absorption may be significantly reduced when calcium supplements are taken with meals

Higher Fe{sup 2+}/total Fe ratio in iron doped phosphate glass melted by microwave heating

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Mandal, Ashis K., E-mail: ashis@cgcri.res.in [CSIR-Central Glass and Ceramic Research Institute, 196 Raja S.C. Mullick Road, Kolkata 700032 (India); Sinha, Prasanta K. [CSIR-Central Glass and Ceramic Research Institute, 196 Raja S.C. Mullick Road, Kolkata 700032 (India); Das, Dipankar [UGC-DAE Consortium for Scientific Research, Kolkata 700098 (India); Guha, Chandan [Department of Chemical Engineering, Jadavpur University, Kolkata 700032 (India); Sen, Ranjan [CSIR-Central Glass and Ceramic Research Institute, 196 Raja S.C. Mullick Road, Kolkata 700032 (India)

2015-03-15

Highlights: • Iron doped phosphate glasses prepared using microwave heating and conventional heating under air and reducing atmosphere. • Presence of iron predominantly in the ferrous oxidation state in all the glasses. • Significant concentrations of iron in the ferrous oxidation state on both octahedral and tetrahedral sites in all the glasses. • Ratio of Fe{sup 2+} with total iron is found higher in microwave prepared glasses in comparison to conventional prepared glasses. - Abstract: Iron doped phosphate glasses containing P{sub 2}O{sub 5}–MgO–ZnO–B{sub 2}O{sub 3}–Al{sub 2}O{sub 3} were melted using conventional resistance heating and microwave heating in air and under reducing atmosphere. All the glasses were characterised by UV–Vis–NIR spectroscopy, Mössbauer spectroscopy, thermogravimetric analysis and wet colorimetry analysis. Mössbauer spectroscopy revealed presence of iron predominantly in the ferrous oxidation state on two different sites in all the glasses. The intensity of the ferrous absorption peaks in UV–Vis–NIR spectrum was found to be more in glasses prepared using microwave radiation compared to the glasses prepared in a resistance heating furnace. Thermogravimetric analysis showed increasing weight gain on heating under oxygen atmosphere for glass corroborating higher ratio of FeO/(FeO + Fe{sub 2}O{sub 3}) in glass melted by direct microwave heating. Wet chemical analysis also substantiated the finding of higher ratio Fe{sup +2}/ΣFe in microwave melted glasses. It was found that iron redox ratio was highest in the glasses prepared in a microwave furnace under reducing atmosphere.

Effect of Sulfur on Liquidus Temperatures in the ZnO-"FeO"-Al2O3-CaO-SiO2-S System in Equilibrium with Metallic Iron

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Zhao, Baojun; Hayes, Peter C.; Jak, Evgueni

2011-10-01

The phase equilibria in the ZnO-"FeO"-Al2O3-CaO-SiO2-S system have been determined experimentally in equilibrium with metallic iron. A pseudoternary section of the form ZnO-"FeO"-(Al2O3+CaO+SiO2) for CaO/SiO2 = 0.71 (weight), (CaO+SiO2)/Al2O3 = 5.0 (weight), and fixed 2.0 wt pct S concentration has been constructed. It was found that the addition of 2.0 wt pct S to the liquid extends the spinel primary phase field significantly and decreases the size of the wustite primary phase field. The liquidus temperature in the wustite primary phase field is decreased by approximately 80 K and the liquidus temperature in the spinel primary phase field is decreased by approximately 10 K with addition of 2.0 wt pct S in the composition range investigated. It was also found that iron-zinc sulfides are present in some samples in the spinel primary phase field, which are matte appearing at low zinc concentrations and sphalerite (Zn,Fe)S at higher zinc concentrations. The presence of sulfur in the slag has a minor effect on the partitioning of ZnO between the wustite and liquid phases but no effect on the partitioning of ZnO between the spinel and liquid phases.

Photoreduction of Terrigenous Fe-Humic Substances Leads to Bioavailable Iron in Oceans.

Science.gov (United States)

Blazevic, Amir; Orlowska, Ewelina; Kandioller, Wolfgang; Jirsa, Franz; Keppler, Bernhard K; Tafili-Kryeziu, Myrvete; Linert, Wolfgang; Krachler, Rudolf F; Krachler, Regina; Rompel, Annette

2016-05-23

Humic substances (HS) are important iron chelators responsible for the transport of iron from freshwater systems to the open sea, where iron is essential for marine organisms. Evidence suggests that iron complexed to HS comprises the bulk of the iron ligand pool in near-coastal waters and shelf seas. River-derived HS have been investigated to study their transport to, and dwell in oceanic waters. A library of iron model compounds and river-derived Fe-HS samples were probed in a combined X-ray absorption spectroscopy (XAS) and valence-to-core X-ray emission spectroscopy (VtC-XES) study at the Fe K-edge. The analyses performed revealed that iron complexation in HS samples is only dependent on oxygen-containing HS functional groups, such as carboxyl and phenol. The photoreduction mechanism of Fe III -HS in oceanic conditions into bioavailable aquatic Fe II forms, highlights the importance of river-derived HS as an iron source for marine organisms. Consequently, such mechanisms are a vital component of the upper-ocean iron biogeochemistry cycle.

Nanosized zero-valent iron as Fenton-like reagent for ultrasonic-assisted leaching of zinc from blast furnace sludge

Energy Technology Data Exchange (ETDEWEB)

Mikhailov, Ivan, E-mail: ivan.mikhailov@misis.ru [National University of Science and Technology “MISiS”, 4 Leninskiy prospekt, Moscow, 119049 (Russian Federation); Komarov, Sergey [Tohoku University, 6-6-02 Aramaki Aza Aoba, Aoba-ku, Sendai, 980-8576 (Japan); Levina, Vera; Gusev, Alexander; Issi, Jean-Paul; Kuznetsov, Denis [National University of Science and Technology “MISiS”, 4 Leninskiy prospekt, Moscow, 119049 (Russian Federation)

2017-01-05

Highlights: • nZVI is used as Fenton-like reagent for activation of Zn leaching from the BFS. • nZVI has positive effect on kinetics of Zn leaching though with some loss of efficiency. • A complex ultrasonic-assisted method for BFS recycling is proposed. - Abstract: Ultrasonic-assisted sulphuric acid leaching combined with a Fenton-like process, utilizing nanoscale zero-valent iron (nZVI), was investigated to enhance the leaching of zinc from the blast furnace sludge (BFS). The leaching of iron (Fe) and zinc (Zn) from the sludge was investigated using Milli-Q water/BFS ratio of 10 and varying the concentration of hydrogen peroxide, sulphuric acid, the temperature, the input energy for ultrasound irradiation, and the presence or absence of nZVI as a Fenton reagent. The results showed that with 1 g/l addition of nZVI and 0.05 M of hydrogen peroxide, the kinetic rate of Zn leaching increased with a maximum dissolution degree of 80.2%, after 5 min treatment. In the absence of nZVI, the maximum dissolution degree of Zn was 99.2%, after 15 min treatment with 0.1 M of hydrogen peroxide. The rate of Zn leaching at several concentrations of hydrogen peroxide is accelerated in the presence of nZVI although a reduction in efficiency was observed. The loss of Fe was no more than 3%. On the basis of these results, the possible route for BFS recycling has been proposed (BFS slurry mixed with sulphuric acid and hydrogen peroxide is recirculated under ultrasonic irradiation then separated).

Different Phosphorus Supplies Altered the Accumulations and Quantitative Distributions of Phytic Acid, Zinc, and Iron in Rice (Oryza sativa L.) Grains.

Science.gov (United States)

Su, Da; Zhou, Lujian; Zhao, Qian; Pan, Gang; Cheng, Fangmin

2018-02-21

Development of rice cultivars with low phytic acid (lpa) is considered as a primary strategy for biofortification of zinc (Zn) and iron (Fe). Here, two rice genotypes (XS110 and its lpa mutant) were used to investigate the effect of P supplies on accumulations and distributions of PA, Zn, and Fe in rice grains by using hydroponics and detached panicle culture system. Results showed that higher P level increased grain PA concentration on dry matter basis (g/kg), but it markedly decreased PA accumulation on per grain basis (mg/grain). Meanwhile, more P supply reduced the amounts and bioavailabilities of Zn and Fe both in milled grains and in brown grains. Comparatively, lpa mutant was more susceptive to exogenous P supply than its wild type. Hence, the appropriate P fertilizer application should be highlighted in order to increase grain microelement (Zn and Fe) contents and improve nutritional quality in rice grains.

Iron and zinc absorption from weaning foods prepared from germinated cereals and legumes using isotope tracers

Energy Technology Data Exchange (ETDEWEB)

Valdez, D H; Kuizon, M D; Marero, L M; Mallillin, A C; Cruz, E M; Madriaga, J R [Department of Science and Technology, Manila (Philippines). Food and Nutrition Research Inst.

1994-12-31

Iron bioavailability from weaning foods prepared from 70:30 combination of germinated rice:mungbean (GRM); germinated rice: cowpea (GRC) and germinated corn:mungbean (GCM) was determined by radioisotopic measurements of iron absorption in human subjects. The gruels were prepared as plain with sugar and flavoring labeled by the extrinsic tag method, and served as hot porridge. It was estimated that iron-deficient infants would absorb 3.5% from GRM, 4.9% from GRC and 5.6% from GCM. Differences between absorption among the weaning foods were not statistically significant. Planning of diets for these age group should include other sources of iron especially heme. Zinc absorption from the weaning food formulations will be studied by the in vitro and in vivo methods. For the in vivo method on human subjects, the absorption of zinc will be determined from the measurement of the whole body retention of the isotope 14 days after intake of the labeled mean. Serum zinc level will be determined to assess the zinc status of the subjects. (author). 23 refs, 1 fig., 4 tabs.

Iron and zinc absorption from weaning foods prepared from germinated cereals and legumes using isotope tracers

International Nuclear Information System (INIS)

Valdez, D.H.; Kuizon, M.D.; Marero, L.M.; Mallillin, A.C.; Cruz, E.M.; Madriaga, J.R.

1994-01-01

Iron bioavailability from weaning foods prepared from 70:30 combination of germinated rice:mungbean (GRM); germinated rice: cowpea (GRC) and germinated corn:mungbean (GCM) was determined by radioisotopic measurements of iron absorption in human subjects. The gruels were prepared as plain with sugar and flavoring labeled by the extrinsic tag method, and served as hot porridge. It was estimated that iron-deficient infants would absorb 3.5% from GRM, 4.9% from GRC and 5.6% from GCM. Differences between absorption among the weaning foods were not statistically significant. Planning of diets for these age group should include other sources of iron especially heme. Zinc absorption from the weaning food formulations will be studied by the in vitro and in vivo methods. For the in vivo method on human subjects, the absorption of zinc will be determined from the measurement of the whole body retention of the isotope 14 days after intake of the labeled mean. Serum zinc level will be determined to assess the zinc status of the subjects. (author). 23 refs, 1 fig., 4 tabs

Expression of zinc transporter genes in rice as influenced by zinc-solubilizing Enterobacter cloacae strain ZSB14

Directory of Open Access Journals (Sweden)

Selvaraj eKrithika

2016-04-01

Full Text Available Zinc (Zn deficiency in major food crops has been considered as an important factor affecting the crop production and subsequently the human health. Rice (Oryza sativa is sensitive to Zn deficiency and thereby causes malnutrition to most of the rice-eating Asian populations. Application of zinc solubilizing bacteria (ZSB could be a sustainable agronomic approach to increase the soil available Zn which can mitigate the yield loss and consequently the nutritional quality of rice. Understanding the molecular interactions between rice and unexplored ZSB is useful for overcoming Zn deficiency problems. In the present study, the role of zinc solubilizing bacterial strain Enterobacter cloacae strain ZSB14 on regulation of Zn-regulated transporters and iron (Fe-regulated transporter-like protein (ZIP genes in rice under iron sufficient and deficient conditions was assessed by quantitative real-time reverse transcription PCR. The expression patterns of OsZIP1, OsZIP4 and OsZIP5 in root and shoot of rice were altered due to the Zn availability as dictated by Zn sources and ZSB inoculation. Fe sufficiency significantly reduced the root and shoot OsZIP1 expression, but not the OsZIP4 and OsZIP5 levels. Zinc oxide in the growth medium up-regulated all the assessed ZIP genes in root and shoot of rice seedlings. When ZSB was inoculated to rice seedlings grown with insoluble zinc oxide in the growth medium, the expression of root and shoot OsZIP1, OsZIP4 and OsZIP5 was reduced. In the absence of zinc oxide, ZSB inoculation up-regulated OsZIP1 and OsZIP5 expressions. Zinc nutrition provided to the rice seedling through ZSB-bound zinc oxide solubilization was comparable to the soluble zinc sulphate application which was evident through the ZIP genes’ expression and the Zn accumulation in root and shoot of rice seedlings. These results demonstrate that zinc solubilizing bacteria could play a crucial role in zinc fertilization and fortification of rice.

Combined in situ zymography, immunofluorescence, and staining of iron oxide particles in paraffin-embedded, zinc-fixed tissue sections.

Science.gov (United States)

Haeckel, Akvile; Schoenzart, Lena; Appler, Franziska; Schnorr, Joerg; Taupitz, Matthias; Hamm, Bernd; Schellenberger, Eyk

2012-01-01

Superparamagnetic iron oxide particles are used as potent contrast agents in magnetic resonance imaging. In histology, these particles are frequently visualized by Prussian blue iron staining of aldehyde-fixed, paraffin-embedded tissues. Recently, zinc salt-based fixative was shown to preserve enzyme activity in paraffin-embedded tissues. In this study, we demonstrate that zinc fixation allows combining in situ zymography with fluorescence immunohistochemistry (IHC) and iron staining for advanced biologic investigation of iron oxide particle accumulation. Very small iron oxide particles, developed for magnetic resonance angiography, were applied intravenously to BALB/c nude mice. After 3 hours, spleens were explanted and subjected to zinc fixation and paraffin embedding. Cut tissue sections were further processed to in situ zymography, IHC, and Prussian blue staining procedures. The combination of in situ zymography as well as IHC with subsequent Prussian blue iron staining on zinc-fixed paraffin-embedded tissues resulted in excellent histologic images of enzyme activity, protease distribution, and iron oxide particle accumulation. The combination of all three stains on a single section allowed direct comparison with only moderate degradation of fluorescein isothiocyanate-labeled substrate. This protocol is useful for investigating the biologic environment of accumulating iron oxide particles, with excellent preservation of morphology.

Zinc and resin bonded NdFeB magnets

International Nuclear Information System (INIS)

Leonowicz, M.; Kaszuwara, W.

2002-01-01

Zinc and resin bonded NdFeB magnets were processed. Basic magnetic parameters as well as compressive strength were evaluated versus annealing temperature and volume fraction of the bonding agent. For the zinc bonded magnets phase composition was investigated. The additional NdZn 5 phase was found in the Zn bonded magnets after annealing. Comparison of the Zn and resin bonded magnets reveals higher remanence for the former and higher coercivity for the latter. For the Zn and resin bonded magnets, 15 wt.% Zn / 370 o C and 7-10 wt.% resin were chosen as the optimal processing parameters. (author)

Effects of separate delivery of zinc or zinc and vitamin A on hemoglobin response, growth, and diarrhea in young Peruvian children receiving iron therapy for anemia.

Science.gov (United States)

Alarcon, Karl; Kolsteren, Patrick W; Prada, Ana M; Chian, Ana M; Velarde, Ruth E; Pecho, Iris L; Hoeree, Tom F

2004-11-01

Anemia is the most prevalent nutritional deficiency in the world. Attempts to improve iron indexes are affected by deficiency of and interaction between other micronutrients. Our goal was to assess whether zinc added to iron treatment alone or with vitamin A improves iron indexes and affects diarrheal episodes. This was a randomized, placebo-controlled, double-blind trial conducted in Peru. Anemic children aged 6-35 mo were assigned to 3 treatment groups: ferrous sulfate (FS; n = 104), ferrous sulfate and zinc sulfate (FSZn; n = 109), and ferrous sulfate, zinc sulfate, and vitamin A (FSZnA; n = 110). Vitamin A or its placebo was supplied only once; iron and zinc were provided under supervision >/=1 h apart 6 d/wk for 18 wk. The prevalence of anemia was 42.97%. The increase in hemoglobin in the FS group (19.5 g/L) was significantly less than that in the other 2 groups (24.0 and 23.8 g/L in the FSZn and FSZnA groups, respectively). The increase in serum ferritin in the FS group (24.5 mug/L) was significantly less than that in the other 2 groups (33.0 and 30.8 mug/L in the FSZn and FSZnA groups, respectively). The median duration of diarrhea and the mean number of stools per day was significantly higher in the FS group than in other 2 groups (P < 0.005). Adding zinc to iron treatment increases hemoglobin response, improves iron indexes, and has positive effects on diarrhea. No additional effect of vitamin A was found.

X-ray emission spectroscopy study of iron silicate catalyst FeZSM-5

International Nuclear Information System (INIS)

Csencsits, R.; Lyman, C.E.; Gronsky, R.

1988-03-01

Iron silicate analogs of the zeolite ZMS-5 may be directly synthesized from iron silicate gels in a manner which differs slightly from the alumino-silicate ZSM-5. The resultant white, crystalline iron silicate is referred to as FeZSM-5 in the as-synthesized form. Thermal treatment removes the organic crystal-directing agent and moves some of the framework iron into non-framework sites producing the calcined form of the molecular sieve FeZSM-5. Homogeneity in the distribution of catalytic iron throughout the particles is desired in an optimal catalyst. Distribution of the iron throughout the framework in the as-synthesized forms would affect the final distribution of catalytic iron in the calcined and steamed forms; thus, the iron distribution throughout the as-synthesized and calcined forms of FeZSM-5 were studied using the high spatial resolution on the analytical electron microscope. 7 refs., 3 figs

The Influence of Iron and Zinc Supplementation on the Bioavailability of Provitamin A Carotenoids from Papaya Following Consumption of a Vitamin A-Deficient Diet.

Science.gov (United States)

Kana-Sop, Marie Modestine; Gouado, Inocent; Achu, Mercy Bih; Van Camp, John; Amvam Zollo, Paul Henri; Schweigert, Florian J; Oberleas, Donald; Ekoe, Tetanye

2015-01-01

Iron deficiency anemia, zinc and vitamin A deficiencies are serious public health problems in Cameroon, as in many developing countries. Local vegetables which are sources of provitamin A carotenoids (PACs) can be used to improve vitamin A intakes. However, traditional meals are often unable to cover zinc and iron needs. The aim of this study was to determine the bioavailability of 3 PACs (α-carotene, β-carotene, and β-cryptoxanthin) in young men, who were fed with a vitamin A-free diet and received iron and zinc supplementation. Twelve healthy participants were divided into three groups and were supplemented with elemental iron (20 mg of iron fumarate), 20 mg of zinc sulfate or iron+zinc (20 mg of iron in the morning and 20 mg of zinc in the evening) for 11 d. They were given a vitamin A- and PAC-free diet from the 6th to the 11th day, followed by a test meal containing 0.55 kg of freshly peeled papaya as a source of PACs. Blood samples were collected four times successively on the 11th day (the test meal day), at T0 (just after the test meal), after 2 h (T2), after 4 h (T4) and after 7 h (T7). Ultracentrifugation was used to isolate serum chylomicrons. Retinol appearance and PAC postprandial concentrations were determined. The supplementation with zinc, iron and iron+zinc influenced the chylomicron appearance of retinol and PACs differently as reflected by retention times and maximum absorption peaks. Iron led to highest retinol levels in the chylomicron. Zinc and iron+zinc supplements were best for optimal intact appearance of α-carotene, β-carotene and β-cryptoxanthin respectively. Supplementation with iron led to the greatest bioavailability of PACs from papaya and its conversion to retinol.

Association of Maternal Diet With Zinc, Copper, and Iron Concentrations in Transitional Human Milk Produced by Korean Mothers

Science.gov (United States)

Kim, Ji-Myung; Lee, Ji-Eun; Cho, Mi Sook; Kang, Bong Soo; Choi, Hyeon

2016-01-01

The aims of this study were to evaluate zinc, copper, and iron concentrations in the transitory milk of Korean lactating mothers and to investigate the relationship between these concentrations and maternal diet. Human milk samples were collected between 5 and 15 days postpartum from 96 healthy, lactating mothers in postpartum care centers in Seoul, Korea. Dietary intake during lactation was determined based on a 3-day dietary record. The mean zinc, copper, and iron concentrations in the human milk samples collected were 3.88 ± 1.74 mg/L, 0.69 ± 0.25 mg/L, and 5.85 ± 8.53 mg/L, respectively. The mothers who consumed alcoholic beverages during pregnancy had tended to have lower concentrations of zinc and copper, as well as significantly lower concentrations of iron, in their milk (p < 0.047). In contrast, the mothers who took daily supplements had much higher iron concentrations in their milk (p = 0.002). Dietary intakes of zinc, copper, and iron during lactation did not affect the concentrations of zinc, copper, and iron in the milk samples analyzed. Intakes of vitamin C, selenium, and iodine were associated with the concentration of copper in the milk samples analyzed, and consumption of food categorized as 'meat and meat products' was positively associated with the concentration of zinc. Consumption of rice was the top contributor to the concentrations of all three minerals. In conclusion, associations between maternal diet and nutrient concentrations in transitory human milk can provide useful information, particularly in regard to infant growth. PMID:26839873

Cobalt-, zinc- and iron-bound forms of adenylate kinase (AK) from the sulfate-reducing bacterium Desulfovibrio gigas: purification, crystallization and preliminary X-ray diffraction analysis

International Nuclear Information System (INIS)

Kladova, A. V.; Gavel, O. Yu.; Mukhopaadhyay, A.; Boer, D. R.; Teixeira, S.; Shnyrov, V. L.; Moura, I.; Moura, J. J. G.; Romão, M. J.; Trincão, J.; Bursakov, S. A.

2009-01-01

Adenylate kinase (AK) from D. gigas was purified and crystallized in three different metal-bound forms: Zn 2+ –AK, Co 2+ –AK and Fe 2+ –AK. Adenylate kinase (AK; ATP:AMP phosphotransferase; EC 2.7.4.3) is involved in the reversible transfer of the terminal phosphate group from ATP to AMP. AKs contribute to the maintenance of a constant level of cellular adenine nucleotides, which is necessary for the energetic metabolism of the cell. Three metal ions, cobalt, zinc and iron(II), have been reported to be present in AKs from some Gram-negative bacteria. Native zinc-containing AK from Desulfovibrio gigas was purified to homogeneity and crystallized. The crystals diffracted to beyond 1.8 Å resolution. Furthermore, cobalt- and iron-containing crystal forms of recombinant AK were also obtained and diffracted to 2.0 and 3.0 Å resolution, respectively. Zn 2+ –AK and Fe 2+ –AK crystallized in space group I222 with similar unit-cell parameters, whereas Co 2+ –AK crystallized in space group C2; a monomer was present in the asymmetric unit for both the Zn 2+ –AK and Fe 2+ –AK forms and a dimer was present for the Co 2+ –AK form. The structures of the three metal-bound forms of AK will provide new insights into the role and selectivity of the metal in these enzymes

Bioavailability of Iron, Zinc, Phytate and Phytase Activity during Soaking and Germination of White Sorghum Varieties

Science.gov (United States)

Afify, Abd El-Moneim M. R.; El-Beltagi, Hossam S.; Abd El-Salam, Samiha M.; Omran, Azza A.

2011-01-01

The changes in phytate, phytase activity and in vitro bioavailability of iron and zinc during soaking and germination of three white sorghum varieties (Sorghum bicolor L. Moench), named Dorado, Shandweel-6, and Giza-15 were investigated. Sorghum varieties were soaked for 20 h and germinated for 72 h after soaking for 20 h to reduce phytate content and increase iron and zinc in vitro bioavailability. The results revealed that iron and zinc content was significantly reduced from 28.16 to 32.16% and 13.78 to 26.69% for soaking treatment and 38.43 to 39.18% and 21.80 to 31.27% for germination treatments, respectively. Phytate content was significantly reduced from 23.59 to 32.40% for soaking treatment and 24.92 to 35.27% for germination treatments, respectively. Phytase enzymes will be activated during drying in equal form in all varieties. The results proved that the main distinct point is the change of phytase activity as well as specific activity during different treatment which showed no significant differences between the varieties used. The in vitro bioavailability of iron and zinc were significantly improved as a result of soaking and germination treatments. PMID:22003395

Noninvasive analysis of skin iron and zinc levels in beta-thalassemia major and intermedia

International Nuclear Information System (INIS)

Gorodetsky, R.; Goldfarb, A.; Dagan, I.; Rachmilewitz, E.A.

1985-01-01

Diagnostic x-ray spectrometry, a method based on x-ray fluorescence analysis, was used for noninvasive determination of iron and zinc in two distinct skin areas, representing predominantly dermal and epidermal tissues, in 56 patients with beta-thalassemia major and intermedia. The mean iron levels in the skin of patients with beta-thalassemia major and intermedia were elevated by greater than 200% and greater than 50%, respectively, compared with control values. The zinc levels of both skin areas examined were within the normal range. The data indicate that the rate and number of blood transfusions, which correlated well with serum ferritin levels (r . 0.8), are not the only factors that determine the amount of iron deposition in the skin (r less than 0.6). Other sources of iron intake contribute to the total iron load in the tissues, particularly in patients who are not given multiple transfusions. The noninvasive quantitation of skin levels may reflect the extent of iron deposition in major parenchymal organs. Repeated DXS examinations of the skin could monitor the clearance of iron from the tissues of patients with iron overload in the course of therapy with chelating agents

Influence of heat processing on the bioaccessibility of zinc and iron from cereals and pulses consumed in India.

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Hemalatha, Sreeramaiah; Platel, Kalpana; Srinivasan, Krishnapura

2007-01-01

Influence of heat processing on the bioaccessibility of zinc and iron from food grains consumed in India was evaluated. Cereals - rice (Oryza sativa), finger millet (Eleusine coracana), sorghum (Sorghum vulgare), wheat (Triticum aestivum), and maize (Zea mays), and pulses - chickpea (Cicer arietinum) - whole and decorticated, green gram (Phaseolus aureus) - whole and decorticated, decorticated black gram (Phaseolus mungo), decorticated red gram (Cajanus cajan), cowpea (Vigna catjang), and French bean (Phaseolus vulgaris) were examined for zinc and iron bioaccessibility by employing an in vitro dialysability procedure. Both pressure-cooking and microwave heating were tested for their influence on mineral bioaccessibility. Zinc bioaccessibility from food grains was considerably reduced upon pressure-cooking, especially in pulses. Among cereals, pressure-cooking decreased zinc bioaccessibility by 63% and 57% in finger millet and rice, respectively. All the pressure-cooked cereals showed similar percent zinc bioaccessibility with the exception of finger millet. Bioaccessibility of zinc from pulses was generally lower as a result of pressure-cooking or microwave heating. The decrease in bioaccessibility of zinc caused by microwave heating ranged from 11.4% in chickpea (whole) to 63% in cowpea. Decrease in zinc bioaccessibility was 48% in pressure-cooked whole chickpea, 45% and 55% in pressure-cooked or microwave-heated whole green gram, 32% and 22% in pressure-cooked or microwave-heated decorticated green gram, and 45% in microwave-heated black gram. Iron bioaccessibility, on the other hand, was significantly enhanced generally from all the food grains studied upon heat treatment. Thus, heat treatment of grains produced contrasting effect on zinc and iron bioaccessibility.

Iron, folacin, vitamin B12 and zinc status and immune response in the elderly

International Nuclear Information System (INIS)

Henry-Christian, J.R.; Johnson, A.A.; Walters, C.S.; Greene, E.J.; Lindsey, A.A.

1986-01-01

The relationships of iron, folacin, vitamin B 12 and zinc status to cell-mediated immune response were investigated among 125 healthy, elderly persons (60-87 years of age). Plasma ferritin, plasma and red cell folate, and plasma vitamin B 12 levels were assayed immuno-radiometrically. Plasma and hair zinc levels were determined by atomic absorption spectroscopy. Immune response was determined by transformation of peripheral blood lymphocytes after stimulation with phytohemagglutinin (PHA) and concanavalin A (con A), and in mixed lymphocyte reaction. Deficiencies of iron, folacin vitamin B 12 and zinc were each associated (independently) with significantly lower lymphocyte responses to PHA and con A, and mixed lymphocyte reaction (P 12 or zinc. Further, they suggest that deficiencies of these nutrients may play a role in the depression of cell-mediated immunity with age, which in turn may lead to increased susceptibility to infectious diseases and cancer in the elderly

Bioavailability of iron and zinc in green leafy vegetables growing in river side and local areas of Allahabad district

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Bhawna Srivastava

2014-01-01

Full Text Available Introduction: Green Leafy Vegetables (GLVs are the treasure trove of many micronutrients.Objective: The aim of the study is to find out the commonly growing vegetables in river side and local areas of Allahabad district and to access the bioavailability of iron and zinc in selected green leafy vegetables of river side and local areas of Allahabad district.Methods: Five to four commonly grown green leafy vegetables were selected from the Arailghat, Baluaghat, Gaughat, Mahewa, Muirabad, Rajapur, Rasullabad for the study. Total iron and zinc in sample were estimated by AOAC (2005 and bioavailability of zinc and iron from various food samples was determined in vitro method described by Luten (1996. Appropriate statistical technique was adopted for analysis of study.Result: Soya leaves, Radish leaves, Amaranth, Spinach were grown in both the areas except Kulpha and Karamwa, which are commonly grown in river side area. There was a significant difference between the bioavailability of iron and zinc in GLV grown in local and river side area.Conclusion: Hence it can be concluded that there is a contamination of heavy metals which binds with the iron and zinc and make them less bioavailable in the selected GLV.

Effect of different home-cooking methods on the bioaccessibility of zinc and iron in conventionally bred cowpea (Vigna unguiculata L. Walp) consumed in Brazil.

Science.gov (United States)

Pereira, Elenilda J; Carvalho, Lucia M J; Dellamora-Ortiz, Gisela M; Cardoso, Flávio S N; Carvalho, José L V

2016-01-01

The cowpea (Vigna unguiculata L. Wap.) is an excellent source of iron and zinc. However, iron from plant sources is poorly absorbed compared with iron from animal sources. The objective of this study was to evaluate iron and zinc bioaccessibility in cowpea cultivars after processing. Zinc and iron bioaccessibilities in cowpea samples were determined based on an in vitro method involving simulated gastrointestinal digestion with suitable modifications. When water-soaked beans were cooked in a regular pan, the highest percentage of bioaccessible iron obtained was 8.92%, whereas when they were cooked in a pressure cooker without previous soaking, the highest percentage was 44.33%. Also, the percentage of bioaccessible zinc was 52.78% when they were cooked in a regular pan without prior soaking. Higher percentages of bioaccessible iron were found when cooking was done in a pressure cooker compared with regular pan cooking. In all cultivars, cooking of cowpea beans in both pressure cooker and in a regular pan yielded higher percentages of bioaccessible zinc compared with availability of bioaccessible iron. Iron bioaccessibility values suggest that cooking in a regular pan did not have a good effect on iron availability, since the percentage of bioaccessible iron was lower than that of zinc. The determination of iron and zinc bioaccessibility makes it possible to find out the actual percentage of absorption of such minerals and allows the development of efficient strategies for low-income groups to access foods with high levels of these micronutrients.

Trace Elements Iron, Copper and Zinc in Vitreous of Patients with Various Vitreoretinal Diseases

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Sulochana Konerirajapuram

2004-01-01

Full Text Available Purpose: To measure the concentrations of iron, copper and zinc in human vitreous and to interpret their levels with various vitreoretinal diseases like proliferative diabetic retinopathy, retinal detachment, intraocular foreign body, Eales′ disease and macular hole. Methods: Undiluted vitreous fluid collected during pars plana vitrectomy was used to measure trace elements using an atomic absorption spectrophotometer. Results: The level of vitreous iron increased threefold in Eales′ disease (1.85 ± 0.36 pg/ml, 2.5-fold in proliferative diabetic retinopathy (1.534 ± 0.17 pg/ml and 2.3-fold in eyes with intraocular foreign body (1.341 ± 0.25 pg/ml when compared with macular hole (0.588 ± 0.16 pg/ml. This was statistically significant (P < 0.05. Zinc was found to be low in Eales′ disease (0.57 ± 0.22 pg/ml when compared with other groups, though the difference was not statistically significant. Conclusion: The increased level of iron with decreased zinc content in Eales′ disease confirms the earlier reported oxidative stress mechanism for the disease. In proliferative diabetic retinopathy and intraocular foreign body the level of iron increases. This is undesirable as iron can augment glycoxidation, which can lead to increased susceptibility to oxidative damage, in turn causing vitreous liquefaction, posterior vitreous detachment and ultimately retinal detachment and vision loss

Formation cross section of iron-60 with reactor neutrons in 59Fe(n, γ)60Fe reaction

International Nuclear Information System (INIS)

Sato, T.; Suzuki, T.

1993-01-01

Ingrowth of 60 Co radioactivity in an iron sample irradiated in a nuclear reactor has been measured for determination of formation cross section of 60 Fe in the 59 Fe(n, γ) 60 Fe reaction with reactor neutrons. After 5 years cooling, the irradiated iron was purified from 60 Co and other radioactive nuclides by an anion exchange separation method and isopropyl ether extraction in hydrochloric acid. The amount of 60 Co ingrowth was measured by γ-spectrometry using a Ge-detector coupled to a multichannel pulse height analyzer 4 years after the purification of iron. Neutron flux of the irradiation position was calculated from the amount of 55 Fe produced. The observed value of 12.5 ± 2.8 barn is slightly greater than reported value for burnup cross section of 59 Fe(n, x)X, where x refers γ, α, d, p and 2n, and X is any nuclide produced by the above reactions. (author) 8 refs.; 2 tabs

Isotope - aided studies of the bioavailability of iron and zinc from human diets consumed in Poland

International Nuclear Information System (INIS)

Rafalski, H.

1992-01-01

The main aims of the study were: 1) the evaluation of iron and zinc status in women of Lodz aged 18-45 years, 2) adaptation of the whole body counter to in vivo measurements absorption of iron given to the gastro-intestinal tract of volunteers and 3) in rat model estimation iron bioavailability from fortified wheat flour combined with products usually consumed in Poland. During five months investigations thirty seven women were examined each one twice in two months interval. Following variables were measured: iron and zinc in blood serum, in public and scalp hair and in food, taste acuity score, serum ferritin, hemoglobin, total iron binding capacity, red blood cells, mean corpuscular concentration and corpuscular volume. Prevalence of iron deficiency and iron deficient anemia were assessed by two models in terms of the depression of serum ferritin and hemoglobin concentrations. 64 refs, 6 figs, 23 tabs

Geochemistry of the furnace magnetite bed, Franklin, New Jersey, and the relationship between stratiform iron oxide ores and stratiform zinc oxide-silicate ores in the New Jersey highlands

Science.gov (United States)

Johnson, C.A.; Skinner, B.J.

2003-01-01

The New Jersey Highlands terrace, which is an exposure of the Middle Proterozoic Grenville orogenic belt located in northeastern United States, contains stratiform zinc oxide-silicate deposits at Franklin and Sterling Hill and numerous massive magnetite deposits. The origins of the zinc and magnetite deposits have rarely been considered together, but a genetic link is suggested by the occurrence of the Furnace magnetite bed and small magnetite lenses immediately beneath the Franklin zinc deposit. The Furnace bed was metamorphosed and deformed along with its enclosing rocks during the Grenvillian orogeny, obscuring the original mineralogy and obliterating the original rock fabrics. The present mineralogy is manganiferous magnetite plus calcite. Trace hydrous silicates, some coexisting with fluorite, have fluorine contents that are among the highest ever observed in natural assemblages. Furnace bed calcite has ??13C values of -5 ?? 1 per mil relative to Peedee belemnite (PDB) and ??18O values of 11 to 20 per mil relative to Vienna-standard mean ocean water (VSMOW). The isotopic compositions do not vary as expected for an original siderite layer that decarbonated during metamorphism, but they are consistent with nearly isochemical metamorphism of an iron oxide + calcite protolith that is chemically and minerlogically similar to iron-rich sediments found near the Red Sea brine pools and isotopically similar to Superior-type banded iron formations. Other magniferous magnite + calcite bodies occur at approximately the same stratigraphic position as far 50 km from the zinc deposits. A model is presented in which the iron and zinc deposits formed along the western edge of a Middle Proterozoic marine basin. Zinc was transported by sulfate-stable brines and was precipitated under sulfate-stable conditions as zincian carbonates and Fe-Mn-Zn oxides and silicates. Whether the zincian assemblages settled from the water column or formed by replacement reactions in shallowly

Influence of the surface topography, morphology and structure on magnetic properties of ion beam sputtered iron layers, Fe/Cr/Fe- and Fe/MgO/Fe multilayers; Untersuchung der Morphologie und magnetische Eigenschaften von ionenstrahl-gesputterten Eisen-Einzelschichten, Fe/Cr/Fe- und Fe/MgO/Fe-Schichtsystemen

Energy Technology Data Exchange (ETDEWEB)

Steeb, Alexandra

2007-04-05

In this PhD Thesis, the influence of the surface topography, morphology and structure on magnetic properties of ion beam sputtered iron layers on GaAs is examined. To analyze the structure of the produced iron films, low energy electron diffraction and scanning tunneling microscopy is employed. The utilized methods to investigate the magnetic properties are Kerr- and SQUID-magnetometry and ferromagnetic resonance. It is demonstrated that on untreated as well as on presputtered and heated GaAs substrates the sputtered iron films grow epitaxially. The least surface roughness of 1 A exhibit iron films grown on untreated GaAs, while iron films on heated GaAs have the highest roughness of 30 A. The largest crystal anisotropy constant is found for the presputtered GaAs/Fe-System. For this preparation method, two monolayers of iron are determined to be magnetically dead layers. At a film thickness of 100 A, 83% of the value for saturation magnetization of bulk iron are achieved. The small observed FMR-linewidths confirm the good bulk properties of the ion beam sputtered iron. Furthermore, an antiferromagnetic interlayer exchange coupling in sputtered Fe/Cr/Fe-films was achieved. For a thickness of 12 to 17 A of the chrome interlayer, a coupling strength up to 0.2 mJ/m{sup 2} is found. To account for the small coupling strength, a strong intermixing at the interface is assumed. Finally, epitaxial Fe/MgO/Fe/FeMn multilayers are deposited on GaAs. After the structuring, it is possible to detect tunneling processes in the tunneling contacts with current-voltage measurements. The tunnel magneto resistance values of 2% are small, which can be explained by the absence of sharp, well-defined interfaces between the Fe/FeMn and the Fe/MgO interfaces. These results demonstrate, that analog to MBE the ion beam sputtering method realizes good magnetic bulk properties. However, interface sensitive phenomena are weakened because of a strong intermixing at the interfaces. (orig.)

Microbial Reducibility of Fe(III Phases Associated with the Genesis of Iron Ore Caves in the Iron Quadrangle, Minas Gerais, Brazil

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Ceth W. Parker

2013-11-01

Full Text Available The iron mining regions of Brazil contain thousands of “iron ore caves” (IOCs that form within Fe(III-rich deposits. The mechanisms by which these IOCs form remain unclear, but the reductive dissolution of Fe(III (hydroxides by Fe(III reducing bacteria (FeRB could provide a microbiological mechanism for their formation. We evaluated the susceptibility of Fe(III deposits associated with these caves to reduction by the FeRB Shewanella oneidensis MR-1 to test this hypothesis. Canga, an Fe(III-rich duricrust, contained poorly crystalline Fe(III phases that were more susceptible to reduction than the Fe(III (predominantly hematite associated with banded iron formation (BIF, iron ore, and mine spoil. In all cases, the addition of a humic acid analogue enhanced Fe(III reduction, presumably by shuttling electrons from S. oneidensis to Fe(III phases. The particle size and quartz-Si content of the solids appeared to exert control on the rate and extent of Fe(III reduction by S. oneidensis, with more bioreduction of Fe(III associated with solid phases containing more quartz. Our results provide evidence that IOCs may be formed by the activities of Fe(III reducing bacteria (FeRB, and the rate of this formation is dependent on the physicochemical and mineralogical characteristics of the Fe(III phases of the surrounding rock.

Diel cycles in dissolved barium, lead, iron, vanadium, and nitrite in a stream draining a former zinc smelter site near Hegeler, Illinois

Science.gov (United States)

Kay, R.T.; Groschen, G.E.; Cygan, G.; Dupre, David H.

2011-01-01

Diel variations in the concentrations of a number of constituents have the potential to substantially affect the appropriate sampling regimen in acidic streams. Samples taken once during the course of the day cannot adequately reflect diel variations in water quality and may result in an inaccurate understanding of biogeochemical processes, ecological conditions, and of the threat posed by the water to human health and the associated wildlife. Surface water and groundwater affected by acid drainage were sampled every 60 to 90. min over a 48-hour period at a former zinc smelter known as the Hegeler Zinc Superfund Site, near Hegeler, Illinois. Diel variations related to water quality in the aquifer were not observed in groundwater. Diel variations were observed in the temperature, pH, and concentration of dissolved oxygen, nitrite, barium, iron, lead, vanadium, and possibly uranium in surface water. Temperature, dissolved oxygen, nitrite, barium, lead, and uranium generally attained maximum values during the afternoon and minimum values during the night. Iron, vanadium, and pH generally attained minimum values during the afternoon and maximum values during the night. Concentrations of dissolved oxygen were affected by the intensity of photosynthetic activity and respiration, which are dependent upon insolation. Nitrite, an intermediary in many nitrogen reactions, may have been formed by the oxidation of ammonium by dissolved oxygen and converted to other nitrogen species as part of the decomposition of organic matter. The timing of the pH cycles was distinctly different from the cycles found in Midwestern alkaline streams and likely was the result of the photoreduction of Fe3+ to Fe 2+ and variations in the intensity of precipitation of hydrous ferric oxide minerals. Diel cycles of iron and vanadium also were primarily the result of variations in the intensity of precipitation of hydrous ferric oxide minerals. The diel variation in the concentrations of lead, uranium

Synthesis and characterization of sulfate and dodecylbenzenesulfonate intercalated zinc iron layered double hydroxides by one-step coprecipitation route

Science.gov (United States)

Zhang, Hui; Wen, Xing; Wang, Yingxia

2007-05-01

Inorganic sulfate- and organic dodecylbenzenesulfonate (DBS)-intercalated zinc-iron layered double hydroxides (LDHs) materials were prepared by one-step coprecipitation method from a mixed salt solutions containing Zn(II), Fe(II) and Fe(III) salts. The as-prepared samples have been characterized by X-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), low-temperature nitrogen adsorption, scanning electron microscopy (SEM), inductively coupled plasma emission spectroscopy (ICP), and Mössbauer spectroscopy (MS). The XRD analyses demonstrate the typical LDH-like layered structural characteristics of both products. The room temperature MS results reveal the characteristics of both the Fe(II) and Fe(III) species for SO 42--containing product, while only the Fe(III) characteristic for DBS-containing one. The combination characterization results and Rietveld analysis illustrate that the SO 42--containing product possesses the Green Rust two (GR2)-like crystal structure with an approximate chemical composition of [Zn 0.435·Fe II0.094·Fe III0.470·(OH) 2]·(SO 42-) 0.235·1.0H 2O, while the DBS-containing one exhibits the common LDH compound-like structure. The contact angle measurement indicates the evident hydrophobic properties of DBS-containing nanocomposite, compared with SO 42--containing product, due to the modification of the internal and external surface of LDHs by the organic hydrophobic chain of DBS.

Multimicronutrient Slow-Release Fertilizer of Zinc, Iron, Manganese, and Copper

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Siladitya Bandyopadhyay

2014-01-01

Full Text Available The process for the production of a slow-release micronutrient fertilizer is described. The compound contains zinc, iron, manganese, and copper as micronutrients and is produced by polymerizing a system containing phosphoric acid, zinc oxide, hematite, pyrolusite, copper sulfate, and magnesium oxide followed by neutralization of the polyphosphate chain with ammonium hydroxide. Changes in temperature, density, and viscosity of the reaction system during polymerization were studied. Reaction kinetics was studied at three different temperatures. Rate curves revealed a multistage process with essentially linear rates at each stage. Thus, each stage displayed zero order kinetics. The product was crystalline and revealed ordering of P-O-P chains. It had low solubility in water but high solubility in 0.33 M citric acid and 0.005 M DTPA. Three different field trials showed significant yield increments using the slow-release micronutrient fertilizer compared to the conventional micronutrients. Yield increments in rice were in the range of 10–55% over control (with no micronutrient and up to 17% over the conventional micronutrient fertilizers. There were significant increases in total uptake of zinc, iron, and manganese in the grain. Slow-release fertilizers also produced significant yield increases in potato as well as significant increase in vitamin C content of the tuber.

A study on the formation of iron aluminide (FeAl) from elemental powders

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Sina, H.; Corneliusson, J.; Turba, K.; Iyengar, S.

2015-07-05

Highlights: • Fe–40 at.% Al discs with coarse iron powder showed precombustion and combustion peaks. • Loose powder mixtures and discs with fine iron powder showed only combustion peaks. • Slower heating rate and fine aluminum particles promote precombustion. • The major product formed during both the reactions was Fe{sub 2}Al{sub 5}. • Heating the samples to 1000 °C yielded a stable FeAl phase as the final product. - Abstract: The formation of iron aluminide (FeAl) during the heating of Fe–40 at.% Al powder mixture has been studied using a differential scanning calorimeter. The effect of particle size of the reactants, compaction of the powder mixtures as well as the heating rate on combustion behavior has been investigated. On heating compacted discs containing relatively coarser iron powder, DSC data show two consecutive exothermic peaks corresponding to precombustion and combustion reactions. The product formed during both these reactions is Fe{sub 2}Al{sub 5} and there is a volume expansion in the sample. The precombustion reaction could be improved by a slower heating rate as well as a better surface coverage of iron particles using relatively finer aluminum powder. The combustion reaction was observed to be weaker after a strong precombustion stage. Heating the samples to 1000 °C resulted in the formation of a single and stable FeAl phase through the diffusional reaction between Fe{sub 2}Al{sub 5} and residual iron. DSC results for compacted discs containing relatively finer iron powder and for the non-compacted samples showed a single combustion exotherm during heating, with Fe{sub 2}Al{sub 5} as the product and traces of FeAl. X-ray diffraction and EDS data confirmed the formation of FeAl as the final product after heating these samples to 1000 °C.

ENVIRONMENTAL IMPACT OF THE STORED DUST-LIKE ZINC AND IRON CONTAINING WASTES

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Tatyana A. Lytaeva

2017-05-01

On the basis of laboratory research and field observations of the environmental components in the impact area of the storage of dust-like zinc and iron containing wastes, the article describes regularities of formation of hydrogeochemical halos of contamination by heavy metals and iron. Results include also the description of changes in physico-chemical groundwater composition under the storage area.

Efeito da suplementação com ferro na biodisponibilidade de zinco em uma dieta regional do nordeste do Brasil Effects of supplementation with iron on the bioavailability of zinc in the regional diet of northeastern Brazil

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Lúcia F. C. Pedrosa

1993-08-01

Full Text Available Foram investigados os efeitos da suplementação com ferro na biodisponibilidade de zinco de uma dieta "regional" do Nordeste (DRNE, em ratos albinos Wistar, consumindo rações à base da referida dieta (DRNE e rações controle. As rações DRNE, continham 16 mg de Zn/kg e níveis de 35 mg, 70 mg e 140mg Fe/kg. As rações controle foram elaboradas segundo o "Committee on Laboratory Animal Diets", contendo níveis de proteína, ferro e zinco ajustados aos das rações experimentais DRNE. Os parâmetros utilizados para medir a biodisponibilidade do zinco foram: Índice de Absorção Aparente do Zn e nível total de Zn nos fêmures. Os resultados obtidos demonstraram que a suplementação com ferro diminuiu a biodisponibilidade do Zn, e os efeitos dessa interferência foram influenciados pela qualidade da dieta e pelas proporções Fe:Zn. Tal fato deve ser considerado nas práticas que envolvem fortificação de alimentos e/ou suplementos medicamentosos, comuns nas populações com carências nutricionais.The effects of supplementation with iron on the zinc bioavailability of the regional diet of northeastern Brazil (RDN, were investigated. One assay with Wistar rats, feed on RDN and control diets was carried out. The RDN diets contained 16 mg Zn/kg and levels of 35 mg, 70 mg and 140 mg Fe/kg, respectively. The control diets were prepared according to the standards of the Committee on Laboratory Animal Diets, with levels of protein, iron and zinc identical to those of RDN diets. Index of apparent absorption and zinc retained in the femur of the animals were the parameters utilized to measure zinc bioavailability. The results demonstrated that the supplementation with iron decreased the zinc bioavailability, and the effects were seen to affect diet quality and the Fe:Zn ratio. This fact must be taken into consideration in practices such as the fortying of foodstuffs and the administration of vitamin-mineral supplements to populations with

Effect of different home-cooking methods on the bioaccessibility of zinc and iron in conventionally bred cowpea (Vigna unguiculata L. Walp consumed in Brazil

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Elenilda J. Pereira

2016-03-01

Full Text Available Background: The cowpea (Vigna unguiculata L. Wap. is an excellent source of iron and zinc. However, iron from plant sources is poorly absorbed compared with iron from animal sources. Objectives: The objective of this study was to evaluate iron and zinc bioaccessibility in cowpea cultivars after processing. Methods: Zinc and iron bioaccessibilities in cowpea samples were determined based on an in vitro method involving simulated gastrointestinal digestion with suitable modifications. Results: When water-soaked beans were cooked in a regular pan, the highest percentage of bioaccessible iron obtained was 8.92%, whereas when they were cooked in a pressure cooker without previous soaking, the highest percentage was 44.33%. Also, the percentage of bioaccessible zinc was 52.78% when they were cooked in a regular pan without prior soaking. Higher percentages of bioaccessible iron were found when cooking was done in a pressure cooker compared with regular pan cooking. In all cultivars, cooking of cowpea beans in both pressure cooker and in a regular pan yielded higher percentages of bioaccessible zinc compared with availability of bioaccessible iron. Conclusions: Iron bioaccessibility values suggest that cooking in a regular pan did not have a good effect on iron availability, since the percentage of bioaccessible iron was lower than that of zinc. The determination of iron and zinc bioaccessibility makes it possible to find out the actual percentage of absorption of such minerals and allows the development of efficient strategies for low-income groups to access foods with high levels of these micronutrients.

Sonochemically synthesized iron-doped zinc oxide nanoparticles: Influence of precursor composition on characteristics

International Nuclear Information System (INIS)

Roy, Anirban; Maitra, Saikat; Ghosh, Sobhan; Chakrabarti, Sampa

2016-01-01

Highlights: • Sonochemical synthesis of iron-doped zinc oxide nanoparticles. • Green synthesis without alkali at room temperature. • Characterization by UV–vis spectroscopy, FESEM, XRD and EDX. • Influence of precursor composition on characteristics. • Composition and characteristics are correlated. - Abstract: Iron-doped zinc oxide nanoparticles have been synthesized sonochemically from aqueous acetyl acetonate precursors of different proportions. Synthesized nanoparticles were characterized with UV–vis spectroscopy, X-ray diffraction and microscopy. Influences of precursor mixture on the characteristics have been examined and modeled. Linear correlations have been proposed between dopant dosing, extent of doping and band gap energy. Experimental data corroborated with the proposed models.

The shaping of zinc coating on surface steels and ductile iron casting

Directory of Open Access Journals (Sweden)

D. Kopyciński

2010-01-01

Full Text Available The studies aimed at an analysis of the formation and growth kinetics of zinc coating on reactive silicon-killed steels in a zinc bath. The growth kinetics of the produced zinc coatings was evaluated basing on the power-law growth equation. As regards galvanizing of the surface of products, investigation was done for various steel grades and ductile iron (DI taking into account the quality and thickness of coating. It has been proved that the chemical constitution of basis significantly influences the kinetics of growth of the individual phases in a zinc coating. This relationship was evaluated basing on the, so called, silicon and phosphorus equivalent ESi,P and coating thickness dependences were obtained.

Zinc recovery from iron and steel making wastes by conventional and microwave assisted leaching

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Ján Vereš

2011-12-01

Full Text Available Significant quantities of sludge and dust are generated as a waste material or byproduct every day from iron and steel industries.Nowadays The occurrence and recovery of metallurgical wastes from steelmaking and iron making processes is a great problem, mainlydue to the big amount and environmental pollution of these wastes by heavy metals. The future technology of fine-grain metallurgicalwastes treatment is mainly the thing of ecological and financial limits. This work explains the removal of zinc from blast furnace sludgeby hydrometallurgical process. The aim of this work was to carry out a chemical, physical, structural, and morphologicalcharacterization of these waste materials and subsequently to find out the best suitable method for the hydrometallurgical treatment.The experimental work includes full plant experiments. Extraction conditions such as the effect of microwave power, leaching agent,acid concentration, S/L ratio and extraction time on the zinc removal efficiency were evaluated. The main goal is to set the bestconditions to transfer zinc into the solution while the iron should to remain in the solid phase.

Characterisation and application of the Fe(II)/Fe(III) redox reaction in an ionic liquid analogue

International Nuclear Information System (INIS)

Lloyd, David; Vainikka, Tuomas; Ronkainen, Markus; Kontturi, Kyösti

2013-01-01

Highlights: • The Fe(II)/Fe(III) reaction is shown to be facile using a wall-jet electrode and RDE. • Deposition/stripping of iron has equally slow kinetics as in aqueous systems. • An IL based all-iron RFB is reported for the first time, energy efficiency is 37%. • An Zn–Fe complex is shown to form. In an RFB this gives an energy efficiency of 78%. • Problems resulting from the use of redox probes and urea-based DES are demonstrated. -- Abstract: In this paper we report the properties of the Fe(II)/Fe(III) reaction in a deep eutectic solvent based on choline chloride and ethylene glycol. This reaction is shown to be facile using a wall-jet electrode and rotating disc electrode. The deposition and stripping of iron exhibits equally slow kinetics as in aqueous systems. Using these two reactions an all-iron redox flow battery based on ionic liquids is reported for the first time. An energy efficiency of 37% is attained at a current density of 0.5 mA cm −2 . A Zn(II)–Fe(II) complex is shown to form when zinc is oxidized by Fe(III). When this complex is applied in a redox flow battery energy efficiencies of 78% are achieved at a current density of 0.5 mA cm −2

Iron Isotopic Compositions of Troilite (FeS) Inclusions from Iron Meteorites

Energy Technology Data Exchange (ETDEWEB)

Cook, David L.; Schönbächler, Maria, E-mail: david.cook@erdw.ethz.ch [Institut für Geochemie und Petrologie, ETH Zürich, Clausiusstrasse 25, 8092 Zürich (Switzerland)

2017-10-01

We report non-mass-dependent Fe isotopic data for troilite (FeS) inclusions from 10 iron meteorites, representing both non-magmatic (IAB) and magmatic groups (IIAB, IIIAB, IVA). No resolvable variations are present in the most neutron-rich isotope ({sup 58}Fe), but small deficits (≈−0.1 ε ) in {sup 56}Fe were observed in several inclusions. With the exception of several Ca–Al-rich inclusions in primitive meteorites, these are the first reported non-mass-dependent variations in Fe isotopes for material formed in the early solar system. Nucleosynthetic variations in Ni isotopes were previously reported in these same samples. The effects in Fe isotopes are not correlated with those in Ni, which suggests that the origins of the isotopic variations are decoupled from one another. The {sup 56}Fe deficits may represent incomplete mixing of the precursor dust in the protoplanetary disk. Alternatively, a parent body process (e.g., irradiation by galactic cosmic rays) may have modified the Fe isotopic compositions of some inclusions, which initially had homogeneous Fe isotopic compositions.

A complementary and synergistic effect of Fe-Zn binary metal oxide in the process of high-temperature fuel gas desulfurization

Institute of Scientific and Technical Information of China (English)

翁斯灏; 吴幼青

1996-01-01

57Fe Mossbauer spectroscopy was used to investigate the evolution of Fe-Zn binary metal oxide sorbent in the process of high-temperature fuel gas desulfurization. The results of phase analyses show that Fe-Zn binary metal oxide sorbent is rapidly reduced in hot fuel gas and decomposed to new phases of highly dispersed microcrystalline elemental iron and zinc oxide, both of which become the active desulfurization constituents. A complementary and synergistic effect between active iron acting as a high sulfur capacity constituent and active zinc oxide acting as a deep refining desulfurization constituent exists in this type of sorbent for hot fuel gas desulfurization.

Anemia and iron, zinc, copper and magnesium deficiency in Mexican adolescents: National Health and Nutrition Survey 2006.

Science.gov (United States)

De la Cruz-Góngora, Vanessa; Gaona, Berenice; Villalpando, Salvador; Shamah-Levy, Teresa; Robledo, Ricardo

2012-01-01

To describe the frequency of anemia and iron, zinc, copper and magnesium deficiencies among Mexican adolescents in the probabilistic survey ENSANUT 2006. The sample included 2447 adolescents aged 12 to 19 y. Capillary hemoglobin and venous blood samples were collected to measure the concentrations of ferritin, sTFR, CRP, zinc, iron, copper and magnesium. Logistic regression models were constructed to assess the risk for mineral deficiencies. The overall prevalence of anemia was 11.8 and 4.6%, body iron deficiency 18.2 and 7.9% for females and males, respectively. Overall prevalence of tissue iron deficiency was 6.9%, low serum copper were 14.4 and 12.25%; zinc 28.4 and 24.5%, magnesium 40 and 35.3%; for females and males, respectively. There is a high prevalence of mineral deficiency in Mexican adolescents; females were more prone to have more mineral deficiencies. Nutritional interventions are necessaries in order to reduce and control them.

Acceptability and solubility of iron and zinc contents of modified Moringa oleifera sauces consumed in the Far-north region of Cameroon.

Science.gov (United States)

Mawouma, Saliou; Ponka, Roger; Mbofung, Carl Moses

2017-03-01

Consumption of Moringa oleifera leaves is a local and inexpensive solution to iron and zinc deficiencies in the Far-north region of Cameroon. However, traditional household's cooking techniques result in sauces with high pH levels and low leaves incorporation rates that compromise the bioavailability of iron and zinc. The aim of our study was to investigate the effect of modifying a standard Moringa sauce on consumer acceptability and the solubility of iron and zinc, which is an indicator of their bioavailability. Lime juice or tamarind pulp was added to a standard recipe in order to reduce the pH by about one unit, and Moringa leaf powder was incorporated in each acidulated sauce at three levels (1, 2, and 4 g/100 g of sauce). All the formulations were evaluated for their acceptability by 30 housewives using a five-point hedonic scale. The pH was measured by a digital electronic pH-meter. Moisture and ash were determined by AOAC methods. Total iron and zinc contents were determined by atomic absorption spectrophotometry, and soluble iron and zinc by HCl-extractability. The lime juice-acidulated sauce and the tamarind pulp-acidulated sauce enriched with 1 g of Moringa leaf powder were the most acceptable formulations with scores of 3.4 and 3.6, respectively. Their chemical analysis showed a reduced pH (6.4 and 6.1, respectively), compared to the Control (7.2). Lime juice-acidulated sauce improved iron and zinc solubility from 42.19 to 66.38% and 54.03 to 82.03%, respectively. Tamarind pulp-acidulated sauce enriched with 1 g of Moringa leaf powder showed a decrease in iron solubility from 42.19 to 38.26% and an increase in zinc solubility from 54.03 to 72.86%. These results confirm the beneficial effect of lime juice in improving iron and zinc bioavailability.

Preparation of magnetic and bioactive calcium zinc iron silicon oxide composite for hyperthermia treatment of bone cancer and repair of bone defects.

Science.gov (United States)

Jiang, Yumin; Ou, Jun; Zhang, Zhanhe; Qin, Qing-Hua

2011-03-01

In this paper, a calcium zinc iron silicon oxide composite (CZIS) was prepared using the sol-gel method. X-ray diffraction (XRD) was then employed to test the CZIS composite. The results from the test showed that the CZIS had three prominent crystalline phases: Ca(2)Fe(1.7)Zn(0.15)Si(0.15)O(5), Ca(2)SiO(4), and ZnFe(2)O(4). Calorimetric measurements were then performed using a magnetic induction furnace. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) analysis were conducted to confirm the growth of a precipitated hydroxyapatite phase after immersion in simulated body fluid (SBF). Cell culture experiments were also carried out, showing that the CZIS composite more visibly promoted osteoblast proliferation than ZnFe(2)O(4) glass ceramic and HA, and osteoblasts adhered and spread well on the surfaces of composite samples.

Role of a gas phase in the kinetics of zinc and iron reduction with carbon from slag melts

Science.gov (United States)

Chumarev, V. M.; Selivanov, E. N.

2013-03-01

The influence of the mass transfer conditions in the gas phase having formed at the carbon-slag melt interface on CO regeneration is approximately estimated in the framework of a two-stage scheme of metal reduction from slag melts by carbon. The effect of zinc vapors on the combined reduction of iron and zinc from slags is considered. The influence of the slag composition and temperature on the critical concentration of zinc oxide above which no iron forms as an individual phase is explained.

The Effect of Ductile Cast Iron Matrix on Zinc Coating During Hot Dip Galvanising of Castings

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D. Kopyciński

2012-12-01

Full Text Available The growth kinetics of the zinc coating formed on the surface of casting made from ductile iron grade EN-GJS-500-3 was investigated. To produce homogenous metal matrix in test samples, the normalising and ferritising annealing was carried out. Studies showeda heterogeneous structure of cast iron with varying content of the phases formed. This was followed by hot dip galvanising treatment at450°C to capture the growth kinetics of the zinc coating (the time of the treatment ranged from 60 to 600 seconds. Nonlinear estimation of the determined growth kinetics of the alloyed layer of a zinc coating was made and an equation of the zinc coating growth was derived.Based on the results of the investigations it was concluded that thickness of the zinc coating formed on the surface of casting with a 100% pearlitic matrix makes 55% of the thickness of coating formed on the surface in 100% ferritic.

The Effect of Ductile Cast Iron Matrix on Zinc Coating During Hot Dip Galvanising of Castings

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Kopyciński D.

2012-12-01

Full Text Available The growth kinetics of the zinc coating formed on the surface of casting made from ductile iron grade EN-GJS-500-3 was investigated. To produce homogenous metal matrix in test samples, the normalising and ferritising annealing was carried out. Studies showed a heterogeneous structure of cast iron with varying content of the phases formed. This was followed by hot dip galvanising treatment at 450°C to capture the growth kinetics of the zinc coating (the time of the treatment ranged from 60 to 600 seconds. Nonlinear estimation of the determined growth kinetics of the alloyed layer of a zinc coating was made and an equation of the zinc coating growth was derived. Based on the results of the investigations it was concluded that thickness of the zinc coating formed on the surface of casting with a 100% pearlitic matrix makes 55% of the thickness of coating formed on the surface in 100% ferritic.

Isotope aided studies on the bioavailability of iron and zinc from human diets

International Nuclear Information System (INIS)

Raghuramulu, N.

1992-01-01

Iron deficiency anaemia is a major public health problem in many developing countries including India. Recent multicentric studies indicated that in rural population of India, 60% of preschool children and 40-60 % of women of child bearing age may suffer from anaemia. Studies by Sood et al indicated that iron stores are generally lower in the population as compared to populations in other countries. It is therefore possible that prelatent iron deficiency may be even higher who look otherwise healthy and adequately nourished. Iron absorption from habitual diets of Indians has been determined in the past by the chemical balance methods. Iron absorption determined by this method may be a gross over estimate. A more reliable estimate of iron absorption from composite meals can be obtained by the radio isotopic methods in which foods are extrinsically or intrinsically tagged with radio iron ( 55 Fe or 59 Fe). Using these methods iron absorption from a few habitual diets was studied. 15 refs

Micronutrient (provitamin A and iron/zinc) retention in biofortified crops

African Journals Online (AJOL)

Degradation also occurs during the storage of dried products (e.g. from sweet potato, maize, cassava) at ambient temperature, and a short shelf life is a constraint that should be considered when foods are biofortified for provitamin A. Iron and zinc retention were high for common beans (Phaseolus vulgaris) and cowpeas ...

The use of radioisotopes and low abundance stable isotopes for the study of bioavailability and the metabolism of iron, zinc and copper

International Nuclear Information System (INIS)

Aggett, P.J.; Fairweather Tait, S.

1994-01-01

The use of whole body counting and imaging with ''area of interest'' counting to monitor the metabolism of zinc in healthy volunteers and patients with coeliac diseases and cirrhosis is described as are studies of interaction between iron and copper. Stable isotopes of iron, copper and zinc have been used to investigate the metabolism of these elements in young infants and have proved useful in assessing the validity of current estimated requirements particularly of iron. Stable isotopes have also been used to improve the classic metabolic balance approach to the study of the homeostasis of zinc in zinc deprived volunteers, and have progressed to studies using plasma kinetic curves of the systemic compartmentation of zinc

Interaction genotype by season and its influence on the identification of beans with high content of zinc and iron

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Camila Andrade Silva

2012-01-01

Full Text Available The mineral contents in common bean seeds are influenced, in addition to genetic variation, by environmental crop conditions, especially by the soil type and chemical composition and by the genotype x environment interaction. This study was carried out to verify if the zinc and iron contents are affected by the crop growing period. Ten lines with high iron and zinc contents and ten with low contents were assessed in three seasons: "wet season" of 2009/2010 (sowing in November; "dry season" of 2010 (sowing in February and "winter season" of 2010 (sowing in July, in Lavras, Minas Gerais State, Brazil. The experimental design used was randomized blocks with three replications and plots consisting of two rows of two meters, with a spacing of 0.50 m. The seeds harvested were assessed in regard to iron and zinc mineral contents. The greatest contents were observed in the winter season and the smallest ones in the dry season, with sowing in February. It was observed that in the mean of the three harvests, the lines classified as having high iron and zinc content exhibited an iron quantity 11.0% and a zinc quantity 6.8% above those of low content. The lines by seasons interaction occurs. However, its interference in identification of the groups with high and low content of the two nutrients is not great.

Diffusion of iron in β-iron telluride (Fe1.12Te) by Moessbauer spectroscopy and tracer method

International Nuclear Information System (INIS)

Magara, Masaaki; Tsuji, Toshihide; Naito, Keiji

1993-01-01

The diffusion coefficient of iron in a β-iron telluride (Fe 1.12 Te) polycrystalline sample was measured by Moessbauer diffusional line broadening method which relates to the collapse of coherence in gamma-ray photon by the atomic jump at local sites. The diffusion coefficient of iron along the c-axis in nearly single crystal of β-iron telluride was also measured by tracer technique which shows the results of an atom transport in long distance. The activation energies for the diffusion of iron in Fe 1.12 Te obtained by the Moessbauer spectroscopy and the tracer method were 91.5±5.4 and 106±23 kJ/mol, respectively. The diffusion coefficients of iron in β-iron telluride obtained by Moessbauer line broadening are in fair agreement with the values averaged from that along c-axis obtained by tracer method and that along a- and b-axes obtained from reaction rate constant between iron and tellurium by the previous study of the present authors. (orig.)

Clean hydrometallurgical route to recover zinc, silver, lead, copper, cadmium and iron from hazardous jarosite residues produced during zinc hydrometallurgy

International Nuclear Information System (INIS)

Ju Shaohua; Zhang Yifei; Zhang Yi; Xue Peiyi; Wang Yihui

2011-01-01

Highlights: → The extraction fractions of various valuable metals during NH 4 Cl leaching are very high. The sintered residue was leached in 6 mol L -1 aqueous NH 4 Cl solution at 105 o C, followed by filtration. The leaching extraction of Zn, Pb, Cu, Cd and Ag are more than 95%. → The process can detoxified the hazardous elements such as Pb, As, Cd thoroughly. Then the NH 4 Cl leaching residue were leached again in 30 wt% aqueous NaOH solution for 1 h at 160 o C, and about 94% of As and 73% of Si were removed from the residue. → The final residue contains about 55 wt% Fe, and have the potential to be used as iron concentrate. - Abstract: A hydrometallurgical process for treating the hazardous jarosite residue from zinc hydrometallurgy was proposed, for not only detoxifying the residue, but also recovering the contained valuable metal components. The jarosite was initially activated and decomposed by sintering at 650 o C for 1 h. The sintered residue was leached in 6 mol L -1 aqueous NH 4 Cl solution at 105 o C, followed by filtration. The leaching extraction of Zn, Pb, Cu, Cd and Ag are more than 95%. During reduction with Zn powder, more than 93% of Pb, Cu, Ag and Cd can be simultaneously recovered. Then the NH 4 Cl leaching residue were leached again in 30 wt% aqueous NaOH solution for 1 h at 160 o C, and about 94% of As and 73% of Si were removed from the residue. The final residue was almost completely detoxified, and contains about 55 wt% Fe, which can be used as an iron concentration.

Magnetic characteristics of ultrafine Fe particles reduced from uniform iron oxide particles

Science.gov (United States)

Bridger, K.; Watts, J.; Tadros, M.; Xiao, Gang; Liou, S. H.; Chien, C. L.

1987-04-01

Uniform, cubic 0.05-μm iron oxide particles were formed by forced hydrolysis of ferric perchlorate. These particles were reduced to α-Fe by heating in hydrogen at temperatures between 300 and 500 °C. The effect of reduction temperature and various prereduction treatments on the microstructure of the iron particles will be discussed. Complete reduction to α-Fe was established by 57Fe Mössbauer spectroscopy and x-ray diffraction. Magnetic measurements on epoxy and polyurethane films containing these particles with various mass fractions gave coercivities as high as 1000 Oe. The relationship between the magnetic measurements and the microstructure will be discussed. Na2SiO3 is found to be the best coating material for the process of reducing iron oxide particles to iron.

Iron and zinc deficiencies in China: existing problems and possible solutions

NARCIS (Netherlands)

Guansheng Ma,

2007-01-01

Micronutrient deficiencies affect the health and development of the population of China as well as its socia] and economic development. Iron and zinc deficiencies are quite prevalent, while insufficient intake and poor bioavailability are the major causes. Phytate is be!ieved to bc a potent

Potentiometric and electrokinetic signatures of iron(II) interactions with (α,γ)-Fe2O3.

Science.gov (United States)

Toczydłowska, Diana; Kędra-Królik, Karolina; Nejbert, Krzysztof; Preočanin, Tajana; Rosso, Kevin M; Zarzycki, Piotr

2015-10-21

The electrochemical signatures of Fe(II) interactions with iron(III) oxides are poorly understood, despite their importance in controlling the amount of mobilized iron. Here, we report the potentiometric titration of α,γ-Fe2O3 oxides exposed to Fe(II) ions. We monitored in situ surface and ζ potentials, the ratio of mobilized ferric to ferrous, and the periodically analyzed nanoparticle crystal structure using X-ray diffraction. Electrokinetic potential reveals weak but still noticeable specific sorption of Fe(II) to the oxide surface under acidic conditions, and pronounced adsorption under alkaline conditions that results in a surface potential reversal. By monitoring the aqueous iron(II/III) fraction, we found that the addition of Fe(II) ions produces platinum electrode response consistent with the iron solubility-activity curve. Although, XRD analysis showed no evidence of γ-Fe2O3 transformations along the titration pathway despite iron cycling between aqueous and solid reservoirs, the magnetite formation cannot be ruled out.

Crystal structure of a sodium, zinc and iron(III-based non-stoichiometric phosphate with an alluaudite-like structure: Na1.67Zn1.67Fe1.33(PO43

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Jamal Khmiyas

2015-06-01

Full Text Available The new title compound, disodium dizinc iron(III tris(phosphate, Na1.67Zn1.67Fe1.33(PO43, which belongs to the alluaudite family, has been synthesized by solid-state reactions. In this structure, all atoms are in general positions except for four, which are located on special positions of the C2/c space group. This structure is characterized by cation substitutional disorder at two sites, one situated on the special position 4e (2 and the other on the general position 8f. The 4e site is partially occupied by Na+ [0.332 (3], whereas the 8f site is entirely filled by a mixture of Fe and Zn. The full-occupancy sodium and zinc atoms are located at the Wyckoff positions on the inversion center 4a (-1 and on the twofold rotation axis 4e, respectively. Refinement of the occupancy ratios, bond-valence analysis and the electrical neutrality requirement of the structure lead to the given composition for the title compound. The three-dimensional framework of this structure consists of kinked chains of edge-sharing octahedra stacked parallel to [10-1]. The chains are formed by a succession of trimers based on [ZnO6] octahedra and the mixed-cation FeIII/ZnII [(Fe/ZnO6] octahedra [FeIII:ZnIII ratio 0.668 (3/0.332 (3]. Continuous chains are held together by PO4 phosphate groups, forming polyhedral sheets perpendicular to [010]. The stacked sheets delimit two types of tunnels parallel to the c axis in which the sodium cations are located. Each Na+ cation is coordinated by eight O atoms. The disorder of Na in the tunnel might presage ionic mobility for this material.

Identification of Ftr1 and Zrt1 as iron and zinc micronutrient transceptors for activation of the PKA pathway in Saccharomyces cerevisiae.

Science.gov (United States)

Schothorst, Joep; Zeebroeck, Griet V; Thevelein, Johan M

2017-03-02

Multiple types of nutrient transceptors, membrane proteins that combine a transporter and receptor function, have now been established in a variety of organisms. However, so far all established transceptors utilize one of the macronutrients, glucose, amino acids, ammonium, nitrate, phosphate or sulfate, as substrate. This is also true for the Saccharomyces cerevisiae transceptors mediating activation of the PKA pathway upon re-addition of a macronutrient to glucose-repressed cells starved for that nutrient, re-establishing a fermentable growth medium. We now show that the yeast high-affinity iron transporter Ftr1 and high-affinity zinc transporter Zrt1 function as transceptors for the micronutrients iron and zinc . We show that replenishment of iron to iron-starved cells or zinc to zinc-starved cells triggers within 1-2 minutes a rapid surge in trehalase activity, a well-established PKA target. The activation with iron is dependent on Ftr1 and with zinc on Zrt1, and we show that it is independent of intracellular iron and zinc levels. Similar to the transceptors for macronutrients, Ftr1 and Zrt1 are strongly induced upon iron and zinc starvation, respectively, and they are rapidly downregulated by substrate-induced endocytosis. Our results suggest that transceptor-mediated signaling to the PKA pathway may occur in all cases where glucose-repressed yeast cells have been starved first for an essential nutrient, causing arrest of growth and low activity of the PKA pathway, and subsequently replenished with the lacking nutrient to re-establish a fermentable growth medium. The broadness of the phenomenon also makes it likely that nutrient transceptors use a common mechanism for signaling to the PKA pathway.

Identification of Ftr1 and Zrt1 as iron and zinc micronutrient transceptors for activation of the PKA pathway in Saccharomyces cerevisiae

Directory of Open Access Journals (Sweden)

Joep Schothort

2017-03-01

Full Text Available Multiple types of nutrient transceptors, membrane proteins that combine a transporter and receptor function, have now been established in a variety of organisms. However, so far all established transceptors utilize one of the macronutrients, glucose, amino acids, ammonium, nitrate, phosphate or sulfate, as substrate. This is also true for the Saccharomyces cerevisiae transceptors mediating activation of the PKA pathway upon re-addition of a macronutrient to glucose-repressed cells starved for that nutrient, re-establishing a fermentable growth medium. We now show that the yeast high-affinity iron transporter Ftr1 and high-affinity zinc transporter Zrt1 function as transceptors for the micronutrients iron and zinc. We show that replenishment of iron to iron-starved cells or zinc to zinc-starved cells triggers within 1-2 minutes a rapid surge in trehalase activity, a well-established PKA target. The activation with iron is dependent on Ftr1 and with zinc on Zrt1, and we show that it is independent of intracellular iron and zinc levels. Similar to the transceptors for macronutrients, Ftr1 and Zrt1 are strongly induced upon iron and zinc starvation, respectively, and they are rapidly downregulated by substrate-induced endocytosis. Our results suggest that transceptor-mediated signaling to the PKA pathway may occur in all cases where glucose-repressed yeast cells have been starved first for an essential nutrient, causing arrest of growth and low activity of the PKA pathway, and subsequently replenished with the lacking nutrient to re-establish a fermentable growth medium. The broadness of the phenomenon also makes it likely that nutrient transceptors use a common mechanism for signaling to the PKA pathway.

Correlations in distribution and concentration of calcium, copper and iron with zinc in isolated extracellular deposits associated with age-related macular degeneration

Science.gov (United States)

Flinn, Jane M; Kakalec, Peter; Tappero, Ryan; Jones, Blair F.; Lengyel, Imre

2014-01-01

Zinc (Zn) is abundantly enriched in sub-retinal pigment epithelial (RPE) deposits, the hallmarks of age-related macular degeneration (AMD), and is thought to play a role in the formation of these deposits. However, it is not known whether Zn is the only metal relevant for sub-RPE deposit formation. Because of their involvement in the pathogenesis of AMD, we determined the concentration and distribution of calcium (Ca), iron (Fe) and copper (Cu) and compared these with Zn in isolated and sectioned macular (MSD), equatorial (PHD) and far peripheral (FPD) sub-RPE deposits from an 86 year old donor eye with post mortem diagnosis of early AMD. The sections were mounted on Zn free microscopy slides and analyzed by microprobe synchrotron X-ray fluorescence (μSXRF). Metal concentrations were determined using spiked sectioned sheep brain matrix standards, prepared the same way as the samples. The heterogeneity of metal distributions was examined using pixel by pixel comparison. The orders of metal concentrations were Ca ⋙ Zn > Fe in all three types of deposits but Cu levels were not distinguishable from background values. Zinc and Ca were consistently present in all deposits but reached highest concentration in MSD. Iron was present in some but not all deposits and was especially enriched in FPD. Correlation analysis indicated considerable variation in metal distribution within and between sub-RPE deposits. The results suggest that Zn and Ca are the most likely contributors to deposit formation especially in MSD, the characteristic risk factor for the development of AMD in the human eye.

[Tolerability of iron preparation Actiferol Fe® in children treated for iron deficiency anemia].

Science.gov (United States)

Jackowska, Teresa; Sapała-Smoczyńska, Alicja; Kamińska, Ewa

2015-01-01

Iron de„ciency anemia is the most frequently occurring anemia during the childhood period. Supplementation with adequate doses of iron remains a basic method of prevention and treatment. The various available products containing iron are characterized by a different degree of patient tolerability. Actiferol Fe® is a micronized, dispersible ferric pyrophosphate which improves its water solubility, and therefore it has better absorption and bioavailability. The assessment of tolerability of Actiferol Fe® in children who were administered this product to treat or prevent of iron de„ciency anemia. The methods of administration and the incidence of adverse effects were analyzed. Eighty children (64 boys and 16 girls) aged from one month to 6 years who met the criteria of an indication to be treated with iron were included into the study. The assessment of selected parameters was based on the questionnaire which included questions about tolerability, method of administration, convenience of usage and adverse e#ects. The questionnaire was „lled in by parents (usually by the mother). The study indicated that Actiferol Fe® has very good or good tolerability in 87.5% (70/80) of patients - 46.3% (37/80) and 41.2% (33/80), respectively. The most frequent method of administration was in liquid form after dissolving: in water - 31,3% (25/80), in orange juice - 18.8% (15/80) or in milk formulas - in 17.5% (14/80) of patients. The method of administration was assessed as convenient or very convenient by 84% (67/80) of participants. Out of the adverse effects reported, the most frequent were change in the stool consistency into harder, abdominal pain and constipation - in 20% (16/80), 11.25% (9/80), 10% (8/80) cases, respectively. Diarrhea, pain during defecation occurred occasionally. A dark color of the stool was reported by 55% (44/80) of patients. In only one case (1.25%) the parents resigned from the product administration and replaced it with another iron product (no

Effects of mine drainage on the River Hayle, Cornwall. Factors affecting concentrations of copper, zinc, and iron in water, sediments and dominant invertebrate fauna

Energy Technology Data Exchange (ETDEWEB)

Brown, B.E.

1977-02-15

Concentrations of copper, zinc and iron were measured in waters, sediments and invertebrates collected from the River Hayle. In river water at least 70% of copper and iron was associated with the ''particulate'' fraction whereas 80% of zinc was in the ''soluble'' form. Although total concentrations of zinc in water exceeded those of copper approximately ten fold, copper predominated over zinc in the sediments by a factor of approximately three. Iron was the most abundant metal recorded in both water and sediments. Seasonal differences in ''total'' metal content of waters suggested that concentrations of copper, zinc and iron increased during periods of high flow and decreased during lower flows. Copper concentrations in the sediment, unlike zinc and iron, showed markedly higher values during the summer sampling period when flows were minimal. In the ''free-living'' Trichoptera larvae, concentrations of copper and zinc in the tissue appeared to follow copper and zinc levels in the water. Similar relationships in Odonata and Plecoptera larvae were not obtained. Factors affecting animal/metal relationships are discussed with particular reference to adaptation shown by organisms exposed to high concentrations of heavy metals in their environment.

Effects of phytase, cellulase, and dehulling treatments on iron and zinc in vitro solubility in faba bean (Vicia faba L.) Flour and Legume Fractions.

Science.gov (United States)

Luo, Yu-Wei; Xie, Wei-Hua; Cui, Qun-Xiang

2010-02-24

Simulations of gastrointestinal digestion were used to try to identify the nature of the complexes between antinutritional factors and iron and zinc in faba bean and legume fractions. In digestible residue of raw faba bean flour, simultaneous action of cellulase and phytases made it possible to release about 28% units more iron than that released with the treatment without enzymes. About 49.8% of iron in raw faba bean flour was solubilized after in vitro digestion and simultaneous action of cellulase and phytase. In the hull fraction, the action of phytases and the simultaneous action of cellulase and phytase allowed about 7 and 35% units of additional zinc to be solubilized, respectively. Single enzymatic degradation of phytates from dehulled faba bean allowed solubilization from 65 to 93% of zinc, depending upon the treatment. In dehulled faba bean, iron was chelated by phytates and by fibers, whereas zinc was almost exclusively chelated by phytates. In the hull of faba bean, a high proportion of iron was chelated by iron-tannins, while the rest of iron as well as the majority of zinc were chelated in complexes between phytates and fibers.

Enhanced iron and zinc accumulation in genetically engineered pineapple plants using soybean ferritin gene.

Science.gov (United States)

Mhatre, Minal; Srinivas, Lingam; Ganapathi, Thumballi R

2011-12-01

Pineapple (Ananas comosus L. Merr., cv. "Queen") leaf bases were transformed with Agrobacterium tumefaciens strain EHA 105 harboring the pSF and pEFESF plasmids with soybean ferritin cDNA. Four to eight percent of the co-cultivated leaf bases produced multiple shoots 6 weeks after transfer to Murashige and Skoog's medium supplemented with α-naphthalene acetic acid 1.8 mg/l, indole-3-butyric acid 2.0 mg/l, kinetin 2.0 mg/l, cefotaxime 400 mg/l, and kanamycin 50 mg/l. Putatively transformed shoots (1-2 cm) were selected and multiplied on medium of the same composition and elongated shoots (5 cm) were rooted on liquid rooting medium supplemented with cefotaxime 400 mg/l and kanamycin 100 mg/l. The rooted plants were analyzed through PCR, genomic Southern analysis, and reverse transcription PCR. The results clearly confirmed the integration and expression of soybean ferritin gene in the transformed plants. Atomic absorption spectroscopic analysis carried out with six independently transformed lines of pSF and pEFE-SF revealed a maximum of 5.03-fold increase in iron and 2.44-fold increase in zinc accumulation in the leaves of pSF-transformed plants. In pEFE-SF-transformed plants, a 3.65-fold increase in iron and 2.05-fold increase in zinc levels was observed. Few of the transgenic plants were hardened in the greenhouse and are being grown to maturity to determine the enhanced iron and zinc accumulation in the fruits. To the best of our knowledge this is the first report on the transformation of pineapple with soybean ferritin for enhanced accumulation of iron and zinc content in the transgenic plants.

Synthesis and characterization of sulfate and dodecylbenzenesulfonate intercalated zinc-iron layered double hydroxides by one-step coprecipitation route

International Nuclear Information System (INIS)

Zhang Hui; Wen Xing; Wang Yingxia

2007-01-01

Inorganic sulfate- and organic dodecylbenzenesulfonate (DBS)-intercalated zinc-iron layered double hydroxides (LDHs) materials were prepared by one-step coprecipitation method from a mixed salt solutions containing Zn(II), Fe(II) and Fe(III) salts. The as-prepared samples have been characterized by X-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), low-temperature nitrogen adsorption, scanning electron microscopy (SEM), inductively coupled plasma emission spectroscopy (ICP), and Moessbauer spectroscopy (MS). The XRD analyses demonstrate the typical LDH-like layered structural characteristics of both products. The room temperature MS results reveal the characteristics of both the Fe(II) and Fe(III) species for SO 4 2- -containing product, while only the Fe(III) characteristic for DBS-containing one. The combination characterization results and Rietveld analysis illustrate that the SO 4 2- -containing product possesses the Green Rust two (GR2)-like crystal structure with an approximate chemical composition of [Zn 0.435 .Fe II 0.094 .Fe III 0.470 .(OH) 2 ].(SO 4 2- ) 0.235 .1.0H 2 O, while the DBS-containing one exhibits the common LDH compound-like structure. The contact angle measurement indicates the evident hydrophobic properties of DBS-containing nanocomposite, compared with SO 4 2- -containing product, due to the modification of the internal and external surface of LDHs by the organic hydrophobic chain of DBS. - Graphical abstract: For Zn 2+ -Fe 2+ -Fe 3+ GR2(SO 4 2- ), according to the derived chemical formula, Fe 3+ was arranged at 1a (0, 0, 0) position, while all Zn 2+ were in 2d position with the occupancy 0.645, and the left part of 2d positions were taken by Fe 2+ /Fe 3+

Seed priming with iron and zinc in bread wheat: effects in germination, mitosis and grain yield.

Science.gov (United States)

Reis, Sara; Pavia, Ivo; Carvalho, Ana; Moutinho-Pereira, José; Correia, Carlos; Lima-Brito, José

2018-07-01

Currently, the biofortification of crops like wheat with micronutrients such as iron (Fe) and zinc (Zn) is extremely important due to the deficiencies of these micronutrients in the human diet and in soils. Agronomic biofortification with Fe and Zn can be done through different exogenous strategies such as soil application, foliar spraying, and seed priming. However, the excess of these micronutrients can be detrimental to the plants. Therefore, in the last decade, a high number of studies focused on the evaluation of their phytotoxic effects to define the best strategies for biofortification of bread wheat. In this study, we investigated the effects of seed priming with different dosages (1 mg L -1 to 8 mg L -1 ) of Fe and/or Zn in germination, mitosis and yield of bread wheat cv. 'Jordão' when compared with control. Overall, our results showed that: micronutrient dosages higher than 4 mg L -1 negatively affect the germination; Fe and/or Zn concentrations higher than 2 mg L -1 significantly decrease the mitotic index and increase the percentage of dividing cells with anomalies; treatments performed with 8 mg L -1 of Fe and/or 8 mg L -1 Zn caused negative effects in germination, mitosis and grain yield. Moreover, seed priming with 2 mg L -1 Fe + 2 mg L -1 Zn has been shown to be non-cytotoxic, ensuring a high rate of germination (80%) and normal dividing cells (90%) as well as improving tillering and grain yield. This work revealed that seed priming with Fe and Zn micronutrients constitutes a useful and alternative approach for the agronomic biofortification of bread wheat.

Iron, zinc, copper and magnesium nutritional status in Mexican children aged 1 to 11 years.

Science.gov (United States)

Morales-Ruán, Ma del Carmen; Villalpando, Salvador; García-Guerra, Armando; Shamah-Levy, Teresa; Robledo-Pérez, Ricardo; Avila-Arcos, Marco Antonio; Rivera, Juan A

2012-01-01

To describe the micronutrient nutritional status of a national sample of 1-11 year old Mexican children surveyed in 2006 in National Health and Nutrition Survey (ENSANUT 2006) and their association with dietary and sociodemographic factors. Serum samples were used (n=5 060) to measure the concentrations of ferritin, transferrin receptor, zinc, copper and magnesium. Prevalence of deficiencies in 1-4 and 5-11y old children were for iron (using low ferritin) 26.0 and 13.0%; zinc, 28.1 and 25.8%, respectively; and copper, ≈30% in both age groups. Magnesium low serum concentrations (MLSC), were found in 12.0% and 28.4% of the children, respectively. Being beneficiary of Liconsa (OR=0.32; C.I.95%, 0.17-0.61) or belonging to higher socioeconomic status (OR=0.63; C.I.95%, 0.41-0.97) were protective against iron deficiency. Increasing age (OR=0.59; C.I.95%, 1.19-1.32) and living in the Central Region (OR=0.59; C.I.95%, 0.36-0.97) were protective against MLSC. Deficiencies of iron and zinc are serious public health problems in Mexican children.

Transgenic expression of phytase in wheat endosperm increases bioavailability of iron and zinc in grains.

Science.gov (United States)

Abid, Nabeela; Khatoon, Asia; Maqbool, Asma; Irfan, Muhammad; Bashir, Aftab; Asif, Irsa; Shahid, Muhammad; Saeed, Asma; Brinch-Pedersen, Henrik; Malik, Kauser A

2017-02-01

Phytate is a major constituent of wheat seeds and chelates metal ions, thus reducing their bioavailability and so the nutritional value of grains. Transgenic plants expressing heterologous phytase are expected to enhance degradation of phytic acid stored in seeds and are proposed to increase the in vitro bioavailability of mineral nutrients. Wheat transgenic plants expressing Aspergillus japonicus phytase gene (phyA) in wheat endosperm were developed till T 3 generation. The transgenic lines exhibited 18-99 % increase in phytase activity and 12-76 % reduction of phytic acid content in seeds. The minimum phytic acid content was observed in chapatti (Asian bread) as compared to flour and dough. The transcript profiling of phyA mRNA indicated twofold to ninefold higher expression as compared to non transgenic controls. There was no significant difference in grain nutrient composition of transgenic and non-transgenic seeds. In vitro bioavailability assay for iron and zinc in dough and chapatti of transgenic lines revealed a significant increase in iron and zinc contents. The development of nutritionally enhanced cereals is a step forward to combat nutrition deficiency for iron and zinc in malnourished human population, especially women and children.

Micronutrient supplementation adherence and influence on the prevalences of anemia and iron, zinc and vitamin A deficiencies in preemies with a corrected age of six months

Directory of Open Access Journals (Sweden)

Brunnella Alcantara Chagas de Freitas

Full Text Available OBJECTIVE: To analyze adherence to the recommended iron, zinc and multivitamin supplementation guidelines for preemies, the factors associated with this adherence, and the influence of adherence on the occurrence of anemia and iron, zinc and vitamin A deficiencies. METHODS: This prospective cohort study followed 58 preemies born in 2014 until they reached six months corrected age. The preemies were followed at a referral secondary health service and represented 63.7% of the preterm infants born that year. Outcomes of interest included high or low adherence to iron, zinc and multivitamin supplementation guidelines; prevalence of anemia; and prevalences of iron, zinc, and vitamin A deficiencies. The prevalence ratios were calculated by Poisson regression. RESULTS: Thirty-eight (65.5% preemies presented high adherence to micronutrient supplementation guidelines. At six months of corrected age, no preemie had vitamin A deficiency. The prevalences of anemia, iron deficiency and zinc deficiency were higher in the low-adherence group but also concerning in the high-adherence group. Preemies with low adherence to micronutrient supplementation guidelines were 2.5 times more likely to develop anemia and 3.1 times more likely to develop zinc deficiency. Low maternal education level increased the likelihood of nonadherence to all three supplements by 2.2 times. CONCLUSIONS: Low maternal education level was independently associated with low adherence to iron, zinc and vitamin A supplementation guidelines in preemies, which impacted the prevalences of anemia and iron and zinc deficiencies at six months of corrected age.

The Practical Realisation of Zinc-Iron CMA Coatings

DEFF Research Database (Denmark)

Jensen, Jens Dahl

1998-01-01

A detailed study of the production opportunities for composition modulated alloy electrodeposits by pulsed current techniques with Zinc-Iron alloys is reported. It is shown that by using a chloride solution, with the additional capability of variable agitation rates, a full range of alloy...... compositions is possible with nanometre layering attainable using single or double bath methods. Furthermore, by the use of a high concentration of ammonium chloride ostensibly as "conductivity" salt, the mechanism of deposition may be modified through control of a thin cathode oxide/hydroxide film....

Impact of Microcystis aeruginosa Exudate on the Formation and Reactivity of Iron Oxide Particles Following Fe(II) and Fe(III) Addition.

Science.gov (United States)

Garg, Shikha; Wang, Kai; Waite, T David

2017-05-16

Impact of the organic exudate secreted by a toxic strain of Microcystis aeruginosa on the formation, aggregation, and reactivity of iron oxides that are formed on addition of Fe(II) and Fe(III) salts to a solution of the exudate is investigated in this study. The exudate has a stabilizing effect on the particles formed with decreased aggregation rate and increased critical coagulant concentration required for diffusion-limited aggregation to occur. These results suggest that the presence of algal exudates from Microcystis aeruginosa may significantly influence particle aggregation both in natural water bodies where Fe(II) oxidation results in oxide formation and in water treatment where Fe(III) salts are commonly added to aid particle growth and contaminant capture. The exudate also affects the reactivity of iron oxide particles formed with exudate coated particles undergoing faster dissolution than bare iron oxide particles. This has implications to iron availability, especially where algae procure iron via dissolution of iron oxide particles as a result of either reaction with reducing moieties, light-mediated ligand to metal charge transfer and/or reaction with siderophores. The increased reactivity of exudate coated particles is attributed, for the most part, to the smaller size of these particles, higher surface area and increased accessibility of surface sites.

Iron fertilization with FeEDDHA : the fate and effectiveness of FeEDDHA chelates in soil-plant systems

OpenAIRE

Schenkeveld, W.D.C.

2010-01-01

Iron deficiency chlorosis is a nutritional disorder in plants which reduces crop yields both quantitatively and qualitatively, and causes large economic losses. It occurs world-wide, predominantly in plants grown on calcareous soils, as a result of a limited bioavailability of iron related to the poor solubility of iron at high soil-pH (7.5-8.5). Iron fertilizers based on FeEDDHA (iron ethylene diamine-N,N'-bis(hydroxy phenyl acetic acid)) chelates are among the most efficient in preventing a...

Comparing soluble ferric pyrophosphate to common iron salts and chelates as sources of bioavailable iron in a Caco-2 cell culture model.

Science.gov (United States)

Zhu, Le; Glahn, Raymond P; Nelson, Deanna; Miller, Dennis D

2009-06-10

Iron bioavailability from supplements and fortificants varies depending upon the form of the iron and the presence or absence of iron absorption enhancers and inhibitors. Our objectives were to compare the effects of pH and selected enhancers and inhibitors and food matrices on the bioavailability of iron in soluble ferric pyrophosphate (SFP) to other iron fortificants using a Caco-2 cell culture model with or without the combination of in vitro digestion. Ferritin formation was the highest in cells treated with SFP compared to those treated with other iron compounds or chelates. Exposure to pH 2 followed by adjustment to pH 7 markedly decreased FeSO(4) bioavailability but had a smaller effect on bioavailabilities from SFP and sodium iron(III) ethylenediaminetetraacetate (NaFeEDTA), suggesting that chelating agents minimize the effects of pH on iron bioavailability. Adding ascorbic acid (AA) and cysteine to SFP in a 20:1 molar ratio increased ferritin formation by 3- and 2-fold, respectively, whereas adding citrate had no significant effect on the bioavailability of SFP. Adding phytic acid (10:1) and tannic acid (1:1) to iron decreased iron bioavailability from SFP by 91 and 99%, respectively. The addition of zinc had a marked inhibitory effect on iron bioavailability. Calcium and magnesium also inhibited iron bioavailability but to a lesser extent. Incorporating SFP in rice greatly reduced iron bioavailability from SFP, but this effect can be partially reversed with the addition of AA. SFP and FeSO(4) were taken up similarly when added to nonfat dry milk. Our results suggest that dietary factors known to enhance and inhibit iron bioavailability from various iron sources affect iron bioavailability from SFP in similar directions. However, the magnitude of the effects of iron absorption inhibitors on SFP iron appears to be smaller than on iron salts, such as FeSO(4) and FeCl(3). This supports the hypothesis that SFP is a promising iron source for food fortification

Study on electrolytic reduction with controlled oxygen flow for iron from molten oxide slag containing FeO

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Gao Y.M.

2013-01-01

Full Text Available A ZrO2-based solid membrane electrolytic cell with controlled oxygen flow was constructed: graphite rod /[O]Fe+C saturated / ZrO2(MgO/(FeO slag/iron crucible. The feasibility of extraction of iron from molten oxide slag containing FeO at an applied voltage was investigated by means of the electrolytic cell. The effects of some important process factors on the FeO electrolytic reduction with the controlled oxygen flow were discussed. The results show that: solid iron can be extracted from molten oxide slag containing FeO at 1450ºC and an applied potential of 4V. These factors, such as precipitation and growth of solid iron dendrites, change of the cathode active area on the inner wall of the iron crucible and ion diffusion flux in the molten slag may affect the electrochemical reaction rate. The reduction for Fe2+ ions mainly appears on new iron dendrites of the iron crucible cathode, and a very small amount of iron are also formed on the MSZ (2.18% MgO partially stabilized zirconia tube/slag interface due to electronic conductance of MSZ tube. Internal electronic current through MSZ tube may change direction at earlier and later electrolytic reduction stage. It has a role of promoting electrolytic reduction for FeO in the molten slag at the earlier stage, but will lower the current efficiency at the later stage. The final reduction ratio of FeO in the molten slag can achieve 99%. A novel electrolytic method with controlled oxygen flow for iron from the molten oxide slag containing FeO was proposed. The theory of electrolytic reduction with the controlled oxygen flow was developed.

Concentration differences between serum and plasma of the elements cobalt, iron, mercury, rubidium, selenium and zinc determined by neutron activation analysis

International Nuclear Information System (INIS)

Kasperek, K.; Kiem, J.; Iyengar, G.V.; Feinendegen, L.E.

1981-01-01

The differences in concentrations of cesium, cobalt, iron, mercury, rubidium, selenium and zinc between serum and plasma were examined with the aid of instrumental neutron activation analysis. Eighty serum and plasma samples obtained from 13 donors were compared. Serum was prepared in plastic tubes immediately after clotting, and plasma was separated with heparin as anticoagulant. No significant differences in the concentrations of cesium, cobalt, mercury and selenium were observed. However, the concentrations of iron, rubidium and zinc were significantly higher in serum than in plasma. The average differences were 322, 12 and 20 ng/ml for iron, rubidium and zinc, respectively. The average differences found for cesium, rubidium and zinc were far below that which can be expected from a complete, or considerable release of these elements from platelets which aggregate or disintegrate during the clotting process in preparing serum. (orig.)

The Effect of Low Dose Iron and Zinc Intake on Child Micronutrient Status and Development during the First 1000 Days of Life: A Systematic Review and Meta-Analysis

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Nicolai Petry

2016-11-01

Full Text Available Adequate supply of micronutrients during the first 1000 days is essential for normal development and healthy life. We aimed to investigate if interventions administering dietary doses up to the recommended nutrient intake (RNI of iron and zinc within the window from conception to age 2 years have the potential to influence nutritional status and development of children. To address this objective, a systematic review and meta-analysis of randomized and quasi-randomized fortification, biofortification, and supplementation trials in women (pregnant and lactating and children (6–23 months delivering iron or zinc in doses up to the recommended nutrient intake (RNI levels was conducted. Supplying iron or zinc during pregnancy had no effects on birth outcomes. There were limited or no data on the effects of iron/zinc during pregnancy and lactation on child iron/zinc status, growth, morbidity, and psychomotor and mental development. Delivering up to 15 mg iron/day during infancy increased mean hemoglobin by 4 g/L (p < 0.001 and mean serum ferritin concentration by 17.6 µg/L (p < 0.001 and reduced the risk for anemia by 41% (p < 0.001, iron deficiency by 78% (ID; p < 0.001 and iron deficiency anemia by 80% (IDA; p < 0.001, but had no effect on growth or psychomotor development. Providing up to 10 mg of additional zinc during infancy increased plasma zinc concentration by 2.03 µmol/L (p < 0.001 and reduced the risk of zinc deficiency by 47% (p < 0.001. Further, we observed positive effects on child weight for age z-score (WAZ (p < 0.05, weight for height z-score (WHZ (p < 0.05, but not on height for age z-score (HAZ or the risk for stunting, wasting, and underweight. There are no studies covering the full 1000 days window and the effects of iron and zinc delivered during pregnancy and lactation on child outcomes are ambiguous, but low dose daily iron and zinc use during 6–23 months of age has a positive effect on child iron and zinc status.

Solid-phase extraction of copper, iron and zinc ions on Bacillus thuringiensis israelensis loaded on Dowex optipore V-493

Energy Technology Data Exchange (ETDEWEB)

Tuzen, Mustafa; Melek, Esra [Gaziosmanpasa University, Faculty of Science and Arts, Chemistry Department, 60250 Tokat (Turkey); Soylak, Mustafa [Erciyes University, Faculty of Science and Arts, Chemistry Department, 38039 Kayseri (Turkey)], E-mail: msoylak@gmail.com

2008-11-30

Bacillus thuringiensis israelensis loaded on Dowex optipore V-493 as new adsorbent for the separation-preconcentration of heavy metal ions has been proposed. The analytical conditions for the quantitative recoveries of copper(II), iron(III) and zinc(II) including pH, amounts of adsorbent, sample volume, etc. were investigated. The influences of alkaline and earth alkaline ions were also reported. The recovery values for the analytes are generally higher than 95%. The preconcentration factor was 37. The limit of detections of the analyte ions (k = 3, N = 21) were 1.14 {mu}g L{sup -1} for copper, 2.01 {mu}g L{sup -1} for iron and 0.14 {mu}g L{sup -1} for zinc. The relative standard deviations of the determinations were found to be lower than 9%. The procedure was validated by analyzing copper, iron and zinc contents in two certified reference materials, NRCC-SLRS-4 Riverine water and NIST SRM 1515 Apple leaves. Agreements between the obtained results and the certified values were achieved. The developed preconcentration method was applied in the flame atomic absorption spectrometric determination of copper, iron and zinc in several samples including a multivitamin-multimineral tablet, dialysis solutions, natural waters and some food samples.

Pituitary gland levels of mercury, selenium, iron, and zinc in an Alzheimer`s disease study

Energy Technology Data Exchange (ETDEWEB)

Cornett, C.R.; Markesbery, W.R.; Wekstein, D.R.; Ehmann, W.D. [Univ. of Kentucky, Lexington, KY (United States)

1996-12-31

Mercury, iron, selenium, and zinc imbalances have been observed in comparisons between Alzheimer`s disease (AD) and control subject brains. Analyses of the pituitary gland have demonstrated that this organ retains relatively high concentrations of trace elements, including mercury, iron, and zinc. Our previous work has shown that the pituitary glands of AD and control subjects are typically higher in these trace elements than brain samples from the same subject. Instrumental neutron activation analysis (INAA) was used to compare the pituitary trace element levels of AD and control subjects. This study also describes the intrasubject relationships of brain trace element levels to those in the pituitary gland of AD and control subjects.

The impact of aqueous washing on the ability of βFeOOH to corrode iron.

Science.gov (United States)

Watkinson, D E; Emmerson, N J

2017-01-01

Controlling the corrosion of historical and archaeological ferrous metal objects presents a significant challenge to conservators. Chloride is a major corrosion accelerator in coastal areas for historic ferrous metal structures and for the many chloride-containing archaeological objects within museums. Corrosion reactions involve the formation of akaganéite (βFeOOH) which incorporates chloride within its crystal structure and adsorbs it onto its surface. The mobility of the surface-adsorbed chloride in aqueous systems and atmospheric moisture means βFeOOH can itself cause iron to corrode. The extraction of chloride from βFeOOH by aqueous Soxhlet hot wash and aqueous room temperature washing is measured. The impact of this washing on the ability of βFeOOH to corrode iron is quantitatively investigated by determining the oxygen consumption of unwashed, Soxhlet-washed and room temperature-washed samples of βFeOOH mixed with iron powder and exposed to 80 % relative humidity. This acts as a proxy measurement for the corrosion rate of iron. The results are discussed relative to climatic factors for outdoor heritage objects and the treatment of archaeological iron in museums. Delivering better understanding of the properties of βFeOOH supports the development of evidence-based treatments and management procedures in heritage conservation.

Relative contribution of phytates, fibers, and tannins to low iron and zinc in vitro solubility in pearl millet (Pennisetum glaucum) flour and grain fractions.

Science.gov (United States)

Lestienne, Isabelle; Caporiccio, Bertrand; Besançon, Pierre; Rochette, Isabelle; Trèche, Serge

2005-10-19

In vitro digestions were performed on pearl millet flours with decreased phytate contents and on two dephytinized or nondephytinized pearl millet grain fractions, a decorticated fraction, and a bran fraction with low and high fiber and tannin contents, respectively. Insoluble residues of these digestions were then incubated with buffer or enzymatic solutions (xylanases and/or phytases), and the quantities of indigestible iron and zinc released by these different treatments were determined. In decorticated pearl millet grain, iron was chelated by phytates and by insoluble fibers, whereas zinc was almost exclusively chelated by phytates. In the bran of pearl millet grain, a high proportion of iron was chelated by iron-binding phenolic compounds, while the rest of iron as well as the majority of zinc were chelated in complexes between phytates and fibers. The low effect of phytase action on iron and zinc solubility of bran of pearl millet grain shows that, in the case of high fiber and tannin contents, the chelating effect of these compounds was higher than that of phytates.

Removal of free cyanide in waste water through complexation with Fe(II) iron followed by alkaline chlorination. Tetsu (II) ion ni yoru sakka hanno wo maeshori to suru haisuichu no yuri sian no shori

Energy Technology Data Exchange (ETDEWEB)

Nishikubo, N; Tanihara, K; Yasuda, S [Government Industrial Research Institute, Kyushu, Fukuoka (Japan)

1991-11-01

The removal treatment of free cyanide in waste water was tested by complexation with Fe(2) ion followed by alkaline chlorination and precipitation of residual iron cyano complex to study saving of sodium hypochlorite (NaClO) for alkaline chlorination. The complexation with Fe(2) ion was studied in batch treatment under the coexistence with zinc ion assuming plating waste water, while the relation between the complexation and effective chlorine consumption in alkaline chlorination was studied in continuous treatment. As a result, the effective chlorine consumption was greatly decreased by pretreatment, and a cyanic acid ion (CNO{sup {minus}}) concentration was also lower than that in conventional methods. In the case of free cyanide with lower initial concentration, the total cyanide concentration in final treated water offered sufficiently low values only by adding zinc salt, while in higher initial concentration, it reached 1 ppm or less through precipitation by adding a reductant together with zinc salt. 9 refs., 7 figs., 2 tabs.

Effectiveness of Iron Ethylenediamine-N,N'-bis(hydroxyphenylacetic) Acid (o,o-EDDHA/Fe3+) Formulations with Different Ratios of Meso and d,l-Racemic Isomers as Iron Fertilizers.

Science.gov (United States)

Alcañiz, Sara; Jordá, Juana D; Cerdán, Mar

2017-01-18

Two o,o-EDDHA/Fe 3+ formulations (meso, 93.5% w/w of meso isomer; and d,l-racemic, 91.3% w/w of d,l-racemic mixture) were prepared, and their efficacy to avoid or to relieve iron deficiency in Fe-sufficient and Fe-deficient tomato plants grown on hydroponic solution was compared with that of the current o,o-EDDHA/Fe 3+ formulations (50% of meso and d,l-racemic isomers). The effectiveness of the three o,o-EDDHA/Fe 3+ formulations was different depending on the iron nutritional status of plants. The three o,o-EDDHA/Fe 3+ formulations tested were effective in preventing iron chlorosis in healthy plants. However, the higher the meso concentration in the formulations, the higher the effectiveness in the recovery of iron chlorotic plants from iron deficiency. Accordingly, o,o-EDDHA/Fe 3+ formulations rich in meso isomer are recommended in hydroponic systems.

Moessbauer study on the distribution of iron vacancies in iron sulfide Fe sub(1-x)S

International Nuclear Information System (INIS)

Igaki, Kenzo; Sato, Masaki; Shinohara, Takeshi.

1982-01-01

The distribution of iron vacancies in iron sulfide Fe sub(1-x)S with the controlled compositions was investigated by Moessbauer spectroscopy at room temperature. Moessbauer spectrum was composed of several component spectra. These component spectra were assigned to the iron atoms with different configurations of neighboring iron vacancies. Judging from the composition dependence of intensity of each component, iron vacancies are considered to lie in every second iron layer for specimens with x between 0.125 and 0.10. For specimens with x between 0.10 and 0.09, this arrangement is nearly kept in the sample quenched from a higher temperature than 473 K, but after annealing at a lower temperature than 473 K iron vacancies are considered to lie not only in every second iron layer but also in every third iron layer or in adjacent iron layers. The iron vacancy arrangement lying in every third iron layer or in adjacent iron layers tends to dominate for specimens with x below 0.09. (author)

The kinetics of zinc coating growth on hyper-sandelin steels and ductile cast iron

Directory of Open Access Journals (Sweden)

D. Kopyciński

2007-12-01

Full Text Available The studies aimed at an analysis of the formation and growth kinetics of zinc coating on reactive silicon-killed steels in a zinc bath. The growth kinetics of the produced zinc coatings was evaluated basing on the power-law growth equation. As regards galvanizing of the surface of products, investigation was done for various steel grades and ductile iron taking into account the quality and thickness of coating. It has been proved that the chemical constitution of basis significantly influences the kinetics of growth of the individual phases in a zinc coating. This relationship was evaluated basing on the, so called, silicon and phosphorus equivalent E = (Si+2.5P.103, and coating thickness dependences were obtained.

Mineralogical Study of a Biologically-Based Treatment System That Removes Arsenic, Zinc and Copper from Landfill Leachate

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Maryam Khoshnoodi

2013-12-01

Full Text Available Mineralogical characterization by X-ray diffraction (XRD and a high throughput automated quantitative evaluation of minerals by scanning electron microscopy (QEMSCAN was conducted on samples from a sulphate-reducing biochemical reactor (BCR treating high concentrations of metals (As, Zn, Cu in smelter waste landfill seepage. The samples were also subjected to energy dispersive X-ray (EDX analysis of specific particles. The bulk analysis results revealed that the samples consisted mainly of silicate and carbonate minerals. More detailed phase analysis indicated four different classes: zinc-arsenic sulphosalts/sulphates, zinc-arsenic oxides, zinc phosphates and zinc-lead sulphosalts/sulphates. This suggests that sulphates and sulphides are the predominant types of Zn and As minerals formed in the BCR. Sphalerite (ZnS was a common mineral observed in many of the samples. In addition, X-ray point analysis showed evidence of As and Zn coating around feldspar and amphibole particles. The presence of arsenic-zinc-iron, with or without cadmium particles, indicated arsenopyrite minerals. Copper-iron-sulphide particles suggested chalcopyrite (CuFeS2 and tennantite (Cu,Fe12As4S13. Microbial communities found in each sample were correlated with metal content to describe taxonomic groups associated with high-metal samples. The research results highlight mineral grains that were present or formed at the site that might be the predominant forms of immobilized arsenic, zinc and copper.

A theoretical and experimental study of calcium, iron, zinc, cadmium, and sodium ions absorption by aspartame.

Science.gov (United States)

Mahnam, Karim; Raisi, Fatame

2017-03-01

Aspartame (L-Aspartyl-L-phenylalanine methyl ester) is a sweet dipeptide used in some foods and beverages. Experimental studies show that aspartame causes osteoporosis and some illnesses, which are similar to those of copper and calcium deficiency. This raises the issue that aspartame in food may interact with cations and excrete them from the body. This study aimed to study aspartame interaction with calcium, zinc, iron, sodium, and cadmium ions via molecular dynamics simulation (MD) and spectroscopy. Following a 480-ns molecular dynamics simulation, it became clear that the aspartame is able to sequester Fe 2+ , Ca 2+ , Cd 2+ , and Zn 2+ ions for a long time. Complexation led to increasing UV-Vis absorption spectra and emission spectra of the complexes. This study suggests a potential risk of cationic absorption of aspartame. This study suggests that purification of cadmium-polluted water by aspartame needs a more general risk assessment.

The removal of arsenate from water using iron-modified diatomite (D-Fe): isotherm and column experiments.

Science.gov (United States)

Pantoja, M L; Jones, H; Garelick, H; Mohamedbakr, H G; Burkitbayev, M

2014-01-01

Iron hydroxide supported onto porous diatomite (D-Fe) is a low-cost material with potential to remove arsenic from contaminated water due to its affinity for the arsenate ion. This affinity was tested under varying conditions of pH, contact time, iron content in D-Fe and the presence of competitive ions, silicate and phosphate. Batch and column experiments were conducted to derive adsorption isotherms and breakthrough behaviours (50 μg L(-1)) for an initial concentration of 1,000 μg L(-1). Maximum capacity at pH 4 and 17% iron was 18.12-40.82 mg of arsenic/g of D-Fe and at pH 4 and 10% iron was 18.48-29.07 mg of arsenic/g of D-Fe. Adsorption decreased in the presence of phosphate and silicate ions. The difference in column adsorption behaviour between 10% and 17% iron was very pronounced, outweighing the impact of all other measured parameters. There was insufficient evidence of a correlation between iron content and arsenic content in isotherm experiments, suggesting that ion exchange is a negligible process occurring in arsenate adsorption using D-Fe nor is there co-precipitation of arsenate by rising iron content of the solute above saturation.

Scanning tunneling microscopy on iron-chalcogenide superconductor Fe(Se, Te) single crystal

International Nuclear Information System (INIS)

Ukita, R.; Sugimoto, A.; Ekino, T.

2011-01-01

We show scanning tunneling microscopy/spectroscopy (STM/STS) results of Fe(Se, Te). STM topography shows square arrangements of spots with the lattice spacing 0.37 nm. Te and Se atoms are randomly distributed in the STM topography. The STM topography of FeTe exhibits clusters of separated iron atoms. We have investigated the iron-chalcogenide superconductor Fe(Se, Te) using a low-temperature scanning tunneling microscopy/spectroscopy (STM/STS) technique. STM topography at 4.9 K shows clear regular square arrangements of spots with the lattice spacing ∼0.37 nm, from which what we observe are attributed to Se or Te atomic plane. In the topography, brighter and darker atomic spots are randomly distributed, which are most probably due to Te and Se atoms, respectively. For the FeTe compound, the topography exhibits clusters of the bright spots probably arising from separated iron atoms distributing over several Te lattice sites. The STS measurements clarify the existence of the large-size gap with 2Δ = 0.4-0.6 eV.

Kinetics of atmospheric corrosion of mild steel, zinc, galvanized iron and aluminium at 10 exposure stations in India

International Nuclear Information System (INIS)

Natesan, M.; Venkatachari, G.; Palaniswamy, N.

2006-01-01

As a part of updating Corrosion Map of India project, atmospheric corrosion behaviour of commercially available engineering materials such as mild steel, galvanized iron, zinc and aluminium metals was studied in marine, industrial, urban, and rural environments by weight loss method at 10 exposure stations in India over a period of 5 years. The results of these studies demonstrated that galvanized iron, zinc and aluminium metals were several times more durable than mild steel. Compared to galvanized iron and zinc, aluminium provided superior protection in industrial and marine environment except at Mormugao Port Trust (MPT). It also offered much better resistance to corrosion in rural environments. At certain places, galvanized iron proved to be more durable than aluminium. The results obeyed well with the empirical kinetics equation of the form C = Kt n , where K and C are the corrosion losses in μm after 1 and 't' years of the exposure, respectively, and 'n' is a constant. Based on 'n' values, the corrosion mechanisms of these metals are predicted. The corrosion products formed on the metal samples in Chennai marine atmosphere were identified by X-ray diffraction analysis

A Program for Iron Economy during Deficiency Targets Specific Fe Proteins.

Science.gov (United States)

Hantzis, Laura J; Kroh, Gretchen E; Jahn, Courtney E; Cantrell, Michael; Peers, Graham; Pilon, Marinus; Ravet, Karl

2018-01-01

Iron (Fe) is an essential element for plants, utilized in nearly every cellular process. Because the adjustment of uptake under Fe limitation cannot satisfy all demands, plants need to acclimate their physiology and biochemistry, especially in their chloroplasts, which have a high demand for Fe. To investigate if a program exists for the utilization of Fe under deficiency, we analyzed how hydroponically grown Arabidopsis ( Arabidopsis thaliana ) adjusts its physiology and Fe protein composition in vegetative photosynthetic tissue during Fe deficiency. Fe deficiency first affected photosynthetic electron transport with concomitant reductions in carbon assimilation and biomass production when effects on respiration were not yet significant. Photosynthetic electron transport function and protein levels of Fe-dependent enzymes were fully recovered upon Fe resupply, indicating that the Fe depletion stress did not cause irreversible secondary damage. At the protein level, ferredoxin, the cytochrome- b 6 f complex, and Fe-containing enzymes of the plastid sulfur assimilation pathway were major targets of Fe deficiency, whereas other Fe-dependent functions were relatively less affected. In coordination, SufA and SufB, two proteins of the plastid Fe-sulfur cofactor assembly pathway, were also diminished early by Fe depletion. Iron depletion reduced mRNA levels for the majority of the affected proteins, indicating that loss of enzyme was not just due to lack of Fe cofactors. SufB and ferredoxin were early targets of transcript down-regulation. The data reveal a hierarchy for Fe utilization in photosynthetic tissue and indicate that a program is in place to acclimate to impending Fe deficiency. © 2018 American Society of Plant Biologists. All Rights Reserved.

Is there a strategy I iron uptake mechanism in maize?

Science.gov (United States)

Li, Suzhen; Zhou, Xiaojin; Chen, Jingtang; Chen, Rumei

2018-04-03

Iron is a metal micronutrient that is essential for plant growth and development. Graminaceous and nongraminaceous plants have evolved different mechanisms to mediate Fe uptake. Generally, strategy I is used by nongraminaceous plants like Arabidopsis, while graminaceous plants, such as rice, barley, and maize, are considered to use strategy II Fe uptake. Upon the functional characterization of OsIRT1 and OsIRT2 in rice, it was suggested that rice, as an exceptional graminaceous plant, utilizes both strategy I and strategy II Fe uptake systems. Similarly, ZmIRT1 and ZmZIP3 were identified as functional zinc and iron transporters in the maize genome, along with the determination of several genes encoding Zn and Fe transporters, raising the possibility that strategy I Fe uptake also occurs in maize. This mini-review integrates previous reports and recent evidence to obtain a better understanding of the mechanisms of Fe uptake in maize.

Enhanced Cr(VI) removal from groundwater by Fe0-H2O system with bio-amended iron corrosion

DEFF Research Database (Denmark)

Yin, Weizhao; Li, Yongtao; Wu, Jinhua

2017-01-01

Abstract A one-pot bio-iron system was established to investigate synergetic abiotic and biotic effects between iron and microorganisms on Cr(VI) removal. More diverse iron corrosion and reactive solids, such as green rusts, lepidocrocite and magnetite were found in the bio-iron system than...... transfer on the solid phase. The results also showed that the reduction of Cr(VI) by microorganisms was insignificant, indicating the adsorption/co-precipitation of Cr by iron oxides on iron surface was responsible for the overall Cr(VI) removal. Our study demonstrated that the bio-amended iron corrosion...... in the Fe0-H2O system, leading to 4.3 times higher Cr(VI) removal efficiency in the bio-iron system than in the Fe0-H2O system. The cycling experiment also showed that the Cr(VI) removal capacity of Fe0 in the bio-iron system was 12.4 times higher than that in the Fe0-H2O system. A 62 days of life...

Iron Isotope Fractionation during Fe(II) Oxidation Mediated by the Oxygen-Producing Marine Cyanobacterium Synechococcus PCC 7002

Energy Technology Data Exchange (ETDEWEB)

Swanner, E. D.; Bayer, T.; Wu, W.; Hao, L.; Obst, M.; Sundman, A.; Byrne, J. M.; Michel, F. M.; Kleinhanns, I. C.; Kappler, A.; Schoenberg, R.

2017-04-11

In this study, we couple iron isotope analysis to microscopic and mineralogical investigation of iron speciation during circumneutral Fe(II) oxidation and Fe(III) precipitation with photosynthetically produced oxygen. In the presence of the cyanobacterium Synechococcus PCC 7002, aqueous Fe(II) (Fe(II)_aq) is oxidized and precipitated as amorphous Fe(III) oxyhydroxide minerals (iron precipitates, Fe_ppt), with distinct isotopic fractionation (ε⁵⁶Fe) values determined from fitting the δ⁵⁶Fe(II)_aq (1.79‰ and 2.15‰) and the δ⁵⁶Fe_ppt (2.44‰ and 2.98‰) data trends from two replicate experiments. Additional Fe(II) and Fe(III) phases were detected using microscopy and chemical extractions and likely represent Fe(II) and Fe(III) sorbed to minerals and cells. The iron desorbed with sodium acetate (FeNaAc) yielded heavier δ⁵⁶Fe compositions than Fe(II)_aq. Modeling of the fractionation during Fe(III) sorption to cells and Fe(II) sorption to Feppt, combined with equilibration of sorbed iron and with Fe(II)_aq using published fractionation factors, is consistent with our resulting δ⁵⁶FeNaAc. The δ⁵⁶Fe_ppt data trend is inconsistent with complete equilibrium exchange with Fe(II)aq. Because of this and our detection of microbially excreted organics (e.g., exopolysaccharides) coating Feppt in our microscopic analysis, we suggest that electron and atom exchange is partially suppressed in this system by biologically produced organics. These results indicate that cyanobacteria influence the fate and composition of iron in sunlit environments via their role in Fe(II) oxidation through O₂ production, the capacity of their cell surfaces to sorb iron, and the interaction of secreted organics with Fe(III) minerals.

MicroXRF tomographic visualization of zinc and iron in the zebrafish embryo at the onset of the hatching period

Energy Technology Data Exchange (ETDEWEB)

Bourassa, Daisy; Gleber, Sophie-Charlotte; Vogt, Stefan; Shin, Chong Hyun; Fahrni, Christoph J.

2016-01-01

Transition metals such as zinc, copper, and iron play key roles in cellular proliferation, cell differentiation, growth, and development. Over the past decade, advances in synchrotron X-ray fluorescence instrumentation presented new opportunities for the three-dimensional mapping of trace metal distributions within intact specimens. Taking advantage of microXRF tomography, we visualized the 3D distribution of zinc and iron in a zebrafish embryo at the onset of the hatching period. The reconstructed volumetric data revealed distinct differences in the elemental distributions, with zinc predominantly localized to the yolk and yolk extension, and iron to various regions of the brain as well as the myotome extending along the dorsal side of the embryo. The data set complements an earlier tomographic study of an embryo at the pharyngula stage (24 hpf), thus offering new insights into the trace metal distribution at key stages of embryonic development.

Active Iron Sites of Disordered Mesoporous Silica Catalyst FeKIL-2 in the Oxidation of Volatile Organic Compounds (VOC

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Mojca Rangus

2014-05-01

Full Text Available Iron-functionalized disordered mesoporous silica (FeKIL-2 is a promising, environmentally friendly, cost-effective and highly efficient catalyst for the elimination of volatile organic compounds (VOCs from polluted air via catalytic oxidation. In this study, we investigated the type of catalytically active iron sites for different iron concentrations in FeKIL-2 catalysts using advanced characterization of the local environment of iron atoms by a combination of X-ray Absorption Spectroscopy Techniques (XANES, EXAFS and Atomic-Resolution Scanning Transmission Electron Microscopy (AR STEM. We found that the molar ratio Fe/Si ≤ 0.01 leads to the formation of stable, mostly isolated Fe3+ sites in the silica matrix, while higher iron content Fe/Si > 0.01 leads to the formation of oligonuclear iron clusters. STEM imaging and EELS techniques confirmed the existence of these clusters. Their size ranges from one to a few nanometers, and they are unevenly distributed throughout the material. The size of the clusters was also found to be similar, regardless of the nominal concentration of iron (Fe/Si = 0.02 and Fe/Si = 0.05. From the results obtained from sample characterization and model catalytic tests, we established that the enhanced activity of FeKIL-2 with the optimal Fe/Si = 0.01 ratio can be attributed to: (1 the optimal concentration of stable isolated Fe3+ in the silica support; and (2 accelerated diffusion of the reactants in disordered mesoporous silica (FeKIL-2 when compared to ordered mesoporous silica materials (FeSBA-15, FeMCM-41.

Boron solubility in Fe-Cr-B cast irons

International Nuclear Information System (INIS)

Guo Changqing; Kelly, P.M.

2003-01-01

Boron solubility in the as-cast and solution treated martensite of Fe-Cr-B cast irons, containing approximately 1.35 wt.% of boron, 12 wt.% of chromium, as well as other alloying elements, has been investigated using conventional microanalysis. The significant microstructural variations after tempering at 750 deg. C for 0.5-4 h, compared with the original as-cast and solution treated microstructures, indicated that the matrix consisted of boron and carbon supersaturated solid solutions. The boron solubility detected by electron microprobe was between 0.185-0.515 wt.% for the as-cast martensite and 0.015-0.0589 wt.% for the solution treated martensite, much higher than the accepted value of 0.005 wt.% in pure iron. These remarkable increases are thought to be associated with some metallic alloying element addition, such as chromium, vanadium and molybdenum, which have atomic diameters larger than iron, and expand the iron lattice to sufficiently allow boron atoms to occupy the interstitial sites in iron lattice

Effects of Iron Concentration Level in Extracting Solutions from Contaminated Soils on the Determination of Zinc by Flame Atomic Absorption Spectrometry with Two Background Correctors

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Christophe Waterlot

2012-01-01

Full Text Available Zinc and iron concentrations were determined after digestion, water, and three-step sequential extractions of contaminated soils. Analyses were carried out using flame absorption spectrometry with two background correctors: a deuterium lamp used as the continuum light source (D2 method and the high-speed self-reversal method (HSSR method. Regarding the preliminary results obtained with synthetic solutions, the D2 method often emerged as an unsuitable configuration for compensating iron spectral interferences. In contrast, the HSSR method appeared as a convenient and powerful configuration and was tested for the determination of zinc in contaminated soils containing high amounts of iron. Simple, fast, and interference-free method, the HSSR method allows zinc determination at the ppb level in the presence of large amounts of iron with high stability, sensitivity, and reproducibility of results. Therefore, the HSSR method is described here as a promising approach for monitoring zinc concentrations in various iron-containing samples without any pretreatment.

Does lead use the intestinal absorptive pathways of iron? Impact of iron status on murine 210Pb and 59Fe absorption in duodenum and ileum in vivo

International Nuclear Information System (INIS)

Elsenhans, Bernd; Janser, Heinz; Windisch, Wilhelm; Schuemann, Klaus

2011-01-01

Highlights: → Absorption of 210 Pb increases much less than that of 59 Fe in murine duodena. → 210 Pb-absorption is almost equally high in murine duodenal and ileal segments. → 59 Fe absorption is much lower in ileal than in duodenal segments. → There must be an additional DMT1-independet pathway for intestinal Pb absorption. -- Abstract: Background: Human isotope studies and epidemiological trials are controversial as to whether lead absorption shares the absorptive pathways of iron and whether body lead content can be reduced by iron supplementation. Aim: To compare the impact of iron-deficiency on 59 Fe- and 210 Pb-absorption rates in duodenal and ileal segments. Methods: 59 Fe- and 210 Pb-absorption was determined in ligated duodenal and ileal segments from juvenile and adult iron-deficient and iron-adequate C57Bl6 wild-type mice (n = 6) in vivo at luminal concentrations corresponding to human exposure (Fe: 1 and 100 μmol/L; Pb: 1 μmol/L). Results and discussion: 59 Fe-absorption increased 10-15-fold in iron-deficient duodena from adult and adolescent mice. Ileal 59 Fe-absorption was 4-6 times lower than in iron-adequate duodena showing no adaptation to iron-deficiency. This in accordance to expectation as the divalent metal transport 1 (DMT1) shows low ileal expression levels. Juvenile 59 Fe-absorption was about twice as high as in adult mice. In contrast, duodenal 210 Pb-absorption was increased only 1.5-1.8-fold in iron-deficiency in juvenile and adult mice and, again in contrast to 59 Fe, ileal 210 Pb-absorption was as high as in iron-adequate duodena. Conclusions: The findings suggest a DMT1-independent pathway to mediate lead absorption along the entire small intestine in addition to DMT1-mediated duodenal uptake. Ileal lead absorption appears substantial, due the much longer residence of ingesta in the distal small intestine. Differences in lead-solubility and -binding to luminal ligands can, thus, explain the conflicting findings regarding the

Bioavailability of iron and zinc from human diets: Nutrient delivery technology salt fortification in human nutrition

International Nuclear Information System (INIS)

Raghuramulu, N.

1992-01-01

Iodine deficiency disorders (IDD), iron deficiency anaemia(IDA) and zinc deficiency are common problems in India. The discussions in this paper centers on the selection of the vehicles which could be used to successfully deliver essential nutrients into the daily diet of the general population of india and the identification of compounds which inhibit the intestinal absorption of zinc. 40 refs, 11 tabs

Recycling of Zn-containing Fe-bearing steelmaking waste by the reducing smelting process in pig iron. I. Laboratory tests

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Kendera Ján

1997-09-01

Full Text Available Results of the laboratory test treatment of the zinc containing steelwork dusts in a hot liquid pig iron are described. These results show that it is necessary to use an external reductant. The zinc content of the dust emission is ca. 20 %. The charge of the steel-works dusts diminished the Si and Mn content of pig iron.

The behavior of iron and zinc stable isotopes accompanying the subduction of mafic oceanic crust: A case study from Western Alpine ophiolites

Science.gov (United States)

Inglis, Edward C.; Debret, Baptiste; Burton, Kevin W.; Millet, Marc-Alban; Pons, Marie-Laure; Dale, Christopher W.; Bouilhol, Pierre; Cooper, Matthew; Nowell, Geoff M.; McCoy-West, Alex J.; Williams, Helen M.

2017-07-01

Arc lavas display elevated Fe3+/ΣFe ratios relative to MORB. One mechanism to explain this is the mobilization and transfer of oxidized or oxidizing components from the subducting slab to the mantle wedge. Here we use iron and zinc isotopes, which are fractionated upon complexation by sulfide, chloride, and carbonate ligands, to remark on the chemistry and oxidation state of fluids released during prograde metamorphism of subducted oceanic crust. We present data for metagabbros and metabasalts from the Chenaillet massif, Queyras complex, and the Zermatt-Saas ophiolite (Western European Alps), which have been metamorphosed at typical subduction zone P-T conditions and preserve their prograde metamorphic history. There is no systematic, detectable fractionation of either Fe or Zn isotopes across metamorphic facies, rather the isotope composition of the eclogites overlaps with published data for MORB. The lack of resolvable Fe isotope fractionation with increasing prograde metamorphism likely reflects the mass balance of the system, and in this scenario Fe mobility is not traceable with Fe isotopes. Given that Zn isotopes are fractionated by S-bearing and C-bearing fluids, this suggests that relatively small amounts of Zn are mobilized from the mafic lithologies in within these types of dehydration fluids. Conversely, metagabbros from the Queyras that are in proximity to metasediments display a significant Fe isotope fractionation. The covariation of δ56Fe of these samples with selected fluid mobile elements suggests the infiltration of sediment derived fluids with an isotopically light signature during subduction.

Immobilization of bacterial S-layer proteins from Caulobacter crescentus on iron oxide-based nanocomposite: synthesis and spectroscopic characterization of zincite-coated Fe₂O₃ nanoparticles.

Science.gov (United States)

Habibi, Neda

2014-05-05

Zinc oxide was coated on Fe2O3 nanoparticles using sol-gel spin-coating. Caulobacter crescentus have a crystalline surface layer (S-layer), which consist of one protein or glycoprotein species. The immobilization of bacterial S-layers obtained from C. crescentus on zincite-coated nanoparticles of iron oxide was investigated. The SDS PAGE results of S-layers isolated from C. crescentus showed the weight of 50 KDa. Nanoparticles of the Fe2O3 and zinc oxide were synthesized by a sol-gel technique. Fe2O3 nanoparticles with an average size of 50 nm were successfully prepared by the proper deposition of zinc oxide onto iron oxide nanoparticles surface annealed at 450 °C. The samples were characterized by field-emission scanning electron microscope (FESEM), atomic force microscopy (AFM), powder X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FT-IR). Copyright © 2014 Elsevier B.V. All rights reserved.

Effect of Organic Substances on the Efficiency of Fe(Ii to Fe(Iii Oxidation and Removal of Iron Compounds from Groundwater in the Sedimentation Process

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Krupińska Izabela

2017-09-01

Full Text Available One of the problems with iron removal from groundwater is organic matter. The article presents the experiments involved groundwater samples with a high concentration of total iron - amounting to 7.20 mgFe/dm3 and an increased amount of organic substances (TOC from 5.50 to 7.50 mgC/dm3. The water samples examined differed in terms of the value of the ratio of the TOC concentration and the concentration of total iron (D. It was concluded that with increase in the coexistence ratio of organic substances and total iron in water (D = [TOC]/[Fetot], efficiency of Fe(II to Fe(III oxidization with dissolved oxygen decreased, while the oxidation time was increasing. This rule was not demonstrated for potassium manganate (VII when used as an oxidizing agent. The application of potassium manganate (VII for oxidation of Fe(II ions produced the better results in terms of total iron concentration reduction in the sedimentation process than the oxidation with dissolved oxygen.

Effect of Organic Substances on the Efficiency of Fe(Ii) to Fe(Iii) Oxidation and Removal of Iron Compounds from Groundwater in the Sedimentation Process

Science.gov (United States)

Krupińska, Izabela

2017-09-01

One of the problems with iron removal from groundwater is organic matter. The article presents the experiments involved groundwater samples with a high concentration of total iron - amounting to 7.20 mgFe/dm3 and an increased amount of organic substances (TOC from 5.50 to 7.50 mgC/dm3). The water samples examined differed in terms of the value of the ratio of the TOC concentration and the concentration of total iron (D). It was concluded that with increase in the coexistence ratio of organic substances and total iron in water (D = [TOC]/[Fetot]), efficiency of Fe(II) to Fe(III) oxidization with dissolved oxygen decreased, while the oxidation time was increasing. This rule was not demonstrated for potassium manganate (VII) when used as an oxidizing agent. The application of potassium manganate (VII) for oxidation of Fe(II) ions produced the better results in terms of total iron concentration reduction in the sedimentation process than the oxidation with dissolved oxygen.

Ferrite formation in the MeO – Fe2O3 (Me - Zn, Cd, Cu) systems and its impact for the zinc hydrometallurgy

International Nuclear Information System (INIS)

Boyanov, Boyan S.; Cherkezova-Zheleva, Zara

2011-01-01

Study on the solid state interactions between MeO (Me - Zn, Cd, Cu) and α-Fe 2 O 3 is very important for metallurgy as well as for the preparation of magnetic materials and new catalysts. Zinc, copper and cadmium ferrites are obtained by the conventional ceramic technology. Chemical, DTA and TG analyses, Mössbauer spectroscopy and X-ray phase analysis have been used in the study of intermediate and final products of solid state interactions. The kinetics of formation of MeFe 2 O 4 is investigated by different kinetics equations and the activation energy values are obtained. The ferrite formation process in the system ZnO - α-Fe 2 O 3 and the effectiveness of zinc extraction during the hydrometallurgical treatment of the zinc calcine and the fuming of zinc containing slags are discussed. Key words: ferrites, zinc, copper, cadmium, kinetics, zinc concentrate, Mössbauer spectroscopy, Xray phase analysis

Different behaviour of 63Ni and 59Fe during absorption in iron-deficient and iron-adequate jejunal rat segments ex vivo

International Nuclear Information System (INIS)

Mueller-Fassbender, M.; Elsenhans, B.; McKie, A.T.; Schuemann, K.

2003-01-01

Nickel exhibits low oral toxicity. It shares the absorptive pathways for iron, though there are substantial quantitative differences in handling of both metals. To analyse these differences more closely, jejunal segments from iron-deficient and iron-adequate rats were luminally perfused ex vivo with 59 Fe and 63 Ni at six different concentrations (1-500 μmo1/l) under steady state conditions. 59 Fe over-all absorption increased 2.0-4.6-fold in iron-deficiency at luminal concentrations between 1 and 100 μmol/l, while 63 Ni absorption increased to a much lower extent (2.6-fold at 1 μmol/l and 1.5-fold at higher luminal concentrations). Moreover, there was a 5-7-fold higher concentration for 63 Ni in the jejunal tissue than in the absorbate at luminal concentrations above 50 μmol/l which was not observed at 1 μmol 63 Ni/l and not for 59 Fe. 63 Ni tissue load showed a linear and a saturable fraction. In iron-deficiency the saturable 63 Ni fraction increased 4-fold as compared to only 1.5-fold increments for 59 Fe. Moreover, a substantially higher share of 63 Ni was retained in the jejunal tissue at high as compare to low luminal concentrations after perfusion had been continued without luminal radioactivity. This was not found for 59 Fe and suggests a concentration-dependent block of 63 Ni export across the enterocytes' basolateral membrane. To explain these results one may speculate that 63 Ni may bind more tightly to tissue ligands than 59 Fe due to the higher thermodynamic and kinetic stability of nickel complexes. In particular, nickel may bind to a basolateral population of metal carriers and block its own basolateral transfer in a concentration-dependent manner. Tight 63 Ni binding to non-specific jejunal ligands is responsible for the unaltered high linear fraction of jejunal 63 Ni load in iron-deficient and iron-adequate segments. Binding of 63 Ni to food and tissue ligands in the small intestine may, thus, be a likely explanation for the low oral nickel

Oxidative degradation stability and hydrogen sulfide removal performance of dual-ligand iron chelate of Fe-EDTA/CA.

Science.gov (United States)

Miao, Xinmei; Ma, Yiwen; Chen, Zezhi; Gong, Huijuan

2017-09-05

Catalytic oxidation desulfurization using chelated iron catalyst is an effective method to remove H 2 S from various gas streams including biogas. However, the ligand of ethylenediaminetetraacetic acid (EDTA), which is usually adopted to prepare chelated iron catalyst, is liable to be oxidative degraded, and leads to the loss of desulfurization performance. In order to improve the degradation stability of the iron chelate, a series of iron chelates composed of two ligands including citric acid (CA) and EDTA were prepared and the oxidative degradation stability as well as desulfurization performance of these chelated iron catalysts were studied. Results show that the iron chelate of Fe-CA is more stable than Fe-EDTA, while for the desulfurization performance, the situation is converse. For the dual-ligand iron chelates of Fe-EDTA/CA, with the increase of mol ratio of CA to EDTA in the iron chelate solution, the oxidative degradation stability increased while the desulfurization performance decreased. The results of this work showed that Fe-EDTA/CA with a mol ratio of CA:EDTA = 1:1 presents a relative high oxidative degradation stability and an acceptable desulfurization performance with over 90% of H 2 S removal efficiency.

Response of Some Bread Wheat Cultivars to Foliar Application of Zn and Fe Different Forms in Two Locations with Different Soil Properties

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E Arazmjoo

2018-05-01

Full Text Available Introduction Zinc (Zn and iron (Fe are essential mineral nutrients for plant and human growth, and dietary Zn and Fe deficiencies are a worldwide nutritional problem. The Recommended Dietary Allowance (RDA of Zn and Fe are 15 mg and 10 mg per day for human, respectively. However, micronutrient deficiencies affect more than half of the world’s population, especially women and preschool children. Iron is one of the most important micronutrients, and approximately two billion people suffer from iron deficiency worldwide. Zinc deficiency is also considered to be quite common and affects newborn, children, pregnant women and elderly. Micronutrient malnutrition in human in developing countries is derived from deficiencies of these elements in staple food. It is believed that increasing the micronutrient concentrations in these crops could increase the dietary intake of these elements in these regions significantly. More than 80% of arable soils in Iran are zinc-deficient with an average yield depression of around 50%. It is, therefore, highly important to develop cost-effective and quick solutions to the Zn and Fe deficiency problem. Materials and Methods In order to evaluate the effect of foliar application of zinc and iron different forms on yield components, phonological and morphological traits and grain yield of some wheat cultivars in two locations with different physico-chemical soil properties, two experiments in factorial arranged in randomized complete block design with three replications conducted during 2015-16 cropping season. Experimental treatments were included: wheat cultivars Roshan, Roshan Back cross (old cultivars, Bam and Ofogh (new cultivars, zinc application in three levels of foliar application of water (control, zinc sulfate and chelated zinc and iron application in three levels of foliar application of water (control, iron sulfate and chelated iron (equivalent to 2.5 kg ha-1. The first experiment was conducted at the

Study of solid state interactions in the systems ZnFe2O4 - CaO, ZnFe2O4 - MgO and zinc cake with CaO and MgO

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Peltekov A.B.

2013-01-01

Full Text Available The solid state interactions of CaO and MgO with synthetic and industrial ZnFe2O4 (in zinc cake have been studied using chemical, XRD analysis and Mössbauer spectroscopy. The exchange reactions in the systems ZnFe2O4 - CaO and ZnFe2O4 - MgO have been investigated in the range of 850-1200ºC and duration up to 180 min. It has been established that Ca2+ and Mg2+ ions exchange Zn2+ in ferrite partially and the solubility of zinc in a 7% sulfuric acid solution increases. The possibilities for utilization of the obtained results in zinc hydrometallurgy have been discussed.

The concentration of heavy metals: zinc, cadmium, lead, copper, mercury, iron and calcium in head hair of a randomly selected sample of Kenyan people

International Nuclear Information System (INIS)

Wandiga, S.O.; Jumba, I.O.

1982-01-01

An intercomparative analysis of the concentration of heavy metals:zinc, cadmium, lead, copper, mercury, iron and calcium in head hair of a randomly selected sample of Kenyan people using the techniques of atomic absorption spectrophotometry (AAS) and differential pulse anodic stripping voltammetry (DPAS) has been undertaken. The percent relative standard deviation for each sample analysed using either of the techniques show good sensitivity and correlation between the techniques. The DPAS was found to be slightly sensitive than the AAs instrument used. The recalculated body burden rations of Cd to Zn, Pb to Fe reveal no unusual health impairement symptoms and suggest a relatively clean environment in Kenya.(author)

Manganese, iron and copper contents in leaves of maize plants ...

African Journals Online (AJOL)

Micronutrients such as boron (B), copper (Cu), iron (Fe), manganese (Mn) and zinc (Zn) play important physiological roles in humans and animals. Zn and B are the micronutrients most often deficient in maize, in Iran. A completely randomized factorial block design experiment was carried out at Fars province of Iran during ...

Spatial evolution of Zn-Fe-Pb isotopes of sphalerite within a single ore body: A case study from the Dongshengmiao ore deposit, Inner Mongolia, China

Science.gov (United States)

Gao, Zhaofu; Zhu, Xiangkun; Sun, Jian; Luo, Zhaohua; Bao, Chuang; Tang, Chao; Ma, Jianxiong

2018-01-01

Analyses of sphalerite minerals from the characteristic brecciated Zn-Pb ores of the main ore body in the giant Dongshengmiao deposit have revealed variations in δ66Zn from 0.17 to 0.40‰ and in δ56Fe from -1.78 to -0.35‰. Further, the investigated pyrrhotite samples have iron that is isotopically similar to that of associated sphalerite minerals. The most distinctive pattern revealed by the zinc and iron isotope data is the lateral trend of increasing δ66Zn and δ56Fe values from southwest to northeast within the main ore body. The lead isotopic homogeneity of ore sulfides from the main ore body suggests that there is only one significant source for metal, thus precluding the mixing of multiple metal sources as the key factor controlling spatial variations of zinc and iron isotopes. The most likely control on spatial variations is Rayleigh fractionation during hydrothermal fluid flow, with lighter Zn and Fe isotopes preferentially incorporated into the earliest sulfides to precipitate from fluids. Precipitations of sphalerite and pyrrhotite have played vital roles in the Zn and Fe isotopic variations, respectively, of the ore-forming system. Accordingly, the larger isotopic variability for Fe than Zn within the same hydrothermal system perhaps resulted from a larger proportion of precipitation for pyrrhotite than for sphalerite. The lateral trend pattern revealed by the zinc and iron isotope data is consistent with the occurrence of a cystic-shaped breccia zone, which is characterized by marked elevation in Cu. The results further confirm that Zn and Fe isotopes can be used as a vectoring tool for mineral prospecting.

Interactions of cadmium with copper, zinc, and iron in different organs and tissues of the rat

Energy Technology Data Exchange (ETDEWEB)

Julshamn, K.; Utne, F.; Brackkan, O.R.

1977-01-01

The effect of cadmium on tissue concentrations of iron, zinc and copper was studied in male rats. Two littermate groups were fed a stock diet with or without a supplement of 100 ..mu..g cadmium per g. Every three weeks ten animals from each group were sampled and the liver, kidneys, heart, lungs, spleen, testes, muscle, fur, feces and urine were individually analyzed. Except for the fur, all the other organs showed highly significantly increased levels of cadmium when compared with the control group. The iron levels were significantly depressed in all organs. As the content in the feces remained unchanged and the urinary excretion showed an increase, it could be concluded that the cadmium supplementation resulted in a depletion of the body stores of iron. The zinc levels showed a significant increase in the liver and testes and a correspondingly significant decrease in the spleen. The levels of copper generally showed no significant changes.

The synthesis, structure and reactivity of iron-bismuth complexes : Potential Molecular Precursors for Multiferroic BiFeO3

OpenAIRE

Wójcik, Katarzyna

2009-01-01

The thesis presented here is focused on the synthesis of iron-bismuth alkoxides and siloxides as precursors for multiferroic BiFeO3 systems. Spectrum of novel cyclopentadienyl substituted iron-bismuth complexes of the general type [{Cpy(CO)2Fe}BiX2], as potential precursors for cyclopentadienyl iron-bismuth alkoxides or siloxides [{Cpy(CO)2Fe}Bi(OR)2] (R-OtBu, OSiMe2tBu), were obtained and characterised. The use of wide range of cyclopentadienyl rings in the iron carbonyl compounds allowed fo...

Environmental application of millimeter-scale sponge iron (s-Fe(0)) particles (II): the effect of surface copper.

Science.gov (United States)

Ju, Yongming; Liu, Xiaowen; Liu, Runlong; Li, Guohua; Wang, Xiaoyan; Yang, Yanyan; Wei, Dongyang; Fang, Jiande; Dionysiou, Dionysios D

2015-04-28

To enhance the catalytic reactivity of millimeter-scale particles of sponge iron (s-Fe(0)), Cu(2+) ions were deposited on the surface of s-Fe(0) using a simple direct reduction reaction, and the catalytic properties of the bimetallic system was tested for removal of rhodamine B (RhB) from an aqueous solution. The influence of Cu(0) loading, catalyst dosage, particle size, initial RhB concentration, and initial pH were investigated, and the recyclability of the catalyst was also assessed. The results demonstrate that the 3∼5 millimeter s-Fe(0) particles (s-Fe(0)(3∼5mm)) with 5wt% Cu loading gave the best results. The removal of RhB followed two-step, pseudo-first-order reaction kinetics. Cu(0)-s-Fe(0) showed excellent stability after five reuse cycles. Cu(0)-s-Fe(0) possesses great advantages compared to nanoscale zero-valent iron, iron power, and iron flakes as well as its bimetals. The surface Cu(0) apparently catalyzes the production of reactive hydrogen atoms for indirect reaction and generates Fe-Cu galvanic cells that enhance electron transfer for direct reaction. This bimetallic catalyst shows great potential for the pre-treatment of recalcitrant wastewaters. Additionally, some oxides containing iron element are selected to simulate the adsorption process. The results prove that the adsorption process of FeOOH, Fe2O3 and Fe3O4 played minor role for the removal of RhB. Copyright © 2015 Elsevier B.V. All rights reserved.

Serum and tissue contents of copper, calcium, iron and magnesium elements in cases of acne vulgaris after zinc therapy

International Nuclear Information System (INIS)

El-Said, S.M.; El-Bedewi, A.F.

2002-01-01

The effect of zinc therapy on some trace elements contents in serum and skin was studied in normal group (forty) and patients group with acne vulgaris (26 males and 14 females) with age ranged between 14-30 year. They were under medical treatment with 330 mg oral zinc sulfate for 12 weeks. Highly significant decreases in both serum and tissue contents of copper and calcium were detected, as well as, highly significant decrease in the serum content of magnesium was recorded. The serum content of iron was highly significantly increased and that for tissue content was slightly significantly increased. It could be concluded that zinc therapy could be valuable through modulation of copper. calcium, iron and magnesium in acne patients

Li4FeH6: Iron-containing complex hydride with high gravimetric hydrogen density

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Hiroyuki Saitoh

2014-07-01

Full Text Available Li4FeH6, which has the highest gravimetric hydrogen density of iron-containing complex hydrides reported so far, is synthesized by hydrogenation of a powder mixture of iron and LiH above 6.1 GPa at 900 °C. In situ synchrotron radiation X-ray diffraction measurements reveal that while kinetics require high temperature and thus high pressure for the synthesis, Li4FeH6 is expected to be thermodynamically stable slightly below room temperature at ambient pressure; further synthetic studies to suppress the kinetic effects may enable us to synthesize Li4FeH6 at moderate pressures. Li4FeH6 can be recovered at ambient conditions where Li4FeH6 is metastable.

{Fe6O2}-Based Assembly of a Tetradecanuclear Iron Nanocluster

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Svetlana G. Baca

2011-01-01

Full Text Available The tetradecanuclear FeIII pivalate nanocluster [Fe14O10(OH4(Piv18], comprising a new type of metal oxide framework, has been solvothermally synthesized from a hexanuclear iron pivalate precursor in dichlormethane/acetonitrile solution. Magnetic measurements indicate the presence of very strong antiferromagnetic interactions in the cluster core.

Electrochemical deposition of iron sulfide thin films and heterojunction diodes with zinc oxide

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Shoichi Kawai

2014-03-01

Full Text Available Iron sulfide thin films were fabricated by the electrochemical deposition method from an aqueous solution containing FeSO4 and Na2S2O3. The composition ratio obtained was Fe:S:O = 36:56:8. In the photoelectrochemical measurement, a weak negative photo-current was observed for the iron sulfide films, which indicates that its conduction type is p-type. No peaks were observed in X-ray diffraction pattern, and thus the deposited films were considered to be amorphous. For a heterojunction with ZnO, rectification properties were confirmed in the current-voltage characteristics. Moreover, the current was clearly enhanced under AM1.5 illumination.

Environmental application of millimetre-scale sponge iron (s-Fe{sup 0}) particles (I): Pretreatment of cationic triphenylmethane dyes

Energy Technology Data Exchange (ETDEWEB)

Ju, Yongming, E-mail: juyongming@scies.org [South China Institute of Environmental Sciences, the Ministry of Environmental Protection of PRC, Guangzhou 510655 (China); Liu, Xiaowen, E-mail: liuxiaowen@scies.org [South China Institute of Environmental Sciences, the Ministry of Environmental Protection of PRC, Guangzhou 510655 (China); Li, Zhaoyong; Kang, Juan; Wang, Xiaoyan; Zhang, Yukui; Fang, Jiande [South China Institute of Environmental Sciences, the Ministry of Environmental Protection of PRC, Guangzhou 510655 (China); Dionysiou, Dionysios D., E-mail: dionysios.d.dionysiou@uc.edu [Environmental Engineering and Science Program, University of Cincinnati, Cincinnati, OH 45221-0012 (United States)

2015-02-11

Graphical abstract: - Highlights: • Millimetric s-Fe{sup 0} particles effectively reduce BG, MG, CV, and EV dyes. • s-Fe{sup 0} displays similar contaminant removal efficiency compared to nZVI. • s-Fe{sup 0} shows greater economic advantages than nZVI, iron powder, and iron scurf. • The reductive mechanism of BG over s-Fe{sup 0} under US condition is elucidated. - Abstract: To investigate the removal capability of millimetric zero valent iron (mmZVI), sponge iron (s-Fe{sup 0}) particles were characterized with XRD, XPS, TEM, HRSEM and EDS techniques. Moreover, the roles of particle size, catalyst dosage, dye concentration, mixing conditions (e.g. ultrasound (US), stirring or shaking), and regeneration treatment were studied with the removal of cationic triphenylmethane dyes. Notably, the reduction process was also revealed as compared to nanoscale zero valent iron (nZVI), microscale iron power, and iron scurf. Furthermore, the reductive mechanism was exemplified with brilliant green. The results demonstrated that (1) the synergetic effect between US and s-Fe{sup 0} greatly enhanced the removal of dyes, (2) the dosage of preferred s-Fe{sup 0} (1–3 mm) particles was optimized as 30.0 g/L; (3) reuse cycles of s-Fe{sup 0} catalyst were enhanced with the assistance of diluted HCl solution; (4) the main degradation routes included the cleavage of conjugated structure reactions, N-de-ethylation reactions, hydroxylation reactions, the removal of benzene ring reactions, and opening ring reactions. Accordingly, the pretreatment of aqueous solution over s-Fe{sup 0} was hypothesized to achieve mainly through direct reduction reaction by electron transfer and indirect reductive reactions by the highly activated hydrogen atom. Additionally, decoration with noble metals was utilized to reveal the reaction mechanism.

Very low sound velocities in iron-rich (Mg,Fe)O: Implications for the core-mantle boundary region

International Nuclear Information System (INIS)

Wicks, J.K.; Jackson, J.M.; Sturhahn, W.

2010-01-01

The sound velocities of (Mg .16 Fe .84 )O have been measured to 121 GPa at ambient temperature using nuclear resonant inelastic x-ray scattering. The effect of electronic environment of the iron sites on the sound velocities were tracked in situ using synchrotron Moessbauer spectroscopy. We found the sound velocities of (Mg .16 Fe .84 )O to be much lower than those in other presumed mantle phases at similar conditions, most notably at very high pressures. Conservative estimates of the effect of temperature and dilution on aggregate sound velocities show that only a small amount of iron-rich (Mg,Fe)O can greatly reduce the average sound velocity of an assemblage. We propose that iron-rich (Mg,Fe)O be a source of ultra-low velocity zones. Other properties of this phase, such as enhanced density and dynamic stability, strongly support the presence of iron-rich (Mg,Fe)O in localized patches above the core-mantle boundary.

Evaluation of Antioxidant and Cytotoxicity Activities of Copper Ferrite (CuFe2O4 and Zinc Ferrite (ZnFe2O4 Nanoparticles Synthesized by Sol-Gel Self-Combustion Method

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Samikannu Kanagesan

2016-08-01

Full Text Available Spinel copper ferrite (CuFe2O4 and zinc ferrite (ZnFe2O4 nanoparticles were synthesized using a sol-gel self-combustion technique. The structural, functional, morphological and magnetic properties of the samples were investigated by Fourier transform infrared spectroscopy (FTIR, X-ray diffraction (XRD, Transmission electron microscopy (TEM and vibrating sample magnetometry (VSM. XRD patterns conform to the copper ferrite and zinc ferrite formation, and the average particle sizes were calculated by using a transmission electron microscope, the measured particle sizes being 56 nm for CuFe2O4 and 68 nm for ZnFe2O4. Both spinel ferrite nanoparticles exhibit ferromagnetic behavior with saturation magnetization of 31 emug−1 for copper ferrite (50.63 Am2/Kg and 28.8 Am2/Kg for zinc ferrite. Both synthesized ferrite nanoparticles were equally effective in scavenging 2,2-diphenyl-1-picrylhydrazyl hydrate (DPPH free radicals. ZnFe2O4 and CuFe2O4 nanoparticles showed 30.57% ± 1.0% and 28.69% ± 1.14% scavenging activity at 125 µg/mL concentrations. In vitro cytotoxicity study revealed higher concentrations (>125 µg/mL of ZnFe2O4 and CuFe2O4 with increased toxicity against MCF-7 cells, but were found to be non-toxic at lower concentrations suggesting their biocompatibility.

Flow-Injection Solid Phase Partial Least-Squares Spectrophotometric Simultaneous Determination of Iron, Nickel and Zinc

Directory of Open Access Journals (Sweden)

Teixeira Leonardo S. G.

2002-01-01

Full Text Available A PLS-2 multivariate calibration method has been developed for the simultaneous determination of iron, nickel and zinc in ternary mixtures by solid phase spectrophotometry associated with flow injection analysis. Fe(II, Ni(II and Zn(II form color complexes with 1-(2-thiazolylazo-2-naphthol (TAN, immobilized on a C18 bonded silica support, at pH 6.4. The proposed procedure is based on the different reaction/retention ratios of the studied ions on the solid support. Bilinear spectrophotometric data of the analytes, fixed in the solid support, were recorded in the 400-800 nm wavelength range as a function of time and a partial least squares (PLS-2 algorithm was used to predict results of synthetic samples. The calibration set employed was integrated by 8 ternary mixture standards and a blank solution. Mixtures containing 0.040 to 0.20 mg L-1, of each species, were successfully resolved, using 3 factors for each analyte and a restricted number of absorbance data obtained in the wavelength range from 560 to 650 nm.

Iron intake by rats using peroral administration of /sup 55/Fe-salts of phosphatidic acids

Energy Technology Data Exchange (ETDEWEB)

Rauch, P.; Kas, J. (Inst. of Chemical Technology, Prague (Czechoslovakia)); Tykva, R. (Ceskoslovenska Akademie Ved, Prague. Ustav Organicke Chemie a Biochemie)

1984-03-15

The utilization of /sup 55/Fe and its incorporation into rat organs was investigated after peroral administration of various salts of phosphatidic acids (PA). Iron of PA salts is utilized up to 58-94% comparing to /sup 55/Fe/sup 2 +/. The degree of iron utilization depends on the type of PA salts administered. 16 refs.

Iron, Magnesium, Vitamin D, and Zinc Deficiencies in Children Presenting with Symptoms of Attention-Deficit/Hyperactivity Disorder

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Amelia Villagomez

2014-09-01

Full Text Available Attention-Deficit/Hyperactivity Disorder (ADHD is a neurodevelopmental disorder increasing in prevalence. Although there is limited evidence to support treating ADHD with mineral/vitamin supplements, research does exist showing that patients with ADHD may have reduced levels of vitamin D, zinc, ferritin, and magnesium. These nutrients have important roles in neurologic function, including involvement in neurotransmitter synthesis. The aim of this paper is to discuss the role of each of these nutrients in the brain, the possible altered levels of these nutrients in patients with ADHD, possible reasons for a differential level in children with ADHD, and safety and effect of supplementation. With this knowledge, clinicians may choose in certain patients at high risk of deficiency, to screen for possible deficiencies of magnesium, vitamin D, zinc, and iron by checking RBC-magnesium, 25-OH vitamin D, serum/plasma zinc, and ferritin. Although children with ADHD may be more likely to have lower levels of vitamin D, zinc, magnesium, and iron, it cannot be stated that these lower levels caused ADHD. However, supplementing areas of deficiency may be a safe and justified intervention.

Impact on the Fe redox cycling of organic ligands released by Synechococcus PCC 7002, under different iron fertilization scenarios. Modeling approach

Science.gov (United States)

Samperio-Ramos, Guillermo; González-Dávila, Melchor; Santana-Casiano, J. Magdalena

2018-06-01

The kinetics of Fe redox transformations are of crucial importance in determining the bioavailability of iron, due to inorganic Fe(II) and Fe weakly organic complexes being the most easily assimilated species by phytoplankton. The role played by the natural organic ligands excreted by the cyanobacteria Synecococcus PCC 7002 on the iron redox chemistry was studied at different stages of growth, considering changes in the organic exudation of the cyanobacteria, associated with growth under two different scenarios of iron availability. The oxidation/reduction processes of iron were studied at nanomolar levels and under different physicochemical conditions of pH (7.2- 8.2), temperature (5- 35 °C) and salinity (10- 37). The presence of natural organic exudates of Synechococcus affected the redox behavior of iron. A pH-dependent and photo-induced Fe(III) reduction process was detected in the presence of exudates produced under Fe-Low conditions. Photolytic reactions also modified the reactivity of those exudates with respect to Fe(II), increasing its lifetime in seawater. Without light mediated processes, organic ligands excreted under iron deficient conditions intensified the Fe(II) oxidation at pH redox constants between iron and the major ligands present in solution. Two organic type ligands for the exudates of Synechococcus PCC 7002, with different iron-chelation properties were included in the model. The Fe(II) speciation was radically affected when organic ligands were considered. The individual contributions to the overall Fe(II) oxidation rate demonstrated that these organic ligands played a key role in the oxidation process, although their contributions were dependent on the prescribed iron conditions. The study, therefore, suggests that the variability in the composition and nature of organic exudates released, due to iron availability conditions, might determine the redox behaviour of iron in seawater.

Synthesis of novel magnetic iron metal-silica (Fe-SBA-15) and magnetite-silica (Fe{sub 3}O{sub 4}-SBA-15) nanocomposites with a high iron content using temperature-programed reduction

Energy Technology Data Exchange (ETDEWEB)

Yiu, H H P [Department of Chemistry, University of Liverpool, Liverpool, Merseyside L69 7ZD (United Kingdom); Keane, M A [Chemical Engineering, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom); Lethbridge, Z A D [Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL (United Kingdom); Lees, M R [Department of Physics, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL (United Kingdom); Haj, A J El; Dobson, J [Institute of Science and Technology in Medicine, Keele University, Thornburrow Drive, Hartshill, Stoke-on-Trent ST4 7QB (United Kingdom)], E-mail: j.p.dobson@keele.ac.uk

2008-06-25

Magnetic iron metal-silica and magnetite-silica nanocomposites have been prepared via temperature-programed reduction (TPR) of an iron oxide-SBA-15 (SBA: Santa Barbara Amorphous) composite. TPR of the starting SBA-15 supported Fe{sub 2}O{sub 3} generated Fe{sub 3}O{sub 4} and FeO as stepwise intermediates in the ultimate formation of Fe-SBA-15. The composite materials have been characterized by means of x-ray diffraction, high resolution transmission electron microscopy and SQUID (superconducting quantum interference device) magnetometry. The Fe oxide and metal components form a core, as nanoscale particles, that is entrapped in the SBA-15 pore network. Fe{sub 3}O{sub 4}-SBA-15 and Fe-SBA-15 exhibited superparamagnetic properties with a total magnetization value of 17 emu g{sup -1}. The magnetite-silica composite (at an Fe{sub 3}O{sub 4} loading of 30% w/w) delivered a magnetization that exceeded values reported in the literature or obtained with commercial samples. Due to the high pore volume of the mesoporous template, the magnetite content can be increased to 83% w/w with a further enhancement of magnetization.

Trace Element Status (Zinc, Copper, Selenium, Iron, Manganese) in Patients with Long-Term Home Parenteral Nutrition.

Science.gov (United States)

Dastych, Milan; Šenkyřík, Michal; Dastych, Milan; Novák, František; Wohl, Petr; Maňák, Jan; Kohout, Pavel

2016-01-01

The objective of the present study was to determine concentrations of zinc (Zn), copper (Cu), iron (Fe), selenium (Se) in blood plasma and manganese (Mn) in the whole blood in patients with long-term home parenteral nutrition (HPN) in comparison to the control group. We examined 68 patients (16 men and 52 women) aged from 28 to 68 years on a long-term HPN lasting from 4 to 96 months. The short bowel syndrome was an indication for HPN. The daily doses of Zn, Cu, Fe, Se and Mn in the last 3 months were determined. No significant differences in blood plasma were found for Zn, Cu and Fe in patients with HPN and in the control group (p > 0.05). The concentration of Mn in whole blood was significantly increased in HPN patients (p < 0.0001), while Se concentration in these patients was significantly decreased (p < 0.005). The concentration of Mn in the whole blood of 16 patients with cholestasis was significantly increased compared to the patients without cholestasis (p < 0.001). The Cu concentration was increased with no statistical significance. In long-term HPN, the status of trace elements in the patients has to be continually monitored and the daily substitution doses of these elements have to be flexibly adjusted. Dosing schedule needs to be adjusted especially in cases of cholestatic hepatopathy. A discussion about the optimal daily dose of Mn in patients on HPN is appropriate. For clinical practice, the availability of a substitution mixture of trace elements lacking Mn would be advantageous. © 2016 S. Karger AG, Basel.

Probiotics lactobacillus reuteri DSM 17938 and lactobacillus casei CRL 431 modestly increase growth, but non iron and zinc status, among Indonesian children aged 1-6 years

NARCIS (Netherlands)

Agustina, R.; Bovee-Oudenhoven, I.M.J.; Lukito, W.; Fahmida, U.; Rest, van de O.; Zimmermann, M.B.; Firmansyah, A.; Wulanti, R.; Albers, R.; Heuvel, van den E.G.H.M.; Kok, F.J.

2013-01-01

Probiotics and milk calcium may increase resistance to intestinal infection, but their effect on growth and iron and zinc status of Indonesian children is uncertain. We investigated the hypotheses that cow milk with added probiotics would improve growth and iron and zinc status of Indonesian

Synthesis and photocatalytic application of α-Fe2O3/ZnO fine particles prepared by two-step chemical method

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Patij Shah

2013-06-01

Full Text Available Composite iron oxide-Zinc oxide (α-Fe2O3/ZnO was synthesized by two-step method: in the first one step uniform α-Fe2O3 particles were prepared through a hydrolysis process of ferric chloride at 80 °C. In the second step, the ZnO particles were included in the α-Fe2O3 particles by a zinc acetate [Zn(Ac2·2H2O] assisted hydrothermal method at low temperature (90°C±C. The α-Fe2O3 and ZnO phases were identified by XRD, energy dispersive X-ray analysis (EDX. The photoreactivities of α-Fe2O3/ZnO nanoparticles under UV irradiation were quantified by the degradation of formaldehyde.

Preparation of cobalt-zinc ferrite (Co0.8Zn0.2Fe2O4) nanopowder via combustion method and investigation of its magnetic properties

International Nuclear Information System (INIS)

Yousefi, M.H.; Manouchehri, S.; Arab, A.; Mozaffari, M.; Amiri, Gh. R.; Amighian, J.

2010-01-01

Research highlights: → Cobalt-zinc ferrite was prepared by combustion method. → Properties of the sample were characterized by several techniques. → Curie temperature was determined to be 350 o C. -- Abstract: Cobalt-zinc ferrite (Co 0.8 Zn 0.2 Fe 2 O 4 ) was prepared by combustion method, using cobalt, zinc and iron nitrates. The crystallinity of the as-burnt powder was developed by annealing at 700 o C. Crystalline phase was investigated by XRD. Using Williamson-Hall method, the average crystallite sizes for nanoparticles were determined to be about 27 nm before and 37 nm after annealing, and residual stresses for annealed particles were omitted. The morphology of the annealed sample was investigated by TEM and the mean particle size was determined to be about 30 nm. The final stoichiometry of the sample after annealing showed good agreement with the initial stoichiometry using atomic absorption spectrometry. Magnetic properties of the annealed sample such as saturation magnetization, remanence magnetization, and coercivity measured at room temperature were 70 emu/g, 14 emu/g, and 270 Oe, respectively. The Curie temperature of the sample was determined to be 350 o C using AC-susceptibility technique.

Electrochemical impedance spectroscopy and zero resistance ammeters (ZRA) as tools for studying the behaviour of zinc-rich inorganic coatings

International Nuclear Information System (INIS)

Novoa, X.R.; Izquierdo, M.; Merino, P.; Espada, L.

1989-01-01

Impedance spectra obtained from zinc-rich inorganic coatings after one year of atmospheric exposure, have been interpreted on the basis of the study of the galvanic couple Zn/Fe, using a potentiostat combined with two ZRA. The area ratio of Zn/Fe is one of the factors conditioning the cathodic protection of iron. When this ratio is locally 1:1 or lower, corrosion spots are detected on iron and the overall impedance spectra shows a 'flattened' shape at low frequencies. The type of atmosphere determines the durability and evolution of the coating's protection mechanism. (author) 9 refs., 13 figs

Reactions of laser-ablated iron atoms and cations with carbon monoxide: Infrared spectra of FeCO+, Fe(CO)2+, Fe(CO)x, and Fe(CO)x- (x=1-4) in solid neon

Science.gov (United States)

Zhou, Mingfei; Andrews, Lester

1999-06-01

Laser-ablated iron atoms, cations, and electrons have been reacted with CO molecules during condensation in excess neon. The FeCO molecule is observed at 1933.7 cm-1 in solid neon. Based on isotopic shifts and density functional calculations, the FeCO molecule has the same 3Σ- ground state in solid neon that has been observed at 1946.5 cm-1 in a recent high resolution gas phase investigation [Tanaka et al., J. Chem. Phys. 106, 2118 (1997)]. The C-O stretching vibration of the Fe(CO)2 molecule is observed at 1917.1 cm-1 in solid neon, which is in excellent agreement with the 1928.2 cm-1 gas phase value for the linear molecule. Anions and cations are also produced and trapped, absorptions at 1782.0, 1732.9, 1794.5, and 1859.7 cm-1 are assigned to the linear FeCO-, Fe(CO)2-, trigonal planar Fe(CO)3-, and C3v Fe(CO)4- anions, respectively, and 2123.0, 2134.0 cm-1 absorptions to the linear FeCO+ and Fe(CO)2+ cations. Doping these experiments with CCl4 virtually eliminates the anion absorptions and markedly increases the cation absorptions, which confirms the charge identifications. Higher iron carbonyl Fe(CO)3, Fe(CO)4, and Fe(CO)5 absorptions are produced on photolysis.

Isotope-aided studies of the bioavailability of iron and zinc from human diets consumed in Poland

International Nuclear Information System (INIS)

Rafalski, H.; Switoniak, T.

1994-01-01

The bioavailability of food iron is affected by a number of physiological and dietary variables and it should be checked for the population living in natural conditions. The primary purpose of this study was to measure in volunteers iron absorption after oral administration of a wheat roll enriched with 15 mg of Fe as FeSO 4· 7H 2 O and 20 μCi of 59 Fe. For assessment of iron absorption whole body counting was used. The secondary purpose was to relate the available iron to iron stores, anthropometric indices, bleeding days and dietary variables. Thirteen female and 7 male healthy subjects aged between 19 and 47 years were observed. Hematological measurements on blood: serum ferritin (SF), serum iron (SI), total iron binding capacity (TIBC), transferrin (ST), transferrin saturation (TS), hemoglobin (Hb), hematocrit (Hct), red blood cell (RBC), mean corpuscular volume (MCV) were made. The subjects were examined by a specialist in internal medicine. Their 24-hour recall food intake was performed by questionnaire. The findings concerning the purposes of the study may be summarized as follows: 1) mean absorbed iron was 1.6 ± 1.2 mg for women, and 0.5±0.2 mg for men; 2) iron stores evaluated from SF were in women 2.6± 1.7 mg/kg body weight and in men 10.4±5.4 mg/kg; 3) blood indices proved iron deficiency anemia in 1 woman, Hb = 9.2 g/dL, SF = 1.8 μg/L, TS = 6%; in 4 women deficient iron stores were observed, Hb > 12g/dL, SF < 12 mg/L; 8 women and 7 men were normal; 4) in women the absorbed iron related inversely to SF (-0.61) and iron stores (-0.61); 5) the iron stores related to the sum of four skinfolds in women (0.55) and in men (0.80), in women it related to body weight (0.77) too; 6) in women the absorbed iron related to bleeding days (0.69); 7) in women ascorbic acid consumption related to iron store indices; SF, SI and TS. (author). 2 figs, 3 tabs

One-step synthesis for FeBTC-MOF/iron oxide composite

Energy Technology Data Exchange (ETDEWEB)

Nascimento, R.F.F. do; Gentil, G.; Junior, S.A.; Azevedo, W.M. de; Rodrigues, A.R.; Campello, S.L. [Universidade Federal de Pernambuco (UFPE), PE (Brazil)

2016-07-01

Full text: In this work we present the assisted ultrasonic radiation synthesis for f Fe(BTC) (BTC = 1,3,5-benzenetricarboxilic acid) metal organic framework preparation. By definition Metal-organic frameworks (MOFs) belongs to a class of material prepared by the combination of metal ions and organic linkers to form a tridimensional framework which presents defined characteristics like crystallinity, high porosity and the presence of strong metal-ligand interaction. In the last decades the MOFs materials have received considerable attention not only due to scientific interest, but also because of their high potential for applications in several technological areas such as in gas storage, catalysis and drug delivery [1]. Among several Metal-organic frameworks (MOFs) the Fe-BTC structure seems to be one of promising materials, mainly due to their chemical and thermal stability, presents biocompatibility, can be used as drug delivery and as a contrast agent for magnetic resonance. Its functionalization has been reported in the literature by several works where the methods consist to mix the iron oxide Fe3O4 nanoparticles, in the solution contained the MOF'S precursor and the synthesis is prepared by solvothermal method. Typically, it has core-shell Fe3O4@MOF structures and exhibit magnetic properties. Our experimental technique proposed for the synthesis of the composite consists to use iron powder (?-Fe) as a target material dispersed in a solution of DMF/H2O (1:1) containing benzene 1,3,5 tricarboxilic acid and NaNO3. The synthesis was performed using a Ultrasound equipment model GEX500 500 W operating at 80 kHz, pulse 1s intervals for 60 min. The x-ray diffraction patterns and SEM measurements shown that the obtained materials are similar to those found in the literature and presents a rods likes morphology. The BET analysis indicate that the surface area is 1257 m²g-1 and pore volume 1.4 cm³g-1. Also the magnetic measurements indicates a paramagnetic

Effects of Fe-chelate and iron oxide nanoparticles on some of the physiological characteristics of alfalfa (Medicago sativa L.

Directory of Open Access Journals (Sweden)

Mehri Askary

2018-06-01

Full Text Available Introduction Iron is an essential micronutrient for plant growth that plays an important role in plant metabolism. Iron deficiency is an abiotic stress that is often found in plants grown in calcareous and alkaline soils. The solubility of Fe+3 decreases dramatically with increasing pH. 30% of the arable land worldwide consists of calcareous and alkaline soils. Common iron fertilizers used to reduce deficiency syndromes contain iron(II sulfate heptahydrate (FeSO4.7H2O or iron chelates. Iron chelate (for example Fe-EDTA is absorbed by plants, which however depends on soil conditions especially soil pH. Nowadays , nano-Fe fertilizer can be used as a rich source of iron for plants ,because it gradually releases Fe in a wide pH range (pH 3– 11. Nanofertilizer usage leads to increase element efficiency, reduce soil toxicity and negative effects caused by the excessive consumption of chemical fertilizers and reduce the fertilizer’ s application . This research was carried out to determine the suitable type of iron fertilizer and to evaluate the effects of different concentrations of nano-Fe fertilizer on Medicago sativa Materials and methods In order to investigate the effects of Fe-deficiency and different levels of Fe2O3 nanoparticles compared to Fe-EDTA on leaf growth, photosynthetic pigments and antioxidative activity of alfalfa (Medicago sativa cv.Hamadani, an experiment was conducted based on completely randomized design with three replications in Arak University during 2015. After germination of sterilized seeds of alfalfa, 1-day seedlings were cultured in plastic vases contains perlite. Plants were maintained under 25/18°C day/night temperatures with 12-hr photoperiod. Irrigation was done weekly with 100ml complete Hoagland solution (containing iron chelate (Fe-EDTA for control plants or 100ml Hoagland solution without iron chelate and containing different concentrations of ironoxide nanoparticles (0, 5, 10, 20 and 25µM. Plants

Optical and structural properties of FeSe2 thin films obtained by selenization of sprayed amorphous iron oxide films

International Nuclear Information System (INIS)

Ouertani, B.; Ouerfelli, J.; Saadoun, M.; Zribi, M.; Rabha, M.Ben; Bessais, B.; Ezzaouia, H.

2006-01-01

We report in this work the optical and structural properties of iron diselenide films (FeSe 2 ) obtained by selenization under vacuum of amorphous iron oxide films predeposited by spray pyrolysis. The structure of the FeSe 2 films was investigated by scanning electron microscopy (SEM), microprobe analyses, atomic force microscopy (AFM) and X-ray diffraction (XRD). XRD and micro-probe analyses showed that FeSe 2 as well as FeSe 2-x phases begin to appear at a selenization temperature of 500 deg. C. As the selenization temperature rises, the iron diselenide films become more stoichiometric with a dominance of the FeSe 2 phase. At 550 deg. C, a single FeSe 2 phase having good crystallinity was obtained. At 600 deg. C, two phases were detected: the major one corresponds to Fe 3 O 4 , and the minor one to FeSe 2 . SEM surface views show that FeSe 2 films have granular structure with small spherical crystallites. However, layered and clustered FeSe 2 films were found, respectively, at 550 deg. C and 600 deg. C. Absorption measurements show that iron diselenide films have a direct and an indirect gaps of about 1.03 eV and 0.3 eV, which were suggested to be due to the stoichiometric FeSe 2 phase and to a Fe-rich non-stoichiometric phase, respectively

Effects of Tungsten Addition on the Microstructure and Corrosion Resistance of Fe-3.5B Alloy in Liquid Zinc

Directory of Open Access Journals (Sweden)

Xin Liu

2017-04-01

Full Text Available The effects of tungsten addition on the microstructure and corrosion resistance of Fe-3.5B alloys in a liquid zinc bath at 520 °C were investigated by means of scanning electron microscopy, X-ray diffraction and electron probe micro-analysis. The microstructure evolution in different alloys is analyzed and discussed using an extrapolated Fe-B-W ternary phase diagram. Experimental results show that there are three kinds of borides, the reticular (Fe, W2B, the rod-like (Fe, W3B and flower-like FeWB. The addition of tungsten can refine the microstructure and improve the stability of the reticular borides. Besides, it is beneficial to the formation of the metastable (Fe, W3B phase. The resultant Fe-3.5B-11W (wt % alloy possesses excellent corrosion resistance to liquid zinc. When tungsten content exceeds 11 wt %, the formed flower-like FeWB phase destroys the integrity of the reticular borides and results in the deterioration of the corrosion resistance. Also, the corrosion failure resulting from the spalling of borides due to the initiation of micro-cracks in the grain boundary of borides is discussed in this paper.

Comparative studies on acid leaching of zinc waste materials

Science.gov (United States)

Rudnik, Ewa; Włoch, Grzegorz; Szatan, Leszek

2017-11-01

Three industrial waste materials were characterized in terms of their elemental and phase compositions, leaching behaviour in 10% sulfuric acid solution as well as leaching thermal effects. Slag from melting of mixed metallic scrap contained about 50% Zn and 10% Pb. It consisted mainly of various oxides and oxy-chlorides of metals. Zinc spray metallizing dust contained about 77% Zn in form of zinc and/or zinc-iron oxides, zinc metal and Zn-Fe intermetallic. Zinc ash from hot dip galvanizing was a mixture of zinc oxide, metallic zinc and zinc hydroxide chloride and contained about 80% Zn. Dissolution efficiency of zinc from the first material was 80% (independently on the solid to liquid ratio, 50-150 kg/m3), while decrease of the efficacy from 80% to 60% with increased solid to liquid ratio for the two remaining materials was observed. Both increase in the temperature (20 °C to 35 °C) and agitation rate (300 rpm to 900 rpm) did not improve seriously the leaching results. In all cases, transfer of zinc ions to the leachate was accompanied by different levels of solution contamination, depending on the type of the waste. Leaching of the materials was exothermic with the similar reaction heats for two high oxide-type products (slag, zinc ash) and higher values for the spray metallizing dust.

Studies on iron absorption and retention in malnourished Indian subjects, using Fe-59 and whole-body counting

International Nuclear Information System (INIS)

Gopalan, C.; Srikantia, S.G.

1975-12-01

The gastrointestinal absorption of iron under various conditions in representatives of the Indian population, and several related matters, have been investigated. Percentage absorption was determined by whole-body counting of 59Fe, or by measuring the concentration of 55Fe in the blood, at about two weeks after administration of the respective tracer. It was confirmed or established that: (1) food or supplemental iron, if available at all, tends to be absorbed from the intestines as if present there in one of two alternative pools: heme and non heme; (2) 30%-50% of iron measured chemically in Indian foods appears to be in an unavailable form, for example as a contaminant in adventitiously present dust; (3) fortification of the diet with iron may be feasible by adding FePO 4 + 2 molar NaHSO 4 to common salt under suitable conditions; (4) monkeys appear to be sufficiently similar to humans in their iron absorption characteristics that they may be the best available non-human model for preliminary experimental investigations of iron absorption; and (5) a promising preparative method for liquid scintillation counting of 55Fe present in blood is to extract it into toluene in the presence of di (2-ethyl-hexyl) phosphate (HDEHP)

Transformation impacts of dissolved and solid phase Fe(II) on trichloroethylene (TCE) reduction in an iron-reducing bacteria (IRB) mixed column system: a mathematical model.

Science.gov (United States)

Bae, Yeunook; Kim, Dooil; Cho, Hyun-Hee; Singhal, Naresh; Park, Jae-Woo

2012-12-01

In this research, we conducted trichloroethylene (TCE) reduction in a column filled with iron and iron-reducing bacteria (IRB) and developed a mathematical model to investigate the critical reactions between active species in iron/IRB/contaminant systems. The formation of ferrous iron (Fe(II)) in this system with IRB and zero-valent iron (ZVI, Fe(0)) coated with a ferric iron (Fe(III)) crust significantly affected TCE reduction and IRB respiration in various ways. This study presents a new framework for transformation property and reducing ability of both dissolved (Fe(II)(dissolved)) and solid form ferrous iron (Fe(II)(solid)). Results showed that TCE reduction was strongly depressed by Fe(II)(solid) rather than by other inhibitors (e.g., Fe(III) and lactate), suggesting that Fe(II)(solid) might reduce IRB activation due to attachment to IRB cells. Newly exposed Fe(0) from the released Fe(II)(dissolved) was a strong contributor to TCE reduction compared to Fe(II)(solid). In addition, our research confirmed that less Fe(II)(solid) production strongly supported long-term TCE reduction because it may create an easier TCE approach to Fe(0) or increase IRB growth. Our findings will aid the understanding of the contributions of iron media (e.g., Fe(II)(solid), Fe(II)(dissolved), Fe(III), and Fe(0)) to IRB for decontamination in natural groundwater systems. Copyright © 2012 Elsevier Ltd. All rights reserved.

Photocatalytic segmented nanowires and single-step iron oxide nanotube synthesis: Templated electrodeposition as all-round tool

NARCIS (Netherlands)

Maas, M.G.; Rodijk, E.J.B.; Maijenburg, A.W.; ten Elshof, Johan E.; Blank, David H.A.; Nielsch, K.; Fontcuberta i Morral, A.; Holt, J.K.; Thomson, C.V.

2010-01-01

Templated electrodeposition was used to synthesize silver-zinc oxide nanowires and iron oxide (Fe2O3) nanotubes in polycarbonate track etched (PCTE) membranes. Metal/oxide segmented nanowires were made to produce hydrogen gas from a water/methanol mixture under ultraviolet irradiation. It was

Effects of metformin treatment on Iron, Zinc and Copper status concentration in the serum of female rats with induced polycystic ovary syndrome

Directory of Open Access Journals (Sweden)

Muhsin S. G. Al-Moziel

2013-07-01

Full Text Available This study conducted to investigate the effects of metformin drug on serum Iron, Zinc and Copper concentration in Estradiol Valerate(EV induced polycystic ovary syndrome(PCOS in virgin rats. Thirty virgin rats were randomly allotted to constitute Normal control (NC-I group and induced polycystic ovary (PCO-I and PCO-II groups having 10 rats in each group. Rats from NC-I group were administered intramuscularly with 0.2 ml of corn oil whereas polycystic ovary was induced in rats from PCO-I and PCO-II groups by administering single intra-muscular injection of estradiol Valerate 4mg/rat. The rats from PCO-I and PCO-II groups were left for 60 days for development of polycystic ovary syndrome. Animals from PCO-I group were then administered with 0.2 ml normal saline as oral gavage for 15 days, these animals were kept as PCO control group animals whereas those from PCO-II groups received metformin (50mg/kg B.wt as oral gavage for 15 days, these animals served as metformin treated PCO group animals. All the rats were thereafter sacrificed for collecting blood from inferior vena-cava. Serum samples from each rat were assessed for iron, zinc and copper status in each experimental group. The results revealed a significant (p≤0.05 increase in serum Fe and Zn and a significant (p≤0.05 decrease in serum Cu concentration in PCO group 1 compared with control non-treated group. The PCO group2 treated with metformin showed a significant (p≤0.05 decrease in serum Fe concentration as compared with those in animals from group NC-I and PCO-I. While, no significant differences were found in serum Zn concentration between all treated groups. On the other hand, a significant (p≤0.05 increase in serum Cu concentration appeared in metformin treated group compared with PCO group 1 which appears significant decrease compared with control group.

Content of zinc, iron, calcium and their absorption inhibitors in foods commonly consumed in Ethiopia

NARCIS (Netherlands)

Umeta, M.; West, C.E.; Fufa, H.

2005-01-01

The zinc, iron, calcium, phosphorus, phytate, tannin and moisture content of 36 foods consumed in rural Ethiopia were analysed. The foods analysed included those based on cereals, starchy tubers and roots, and legumes and vegetables as well as some fruits. Although many foods were relatively rich in

Association of Increased Grain Iron and Zinc Concentrations with Agro-morphological Traits of Biofortified Rice

Directory of Open Access Journals (Sweden)

Laura Tatiana Moreno-Moyano

2016-09-01

Full Text Available Biofortification of rice (Oryza sativa L. with micronutrients is widely recognized as a sustainable strategy to alleviate human iron (Fe and zinc (Zn deficiencies in developing countries where rice is the staple food. Constitutive overexpression of the rice nicotianamine synthase (OsNAS genes has been successfully implemented to increase Fe and Zn concentrations in unpolished and polished rice grain. Intensive research is now needed to couple this high-micronutrient trait with high grain yields. We investigated associations of increased grain Fe and Zn concentrations with agro-morphological traits of backcross twice second filial (BC2F2 transgenic progeny carrying OsNAS1 or OsNAS2 overexpression constructs under indica/japonica and japonica/japonica genetic backgrounds. Thirteen agro-morphological traits were evaluated in BC2F2 transgenic progeny grown under hydroponic conditions. Concentrations of 8 mineral nutrients (Fe, Zn, copper, manganese, calcium, magnesium, potassium and phosphorus in roots, stems/sheaths, non-flag leaves, flag leaves, panicles and grain were also determined. A distance-based linear model (DistLM was utilized to extract plant tissue nutrient predictors accounting for the largest variation in agro-morphological traits differing between transgenic and non-transgenic progeny. Overall, the BC2F2 transgenic progeny contained up to 148% higher Fe and 336% higher Zn concentrations in unpolished grain compared to non-transgenic progeny. However, unpolished grain concentrations surpassing 23 µg Fe g-1 and 40 µg Zn g-1 in BC2F2 indica/japonica progeny, and 36 µg Fe g-1 and 56 µg Zn g1 in BC2F2 japonica/japonica progeny, were associated with significant reductions in grain yield. DistLM analyses identified grain-Zn and panicle-magnesium as the primary nutrient predictors associated with grain yield reductions in the indica/japonica and japonica/japonica progeny, respectively. We subsequently produced polished grain from high

Bimetallic Porous Iron (pFe) Materials for Remediation/Removal of Tc from Aqueous Systems

Energy Technology Data Exchange (ETDEWEB)

Li, D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2017-09-29

Remediation of Tc remains an unresolved challenge at SRS and other DOE sites. The objective of this project was to develop novel bimetallic porous iron (pFe) materials for Tc removal from aqueous systems. We showed that the pFe is much more effective in removing TcO₄ - (×30) and ReO₄ - (×8) from artificial groundwater than granular iron. Tc K-edge XANES spectroscopy indicated that Tc speciation on the pFe was 18% adsorbed TcO₄ -, 28% Tc(IV) in Tc dioxide and 54% Tc(IV) into the structure of Fe hydroxide. A variety of catalytic metal nanoparticles (i.e., Ni, Cu, Zn, Ag, Sn and Pd) were successfully deposited on the pFe using scalable chemical reduction methods. The Zn-pFe was outstanding among the six bimetallic pFe materials, with a capacity increase of >100% for TcO₄ - removal and of 50% for ReO₄ - removal, compared to the pFe. These results provide a highly applicable platform for solving critical DOE and industrial needs related to nuclear environmental stewardship and nuclear power production.

Influence of FeEDDS, FeEDTA, FeDTPA, FeEDDHA, and FeSO4 on Marigold Growth and Nutrition, and Substrate and Runoff Chemistry

Science.gov (United States)

Objectives of the study were to determine effects of Fe source on plant growth, plant nutrition, substrate chemistry and runoff chemistry. Iron source (FS) treatments consisted of Fe-aminopolycarboxylic acid (APCA) complexones iron ethylenediaminetetraacetic acid (FeEDTA), iron [S, S']-ethylenediam...

Evaluation of iron, zinc, copper, manganese and selenium in oral hospital diets.

OpenAIRE

Moreira, Daniele Caroline Faria; Sá, Júlia Sommerlatte Manzoli de; Cerqueira, Isabel B.; Oliveira, Ana P. F. de; Morgano, Marcelo Antonio; Quintaes, Késia Diego

2013-01-01

Background & aims: Many trace elements are nutrients essential to humans, acting in the metabolism as constituents or as enzymatic co-factors. The iron, zinc, copper, manganese and selenium contents of hospital diets (regular, blend and soft) and of oral food complement (OFC) were determined, evaluating the adequacy of each element in relation to the nutritional recommendations (DRIs) and the percent contribution alone and with OFC. Methods: Duplicate samples were taken of six daily meals ...

Chemical evaluation of HBED/Fe(3+) and the novel HJB/Fe(3+) chelates as fertilizers to alleviate iron chlorosis.

Science.gov (United States)

López-Rayo, Sandra; Hernández, Diana; Lucena, Juan J

2009-09-23

Iron chelates such as ethylenediamine-N,N'-bis(2-hydroxyphenylacetic) acid (o,o-EDDHA) and their analogues are the most efficient soil fertilizers to treat iron chlorosis in plants growing in calcareous soil. A new chelating agent, HJB (N,N'-bis(2-hydroxy-5-methylphenyl)ethylendiamine-N,N'-diacetic acid) may be an alternative to o,o-EDDHA since its synthesis yields a purer product, but its chemical behavior and efficiency as chlorosis corrector should be evaluated. In this research, a known analogous HBED (N,N'-bis(2-hydroxyphenyl)ethylendiamine-N,N'-diacetic acid) has also been considered. First, an ion-pair high performance liquid chromatography (HPLC) method has been tested for the HJB/Fe(3+) and HBED/Fe(3+) determination. The ability of HJB and HBED to maintain Fe in solution has been compared with respect to o,o-EDDHA. Theoretical modelization for HBED and HJB in agronomic conditions has been done after the determination of the protonation and Ca(II), Mg(II), Fe(III), and Cu(II) stability constants for HJB. Also, batch interaction experiments with soils and soil materials have been conducted. According to our results, HJB/Fe(3+) and HBED/Fe(3+) present high stability, even when competing cations (Cu(2+), Ca(2+)) are present, and have low reactivity with soils and soil components. The chelating agent HJB dissolves a higher amount of Fe than o,o-EDDHA, and it seems as effective as o,o-EDDHA in keeping Fe in solution. These results indicate that these chelates may be very efficient products to correct Fe chlorosis, and additional plant experiments should demonstrate plants' ability to assimilate Fe from HJB/Fe(3+) and HBED/Fe(3+).

Effectiveness of Iron Ethylenediamine-N,N′-bis(hydroxyphenylacetic) Acid (o,o-EDDHA/Fe3+) Formulations with Different Ratios of Meso and d,l-Racemic Isomers as Iron Fertilizers

OpenAIRE

Alcañiz Lucas, Sara; Jordá Guijarro, Juana Dolores; Cerdán, Mar

2017-01-01

Two o,o-EDDHA/Fe3+ formulations (meso, 93.5% w/w of meso isomer; and d,l-racemic, 91.3% w/w of d,l-racemic mixture) were prepared, and their efficacy to avoid or to relieve iron deficiency in Fe-sufficient and Fe-deficient tomato plants grown on hydroponic solution was compared with that of the current o,o-EDDHA/Fe3+ formulations (50% of meso and d,l-racemic isomers). The effectiveness of the three o,o-EDDHA/Fe3+ formulations was different depending on the iron nutritional status of plants. T...

A Study on Zinc-Iron Alloy Electrodeposition from a Chloride Electrolyte

DEFF Research Database (Denmark)

Jensen, Jens Dahl

1998-01-01

The electrodeposition of zinc-iron alloys from a chloride-based electrolyte has been studied using electrochemical polarisation techniques, Auger Electron Spectroscopy (AES), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Analysis (EDXA) and Computer Assisted Pulse Plating (CAPP...... this system ideal for production of compositional modulated alloy (CMA) electrodeposits. Chloride content, pH and agitation of the electrolyte have been observed to have a strong influence on the reaction at the cathode surface, just as the use of pulse reversal current during electrodeposition. A theory...

Bacteria attenuation by iron electrocoagulation governed by interactions between bacterial phosphate groups and Fe(III) precipitates

NARCIS (Netherlands)

Delaire, Caroline; van Genuchten, Case M.; Amrose, Susan E.; Gadgil, Ashok J.

2016-01-01

Iron electrocoagulation (Fe-EC) is a low-cost process in which Fe(II) generated from an Fe(0) anode reacts with dissolved O2 to form (1) Fe(III) precipitates with an affinity for bacterial cell walls and (2) bactericidal reactive oxidants. Previous work suggests that Fe-EC is a promising treatment

Wet-chemical synthesis of nanoscale iron boride, XAFS analysis and crystallisation to α-FeB.

Science.gov (United States)

Rades, Steffi; Kornowski, Andreas; Weller, Horst; Albert, Barbara

2011-06-20

The reaction of lithium tetrahydridoborate and iron bromide in high boiling ether as reaction medium produces an ultrafine, pyrophoric and magnetic precipitate. X-ray and electron diffraction proved the product to be amorphous. According to X-ray absorption fine structure spectroscopy (XAFS) the precipitate has FeB structure up to nearly two coordination spheres around an iron absorber atom. Transmission electron microscopy (TEM) confirms the ultrafine powder to be nanoscale. Subsequent annealing at 450 °C causes the atoms to arrange in a more distinct FeB structure, and further thermal treatment to 1050 °C extends the local structure to the α-modification of FeB. Between 1050 °C and 1500 °C α-FeB is transformed into β-FeB. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Identification of Spinel Iron Oxide Nanoparticles by 57Fe NMR

Directory of Open Access Journals (Sweden)

SangGap Lee

2011-12-01

Full Text Available We have synthesized and studied monodisperse iron oxide nanoparticles of smaller than 10 nm to identify between the two spinel phases, magnetite and maghemite. It is shown that 57Fe NMR spectroscopy is a promising tool for distinguishing between the two phases.

Addition of iron for the removal of the {beta}-AlFeSi intermetallic by refining of {alpha}-AlFeSi phase in an Al-7.5Si-3.6Cu alloy

Energy Technology Data Exchange (ETDEWEB)

Belmares-Perales, S. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon (Mexico); Zaldivar-Cadena, A.A., E-mail: azaldiva70@hotmail.com [Facultad de Ingenieria Civil, Departamento de Ecomateriales y Energia, Instituto de Ingenieria Civil, Av. Fidel Velasquez and Av. Universidad S/N, Cd. Universitaria, San Nicolas de los Garza, N.L. 66450 (Mexico)

2010-10-25

Addition of iron into the molten metal for the removal of the {beta}-AlFeSi intermetallic by refining of {alpha}-AlFeSi phase has been studied. Solidification conditions and composition determine the final microstructure and mechanical properties of a casting piece. It is known that increasing the iron content will produce an increasing of the {alpha}-AlFeSi and {beta}-AlFeSi phases. This phenomenon was confirmed with calculations made by Thermo-Calc{sup TM} software and validated with experimental results, however, the technique of iron addition in this study plays an important role on the solidification kinetics of these iron phases because the refining of {alpha}-AlFeSi and removal of {beta}-AlFeSi phases can be improved. Final results showed an improvement in mechanical properties by removal and refining of {beta}-AlFeSi and {alpha}-AlFeSi phases, respectively. This study shows a new method of removal of {beta}-AlFeSi that could be adopted in the aluminum smelting industry in aluminum alloys with a low cooling rate with a secondary dendritic spacing of about 37 {mu}m.

Addition of iron for the removal of the β-AlFeSi intermetallic by refining of α-AlFeSi phase in an Al-7.5Si-3.6Cu alloy

International Nuclear Information System (INIS)

Belmares-Perales, S.; Zaldivar-Cadena, A.A.

2010-01-01

Addition of iron into the molten metal for the removal of the β-AlFeSi intermetallic by refining of α-AlFeSi phase has been studied. Solidification conditions and composition determine the final microstructure and mechanical properties of a casting piece. It is known that increasing the iron content will produce an increasing of the α-AlFeSi and β-AlFeSi phases. This phenomenon was confirmed with calculations made by Thermo-Calc TM software and validated with experimental results, however, the technique of iron addition in this study plays an important role on the solidification kinetics of these iron phases because the refining of α-AlFeSi and removal of β-AlFeSi phases can be improved. Final results showed an improvement in mechanical properties by removal and refining of β-AlFeSi and α-AlFeSi phases, respectively. This study shows a new method of removal of β-AlFeSi that could be adopted in the aluminum smelting industry in aluminum alloys with a low cooling rate with a secondary dendritic spacing of about 37 μm.

Iron, folacin, vitamin B12 and zinc status and immune response in elderly subjects in the Washington D.C. metropolitan area

International Nuclear Information System (INIS)

Henry-Christian, J.R.

1986-01-01

The iron, folacin, vitamin B 12 , and zinc status of a group of economically and socially disadvantaged elderly persons in the Washington Metropolitan Area was evaluated. Factors related to deficiencies of these nutrients, the relationships between the status of these nutrients and cell-mediated immunity, and the relationships of iron, folacin and vitamin B 12 status to hemoglobin levels in the subjects were also examined. It was also determined whether there were any interactions among iron, folacin, vitamin B 12 and zinc status in their relationships to cell-mediated immunity. Socio-demographic and nutritional data on the subjects were obtained using a questionnaire. Dietary data were obtained using a dietary record. A fasting blood sample was drawn and the levels of ferritin, folate and vitamin B 12 , and the erythrocyte levels of folate were determined by radioassay. Plasma and hair zinc levels were determined by atomic absorption spectrophotometry. Cell-mediated immune response was determined by transformation of peripheral blood lymphocytes after stimulation by mitogens, and by allogenic lymphocytes in the mixed lymphocyte reaction

Preparation and biodistribution of {sup 59}Fe-radiolabelled iron oxide nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Pospisilova, Martina, E-mail: martinapospisilova@gmail.com; Zapotocky, Vojtech; Nesporova, Kristina [Contipro a.s (Czech Republic); Laznicek, Milan; Laznickova, Alice [Charles University, Faculty of Pharmacy in Hradec Králové (Czech Republic); Zidek, Ondrej; Cepa, Martin; Vagnerova, Hana; Velebny, Vladimir [Contipro a.s (Czech Republic)

2017-02-15

We report on the {sup 59}Fe radiolabelling of iron oxide nanoparticle cores through post-synthetic isotope exchange ({sup 59}Fe-IONP{sub ex}) and precursor labelling ({sup 59}Fe-IONP{sub pre}). Scanning electron microscopy and dynamic light scattering measurements showed no impact of radiolabelling on nanoparticle size or morphology. While incorporation efficiencies of these methods are comparable—83 and 90% for precursor labelling and post-synthetic isotope exchange, respectively—{sup 59}Fe-IONP{sub pre} exhibited much higher radiochemical stability in citrated human plasma. Quantitative ex vivo biodistribution study of {sup 59}Fe-IONP{sub pre} coated with triethylene glycol was performed in Wistar rats. Following the intravenous administration, high {sup 59}Fe concentration was observed in the lung and the organs of the reticuloendothelial system such as the liver, the spleen and the femur.

Microwave digestion for determination content of iron and zinc total in food

International Nuclear Information System (INIS)

Silva Trejos, Paulina

2012-01-01

The food digestion procedure was optimized by means of a microwave oven, to quantify the iron and total zinc in different matrices by atomic absorption spectroscopy. The optimum amount of concentrated HNO 3 was analyzed at 65% to digest sample mass determined by assessment of the percentage of recovery obtained with different amount of HNO 3 . The results have not differed from those obtained by officially recommended methods of acid digestion in open systems and calcination. (author) [es

The Pressure-Volume-Temperature Equation of State of Iron-Rich (Mg,Fe)O

Science.gov (United States)

Wicks, J. K.; Jackson, J. M.; Zhuravlev, K. K.; Prakapenka, V.

2012-12-01

Seismic observations near the base of the core-mantle boundary (CMB) have detected 5-20 km thick patches in which the seismic wave velocities are reduced by up to 30%. These ultra-low velocity zones (ULVZs) have been interpreted as aggregates of partially molten material (e.g. Williams and Garnero 1996, Hernlund and Jellinek, 2010) or as solid, iron-enriched residues (e.g. Knittle and Jeanloz, 1991; Mao et al., 2006; Wicks et al., 2010), typically based on proposed sources of velocity reduction. The stabilities of these structure types have been explored through dynamic models that have assembled a relationship between ULVZ stability and density (Hernlund and Tackley, 2007; Bower et al., 2010). Now, to constrain the chemistry of ULVZs, more information is needed on the relationship between density and sound velocity of candidate phases. Recently, we have shown that the characteristically low sound speeds of ULVZs can be produced by small amounts of iron-rich (Mg,Fe)O, which is likely to be found in iron-rich assemblages based on current partitioning studies (eg. Sakai et al., 2010; Tange et al., 2009). We determined the Debye velocity (VD) of (Mg.1657Fe.84)O using nuclear resonant inelastic x-ray scattering (NRIXS), and calculated the seismically relevant compressional (VP) and shear (VS) wave velocities up to 120 GPa using an equation of state of a similar composition (Wicks et al., 2010). These densities and sound velocities, in turn, are consistent with reasonable morphologies of modeled solid ULVZs (Bower et al., 2011). To increase the accuracy of density and sound velocity predictions, measurements must be made at elevated temperatures to correctly predict the properties of iron-rich (Mg,Fe)O at mantle conditions. In this study, we present the pressure-volume-temperature equation of state of (Mg.0657Fe.94)O measured up to pressures of 120 GPa and temperatures of 2000 K. Volume was measured with x-ray diffraction at beamline 13-ID-D of the Advanced Photon

Investigation on effect of iron and corundum content on corrosion resistance of the NiFe-Al2O3 coatings

International Nuclear Information System (INIS)

Starosta, R.; Zielinski, A.

1999-01-01

The alloy NiFe and composite NiFe-Al 2 O 3 coatings, obtained by electrodeposition on the base of cast iron, were investigated. The iron content in alloy coatings was dependent on iron content in galvanic bath, and was estimated by means of X-ray microanalysis at 18.5 wt. pct. and 41.2 wt. pct. No existence of ordered Ni 3 Fe phase was found by diffraction technique. Both potentiodynamic and impedance measurements disclosed that a presence of Al 2 O 3 or increasing iron content in the layer caused the decrease in corrosion resistance. (author)

Environmental application of millimeter-scale sponge iron (s-Fe{sup 0}) particles (II): The effect of surface copper

Energy Technology Data Exchange (ETDEWEB)

Ju, Yongming, E-mail: juyongming@scies.org [South China Institute of Environmental Sciences, The Ministry of Environmental Protection of the PRC, Guangzhou 510655 (China); Liu, Xiaowen, E-mail: liuxiaowen@scies.org [South China Institute of Environmental Sciences, The Ministry of Environmental Protection of the PRC, Guangzhou 510655 (China); Liu, Runlong; Li, Guohua; Wang, Xiaoyan; Yang, Yanyan; Wei, Dongyang; Fang, Jiande [South China Institute of Environmental Sciences, The Ministry of Environmental Protection of the PRC, Guangzhou 510655 (China); Dionysiou, Dionysios D., E-mail: dionysios.d.dionysiou@uc.edu [Environmental Engineering and Science Program, Department of Biomedical, Chemical and Environmental Engineering (DBCEE), University of Cincinnati, Cincinnati, Ohio 45221-0012 (United States)

2015-04-28

Highlights: • Facile reduction reaction achieves decoration of Cu{sup 0} onto the surface of s-Fe{sup 0}. • The removal efficiency of RhB over Cu{sup 0}–s-Fe{sup 0} was similar to that of Cu{sup 0}–nZVI. • Cu{sup 0}–s-Fe{sup 0} can operate under mild condition with lower cost compared to nZVI. • The reductive mechanism over Cu{sup 0}–s-Fe{sup 0} under US condition is also elucidated. - Abstract: To enhance the catalytic reactivity of millimeter-scale particles of sponge iron (s-Fe{sup 0}), Cu{sup 2+} ions were deposited on the surface of s-Fe{sup 0} using a simple direct reduction reaction, and the catalytic properties of the bimetallic system was tested for removal of rhodamine B (RhB) from an aqueous solution. The influence of Cu{sup 0} loading, catalyst dosage, particle size, initial RhB concentration, and initial pH were investigated, and the recyclability of the catalyst was also assessed. The results demonstrate that the 3 ∼ 5 millimeter s-Fe{sup 0} particles (s-Fe{sup 0}(3 ∼ 5 mm)) with 5 wt% Cu loading gave the best results. The removal of RhB followed two-step, pseudo-first-order reaction kinetics. Cu{sup 0}–s-Fe{sup 0} showed excellent stability after five reuse cycles. Cu{sup 0}–s-Fe{sup 0} possesses great advantages compared to nanoscale zero-valent iron, iron power, and iron flakes as well as its bimetals. The surface Cu{sup 0} apparently catalyzes the production of reactive hydrogen atoms for indirect reaction and generates Fe-Cu galvanic cells that enhance electron transfer for direct reaction. This bimetallic catalyst shows great potential for the pre-treatment of recalcitrant wastewaters. Additionally, some oxides containing iron element are selected to simulate the adsorption process. The results prove that the adsorption process of FeOOH, Fe{sub 2}O{sub 3} and Fe{sub 3}O{sub 4} played minor role for the removal of RhB.

[The relevance of the trace elements zinc and iron in the milk fever disease of cattle].

Science.gov (United States)

Heilig, M; Bäuml, D; Fürll, M

2014-01-01

The aim of this study was to analyse the concentrations of Zn and Fe as well as their relationships to metabolic parameters in milk fever cows. A total of 195 Simmental cows, downer cows and clinically healthy control animals were divided into five groups: a) control group (CG, n = 21), b) all cows with milk fever (MF) (n = 174), c) MF cows without additional diseases (n = 145), d) cows with MF and mastitis (n = 10) and e) cows with retained placenta or endometritis (n = 19). Selenium (Se), zinc (Zn), iron (Fe), calcium (Ca), inorganic phosphorus (Pi), tumour necrosis factor α (TNFα), haptoglobin (Hp), antioxidants (Trolox Equivalent Antioxidative Capacity: TEAC), non-esterified fatty acids (NEFA), beta-hydroxybutyrate (BHB), bilirubin, urea, creatinine, glucose, cholesterol, gamma-glutamyl transferase (GGT) and alkaline phosphatase (AP) were analysed in the blood serum. The concentrations of Zn, Fe, Ca, Pi and TEAC were lower in groups b) to e) whereas Hp was higher than in the CG (p ≤ 0.05). In group c), lower Ca and Pi concentrations were found when compared to groups d) and e) (p ≤ 0.05). In group e), Zn concentrations were significantly lower than in group c) (p ≤ 0.05). Zn was negatively correlated with K (CG) and positively correlated with TEAC, Cu, Mn and Fe (groups b and c) and with Mn (group e) (p ≤ 0.05). Fe was positively correlated with Ca (group c), Pi (group c), K (groups b and c) and Mg (groups b-d) as well as with Zn, Cu and Se (groups b and c) (p ≤ 0.05). In groups b) and c), TNFα was increased and negatively correlated with Fe (p ≤ 0.05). AP activity in groups b) and e) was lower than in the CG (p ≤ 0.05). These results and literature data support the hypothesis that Zn and Fe could be engaged in bone metabolism and be involved in the pathogenesis of MF. The concentrations of Hp and TEAC support this interpretation. Control of the Zn and Fe status of cows and Zn supplementation should be included in the

In-gap bound states induced by interstitial Fe impurities in iron-based superconductors

Energy Technology Data Exchange (ETDEWEB)

Zhang, Degang, E-mail: degangzhang@yahoo.com

2015-12-15

Highlights: • We provide an explanation for the interesting STM observation of the robust zero energy bound state on the interstitial Fe impurities in iron-based superconductors. - Abstract: Based on a two-orbit four-band tight binding model, we investigate the low-lying electronic states around the interstitial excess Fe ions in the iron-based superconductors by using T-matrix approach. It is shown that the local density of states at the interstitial Fe impurity (IFI) possesses a strong resonance inside the gap, which seems to be insensitive to the doping and the pairing symmetry in the Fe–Fe plane, while a single or two resonances appear at the nearest neighboring (NN) Fe sites. The location and height of the resonance peaks only depend on the hopping t and the pairing parameter Δ{sub I} between the IFI and the NN Fe sites. These in-gap resonances are originated in the Andreev’s bound states due to the quasiparticle tunneling through the IFI, leading to the change of the magnitude of the superconducting order parameter. When both t and Δ{sub I} are small, this robust zero-energy bound state near the IFI is consistent with recent scanning tunneling microscopy observations.

Fenton-like oxidation of 4-chlorophenol using H2O2 in situ generated by Zn-Fe-CNTs composite.

Science.gov (United States)

Liu, Yong; Fan, Qing; Liu, Yanlan; Wang, Jianlong

2018-05-15

In this paper, a zinc-iron-carbon nanotubes (Zn-Fe-CNTs) composite was prepared, characterized and used to develop a Fenton-like system of Zn-Fe-CNTs/O 2 for the degradation of 4-chlorophenol (4-CP), in which H 2 O 2 was generated in situ from zinc-carbon galvanic cells and oxygen in aqueous solution was activated by iron attached on the surface of CNTs to produce ·OH radicals for the oxidation of 4-CP. The experimental results showed that the particles of Zn and Fe in Zn-Fe-CNTs composite were adhered to the surface of CNTs, which accelerated the electron transfer process. The BET area of Zn-Fe-CNTs composite was 32.9 m 2 /g. The contents of Zn and Fe (% w) in the composite were 44.7% and 4.2%, respectively. The removal efficiency of 4-CP and TOC in Zn-Fe-CNTs/O 2 system was 90.8% and 52.9%, respectively, with the initial pH of 2.0, O 2 flow rate of 800 mL/min, Zn-Fe-CNTs dosage of 1.0 g/L, 4-CP concentration of 50 mg/L and reaction time of 20 min. Based on the analysis of the degradation intermediate products with LC-MS and IC, a possible degradation pathway of 4-CP in Zn-Fe-CNTs/O 2 system was proposed. Copyright © 2018 Elsevier Ltd. All rights reserved.

Evaluation of iron and zinc bioavailability of beans targeted for biofortification using in vitro and in vivo models and their effect on the nutritional status of preschool children.

Science.gov (United States)

Vaz-Tostes, Maria das Graças; Verediano, Thaisa Agrizzi; de Mejia, Elvira Gonzalez; Brunoro Costa, Neuza Maria

2016-03-15

Biofortified beans have been produced with higher nutrient concentrations. The objective was to evaluate the in vitro and in vivo iron and zinc bioavailability of common beans Pontal (PO), targeted for biofortification, compared with conventional Perola (PE) and their effects on the iron and zinc nutritional status of preschool children. In Caco-2 cells, PO and PE beans did not show differences in ferritin (PO, 13.1 ± 1.4; PE, 13.6 ± 1.4 ng mg(-1) protein) or zinc uptake (PO, 15.9 ± 1.5; PE, 15.5 ± 3.5 µmol mg(-1) protein). In the rat, PO and PE beans presented high iron bioavailability (PO, 109.6 ± 29.5; PE, 110.7 ± 13.9%). In preschool children, no changes were observed in iron and zinc nutritional status comparing before and after PO consumption (ferritin, 41.2 ± 23.2 and 28.9 ± 40.4 µg L(-1) ; hemoglobin, 13.7 ± 2.2 and 13.1 ± 3.2 g dL(-1) ; plasma zinc, 119.2 ± 24.5 and 133.9 ± 57.7 µg dL(-1) ; erythrocyte zinc, 53.5 ± 13.8 and 59.4 ± 17.1 µg g(-1) hemoglobin). Iron and zinc bioavailability in PO and PE beans was not statistically different using either cell culture, animal or human models. Efforts should focus on increasing mineral bioavailability of beans targeted for biofortification. © 2015 Society of Chemical Industry.

A Question of Balance: Facing the challenges of Cu, Fe and Zn Homeostasis

OpenAIRE

Palmer, Christine; Guerinot, Mary Lou

2009-01-01

Plants have recently moved into the spotlight with the growing realization that the world needs solutions to energy and food production that are sustainable and environmentally sound. Iron (Fe), copper (Cu), and zinc (Zn) are essential for plant growth and development, yet the same properties that make these transition metals indispensable can also make them deadly in excess. Fe and Cu are most often utilized for their redox properties, while Zn is primarily utilized for is ability to act as ...

Spatially Resolved Distribution of Fe Species around Microbes at the Submicron Scale in Natural Bacteriogenic Iron Oxides.

Science.gov (United States)

Suga, Hiroki; Kikuchi, Sakiko; Takeichi, Yasuo; Miyamoto, Chihiro; Miyahara, Masaaki; Mitsunobu, Satoshi; Ohigashi, Takuji; Mase, Kazuhiko; Ono, Kanta; Takahashi, Yoshio

2017-09-27

Natural bacteriogenic iron oxides (BIOS) were investigated using local-analyzable synchrotron-based scanning transmission X-ray microscopy (STXM) with a submicron-scale resolution. Cell, cell sheath interface (EPS), and sheath in the BIOS were clearly depicted using C-, N-, and O- near edge X-ray absorption fine structure (NEXAFS) obtained through STXM measurements. Fe-NEXAFS obtained from different regions of BIOS indicated that the most dominant iron mineral species was ferrihydrite. Fe(II)- and/or Fe(III)-acidic polysaccharides accompanied ferrihydrite near the cell and EPS regions. Our STXM/NEXAFS analysis showed that Fe species change continuously between the cell, EPS, and sheath under several 10-nm scales.

Growth and microstructure of iron nitride layers and pore formation in {epsilon}-Fe{sub 3}N

Energy Technology Data Exchange (ETDEWEB)

Middendorf, C.; Mader, W. [Univ. Bonn, Inst. fuer Anorganische Chemie, Bonn (Germany)

2003-03-01

Layers of {epsilon}-Fe{sub 3}N and {gamma}'-Fe{sub 4}N on ferrite were produced by nitriding iron single crystals or rolled sheets of iron in flowing ammonia at 520 C. The nitride layers were characterised using X-ray diffraction, light microscopy as well as scanning and transmission electron microscopy. The compound layer consists of {epsilon}-Fe{sub 3}N at the surface and of {gamma}'-Fe{sub 4}N facing the ferrite. After 4 h of nitriding, pores develop in the near surface region of {epsilon}-Fe{sub 3}N showing more or less open porosity. Growth of the entire compound layer as well as of the massive and the porous {epsilon}-Fe{sub 3}N sublayer is diffusion-controlled and follows a parabolic growth rate. The {gamma}'-Fe{sub 4}N layer is formed as a transition phase within a narrow interval of nitrogen activity, and it shows little growth in thickness. The transformation of {gamma}'-Fe{sub 4}N to {epsilon}-Fe{sub 3}N is topotactic, where the orientation of the closed-packed iron layers of the crystal structures is preserved. Determination of lattice plane spacings was possible by X-ray diffraction, and this was correlated to the nitrogen content of {epsilon}-Fe{sub 3}N. While the porous layer exhibits an enhanced nitrogen content corresponding to the chemical composition Fe{sub 3}N{sub 1.1}, the massive e Fe{sub 3}N layer corresponds to Fe{sub 3}N{sub 1.0}. The pore formation in {epsilon}-Fe{sub 3}N{sub 1.1} is concluded to be the result of excess nitrogen atoms on non-structural sites, which have a high mobility. Therefore, recombination of excess nitrogen to molecular N{sub 2} at lattice defects is preferred in {epsilon}-Fe{sub 3}N with high nitrogen content compared to stoichiometric {epsilon}-Fe{sub 3}N{sub 1.0} with nitrogen on only structural sites. (orig.)

Resonance Raman detection of iron-ligand vibrations in cyano(pyridine)(octaethylporphinato)iron(III): Effects of pyridine basicity on the Fe-CN bond strength

International Nuclear Information System (INIS)

Uno, Tadayuki; Hatano, Keiichiro; Nishimura, Yoshifumi; Arata, Yoji

1988-01-01

The influence of axial ligand basicity on the bonding of iron(III) in cyano adducts of octaethylporphyrin has been studied by resonance Raman spectroscopy. In a six-coordinate ferric low-spin complex, cyano(pyridine)(octaethylporphinato)iron(III), Fe(OEP)(CN)(py), Raman lines at 449 and 191 cm -1 were assigned to the ν(Fe-CN) and ν(Fe-py) stretching modes, respectively. When pyridine was displaced with its derivatives, py-X, where X = 4-cyano, 3-acetyl, 3-methyl, 4-methyl, 3,4-dimethyl, and 4-dimethylamino, the ν(Fe-CN) stretching frequency was found to decrease in the complex with a high pyridine basicity. It was concluded that the stronger the trans pyridine basicity, the weaker the iron-carbon (cyanide) bond. A clear frequency shift was observed in the ν 4 model, though most of the porphyrin vibrations were insensitive to the ligand substitution. The frequency of the ν 4 mode, which is the C a -N(pyrrole) breathing vibration of the porphyrin skeleton, was found to increase with an increase in pyridine basicity. This is contrary to what was found in ferrous low-spin hemes as CO complexes. The ν 4 shift in the CN complexes was explained in terms of forward π donation; donation of electrons from the porphyrin π orbital to the d π vacancy of the low-spin iron(III) weakened the C a -N(pyrrole) bonds and hence decreased the ν 4 frequency. 32 references, 8 figures

Studies of the rare earth-iron interactions in the orthoferrites GdFeO3 and HoFeO3

International Nuclear Information System (INIS)

Sakata, T.; Enomura, A.

1979-01-01

The magnetic behaviour of GdFeO 3 and HoFeO 3 is investigated by means of a Faraday type magnetic balance in a temperature range where rare earth ions are in the paramagnetic state. The results are analyzed in terms of an effective field at a rare earth ion site. Thereby the isotropic exchange field as well as the magnetic dipole field are taken into account. By this means the exchange integral, J/k(K), between an iron ion and a rare earth ion may be estimated to be 0.23 for GdFeO 3 and 0.25 for HoFeO 3 , respectively. (author)

Whole-body iron-59 retention measurements for estimating the iron status of piglets

International Nuclear Information System (INIS)

Pfau, A.; Rudolphi, K.; Heinrich, H.C.; Gabbe, E.E.

1976-01-01

A large-volume, 4π whole-body liquid scintillation detector was used to determine 59 Fe absorption in 173 one-to-six-weeks-old piglets with normal and depleted iron stores. Values of intestinal absorption from a 10 μmole (corresponds to 0.558 mg) 59 Fe 2+ test dose were compared with levels of haemoglobin, haematocrit, and serum iron as well as with stainable diffuse iron of bone marrow reticuloendothelial cells, and the dose relationship of intestinal iron absorption from 59 Fe-labelled FeSO 4 and methaemoglobin was measured. The investigations indicated that neither blood parameters, cytochemical gradings nor absorption levels from the 59 Fe test dose alone were sufficient to describe quantitatively the various stages of iron deficiency in piglets. A synopsis of all parameters appeared to be necessary for defining normal iron status and prelatent, latent and manifest iron deficiency. Piglets fed on sows' milk only developed manifest iron deficiency within the first three weeks of age. After an access to soil and/or creep feed from the eighth day of age, or intramuscular injections of 200 mg Fe as iron-dextran at three days of age, or injections of 200 or 400 mg Fe combined with access to creep feed, stages of manifest, latent or prelatent iron deficiency could be observed. For an iron-dextran dose of 800 mg Fe injected in amounts of 400 mg Fe at 3 and 10 days of age, a normal iron status was obtained in three-week-old piglets. The iron dose relationship indicated that 20 mg Fe administered orally as FeSO 4 or 40 mg Fe as methaemoglobin-Fe daily should cover the iron requirement of piglets for the first three weeks of life, whereas a three-week total of iron given orally in a single dose would lead to unphysiological or fatal conditions in nursing pigs. (author)

Iron and zinc complexation in wild-type and ferritin-expressing wheat grain: implications for mineral transport into developing grain

DEFF Research Database (Denmark)

Neal, Andrew L; Geraki, Kalotina; Borg, Søren

2013-01-01

of modified complexation of both metals in transgenic grain overexpressing wheat ferritin. For zinc, there is a consistent doubling of the number of complexing phosphorus atoms. Although there is some EXAFS evidence for iron phytate in ferritin-expressing grain, there is also evidence of a structure lacking......We have used synchrotron-based X-ray fluorescence and absorption techniques to establish both metal distribution and complexation in mature wheat grains. In planta, extended X-ray absorption fine structure (EXAFS) spectroscopy reveals iron phytate and zinc phytate structures in aleurone cells...... of ferritin-expressing grains is quite different from that in wild-type grain. This may explain why the raised levels of minerals transported to the developing grain accumulate within the crease region of the transgenic grain....

Effect of excess dietary iron as ferrous sulfate and excess dietary ascorbic acid on liver zinc, copper and sulfhydryl groups and the ovary

International Nuclear Information System (INIS)

Edwards, C.H.; Adkins, J.S.; Harrison, B.

1986-01-01

Female guinea pigs of the NIH 13/N strain, weighing between 475 and 512 g, were fed diets supplemented with 50 to 2500 mg of iron per kg of diet as ferrous sulfate and 0.2 to 8.0 g of ascorbic acid per kg of diet. A significant effect was observed on tissue copper and zinc, ovary weight and liver protein sulfhydryl groups. The mean ovary weight for guinea pigs fed 2500 mg of iron was significantly less than that of animals fed 50 mg of iron, 0.045 +/- 0.012 g and 0.061 +/- 0.009 g, respectively. Liver zinc content of animals fed 2500 mg of iron and 200 mg of ascorbic acid per kg of diet was significantly less than that of animals fed 50 mg of iron and 200 mg of ascorbic acid, 16.3 +/- 3.3 μg and 19.6 +/- 1.6 μg, respectively. There was no difference in liver copper due to dietary iron, but when dietary ascorbic acid was increased to 8 g per kg of diet, there was a significant decrease (from 22.8 +/- 8.1 μg to 10.5 +/- 4.8 μg) in liver copper. Excess dietary ascorbic acid decreased ovarian zinc significantly when increased to 8 g per kg of diet, 2929 +/- 919 μg vs 1661 +/- 471 μg, respectively, when compared to the control group

On the origin of discontinuity of the hyperfine fields at {sup 57}Fe nuclei in bulk iron and aerosol Fe nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Petrov, Yu.I. [Semenov Institute of Chemical Physics, Russian Academy of Sciences, Kosygin str. 4, 119991, GSP-1, Moscow (Russian Federation); Shafranovsky, E.A., E-mail: shafr@chph.ras.r [Semenov Institute of Chemical Physics, Russian Academy of Sciences, Kosygin str. 4, 119991, GSP-1, Moscow (Russian Federation); Casas, Ll. [Departament de Geologia, Universitat Autonoma de Barcelona, Edifici C, Campus de la UAB, 08193 Bellaterra (Spain); Molins, E. [Institut de Ciencia de Materials de Barcelona (ICMAB-CSIC), Campus de la UAB, 08193 Bellaterra (Spain)

2011-03-14

Advancing the early work in which a discontinuity of hyperfine fields at {sup 57}Fe nuclei in bulk iron and in aerosol Fe nanoparticles has been revealed by analyzing their Moessbauer spectra the present Letter evidences that the existence of several peaks in the hyperfine distribution (HFD) for bulk Fe is caused with the internal magnetic fields owing to its multidomain structure whereas aerosol Fe nanoparticles are single-domain and show only a unique peak in HFD. This argument has been corroborated by transformation of the HFD pattern for Fe foil after applying the external magnetic field of 0.03 T.

Microstructure and properties of multiphase sintered cermets Fe-Fe{sub 2}B; Mikrostruktura i wlasnosci spiekanych reakcyjnie cermetali Fe-Fe{sub 2}B

Energy Technology Data Exchange (ETDEWEB)

Nowacki, J. [Wydzial Inzynierii Materialowej, Politechnika Szczecinska, Szczecin (Poland); Klimek, L. [Instytut Inzynierii Materialowej i Technik Bezwiorowych, Politechnika Lodzka, Lodz (Poland)

1998-12-31

The process of multiphase sintering of iron in the vacuum has been analysed. As a result of the process iron-iron boride cermets have been produced. Fe-Fe{sub 2}B cermets were obtained as a result of sintering of the Fe and B pure elements in the vacuum. Attemps at sintering in the solid phase and with the participation of the liquid phase, the Fe-Fe{sub 2}B eutectic, have been made. Metallographic qualitative and quantitative studies, X-ray structural qualitative and qauantitative analysis allowed to determine the structure of Fe{sub 2}B cermets, as well as a description of the kinetics of quantitative changes in phase proportions in the course of sintering. It has been found that their structure varies widely depending on sintering parameters and the composition of the sinters. Measurements of the Fe-Fe{sub 2}B cermets hardness and measurements on wear during dry friction by the pin-on-disc method have shown distinct advantages of the cermets as a modern constructional materials. The hardness of Fe-Fe{sub 2}B cermets, depending on their chemical composition and sintering parameters, ranges widely from 150 to 1500 HV, and their resistance to wear is comparable to that of diffusively boronized steels. FeFe{sub 2}B cermets are a composite material in which iron boride, Fe{sub 2}B, with a hardness of about 1800 HV plays the role of the reinforcement,while iron-iron boride, Fe-Fe{sub 2}B, with a hardness of about 500 HV plays the role of matrix. The eutectic in the spaces between iron boride grains is composed of boron solid solution plates in iron with a hardness of arround 250 HV, and iron boride, Fe{sub 2}B, plates with a hardness of approximaly 1800 HV. The combination of such different materials, a hard reinforcement and a relatively plastic matrix produces favourable properties of the cermet thus produced high hardness (1500 HV) constant over whole cross section of the material, resistance of abrasive wear and acceptable ductility. The properties mentioned above

Iron Content Affects Lipogenic Gene Expression in the Muscle of Nelore Beef Cattle.

Directory of Open Access Journals (Sweden)

Wellison Jarles da Silva Diniz

Full Text Available Iron (Fe is an essential mineral for metabolism and plays a central role in a range of biochemical processes. Therefore, this study aimed to identify differentially expressed (DE genes and metabolic pathways in Longissimus dorsi (LD muscle from cattle with divergent iron content, as well as to investigate the likely role of these DE genes in biological processes underlying beef quality parameters. Samples for RNA extraction for sequencing and iron, copper, manganese, and zinc determination were collected from LD muscles at slaughter. Eight Nelore steers, with extreme genomic estimated breeding values for iron content (Fe-GEBV, were selected from a reference population of 373 animals. From the 49 annotated DE genes (FDR<0.05 found between the two groups, 18 were up-regulated and 31 down-regulated for the animals in the low Fe-GEBV group. The functional enrichment analyses identified several biological processes, such as lipid transport and metabolism, and cell growth. Lipid metabolism was the main pathway observed in the analysis of metabolic and canonical signaling pathways for the genes identified as DE, including the genes FASN, FABP4, and THRSP, which are functional candidates for beef quality, suggesting reduced lipogenic activities with lower iron content. Our results indicate metabolic pathways that are partially influenced by iron, contributing to a better understanding of its participation in skeletal muscle physiology.

Normal iron absorption determined by means of whole body counting and red cell incorporation of 59Fe

International Nuclear Information System (INIS)

Larsen, L.; Milman, N.

1977-01-01

Gastrointestinal iron absorption was measured in 27 normal subjects (19 females and 8 males) by means of whole body counting. Whole body retention 14 days after oral administration of 10μCi 59 Fe together with a carrier dose of 9.9 mg Fe 2+ (as sulphate), was used as an expression of absorption. The percentage incorporation in the total erythrocyte mass of administered 59 Fe (erythrocyte incorporation) and of absorbed 59 Fe (red cell utilization) was also estimated. Geometric mean iron absorption was 8.3+-2.1 (SD% in females, 9.1+-2.2 % in males and 8.5+-2.1 % in the entire series. The difference between males and females was not significant. Erythrocyte incorporation was 7.7+-2.2 (SD) % (geometric mean) in the entire series and the correlation between iron absorption and erythrocyte incorporation was highly significant (r = 0.96,P < 0.001). Red cell utilization averaged 92.9 +- 4.0 (SEM)% (arithmetic mean) in the entire series. (author)

Isotope-aided studies of the bioavailability of iron from Myanmar diets

International Nuclear Information System (INIS)

Khin Maung Naing; Myo Khin

1994-01-01

A study was conducted to determine the dietary intakes and serum levels of iron and zinc in twenty apparently healthy Myanmar adults (10 males and 10 females), using atomic absorption spetrophotometry. The mean iron intake of females was found to be lower than the FAO/WHO recommended allowance whereas for men it was found to be adequate. The mean serum iron concentration in females was found to be significantly lower than in males (p 4· 7H 2 O, and 5g of sodium-hexa-metaphosphate thoroughly and then the mixture was again mixed with 1 kg of salt. This was done in July 1992. The stability of iron-fortified salt (i.e. change in colour of salt) as well as ferrous and ferric iron content of iron-fortified salt, were determined at monthly intervals. The iron-fortified salt was found to be stable up to the time of report writing, i.e. 3rd week of October, 1992. The ferrous iron content of salt was found to range between 0.95 to 0.98 mg Fe/g salt. Bioavailability studies of iron from two types of standard meals, one containing staple rice, 32 g of fish, water cress, watery fish paste and cucumber, and another containing boiled peas in place of fish, were conducted on two groups of male subjects using 59 Fe as an extrinsic tag. Bioavailability studies of iron from the above two types of meals cooked with iron-fortified salt (1 mg/g salt) were also conducted on the same groups of subjects using 59 Fe as an extrinsic tag. Reference dose absorption of iron will be conducted. This work is in progress. (author). 6 refs, 4 tabs

Use of radioisotopes in studying iron metabolism in humans in Sri Lanka

International Nuclear Information System (INIS)

Liyanage, C.E.; Thabrew, M.I.

1994-01-01

Anaemia due to iron deficiency is the commonest haematological problem found in Sri Lankan pregnant women and pre-school children. The reported prevalence rates amongst pregnant and lactating women ranged from 60-80%. The present study revealed that 3% of pregnant women had satisfactory iron stores and 57% had virtually no iron stores. Routine iron supplementation is justified not only to correct the anaemia but also to build up the maternal iron stores. In a longitudinal study of 100 pregnant women a very high prevalence was observed in spite of the fact that the population studied was on iron supplementation. A very poor compliance on iron therapy was seen. The incidence of low birth weight observed was 32%, quite similar to that has been reported previously for Sri Lanka. Therefore, further longitudinal studies have been designed to find out the efficacy of the present supplementary programme. In Galle District 54.5% of the pre-school children were found clearly anaemic and another 20% had evidence of iron depletion. As the dietary intake of iron was marginal, the weaning foods that are in practice were tested for iron availability. Iron absorption/availability studies by in-vivo (extrinsic tag method) and in-vitro (using radioiron 59 Fe tracer) methods have shown a very poor (less than 5%) availability in many of the commonly used weaning foods. A statistically significant decrease in iron availability was seen with increase in amount of polyphenols mainly in some of the preparations made with green leaves. Addition of ascorbic acid rich food items showed an increase in iron availability (by 2-6 times). Dietary zinc intake of 46 children (2-5 yrs) was found 2-4 mg/1000 kcal, relating to total energy intake. Mean plasma zinc concentration of these children was 13.8±0.8 μmol/L. Therefore further studies on the improvement of zinc and iron availability in weaning foods have been designed to be done in future. (author). 3 refs, 1 fig

Moessbauer Study of Electrodeposited Fe/Fe-Oxide Multilayers

International Nuclear Information System (INIS)

Kuzmann, E.; Homonnay, Z.; Klencsar, Z.; Vertes, A.; Lakatos-Varsanyi, M.; Miko, A.; Varga, L.K.; Kalman, E.; Nagy, F.

2005-01-01

Iron has been deposited electrochemically by short current pulses in Na-saccharin containing FeII-chloride and sulphate solution electrolytes. Combined electrochemical techniques with initial pulse plating of iron nanolayer and its subsequent anodic oxidation under potential control have been used for production of Fe/Fe-oxide multilayers. 57Fe CEM spectra of pulse plated iron revealed the presence of a minor doublet attributed mainly to γ-FeOOH in addition to the dominant sextet of α-iron. In the case of anodically oxidized pulse plated iron and of samples after repeated deposition of anodically oxidized pulse plated iron an additional minor doublet, assigned to ferrous chloride, also appears in the Moessbauer spectra. A significant change in the magnetic anisotropy of α-iron was observed with the anodic oxidation. The thickness of the layers were estimated from the CEM spectrum data by a modified computer program of the Liljequist method. The coercive field and the power loss versus frequency data showed that the pulse plated iron cores are good inductive elements up to several kHz frequencies

Sol-gel based optical sensor for determination of Fe (II): a novel probe for iron speciation.

Science.gov (United States)

Samadi-Maybodi, Abdolraouf; Rezaei, Vida; Rastegarzadeh, Saadat

2015-02-05

A highly selective optical sensor for Fe (II) ions was developed based on entrapment of a sensitive reagent, 2,4,6-tri(2-pyridyl)-s-triazine (TPTZ), in a silica sol-gel thin film coated on a glass substrate. The thin films fabricated based on tetraethoxysilane (TEOS) as precursor, sol-gel pH∼3, water:alkoxyde ratio of 4:1 and TPTZ concentration of 0.112 mol L(-1). The influence of sol-gel parameters on sensing behavior of the fabricated sensor was also investigated. The fabricated sensor can be used for determination of Fe (II) ion with an outstanding high selectivity over a dynamic range of 5-115 ng mL(-1) and a detection limit of 1.68 ng mL(-1). It also showed reproducible results with relative standard deviation of 3.5% and 1.27% for 10 and 90 ng mL(-1) of Fe (II), respectively, along with a fast response time of ∼120 s. Total iron also was determined after reduction of Fe (III) to Fe (II) using ascorbic acid as reducing agent. Then, the concentration of Fe (III) was calculated by subtracting the concentration of Fe (II) from the total iron concentration. Interference studies showed a good selectivity for Fe (II) with trapping TPTZ into sol-gel matrix and appropriately adjusting the structure of doped sol-gel. The sensor was compared with other sensors and was applied to determine iron in different water samples with good results. Copyright © 2014 Elsevier B.V. All rights reserved.

Fever and changes in plasma zinc and iron concentrations in the goat: The role of leukocytic pyrogen

NARCIS (Netherlands)

Verheijden, J.H.M.; Miert, A. S. J. P. A. M. Van; Duin, C.T.M. van; Schotman, A.J.H.; Nieuwenhuis, J.

1984-01-01

In goats with trypanosomiasis (T. vivax or T. congolense) no marked fall in plasma zinc concentration was seen despite high temperature peaks, whereas plasma concentrations of iron tended to undergo some decline. In goats infected with Ehrlichia phagocytophila, there was a marked decline in plasma

Zinc, iron, manganese and copper uptake requirement in response to nitrogen supply and the increased grain yield of summer maize.

Directory of Open Access Journals (Sweden)

Yanfang Xue

Full Text Available The relationships between grain yields and whole-plant accumulation of micronutrients such as zinc (Zn, iron (Fe, manganese (Mn and copper (Cu in maize (Zea mays L. were investigated by studying their reciprocal internal efficiencies (RIEs, g of micronutrient requirement in plant dry matter per Mg of grain. Field experiments were conducted from 2008 to 2011 in North China to evaluate RIEs and shoot micronutrient accumulation dynamics during different growth stages under different yield and nitrogen (N levels. Fe, Mn and Cu RIEs (average 64.4, 18.1 and 5.3 g, respectively were less affected by the yield and N levels. ZnRIE increased by 15% with an increased N supply but decreased from 36.3 to 18.0 g with increasing yield. The effect of cultivars on ZnRIE was similar to that of yield ranges. The substantial decrease in ZnRIE may be attributed to an increased Zn harvest index (from 41% to 60% and decreased Zn concentrations in straw (a 56% decrease and grain (decreased from 16.9 to 12.2 mg kg-1 rather than greater shoot Zn accumulation. Shoot Fe, Mn and Cu accumulation at maturity tended to increase but the proportions of pre-silking shoot Fe, Cu and Zn accumulation consistently decreased (from 95% to 59%, 90% to 71% and 91% to 66%, respectively. The decrease indicated the high reproductive-stage demands for Fe, Zn and Cu with the increasing yields. Optimized N supply achieved the highest yield and tended to increase grain concentrations of micronutrients compared to no or lower N supply. Excessive N supply did not result in any increases in yield or micronutrient nutrition for shoot or grain. These results indicate that optimized N management may be an economical method of improving micronutrient concentrations in maize grain with higher grain yield.

Spatial and temporal distribution of Fe(II) and H2O2 during EisenEx, an open ocean mescoscale iron enrichment

NARCIS (Netherlands)

Croot, Peter L.; Laan, Patrick; Nishioka, Jun; Strass, Volker; Cisewski, Boris; Boye, Marie; Timmermans, Klaas R.; Bellerby, Richard G.; Goldson, Laura; Nightingale, Phil; Baar, Hein J.W. de

2005-01-01

Measurements of Fe(II) and H2O2 were carried out in the Atlantic sector of the Southern Ocean during EisenEx, an iron enrichment experiment. Iron was added on three separate occasions, approximately every 8 days, as a ferrous sulfate (FeSO4) solution. Vertical profiles of Fe(II) showed maxima

Final report on in-reactor uniaxial tensile deformation of pure iron and Fe-Cr alloy

International Nuclear Information System (INIS)

Singh, B.N.; Xiaoxu Huang; Taehtinen, S.; Moilamen, P.; Jacquet, P.; Dekeyser, J.

2007-11-01

Traditionally, the effect of irradiation on mechanical properties of metals and alloys is determined using post-irradiation tests carried out on pre-irradiated specimens and in the absence of irradiation environment. The results of these tests may not be representative of deformation behaviour of materials used in the structural components of a fission or fusion reactor where the materials will be exposed concurrently to displacement damage and external and/or internal stresses. In an effort to evaluate and understand the dynamic response of materials under these conditions, we have recently performed a series of uniaxial tensile tests on Fe-Cr and pure iron specimens in the BR-2 reactor at Mol (Belgium). The present report first provides a brief description of the test facilities and the procedure used for performing the in-reactor tests. The results on the mechanical response of materials during these tests are presented in the form of stress-displacement dose and the conventional stress-strain curves. For comparison, the results of post-irradiation tests and tests carried out on unirradiated specimens are also presented. Results of microstructural investigations on the unirradiated and deformed, irradiated and undeformed, post-irradiation deformed and the in-reactor deformed specimens are also described. During the in-reactor tests the specimens of both Fe-Cr alloy and pure iron deform in a homogeneous manner and do not exhibit the phenomenon of yield drop. An increase in the pre-yield dose increases the yield stress but not the level of maximum flow stress during the in-reactor deformation of Fe-Cr alloy. Neither the in-reactor nor the post-irradiation deformed specimens of Fe-Cr alloy and pure iron showed any evidence of cleared channel formation. Both in Fe-Cr and pure iron, the in-reactor deformation leads to accumulation of dislocations in a homogeneous fashion and only to a modest density. No dislocation cells are formed during the in-reactor or post

Structural characterization of hog iron oxide content glasses obtained from zinc hydrometallurgy wastes

International Nuclear Information System (INIS)

Romero, M.; Rincon, J.M.; Musik, S.; Kozhujharov, W.

1997-01-01

It has been carried out the structural characterization of high oxide content glasses obtained by melting of a goethite industrial waste from the zinc hydrometallurgy with other raw materials as dolomite and glass cullet. The structural characterization has been carried out by X-ray Diffraction (XRD), X-Ray Diffraction by Amorphous Dispersion (RDF) and Mossbauer spectroscopy. It has been determined the interatomic distance, the oxidation state and the coordination of iron atoms in these glasses. (Author) 16 refs

How low does iron go? Chasing the active species in fe-catalyzed cross-coupling reactions.

Science.gov (United States)

Bedford, Robin B

2015-05-19

The catalytic cross-coupling reactions of organic halides or related substrates with organometallic nucleophiles form the cornerstone of many carbon-carbon bond-forming processes. While palladium-based catalysts typically mediate such reactions, there are increasing concerns about the long-term sustainability of palladium in synthesis. This is due to the high cost of palladium, coupled with its low natural abundance, environmentally deleterious extraction (∼6 g of metal are produced per ton of ore), toxicity, and competition for its use from the automotive and consumer electronics sectors. Therefore, there is a growing interest in replacing palladium-based catalysts with those incorporating more earth-abundant elements. With its low cost, high natural abundance, and low toxicity, iron makes a particularly appealing alternative, and accordingly, the development of iron-catalyzed cross-coupling is undergoing explosive growth. However, our understanding of the mechanisms that underpin the iron-based catalytic cycles is still very much in its infancy. Mechanistic insight into catalytic reactions is not only academically important but also allows us to maximize the efficiency of processes or even to develop entirely new transformations. Key to the development of robust mechanistic models for cross-coupling is knowing the lowest oxidation state in the cycle. Once this is established, we can explore subsequent redox processes and build the catalytic manifold. Until we know with confidence what the lowest oxidation state is, any cycles proposed are largely just guesswork. To date, Fe(-II), Fe(-I), Fe(0), Fe(I), and Fe(II) have been proposed as contenders for the lowest-oxidation-state species in the cycle in iron-catalyzed cross-coupling; the aim of this Account is to pull together the various pieces of evidence in support, or otherwise, of each of these suggestions in turn. There currently exists no direct evidence that oxidation states below Fe(0) are active in the

HvZIP7 mediates zinc accumulation in barley (Hordeum vulgare) at moderately high zinc supply

DEFF Research Database (Denmark)

Tiong, Jingwen; Mcdonald, Glenn K.; Genc, Yusuf

2014-01-01

Summary: High expression of zinc (Zn)-regulated, iron-regulated transporter-like protein (ZIP) genes increases root Zn uptake in dicots, leading to high accumulation of Zn in shoots. However, none of the ZIP genes tested previously in monocots could enhance shoot Zn accumulation. In this report...... were also generated to further understand the functions of HvZIP7 in metal transport. HvZIP7 is strongly induced by Zn deficiency, primarily in vascular tissues of roots and leaves, and its protein was localized in the plasma membrane. These properties are similar to its closely related homologs...... in dicots. Overexpression of HvZIP7 in barley plants increased Zn uptake when moderately high concentrations of Zn were supplied. Significantly, there was a specific enhancement of shoot Zn accumulation, with no measurable increase in iron (Fe), manganese (Mn), copper (Cu) or cadmium (Cd). HvZIP7 displays...

Electrical and magnetic behavior of iron doped nickel titanate (Fe{sup 3+}/NiTiO{sub 3}) magnetic nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Lenin, Nayagam; Karthik, Arumugam; Sridharpanday, Mathu; Selvam, Mohanraj; Srither, Saturappan Ravisekaran; Arunmetha, Sundarmoorthy; Paramasivam, Palanisamy; Rajendran, Venkatachalam, E-mail: veerajendran@gmail.com

2016-01-01

Iron doped nickel titanate (Fe{sup 3+}/NiTiO{sub 3}) ferromagnetic nanoparticles with different concentrations of Fe (0.2, 0.4, and 0.6 mol) were synthesized using precipitation route with precursor source such as nickel nitrate and iron nitrate solutions. The prepared magnetic nanopowders were investigated through X-ray diffraction (XRD), Fourier transform infrared, scanning electron microscope, X-ray fluorescence, Brunauer–Emmett–Teller, vibrating sample magnetometer, and electrochemical impedance spectroscopy to explore the structural, ferromagnetic, and dielectric properties. The obtained XRD pattern shows formation of iron doped nickel titanate in orthorhombic structure. The crystallite size ranges from 57 to 21 nm and specific surface area ranges from 11 to 137 m{sup 2} g{sup −1}. The hysteresis loops of nanomagnetic materials show ferromagnetic behavior with higher magnitude of coercivity (H{sub c}) 867–462 Oe. The impedance analysis of ferromagnetic materials explores the ferro-dielectric behavior with enhanced properties of Fe{sup 3+}/NiTiO{sub 3} nanoparticles at higher Fe content. - Highlights: • Iron doped nickel titanate magnetic nanoparticles. • Ferromagnetic magnetism behavior with higher magnitude of coercivity. • Dielectric behavior of ferromagnetic nanoparticles with increase of Fe content.

Iron Fibers Arrays Prepared by Electrodepositing in Reverse Liquid Crystalline

Institute of Scientific and Technical Information of China (English)

ZHAO Suling; LIN Dong; GUAN Jianguo; ZHANG Lianmeng

2006-01-01

Ordered iron fiber arrays were electrodeposited on the surface of zinc foils using "FeSO4 solution-sodium caprylate-Decanol" 3-component reverse hexagonal liquid crystal as soft templates. The structure of the soft templates and the synthesized iron fibers were characterized by polarizing microscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray microanalysis etc. The experimental results show that the synthesized iron fibers with α crystal phase grew up in the form of fiber clusters of about 200 nm along the direction perpendicular to the cathode surface. Each cluster was composed of several tens of fibers. The fibers had almost the same length of more than 10 μm with a diameter of about 50 nm.

Zn and Fe complexes containing a redox active macrocyclic biquinazoline ligand.

Science.gov (United States)

Banerjee, Priyabrata; Company, Anna; Weyhermüller, Thomas; Bill, Eckhard; Hess, Corinna R

2009-04-06

A series of iron and zinc complexes has been synthesized, coordinated by the macrocyclic biquinazoline ligand, 2-4:6-8-bis(3,3,4,4-tetramethyldihydropyrrolo)-10-15-(2,2'-biquinazolino)-[15]-1,3,5,8,10,14-hexaene-1,3,7,9,11,14-N(6) (Mabiq). The Mabiq ligand consists of a bipyrimidine moiety and two dihydropyrrole units. The electronic structures of the metal-Mabiq complexes have been characterized using spectroscopic and density-functional theory (DFT) computational methods. The parent zinc complex exhibits a ligand-centered reduction to generate the metal-coordinated Mabiq radical dianion, establishing the redox non-innocence of this ligand. Iron-Mabiq complexes have been isolated in three oxidation states. This redox series includes low-spin ferric and low-spin ferrous species, as well as an intermediate-spin Fe(II) compound. In the latter complex, the iron ion is antiferromagnetically coupled to a Mabiq-centered pi-radical. The results demonstrate the rich redox chemistry and electronic properties of metal complexes coordinated by the Mabiq ligand.

Iron, zinc and phytic acid in rice from China: wet and dry processing towards improved mineral bioavailability

NARCIS (Netherlands)

Liang, J.

2007-01-01

Rice and rice products supply two thirds of Chinese people with their staple food. Mineral deficiencies, especially of iron and zinc, are prevalent in China, and are caused by insufficient intake and poor bioavailability. Rice and rice products contribute more than 50% of the antinutrient phytic

Distribution of iron cations in natural chromites at different stages of oxidation: a {sup 57}Fe Moessbauer investigation

Energy Technology Data Exchange (ETDEWEB)

Pal, Tapan; Mitra, Sachinath [Jadavpur Univ., Calcutta (India). Dept. of Geological Sciences; Moon, Hi-Soo [Yonsei Univ., Seoul (Korea, Republic of). Dept. of Geology

1994-07-01

{sup 57}Fe Moessbauer spectroscopic investigation of natural chromites from two chromite deposits of India (Sukinda and Byrapur) documents partly inverse spinel structure arising out of oxidation. The spectral fitting was based on allowing a disordering distribution of Fe{sup 2+} and Fe{sup 3+} ions at tetrahedral (A) and octahedral (B) sites. Moessbauer investigation of the samples taken from the physico-chemically distinct two horizons of Sukinda viz. brown ore and grey ores, and Byrapur area revealed three types of iron ion distribution as: Fe{sup 2+}(A), Fe{sup 3+}(A) and Fe{sup 2+}(B) (GC-group); (b)Fe{sup 3+}(A{sub 1}), Fe{sup 3+}(A{sub 2}) and Fe{sup 2+}(B) (BC-2 group), and (c) Fe{sup 3+}(A{sub 1}), Fe{sup 3+}(B) (BC-1 group). The distribution pattern of iron cations at A and B sites was linked to the degree of oxidation. These stages of oxidation could be modelled from normal to inverse form. A model suggesting `electron localisation` at the B-sites makes the intermediate stage. Iron site occupancy determined by Moessbauer spectroscopy of the presently studied samples indicates that these fall under three groups of oxidation stages. An early stage of oxidation is shown by samples of group GC, intermediate stage by group BC-2 and final stage by BC-1 group of chromite samples. The imprint of progressive oxidation manifested by Fe cation site occupancy has been correlated with the Fe{sup 2+}/{Sigma}Fe ratios, obtained for each group of samples. (author). 39 refs., 2 figs., 3 tabs.

Prediction of reducible soil iron content from iron extraction data

NARCIS (Netherlands)

Bodegom, van P.M.; Reeven, van J.; Denier van der Gon, H.A.C.

2003-01-01

Soils contain various iron compounds that differ in solubility, reducibility and extractability. Moreover, the contribution of the various iron compounds to total iron (Fe) and total Fe concentrations differs highly among soils. As a result, the total reducible Fe content can also differ among

Effects of various anesthesia maintenance on serum levels of selenium, copper, zinc, iron and antioxidant capacity

Directory of Open Access Journals (Sweden)

Mehmet Akin

2015-02-01

Full Text Available BACKGROUND AND OBJECTIVES: In this study, we aimed to investigate the effects of sevoflurane, desflurane and propofol maintenances on serum levels of selenium, copper, zinc, iron, malondialdehyde, and glutathion peroxidase measurements, and antioxidant capacity. METHODS: 60 patients scheduled for unilateral lower extremity surgery which would be performed with tourniquet under general anesthesia were divided into three groups. Blood samples were collected to determine the baseline serum levels of selenium, copper, zinc, iron, malondialdehyde and glutathion peroxidase. Anesthesia was induced using 2-2.5 mg kg-1 propofol, 1 mg kg-1 lidocaine and 0.6 mg kg-1 rocuronium. In the maintenance of anesthesia, under carrier gas of 50:50% O2:N2O 4 L min-1, 1 MAC sevoflorane was administered to Group S and 1 MAC desflurane to Group D; and under carrier gas of 50:50% O2:air 4 L min-1 6 mg kg h-1 propofol and 1 µg kg h-1 fentanyl infusion were administered to Group P. At postoperative blood specimens were collected again. RESULTS: It was observed that only in Group S and P, levels of MDA decreased at postoperative 48th hour; levels of glutathion peroxidase increased in comparison to the baseline values. Selenium levels decreased in Group S and Group P, zinc levels decreased in Group P, and iron levels decreased in all three groups, and copper levels did not change in any groups in the postoperative period. CONCLUSION: According to the markers of malondialdehyde and glutathion peroxidase, it was concluded that maintenance of general anesthesia using propofol and sevoflurane activated the antioxidant system against oxidative stress and using desflurane had no effects on oxidative stress and antioxidant system.

Anemia and iron, zinc, copper and magnesium deficiency in Mexican adolescents: National Health and Nutrition Survey 2006 Anemia y deficiencia de hierro, zinc, cobre y magnesio en adolescentes mexicanos: resultados de la ENSANUT 2006

Directory of Open Access Journals (Sweden)

Vanessa De la Cruz-Góngora

2012-04-01

Full Text Available OBJETIVE: To describe the frequency of anemia and iron, zinc, copper and magnesium deficiencies among Mexican adolescents in the probabilistic survey ENSANUT 2006. MATERIALS AND METHODS: The sample included 2447 adolescents aged 12 to 19 y. Capillary hemoglobin and venous blood samples were collected to measure the concentrations of ferritin, sTFR, CRP, zinc, iron, copper and magnesium. Logistic regression models were constructed to assess the risk for mineral deficiencies. RESULTS: The overall prevalence of anemia was 11.8 and 4.6%, body iron deficiency 18.2 and 7.9% for females and males, respectively. Overall prevalence of tissue iron deficiency was 6.9%, low serum copper were14.4 and 12.25%; zinc 28.4 and 24.5%, magnesium 40 and 35.3%; for females and males, respectively. CONCLUSIONS: There is a high prevalence of mineral deficiency in Mexican adolescents; females were more prone to have more mineral deficiencies. Nutritional interventions are necessaries in order to reduce and control them.OBJETIVO: Describir la prevalencia de anemia y deficiencia de hierro, zinc, cobre y magnesio en adolescentes mexicanos en la encuesta probabilística ENSANUT 2006. MATERIAL Y MÉTODOS: La muestra incluyó 2447 adolescentes de 12 a 19 años de edad. Se tomó hemoglobina capilar y muestras de sangre venosa para medir las concentraciones séricas de ferritina, sTFR, CRP, zinc, hierro, cobre y magnesio. Se construyeron modelos de regresión logística para evaluar el riesgo de deficiencia de minerales. RESULTADOS: La prevalencia de anemia fue de 11.8% en mujeres y 4.6% en hombres. Las deficiencias de hierro fueron de 18.2 y 7.9% La deficiencia tisular de hierro fue 6.9%; la baja concentración de cobre fue de 14.4 y 12.25% la de zinc de 28.4 y 24.5%, la de magnesio fue 40 y 35.3% en mujeres y hombres, respectivamente. CONCLUSIONES: Existe una alta prevalencia de deficiencia de minerales en los adolescentes; las mujeres tuvieron mayor riesgo. Son necesarias

Fe(II)/Cu(II) interaction on goethite stimulated by an iron-reducing bacteria Aeromonas Hydrophila HS01 under anaerobic conditions.

Science.gov (United States)

Tao, Liang; Zhu, Zhen-Ke; Li, Fang-Bai; Wang, Shan-Li

2017-11-01

Copper is a trace element essential for living creatures, but copper content in soil should be controlled, as it is toxic. The physical-chemical-biological features of Cu in soil have a significant correlation with the Fe(II)/Cu(II) interaction in soil. Of significant interest to the current study is the effect of Fe(II)/Cu(II) interaction conducted on goethite under anaerobic conditions stimulated by HS01 (a dissimilatory iron reduction (DIR) microbial). The following four treatments were designed: HS01 with α-FeOOH and Cu(II) (T1), HS01 with α-FeOOH (T2), HS01 with Cu(II) (T3), and α-FeOOH with Cu(II) (T4). HS01 presents a negligible impact on copper species transformation (T3), whereas the presence of α-FeOOH significantly enhanced copper aging contributing to the DIR effect (T1). Moreover, the violent reaction between adsorbed Fe(II) and Cu(II) leads to the decreased concentration of the active Fe(II) species (T1), further inhibiting reactions between Fe(II) and iron (hydr)oxides and decelerating the phase transformation of iron (hydr)oxides (T1). From this study, the effects of the Fe(II)/Cu(II) interaction on goethite under anaerobic conditions by HS01 are presented in three aspects: (1) the accelerating effect of copper aging, (2) the reductive transformation of copper, and (3) the inhibition effect of the phase transformation of iron (hydr)oxides. Copyright © 2017 Elsevier Ltd. All rights reserved.

Ionization processes in the Fe 27 region of hot iron plasma in the field of hard gamma radiation

International Nuclear Information System (INIS)

Illarionov, A.F.

1989-01-01

A highly ionized hot plasma of an iron 26 56 Fe-type heavy element in the field of hard ionizing gamma-ray radiation is considered. The processes of ionization and recombination are discussed for a plasma consisting of the fully ionized Fe 27 and the hydrogen-like Fe 26 ions of iron in the case of large optical depth of the plasma with respect to the photoionization by gamma-ray quanta. The self-ionization process of a hot plasma with the temperature kT ≅ I (I being the ionization potential), due to the production of the own ionizing gamma-ray quanta, by the free-free (ff) and recombination (fb) radiation mechanisms, is investigated. It is noted that in the stationary situation the process of self-ionization of a hot plasma imposes the restriction upon the plasma temperature, kT<1.5 I. It is shown that the ionization of heavy-ion plasma by the impact of thermal electrons is dominating over the processes of ff- and fb-selfionization of plasma only by the large concentration of hydrogen-like iron at the periphery of the region of fully ionized iron Fe 27

Assessment of polyphase sintered iron-cobalt-iron boride cermets

International Nuclear Information System (INIS)

Nowacki, J.; Pieczonka, T.

2004-01-01

Sintering of iron, cobalt and boron powders has been analysed. As a result iron-iron boride, Fe-Fe 2 B and iron/cobalt boride with a slight admixture of molybdenum, Fe - Co - (FeMoCo) 2 B cermets have been produced. Iron was introduced to the mixture as the Astalloy Mo Hoeganaes grade powder. Elemental amorphous boron powder was used, and formation of borides occurred both during heating and isothermal sintering periods causing dimensional changes of the sintered body. Dilatometry was chosen to control basic phenomena taking place during multiphase sintering of investigated systems. The microstructure and phase constituents of sintered compacts were controlled as well. The cermets produced were substituted to: metallographic tests, X-ray analysis, measurements of hardness and of microhardness, and of wear in the process of sliding dry friction. Cermets are made up of two phases; hard grains of iron - cobalt boride, (FeCo) 2 B (1800 HV) constituting the reinforcement and a relatively soft and plastic eutectic mixture Fe 2 B - Co (400-500 HV) constituting the matrix. (author)

Serum sample levels of bromine, iron, scandium and zinc in preschool children of Atayal and Bunun aborigines living in central Taiwan

International Nuclear Information System (INIS)

Chien-Yi Chen; Ding-Bang Lin; Yuan-Yaw Wei

2006-01-01

This study determined bromine, iron, scandium and zinc serum levels in Taiwanese aboriginal preschool children living in remote mountainous areas to increase the understanding of the social, cultural, nutrient and ethnic background of the Taiwanese children. Seventy-three serum samples were taken from two ethnic groups of preschool children, Atayal aborigines (AAPC) and Bunun aborigines (BAPC). Sera of these children were freeze dried. Trace elements in sera were identified by instrumental neutron activation analysis (INAA). The accuracy and precision of INAA was evaluated using certified reference materials: Tomato Leaves (NIST-SRM 1570a) and Lichen (IAEA-336). Statistical analysis identified several different patterns for ethnic groups, gender and age via the two-tailed Student's t-test. Analytical results showed that the ranges of Br, Fe, Sc and Zn in sera were somewhat wide. The Zn serum levels (p < 0.05) and Br serum levels (p < 0.01) in the AAPC were significantly lower than those in the BAPC. However, there were no significant differences in Fe or Sc serum levels between the two groups. Analytical results were compared to published data for different counties. This study is the first investigating trace elements in Taiwanese aborigines and can be used to establish a much-needed serum element database. (author)

Iodine as an oxidant in the topotactic deintercalation of interstitial iron in Fe(1+x)Te.

Science.gov (United States)

Rodriguez, Efrain E; Zavalij, Peter; Hsieh, Ping-Yen; Green, Mark A

2010-07-28

The layered telluride, Fe(1+x)Te, is a parent compound of the isostructural and superconducting phases, Fe(1+x)(Te, Se, S). Here we show that, through a simple reaction of I(2) vapor with both powder and single crystal samples, the interstitial iron can be removed from the FeTe framework topotactically. Neutron powder diffraction and X-ray single crystal diffraction confirm that the iron being extracted is the partially occupied site that lies between the 2-D blocks of edge-sharing FeTe(4) tetrahedra. The deintercalation process has consequences for both magnetic and crystallographic phase transitions in the compound at low temperatures. This technique could be of use for the tuning of stoichiometry of the superconducting phases and therefore enable more careful studies on how chemical composition affects magnetic and superconducting properties.

Co-ordinated research programme on isotope-aided studies of the bioavailability of iron and zinc from human diets

International Nuclear Information System (INIS)

1992-01-01

Nutritional deficiencies of essential micronutrients (particularly of iron, but also of zinc and selenium) are known to affect hundreds of millions of people throughout the world, mainly in developing countries. Such deficiencies can lead to significant deficits in mental development, growth, work performance, immune competence and other biological parameters. In many of the population groups that are affected, the deficiencies are thought to be due not to an absolute lack of the element in the diet but rather to is poor bioavailability. Much work has already been done on this subject, particularly in some developed countries and particularly with respect to iron. However, there is still appears to be a need for more research on factors affecting bioavailability and the means to improve it by simple dietary modification and fortification using food products of the kind that may be locally available in developing countries. Isotope techniques potentially have a large role to play in studies of the bioavailability of iron and other trace elements. To support work in this area, the IAEA initiated a Co-ordinated Research Programme (CRP) at the end of 1990 on ''Isotope-Aided Studies of the Bioavailability of Iron and Zinc from Human Diets''. The first Research Co-ordination Meeting (RCM) of participants in this CRP is the subject of the present report. Refs, figs and tabs

Preparation and chemical stability of iron-nitride-coated iron microparticles

International Nuclear Information System (INIS)

Luo Xin; Liu Shixiong

2007-01-01

Iron-nitride-coated iron microparticles were prepared by nitridation of the surface of iron microparticles with ammonia gas at a temperature of 510 deg. C. The phases, composition, morphology, magnetic properties, and chemical stability of the particles were studied. The phases were α-Fe, ε-Fe 3 N, and γ-Fe 4 N. The composition varied from the core to the surface, with 99.8 wt% Fe in the core, and 93.8 wt% Fe and 6 wt% N in the iron-nitride coating. The thickness of the iron-nitride coating was about 0.28 μm. The chemical stability of the microparticles was greatly improved, especially the corrosion resistance in corrosive aqueous media. The saturation magnetization and the coercive force were 17.1x10 3 and 68 kA/m, respectively. It can be concluded that iron-nitride-coated iron microparticles will be very useful in many fields, such as water-based magnetorheological fluids and polishing fluids

Characterising the reactivity of metallic iron in Fe 0 /As-rock/H 2 O ...

African Journals Online (AJOL)

The intrinsic reactivity of 4 metallic iron materials (Fe0) was investigated in batch and column experiments. The Fe0 reactivity was characterised by the extent of aqueous fixation of in-situ leached arsenic (As). Air-homogenised batch experiments were conducted for 1 month with 10.0 g/. of an As-bearing rock (ore material) ...

Microstructure and properties of multiphase sintered cermets Fe-Fe2B

International Nuclear Information System (INIS)

Nowacki, J.; Klimek, L.

1998-01-01

The process of multiphase sintering of iron in the vacuum has been analysed. As a result of the process iron-iron boride cermets have been produced. Fe-Fe 2 B cermets were obtained as a result of sintering of the Fe and B pure elements in the vacuum. Attemps at sintering in the solid phase and with the participation of the liquid phase, the Fe-Fe 2 B eutectic, have been made. Metallographic qualitative and quantitative studies, X-ray structural qualitative and qauantitative analysis allowed to determine the structure of Fe 2 B cermets, as well as a description of the kinetics of quantitative changes in phase proportions in the course of sintering. It has been found that their structure varies widely depending on sintering parameters and the composition of the sinters. Measurements of the Fe-Fe 2 B cermets hardness and measurements on wear during dry friction by the pin-on-disc method have shown distinct advantages of the cermets as a modern constructional materials. The hardness of Fe-Fe 2 B cermets, depending on their chemical composition and sintering parameters, ranges widely from 150 to 1500 HV, and their resistance to wear is comparable to that of diffusively boronized steels. FeFe 2 B cermets are a composite material in which iron boride, Fe 2 B, with a hardness of about 1800 HV plays the role of the reinforcement,while iron-iron boride, Fe-Fe 2 B, with a hardness of about 500 HV plays the role of matrix. The eutectic in the spaces between iron boride grains is composed of boron solid solution plates in iron with a hardness of arround 250 HV, and iron boride, Fe 2 B, plates with a hardness of approximaly 1800 HV. The combination of such different materials, a hard reinforcement and a relatively plastic matrix produces favourable properties of the cermet thus produced high hardness (1500 HV) constant over whole cross section of the material, resistance of abrasive wear and acceptable ductility. The properties mentioned above, resulting from the cermet

Absorption and translocation of 59Fe and 14C-rhodotorulate in iron-stressed tomato

International Nuclear Information System (INIS)

Miller, G.W.; Shigematsu, A.; Motoji, N.; Shibabe, S.

1990-01-01

Tomato plants, cultivars FER and Earlygirl (both iron efficient and able to use rhodotorulate- 59 Fe), were grown under low Fe conditions for 9 days. Rhodotorulate- 14 C, isolated from Rhodotorula pilimanae cultured with 14 C-sucrose, and rhodotorulate- 59 Fe were added to the Fe-stressed plants for 6-, 24- or 48-h periods. It was evident from autoradiograms and tissue sampling that 59 Fe and 14 C were abundant in roots, stems and leaves. The 14 C autoradiograms showed especially high density in the small, younger leaves, as was found also with 59 Fe. Unlike synthetic chelates, rhodotorulate (or metabolised derivatives) was readily absorbed by the roots and translocated to the leaves. (author)

Efficacy of a microencapsulated iron pyrophosphate-fortified fruit juice: a randomised, double-blind, placebo-controlled study in Spanish iron-deficient women.

Science.gov (United States)

Blanco-Rojo, Ruth; Pérez-Granados, Ana M; Toxqui, Laura; González-Vizcayno, Carmen; Delgado, Marco A; Vaquero, M Pilar

2011-06-01

Fe-deficiency anaemia is a worldwide health problem. We studied the influence of consuming an Fe-fortified fruit juice on Fe status in menstruating women. A randomised, double-blind, placebo-controlled study of 16 weeks of duration was performed. Subjects were randomised into two groups: the P group (n 58) or the F group (n 64), and consumed, as a supplement to their usual diet, 500 ml/d of a placebo fruit juice or an Fe-fortified fruit juice, respectively. The Fe-fortified fruit juice, containing microencapsulated iron pyrophosphate, provided 18 mg Fe/d (100 % of the RDA). At baseline and monthly, dietary intake, body weight and Fe parameters were determined: total erythrocytes, haematocrit, mean corpuscular volume (MCV), red blood cell distribution width (RDW), Hb, serum Fe, serum ferritin, serum transferrin, transferrin saturation, soluble transferrin receptor (sTfR) and zinc protoporphyrin (ZnPP). The fruit juice consumption involved increased intake of carbohydrates and vitamin C, and increased BMI within normal limits. Ferritin was higher in the F group after week 4 (P juice improves Fe status and may be used to prevent Fe-deficiency anaemia.

Environmental application of millimetre-scale sponge iron (s-Fe{sup 0}) particles (III): The effect of surface silver

Energy Technology Data Exchange (ETDEWEB)

Ju, Yongming [South China Institute of Environmental Sciences, Ministry of Environmental Protection (MEP), Guangzhou 510655 (China); South China Subcenter of State Environmental Dioxin Monitoring Center, Guangzhou 510655 (China); Innovative Laboratory for Environmental Functional Materials and Environmental Applications of Microwave Irradiation, Guangzhou 510655 (China); Yu, Yunjiang, E-mail: yuyunjiang@scies.org [South China Institute of Environmental Sciences, Ministry of Environmental Protection (MEP), Guangzhou 510655 (China); Wang, Xiaoyan [South China Institute of Environmental Sciences, Ministry of Environmental Protection (MEP), Guangzhou 510655 (China); Innovative Laboratory for Environmental Functional Materials and Environmental Applications of Microwave Irradiation, Guangzhou 510655 (China); Zhang, Sukun [South China Institute of Environmental Sciences, Ministry of Environmental Protection (MEP), Guangzhou 510655 (China); Liu, Runlong [South China Institute of Environmental Sciences, Ministry of Environmental Protection (MEP), Guangzhou 510655 (China); Innovative Laboratory for Environmental Functional Materials and Environmental Applications of Microwave Irradiation, Guangzhou 510655 (China); Fu, Jianping; Han, Jinglei; Fang, Jiande [South China Institute of Environmental Sciences, Ministry of Environmental Protection (MEP), Guangzhou 510655 (China); Dionysiou, Dionysios D., E-mail: dionysios.d.dionysiou@uc.edu [Environmental Engineering and Science Program, Department of Biomedical, Chemical and Environmental Engineering (DBCEE), University of Cincinnati, Cincinnati, OH 45221-0012 (United States)

2015-12-15

Highlights: • Direct reductive deposition reaction achieves surfaced decoration of s-Fe{sup 0} particles. • Ag{sup 0}-s-Fe{sup 0} displays similar removal efficiency of PCP as compared to bimetal of nZVI. • Ag{sup 0}-s-Fe{sup 0} can be utilized under mild reaction condition compared to bimetal of nZVI. • The catalytic mechanism over Ag{sup 0}-s-Fe{sup 0} under US condition is elucidated. - Abstract: To enhance the dechlorination reactivity of millimetric sponge iron (s-Fe{sup 0}), a facile one-pot method was used to decorate s-Fe{sup 0} with Ag{sup +} ions under ambient conditions. The results recorded by X-ray diffraction patterns, X-ray photoelectron spectra and high-resolution transmission electron microscopy demonstrated that the growth of Ag{sup 0} was dominated primarily by (1 1 1) plane with a mean length of ∼20 nm. The roles of Ag{sup 0} loading, catalyst dosage, particle size, initial pH and contaminant concentration were assessed during the removal of pentachlorophenol (PCP). Catalyst recyclability was also studied. The results revealed that 3–5 mm s-Fe{sup 0} particles with 5 wt% Ag{sup 0} loading exhibited the best performance with a dose of 3.0 g per 60 mL PCP solution. In addition, the dechlorination of PCP followed two-step, pseudo-first-order reaction kinetics, and Ag{sup 0}-s-Fe{sup 0} was advantageous compared with bimetals of nanoscale zero-valent iron, iron power and iron flakes. The dechlorination mechanism of PCP over Ag{sup 0}-s-Fe{sup 0} was attributed to the surface Ag{sup 0} decoration, which catalyzed the formation of reactive hydrogen atoms for indirect reaction, and the direct electron transfer via Fe–Ag{sup 0} galvanic cells for direct reaction. This suggests that Ag-based bimetals of s-Fe{sup 0} have great potential in the pretreatment of organic halogen compounds in aqueous solution.

Experimental observation of zinc dialkyl dithiophosphate (ZDDP)-induced iron sulphide formation

Energy Technology Data Exchange (ETDEWEB)

Soltanahmadi, Siavash, E-mail: s.soltanahmadi@leeds.ac.uk [Institute of Functional Surfaces, School of Mechanical Engineering, University of Leeds, LS2 9JT (United Kingdom); Morina, Ardian [Institute of Functional Surfaces, School of Mechanical Engineering, University of Leeds, LS2 9JT (United Kingdom); Eijk, Marcel C.P. van; Nedelcu, Ileana [SKF Engineering and Research Centre, 3430 DT Nieuwegein (Netherlands); Neville, Anne [Institute of Functional Surfaces, School of Mechanical Engineering, University of Leeds, LS2 9JT (United Kingdom)

2017-08-31

Graphical abstract: Chemical analysis of ZDDP-induced tribofilm under severe boundary lubricated regime in nano and micro-meter scales.▪ - Highlights: • A ZDDP-derived locally formed iron-sulphide layer is detected on the steel surface. • The iron-sulphide is a 5–10 nm thin distinct layer at steel-phosphate interface. • Near the surface-crack site the elemental distribution of the tribofilm is altered. • Sulphur concentration is enhanced in the iron-sulphide layer near the cracked-site. • ZDDP elements are detected inside the crack with a greater contribution of sulphur. - Abstract: Zinc dialkyl dithiophosphate (ZDDP) as a well-known anti-wear additive enhances the performance of the lubricant beyond its wear-protection action, through its anti-oxidant and Extreme Pressure (EP) functionality. In spite of over thirty years of research attempting to reveal the mechanism of action of ZDDP, there are still some uncertainties around the exact mechanisms of its action. This is especially the case with the role of sulphide layer formed in the tribofilm and its impact on surface fatigue. Although iron sulphide on the substrate is hypothesised in literature to form as a separate layer, there has been no concrete experimental observation on the distribution of the iron sulphide as a dispersed precipitate, distinct layer at the steel substrate or both. It remains to be clarified whether the iron sulphide layer homogeneously covers the surface or locally forms at the surface. In the current study a cross section of the specimen after experiment was prepared and has been investigated with Transmission Electron Microscopy (TEM) and Energy-Dispersive X-ray (EDX) elemental analysis. A 5–10 nm iron sulphide layer is visualised on the interface as a separate layer underneath the phosphate layer with an altered distribution of tribofilm elements near the crack site. The iron sulphide interface layer is more visible near the crack site where the concentration of the

Experimental observation of zinc dialkyl dithiophosphate (ZDDP)-induced iron sulphide formation

International Nuclear Information System (INIS)

Soltanahmadi, Siavash; Morina, Ardian; Eijk, Marcel C.P. van; Nedelcu, Ileana; Neville, Anne

2017-01-01

Graphical abstract: Chemical analysis of ZDDP-induced tribofilm under severe boundary lubricated regime in nano and micro-meter scales.▪ - Highlights: • A ZDDP-derived locally formed iron-sulphide layer is detected on the steel surface. • The iron-sulphide is a 5–10 nm thin distinct layer at steel-phosphate interface. • Near the surface-crack site the elemental distribution of the tribofilm is altered. • Sulphur concentration is enhanced in the iron-sulphide layer near the cracked-site. • ZDDP elements are detected inside the crack with a greater contribution of sulphur. - Abstract: Zinc dialkyl dithiophosphate (ZDDP) as a well-known anti-wear additive enhances the performance of the lubricant beyond its wear-protection action, through its anti-oxidant and Extreme Pressure (EP) functionality. In spite of over thirty years of research attempting to reveal the mechanism of action of ZDDP, there are still some uncertainties around the exact mechanisms of its action. This is especially the case with the role of sulphide layer formed in the tribofilm and its impact on surface fatigue. Although iron sulphide on the substrate is hypothesised in literature to form as a separate layer, there has been no concrete experimental observation on the distribution of the iron sulphide as a dispersed precipitate, distinct layer at the steel substrate or both. It remains to be clarified whether the iron sulphide layer homogeneously covers the surface or locally forms at the surface. In the current study a cross section of the specimen after experiment was prepared and has been investigated with Transmission Electron Microscopy (TEM) and Energy-Dispersive X-ray (EDX) elemental analysis. A 5–10 nm iron sulphide layer is visualised on the interface as a separate layer underneath the phosphate layer with an altered distribution of tribofilm elements near the crack site. The iron sulphide interface layer is more visible near the crack site where the concentration of the

The Suitability of Zn–1.3%Fe Alloy as a Biodegradable Implant Material

Directory of Open Access Journals (Sweden)

Alon Kafri

2018-02-01

Full Text Available Efforts to develop metallic zinc for biodegradable implants have significantly advanced following an earlier focus on magnesium (Mg and iron (Fe. Mg and Fe base alloys experience an accelerated corrosion rate and harmful corrosion products, respectively. The corrosion rate of pure Zn, however, may need to be modified from its reported ~20 µm/year penetration rate, depending upon the intended application. The present study aimed at evaluating the possibility of using Fe as a relatively cathodic biocompatible alloying element in zinc that can tune the implant degradation rate via microgalvanic effects. The selected Zn–1.3wt %Fe alloy composition produced by gravity casting was examined in vitro and in vivo. The in vitro examination included immersion tests, potentiodynamic polarization and impedance spectroscopy, all in a simulated physiological environment (phosphate-buffered saline, PBS at 37 °C. For the in vivo study, two cylindrical disks (seven millimeters diameter and two millimeters height were implanted into the back midline of male Wister rats. The rats were examined post implantation in terms of weight gain and hematological characteristics, including red blood cell (RBC, hemoglobin (HGB and white blood cell (WBC levels. Following retrieval, specimens were examined for corrosion rate measurements and histological analysis of subcutaneous tissue in the implant vicinity. In vivo analysis demonstrated that the Zn–1.3%Fe implant avoided harmful systemic effects. The in vivo and in vitro results indicate that the Zn–1.3%Fe alloy corrosion rate is significantly increased compared to pure zinc. The relatively increased degradation of Zn–1.3%Fe was mainly related to microgalvanic effects produced by a secondary Zn11Fe phase.

Isotope aided studies of the bioavailability of iron and zinc from human diets consumed in Venezuela

International Nuclear Information System (INIS)

Layrisse, M.A.

1994-01-01

Previous studies on Venezuelan diets provided information on food consumed in each diet and their nutritional contents. It also showed the comparison of the iron absorption from these diets when given in the morning after over-night fast and when given at the customary time of the day. It was observed that the iron absorption from the lunch given at noon was slightly higher (although not significant) in Zulia and Sucre diets. There were no significant differences between the Zulia lunch given in the morning after over-night fast at noon. Similar results were observed in the Sucre diet lunch repeated twice. From these results we can state that iron absorption from meals is not affected by the time it is administered with the condition that the subjects tested have had a previous fast of three hours before the meal is administered. The significant difference in iron absorption in the first study could be due to a marked physiological daily variation in iron absorption. The results from these studies provide credit to previous reports in which meals were given in the morning after an over-night fast. The iron absorption studies from 11 diets consumed by the Venezuelan population, provided the basic information for the establishment of a programme on iron fortification. The Government of Venezuela, according to the recommendation of the National Nutrition Institute, approved a national programme of iron fortification by enriching precooked maize flour with ferrous fumarate in the proportion of 5 mg Fe/100 g flour, and the enrichment of flour used to produce paste with the same iron compound in the proportion of 3 mg Fe/100 g flour. This year, the Chemical Centre of the Venezuela Scientific Institute of Research discovered an iron compound, now called FERROIVIC. It is an insoluble white powder that, when given as iron fortification, forms part of the nonhaeme iron pool and it is absorbed to the same extent as ferrous sulphate; it is stable for several months. 15 refs, 8

LiFePO4 Nanostructures Fabricated from Iron(III) Phosphate (FePO4 x 2H2O) by Hydrothermal Method.

Science.gov (United States)

Saji, Viswanathan S; Song, Hyun-Kon

2015-01-01

Electrode materials having nanometer scale dimensions are expected to have property enhancements due to enhanced surface area and mass/charge transport kinetics. This is particularly relevant to intrinsically low electronically conductive materials such as lithium iron phosphate (LiFePO4), which is of recent research interest as a high performance intercalation electrode material for Li-ion batteries. Many of the reported works on LiFePO4 synthesis are unattractive either due to the high cost of raw materials or due to the complex synthesis technique. In this direction, synthesis of LiFePO4 directly from inexpensive FePO4 shows promise.The present study reports LiFePO4 nanostructures prepared from iron (III) phosphate (FePO4 x 2H2O) by precipitation-hydrothermal method. The sintered powder was characterized by X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS), Inductive coupled plasma-optical emission spectroscopy (ICP-OES), and Electron microscopy (SEM and TEM). Two synthesis methods, viz. bulk synthesis and anodized aluminum oxide (AAO) template-assisted synthesis are reported. By bulk synthesis, micro-sized particles having peculiar surface nanostructuring were formed at precipitation pH of 6.0 to 7.5 whereas typical nanosized LiFePO4 resulted at pH ≥ 8.0. An in-situ precipitation strategy inside the pores of AAO utilizing the spin coating was utilized for the AAO-template-assisted synthesis. The template with pores filled with the precipitate was subsequently subjected to hydrothermal process and high temperature sintering to fabricate compact rod-like structures.

Extreme Ultraviolet Emission Lines of Iron Fe XI-XIII

Science.gov (United States)

Lepson, Jaan; Beiersdorfer, P.; Brown, G. V.; Liedahl, D. A.; Brickhouse, N. S.; Dupree, A. K.

2013-04-01

The extreme ultraviolet (EUV) spectral region (ca. 20--300 Å) is rich in emission lines from low- to mid-Z ions, particularly from the middle charge states of iron. Many of these emission lines are important diagnostics for astrophysical plasmas, providing information on properties such as elemental abundance, temperature, density, and even magnetic field strength. In recent years, strides have been made to understand the complexity of the atomic levels of the ions that emit the lines that contribute to the richness of the EUV region. Laboratory measurements have been made to verify and benchmark the lines. Here, we present laboratory measurements of Fe XI, Fe XII, and Fe XIII between 40-140 Å. The measurements were made at the Lawrence Livermore electron beam ion trap (EBIT) facility, which has been optimized for laboratory astrophysics, and which allows us to select specific charge states of iron to help line identification. We also present new calculations by the Hebrew University - Lawrence Livermore Atomic Code (HULLAC), which we also utilized for line identification. We found that HULLAC does a creditable job of reproducing the forest of lines we observed in the EBIT spectra, although line positions are in need of adjustment, and line intensities often differed from those observed. We identify or confirm a number of new lines for these charge states. This work was supported by the NASA Solar and Heliospheric Program under Contract NNH10AN31I and the DOE General Plasma Science program. Work was performed in part under the auspices of the Department of Energy by Lawrence Livermore National Laboratory under Contract DEAC52-07NA27344.

Characterizing the production and retention of dissolved iron as Fe(II) across a natural gradient in chlorophyll concentrations in the Southern Drake Passage - Final Technical Report

Energy Technology Data Exchange (ETDEWEB)

Katherine Barbeau

2007-04-10

Recent mesoscale iron fertilization studies in the Southern Ocean (e.g. SOIREE, EisenEx, SOFeX) have demonstrated the importance of iron as a limiting factor for phytoplankton growth in these high nutrient, low-chlorophyll (HNLC) waters. Results of these experiments have demonstrated that factors which influence the biological availability of the iron supplied to phytoplankton are crucial in bloom development, longevity, and generation of carbon export flux. These findings have important implications for the future development of iron fertilization protocols to enhance carbon sequestration in high-latitude oceans. In particular, processes which lead to the mobilization and retention of iron in dissolved form in the upper ocean are important in promoting continued biological availability of iron. Such processes can include photochemical redox cycling, which leads to the formation of soluble reduced iron, Fe(II), within iron-enriched waters. Creation of effective fertilization schemes will thus require more information about Fe(II) photoproduction in Southern Ocean waters as a means to retain new iron within the euphotic zone. To contribute to our knowledge base in this area, this project was funded by DOE with a goal of characterizing the production and retention of dissolved Fe as Fe(II) in an area of the southern Drake Passage near the Shackleton Transverse Ridge, a region with a strong recurrent chlorophyll gradient which is believed to be a site of natural iron enrichment in the Southern Ocean. This area was the focus of a multidisciplinary NSF/OPP-funded investigation in February 2004 (OPP02-30443, lead PI Greg Mitchell, SIO/UCSD) to determine the influence of mesoscale circulation and iron transport with regard to the observed patterns in sea surface chlorophyll in the region near the Shackleton Transverse Ridge. A number of parameters were assessed across this gradient in order to reveal interactions between plankton community structure and iron distributions

Cadmium uptake by and translocation within rice (oryza sativa l.) seedlings as affected by iron plaque and Fe/sub 2/O/sub 3/

International Nuclear Information System (INIS)

Lai, Y.; Xu, B.O.; Mou, S.

2012-01-01

A hydroponics culture experiment was carried out to investigate the effect of iron plaque and/or Fe/sub 2/O/sub 3/ on Cadmium (Cd) uptake by and translocation within rice seedlings. Uniform rice seedlings grown in nutrient solution for two weeks were selected and transferred to nutrient solution containing ferrous iron (Fe/sup 2+/) (30 mg/L) for 24 h to induce the formation of iron plaque on the root surface. Then rice seedlings were exposed to different level of Cd (1.0 mg/L and 0.1 mg/L), and simultaneously Fe/sub 2/O/sub 3/ was added into hydroponic system for three days. At harvest Cd content in dithionite-citrate-bicarbonate (DCB) extracts, roots and shoots were determined. The results of this study showed that iron plaque could sequester more Cd on root surfaces of rice seedlings, however, Fe/sub 2/O/sub 3/ reduced Cd adsorbed on root surfaces. Both of iron plaque and/or Fe/sub 2/O/sub 3/ did not block Cd uptake by and translocation within rice seedlings. Although iron plaque could alleviate Cd toxicity to rice seedlings under low concentration of Cd (0.1 mg/L), the root tissue played more important role in reducing Cd translocation into shoot. And the long period experiment of hydroponic and soil culture was still needed to verify the potential effect of iron plaque and/or Fe/sub 2/O/sub 3/ on alleviating Cd toxicity to rice seedlings. (author)

Effects of soil and foliar applications of iron and zinc on flowering and essential oil of chamomile at greenhouse conditions

Directory of Open Access Journals (Sweden)

Yousef NASIRI

2015-11-01

Full Text Available In order to study the effects of soil and foliar applications of iron (Fe and zinc (Zn on flowering, flower yield and essential oil production of German chamomile a pot experiment was conducted under greenhouse conditions at the Faculty of Agriculture, University of Tabriz, Iran in 2012. The experiment was arranged as completely randomized design with 12 treatments and three replications. Treatments were as follow: T1: control – without Fe or Zn fertilizers, T2: 30 mg FeSO4.7H2O kg-1 dry soil, T3: 22 mg ZnSO4.7H2O kg-1 dry soil, T4: 30 mg FeSO4.7H2O + 22 mg ZnSO4.7H2O kg-1 dry soil, T5: foliar spraying of FeSO4.7H2O (3.5 g L-1, T6: foliar spraying of FeSO4.7H2O (7.0 g L-1, T7: foliar spraying of ZnSO4.7H2O (2.5 g L-1, T8: foliar spraying of ZnSO4.7H2O (5.0 g L-1, T9: T5+T7, T10: T5+T8, T11: T6+T7, T12: T6+T8. The foliar spraying was done two times during the growing period. The results revealed that the flower number, flower yield, essential oil content and essential oil yield were significantly increased by soil and foliar applications of Fe + Zn, compared with the control (untreated. The highest flower number (477 plant-1, flower yield (11.6 g pot-1, essential oil content (0.88 % and essential oil yield (119 mg pot-1 were recorded for the soil application of Fe + Zn (T4 by 58, 68, 21.4 and 105 % increment compared to the control, respectively. Foliar application of Fe + Zn (T12 was placed at the next rank; however this treatment had no significant difference with the soil application of Fe + Zn (T4. Other treatments did not show significant differences with the control. Generally, the results showed that soil or foliar application of Fe + Zn can be effective on increase or improve of quantity and quality of chamomile yield. Moreover, use of foliar application as a low cost method especially in areas with alkaline or calcareous soils can be recommended.

Serum iron test

Science.gov (United States)

Fe+2; Ferric ion; Fe++; Ferrous ion; Iron - serum; Anemia - serum iron; Hemochromatosis - serum iron ... A blood sample is needed. Iron levels are highest in the morning. Your health care provider will likely have you do this test in the morning.

Synthesis, characterization and performance in arsenic removal of iron-doped activated carbons prepared by impregnation with Fe(III) and Fe(II)

International Nuclear Information System (INIS)

Muniz, G.; Fierro, V.; Celzard, A.; Furdin, G.; Gonzalez-Sanchez, G.; Ballinas, M.L.

2009-01-01

Arsenic removal from natural well water from the state of Chihuahua (Mexico) is investigated by adsorption using a commercial activated carbon (AC). The latter is used as such, or after oxidation by several chemicals in aqueous solution: nitric acid, hydrogen peroxide, and ammonium persulphate. Raw and oxidised activated carbons are fully characterised (elementary analysis, surface chemistry, pore texture parameters, pH ZC , and TEM observation). Adsorption of As is measured in the aforementioned water, containing ca. 300 ppb of arsenic: removal of As is poor with the raw AC, and only the most oxidised carbons exhibit higher performances. By contrast, iron-doped ACs are much more efficient for that purpose, though their As uptake strongly depends on their preparation conditions: a number of samples were synthesised by impregnation of raw and oxidised ACs with HCl aqueous solutions of either FeCl 3 or FeCl 2 at various concentrations and various pH. It is shown that iron(II) chloride is better for obtaining high iron contents in the resultant ACs (up to 8.34 wt.%), leading to high As uptake, close to 0.036 mg As/g C. In these conditions, 100% of the As initially present in the natural well water is removed, as soon as the Fe content of the adsorbent is higher than 2 wt.%.

A review of phytate, iron, zinc, and calcium concentrations in plant-based complementary foods used in low-income countries and implications for bioavailability.

Science.gov (United States)

Gibson, Rosalind S; Bailey, Karl B; Gibbs, Michelle; Ferguson, Elaine L

2010-06-01

Plant-based complementary foods often contain high levels of phytate, a potent inhibitor of iron, zinc, and calcium absorption. This review summarizes the concentrations of phytate (as hexa- and penta-inositol phosphate), iron, zinc, and calcium and the corresponding phytate:mineral molar ratios in 26 indigenous and 27 commercially processed plant-based complementary foods sold in low-income countries. Phytate concentrations were highest in complementary foods based on unrefined cereals and legumes (approximately 600 mg/100 g dry weight), followed by refined cereals (approximately 100 mg/100 g dry weight) and then starchy roots and tubers (source foods and/or fortification with minerals. Dephytinization, either in the household or commercially, can potentially enhance mineral absorption in high-phytate complementary foods, although probably not enough to overcome the shortfalls in iron, zinc, and calcium content of plant-based complementary foods used in low-income countries. Instead, to ensure the World Health Organization estimated needs for these minerals from plant-based complementary foods for breastfed infants are met, dephytinization must be combined with enrichment with animal-source foods and/or fortification with appropriate levels and forms of mineral fortificants.

In Vitro Bioavailability of Calcium, Magnesium, Iron, Zinc, and Copper from Gluten-Free Breads Supplemented with Natural Additives.

Science.gov (United States)

Regula, J; Cerba, A; Suliburska, J; Tinkov, A A

2018-03-01

The aim of this study was to measure the content of calcium, magnesium, iron, zinc, and copper and determine the bioavailability of these ingredients in gluten-free breads fortified with milk and selected seeds. Due to the increasing prevalence of celiac disease and mineral deficiencies, it has become necessary to produce food with higher nutritional values which maintains the appropriate product characteristics. This study was designed for gluten-free breads fortified with milk and seeds such as flax, poppy, sunflower seeds, pumpkin seeds or nuts, and flour with amaranth. Subsequently, digestion was performed in vitro and the potential bioavailability of the minerals was measured. In the case of calcium, magnesium, iron, and copper, higher bioavailability was observed in rice bread, and, in the case of copper and zinc, in buckwheat bread. This demonstrated a clear increase in bioavailability of all the minerals when the bread were enriched. However, satisfactory results are obtained only for the individual micronutrients.

Phase composition of iron-rich R-Fe-Si (R=Dy, Ho, Er) alloys

International Nuclear Information System (INIS)

Ivanova, G.V.; Makarova, G.M.; Shcherbakova, E.V.; Belozerov, E.V.

2005-01-01

Phase composition is studied in iron-rich alloys of R-Fe-Si (R=Dy, Ho, Er). In the as-cast state R 2 (Fe, Si) 17 of type Th 2 Ni 17 and R(Fe, Si) 12 compounds are observed; in the alloys of rated composition of R(Fe 0.85 Si 0.15 ) 8.5 (R=Dy, Er) a compound R 2 (Fe, Si) 17 of Th 2 Zn 17 -type is revealed as well. The annealing at 1273 K results in formation of Dy 3 (Fe, Si) 29 and also the compounds with the presumed composition of Dy 4 (Fe, Si) 41 and Ho 4 (Fe, Si) 41 . As this takes place the alloys contain a transition structure as well that represents a set of small-sized areas with various type short-range order in mutual displacement of Fe-Fe(Si) dumpbell chains. The process of phase formation at 1273 K is faced with difficulties. Even the annealing for 1000 h does not result in the state of equilibrium [ru

Iron Supply Affects Anthocyanin Content and Related Gene Expression in Berries of Vitis vinifera cv. Cabernet Sauvignon.

Science.gov (United States)

Shi, Pengbao; Li, Bing; Chen, Haiju; Song, Changzheng; Meng, Jiangfei; Xi, Zhumei; Zhang, Zhenwen

2017-02-14

Anthocyanins are important compounds for red grape and red wine quality, and can be influenced by supply of nutrients such as nitrogen, phosphorus, potassium, zinc, and iron. The present work aims to gain a better understanding of the effect of iron supply on anthocyanins concentration in grape berries. To this end, own-rooted four-year-old Cabernet Sauvignon grapevines ( Vitis vinifera ) were fertigated every three days with 0, 23, 46, 92, and 184 μM iron (Fe) from ferric ethylenediamine di ( o -hydroxyphenylacetic) acid (Fe-EDDHA) in a complete nutrient solution. Fe deficiency or excess generally led to higher concentrations of titratable acidity and skin/berry ratio, and to lower reducing sugar content, sugar/acid ratio, pH, berry weight, and concentration of anthocyanins. Most of the individual anthocyanins detected in this study, except cyanidin-3- O -glucoside, delphinidin-3- O -glucoside, and cyanidin-3- O -(6- O -coumaryl)-glucoside, in moderate Fe treatment (46 μM) grapes were significantly higher than those of other treatments. Genes encoding chalcone isomerase (CHI), flavanone 3-hydroxylase (F3H), leucoanthocyanidin dioxygenase (LDOX), and anthocyanin O -methyltransferase (AOMT) exhibited higher transcript levels in berries from plants cultivated with 46 μM Fe compared to the ones cultivated with other Fe concentrations. We suggest that grape sugar content, anthocyanins content, and transcriptions of genes involved in anthocyanin biosynthesis were correlated with Fe supply concentrations.

Phase diagram of (Li(1-x)Fe(x))OHFeSe: a bridge between iron selenide and arsenide superconductors.

Science.gov (United States)

Dong, Xiaoli; Zhou, Huaxue; Yang, Huaixin; Yuan, Jie; Jin, Kui; Zhou, Fang; Yuan, Dongna; Wei, Linlin; Li, Jianqi; Wang, Xinqiang; Zhang, Guangming; Zhao, Zhongxian

2015-01-14

Previous experimental results have shown important differences between iron selenide and arsenide superconductors which seem to suggest that the high-temperature superconductivity in these two subgroups of iron-based families may arise from different electronic ground states. Here we report the complete phase diagram of a newly synthesized superconducting (SC) system, (Li1-xFex)OHFeSe, with a structure similar to that of FeAs-based superconductors. In the non-SC samples, an antiferromagnetic (AFM) spin-density-wave (SDW) transition occurs at ∼127 K. This is the first example to demonstrate such an SDW phase in an FeSe-based superconductor system. Transmission electron microscopy shows that a well-known √5×√5 iron vacancy ordered state, resulting in an AFM order at ∼500 K in AyFe2-xSe2 (A = metal ions) superconductor systems, is absent in both non-SC and SC samples, but a unique superstructure with a modulation wave vector q = (1)/2(1,1,0), identical to that seen in the SC phase of KyFe2-xSe2, is dominant in the optimal SC sample (with an SC transition temperature Tc = 40 K). Hence, we conclude that the high-Tc superconductivity in (Li1-xFex)OHFeSe stems from the similarly weak AFM fluctuations as FeAs-based superconductors, suggesting a universal physical picture for both iron selenide and arsenide superconductors.

Iron-binding haemerythrin RING ubiquitin ligases regulate plant iron responses and accumulation

Science.gov (United States)

Kobayashi, Takanori; Nagasaka, Seiji; Senoura, Takeshi; Itai, Reiko Nakanishi; Nakanishi, Hiromi; Nishizawa, Naoko K.

2013-01-01

Iron is essential for most living organisms. Plants transcriptionally induce genes involved in iron acquisition under conditions of low iron availability, but the nature of the deficiency signal and its sensors are unknown. Here we report the identification of new iron regulators in rice, designated Oryza sativa Haemerythrin motif-containing Really Interesting New Gene (RING)- and Zinc-finger protein 1 (OsHRZ1) and OsHRZ2. OsHRZ1, OsHRZ2 and their Arabidopsis homologue BRUTUS bind iron and zinc, and possess ubiquitination activity. OsHRZ1 and OsHRZ2 are susceptible to degradation in roots irrespective of iron conditions. OsHRZ-knockdown plants exhibit substantial tolerance to iron deficiency, and accumulate more iron in their shoots and grains irrespective of soil iron conditions. The expression of iron deficiency-inducible genes involved in iron utilization is enhanced in OsHRZ-knockdown plants, mostly under iron-sufficient conditions. These results suggest that OsHRZ1 and OsHRZ2 are iron-binding sensors that negatively regulate iron acquisition under conditions of iron sufficiency. PMID:24253678

Nematic fluctuations in iron arsenides NaFeAs and LiFeAs probed by 75As NMR

Science.gov (United States)

Toyoda, Masayuki; Kobayashi, Yoshiaki; Itoh, Masayuki

2018-03-01

75As NMR measurements have been made on single crystals to study the nematic state in the iron arsenides NaFeAs, which undergoes a structural transition from a high-temperature (high-T ) tetragonal phase to a low-T orthorhombic phase at Ts=57 K and an antiferromagnetic transition at TN=42 K, and LiFeAs having a superconducting transition at Tc=18 K. We observe the in-plane anisotropy of the electric field gradient η even in the tetragonal phase of NaFeAs and LiFeAs, showing the local breaking of tetragonal C4 symmetry. Then, η is found to obey the Curie-Weiss (CW) law as well as in Ba (Fe1-xCox) 2As2 . The good agreement between η and the nematic susceptibility obtained by electronic Raman spectroscopy indicates that η is governed by the nematic susceptibility. From comparing η in NaFeAs and LiFeAs with η in Ba (Fe1-xCox) 2As2 , we discuss the carrier-doping dependence of the nematic susceptibility. The spin contribution to nematic susceptibility is also discussed from comparing the CW terms in η with the nuclear spin-lattice relaxation rate divided by temperature 1 /T1T . Finally, we discuss the nematic transition in the paramagnetic orthorhombic phase of NaFeAs from the in-plane anisotropy of 1 /T1T .

Investigating the effect of ascorbate on the Fe(II)-catalyzed transformation of the poorly crystalline iron mineral ferrihydrite.

Science.gov (United States)

Xiao, Wei; Jones, Adele M; Collins, Richard N; Waite, T David

2018-05-09

The inorganic core of the iron storage protein, ferritin, is recognized as being analogous to the poorly crystalline iron mineral, ferrihydrite (Fh). Fh is also abundant in soils where it is central to the redox cycling of particular soil contaminants and trace elements. In geochemical circles, it is recognized that Fh can undergo Fe(II)-catalyzed transformation to form more crystalline iron minerals, vastly altering the reactivity of the iron oxide and, in some cases, the redox poise of the system. Of relevance to both geochemical and biological systems, we investigate here if the naturally occurring reducing agent, ascorbate, can effect such an Fe(II)-catalyzed transformation of Fh at 25 °C and circumneutral pH. The transformation of ferrihydrite to possible secondary Fe(III) mineralization products was quantified using Fourier transform infrared (FTIR) spectroscopy, with supporting data obtained using X-ray absorbance spectroscopy (XAS) and X-ray diffraction (XRD). Whilst the amount of Fe(II) formed in the presence of ascorbate has resulted in Fh transformation in previous studies, no transformation of Fh to more crystalline Fe(III) (oxyhydr)oxides was observed in this study. Further experiments indicated this was due to the ability of ascorbate to inhibit the formation of goethite, lepidocrocite and magnetite. The manner in which ascorbate associated with Fh was investigated using FTIR and total organic carbon (TOC) analysis. The majority of ascorbate was found to adsorb to the Fh surface under anoxic conditions but, under oxic conditions, ascorbate was initially adsorbed then became incorporated within the Fe(III) (oxyhydr)oxide structure (i.e., co-precipitated) over time. Copyright © 2018 Elsevier B.V. All rights reserved.

The effect of Al and Cr additions on pack cementation zinc coatings

International Nuclear Information System (INIS)

Chaliampalias, D.; Papazoglou, M.; Tsipas, S.; Pavlidou, E.; Skolianos, S.; Stergioudis, G.; Vourlias, G.

2010-01-01

Zinc is widely used as a protective coating material due to its corrosion resistant properties. The structure and oxidation resistance of Al and Cr mixed zinc coatings, deposited by pack cementation process, is thoroughly examined in this work. The morphology and chemical composition of the as-deposited and oxidized samples was accomplished by electron microscopy while the phase identification was performed by XRD diffraction analysis. The experimental results showed that the addition of aluminum or chromium in the pack mixture forms only Al and Cr rich phases on the surface of the specimens without affecting significantly the phase composition of the rest zinc coatings. In the case of Zn-Al coatings, the overlying layer contains high concentrations of Al together with lower amounts of zinc and iron and in Zn-Cr coatings this layer contains Cr, Fe and Zn atoms and has much smaller thickness. The presence of these additional layers promotes significantly the oxidation resistance of the zinc pack coatings and they preserve most of their initial thickness and chemical content when exposed to an aggressive environment while their oxidation mass gain was measured at low levels during the oxidation tests.

GRAPEVINE FE-CHLOROSIS ON PODUNAVLJE VINEGROWING AREA

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Mato Drenjančević

2012-06-01

Full Text Available The characteristic of Podunavlje vinegrowing area in the far east of the Republic of Croatia is carbonate soil with loess as a parent substrate. Chlorosis is common on this soil and it is often caused by excess concentrations of calcium and magnesium and deficiency of iron and zinc. It can also be resulted by inactivation, if it is transformed so that a plant can not use it. The lack of iron in grape vine is resulted in leaf vein, first in younger leaves where the venation remains green, and then marginal necrosis and defoliation are developed. The results of the study include the data based on the field researches of Podunavlje vinegrowing subregion and exact research of fertilization field trial. Field research of Podunavlje vinegrowing subregion, vineyards of Srijem, Erdut and Baranya were conducted in July 2007. The field research consisted of locating plantations, measuring plantations chlorosis, determining their general condition and measuring total concentration of chloroplast pigments by an indirect method (chlorophyll meter on the chlorotic and nonchlorotic plants of a grapevine. The intensity of a relative chlorosis was calculated from data measured by a chlorophyll meter. Field research was located on the production area of a company Agro-Ilok ltd. in Ilok, locality Radoš, and carried out during the period 2008 and 2009. It included cultivar Welsh Riesling, grapevine stock Kober 5BB, the most important white cultivar and grapevine stock in the vinegrowing region Continental Croatia. The experiment was set up according to a split plot method at 5x3 levels. The main factor A consisted of different chemical treatments in a basic fertilization: : A1 = 0 control without fertilization; A2 = 150 kg P2O5 + 300 K2O kg ha-1 (KCl; A3 = 150 kg P2O5 + 300 K2O kg ha-1 (K2SO4; A4 = 150 kg P2O5 + 300 K2O kg ha-1 (KCl + 25 kg ha-1 Fe - FeSO4x7H2O; A5 = 150 kg P2O5 + 300 K2O kg ha-1 (K2SO4 + 25 kg ha-1 Fe - FeSO4x7H2O. Factor B had got three levels

Removal of metals from lead-zinc mine tailings using bioleaching and followed by sulfide precipitation.

Science.gov (United States)

Ye, Maoyou; Li, Guojian; Yan, Pingfang; Ren, Jie; Zheng, Li; Han, Dajian; Sun, Shuiyu; Huang, Shaosong; Zhong, Yujian

2017-10-01

Mine tailings often contain significant amounts of metals and sulfide, many traditional operations used to minerals was not as good as those currently available. This study investigated metals removal from lead-zinc mine tailings using bioleaching and followed by sulfide precipitation. Metals were dissolved from the tailings by the bacteria in a bioleaching reactor. During a 10% pulp density bioleaching experiment, approximately 0.82% Pb, 97.38% Zn, and 71.37% Fe were extracted after 50 days. With the pulp density of 10% and 20%, the dissolution of metals followed shrinking core kinetic model. Metals (Pb, Zn, and Fe) present in the pregnant bioleaching leachate. Metals were next precipitated as a sulfide phase using sodium sulfide (Na 2 S). Metal precipitations were selectively and quantitatively produced from the bioleaching leachate by adding Na 2 S. More than 99% of the zinc and 75% of the iron was precipitated using 25 g/L Na 2 S in the bioleaching leachate. The results in the study were to provide useful information for recovering or removing metals from lead-zinc mine tailings. Copyright © 2017 Elsevier Ltd. All rights reserved.

A Dilute-Limit Heat of Solution of 3d Transition Metals in Iron Studied with 57Fe Moessbauer Spectroscopy

International Nuclear Information System (INIS)

Chojcan, Jan

2004-01-01

The room-temperature 57 Fe Moessbauer spectra for binary iron-based solid solutions Fe 1-x D x with D=V, Cr, Mn and Co, were analysed in terms of binding energy E b between two D atoms in the Fe-D system. The extrapolated values of E b for x=0 were used for computation of the dilute-limit heat of solution of D metals in iron. The results were compared with those derived from calorimetric data concerning the heat of formation of the systems mentioned as well as with those resulting from the Miedema's model of alloys. The comparison shows that our Moessbauer spectroscopy findings are in a qualitative agreement with the available calorimetric data and they are at variance with corresponding Miedema's values for Fe-Mn and Fe-Co systems.

Body retention and tissue distribution of 59Fe and 54Mn in newborn rats fed iron-supplemented cow's milk

International Nuclear Information System (INIS)

Gruden, Nevenka

1980-01-01

The effect of iron-fortified cow's milk on body 59 Fe and 54 Mn retention and selective tissue distribution has been studied in newborn rats. Six-day old rats, divided into three groups were artificially fed for 7 hrs 0,45 ml of cow's milk or cow's milk enriched with either 52 or 103 μg of Fe /ml and marked with 59 Fe and 54 Mn. After 4 days there was no significant difference in whole body or carcass activity between the groups. Iron added to milk in large amounts did not influence body 59 Fe or 54 Mn retention in newborn rats, whereas it enhanced 59 Fe deposition in the liver and the intestinal wall and, to a lesser extent, 54 Mn deposition in the liver

Synthesis of LiFePO{sub 4}/polyacenes using iron oxyhydroxide as an iron source

Energy Technology Data Exchange (ETDEWEB)

Yang, Guiling; Zhang, Xianfa; Liu, Jing; He, Xingguang; Wang, Jiawei; Xie, Haiming; Wang, Rongshun [Institute of Functional Materials, Department of Chemistry, Northeast Normal University, Changchun, Jilin 130024 (China); LIB Engineering Laboratory, Materials Science and Technology Center, Changchun, Jilin 130024 (China)

2010-02-15

LiFePO{sub 4}/polyacenes (PAS) composite is synthesized by iron oxyhydroxide as a new raw material and phenol-formaldehyde resin as both reducing agent and carbon source. The mechanism of the reaction is outlined by the analysis of XRD, FTIR as well as TG/DSC. The results show that the formation of LiFePO{sub 4} is started at 300 C, and above 550 C, the product can be mainly ascribed to olivine LiFePO{sub 4}. The electrochemical properties of the synthesized composites are investigated by charge-discharge tests. It is found that the prepared sample at 750 C (S750) has a better electrochemical performance than samples prepared at other temperatures. A discharge capacity of 158 mAh g{sup -1} is delivered at 0.2 C. Under high discharge rate of 10 C, a discharge capacity of 145 mAh g{sup -1} and good capacity retention of 93% after 800 cycles are achieved. The morphology of S750 and PAS distribution in it are investigated by SEM and TEM. (author)

Atomic absorption spectrometric determination of copper, zinc, and lead in geological materials

Science.gov (United States)

Sanzolone, R.F.; Chao, T.T.

1976-01-01

An atomic absorption spectrometric method is described for the determination of copper, zinc, and lead in geological materials. The sample is digested with HF-HCl-H2O2; the final solution for analysis is in 10 % (v/v) HCl. Copper and zinc are determined directly by aspirating the solution into an air-acetylene flame. A separate aliquot of the solution is used for determination of lead; lead is extracted into TOPO-MIBK from the acidic solution in the presence of iodide and ascorbic acid. For a 0.50-g sample, the limits of determination are 10-2000 p.p.m. for Cu and Zn, and 5-5000 p.p.m. for Pb. As much as 40 % Fe or Ca. and 10 % Al, Mg, or Mn in the sample do not interfere. The proposed method can be applied to the determination of copper, zinc, and lead in a wide range of geological materials including iron- and manganese-rich, calcareous and carbonate samples. ?? 1976.

Plasma dynamic synthesis and obtaining ultrafine powders of iron oxides with high content of ε-Fe{sub 2}O{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Sivkov, Alexander [Institute of Power Engineering, National Research Tomsk Polytechnic University, Lenin av., 30, Tomsk 634050 (Russian Federation); Naiden, Evgenii [Faculty of Radiophysics, National Research Tomsk State University, Lenin av., 36, Tomsk 634050 (Russian Federation); Ivashutenko, Alexander [Institute of Power Engineering, National Research Tomsk Polytechnic University, Lenin av., 30, Tomsk 634050 (Russian Federation); Shanenkov, Ivan, E-mail: Swordi@list.ru [Institute of Power Engineering, National Research Tomsk Polytechnic University, Lenin av., 30, Tomsk 634050 (Russian Federation)

2016-05-01

The ultrafine iron oxide powders were successfully synthesized using the plasma dynamic synthesis method, based on the use of a coaxial magnetoplasma accelerator with the iron electrode system. The synthesis was implemented in the high-speed iron-containing plasma jet, flowing into the space of the sealed chamber, filled with the gaseous mixture of oxygen and argon at different ratios. The XRD investigations showed that the synthesized products were heterophase and consisted of three main phases such as magnetite Fe{sub 3}O{sub 4}, hematite α-Fe{sub 2}O{sub 3} and ε-Fe{sub 2}O{sub 3}. The SEM data confirmed the presence of three particle types: the hollow spheroids with sizes about hundreds of micrometers (magnetite), the particles with sizes up to 100 μm from the porous material of sintered submicron particles (hematite), and nanoscale particles (ε-phase). We found that at the higher oxygen concentration the content of ε-Fe{sub 2}O{sub 3} is increased up to ~50% at the same time with decreasing the Fe{sub 3}O{sub 4} phase. The magnetic properties of the products are mainly determined by magnetite characteristics and are significantly reduced with decreasing its content in the powder. In order to investigate the synthesized ε-Fe{sub 2}O{sub 3} on the ability to absorb the electromagnetic radiation in the millimeter wavelength range, we separated the product with the higher ε-phase concentration. The fraction mainly, consisting of ε-Fe{sub 2}O{sub 3}, showed the occurrence of the natural resonance at frequencies of 8.3 GHz and 130 GHz. - Highlights: • We synthesized iron oxide powder with high content of ε-Fe{sub 2}O{sub 3}. • Synthesis is implemented using iron-containing plasma jet flowing into O{sub 2} atm. • Synthesized powders are heterophase and consist of ε-Fe{sub 2}O{sub 3,} α-Fe{sub 2}O{sub 3} and Fe{sub 3}O{sub 4}. • ε-Fe{sub 2}O{sub 3} content increases up to 50% with increasing the O{sub 2} volume concentration. • We found the

Iron monoxide photodissociation

Science.gov (United States)

Chestakov, D. A.; Parker, D. H.; Baklanov, A. V.

2005-02-01

The photodissociation of Fe56O was studied by means of the velocity map imaging technique. A molecular beam of iron atoms and iron monoxide molecules was created using an electrical discharge with an iron electrode in a supersonic expansion of molecular oxygen. The ground state iron atom Fe(D45) and FeO concentrations in the molecular beam have been estimated. The dissociation energy of the FeO XΔ5 ground electronic state was found to be D00(FeO )=4.18±0.01eV. The effective absorption cross section of FeO at 252.39nm (vac), leading to the Fe(D45)+O(P3) dissociation channel, is ˜1.2×10-18cm2. A (1+1) resonantly enhanced multiphoton ionization spectrum of Fe56O in the region 39550-39580 cm-1 with rotational structure has been observed, but not assigned. Angular distributions of Fe(D45) and Fe(D35) products for the channel FeO →Fe(D4,35)+O(P3) have been measured at several points in the 210-260nm laser light wavelength region. The anisotropy parameter varies strongly with wavelength for both channels.

Iron alloy Fischer-tropsch catalysts--1. Oxidation-reduction studies of the Fe-Ni system

Energy Technology Data Exchange (ETDEWEB)

Unmuth, E.E.; Schwartz, L.H.; Butt, J.B.

1980-01-01

Catalysts containing 5% iron, nickel, or 4:1 iron-nickel on silica were hydrogen-reduced at 425/sup 0/C for 12 or 24 hr, reoxidized in air for 2 or 4 hr, reduced again in hydrogen for 12 hr, and studied at each treatment step by Moessbauer spectroscopy, X-ray diffraction, and temperature-programed desorption. The nickel was reduced directly to the metal, redispersed during the oxidation, and gave 20% smaller particles in the second reduction than in the first reduction. The ..cap alpha..-Fe/sub 2/O/sub 3/ reduced via an Fe/sub 3/O/sub 4/ intermediate and yielded approx. 70% metallic iron and the second reduction produced about the same particle size as the first reduction. The alloy catalyst reduced into a mixture of two phases, a face-centered cubic phase containing approx. 37.5% Ni, i.e., the bulk equilibrium value, and a body-centered cubic phase, and the particle sizes obtained in the first and second reductions were similar. The activation energies for the reduction were determined.

Isotope-aided studies of the bioavailability of iron and zinc from human diets consumed in Chile and Ecuador

International Nuclear Information System (INIS)

Hertrampf, E.; Pizarro, F.; Olivares, M.; Fuenmayor, G.; Yepes, R.; Soria, A.; Walter, T.

1994-01-01

Currently it is accepted that iron absorbed from infant formulas is less than 10%. However, the composition of such formulas has changed considerably and there is no recent information on the effects of these modifications. Iron bioavailability from infant formulas with different levels of iron fortification (8 and 12 mg of iron/L) and from a standard meal based on a wheat cream (''farina'' flour) was measured by a double radioisotopic technique (Eakins and Brown) in 13 adult female volunteers. Iron bioavailability in infant formulas was very high. Eighteen and 20.6 percent of the iron was absorbed in the 8 and 12 mg iron/L fortified formulas respectively (geometric means corrected to 40% of reference dose absorption). The corresponding value for iron absorption from the standard meal was 6.7%. These high and non significant differences in iron bioavailability from the two formulas and the fact that daily consumption of 750 ml of formula supplies more iron than recommended would permit a lowering of the current iron fortification level of 12 mg/L. Iron availability of the Standard Meal measured with FLAIR modifications of Miller's in vitro technique was 4.42%. The percentage of dialyzable zinc was 2.04%. Research activities for next year will be based on the validation and application of the in vitro technique in Chilean and Ecuadorian foods. (author). 26 refs, 4 tabs

Isotope-aided studies of the bioavailability of iron and zinc from human diets consumed in Chile and Ecuador