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1

Plate Rolling Modeling at Mill 5000 of OJSC ``Magnitogorsk Iron and Steel'' for Analysis and Optimization of Temperature Rates  

NASA Astrophysics Data System (ADS)

Modeling of strip deflected mode and thermal state in rolling is an integral part of the technology and perspective rolling-mill machinery such as plate mill 5000 of the OJSC "Magnitogorsk Iron and Steel". To comprehend metal behavior in the deformation zone in the rough passes during plate rolling it is essential to assess the impact of various temperature factors on variations in field of stress and strain intensities as well as temperature fields in deformation. To do such researches in consideration of various software products and adequate results one of the most effective methods nowadays is regarded as the method of finite elements. The research shows modeling of roughing rolling of a pipe steel sheet with strength category X80 according to standard API-5L. In the research of the metal deflected mode software product DEFORM 2D has been used for the isothermal and nonisothermic process. The mathematical modeling allows revealing the impact of temperature field on the metal deflected mode in the rough passes in plate rolling. Supposedly, it is deformation heating that can have more impact on the ingot temperature profile in the finishing passes in controlled rolling of the pipe steel grades. It is defined by high percent reduction, rolling speeds; more area of heat exchange surface; less thickness and lower temperature of rolling. The results can be used to develop efficient modes of plate rolling of the pipe steels.

Salganik, V.; Shmakov, A.; Pesin, A.; Pustovoytov, D.

2010-06-01

2

Seventy-five years of steel production in Magnitogorsk  

Microsoft Academic Search

The history of steel production in Magnitogorsk is outlined, from the first melt to the reconstruction of the last open-hearth\\u000a shop as an electrosmelting shop and the further enlargement of the oxygen-converter shop at OAO Magnitogorskii Metallurgicheskii\\u000a Kombinat.

V. F. Rashnikov; V. F. Sarychev; V. F. D’yachenko; A. F. Sarychev; I. M. Zakharov

2008-01-01

3

[Instability and sensitivity of the genome of healthy children in Magnitogorsk].  

PubMed

Problem of the influence of factors of the industrial city on the hereditary apparatus of its residents has not been fully resolved, because of traditionally in such studies only the pollution of environment components is taken into account. However the existence of a set of contributing socialfactors that modify the genotoxic effects ofpollution, requires the creation of a new methodology for genetic and toxicological studies. For this purpose, in Magnitogorsk, where one of Russia's largest steel plants is located, we conducted a comprehensive survey, whose tasks included the analysis of the influence of the complex of exogenous and endogenous factors on the genome of children. In this publication there are presented the results of the fifth fragment of this work - the analysis of instability and individual sensitivity of the genome of 166 children of 5-7 years, residing in two districts of Magnitogorsk: around the steel plant and on the opposite bank of Ural river, where there are no large-scale industrial enterprises. The study was conducted in the micronucleus test on peripheral blood lymphocytes cultured with cytochalasin B. For assessment of individual sensitivity of genome blood cultures were exposed to standard N-methyl-N-nitro-N-nitrosoguanidine (MNNG) mutagen. Cytogenetic analysis was performed in binucleated cells accordingly to international protocol, as well as with the use of an extended protocol including 32 indices. Average group frequency of binuclear cells with micronuclei (0.5-0.7%) were found not differ from the levels defined in children residing in Europe, and not differ between areas of the town. However the extended protocol of cytogenetic analysis discovered that the real frequency of dividing cells with lesions in blood cultures of children was 1,49-1,66%. Higher spontaneous proliferative activity of the cells and the frequency of dividing cells with injuries were found in blood cultures of children residing in settlements around the Magnitogorsk steel plant, while the individual sensitivity of the genome in these children was lower than that of their peers from the opposite bank of the Ural river A similar conclusion, but already in relation to the state of the systems for adaptation of entire body has been made from results of other fragments of the study, published earlier. PMID:24340573

Ingel', F I; Krivtsova, E K; Iurtseva, N A; Antipanova, N A; Legostaeva, T B

2013-01-01

4

Mechanism of sintering and fracture of superfluxed iron-ore sinters  

NASA Astrophysics Data System (ADS)

Mineral formation in the binders of a commercial sinter with a basicity of 1.6 at the Magnitogorsk Metallurgical Integrated Works has been found to be determined by the crystallization of two morphological forms of high-iron aluminosilicoferrite (namely, dendritic and lamellar forms) from the melt. In a sintering zone, an association of dendritic aluminosilicoferrite crystals and dicalcium silicate Ca2SiO4 forms in high-calcium melt regions separated from magnetite grains. This association leads to the fracture of the finished product as a result of the phase transformation of Ca2SiO4 from the ? into the ? modification during sinter cooling. Lamellar aluminosilicoferrites forming in high-iron sinter volumes serve as a high-strength binder for ore grains.

Malysheva, T. Ya.; Gibadulin, M. F.; Mansurova, N. R.; Lekin, V. P.

2007-06-01

5

Iron  

MedlinePLUS

Iron is a mineral that our bodies need for many functions. For example, iron is part of hemoglobin, a protein which carries ... It helps our muscles store and use oxygen. Iron is also part of many other proteins and ...

6

FUGITIVE EMISSIONS FROM INTEGRATED IRON AND STEEL PLANTS  

EPA Science Inventory

The report gives results of an engineering investigation of fugitive (non-ducted) emissions in the iron and steel industry. Operations excluded from the study are coke ovens, basic oxygen furnace (BOF) charging, and blast furnace cast houses. Fugitive emission factors for iron an...

7

Iron  

MedlinePLUS

... mealtime or when you take iron supplements.RiboflavinTaking riboflavin supplements may improve the way iron supplements work ... significant only in people with low levels of riboflavin.SoySoy protein seems to reduce the body's ability ...

8

IRON  

EPA Science Inventory

The document surveys the effects of organic and inorganic iron that are relevant to humans and their environment. The biology and chemistry of iron are complex and only partially understood. Iron participates in oxidation reduction processes that not only affect its geochemical m...

9

AP-42 ADDITIONS AND REVISIONS - INTEGRATED IRON AND STEEL INDUSTRY - STEEL MINI MILLS  

EPA Science Inventory

This project develops emission factors, etc., for the integrated iron and steel industry which are incorporated into AP-42. AP-42 is a massive collection of information concerning processes which generate air emissions and presents emission factors and control effectiveness infor...

10

MMS19 assembles iron-sulfur proteins required for DNA metabolism and genomic integrity  

PubMed Central

Instability of the nuclear genome is a hallmark of cancer and aging. MMS19 protein has been linked to maintenance of genomic integrity but the molecular basis of this connection is unknown. Here, we identify MMS19 as a member of the cytosolic iron-sulfur protein assembly (CIA) machinery. MMS19 functions as part of the CIA targeting complex that specifically interacts with and facilitates iron-sulfur cluster insertion into apoproteins involved in methionine biosynthesis, DNA replication, DNA repair and telomere maintenance. MMS19 thus serves as an adapter between early-acting CIA components and a subset of cellular iron-sulfur proteins. The function of MMS19 in maturation of crucial components of DNA metabolism may explain the sensitivity of MMS19 mutants to DNA damage and the presence of extended telomeres. PMID:22678362

Stehling, Oliver; Vashisht, Ajay A.; Mascarenhas, Judita; Jonsson, Zophonias O.; Sharma, Tanu; Netz, Daili J.A.; Pierik, Antonio J.; Wohlschlegel, James A.; Lill, Roland

2012-01-01

11

Assessing dust exposure in an integrated iron and steel manufacturing plant in South India.  

PubMed

A study to monitor and estimate respirable particulate matter (RPM), toxic trace metal concentrations in the work environment was carried out in different sections of an integrated steel manufacturing industry. The average RPM concentration observed varied according to the section blast furnace was 2.41 mg/m;{3}; energy optimization furnace, 1.87 mg/m;{3}; sintering plant, 0.98 mg/m;{3}; continuous casting machine, 1.93 mg/m;{3}. The average trace metal concentration estimated from the RPM samples like iron, manganese, lead and chromium did not exceed ACGIH prescribed levels. PMID:18413935

Ravichandran, B; Krishnamurthy, V; Ravibabu, K; Raghavan, S; Rajan, B K; Rajmohan, H R

2008-01-01

12

FISICA Integral Field Spectroscopy of the Shocked Iron Gas in the Supernova Remnant G11.2--0.3  

NASA Astrophysics Data System (ADS)

We have recently discovered strong iron line ([Fe II] (lambda)1.644 (mu)m) emission in the young supernova remnant G11.2-0.3. The iron line emission occurs at the south-eastern shell edge of G11.2-0.3, and positionally overlaps with the very strong X-ray and radio emission of the supernova remnant. The iron line emission is most likely caused by the shock acceleration of G11.2-0.3 interacting with the ambient medium. We propose to carry out JH-band integral-field spectroscopy of the two iron line clumps in G11.2-0.3 with FISICA, an image-slicing integral-field unit for FLAMINGOS, which will give us a uniquely comprehensive view of the strong shock acceleration of a SNR.

Moon, Dae-Sik; Eikenberry, Stephen S.; Koo, Bon-Chul; Raines, S. Nicholas; Gruel, Nicolas

2006-02-01

13

Superparamagnetic iron oxide nanoparticles impair endothelial integrity and inhibit nitric oxide production.  

PubMed

Superparamagnetic iron oxide nanoparticles (SPION) are widely used both clinically and experimentally for diverse in vivo applications, such as contrast enhancement in magnetic resonance imaging, hyperthermia and drug delivery. Biomedical applications require particles to have defined physical and chemical properties, and to be stable in biological media. Despite a suggested low cytotoxic action, adverse reactions of SPION in concentrations relevant for biomedical use have not yet been studied in sufficient detail. In the present work we employed Endorem®, dextran-stabilized SPION approved as an intravenous contrast agent, and compared its action to a set of other nanoparticles with potential for magnetic resonance imaging applications. SPION in concentrations relevant for in vivo applications were rapidly taken up by endothelial cells and exhibited no direct cytotoxicity. Electric cell impedance sensing measurements demonstrated that SPION, but not BaSO4/Gd nanoparticles, impaired endothelial integrity, as was confirmed by increased intercellular gap formation in endothelial monolayers. These structural changes induced the subcellular translocation and inhibition of the cytoprotective and anti-atherosclerotic enzyme endothelial NO-synthase and reduced NO production. Lipopolysaccharide-induced inflammatory NO production of macrophages was not affected by SPION. In conclusion, our data suggest that SPION might substantially alter endothelial integrity and function at therapeutically relevant doses, which are not cytotoxic. PMID:25123083

Astanina, Ksenia; Simon, Yvette; Cavelius, Christian; Petry, Sandra; Kraegeloh, Annette; Kiemer, Alexandra K

2014-11-01

14

Fracture toughness studies of gray and ductile cast irons using a J-integral approach  

E-print Network

process to determine the J values. The following empirical equations relate load line 32 TABLE 1 CHEMICAL ANALYSES OF THE VARIOUS GRAY AND NODULAR CAST IRONS STUDIED CE C Mn P S Si Ni Cr Mo Cu Mg Gray Cast Iron (4) (4) (4) (8) ' (t) (4) (5... magnification (etched) 38 Figure 16. Photomicrograph of Ni-resist D5B ductile cast iron at 84X magnification (etched) 39 Figure 17. Photomicrograph of Ni-resist DSB ductile cast iron at 200X magnification (etched) 40 Figure 18. Photomicrograph of Class...

Floyd, Donna Lynne Woodall

1981-01-01

15

Anti-plasmodial activity of aroylhydrazone and thiosemicarbazone iron chelators: effect on erythrocyte membrane integrity, parasite development and the intracellular labile iron pool.  

PubMed

Iron chelators inhibit the growth of the malaria parasite, Plasmodium falciparum, in culture and in animal and human studies. We previously reported the anti-plasmodial activity of the chelators, 2-hydroxy-1-naphthylaldehyde isonicotinoyl hydrazone (311), 2-hydroxy-1-naphthylaldehyde 4-methyl-3-thiosemicarbazone (N4mT), and 2-hydroxy-1-naphthylaldehyde 4-phenyl-3-thiosemicarbazone (N4pT). In fact, these ligands showed greater growth inhibition of chloroquine-sensitive (3D7) and chloroquine-resistant (7G8) strains of P. falciparum in culture compared to desferrioxamine (DFO). The present study examined the effects of 311, N4mT and N4pT on erythrocyte membrane integrity and asexual parasite development. While the characteristic biconcave disk shape of the erythrocytes was unaffected, the chelators caused very slight hemolysis at IC50 values that inhibited parasite growth. The chelators 311, N4mT and N4pT affected all stages of the intra-erythrocytic development cycle (IDC) of P. falciparum in culture. However, while these ligands primarily affected the ring-stage, DFO inhibited primarily trophozoite and schizont-stages. Ring, trophozoite and schizont-stages of the IDC were inhibited by significantly lower concentrations of 311, N4mT, and N4pT (IC50=4.45±1.70, 10.30±4.40, and 3.64±2.00?M, respectively) than DFO (IC50=23.43±3.40?M). Complexation of 311, N4mT and N4pT with iron reduced their anti-plasmodial activity. Estimation of the intracellular labile iron pool (LIP) in erythrocytes showed that the chelation efficacy of 311, N4mT and N4pT corresponded to their anti-plasmodial activities, suggesting that the LIP may be a potential source of non-heme iron for parasite metabolism within the erythrocyte. This study has implications for malaria chemotherapy that specifically disrupts parasite iron utilization. PMID:24028863

Walcourt, Asikiya; Kurantsin-Mills, Joseph; Kwagyan, John; Adenuga, Babafemi B; Kalinowski, Danuta S; Lovejoy, David B; Lane, Darius J R; Richardson, Des R

2013-12-01

16

Anti-Plasmodial Activity of Aroylhydrazone and Thiosemicarbazone Iron Chelators: Effect on Erythrocyte Membrane Integrity, Parasite Development and the Intracellular Labile Iron Pool  

PubMed Central

Iron chelators inhibit the growth of the malaria parasite, Plasmodium falciparum, in culture and in animal and human studies. We previously reported the anti-plasmodial activity of the chelators, 2-hydroxy-1-naphthylaldehyde isonicotinoyl hydrazone (311), 2-hydroxy-1-naphthylaldehyde 4-methyl-3-thiosemicarbazone (N4mT), and 2-hydroxy-1-naphthylaldehyde 4-phenyl-3-thiosemicarbazone (N4pT). In fact, these ligands showed greater growth inhibition of chloroquine-sensitive (3D7) and chloroquine-resistant (7G8) strains of P. falciparum in culture compared to desferrioxamine (DFO). The present study examined the effects of 311, N4mT and N4pT on erythrocyte membrane integrity and asexual parasite development. While the characteristic biconcave disk shape of the erythrocytes was unaffected, the chelators caused very slight hemolysis at IC50 values that inhibited parasite growth. The chelators 311, N4mT and N4pT affected all stages of the intra-erythrocytic development cycle (IDC) of P. falciparum in culture. However, while these ligands primarily affected the ring-stage, DFO inhibited primarily trophozoite and schizont-stages. Ring, trophozoite and schizont-stages of the IDC were inhibited by significantly lower concentrations of 311, N4mT, and N4pT (IC50 = 4.45 ± 1.70, 10.30 ± 4.40, and 3.64 ± 2.00 ?M, respectively) than DFO (IC50 = 23.43 ± 3.40 ?M). Complexation of 311, N4mT and N4pT with iron reduced their anti-plasmodial activity. Estimation of the intracellular labile iron pool (LIP) in erythrocytes showed that the chelation efficacy of 311, N4mT and N4pT corresponded to their anti-plasmodial activity, suggesting that the LIP may be a potential source of non-heme iron for parasite metabolism within the erythrocyte. This study has implications for malaria chemotherapy that specifically disrupts parasite iron utilization. PMID:24028863

Walcourt, Asikiya; Kurantsin-Mills, Joseph; Kwagyan, John; Adenuga, Babafemi B.; Kalinowski, Danuta S.; Lovejoy, David B.; Lane, Darius J. R.; Richardson, Des R.

2013-01-01

17

Iron and Iron Deficiency  

MedlinePLUS

... iron. (NIH) back to top Iron Overload and Hemochromatosis Iron overload is the accumulation of excess iron in body tissues. Hemochromatosis is the disease resulting from significant iron overload. ...

18

Probing Iron Accumulation in Sacchromyces cerevisiae Using Integrative Biophysical and Biochemical Techniques  

E-print Network

accumulates in the mutant mitochondria as inorganic phosphate Fe(III) nano-particles exhibiting superparamagnetic behaviors. Oxygen is required for iron accumulation and nanoparticle formation. The Fe(III) nano-particles can be chemically reduced to Fe...

Miao, Ren

2012-02-14

19

Monolithic integration of chalcogenide glass/iron garnet waveguides and resonators for on-chip nonreciprocal photonic devices  

NASA Astrophysics Data System (ADS)

We report monolithic integration of chalcogenide glass(ChG)/iron garnet waveguides and racetrack resonators on silicon for on-chip nonreciprocal photonic devices applications. Using a two step growth strategy, we successfully integrated phase pure Bi0.8Y2.2Fe5O12 (Bi0.8YIG), Bi1.8Y1.2Fe5O12 (Bi1.8YIG) and Ce1Y2Fe5O12 (CeYIG) polycrystalline thin films on silicon with low fabrication thermal budgets. Strip-loaded ChG/Iron garnet waveguides and racetrack resonators were fabricated by thermal evaporation and lift off. The waveguide loss was systematically characterized by cutback and paperclip methods. For the first time, the optical transmission loss of polycrystalline Bi or Ce doped garnets were evaluated at communication wavelengths in waveguides. Polycrystalline CeYIG films show a saturation Faraday rotation of -830deg/cm and transmission loss of {40dB/cm at 1550nm, which is promising for on-chip nonreciprocal photonic device applications. Such waveguide structures were successfully incorporated in GeS2/Bi0.8YIG racetrack resonators which show well defined resonance spectrum at near infrared wavelength. The nonreciprocal phase shift (NRPS) and device figure of merit of the ChG/Garnet waveguides were simulated by numerical methods. Possible improvements and applications of such devices for integrated optical isolator applications are analyzed and discussed.

Bi, Lei; Hu, Juejun; Dionne, Gerald F.; Kimerling, Lionel; Ross, C. A.

2011-01-01

20

Novel insights into iron metabolism by integrating deletome and transcriptome analysis in an iron deficiency model of the yeast Saccharomyces cerevisiae  

Microsoft Academic Search

BACKGROUND: Iron-deficiency anemia is the most prevalent form of anemia world-wide. The yeast Saccharomyces cerevisiae has been used as a model of cellular iron deficiency, in part because many of its cellular pathways are conserved. To better understand how cells respond to changes in iron availability, we profiled the yeast genome with a parallel analysis of homozygous deletion mutants to

William J Jo; Jeung Hyoun Kim; Eric Oh; Daniel Jaramillo; Patricia Holman; Alex V Loguinov; Adam P Arkin; Corey Nislow; Guri Giaever; Chris D Vulpe

2009-01-01

21

Machinability of Austempered Ductile Iron (ADI) Produced by Integrated Green Technology of Continuous Casting-Heat Treatment Processes  

SciTech Connect

This study presents the novel processing technique known as continuous casting-heat treatment processes to produce Austempered Ductile Iron (ADI) which is a new class of ductile iron. ADI is characterized by improved mechanical properties but has low machinability as compared to other cast irons and steel of similar strength. The novel technique is developed by the integration of casting (in die casting) and heat treatment processes in foundry to save cost energy and time. Specimens just after casting were austenitized at 930 deg. C for 90 min and then austempered in fluidized bed at 380 deg. C for 90 and 120 min. Hence, the effect of austempering time on the morphology of retained austenite and mechanical properties of the material were examined and compared with conventionally produced ADI. Drilling tests were then carried out to evaluate the machinability of ADI in terms of cutting forces, chip micro-hardness, chip morphology and surface roughness. The mechanical properties of ADI austempered for 120 min have found to be better as compare to the ADI austempered for 90 min.

Meena, A.; El Mansori, M.; Ghidossi, P. [Arts et Metiers ParisTech, LMPF-EA 4106, Rue Saint Dominique, BP 508, 51006, Chalons-en-Champagne, Cedex (France)

2011-01-17

22

Corrosion of iron and low alloyed steel within a water saturated brick of clay under anaerobic deep geological disposal conditions: An integrated experiment  

Microsoft Academic Search

The aim of this study was to determine the corrosion behaviour of iron and low alloyed steels under simulated geological disposal conditions, related to long-term disposal of nuclear wastes in the site of Bure (Meuse-Haute Marne, Champagne, France). The dedicated experiment was a fully integrated set-up: three different bars of material (iron, steel or nickel) have been introduced inside a

F. A. Martin; C. Bataillon; M. L. Schlegel

2008-01-01

23

FIELD DEMONSTRATION OF EMERGING PIPE WALL INTEGRITY ASSESSMENT TECHNOLOGIES FOR LARGE CAST IRON WATER MAINS  

EPA Science Inventory

The U.S. Environmental Protection Agency sponsored a large-scale field demonstration of innovative leak detection/location and condition assessment technologies on a 76-year old, 2,500-ft long, cement-lined, 24-in. cast iron water main in Louisville, KY from July through Septembe...

24

Field Demonstration of Emerging Pipe Wall Integrity Assessment Technologies for Large Cast Iron Water Mains - Paper  

EPA Science Inventory

The U.S. Environmental Protection Agency (EPA) sponsored a large-scale field demonstration of innovative leak detection/location and condition assessment technologies on a 76-year old, 2,000-ft long, cement-lined, 24-in. cast-iron water main in Louisville, KY from July through Se...

25

Anisotropy of the Hopping Integrals of Calcium Doped Yttrium Iron Garnet  

Microsoft Academic Search

\\u000a The main objective of this paper is to indicate a possible origin of strong magnetic anisotropy of the electric resistance\\u000a in calcium-doped yttrium-iron garnets (Ca : YIG). Recent measurements of the electric resistance of the as-grown Ca : YIG\\u000a samples show strong anisotropy connected with differ- ent orientations of the applied magnetic field with respect to the electric\\u000a current. The

A. Lehmann-Szweykowska; R. J. Wojciechowski; J. Barna?; P. E. Wigen

26

Effect of temperature on fast hydrogen diffusion in iron: A path-integral quantum dynamics approach  

Microsoft Academic Search

Here we explicitly present the diffusion coefficients (D) and activation energies (Ea) of interstitial H in alpha-Fe over a temperature range of 100 to 1000 K. These values were predicted by applying path-integral molecular dynamics modeling based on first principles. The obtained D and Ea values exhibit clear non-Arrhenius temperature dependence and a transition from quantum to classical behavior at

Hajime Kimizuka; Hideki Mori; Shigenobu Ogata

2011-01-01

27

The GEF1 gene of Saccharomyces cerevisiae encodes an integral membrane protein; mutations in which have effects on respiration and iron-limited growth.  

PubMed

We have isolated a new class of respiration-defective, i.e petite, mutants of the yeast Saccharomyces cerevisiae. Mutations in the GEF1 gene cause cells to grow slowly on rich media containing carbon sources utilized by respiration. This phenotype is suppressed by adding high concentrations of iron to the growth medium. Gef1- mutants also fail to grow on a fermentable carbon source, glucose, when iron is reduced to low concentrations in the medium, suggesting that the GEF1 gene is required for efficient metabolism of iron during growth on fermentable as well as respired carbon sources. However, activity of the iron uptake system appears to be unaffected in gef1- mutants. Fe(II) transporter activity and regulation is normal in gef1- mutants. Fe(III) reductase induction during iron-limited growth is disrupted, but this appears to be a secondary effect of growth rate alterations. The wild-type GEF1 gene was cloned and sequenced; it encodes a protein of 779 amino acids, 13 possible transmembrane domains, and significant similarity to chloride channel proteins from fish and mammals, suggesting that GEF1 encodes an integral membrane protein. A gef1- deletion mutation generated in vitro and introduced into wild-type haploid strains by gene transplacement was not lethal. Oxygen consumption by intact gef1- cells and by mitochondrial fractions isolated from gef1- mutants was reduced 25-50% relative to wild type, indicating that mitochondrial function is defective in these mutants. We suggest that GEF1 encodes a transport protein that is involved in intracellular iron metabolism. PMID:7505388

Greene, J R; Brown, N H; DiDomenico, B J; Kaplan, J; Eide, D J

1993-12-01

28

Production and blast-furnace smelting of boron-alloyed iron-ore pellets  

SciTech Connect

Industrial test data are presented regarding the production (at Sokolovsk-Sarbaisk mining and enrichment enterprise) and blast-furnace smelting (at Magnitogorsk metallurgical works) of boron-alloyed iron-ore pellets (500000 t). It is shown that, thanks to the presence of boron, the compressive strength of the roasted pellets is increased by 18.5%, while the strength in reduction is doubled; the limestone consumption is reduced by 11%, the bentonite consumption is halved, and the dust content of the gases in the last section of the roasting machines is reduced by 20%. In blast-furnace smelting, the yield of low-sulfur (<0.02%) hot metal is increased from 65-70 to 85.1% and the furnace productivity from 2.17-2.20 to 2.27 t/(m{sup 3} day); coke consumption is reduced by 3-8 kg/t of hot metal. The plasticity and stamping properties of 08IO auto-industry steel are improved by microadditions of boron.

A.A. Akberdin; A.S. Kim [Abishev Chemicometallurgical Institute, Abishev (Kazakhstan)

2008-08-15

29

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

PubMed Central

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. PMID:24600464

Borrill, Philippa; Connorton, James M.; Balk, Janneke; Miller, Anthony J.; Sanders, Dale; Uauy, Cristobal

2014-01-01

30

Magneto-optical properties of cerium substituted yttrium iron garnet films with reduced thermal budget for monolithic photonic integrated circuits.  

PubMed

Thin films of polycrystalline cerium substituted yttrium iron garnet (CeYIG) were grown on an yttrium iron garnet (YIG) seed layer on Si and Si-on-insulator substrates by pulsed laser deposition, and their optical and magneto-optical properties in the near-IR region were measured. A YIG seed layer of ~30 nm thick processed by rapid thermal anneal at 800°C provided a virtual substrate to promote crystallization of the CeYIG. The effect of the thermal budget of the YIG/CeYIG growth process on the film structure, magnetic and magnetooptical properties was determined. PMID:23263087

Goto, Taichi; Onba?l?, Mehmet C; Ross, C A

2012-12-17

31

Investigation of the Biophysical and Cell Biological Properties of Ferroportin, a Multi-Pass Integral Membrane Protein Iron Exporter  

PubMed Central

Ferroportin is a multi-pass membrane protein that serves as an iron exporter in many vertebrate cell types. Ferroportin-mediated iron export is controlled by the hormone hepcidin, which binds ferroportin, causing its internalization and degradation. Mutations in ferroportin cause a form of the iron overload disease hereditary hemochromatosis. Relatively little is known about ferroportin’s properties or the mechanism by which mutations cause disease. Here we expressed and purified human ferroportin to characterize its biochemical/biophysical properties in solution and conducted cell biological studies in mammalian cells. We show that purified, detergent-solubilized ferroportin was a well-folded monomer that bound hepcidin. In cell membranes, the N- and C-termini were both cytosolic, implying an even number of transmembrane regions, and ferroportin was mainly localized to the plasma membrane. Hepcidin addition resulted in a redistribution of ferroportin to intracellular compartments that labeled with early endosomal and lysosomal, but not Golgi, markers and that trafficked along microtubules. An analysis of 16 disease-related ferroportin mutants revealed that all formed well-folded monomers that localized to the plasma membrane, but some were resistant to hepcidin-induced internalization. The characterizations reported here form a basis upon which models for ferroportin’s role in regulating iron homeostasis in health and disease can be interpreted. PMID:19150361

Rice, Adrian E.; Mendez, Michael J.; Hokanson, Craig A.; Rees, Douglas C.; Björkman, Pamela J.

2009-01-01

32

Regulation of cellular iron metabolism  

PubMed Central

Iron is an essential but potentially hazardous biometal. Mammalian cells require sufficient amounts of iron to satisfy metabolic needs or to accomplish specialized functions. Iron is delivered to tissues by circulating transferrin, a transporter that captures iron released into the plasma mainly from intestinal enterocytes or reticuloendothelial macrophages. The binding of iron-laden transferrin to the cell-surface transferrin receptor 1 results in endocytosis and uptake of the metal cargo. Internalized iron is transported to mitochondria for the synthesis of haem or iron–sulfur clusters, which are integral parts of several metalloproteins, and excess iron is stored and detoxified in cytosolic ferritin. Iron metabolism is controlled at different levels and by diverse mechanisms. The present review summarizes basic concepts of iron transport, use and storage and focuses on the IRE (iron-responsive element)/IRP (iron-regulatory protein) system, a well known post-transcriptional regulatory circuit that not only maintains iron homoeostasis in various cell types, but also contributes to systemic iron balance. PMID:21348856

Wang, Jian; Pantopoulos, Kostas

2011-01-01

33

Vacuum annealed cerium-substituted yttrium iron garnet films on non-garnet substrates for integrated optical circuits  

SciTech Connect

Polycrystalline cerium-substituted yttrium iron garnet (CeYIG) showing large Faraday rotation (FR) in the near-IR region was grown on non-garnet (synthetic fused silica, Si, and Si-on-insulator) substrates by sputtering followed by thermal annealing in vacuum. The FR of the films is comparable to the single crystal value. Structural characterization, magnetic properties, refractive index, extinction coefficient, surface topography, and FR vs. wavelength were measured and the magnetooptical figure of merit was compared with that of CeYIG films on garnet substrates.

Goto, Taichi; Ross, C. A. [Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139 (United States); Eto, Yu; Kobayashi, Keiichi; Haga, Yoji; Inoue, Mitsuteru [Toyohashi University of Technology, Hibarigaoka, Tempaku, Toyohashi, Aichi 441-8580 (Japan)

2013-05-07

34

The MAP kinase MpkA controls cell wall integrity, oxidative stress response, gliotoxin production and iron adaptation in Aspergillus fumigatus  

PubMed Central

The saprophytic fungus Aspergillus fumigatus is the most important air-borne fungal pathogen. The cell wall of A. fumigatus has been studied intensively as a potential target for development of effective antifungal agents. A major role in maintaining cell wall integrity is played by the mitogen-activated protein kinase (MAPK) MpkA. To gain a comprehensive insight into this central signal transduction pathway, we performed a transcriptome analysis of the ?mpkA mutant under standard and cell wall stress conditions. Besides genes involved in cell wall remodelling, protection against ROS and secondary metabolism such as gliotoxin, pyomelanin and pseurotin A, also genes involved in siderophore biosynthesis were regulated by MpkA. Consistently, northern and western blot analyses indicated that iron starvation triggers phosphorylation and thus activation of MpkA. Furthermore, localization studies indicated that MpkA accumulates in the nucleus under iron depletion. Hence, we report the first connection between a MAPK pathway and siderophore biosynthesis. The measurement of amino acid pools and of the pools of polyamines indicated that arginine was continuously converted into ornithine to fuel the siderophore pool in the ?mpkA mutant strain. Based on our data, we propose that MpkA fine-tunes the balance between stress response and energy consuming cellular processes. PMID:21883519

Jain, Radhika; Valiante, Vito; Remme, Nicole; Docimo, Teresa; Heinekamp, Thorsten; Hertweck, Christian; Gershenzon, Jonathan; Haas, Hubertus; Brakhage, Axel A

2011-01-01

35

Application of direct-injection detector integrated with the multi-pumping flow system to photometric stop-flow determination of total iron.  

PubMed

A novel direct-injection detector (DID) integrated with multi-pumping flow system (MPFS) for the photometric determination of iron is proposed. Paired emitter-detector diodes have been used as a photometric detection system. The sample and reagent were injected using appropriate solenoid pulse micro-pumps directly into the detection chamber where effective mixing occured. The use of proposed stop-flow detector considerably simplified the analytical procedure. The potassium thiocyanate has been chosen as a chromogenic reagent for photometric Fe(III) detection. The total volume of reagent and sample/standard solutions involved in the detection process was adjusted to the volume of the reaction-detection chamber. Calibration graph was found to be linear in the range up to 10mgL(-1). The detection limit (3s(b)/S) was 0.15mgL(-1). The repeatability (R.S.D.), calculated from 10 analyses of sample containing 5mgL(-1) Fe(III), was 1.5% and the sample throughput 180 determinations per hour. The consumption of sample and reagent was 20?L each with the waste generation at the level of 0.24mL. The applicability of the proposed method to the determination of total iron in groundwater samples has been proved. The analytical parameters are compared to those obtained exploiting the MPFS system with typical configuration containing a confluence point and reaction coil. PMID:22817930

Koronkiewicz, Stanislawa; Kalinowski, Slawomir

2012-07-15

36

Integrated Self-Assembly of the Mms6 Magnetosome Protein to Form an Iron-Responsive Structure  

PubMed Central

A common feature of biomineralization proteins is their self-assembly to produce a surface consistent in size with the inorganic crystals that they produce. Mms6, a small protein of 60 amino acids from Magnetospirillum magneticum strain AMB-1 that promotes the in vitro growth of superparamagnetic magnetite nanocrystals, assembles in aqueous solution to form spherical micelles that could be visualized by TEM and AFM. The results reported here are consistent with the view that the N and C-terminal domains interact with each other within one polypeptide chain and across protein units in the assembly. From studies to determine the amino acid residues important for self-assembly, we identified the unique GL repeat in the N-terminal domain with additional contributions from amino acids in other positions, throughout the molecule. Analysis by CD spectroscopy identified a structural change in the iron-binding C-terminal domain in the presence of Fe3+. A change in the intrinsic fluorescence of tryptophan in the N-terminal domain showed that this structural change is transmitted through the protein. Thus, self-assembly of Mms6 involves an interlaced structure of intra- and inter-molecular interactions that results in a coordinated structural change in the protein assembly with iron binding. PMID:23857056

Feng, Shuren; Wang, Lijun; Palo, Pierre; Liu, Xunpei; Mallapragada, Surya K.; Nilsen-Hamilton, Marit

2013-01-01

37

The Integrated Role of Desferrioxamine and Phenserine Targeted to an Iron-Responsive Element in the APP-mRNA 5'-Untranslated Region  

Microsoft Academic Search

The Alzheimer's amyloid precursor protein (APP) is the metallo- protein that is cleaved to generate the pathogenic Apeptide. We showed that iron closely regulated the expression of APP by 5'-untranslated region (5'- UTR) sequences in APP mRNA. Iron modulated APP holoprotein expression by a pathway similar to iron control of the translation of the ferritin-L and -H mRNAs by iron-responsive

AMANDA VENTI; TONY GIORDANO; PAUL EDER; ASHLEY I. BUSH; DEBOMOY K. LAHIRI; NIGEL H. GREIG; JACK T. ROGERSa

2004-01-01

38

Eat Iron?!!  

NSDL National Science Digital Library

To gain an understanding of mixtures and the concept of separation of mixtures, students use strong magnets to find the element of iron in iron-fortified breakfast cereal flakes. Through this activity, they see how the iron component of this heterogeneous mixture (cereal) retains its properties and can thus be separated by physical means.

NSF GK-12 and Research Experience for Teachers (RET) Programs,

39

Human CIA2A (FAM96A) and CIA2B (FAM96B) integrate maturation of different subsets of cytosolic-nuclear iron-sulfur proteins and iron homeostasis  

PubMed Central

SUMMARY Numerous cytosolic and nuclear proteins involved in metabolism, DNA maintenance, protein translation, or iron homeostasis depend on iron-sulfur (Fe/S) cofactors, yet their assembly is poorly defined. Here, we identify and characterize human CIA2A (FAM96A), CIA2B (FAM96B), and CIA1 (CIAO1) as components of the cytosolic Fe/S protein assembly (CIA) machinery. CIA1 associates with either CIA2A or CIA2B and the CIA targeting factor MMS19. The CIA2B-CIA1-MMS19 complex binds to and facilitates assembly of most cytosolic-nuclear Fe/S proteins. In contrast, CIA2A specifically matures iron regulatory protein (IRP) 1 which is critical for cellular iron homeostasis. Surprisingly, a second layer of iron regulation involves the stabilization of IRP2 by CIA2A binding or upon depletion of CIA2B or MMS19, even though IRP2 lacks a Fe/S cluster. In summary, CIA2B-CIA1-MMS19 and CIA2A-CIA1 assist different branches of Fe/S protein assembly, and intimately link this process to cellular iron regulation via IRP1 Fe/S cluster maturation and IRP2 stabilization. PMID:23891004

Stehling, Oliver; Mascarenhas, Judita; Vashisht, Ajay A.; Sheftel, Alex D.; Niggemeyer, Brigitte; Rösser, Ralf; Pierik, Antonio J.; Wohlschlegel, James A.; Lill, Roland

2013-01-01

40

Microbial iron cycling in acidic geothermal springs of yellowstone national park: integrating molecular surveys, geochemical processes, and isolation of novel fe-active microorganisms.  

PubMed

Geochemical, molecular, and physiological analyses of microbial isolates were combined to study the geomicrobiology of acidic iron oxide mats in Yellowstone National Park. Nineteen sampling locations from 11 geothermal springs were studied ranging in temperature from 53 to 88°C and pH 2.4 to 3.6. All iron oxide mats exhibited high diversity of crenarchaeal sequences from the Sulfolobales, Thermoproteales, and Desulfurococcales. The predominant Sulfolobales sequences were highly similar to Metallosphaera yellowstonensis str. MK1, previously isolated from one of these sites. Other groups of archaea were consistently associated with different types of iron oxide mats, including undescribed members of the phyla Thaumarchaeota and Euryarchaeota. Bacterial sequences were dominated by relatives of Hydrogenobaculum spp. above 65-70°C, but increased in diversity below 60°C. Cultivation of relevant iron-oxidizing and iron-reducing microbial isolates included Sulfolobus str. MK3, Sulfobacillus str. MK2, Acidicaldus str. MK6, and a new candidate genus in the Sulfolobales referred to as Sulfolobales str. MK5. Strains MK3 and MK5 are capable of oxidizing ferrous iron autotrophically, while strain MK2 oxidizes iron mixotrophically. Similar rates of iron oxidation were measured for M. yellowstonensis str. MK1 and Sulfolobales str. MK5. Biomineralized phases of ferric iron varied among cultures and field sites, and included ferric oxyhydroxides, K-jarosite, goethite, hematite, and scorodite depending on geochemical conditions. Strains MK5 and MK6 are capable of reducing ferric iron under anaerobic conditions with complex carbon sources. The combination of geochemical and molecular data as well as physiological observations of isolates suggests that the community structure of acidic Fe mats is linked with Fe cycling across temperatures ranging from 53 to 88°C. PMID:22470372

Kozubal, Mark A; Macur, Richard E; Jay, Zackary J; Beam, Jacob P; Malfatti, Stephanie A; Tringe, Susannah G; Kocar, Benjamin D; Borch, Thomas; Inskeep, William P

2012-01-01

41

Integration  

ERIC Educational Resources Information Center

Integrated learning is an exciting adventure for both teachers and students. It is not uncommon to observe the integration of academic subjects such as math, science, and language arts. However, educators need to recognize that movement experiences in physical education also can be linked to academic curricula and, may even lead the…

Kalyn, Brenda

2006-01-01

42

Bacterial iron homeostasis  

Microsoft Academic Search

Iron is essential to virtually all organisms, but poses problems of toxicity and poor solubility. Bacteria have evolved various mechanisms to counter the problems imposed by their iron dependence, allowing them to achieve effective iron homeostasis under a range of iron regimes. Highly efficient iron acquisition systems are used to scavenge iron from the environment under iron-restricted conditions. In many

Simon C Andrews; Andrea K Robinson; Francisco Rodr??guez-Quiñones

2003-01-01

43

Integration  

NSDL National Science Digital Library

In this video, we become familiar with integrals, both by understanding them as sums of areas under plots of functions, and by understanding them as anti-derivatives. We present the u-substitution rule, which is the analog of the chain rule for differentiating composite functions.

2013-06-21

44

An integrative computational model for large-scale identification of metalloproteins in microbial genomes: a focus on iron-sulfur cluster proteins.  

PubMed

Metalloproteins represent a ubiquitous group of molecules which are crucial to the survival of all living organisms. While several metal-binding motifs have been defined, it remains challenging to confidently identify metalloproteins from primary protein sequences using computational approaches alone. Here, we describe a comprehensive strategy based on a machine learning approach to design and assess a penalized generalized linear model. We used this strategy to detect members of the iron-sulfur cluster protein family. A new category of descriptors, whose profile is based on profile hidden Markov models, encoding structural information was combined with public descriptors into a linear model. The model was trained and tested on distinct datasets composed of well-characterized iron-sulfur protein sequences, and the resulting model provided higher sensitivity compared to a motif-based approach, while maintaining a good level of specificity. Analysis of this linear model allows us to detect and quantify the contribution of each descriptor, providing us with a better understanding of this complex protein family along with valuable indications for further experimental characterization. Two newly-identified proteins, YhcC and YdiJ, were functionally validated as genuine iron-sulfur proteins, confirming the prediction. The computational model was then applied to over 550 prokaryotic genomes to screen for iron-sulfur proteomes; the results are publicly available at: . This study represents a proof-of-concept for the application of a penalized linear model to identify metalloprotein superfamilies on a large-scale. The application employed here, screening for iron-sulfur proteomes, provides new candidates for further biochemical and structural analysis as well as new resources for an extensive exploration of iron-sulfuromes in the microbial world. PMID:25117543

Estellon, Johan; Ollagnier de Choudens, Sandrine; Smadja, Myriam; Fontecave, Marc; Vandenbrouck, Yves

2014-10-01

45

Integration of bulk-quality thin film magneto-optical cerium-doped yttrium iron garnet on silicon nitride photonic substrates.  

PubMed

Cerium substituted yttrium iron garnet (Ce:YIG) films were grown on yttrium iron garnet (YIG) seed layers on silicon nitride films using pulsed laser deposition. Optimal process conditions for forming garnet films on silicon nitride are presented. Bulk or near-bulk magnetic and magneto-optical properties were observed for 160 nm thick Ce:YIG films grown at 640 °C on rapid thermal annealed 40 nm thick YIG grown at 640 °C and 2 Hz pulse rate. The effect of growth temperature and deposition rate on structural, magnetic and magneto-optical properties has been investigated. PMID:25401550

Onbasli, Mehmet C; Goto, Taichi; Sun, Xueyin; Huynh, Nathalie; Ross, C A

2014-10-20

46

Iron and alloys of iron. [lunar resources  

NASA Technical Reports Server (NTRS)

All lunar soil contains iron in the metallic form, mostly as an iron-nickel alloy in concentrations of a few tenths of 1 percent. Some of this free iron can be easily separated by magnetic means. It is estimated that the magnetic separation of 100,000 tons of lunar soil would yield 150-200 tons of iron. Agglutinates contain metallic iron which could be extracted by melting and made into powder metallurgy products. The characteristics and potential uses of the pure-iron and iron-alloy lunar products are discussed. Processes for working iron that might be used in a nonterrestrial facility are also addressed.

Sastri, Sankar

1992-01-01

47

The GEF1 gene of Saccharomyces cerevisiae encodes an integral membrane protein; mutations in which have effects on respiration and iron-limited growth  

Microsoft Academic Search

We have isolated a new class of respiration-defective, i.e petite, mutants of the yeast Saccharomyces cerevisiae. Mutations in the GEF1 gene cause cells to grow slowly on rich media containing carbon sources utilized by respiration. This phenotype is suppressed by adding high concentrations of iron to the growth medium. Gef1- mutants also fail to grow on a fermentable carbon source,

Jonathan R. Greene; Nathaniel H. Brown; Beth J. DiDomenico; Jerry Kaplan; David J. Eide

1993-01-01

48

An encapsulation of iron homeostasis and virulence in Cryptococcus neoformans  

PubMed Central

Vertebrate hosts actively sequester iron, and fungal and other pathogens must therefore adapt to a severe limitation in iron availability to cause disease. Recent studies reveal that the pathogenic fungus Cryptococcus neoformans overcomes iron limitation by multiple mechanisms that target transferrin and heme. The regulation of iron uptake is mediated by an interconnected set of transcription factors that include the master iron regulator Cir1 and the pH-responsive factor Rim 101. These factors integrate iron homeostasis with a myriad of other functions including pH sensing, nutrient and stress signaling pathways, virulence factor elaboration and cell wall biogenesis. PMID:23810126

Kronstad, James W.; Hu, Guanggan; Jung, Won Hee

2013-01-01

49

Pharmacology of Iron Transport  

PubMed Central

Elucidating the molecular basis for the regulation of iron uptake, storage, and distribution is necessary to understand iron homeostasis. Pharmacological tools are emerging to identify and distinguish among different iron transport pathways. Stimulatory or inhibitory small molecules with effects on iron uptake can help characterize the mechanistic elements of iron transport and the roles of the transporters involved in these processes. In particular, iron chelators can serve as potential pharmacological tools to alleviate diseases of iron overload. This review focuses on the pharmacology of iron transport, introducing iron transport membrane proteins and known inhibitors. PMID:23020294

Byrne, Shaina L.; Krishnamurthy, Divya; Wessling-Resnick, Marianne

2013-01-01

50

Snapshot of iron response in Shewanella oneidensis by gene network reconstruction  

Microsoft Academic Search

BACKGROUND: Iron homeostasis of Shewanella oneidensis, a ?-proteobacterium possessing high iron content, is regulated by a global transcription factor Fur. However, knowledge is incomplete about other biological pathways that respond to changes in iron concentration, as well as details of the responses. In this work, we integrate physiological, transcriptomics and genetic approaches to delineate the iron response of S. oneidensis.

Yunfeng Yang; Daniel P Harris; Feng Luo; Wenlu Xiong; Marcin Joachimiak; Liyou Wu; Paramvir Dehal; Janet Jacobsen; Zamin Yang; Anthony V Palumbo; Adam P Arkin; Jizhong Zhou

2009-01-01

51

Development of an integrated in-situ remediation technology. Draft topical report for Task {number_sign}3.3 entitled, ``Iron dechlorination studies`` (September 26, 1994--August 31, 1997)  

SciTech Connect

Contamination in low-permeability soils poses a significant technical challenge to in-situ remediation efforts. Poor accessibility to the contaminants and difficulty in delivery of treatment reagents have rendered existing in-situ treatments such as bioremediation, vapor extraction, and pump and treat rather ineffective when applied to low permeability soils present at many contaminated sites. The technology is an integrated in-situ treatment in which established geotechnical methods are used to install degradation zones directly in the contaminated soil and electro-osmosis is utilized to move the contaminants back and forth through those zones until the treatment is completed. The present Topical Report for Task {number_sign}3.3 summarizes the iron dechlorination research conducted by Monsanto Company.

Orth, R.; Dauda, T.; McKenzie, D.E.

1997-11-01

52

Iron metabolism and toxicity  

SciTech Connect

Iron is an essential nutrient with limited bioavailability. When present in excess, iron poses a threat to cells and tissues, and therefore iron homeostasis has to be tightly controlled. Iron's toxicity is largely based on its ability to catalyze the generation of radicals, which attack and damage cellular macromolecules and promote cell death and tissue injury. This is lucidly illustrated in diseases of iron overload, such as hereditary hemochromatosis or transfusional siderosis, where excessive iron accumulation results in tissue damage and organ failure. Pathological iron accumulation in the liver has also been linked to the development of hepatocellular cancer. Here we provide a background on the biology and toxicity of iron and the basic concepts of iron homeostasis at the cellular and systemic level. In addition, we provide an overview of the various disorders of iron overload, which are directly linked to iron's toxicity. Finally, we discuss the potential role of iron in malignant transformation and cancer.

Papanikolaou, G. [First Department of Internal Medicine, National and Kapodistrian University of Athens, School of Medicine, Laikon General Hospital, Athens 11527 (Greece); Pantopoulos, K. [Lady Davis Institute for Medical Research, Sir Mortimer B. Davis Jewish General Hospital, Montreal, Quebec, H3T 1E2 (Canada) and Department of Medicine, McGill University (Canada)]. E-mail: kostas.pantopoulos@mcgill.ca

2005-01-15

53

Iron deficiency anemia  

MedlinePLUS

Anemia - iron deficiency ... Iron deficiency anemia is the most common form of anemia. Red blood cells bring oxygen to the ... such as your spleen, remove old blood cells. Iron is a key part of red blood cells. ...

54

Iron Sucrose Injection  

MedlinePLUS

... any other iron injection such as ferumoxytol (Feraheme), iron dextran (Dexferrum, Infed, Proferdex), or sodium ferric gluconate (Ferrlecit); any other medications; or any of the ingredients in iron sucrose injection. Ask your pharmacist for a list ...

55

Saugus Iron Works Forge  

USGS Multimedia Gallery

The Saugus Iron Works forge, which used a large hammer to compress the iron. Forging strenghened the iron, which, right out of the blast furnace, was brittle. The Saugus River, which powered the forge, can be seen in the background....

56

Iron and vegetarian diets.  

PubMed

Vegetarians who eat a varied and well balanced diet are not at any greater risk of iron deficiency anaemia than non-vegetarians. A diet rich in wholegrains, legumes, nuts, seeds, dried fruits, iron-fortified cereals and green leafy vegetables provides an adequate iron intake. Vitamin C and other organic acids enhance non-haem iron absorption, a process that is carefully regulated by the gut. People with low iron stores or higher physiological need for iron will tend to absorb more iron and excrete less. Research to date on iron absorption has not been designed to accurately measure absorption rates in typical Western vegetarians with low ferritin levels. PMID:25369923

Saunders, Angela V; Craig, Winston J; Baines, Surinder K; Posen, Jennifer S

2013-08-19

57

The liver: conductor of systemic iron balance  

PubMed Central

Iron is a micronutrient essential for almost all organisms: bacteria, plants, and animals. It is a metal that exists in multiple redox states, including the divalent ferrous (Fe2+) and the trivalent ferric (Fe3+) species. The multiple oxidation states of iron make it excellent for electron transfer, allowing iron to be selected during evolution as a cofactor for many proteins involved in central cellular processes including oxygen transport, mitochondrial respiration, and DNA synthesis. However, the redox cycling of ferrous and ferric iron in the presence of H2O2, which is physiologically present in the cells, also leads to the production of free radicals (Fenton reaction) that can attack and damage lipids, proteins, DNA, and other cellular components. To meet the physiological needs of the body, but to prevent cellular damage by iron, the amount of iron in the body must be tightly regulated. Here we review how the liver is the central conductor of systemic iron balance and show that this central role is related to the secretion of a peptide hormone hepcidin by hepatocytes. We then review how the liver receives and integrates the many signals that report the body’s iron needs to orchestrate hepcidin production and maintain systemic iron homeostasis. PMID:24200681

Meynard, Delphine; Babitt, Jodie L.

2014-01-01

58

Iron fluorophosphates.  

PubMed

18 new iron fluorophosphates and a chlorofluorophosphate have been synthesised hydrothermally in a fluoride-rich medium, using FeF2, FeF3, Fe, HPF6. HCl, monovalent metal fluorides as reactants and amines as templating agents. Products have been fully structurally characterised using single crystal X-ray diffraction, and the stability of some compounds investigated using thermogravimetric analysis. Reaction in fluoride-rich conditions produce ribbon-like, layer and framework structures containing new and unusual structural motifs based on the linking of Fe(O,F)6, PO3F, and PO2(OH,F)2 polyhedra. Structures exhibiting inter-layer spaces and channels are frequently lined by terminal fluoride anions of the PO3F, PO2(OH,F)2 and Fe(O,F)6 polyhedra. PMID:23770666

Keates, Adam C; Armstrong, Jennifer A; Weller, Mark T

2013-08-14

59

Iron speciation and dynamics during SERIES, a mesoscale iron enrichment experiment in the NE Pacific  

NASA Astrophysics Data System (ADS)

During the Sub-arctic Ecosystem Response to Iron Enrichment Study (SERIES), the addition of ferrous iron to high-nitrate low-chlorophyll (HNLC) waters near Ocean Station PAPA (OSP: 50°N, 145°W) produced a phytoplankton bloom and CO 2 drawdown, as evidenced by decreasing CO 2 fugacity ( fCO 2). We analyzed five fractions or phases of iron: soluble (<0.03 ?m), dissolved (<0.22 ?m), total dissolved (acidified dissolved, <0.22 ?m), labile (unfiltered), and total (acidified, unfiltered). From these, we also calculated non-labile iron, colloidal iron (0.03-0.22 ?m), and both labile and non-labile particulate iron (>0.22 ?m). Here, we describe iron distributions and the evolution of iron phases in the upper ocean during the experiment. We also present an iron budget accounting for horizontal and vertical dilution. At the time of our first sampling eight hours after fertilization was completed, total iron reached 8.6 nmol L -1 and dissolved iron was approximately 3 nmol L -1. Early in the experiment the dissolved iron phase decreased the most rapidly and by late day 6 the integrated dissolved iron (8.6 ?mol m -2) represented less than 10% of the initial addition (90-95 ?mol m -2). However at this same time the total integrated iron at the centre of the patch was still 52 ?mol m -2 or almost 60% of the calculated initial addition. By day 12,45% of the added iron (from both injections) could be accounted for in the patch. The half-life of total iron in the patch for the first injection was estimated to be less than 5 days if dilution is not considered, but more than 13 days if dilution is taken into account. The most notable change in iron percentages from one form to another occurred early in the first week of the experiment where the predominant phase shift was from the colloidal portion of dissolved iron to labile particulate iron that could have been biologically induced or simply aggregation of oxyhydroxides. This was immediately followed by a physical event resulting in a reduction in the non-labile particulate iron due to sinking out of the patch. The second infusion did not change the relative concentration of the various pools of iron as might be expected, but this was likely due to the fact that it was a much smaller injection than the first. The most pronounced change after the second infusion was the reduction in the labile particulate pool which coincided with one of the largest decreases in silicate observed during the entire experiment. In general the gradual decrease in the fraction of the 10 m colloidal iron as well as episodic losses of, or shifts in, integrated colloidal iron are thought to be the result of adsorption of colloidal iron to the plankton cell surfaces as well as aggregation of oxyhydroxides but could also be the result of utilization of colloidal iron by mixotrophic phytoplankton.

Wong, C. S.; Johnson, W. K.; Sutherland, N.; Nishioka, J.; Timothy, D. A.; Robert, M.; Takeda, S.

2006-10-01

60

Iron metabolism in bifidobacteria  

Microsoft Academic Search

Bifidobacteria are Gram-positive, anaerobic microaerophilic rods that are capable of internalizing ferrous iron at pH 5.0 and 6.5 when assayed in a post-logarithmic growth phase. Dependent upon iron concentration, iron uptake is most efficient in cells grown in a metal-depleted medium. There are two iron-uptake systems: one operating at low outside iron concentrations (1 to 20 ?M); and one operating

Anatoly Bezkorovainy; Eva Kot; Robin Miller-Catchpole; George Haloftis; Sergey Furmanov

1996-01-01

61

Effects of maternal iron nutrition during lactation on milk iron and rat neonatal iron status?3  

Microsoft Academic Search

We studied the milk iron content and iron status of lactating rats and their pups to investigatethe relationshipsbetween the iron concentrations of maternal diet and the iron content of milk, and that between the milk iron content and neonatal iron status. Three days after parturition lactating rats were divided into three groups and fed a control (250 ppm iron), a

Sunil G. Anaokar; Philip J. Garry

62

Genetics Home Reference: Iron-refractory iron deficiency anemia  

MedlinePLUS

... PubMed Recent literature OMIM Genetic disorder catalog Conditions > Iron-refractory iron deficiency anemia On this page: Description Genetic changes ... names Glossary definitions Reviewed July 2014 What is iron-refractory iron deficiency anemia? Iron-refractory iron deficiency ...

63

Iron Therapy for Preterm Infants  

PubMed Central

SYNOPSIS Preterm infants are at risk for both iron deficiency and iron overload. The role of iron in multiple organ functions suggests that iron supplementation is essential for the preterm infant. Conversely, the potential for iron overload and the poorly developed anti-oxidant measures in the preterm infant argues against indiscriminate iron supplementation in this population. The purpose of this article is to review the predisposing factors and consequences of iron deficiency and iron overload in the preterm infant, the current recommendation for iron supplementation and its appropriateness, and describe potential management strategies that strike a balance between iron deficiency and iron toxicity. PMID:19161863

Rao, Raghavendra; Georgieff, Michael K.

2009-01-01

64

Hemochromatosis: Iron Storage Disease  

MedlinePLUS

... this? Submit What's this? Submit Button CDC Features Hemochromatosis: Iron Storage Disease Language: English Español (Spanish) Share ... iron storage disease, and stay healthy. What Is Hemochromatosis? Hemochromatosis occurs when the body absorbs too much ...

65

Iron Chelation Therapy  

MedlinePLUS

... This is caused by a hereditary condition called hemochromatosis . Hereditary hemochromatosis is most common in people whose ancestors came ... supplements or multivitamins with iron. Patients with hereditary hemochromatosis may develop iron overload after a very small ...

66

Iron supplements (image)  

MedlinePLUS

The mineral iron is an essential nutrient for humans because it is part of blood cells, which carry oxygen to all body cells. There is no conclusive evidence that iron supplements contribute to heart attacks.

67

Iron and hepatitis C  

Microsoft Academic Search

Serum iron markers are often elevated in hepatitis C virus infection, particularly in African-American persons, although the\\u000a clinical significance of this finding remains unclear. Although hepatic iron is usually only mildly elevated in hepatitis\\u000a C virus, iron overload is associated with more advanced disease, nonresponse to interferon monotherapy, and increased risk\\u000a of hepatocellular carcinoma. Iron status does not predict response

James E. Nelson; Kris V. Kowdley

2004-01-01

68

Iron in diet  

MedlinePLUS

Diet - iron ... the body. Treatment consists of a low-iron diet, no iron supplements, and phlebotomy (blood removal) on ... The Food and Nutrition Board at the Institute of Medicine recommends the following: Infants and children Younger than 6 months: 0.27 milligrams ...

69

Introduction to iron works...The John Beard Memorial Symposium.  

PubMed

The Department of Nutritional Sciences at The Pennsylvania State University hosted a symposium entitled "Iron Works…The John Beard Memorial Symposium" in University Park, PA, on November 2, 2009. This one-day scientific symposium was held in honor of the late John Beard and was organized by Jere Haas, Shannon Kelleher, Terry Etherton, James Connor, and Gordon Jensen. The goal of the symposium was to discuss iron biology from a translational approach, encompassing molecular regulation, functional consequences of iron deficiency on neurophysiology and cognition through international and domestic interventions, and public health policy. Elizabeth Theil reviewed the biochemical regulation of iron homeostasis with a specific emphasis on ferritin, including its potential role as a dietary source of iron. James Connor discussed neuropsychological tests that, when coupled with imaging data, help identify brain regions that accumulate iron, which may be related to cognitive decline in the elderly. Betsy Lozoff shared her thoughts on effects of early iron deficiency on the brain and behavioral outcomes. Laura Murray-Kolb examined the functional consequences of iron deficiency in women of reproductive age. Rebecca Stoltzfus explored current interventions targeted at improving iron status in women and children in low-income countries. The scientific symposium closed with a discussion by Sean Lynch on the importance of understanding the effects of bioavailability on iron nutrition and the importance of integrating strategies to improve iron nutrition with other health measures, economic and social policies addressing poverty, as well as trade and agriculture. PMID:21346099

Kelleher, Shannon L; Haas, Jere D

2011-04-01

70

Iron, radiation, and cancer.  

PubMed Central

Increased iron content of cells and tissue may increase the risk of cancer. In particular, high available iron status may increase the risk of a radiation-induced cancer. There are two possible mechanisms for this effect: iron can catalyze the production of oxygen radicals, and it may be a limiting nutrient to the growth and development of a transformed cell in vivo. Given the high available iron content of the western diet and the fact that the world is changing to the western model, it is important to determine if high iron increases the risk of cancer. PMID:2269234

Stevens, R G; Kalkwarf, D R

1990-01-01

71

The production of iron carbide  

SciTech Connect

From start-up in 1994 to present, Nucor`s Iron Carbide plant has overcome many obstacles in achieving design production. Many of these impediments were due to flaws in equipment design. With the integration existing within the plant, limitations in any one system reduced the operating capacity of others. For this reason, as modifications were made and system capacities were increased, the need for additional modifications became apparent. Subsequently, operating practices, maintenance scheduling, employee incentives, and production objectives were continually adapted. This paper discusses equipment and design corrections and the quality issues that contributed to achieving the plant`s production capacity.

Anderson, K.M.; Scheel, J. [Nucor Iron Carbide, Inc., Point Lisas (Trinidad and Tobago)

1997-12-31

72

Mechanisms of mammalian iron homeostasis  

PubMed Central

Iron is vital for almost all organisms because of its ability to donate and accept electrons with relative ease. It serves as a cofactor for many proteins and enzymes necessary for oxygen and energy metabolism, as well as for several other essential processes. Mammalian cells utilize multiple mechanisms to acquire iron. Disruption of iron homeostasis is associated with various human diseases: iron deficiency resulting from defects in acquisition or distribution of the metal causes anemia; whereas iron surfeit resulting from excessive iron absorption or defective utilization causes abnormal tissue iron deposition, leading to oxidative damage. Mammals utilize distinct mechanisms to regulate iron homeostasis at the systemic and cellular levels. These involve the hormone hepcidin and iron regulatory proteins, which collectively ensure iron balance. This review outlines recent advances in iron regulatory pathways, as well as in mechanisms underlying intracellular iron trafficking, an important but less-studied area of mammalian iron homeostasis. PMID:22703180

Pantopoulos, Kostas; Porwal, Suheel Kumar; Tartakoff, Alan; Devireddy, L.

2012-01-01

73

Genomic insights into microbial iron oxidation and iron uptake strategies in extremely acidic environments.  

PubMed

This minireview presents recent advances in our understanding of iron oxidation and homeostasis in acidophilic Bacteria and Archaea. These processes influence the flux of metals and nutrients in pristine and man-made acidic environments such as acid mine drainage and industrial bioleaching operations. Acidophiles are also being studied to understand life in extreme conditions and their role in the generation of biomarkers used in the search for evidence of existing or past extra-terrestrial life. Iron oxidation in acidophiles is best understood in the model organism Acidithiobacillus ferrooxidans. However, recent functional genomic analysis of acidophiles is leading to a deeper appreciation of the diversity of acidophilic iron-oxidizing pathways. Although it is too early to paint a detailed picture of the role played by lateral gene transfer in the evolution of iron oxidation, emerging evidence tends to support the view that iron oxidation arose independently more than once in evolution. Acidic environments are generally rich in soluble iron and extreme acidophiles (e.g. the Leptospirillum genus) have considerably fewer iron uptake systems compared with neutrophiles. However, some acidophiles have been shown to grow as high as pH 6 and, in the case of the Acidithiobacillus genus, to have multiple iron uptake systems. This could be an adaption allowing them to respond to different iron concentrations via the use of a multiplicity of different siderophores. Both Leptospirillum spp. and Acidithiobacillus spp. are predicted to synthesize the acid stable citrate siderophore for Fe(III) uptake. In addition, both groups have predicted receptors for siderophores produced by other microorganisms, suggesting that competition for iron occurs influencing the ecophysiology of acidic environments. Little is known about the genetic regulation of iron oxidation and iron uptake in acidophiles, especially how the use of iron as an energy source is balanced with its need to take up iron for metabolism. It is anticipated that integrated and complex regulatory networks sensing different environmental signals, such as the energy source and/or the redox state of the cell as well as the oxygen availability, are involved. PMID:22050575

Bonnefoy, Violaine; Holmes, David S

2012-07-01

74

IRON IN MULTIPLE MYELOMA  

PubMed Central

Multiple myeloma is a non-curable B cell malignancy in which iron metabolism plays an important role. Patients with this disorder almost universally suffer from a clinically significant anemia, which is often symptomatic, and which is due to impaired iron utilization. Recent studies indicate that the proximal cause of dysregulated iron metabolism and anemia in these patients is cytokine-induced upregulation of hepcidin expression. Malignant myeloma cells are dependent on an increased influx of iron and therapeutic efforts are being made to target this requirement. The studies detailing the characteristics and biochemical abnormalities in iron metabolism causing anemia and the initial attempts to target iron therapeutically are described in this review. PMID:23879589

VanderWall, Kristina; Daniels-Wells, Tracy R; Penichet, Manuel; Lichtenstein, Alan

2013-01-01

75

Iron sensors and signals in response to iron deficiency.  

PubMed

The transcription of genes involved in iron acquisition in plants is induced under iron deficiency, but our understanding of iron sensors and signals remains limited. Iron Deficiency-responsive Element-binding Factor 1 (IDEF1) and Hemerythrin motif-containing Really Interesting New Gene- and Zinc-finger proteins (HRZs)/BRUTUS (BTS) have recently emerged as candidate iron sensors because of their functions as potent regulators of iron deficiency responses and their iron-binding properties. IDEF1 is a central transcriptional regulator of graminaceous genes involved in iron uptake and utilization, predominantly during the early stages of iron deficiency. HRZs/BTS are E3 ubiquitin ligases and negative regulators of iron deficiency responses in both graminaceous and non-graminaceous plants. Rice OsHRZ1 and OsHRZ2 are also potent regulators of iron accumulation. Characterizing these putative iron sensors also provides clues to understanding the nature of iron signals, which may involve ionized iron itself, other metals, oxygen, redox status, heme and iron-sulfur clusters, in addition to metabolites affected by iron deficiency. Systemic iron responses may also be regulated by phloem-mobile iron and its chelators such as nicotianamine. Iron sensors and signals will be identified by demonstration of signal transmission by IDEF1, HRZs/BTS, or unknown factors. PMID:24908504

Kobayashi, Takanori; Nishizawa, Naoko K

2014-07-01

76

Reactivity of Iron  

NSDL National Science Digital Library

In this laboratory excercise, students will be introduced to the oxidation / corrosion of iron from two different sources (flame and water). From the examination of corrosion from multiple sources, students will be able to compare and contrast the effects each has on the iron samples. Students will also be able to observe the effect of various material processing techniques has on the corrosive properties of iron.

Stoebe, Thomas G.

2008-10-28

77

35. GREY IRON TUMBLERS, IN THE GREY IRON FOUNDRY ROTATE ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

35. GREY IRON TUMBLERS, IN THE GREY IRON FOUNDRY ROTATE CASTINGS WITH SHOT TO REMOVE AND SURFACE OXIDES AND REMAINING EXCESS METALS. - Stockham Pipe & Fittings Company, Grey Iron Foundry, 4000 Tenth Avenue North, Birmingham, Jefferson County, AL

78

Plea for Iron Astrochemistry  

SciTech Connect

Iron is a key element and compound in living bodies. It is the most abundant refractory element and has the most stable nucleus in the Universe. Also, elemental Iron has a relevant abundance in the interstellar medium and dense clouds, it can be in gas phase or included in dust particles. During this talk, I shall explain why this special interest in Iron and shall give a brief explanation about its origin and the interstellar nucleosynthesis. After this I'll detail the rich chemistry that Iron can be involved in the interstellar medium, dense clouds with several species.

Mostefaoui, T. A.; Benmerad, B.; Kerkar, M. [Faculte des Sciences Exactes, Targa ou Zemmour, Universite de A. Mira, 6000 Bejaiea (Algeria)

2010-10-31

79

Physiology of Iron Metabolism  

PubMed Central

Summary A revolution occurred during the last decade in the comprehension of the physiology as well as in the physiopathology of iron metabolism. The purpose of this review is to summarize the recent knowledge that has accumulated, allowing a better comprehension of the mechanisms implicated in iron homeostasis. Iron metabolism is very fine tuned. The free molecule is very toxic; therefore, complex regulatory mechanisms have been developed in mammalian to insure adequate intestinal absorption, transportation, utilization, and elimination. ‘Ironomics’ certainly will be the future of the understanding of genes as well as of the protein-protein interactions involved in iron metabolism. PMID:25053935

Waldvogel-Abramowski, Sophie; Waeber, Gérard; Gassner, Christoph; Buser, Andreas; Frey, Beat M.; Favrat, Bernard; Tissot, Jean-Daniel

2014-01-01

80

Physics of iron  

SciTech Connect

This volume comprises papers presented at the AIRAPT Conference, June 28 to July 1993. The iron sessions at the meeting were identified as the Second Ironworkers Convention. The renewal of interest stems from advances in technologies in both diamond-anvil cell (DAC) and shock wave studies as well as from controversies arising from a lack of consensus among both experimentalists and theoreticians. These advances have produced new data on iron in the pressure-temperature regime of interest for phase diagrams and for temperatures of the core/mantle and inner-core/outer-core boundaries. Particularly interesting is the iron phase diagram inferred from DAC studies. A new phase, {beta}, with a {gamma}-{beta}-{epsilon} triple point at about 30 GPa and 1190 K, and possible sixth phase, {omega}, with an {epsilon}-{Theta}-melt triple point at about 190 GPa and 4000 K are deemed possible. The importance of the equation of state of iron in consideration of Earth`s heat budget and the origin of its magnetic field invoke the interest of theoreticians who argue on the basis of molecular dynamics and other first principles methods. While the major thrust of both meetings was on the physics of pure iron, there was notable contributions on iron alloys. Hydrogen-iron alloys, iron-sulfur liquids, and the comparability to rhenium in phase diagram studies are discussed. The knowledge of the physical properties of iron were increased by several contributions.

Anderson, O.

1993-10-01

81

Iron, Meat and Health  

PubMed Central

This article is a summary of the publication “Iron and Health” by the Scientific Advisory Committee on Nutrition (SACN) to the U.K. Government (2010), which reviews the dietary intake of iron and the impact of different dietary patterns on the nutritional and health status of the U.K. population. It concludes that several uncertainties make it difficult to determine dose-response relationships or to confidently characterize the risks associated with iron deficiency or excess. The publication makes several recommendations concerning iron intakes from food, including meat, and from supplements, as well as recommendations for further research. PMID:22254098

Geissler, Catherine; Singh, Mamta

2011-01-01

82

Hypersensitivity from intravenous iron products.  

PubMed

In the last several years, intravenous therapy with iron products has been more widely used. Although it has been a standard procedure in dialysis-associated anemia since the early 1990s, its use is expanding to a host of conditions associated with iron deficiency, especially young women with heavy uterine bleeding and pregnancy. Free iron is associated with unacceptable high toxicity inducing severe, hemodynamically significant symptoms. Subsequently, formulations that contain the iron as an iron carbohydrate nanoparticle have been designed. With newer formulations, including low-molecular-weight iron dextran, iron sucrose, ferric gluconate, ferumoxytol, iron isomaltoside, and ferric carboxymaltose, serious adverse events are rare. PMID:25017687

Bircher, Andreas J; Auerbach, Michael

2014-08-01

83

The case for iron  

Microsoft Academic Search

Excess major nutrients occur in offshore areas ranging from the tropical equatorial Pacific to the polar Antarctic. In spite of the great ecological differences in these environments, the authors believe they share a common trait: iron deficiency. Here they present the case of iron; they point out that all of these areas are far from Fe-rich terrestrial sources and that

JOHN H. MARTIN; R. MICHAEL GORDON; STEVE E. FITZWATER

1991-01-01

84

49 CFR 192.369 - Service lines: Connections to cast iron or ductile iron mains.  

...false Service lines: Connections to cast iron or ductile iron mains. 192.369...369 Service lines: Connections to cast iron or ductile iron mains. (a) Each service line connected to a cast iron or ductile iron main must be...

2014-10-01

85

21 CFR 310.518 - Drug products containing iron or iron salts.  

Code of Federal Regulations, 2012 CFR

...false Drug products containing iron or iron salts. 310.518 Section 310.518 Food...518 Drug products containing iron or iron salts. Drug products containing elemental iron or iron salts as an active ingredient in solid oral...

2012-04-01

86

21 CFR 310.518 - Drug products containing iron or iron salts.  

Code of Federal Regulations, 2011 CFR

...false Drug products containing iron or iron salts. 310.518 Section 310.518 Food...518 Drug products containing iron or iron salts. Drug products containing elemental iron or iron salts as an active ingredient in solid oral...

2011-04-01

87

21 CFR 310.518 - Drug products containing iron or iron salts.  

Code of Federal Regulations, 2010 CFR

...false Drug products containing iron or iron salts. 310.518 Section 310.518 Food...518 Drug products containing iron or iron salts. Drug products containing elemental iron or iron salts as an active ingredient in solid oral...

2010-04-01

88

21 CFR 310.518 - Drug products containing iron or iron salts.  

Code of Federal Regulations, 2013 CFR

...false Drug products containing iron or iron salts. 310.518 Section 310.518 Food...518 Drug products containing iron or iron salts. Drug products containing elemental iron or iron salts as an active ingredient in solid oral...

2013-04-01

89

21 CFR 310.518 - Drug products containing iron or iron salts.  

...false Drug products containing iron or iron salts. 310.518 Section 310.518 Food...518 Drug products containing iron or iron salts. Drug products containing elemental iron or iron salts as an active ingredient in solid oral...

2014-04-01

90

How Is Iron-Deficiency Anemia Treated?  

MedlinePLUS

... page from the NHLBI on Twitter. How Is Iron-Deficiency Anemia Treated? Treatment for iron-deficiency anemia ... cells, hemoglobin, and iron. Dietary Changes and Supplements Iron You may need iron supplements to build up ...

91

Iron economy in Chlamydomonas reinhardtii  

PubMed Central

While research on iron nutrition in plants has largely focused on iron-uptake pathways, photosynthetic microbes such as the unicellular green alga Chlamydomonas reinhardtii provide excellent experimental systems for understanding iron metabolism at the subcellular level. Several paradigms in iron homeostasis have been established in this alga, including photosystem remodeling in the chloroplast and preferential retention of some pathways and key iron-dependent proteins in response to suboptimal iron supply. This review presents our current understanding of iron homeostasis in Chlamydomonas, with specific attention on characterized responses to changes in iron supply, like iron-deficiency. An overview of frequently used methods for the investigation of iron-responsive gene expression, physiology and metabolism is also provided, including preparation of media, the effect of cell size, cell density and strain choice on quantitative measurements and methods for the determination of metal content and assessing the effect of iron supply on photosynthetic performance. PMID:24032036

Glaesener, Anne G.; Merchant, Sabeeha S.; Blaby-Haas, Crysten E.

2013-01-01

92

Correcting Iron Deficiencies in Soybean with Foliar Iron Fertilizer  

E-print Network

Correcting Iron Deficiencies in Soybean with Foliar Iron Fertilizer Kevin Bronson, Calvin TrostleH soils in our region is conducive to "lime-induced chlorosis" or iron (Fe) deficiency in soybean. High p indicators of iron deficiency for chlorotic and green soybean, Ropesville, Texas, 2001 Soil type Soil Ca (ppm

Mukhtar, Saqib

93

Formation and Release Behavior of Iron Corrosion Products under the Influence of Bacterial Communities in a Simulated Water Distribution System  

EPA Science Inventory

Understanding the effects of biofilm on the iron corrosion, iron release and associated corrosion by-products is critical for maintaining the water quality and the integrity of drinking water distribution system (DWDS). In this work, iron corrosion experiments under sterilized a...

94

Iron overload and chelation therapy in myelodysplastic syndromes.  

PubMed

Iron overload remains a concern in MDS patients especially those requiring recurrent blood transfusions. The consequence of iron overload may be more relevant in patients with low and intermediate-1 risk MDS who may survive long enough to experience such manifestations. It is a matter of debate whether this overload has time to yield organ damage, but it is quite evident that cellular damage and DNA genotoxic effect are induced. Iron overload may play a critical role in exacerbating pre-existing morbidity or even unmask silent ones. Under these circumstances, iron chelation therapy could play an integral role in the management of these patients. This review entails an in depth analysis of iron overload in MDS patients; its pathophysiology, effect on survival, associated risks and diagnostic options. It also discusses management options in relation to chelation therapy used in MDS patients and the impact it has on survival, hematologic response and organ function. PMID:24529413

Temraz, Sally; Santini, Valeria; Musallam, Khaled; Taher, Ali

2014-07-01

95

Molecular control of vertebrate iron homeostasis by iron regulatory proteins  

PubMed Central

Both deficiencies and excesses of iron represent major public health problems throughout the world. Understanding the cellular and organismal processes controlling iron homeostasis is critical for identifying iron-related diseases and in advancing the clinical treatments for such disorders of iron metabolism. Iron regulatory proteins (IRPs) 1 and 2 are key regulators of vertebrate iron metabolism. These RNA binding proteins post-transcriptionally control the stability or translation of mRNAs encoding proteins involved in iron homeostasis thereby controlling the uptake, utilization, storage or export of iron. Recent evidence provides insight into how IRPs selectively control the translation or stability of target mRNAs, how IRP RNA binding activity is controlled by iron-dependent and iron-independent effectors, and the pathological consequences of dysregulation of the IRP system. PMID:16872694

Wallander, Michelle L.; Leibold, Elizabeth A.; Eisenstein, Richard S.

2008-01-01

96

Iron in Cereal  

NSDL National Science Digital Library

Is there really iron in breakfast cereal? This material is part of a series of hands-on science activities designed to arouse student interest. Here students investigate the removal of iron from a box of high-iron content breakfast cereal. The activity includes a description, a list of science process skills being covered, complex reasoning strategies that are used, and a compilation of national science standards about this activity. Also provided are content topics, a list of necessary supplies and instructions to perform the activity, and presentation techniques. An explanation of the content of each activity and assessment suggestions are provided. Copyright 2005 Eisenhower National Clearinghouse

Mid-continent Research for Education and Learning (McREL); Jacobs, Steve

2004-01-01

97

Molecular Structure of Iron Monoxide  

NSDL National Science Digital Library

Iron monoxide is an odorless black powder. Technologies and uses of iron and iron oxide powders have progressed steadily. Synthetic iron oxide powders are used primarily for pigmentary and magnetic properties. These powders are inexpensive to make and are used to color concrete products, paints, plastics and other media.

2003-06-04

98

Saugus Iron Works Blast Furnace  

USGS Multimedia Gallery

A view of the Saugus Iron Works blast furnace, which smelted the iron from limonite, an iron ore. The limonite formed in nearby bogs, and was heated in the blast furnace until the iron melted and ran out the bottom of the furnace....

99

Limonite at Saugus Iron Works  

USGS Multimedia Gallery

A specimen of limonite, used in the iron smelting process. Limonite is a well-known iron ore that has been mined for iron for many thousands of years. At the Saugus Iron Works, the limonite was found in nearby bogs....

100

Iron fertilization of kentucky bluegrass  

Microsoft Academic Search

Iron applications are sometimes used to enhance the color (darker green) of turfgrass stands even when iron is not deficient. A study was conducted to determine the feasibility of replacing a portion of the total yearly N applied to Kentucky bluegrass (Poa pratensis L.) with iron. Turfgrass response to iron chelate (Sequestrene 330) applications at 2.2 kg Fe ha in

David J. Wehner; Jean E. Haley

1990-01-01

101

Reactive iron in marine sediments  

NASA Technical Reports Server (NTRS)

The influence of reactive iron oxides on sediment pore-water chemistry is considered in detail. A carefully calibrated extraction scheme is used to determine the depth distributions of reactive iron phases at two very different localities: the relatively iron-rich Mississippi Delta and the relatively iron-poor FOAM site in Long Island Sound. Closed system incubations are used to characterize the rates of reaction between sulfide and both naturally occurring and pure iron mineral phases. Rates of iron liberation to pore solution are measured in the presence and absence of sulfate reduction, and the origin of dissolved iron in organic-rich sediments is speculated upon.

Canfield, Donald E.

1989-01-01

102

Application of iron magnetic nanoparticles in protein immobilization.  

PubMed

Due to their properties such as superparamagnetism, high surface area, large surface-to-volume ratio, easy separation under external magnetic fields, iron magnetic nanoparticles have attracted much attention in the past few decades. Various modification methods have been developed to produce biocompatible magnetic nanoparticles for protein immobilization. This review provides an updated and integrated focus on the fabrication and characterization of suitable magnetic iron nanoparticle-based nano-active materials for protein immobilization. PMID:25093986

Xu, Jiakun; Sun, Jingjing; Wang, Yuejun; Sheng, Jun; Wang, Fang; Sun, Mi

2014-01-01

103

An Ancient Gauge for Iron  

NSDL National Science Digital Library

The iron regulatory proteins IRP1 and IRP2 are critical to the import, export, and sequestration of iron for achievement of the cytosolic concentrations needed to support the synthesis of iron-binding proteins and for prevention of unfavorable iron-dependent oxidation events in mammalian cells. This perspective discusses reports by Vashisht et al. and Salahudeen et al. that human cells gauge cellular iron and concomitantly alter the activity of IRPs through a mechanism that depends on the protein FBXL5.

Tracey Rouault (National Institute of Child Health and Human Development;Molecular Medicine Program)

2009-10-30

104

Iron and the immune system  

Microsoft Academic Search

Iron and immunity are closely linked: firstly by the fact that many of the genes\\/proteins involved in iron homoeostasis play\\u000a a vital role in controlling iron fluxes such that bacteria are prevented from utilising iron for growth; secondly, cells of\\u000a the innate immune system, monocytes, macrophages, microglia and lymphocytes, are able to combat bacterial insults by carefully\\u000a controlling their iron

Roberta J. WardRobert; Robert R. Crichton; Deanna L. Taylor; Laura Della Corte; Surjit K. Srai; David T. Dexter

2011-01-01

105

Iron in my cereal  

NSDL National Science Digital Library

This activity is a hands on activity where students will gather information on their findings about iron in different cereals. Then use their finding and give reasonings of the differences and similarities.

Macias, Anne H.

106

Iron Dextran Injection  

MedlinePLUS

Iron dextran injection comes as a solution (liquid) to inject into the muscles of the buttocks or intravenously (into a vein) by a doctor or nurse in a medical facility. Your doctor will determine ...

107

Possible involvement of iron-induced oxidative insults in neurodegeneration.  

PubMed

Involvement of iron in the development of neurodegenerative disorders has long been suggested, and iron that cannot be stored properly is suggested to induce iron toxicity. To enhance iron uptake and suppress iron storage in neurons, we generated transgenic (Tg) mice expressing iron regulatory protein 2 (IRP2), a major regulator of iron metabolism, in a neuron-specific manner. Although very subtle, IRP2 was expressed in all regions of brain examined. In the Tg mice, mitochondrial oxidative insults were observed including generation of 4-hydroxynonenal modified proteins, which appeared to be removed by a mitochondrial quality control protein Parkin. Inter-crossing of the Tg mice to Parkin knockout mice perturbed the integrity of neurons in the substantia nigra and provoked motor symptoms. These results suggest that a subtle, but chronic increase in IRP2 induces mitochondrial oxidative insults and accelerates neurodegeneration in a mouse model of Parkinson's disease. Thus, the IRP2 Tg may be a useful tool to probe the roles of iron-induced mitochondrial damages in neurodegeraration research. PMID:25549542

Asano, Takeshi; Koike, Masato; Sakata, Shin-Ichi; Takeda, Yukiko; Nakagawa, Tomoko; Hatano, Taku; Ohashi, Satoshi; Funayama, Manabu; Yoshimi, Kenji; Asanuma, Masato; Toyokuni, Shinya; Mochizuki, Hideki; Uchiyama, Yasuo; Hattori, Nobutaka; Iwai, Kazuhiro

2015-02-19

108

Iron homeostasis in the liver  

PubMed Central

Iron is an essential nutrient that is tightly regulated. A principal function of the liver is the regulation of iron homeostasis. The liver senses changes in systemic iron requirements and can regulate iron concentrations in a robust and rapid manner. The last 10 years have led to the discovery of several regulatory mechanisms in the liver which control the production of iron regulatory genes, storage capacity, and iron mobilization. Dysregulation of these functions leads to an imbalance of iron, which is the primary causes of iron-related disorders. Anemia and iron overload are two of the most prevalent disorders worldwide and affect over a billion people. Several mutations in liver-derived genes have been identified, demonstrating the central role of the liver in iron homeostasis. During conditions of excess iron, the liver increases iron storage and protects other tissues, namely the heart and pancreas from iron-induced cellular damage. However, a chronic increase in liver iron stores results in excess reactive oxygen species production and liver injury. Excess liver iron is one of the major mechanisms leading to increased steatohepatitis, fibrosis, cirrhosis, and hepatocellular carcinoma. PMID:23720289

Anderson, Erik R; Shah, Yatrik M

2014-01-01

109

Iron in the brain  

NASA Astrophysics Data System (ADS)

The results of our studies of iron in three brain structures, substantia nigra (SN), globus pallidus (GP), and hippocampus (Hip), are presented. Mössbauer spectroscopy, electron microscopy and ELISA (enzyme-linked immuno-absorbent assay) were applied. Mössbauer studies show that most of the iron in the brain is ferritin-like. The concentration of iron is similar in SN and GP, but less than half of this in Hip. ELISA studies showed that the H/L ratio of ferritin in SN and GP is also similar, but is about three times higher in Hip. These results suggest that the role of iron in SN and GP may be different from that in Hip. Electron microscopy shows that the diameters of the ferritin iron cores in the brain are smaller that in the liver (3.5 ± 0.5 nm vs. 6.0 ± 0.5 nm). Mössbauer studies yield the ratio between the concentration of iron in control and parkinsonian SN as 1.00 ± 0.13.

Galazka-Friedman, Jolanta; Friedman, Andrzej; Bauminger, Erika R.

2009-02-01

110

Iron-activated iron uptake: A positive feedback loop mediated by iron regulatory protein 1  

Microsoft Academic Search

The love-hate relationship between iron and living matter has generated mechanisms to maintain iron concentration in a narrow range, above and below which deleterious effects occur. At the cellular level, iron homeostasis is accomplished by the activity of the IRP proteins, which, under conditions of iron depletion, up-regulate the expression of the iron acquisition proteins TfR and DMT1. It has

Marto T. Núñez; Claudia Núñez-Millacura; Victoria Tapia; Patricia Muñoz; Dora Mazariegos; Miguel Arredondo; Pablo Muñoz; Casilda Mura; Ricardo B. Maccioni

2003-01-01

111

Oxidation state variation under -irradiation in an iron-bearing soda lime glass system This article has been downloaded from IOPscience. Please scroll down to see the full text article.  

E-print Network

wastes in glassy matrix. Despite this political decision, important scientific issues remain unclear. One to diminish this migration consists in doping the oxide glass with transition metals like iron. As the dopant of ferrous iron to total iron ratio as a function of the iron content and of the dose integrated have been

112

Iron assimilation and transcription factor controlled synthesis of riboflavin in plants.  

PubMed

Iron homeostasis is vital for many cellular processes and requires a precise regulation. Several iron efficient plants respond to iron starvation with the excretion of riboflavin and other flavins. Basic helix-loop-helix transcription factors (TF) are involved in the regulation of many developmental processes, including iron assimilation. Here we describe the isolation and characterisation of two Arabidopsis bHLH TF genes, which are strongly induced under iron starvation. Their heterologous ectopic expression causes constitutive, iron starvation independent excretion of riboflavin. The results show that both bHLH TFs represent an essential component of the regulatory pathway connecting iron deficiency perception and riboflavin excretion and might act as integrators of various stress reactions. PMID:17260143

Vorwieger, A; Gryczka, C; Czihal, A; Douchkov, D; Tiedemann, J; Mock, H-P; Jakoby, M; Weisshaar, B; Saalbach, I; Bäumlein, H

2007-06-01

113

A Novel Iron-Regulated Metal Transporter from Plants Identified by Functional Expression in Yeast  

Microsoft Academic Search

Iron is an essential nutrient for virtually all organisms. The IRT1 (iron-regulated transporter) gene of the plant Arabidopsis thaliana, encoding a probable Fe(II) transporter, was cloned by functional expression in a yeast strain defective for iron uptake. Yeast expressing IRT1 possess a novel Fe(II) uptake activity that is strongly inhibited by Cd. IRT1 is predicted to be an integral membrane

David Eide; Margaret Broderius; Janette Fett; Mary Lou Guerinot

1996-01-01

114

Iron metabolism: The low-molecular-mass iron pool  

Microsoft Academic Search

Summary This review examines various aspects of iron metabolism in mammalian and bacterial cells which support the hypothesis of the existence and the biological significance of an intracellular pool of low-molecular mass iron complexes.

M. Fontecave; J. L. Pierre

1991-01-01

115

Iron-sensitive fluorescent probes: monitoring intracellular iron pools.  

PubMed

Several iron-sensitive fluorophores have been investigated in a range of cell types in order to quantify iron(ii) levels in the cytosol and the cytoplasm. Both iron(ii) and iron(iii) cause fluorescence quenching of these probes and changes in cytosolic iron levels can be monitored in a reproducible manner. However the precise quantification of iron(ii) in the cytosol is complicated by the uncertainty of the structure of many of the quenched species that exist under in vivo conditions. Precise knowledge of these structures is essential for quantitative purposes. The lysosomal and mitochondrial iron pools have only been the subject of relatively few studies at the time of writing. Calcein-AM has been widely adopted for the monitoring of changes in iron levels in a range different cell types. PMID:25315476

Ma, Yongmin; Abbate, V; Hider, R C

2015-02-11

116

Coming into View: Eukaryotic Iron Chaperones and Intracellular Iron Delivery*  

PubMed Central

Eukaryotic cells contain hundreds of metalloproteins, and ensuring that each protein receives the correct metal ion is a critical task for cells. Recent work in budding yeast and mammalian cells has uncovered a system of iron delivery operating in the cytosolic compartment that involves monothiol glutaredoxins, which bind iron in the form of iron-sulfur clusters, and poly(rC)-binding proteins, which bind Fe(II) directly. In yeast cells, cytosolic monothiol glutaredoxins are required for the formation of heme and iron-sulfur clusters and the metallation of some non-heme iron enzymes. Poly(rC)-binding proteins can act as iron chaperones, delivering iron to target non-heme enzymes through direct protein-protein interactions. Although the molecular details have yet to be explored, these proteins, acting independently or together, may represent the basic cellular machinery for intracellular iron delivery. PMID:22389494

Philpott, Caroline C.

2012-01-01

117

Iron availability, cellular iron quotas, and nitrogen fixation in Trichodesmium  

Microsoft Academic Search

Iron availability is suggested to be a primary factor limiting nitrogen fixation in the oceans. This hypothesis is principally based on cost-benefit analyses of iron quotas in the dominant nitrogen-fixing cyanobacteria,Trichodesmium spp., in the contemporary oceans. Although previous studies with Trichodesmium have indicated that iron availability enhanced nitrogen fixation and photosynthesis, no clear relationship has been reported between cellular iron

Ilana Berman-Frank; Jay T. Cullen; Yeala Shaked; Robert M. Sherrell; Paul G. Falkowski

2001-01-01

118

Oral iron therapy with ferrous fumarate and polysaccharide iron complex.  

PubMed

Oral iron replacement therapy with Chromagen, containing ferrous fumarate, and Niferex, containing polysaccharide iron complex, can successfully maintain hematologic and iron indices in dialysis clients and demonstrated fewer adverse effects in selected clients. Their multiple ingredient dose forms, which further support erythropoiesis, and their possible decrease in distressing side effects should enhance client compliance, making these two drugs excellent alternatives to traditional iron therapies. PMID:1627011

Glassman, E

1992-06-01

119

Iron regulatory proteins and their role in controlling iron metabolism.  

PubMed

Cellular iron homeostasis is regulated by post-transcriptional feedback mechanisms, which control the expression of proteins involved in iron uptake, release and storage. Two cytoplasmic proteins with mRNA-binding properties, iron regulatory proteins 1 and 2 (IRP1 and IRP2) play a central role in this regulation. Foremost, IRPs regulate ferritin H and ferritin L translation and thus iron storage, as well as transferrin receptor 1 (TfR1) mRNA stability, thereby adjusting receptor expression and iron uptake via receptor-mediated endocytosis of iron-loaded transferrin. In addition splice variants of iron transporters for import and export at the plasma-membrane, divalent metal transporter 1 (DMT1) and ferroportin are regulated by IRPs. These mechanisms have probably evolved to maintain the cytoplasmic labile iron pool (LIP) at an appropriate level. In certain tissues, the regulation exerted by IRPs influences iron homeostasis and utilization of the entire organism. In intestine, the control of ferritin expression limits intestinal iron absorption and, thus, whole body iron levels. In bone marrow, erythroid heme biosynthesis is coordinated with iron availability through IRP-mediated translational control of erythroid 5-aminolevulinate synthase mRNA. Moreover, the translational control of HIF2? mRNA in kidney by IRP1 coordinates erythropoietin synthesis with iron and oxygen supply. Besides IRPs, body iron absorption is negatively regulated by hepcidin. This peptide hormone, synthesized and secreted by the liver in response to high serum iron, downregulates ferroportin at the protein level and thereby limits iron absorption from the diet. Hepcidin will not be discussed in further detail here. PMID:25306858

Kühn, Lukas C

2015-02-11

120

Anemia caused by low iron - children  

MedlinePLUS

Anemia - iron deficiency - children ... able to absorb iron well, even though the child is eating enough iron Slow blood loss over ... bleeding in the digestive tract Iron deficiency in children can also be related to lead poisoning .

121

Iron deficiency and iron fortified foods—a review  

Microsoft Academic Search

Iron is a mineral that is necessary for producing red blood cells and for redox processes. Iron deficiency is considered to be the commonest worldwide nutritional deficiency and affects approximately 20% of the world population. Lack of iron may lead to unusual tiredness, shortness of breath, a decrease in physical performance, and learning problems in children and adults, and may

N Mart??nez-Navarrete; M. M Camacho; J Mart??nez-Lahuerta; J Mart??nez-Monzó; P Fito

2002-01-01

122

Hydroxamate recognition during iron transport from hydroxamate-iron chelates  

Microsoft Academic Search

Kinetics of radioactive iron transport from three structurally different ; secondary hydroxandate-iron chelates (schizokineniron, produced by Bacillus ; megaterium ATCC 19213; Desferaliron, produced by an actinomycete; and aerobactin-; iron, produced by Aerobacter aerogenes 62-1) revealed that B. megateriurm SK 11 ; (a mutant that cannot synthesize schizokinen) has a specific transport system for ; utilization of ferric hydroxamates with a

A. H. Haydon; W. B. Davis; E. L. Arceneaux; B. R. Byers

1973-01-01

123

Formation and occurrence of biogenic iron-rich minerals  

NASA Astrophysics Data System (ADS)

Iron cycling in the Earth's crust depends on redox reactions, which often trigger the precipitation and dissolution of Fe-rich minerals. Microbial activity is also an integral part of iron cycling, through carbon fixation, respiration and passive sorption reactions. Iron oxides formed in close association with bacteria (either as internal or external precipitates) are referred to as biogenic minerals. They form in several types of environments on Earth, from freshwater to marine systems, aquifers, soils and mining impacted systems. Biogenic iron oxides generally occur as nanocrystals and show a wide range of morphology and mineralogy. These minerals form as a result of the direct metabolic activity of bacteria or as a result of passive sorption and nucleation reactions. The metabolic activity of acidophilic and neutrophilic iron-oxidizing bacteria under oxic conditions promotes the oxidation of Fe(II) to Fe(III) and the precipitation of biogenic iron oxides as extracellular precipitates near or on the bacterial cells. Iron oxidation under anoxic conditions can also occur, as a result of the activity of nitrate-reducers and photoautotrophic bacteria using Fe(II) as an electron donor. Secondary Fe-oxide formation has been reported during the microbial reduction of iron oxides. Passive Fe sorption and nucleation onto bacterial cell walls represents another important mechanism leading to iron oxide formation. The surface reactivity of the bacterial surface under environmental pH conditions confers a net negative charge to the cell wall, which leads to the binding of soluble iron and eventually to the precipitation of iron oxides under saturation conditions. Extracellular polymers produced by bacteria can act as a template for iron sorption and Fe-oxide nucleation. Intracellular iron oxide formation has been observed in natural environments. Magnetotactic bacteria produce intracellular magnetosomes, occurring as chains of magnetite crystals within the cells, and an unidentified iron-rich mineral phase forms inside Shewanella cells during the anaerobic reduction of ferrihydrite. Several studies have clearly shown that biogenic iron oxides form in present-day environments, but they might also be important components of ancient geological formations, such as banded-iron formations (BIF). BIF formation is still being debated, but there is now strong evidence that bacteria, more specifically, phototrophic iron oxidizers and possibly iron reducers might have been involved. Biogenic iron oxides represent a potential tool in the search for past and present life on Earth and other planetary systems. Despite the promising use of Fe-isotopes and magnetosomes, there is still no clear proof that they can form only as a result of biological activity. In fact, Fe isotope fractionation of abiotic iron oxides is often similar to that of biogenic oxides and the specific mineralogical characteristics of magnetite crystals present inside magnetotactic bacteria can be reproduced under abiotic conditions. In summary, the role of bacteria in iron cycling has been the focus of several studies in the last few decades, but clearly, more research is needed in order to fully assess the role of microorganisms in their formation.

Fortin, Danielle; Langley, Sean

2005-09-01

124

Iron in Infection and Immunity  

PubMed Central

Iron is an essential nutrient for both humans and pathogenic microbes. Because of its ability to exist in one of two oxidation states, iron is an ideal redox catalyst for diverse cellular processes including respiration and DNA replication. However, the redox potential of iron also contributes to its toxicity, thus iron concentration and distribution must be carefully controlled. Given the absolute requirement for iron by virtually all human pathogens, an important facet of the innate immune system is to limit iron availability to invading microbes in a process termed nutritional immunity. Successful human pathogens must therefore possess mechanisms to circumvent nutritional immunity in order to cause disease. In this review, we discuss regulation of iron metabolism in the setting of infection and delineate strategies used by human pathogens to overcome iron-withholding defenses. PMID:23684303

Cassat, James E.; Skaar, Eric P.

2013-01-01

125

Iron Meteorite on Mars  

NASA Technical Reports Server (NTRS)

NASA's Mars Exploration Rover Opportunity has found an iron meteorite on Mars, the first meteorite of any type ever identified on another planet. The pitted, basketball-size object is mostly made of iron and nickel. Readings from spectrometers on the rover determined that composition. Opportunity used its panoramic camera to take the images used in this approximately true-color composite on the rover's 339th martian day, or sol (Jan. 6, 2005). This composite combines images taken through the panoramic camera's 600-nanometer (red), 530-nanometer (green), and 480-nanometer (blue) filters.

2005-01-01

126

Iron accumulation and neurotoxicity in cortical cultures treated with holotransferrin.  

PubMed

Nonheme iron accumulates in CNS tissue after ischemic and hemorrhagic insults and may contribute to cell loss. The source of this iron has not been precisely defined. After blood-brain barrier disruption, CNS cells may be exposed to plasma concentrations of transferrin-bound iron (TBI), which exceed that in the CSF by over 50-fold. In this study, the hypothesis that these concentrations of TBI produce cell iron accumulation and neurotoxicity was tested in primary cortical cultures. Treatment with 0.5-3mg/ml holotransferrin for 24h resulted in the loss of 20-40% of neurons, associated with increases in malondialdehyde, ferritin, heme oxygenase-1, and iron; transferrin receptor-1 expression was reduced by about 50%. Deferoxamine, 2,2'-bipyridyl, Trolox, and ascorbate prevented all injury, but apotransferrin was ineffective. Cell TBI accumulation was significantly reduced by deferoxamine, 2,2'-bipyridyl, and apotransferrin, but not by ascorbate or Trolox. After treatment with (55)Fe-transferrin, approximately 40% of cell iron was exported within 16h. Net export was increased by deferoxamine and 2,2'-bipyridyl, but not by apotransferrin. These results suggest that downregulation of transferrin receptor-1 expression is insufficient to prevent iron-mediated death when neurons are exposed to plasma concentrations of TBI. Chelator therapy may be beneficial for acute CNS injuries associated with loss of blood-brain barrier integrity. PMID:21939754

Chen-Roetling, Jing; Liu, Wenpei; Regan, Raymond F

2011-12-01

127

Optimum arrangement for the neutron dose rate of an iron-polyethylene shielding system  

SciTech Connect

Integral shielding experiments using iron-polyethylene slab shields were carried out to determine an optimum arrangement for the neutron dose rate. The total thickness of the iron slabs was fixed at 32 cm, while several thicknesses of polyethylene slabs were employed as a parameter. Some measured data were analyzed by the Mone Carlo code MORSE-CG with the splitting technique.

Ueki, K.; Namito, Y.

1987-05-01

128

Enzymes of respiratory iron oxidation  

SciTech Connect

This report focuses on the progress made in three areas of research concerned with enzymes involved in respiratory iron oxidation. The three areas are as follows: development of an improved procedure for the routine large scale culture of iron oxidizing chemolithotrophs based on the in-situ electrolysis of the soluble iron in the growth medium; to perform iron oxidation kinetic studies on whole cells using the oxygen electrode; and to identify, separate, purify, and characterize the individual cellular components.

Blake, R. II.

1991-01-01

129

An update on iron physiology  

Microsoft Academic Search

Iron is an essential micronutrient, as it is required for adequate erythropoietic function, oxidative metabolism and cellular immune responses. Although the absorption of dietary iron (1-2 mg\\/d) is regulated tightly, it is just balanced with losses. Therefore, internal turnover of iron is essential to meet the requirements for erythropoiesis (20-30 mg\\/d). Increased iron requirements, limited external supply, and increased blood

Manuel Muñoz; Isabel Villar; José Antonio García-Erce; Javier P Gisbert; Fernando Gomollón

130

Iron in Your Diet Iron is a vital mineral for health. Too little iron can cause iron deficiency anemia. This can  

E-print Network

Iron in Your Diet Iron is a vital mineral for health. Too little iron can cause iron deficiency common and is seen more often in the elderly and in teenagers. Iron needs vary with age and gender. The need for iron increases during growth periods (pregnancy, infancy, childhood, and teen years

Wisconsin at Madison, University of

131

Iron cofactor assembly in plants.  

PubMed

Iron is an essential element for all photosynthetic organisms. The biological use of this transition metal is as an enzyme cofactor, predominantly in electron transfer and catalysis. The main forms of iron cofactor are, in order of decreasing abundance, iron-sulfur clusters, heme, and di-iron or mononuclear iron, with a wide functional range. In plants and algae, iron-sulfur cluster assembly pathways of bacterial origin are localized in the mitochondria and plastids, where there is a high demand for these cofactors. A third iron-sulfur cluster assembly pathway is present in the cytosol that depends on the mitochondria but not on plastid assembly proteins. The biosynthesis of heme takes place mainly in the plastids. The importance of iron-sulfur cofactors beyond photosynthesis and respiration has become evident with recent discoveries of novel iron-sulfur proteins involved in epigenetics and DNA metabolism. In addition, increased understanding of intracellular iron trafficking is opening up research into how iron is distributed between iron cofactor assembly pathways and how this distribution is regulated. PMID:24498975

Balk, Janneke; Schaedler, Theresia A

2014-01-01

132

IRON FILE SYSTEMS Vijayan Prabhakaran  

E-print Network

that measures their Internal RObustNess (IRON), which includes both failure detection and recovery techniquesIRON FILE SYSTEMS by Vijayan Prabhakaran B.E. Computer Sciences (Regional Engineering College;v Abstract IRON FILE SYSTEMS Vijayan Prabhakaran Disk drives are widely used as a primary medium

Liblit, Ben

133

IRON FILE SYSTEMS Vijayan Prabhakaran  

E-print Network

that measures their Internal RObustNess (IRON), which includes both failure detection and recovery techniquesIRON FILE SYSTEMS by Vijayan Prabhakaran B.E. Computer Sciences (Regional Engineering College #12; v Abstract IRON FILE SYSTEMS Vijayan Prabhakaran Disk drives are widely used as a primary medium

Arpaci-Dusseau, Andrea

134

Iron and immunity: immunological consequences of iron deficiency and overload  

PubMed Central

The influence of iron on immune function has been long appreciated. However, the molecular basis for this interaction is less well understood. Recently, there have been several important advances that have shed light on the mechanisms that regulate mammalian iron metabolism. The new insights provide a conceptual framework for understanding and manipulating the cross-talk between iron homeostasis and the immune system. This article will review what is currently known about how disturbances of iron metabolism can affect immunity and how activation of the immune system can lead to alterations in iron balance. PMID:20878249

Cherayil, Bobby J.

2011-01-01

135

Novel approaches and application of contemporary sensory evaluation practices in iron fortification programs  

NASA Technical Reports Server (NTRS)

Iron deficiency is the leading nutritional deficiency in the U.S. and the rest of the world, with its highest prevalences in the developing world. Iron fortification of food has been proposed as a strategy to reduce the high prevalence of iron deficiency. Poor consumer acceptance, unacceptable taste, and discoloration of the iron-fortified foods have been frequently listed as causes of unsuccessful iron fortification programs. An excellent prospect for improving consumer acceptance of iron-fortified foods is the incorporation of a thorough, organized, and unified approach to sensory evaluation practices into iron fortification programs for product optimization. The information gained from systematic sensory evaluation allows for the manipulation of the sensory attributes, and thus improvement of the sensory properties of the fortified food. However, iron fortification programs have not systematically measured the effect of fortification on the sensory quality of the food. Because sensory evaluation is an important criterion in successful iron fortification, an integrated approach is necessary. Therefore, nutritionists and sensory scientists should work closely with each other to select the most suitable sensory tests and methods. The objectives of this article are to: (1) critically review and discuss some traditional and contemporary approaches and applications of sensory evaluation practices in iron fortification programs, and (2) demonstrate the importance of incorporating a multidisciplinary, systematic sensory evaluation approach in iron fortification programs.

Bovell-Benjamin, Adelia C.; Guinard, Jean-Xavier

2003-01-01

136

The iron stimulon and fur regulon of Geobacter sulfurreducens and their role in energy metabolism.  

PubMed

Iron plays a critical role in the physiology of Geobacter species. It serves as both an essential component for proteins and cofactors and an electron acceptor during anaerobic respiration. Here, we investigated the iron stimulon and ferric uptake regulator (Fur) regulon of Geobacter sulfurreducens to examine the coordination between uptake of Fe(II) and the reduction of Fe(III) at the transcriptional level. Gene expression studies across a variety of different iron concentrations in both the wild type and a ?fur mutant strain were used to determine the iron stimulon. The stimulon consists of a broad range of gene products, ranging from iron-utilizing to central metabolism and iron reduction proteins. Integration of gene expression and chromatin immunoprecipitation (ChIP) data sets assisted in the identification of the Fur transcriptional regulatory network and Fur's role as a regulator of the iron stimulon. Additional physiological and transcriptional analyses of G. sulfurreducens grown with various Fe(II) concentrations revealed the depth of Fur's involvement in energy metabolism and the existence of redundancy within the iron-regulatory network represented by IdeR, an alternative iron transcriptional regulator. These characteristics enable G. sulfurreducens to thrive in environments with fluctuating iron concentrations by providing it with a robust mechanism to maintain tight and deliberate control over intracellular iron homeostasis. PMID:24584254

Embree, Mallory; Qiu, Yu; Shieu, Wendy; Nagarajan, Harish; O'Neil, Regina; Lovley, Derek; Zengler, Karsten

2014-05-01

137

Extracting phosphoric iron under laboratorial conditions smelting bog iron ores  

NASA Astrophysics Data System (ADS)

In recent years it has been indicated by archaeometric investigations that phosphoric-iron (P-iron, low carbon steel with 0,5-1,5wt% P), which is an unknown and unused kind of steel in the modern industry, was widely used in different parts of the world in medieval times. In this study we try to explore the role of phosphorus in the arhaeometallurgy of iron and answer some questions regarding the smelting bog iron ores with high P-content. XRF analyses were performed on bog iron ores collected in Somogy county. Smelting experiments were carried out on bog iron ores using a laboratory model built on the basis of previously conducted reconstructed smelting experiments in copies of excavated furnaces. The effect of technological parameters on P-content of the resulted iron bloom was studied. OM and SEM-EDS analyses were carried out on the extracted iron and slag samples. On the basis of the material analyses it can be stated that P-iron is usually extracted but the P-content is highly affected by technological parameters. Typical microstructures of P-iron and of slag could also be identified. It could also be established that arsenic usually solved in high content in iron as well.

Török, B.; Thiele, A.

2013-12-01

138

Culture's Unacknowledged Iron Grip  

ERIC Educational Resources Information Center

Ideally, education provides mutual enrichment for professor and students. In this article, the author often fears that he is learning far more than his students are in a course on intercultural communication. Its real subject sometimes seems to be the iron grip of American culture upon his students. What is most fascinating is that the power of…

Engle, John

2007-01-01

139

Iron dominated magnets  

SciTech Connect

These two lectures on iron dominated magnets are meant for the student of accelerator science and contain general treatments of the subjects design and construction. The material is arranged in the categories: General Concepts and Cost Considerations, Profile Configuration and Harmonics, Magnetic Measurements, a few examples of ''special magnets'' and Materials and Practices. Extensive literature is provided.

Fischer, G.E.

1985-07-01

140

The Iron Project  

NASA Technical Reports Server (NTRS)

Recent advances in theoretical atomic physics have enabled large-scale calculation of atomic parameters for a variety of atomic processes with high degree of precision. The development and application of these methods is the aim of the Iron Project. At present the primary focus is on collisional processes for all ions of iron, Fe I - FeXXVI, and other iron-peak elements; new work on radiative processes has also been initiated. Varied applications of the Iron Project work to X-ray astronomy are discussed, and more general applications to other spectral ranges are pointed out. The IP work forms the basis for more specialized projects such as the RmaX Project, and the work on photoionization/recombination, and aims to provide a comprehensive and self-consistent set of accurate collisional and radiative cross sections, and transition probabilities, within the framework of relativistic close coupling formulation using the Breit-Pauli R-Matrix method. An illustrative example is presented of how the IP data may be utilized in the formation of X-ray spectra of the K alpha complex at 6.7 keV from He-like Fe XXV.

Pradhan, Anil K.

2000-01-01

141

The Ironic Curtain  

E-print Network

of the guard is accomplished with pomp and ceremony. The fact that there is little or no traffic to speak of in Pyongyang does not interfere with the gravity with which the traffic ladies carry out their work. Remember the iron curtain? Well, this must...

Hacker, Randi

2008-06-11

142

Company Name: General Dynamics Bath Iron Works Web Site: https://www.gdbiw.com  

E-print Network

Business, and Logistics, Supply Chain, Management System Integration Planning, Non-Destructive Technical/Manufacturing Brief Company Overview: Part of General Dynamics Marine Systems, Bath Iron Works is a full service

New Hampshire, University of

143

Iron status in the elderly  

PubMed Central

Iron deficiency anaemia is prevalent in older age, particularly after the age of 80. Serum ferritin concentrations also decline, although there is no evidence to suggest that changes in iron stores are an inevitable consequence of ageing. Chronic inflammation is a common condition in older people, making the measurement of iron status difficult, and it is likely that elevated levels of circulating hepcidin are responsible for changes in iron metabolism that result in systemic iron depletion. Other contributory factors are poor diet and some medications, such as aspirin. Anaemia in older age has undesirable health outcomes, including increased susceptibility to falling and depression. However, there are concerns about possible adverse effects of iron supplements, either in relation to pro-inflammatory effects in the gut or inappropriate tissue iron deposition. Brain iron levels are increased with age-related degenerative diseases, but it is not known if this is the cause or a consequence of the disease, and genetic factors are likely to play a role. In order to maintain body iron within the normal range a personalised approach is required, taking into account all of the factors that may affect iron metabolism and the available strategies for preventing iron deficiency or overload. PMID:24275120

Fairweather-Tait, Susan J.; Wawer, Anna A.; Gillings, Rachel; Jennings, Amy; Myint, Phyo K.

2014-01-01

144

Iron status in the elderly.  

PubMed

Iron deficiency anaemia is prevalent in older age, particularly after the age of 80. Serum ferritin concentrations also decline, although there is no evidence to suggest that changes in iron stores are an inevitable consequence of ageing. Chronic inflammation is a common condition in older people, making the measurement of iron status difficult, and it is likely that elevated levels of circulating hepcidin are responsible for changes in iron metabolism that result in systemic iron depletion. Other contributory factors are poor diet and some medications, such as aspirin. Anaemia in older age has undesirable health outcomes, including increased susceptibility to falling and depression. However, there are concerns about possible adverse effects of iron supplements, either in relation to pro-inflammatory effects in the gut or inappropriate tissue iron deposition. Brain iron levels are increased with age-related degenerative diseases, but it is not known if this is the cause or a consequence of the disease, and genetic factors are likely to play a role. In order to maintain body iron within the normal range a personalised approach is required, taking into account all of the factors that may affect iron metabolism and the available strategies for preventing iron deficiency or overload. PMID:24275120

Fairweather-Tait, Susan J; Wawer, Anna A; Gillings, Rachel; Jennings, Amy; Myint, Phyo K

2014-01-01

145

Combustion Iron Distribution and Deposition  

NASA Astrophysics Data System (ADS)

Iron is hypothesized to be an important micronutrient for ocean biota, thus modulating carbon dioxide uptake by the ocean biological pump. Studies have assumed that atmospheric deposition of iron to the open ocean is predominantly from mineral aerosols. For the first time, we model the source, transport and deposition of iron from combustion sources. Iron is produced in small quantities during fossil fuel burning, incinerator use, and biomass burning. The sources of combustion iron are concentrated in the industrialized regions and biomass burning regions, largely in the tropics. Model results suggest that combustion iron can represent up to 50 percent of the total iron deposited, but over open ocean regions is usually less than 5 percent of the total iron, with the highest values (less than 30 percent) close to the East Asian continent in the North Pacific. For ocean biogeochemistry the bioavailability of the iron is important, and this is often estimated by the fraction which is soluble (Fe(II)). Previous studies have argued that atmospheric processing of the relatively insoluble Fe(III) occurs to make it more soluble (Fe(II)). Modeled estimates of soluble iron amounts based solely on atmospheric processing as simulated here cannot match the variability in daily averaged in situ concentration measurements in Korea, which is located close to both combustion and dust sources. The best match to the observations is that there is substantial direct emissions of soluble iron from combustion processes. If we assume observed soluble Fe/black carbon (BC) ratios in Korea are representative of the whole globe, we obtain the result that deposition of soluble iron from combustion contribute 20-100 percent of the soluble iron deposition over many ocean regions. This implies that more work should be done refining the emissions and deposition of combustion sources of soluble iron globally.

Luo, C.; Mahowald, N.; Bond, T.; Chuang, P.; Artaxo, P.; Siefert, R.; Chen, Y.; Schauer, J.

2007-05-01

146

Combustion iron distribution and deposition  

NASA Astrophysics Data System (ADS)

Iron is hypothesized to be an important micronutrient for ocean biota, thus modulating carbon dioxide uptake by the ocean biological pump. Studies have assumed that atmospheric deposition of iron to the open ocean is predominantly from mineral aerosols. For the first time we model the source, transport, and deposition of iron from combustion sources. Iron is produced in small quantities during fossil fuel burning, incinerator use, and biomass burning. The sources of combustion iron are concentrated in the industrialized regions and biomass burning regions, largely in the tropics. Model results suggest that combustion iron can represent up to 50% of the total iron deposited, but over open ocean regions it is usually less than 5% of the total iron, with the highest values (<30%) close to the East Asian continent in the North Pacific. For ocean biogeochemistry the bioavailability of the iron is important, and this is often estimated by the fraction which is soluble (Fe(II)). Previous studies have argued that atmospheric processing of the relatively insoluble Fe(III) occurs to make it more soluble (Fe(II)). Modeled estimates of soluble iron amounts based solely on atmospheric processing as simulated here cannot match the variability in daily averaged in situ concentration measurements in Korea, which is located close to both combustion and dust sources. The best match to the observations is that there are substantial direct emissions of soluble iron from combustion processes. If we assume observed soluble Fe/black carbon ratios in Korea are representative of the whole globe, we obtain the result that deposition of soluble iron from combustion contributes 20-100% of the soluble iron deposition over many ocean regions. This implies that more work should be done refining the emissions and deposition of combustion sources of soluble iron globally.

Luo, Chao; Mahowald, N.; Bond, T.; Chuang, P. Y.; Artaxo, P.; Siefert, R.; Chen, Y.; Schauer, J.

2008-03-01

147

Degradation of chlorofluorocarbons using granular iron and bimetallic irons.  

PubMed

Degradation of trichlorofluoromethane (CFC11) and 1,1,2-trichloro-1,2,2-trifluoroethane (CFC113) by granular iron and bimetallic (nickel- or palladium-enhanced) irons was studied in flow-through column tests. Both compounds were rapidly degraded, following pseudo-first-order kinetics with respect to the parent compounds. The average pseudo-first-order rate constants for CFC11 were similar among different materials, except for palladium-enhanced iron (PdFe), in which the rate of degradation was about two times faster than for the other materials. In the case of CFC113, the rate constants for bimetallic irons were about two to three times greater than for the regular iron material. The smaller than expected differences in degradation rate constants of chlorofluorocarbons (CFCs) between regular iron and bimetallic irons suggested little, if any, catalytic effect of the bimetallic materials in the initial degradation step. Subsequent degradation steps involved catalytic hydrogenation, however, playing a significant role in further degradation of reaction intermediates. The degradation intermediates and final products of CFC11 and CFC113 suggested that degradation proceeded through hydrogenolysis and ?/?-elimination in the presence of regular iron (Fe) and nickel-enhanced iron (NiFe). Even though there is only minor benefit in the use of bimetallic iron in terms of degradation kinetics of the parent CFCs, enhanced degradation rates of intermediates such as chlorotriflouroethene (CTFE) in subsequent reaction steps could be beneficial. PMID:24492233

Jeen, Sung-Wook; Lazar, Snezana; Gui, Lai; Gillham, Robert W

2014-03-01

148

Degradation of chlorofluorocarbons using granular iron and bimetallic irons  

NASA Astrophysics Data System (ADS)

Degradation of trichlorofluoromethane (CFC11) and 1,1,2-trichloro-1,2,2-trifluoroethane (CFC113) by granular iron and bimetallic (nickel- or palladium-enhanced) irons was studied in flow-through column tests. Both compounds were rapidly degraded, following pseudo-first-order kinetics with respect to the parent compounds. The average pseudo-first-order rate constants for CFC11 were similar among different materials, except for palladium-enhanced iron (PdFe), in which the rate of degradation was about two times faster than for the other materials. In the case of CFC113, the rate constants for bimetallic irons were about two to three times greater than for the regular iron material. The smaller than expected differences in degradation rate constants of chlorofluorocarbons (CFCs) between regular iron and bimetallic irons suggested little, if any, catalytic effect of the bimetallic materials in the initial degradation step. Subsequent degradation steps involved catalytic hydrogenation, however, playing a significant role in further degradation of reaction intermediates. The degradation intermediates and final products of CFC11 and CFC113 suggested that degradation proceeded through hydrogenolysis and ?/?-elimination in the presence of regular iron (Fe) and nickel-enhanced iron (NiFe). Even though there is only minor benefit in the use of bimetallic iron in terms of degradation kinetics of the parent CFCs, enhanced degradation rates of intermediates such as chlorotriflouroethene (CTFE) in subsequent reaction steps could be beneficial.

Jeen, Sung-Wook; Lazar, Snezana; Gui, Lai; Gillham, Robert W.

2014-03-01

149

Failure analysis of a crankshaft made from ductile cast iron  

Microsoft Academic Search

This paper describes the failure analysis of a diesel engine crankshaft used in a truck, which is made from ductile cast iron. The crankshaft was found to break into two pieces at the crankpin portion before completion of warranty period. The crankshaft was induction hardened. An evaluation of the failed crankshaft was undertaken to assess its integrity that included a

Osman Asi

2006-01-01

150

Iron metabolism in aerobes: managing ferric iron hydrolysis and ferrous iron autoxidation  

PubMed Central

Aerobes and anaerobes alike express a plethora of essential iron enzymes; in the resting state, the iron atom(s) in these proteins are in the ferrous state. For aerobes, ferric iron is the predominant environmental valence form which, given ferric iron’s aqueous chemistry, occurs as ‘rust’, insoluble, bio-inert polymeric ferric oxide that results from the hydrolysis of [Fe(H2O)6]3+. Mobilizing this iron requires bio-ferrireduction which in turn requires managing the rapid autoxidation of the resulting FeII which occurs at pH > 6. This review examines the aqueous redox chemistry of iron and the mechanisms evolved in aerobes to suppress the ‘rusting out’ of FeIII and the ROS-generating autoxidation of FeII so as to make this metal ion available as the most ubiquitous prosthetic group in metallobiology. PMID:23264695

Kosman, Daniel J.

2012-01-01

151

Iron homeostasis and eye disease  

PubMed Central

Summary Iron is necessary for life, but excess iron can be toxic to tissues. Iron is thought to damage tissues primarily by generating oxygen free radicals through the Fenton reaction. We present an overview of the evidence supporting iron's potential contribution to a broad range of eye disease using an anatomical approach. Firstly, iron can be visualized in the cornea as iron lines in the normal aging cornea as well as in diseases like keratoconus and pterygium. In the lens, we present the evidence for the role of oxidative damage in cataractogenesis. Also, we review the evidence that iron may play a role in the pathogenesis of the retinal disease age-related macular degeneration. Although currently there is no direct link between excess iron and development of optic neuropathies, ferrous iron's ability to form highly reactive oxygen species may play a role in optic nerve pathology. Lastly, we discuss recent advances in prevention and therapeutics for eye disease with antioxidants and iron chelators,. PMID:19059309

Loh, Allison; Hadziahmetovic, Majda; Dunaief, Joshua L.

2009-01-01

152

Flare Plasma Iron Abundance  

NASA Technical Reports Server (NTRS)

The equivalent width of the iron-line complex at 6.7 keV seen in flare X-ray spectra suggests that the iron abundance of the hottest plasma at temperatures >approx.10 MK may sometimes be significantly lower than the nominal coronal abundance of four times the photospheric value that is commonly assumed. This conclusion is based on X-ray spectral observations of several flares seen in common with the Ramaty High Energy Solar Spectroscopic Imager (RHESSI) and the Solar X-ray Spectrometer (SOXS) on the second Indian geostationary satellite, GSAT-2. The implications of this will be discussed as it relates to the origin of the hot flare plasma - either plasma already in the corona that is directly heated during the flare energy release process or chromospheric plasma that is heated by flare-accelerated particles and driven up into the corona. Other possible explanations of lower-than-expected equivalent widths of the iron-line complex will also be discussed.

Dennis, Brian R.; Dan, Chau; Jain, Rajmal; Schwartz, Richard A.; Tolbert, Anne K.

2008-01-01

153

Molecular basis of inherited microcytic anemia due to defects in iron acquisition or heme synthesis  

PubMed Central

Microcytic anemia is the most commonly encountered anemia in general medical practice. Nutritional iron deficiency and ? thalassemia trait are the primary causes in pediatrics, whereas bleeding disorders and anemia of chronic disease are common in adulthood. Microcytic hypochromic anemia can result from a defect in globin genes, in heme synthesis, in iron availability or in iron acquisition by the erythroid precursors. These microcytic anemia can be sideroblastic or not, a trait which reflects the implications of different gene abnormalities. Iron is a trace element that may act as a redox component and therefore is integral to vital biological processes that require the transfer of electrons as in oxygen transport, oxidative phosphorylation, DNA biosynthesis and xenobiotic metabolism. However, it can also be pro-oxidant and to avoid its toxicity, iron metabolism is strictly controlled and failure of these control systems could induce iron overload or iron deficient anemia. During the past few years, several new discoveries mostly arising from human patients or mouse models have highlighted the implication of iron metabolism components in hereditary microcytic anemia, from intestinal absorption to its final inclusion into heme. In this paper we will review the new information available on the iron acquisition pathway by developing erythrocytes and its regulation, and we will consider only inherited microcytosis due to heme synthesis or to iron metabolism defects. This information could be useful in the diagnosis and classification of these microcytic anemias. PMID:19181781

Iolascon, Achille; De Falco, Luigia; Beaumont, Carole

2009-01-01

154

A novel model for brain iron uptake: introducing the concept of regulation.  

PubMed

Neurologic disorders such as Alzheimer's, Parkinson's disease, and Restless Legs Syndrome involve a loss of brain iron homeostasis. Moreover, iron deficiency is the most prevalent nutritional concern worldwide with many associated cognitive and neural ramifications. Therefore, understanding the mechanisms by which iron enters the brain and how those processes are regulated addresses significant global health issues. The existing paradigm assumes that the endothelial cells (ECs) forming the blood-brain barrier (BBB) serve as a simple conduit for transport of transferrin-bound iron. This concept is a significant oversimplification, at minimum failing to account for the iron needs of the ECs. Using an in vivo model of brain iron deficiency, the Belgrade rat, we show the distribution of transferrin receptors in brain microvasculature is altered in luminal, intracellular, and abluminal membranes dependent on brain iron status. We used a cell culture model of the BBB to show the presence of factors that influence iron release in non-human primate cerebrospinal fluid and conditioned media from astrocytes; specifically apo-transferrin and hepcidin were found to increase and decrease iron release, respectively. These data have been integrated into an interactive model where BBB ECs are central in the regulation of cerebral iron metabolism. PMID:25315861

Simpson, Ian A; Ponnuru, Padmavathi; Klinger, Marianne E; Myers, Roland L; Devraj, Kavi; Coe, Christopher L; Lubach, Gabriele R; Carruthers, Anthony; Connor, James R

2015-01-01

155

Ferric iron reduction by sulfur- and iron-oxidizing bacteria.  

PubMed Central

Acidophilic bacteria of the genera Thiobacillus and Sulfolobus are able to reduce ferric iron when growing on elemental sulfur as an energy source. It has been previously thought that ferric iron serves as a nonbiological oxidant in the formation of acid mine drainage and in the leaching of ores, but these results suggest that bacterial catalysis may play a significant role in the reactivity of ferric iron. PMID:825043

Brock, T D; Gustafson, J

1976-01-01

156

49 CFR 192.489 - Remedial measures: Cast iron and ductile iron pipelines.  

Code of Federal Regulations, 2011 CFR

... 2011-10-01 false Remedial measures: Cast iron and ductile iron pipelines. 192.489 Section 192.489 Transportation...Corrosion Control § 192.489 Remedial measures: Cast iron and ductile iron pipelines. (a) General...

2011-10-01

157

49 CFR 192.489 - Remedial measures: Cast iron and ductile iron pipelines.  

Code of Federal Regulations, 2012 CFR

... 2012-10-01 false Remedial measures: Cast iron and ductile iron pipelines. 192.489 Section 192.489 Transportation...Corrosion Control § 192.489 Remedial measures: Cast iron and ductile iron pipelines. (a) General...

2012-10-01

158

Iron isotopes constrain biologic and abiologic processes in banded iron formation genesis  

E-print Network

Iron isotopes constrain biologic and abiologic processes in banded iron formation genesis Clark M banded iron formations (BIFs) from the Hamersley Basin (Australia) and Transvaal Craton (South Africa, (2) complete reduction by bacterial dissimilatory iron reduction (DIR), and (3) interaction

Roden, Eric E.

159

46 CFR 148.275 - Iron oxide, spent; iron sponge, spent.  

Code of Federal Regulations, 2011 CFR

...Shipping 5 2011-10-01 2011-10-01 false Iron oxide, spent; iron sponge, spent. 148.275 Section 148.275 ...Special Requirements for Certain Materials § 148.275 Iron oxide, spent; iron sponge, spent. (a)...

2011-10-01

160

46 CFR 148.275 - Iron oxide, spent; iron sponge, spent.  

Code of Federal Regulations, 2013 CFR

...Shipping 5 2013-10-01 2013-10-01 false Iron oxide, spent; iron sponge, spent. 148.275 Section 148.275 ...Special Requirements for Certain Materials § 148.275 Iron oxide, spent; iron sponge, spent. (a)...

2013-10-01

161

49 CFR 192.489 - Remedial measures: Cast iron and ductile iron pipelines.  

Code of Federal Regulations, 2010 CFR

... 2010-10-01 false Remedial measures: Cast iron and ductile iron pipelines. 192.489 Section 192.489 Transportation...Corrosion Control § 192.489 Remedial measures: Cast iron and ductile iron pipelines. (a) General...

2010-10-01

162

46 CFR 148.275 - Iron oxide, spent; iron sponge, spent.  

Code of Federal Regulations, 2012 CFR

...Shipping 5 2012-10-01 2012-10-01 false Iron oxide, spent; iron sponge, spent. 148.275 Section 148.275 ...Special Requirements for Certain Materials § 148.275 Iron oxide, spent; iron sponge, spent. (a)...

2012-10-01

163

46 CFR 148.275 - Iron oxide, spent; iron sponge, spent.  

...Shipping 5 2014-10-01 2014-10-01 false Iron oxide, spent; iron sponge, spent. 148.275 Section 148.275 ...Special Requirements for Certain Materials § 148.275 Iron oxide, spent; iron sponge, spent. (a)...

2014-10-01

164

49 CFR 192.489 - Remedial measures: Cast iron and ductile iron pipelines.  

Code of Federal Regulations, 2013 CFR

... 2013-10-01 false Remedial measures: Cast iron and ductile iron pipelines. 192.489 Section 192.489 Transportation...Corrosion Control § 192.489 Remedial measures: Cast iron and ductile iron pipelines. (a) General...

2013-10-01

165

Intestinal Iron Homeostasis and Colon Tumorigenesis  

PubMed Central

Colorectal cancer (CRC) is the third most common cause of cancer-related deaths in industrialized countries. Understanding the mechanisms of growth and progression of CRC is essential to improve treatment. Iron is an essential nutrient for cell growth. Iron overload caused by hereditary mutations or excess dietary iron uptake has been identified as a risk factor for CRC. Intestinal iron is tightly controlled by iron transporters that are responsible for iron uptake, distribution, and export. Dysregulation of intestinal iron transporters are observed in CRC and lead to iron accumulation in tumors. Intratumoral iron results in oxidative stress, lipid peroxidation, protein modification and DNA damage with consequent promotion of oncogene activation. In addition, excess iron in intestinal tumors may lead to increase in tumor-elicited inflammation and tumor growth. Limiting intratumoral iron through specifically chelating excess intestinal iron or modulating activities of iron transporter may be an attractive therapeutic target for CRC. PMID:23812305

Xue, Xiang; Shah, Yatrik M.

2013-01-01

166

Iron and ferritin accumulate in separate cellular locations in Phaseolus seeds  

PubMed Central

Background Iron is an important micronutrient for all living organisms. Almost 25% of the world population is affected by iron deficiency, a leading cause of anemia. In plants, iron deficiency leads to chlorosis and reduced yield. Both animals and plants may suffer from iron deficiency when their diet or environment lacks bioavailable iron. A sustainable way to reduce iron malnutrition in humans is to develop staple crops with increased content of bioavailable iron. Knowledge of where and how iron accumulates in seeds of crop plants will increase the understanding of plant iron metabolism and will assist in the production of staples with increased bioavailable iron. Results Here we reveal the distribution of iron in seeds of three Phaseolus species including thirteen genotypes of P. vulgaris, P. coccineus, and P. lunatus. We showed that high concentrations of iron accumulate in cells surrounding the provascular tissue of P. vulgaris and P. coccineus seeds. Using the Perls' Prussian blue method, we were able to detect iron in the cytoplasm of epidermal cells, cells near the epidermis, and cells surrounding the provascular tissue. In contrast, the protein ferritin that has been suggested as the major iron storage protein in legumes was only detected in the amyloplasts of the seed embryo. Using the non-destructive micro-PIXE (Particle Induced X-ray Emission) technique we show that the tissue in the proximity of the provascular bundles holds up to 500 ?g g-1 of iron, depending on the genotype. In contrast to P. vulgaris and P. coccineus, we did not observe iron accumulation in the cells surrounding the provascular tissues of P. lunatus cotyledons. A novel iron-rich genotype, NUA35, with a high concentration of iron both in the seed coat and cotyledons was bred from a cross between an Andean and a Mesoamerican genotype. Conclusions The presented results emphasize the importance of complementing research in model organisms with analysis in crop plants and they suggest that iron distribution criteria should be integrated into selection strategies for bean biofortification. PMID:20149228

2010-01-01

167

Expanding horizons in iron chelation and the treatment of cancer: role of iron in the regulation of ER stress and the epithelial-mesenchymal transition.  

PubMed

Cancer is a major public health issue and, despite recent advances, effective clinical management remains elusive due to intra-tumoural heterogeneity and therapeutic resistance. Iron is a trace element integral to a multitude of metabolic processes, including DNA synthesis and energy transduction. Due to their generally heightened proliferative potential, cancer cells have a greater metabolic demand for iron than normal cells. As such, iron metabolism represents an important "Achilles' heel" for cancer that can be targeted by ligands that bind and sequester intracellular iron. Indeed, novel thiosemicarbazone chelators that act by a "double punch" mechanism to both bind intracellular iron and promote redox cycling reactions demonstrate marked potency and selectivity in vitro and in vivo against a range of tumours. The general mechanisms by which iron chelators selectively target tumour cells through the sequestration of intracellular iron fall into the following categories: (1) inhibition of cellular iron uptake/promotion of iron mobilisation; (2) inhibition of ribonucleotide reductase, the rate-limiting, iron-containing enzyme for DNA synthesis; (3) induction of cell cycle arrest; (4) promotion of localised and cytotoxic reactive oxygen species production by copper and iron complexes of thiosemicarbazones (e.g., Triapine(®) and Dp44mT); and (5) induction of metastasis and tumour suppressors (e.g., NDRG1 and p53, respectively). Emerging evidence indicates that chelators can further undermine the cancer phenotype via inhibiting the epithelial-mesenchymal transition that is critical for metastasis and by modulating ER stress. This review explores the "expanding horizons" for iron chelators in selectively targeting cancer cells. PMID:24472573

Lane, Darius J R; Mills, Thomas M; Shafie, Nurul H; Merlot, Angelica M; Saleh Moussa, Rayan; Kalinowski, Danuta S; Kovacevic, Zaklina; Richardson, Des R

2014-04-01

168

Pagophagia in iron deficiency anemia.  

PubMed

The relationship between pagophagia (ice pica) and iron deficiency anemia was studied. All 81 patients with iron deficiency anemia defined as hemoglobin <12.0 g/dl and ferritin level <12 ng/ml were interviewed about their habits of eating ice or other non-food substances. Pagophagia was defined as compulsive and repeated ingestion of at least one tray of ice or ice eating which was relieved after iron administration. Pagophagia was present in 13 patients (16.0%). All patients who received oral iron were periodically assessed employing a questionnaire on pagophagia and laboratory data. Iron therapy can cure the pagophagia earlier than hemoglobin recovery and repair of tissue iron deficiency. Although the pathogenesis of pagophagia is unclear, a biochemical approach involving the central nervous system might elucidate the mechanism underlying these abnormal behaviors. PMID:24850454

Uchida, Tatsumi; Kawati, Yasunori

2014-04-01

169

Microbial reduction of iron ore  

DOEpatents

A process is provided for reducing iron ore by treatment with microorganisms which comprises forming an aqueous mixture of iron ore, microorganisms operable for reducing the ferric iron of the iron ore to ferrous iron, and a substrate operable as an energy source for the microbial reduction; and maintaining the aqueous mixture for a period of time and under conditions operable to effect the reduction of the ore. Preferably the microorganism is Pseudomonas sp. 200 and the reduction conducted anaerobically with a domestic wastewater as the substrate. An aqueous solution containing soluble ferrous iron can be separated from the reacted mixture, treated with a base to precipitate ferrous hydroxide which can then be recovered as a concentrated slurry. 11 figs.

Hoffmann, M.R.; Arnold, R.G.; Stephanopoulos, G.

1989-11-14

170

Microbial reduction of iron ore  

DOEpatents

A process is provided for reducing iron ore by treatment with microorganisms which comprises forming an aqueous mixture of iron ore, microorganisms operable for reducing the ferric iron of the iron ore to ferrous iron, and a substrate operable as an energy source for the microbial reduction; and maintaining the aqueous mixture for a period of time and under conditions operable to effect the reduction of the ore. Preferably the microorganism is Pseudomonas sp. 200 and the reduction conducted anaerobically with a domestic wastewater as the substrate. An aqueous solution containing soluble ferrous iron can be separated from the reacted mixture, treated with a base to precipitate ferrous hydroxide which can then be recovered as a concentrated slurry.

Hoffmann, Michael R. (Pasadena, CA); Arnold, Robert G. (Pasadena, CA); Stephanopoulos, Gregory (Pasadena, CA)

1989-01-01

171

Intravenous Iron Sucrose and Oral Iron for the Treatment of Iron Deficiency Anaemia in Pregnancy  

PubMed Central

Purpose: The aim of this study was to compare the efficacy and safety of intravenous iron sucrose and oral iron administration for the treatment of iron deficiency anaemia in pregnancy. Materials and Methods: Hundred women with gestational age between 30 and 34 weeks with established iron deficiency anaemia with Haemoglobin-6-8g/dL were randomised to receive either oral ferrous sulphate 200 mg thrice daily or required dose of intravenous iron sucrose 200 mg in 200 ml NS on alternate days. Haemoglobin, haematocrit, mean corpuscular volume, reticulocyte count were measured at recruitment and on 2nd week, 4th week and at 37 weeks. Adverse drug reactions were also noted in both the groups. Results were analyzed by student’s t-test and Chi-square test. Results: Haemoglobin values varied significantly with time between the two groups at second week, 4th week and at term (p<0.005). The mean difference in mean corpuscular volume from the recruitment value was not significant at 2nd week. When compared to iron sucrose group, oral iron group had significant gastro-intestinal adverse effects. Conclusion: Intravenous iron sucrose treated iron deficiency anaemia of pregnancy faster, and more effectively than oral iron therapy, with no serious adverse drug reactions. PMID:24995217

Abhilashini, G.D.; Reddi, Rani

2014-01-01

172

Iron Aluminide Hot Gas Filters  

SciTech Connect

Currently, high temperature filter systems are in the demonstration phase with the first commercial scale hot filter systems being installed on integrated gasification combined cycle (IGCC) and pressurized fluid bed combustion cycle (PBFC) systems (70 MW). They are dependent on the development of durable and economic high temperature filter systems. These filters are mostly ceramic tubes or candles. Ceramic filter durability has not been high. Failure is usually attributed to mechanical or thermal shock: they can also undergo significant changes due to service conditions. The overall objective of this project is to commercialize weldable, crack resistant filters which will provide several years service in advanced power processes. The specific objectives of this project are to develop corrosion resistant alloys and manufacturing processes to make Iron Aluminide filter media, and to use a ``short term`` exposure apparatus supported by other tests to identify the most promising candidate (alloy plus sintering cycle). The objectives of the next phases are to demonstrate long term corrosion stability for the best candidate followed by the production of fifty filters (optional).

Hurley, J.; Brosious, S.; Johnson, M. [Pall Process Equipment Development Div., Pall Corp., Cortland, NY (United States)

1996-12-31

173

Preventing childhood anemia in India: iron supplementation and beyond.  

PubMed

Childhood anemia has major adverse consequences for health and development. It's prevalence in India continues to range from 70 to 90%. Although anemia is multifactorial in etiology, preventative efforts have predominantly focused on increasing iron intake, primarily through supplementation in pregnant and lactating women. Policy thrust for childhood anemia is only recent. However, program implementation is dismal; only 3.8-4.7% of preschoolers receive iron-folate supplements. There is an urgent need for effective governance and implementation. Policy makers must distinguish anemia from iron deficiency, and introduce additional area-specific interventions as an integrated package.Increased iron intake may yield maximum benefit but will only address up to half the burden. In 6-59 months old children, instead of 100 days' continuous dosing with iron-folate syrup in a year, a directly supervised intermittent supplementation (biweekly; ~100 days per year) merits consideration. Multiple micronutrient powders for home fortification of foods in 6-23 months old infants do not appear viable. Additional interventions include delayed cord clamping, earlier supplementation in low birth weight infants, appropriate infant and young child feeding guidelines, and intermittent supervised supplementation in children and adolescents through school health programs. Use of double (iron-folate)-fortified salt in mid-day meal programs deserves piloting.Important area-specific, non-iron interventions include targeted deworming, and prevention and treatment of hemoglobinopathies, malaria and other common infections. Routine addition of multi-micronutrients to iron-folate supplementation appears unjustified currently. There is a pressing need to conduct relevant research, especially to inform etiology, additional interventions and implementation issues. PMID:23388662

Sachdev, H P S; Gera, T

2013-05-01

174

Four new iron meteorite finds  

NASA Technical Reports Server (NTRS)

Four new iron meteorites are described: Buenaventura (IIIB) from Chihuahua, Mexico: mass 114 kg; Denver City (anomalous) from Texas, USA: mass 26.1 kg; Kinsella (IIIB) from Alberta, Canada: mass 3.7 kg; and Tacoma (IA) from Washington, USA: mass 17 g. Denver City is unique - i.e., not related to any other known iron. Tacoma is the smallest iron meteorite recorded. The meteorites were initially discovered in 1969, 1975, 1946, and between 1925 and 1932, respectively.

Scott, E. R. D.; Wasson, J. T.; Bild, R. W.

1977-01-01

175

Magnetostructural study of iron sucrose  

NASA Astrophysics Data System (ADS)

Magnetic and structural analyses have been performed on an iron sucrose complex used as a haematinic agent. The system contains two-line ferrihydrite particles of about 5 nm that are superparamagnetic above approximately 50 K. The observed low-temperature magnetic dynamics of this compound is closer to simple models than in the case of other iron-containing drugs for intravenous use like iron dextran.

Gutiérrez, Lucía; del Puerto Morales, María; José Lázaro, Francisco

2005-05-01

176

46 CFR 56.60-10 - Cast iron and malleable iron.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Cast iron and malleable iron. 56.60-10...APPURTENANCES Materials § 56.60-10 Cast iron and malleable iron. (a) The low ductility of cast iron and malleable iron should be...

2010-10-01

177

46 CFR 56.60-10 - Cast iron and malleable iron.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Cast iron and malleable iron. 56.60-10...APPURTENANCES Materials § 56.60-10 Cast iron and malleable iron. (a) The low ductility of cast iron and malleable iron should be...

2011-10-01

178

46 CFR 56.60-10 - Cast iron and malleable iron.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Cast iron and malleable iron. 56.60-10...APPURTENANCES Materials § 56.60-10 Cast iron and malleable iron. (a) The low ductility of cast iron and malleable iron should be...

2013-10-01

179

46 CFR 56.60-10 - Cast iron and malleable iron.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Cast iron and malleable iron. 56.60-10...APPURTENANCES Materials § 56.60-10 Cast iron and malleable iron. (a) The low ductility of cast iron and malleable iron should be...

2012-10-01

180

Labile iron in parenteral iron formulations: a quantitative and comparative study  

Microsoft Academic Search

Background. Evidence of iron-mediated oxidative stress, neutrophil dysfunction and enhanced bacterial growth after intravenous (IV) iron administration has been ascribed to a labile or bioactive iron fraction present in all IV iron agents. Methods. To quantify and compare the size of the labile fraction in several classes of IV iron agents, we examined iron donation to transferrin (Tf) in vitro

David Van Wyck; Jaime Anderson; Kevin Johnson

181

Heavy meals: mechanisms of high affinity iron acquisition in iron-limited ecosystems  

E-print Network

#12;· Biological iron limitation high-affinity iron uptake systems · Siderophore controlled iron oxide reductive dissolution in the presence of siderophores · Iron isotope fractionation by siderophore controlledHeavy meals: mechanisms of high affinity iron acquisition in iron-limited ecosystems Stephan M

Einat, Aharonov

182

Snapshot of iron response in Shewanella oneidensis by gene network reconstruction  

PubMed Central

Background Iron homeostasis of Shewanella oneidensis, a ?-proteobacterium possessing high iron content, is regulated by a global transcription factor Fur. However, knowledge is incomplete about other biological pathways that respond to changes in iron concentration, as well as details of the responses. In this work, we integrate physiological, transcriptomics and genetic approaches to delineate the iron response of S. oneidensis. Results We show that the iron response in S. oneidensis is a rapid process. Temporal gene expression profiles were examined for iron depletion and repletion, and a gene co-expression network was reconstructed. Modules of iron acquisition systems, anaerobic energy metabolism and protein degradation were the most noteworthy in the gene network. Bioinformatics analyses suggested that genes in each of the modules might be regulated by DNA-binding proteins Fur, CRP and RpoH, respectively. Closer inspection of these modules revealed a transcriptional regulator (SO2426) involved in iron acquisition and ten transcriptional factors involved in anaerobic energy metabolism. Selected genes in the network were analyzed by genetic studies. Disruption of genes encoding a putative alcaligin biosynthesis protein (SO3032) and a gene previously implicated in protein degradation (SO2017) led to severe growth deficiency under iron depletion conditions. Disruption of a novel transcriptional factor (SO1415) caused deficiency in both anaerobic iron reduction and growth with thiosulfate or TMAO as an electronic acceptor, suggesting that SO1415 is required for specific branches of anaerobic energy metabolism pathways. Conclusion Using a reconstructed gene network, we identified major biological pathways that were differentially expressed during iron depletion and repletion. Genetic studies not only demonstrated the importance of iron acquisition and protein degradation for iron depletion, but also characterized a novel transcriptional factor (SO1415) with a role in anaerobic energy metabolism. PMID:19321007

Yang, Yunfeng; Harris, Daniel P; Luo, Feng; Xiong, Wenlu; Joachimiak, Marcin; Wu, Liyou; Dehal, Paramvir; Jacobsen, Janet; Yang, Zamin; Palumbo, Anthony V; Arkin, Adam P; Zhou, Jizhong

2009-01-01

183

Snapshot of iron response in Shewanella oneidensis by gene network reconstruction  

SciTech Connect

Background: Iron homeostasis of Shewanella oneidensis, a gamma-proteobacterium possessing high iron content, is regulated by a global transcription factor Fur. However, knowledge is incomplete about other biological pathways that respond to changes in iron concentration, as well as details of the responses. In this work, we integrate physiological, transcriptomics and genetic approaches to delineate the iron response of S. oneidensis. Results: We show that the iron response in S. oneidensis is a rapid process. Temporal gene expression profiles were examined for iron depletion and repletion, and a gene co-expression network was reconstructed. Modules of iron acquisition systems, anaerobic energy metabolism and protein degradation were the most noteworthy in the gene network. Bioinformatics analyses suggested that genes in each of the modules might be regulated by DNA-binding proteins Fur, CRP and RpoH, respectively. Closer inspection of these modules revealed a transcriptional regulator (SO2426) involved in iron acquisition and ten transcriptional factors involved in anaerobic energy metabolism. Selected genes in the network were analyzed by genetic studies. Disruption of genes encoding a putative alcaligin biosynthesis protein (SO3032) and a gene previously implicated in protein degradation (SO2017) led to severe growth deficiency under iron depletion conditions. Disruption of a novel transcriptional factor (SO1415) caused deficiency in both anaerobic iron reduction and growth with thiosulfate or TMAO as an electronic acceptor, suggesting that SO1415 is required for specific branches of anaerobic energy metabolism pathways. Conclusions: Using a reconstructed gene network, we identified major biological pathways that were differentially expressed during iron depletion and repletion. Genetic studies not only demonstrated the importance of iron acquisition and protein degradation for iron depletion, but also characterized a novel transcriptional factor (SO1415) with a role in anaerobic energy metabolism.

Yang, Yunfeng; Harris, Daniel P.; Luo, Feng; Xiong, Wenlu; Joachimiak, Marcin; Wu, Liyou; Dehal, Paramvir; Jacobsen, Janet; Yang, Zamin; Palumbo, Anthony V.; Arkin, Adam P.; Zhou, Jizhong

2008-10-09

184

Electrochemically fabricated zero-valent iron, iron-nickel, and iron-palladium nanowires for environmental remediation applications  

Microsoft Academic Search

Monodisperse crystalline zero-valent iron, iron-nickel, iron-palladium nanowires were synthesised using template-directed electrodeposition methods. Prior to nanowire fabrication, alumina nanotemplates with controlled pore structure (e.g. pore diameter and porosity) were fabricated by anodising high purity aluminium foil in sulphuric acid. After fabrication of alumina nanotemplates, iron, iron-nickel and iron- palladium nanowires were electrodeposited within the pore structure. The dimensions of nanowires

B.-Y. Yoo; S. C. Hernandez; B. Koo; Y. Rheem; N. V. Myung

2007-01-01

185

Iron Metabolism and Iron Chelation in Sickle Cell Disease  

Microsoft Academic Search

This review highlights recent advances in iron metabolism that are relevant to sickle cell disease (SCD). SCD is a common hemoglobinopathy that results in chronic inflammation. Improved understanding of how iron metabolism is controlled by proteins such as hepcidin, ferroportin, hypoxia-inducible factor 1, and growth differentiation factor 15 have revealed how they are involved in the organ toxicity of SCD.

Patrick B. Walter; Paul Harmatz; Elliott Vichinsky

2009-01-01

186

IRON RELEASE AND COLORED WATER FORMATION FROM IRON SCALES  

EPA Science Inventory

Iron corrosion in water distribution networks is of special concern in the drinking water industry because of the large amount of unlined iron pipe that is in use. Corrosion can destroy the pipe, consume oxidants and disinfectants in the water, create scales that increase the en...

187

Iron uptake and iron-repressible polypeptides in Yersinia pestis.  

PubMed

Pigmented (Pgm+) cells of Yersinia pestis are virulent, are sensitive to pesticin, adsorb exogenous hemin at 26 degrees C (Hms+), produce iron-repressible outer membrane proteins, and grow at 37 degrees C in iron-deficient media. These traits are lost upon spontaneous deletion of a chromosomal 102-kb pgm locus (Pgm-). Here we demonstrate that an Hms+ but pesticin-resistant (Pst(r)) mutant acquired a 5-bp deletion in the pesticin receptor gene (psn) encoding IrpB to IrpD. Growth and assimilation of iron by Pgm- and Hms+ Pst(r) mutants were markedly inhibited by ferrous chelators at 37 degrees C; inhibition by ferric and ferrous chelators was less effective at 26 degrees C. Iron-deficient growth at 26 degrees C induced iron-regulated outer membrane proteins of 34, 28.5, and 22.5 kDa and periplasmic polypeptides of 33.5 and 30 kDa. These findings provide a basis for understanding the psn-driven system of iron uptake, indicate the existence of at least one additional 26 degrees C-dependent iron assimilation system, and define over 30 iron-repressible proteins in Y. pestis. PMID:8757829

Lucier, T S; Fetherston, J D; Brubaker, R R; Perry, R D

1996-08-01

188

Iron uptake and iron-repressible polypeptides in Yersinia pestis.  

PubMed Central

Pigmented (Pgm+) cells of Yersinia pestis are virulent, are sensitive to pesticin, adsorb exogenous hemin at 26 degrees C (Hms+), produce iron-repressible outer membrane proteins, and grow at 37 degrees C in iron-deficient media. These traits are lost upon spontaneous deletion of a chromosomal 102-kb pgm locus (Pgm-). Here we demonstrate that an Hms+ but pesticin-resistant (Pst(r)) mutant acquired a 5-bp deletion in the pesticin receptor gene (psn) encoding IrpB to IrpD. Growth and assimilation of iron by Pgm- and Hms+ Pst(r) mutants were markedly inhibited by ferrous chelators at 37 degrees C; inhibition by ferric and ferrous chelators was less effective at 26 degrees C. Iron-deficient growth at 26 degrees C induced iron-regulated outer membrane proteins of 34, 28.5, and 22.5 kDa and periplasmic polypeptides of 33.5 and 30 kDa. These findings provide a basis for understanding the psn-driven system of iron uptake, indicate the existence of at least one additional 26 degrees C-dependent iron assimilation system, and define over 30 iron-repressible proteins in Y. pestis. PMID:8757829

Lucier, T S; Fetherston, J D; Brubaker, R R; Perry, R D

1996-01-01

189

IRON TEEMING FROM CUPOLA (UPPER RIGHT CORNER) DUCTILE IRON LADLE ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

IRON TEEMING FROM CUPOLA (UPPER RIGHT CORNER) DUCTILE IRON LADLE MOVING DOWN TRACK IN PREPARATION FOR DISTRIBUTION TO DE LAVAUD MACHINES. - United States Pipe & Foundry Company Plant, Melting & Treatment Areas, 2023 St. Louis Avenue at I-20/59, Bessemer, Jefferson County, AL

190

IRON TEEMING FROM CUPOLA (UPPER RIGHT CORNER) DUCTILE IRON LADLE ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

IRON TEEMING FROM CUPOLA (UPPER RIGHT CORNER) DUCTILE IRON LADLE MOVING DOWN TRACK IN PREPARATION FOR DISTRIBUTION TO DE LAVAUD MACHINES, LADLE TRANSFER CRANE ON FAR LEFT. - United States Pipe & Foundry Company Plant, Melting & Treatment Areas, 2023 St. Louis Avenue at I-20/59, Bessemer, Jefferson County, AL

191

The Iron Metallome in Eukaryotic Organisms  

PubMed Central

This chapter is focused on the iron metallome in eukaryotes at the cellular and subcellular level, including properties, utilization in metalloproteins, trafficking, storage, and regulation of these processes. Studies in the model eukaryote Saccharomyces cerevisiae and mammalian cells will be highlighted. The discussion of iron properties will center on the speciation and localization of intracellular iron as well as the cellular and molecular mechanisms for coping with both low iron bioavailability and iron toxicity. The section on iron metalloproteins will emphasize heme, iron-sulfur cluster, and non-heme iron centers, particularly their cellular roles and mechanisms of assembly. The section on iron uptake, trafficking, and storage will compare methods used by yeast and mammalian cells to import iron, how this iron is brought into various organelles, and types of iron storage proteins. Regulation of these processes will be compared between yeast and mammalian cells at the transcriptional, post-transcriptional, and post-translational levels. PMID:23595675

Dlouhy, Adrienne C.; Outten, Caryn E.

2013-01-01

192

21 CFR 522.1182 - Iron injection.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Iron injection. 522.1182 Section 522...FORM NEW ANIMAL DRUGS § 522.1182 Iron injection. (a) Specifications ...1) 100 milligrams (mg) of elemental iron derived from: (i) Ferric...

2013-04-01

193

21 CFR 522.1182 - Iron injection.  

...2014-04-01 2014-04-01 false Iron injection. 522.1182 Section 522...FORM NEW ANIMAL DRUGS § 522.1182 Iron injection. (a) Specifications. ...1) 100 milligrams (mg) of elemental iron derived from: (i) Ferric...

2014-04-01

194

21 CFR 73.3125 - Iron oxides.  

...2014-04-01 2014-04-01 false Iron oxides. 73.3125 Section 73.3125...CERTIFICATION Medical Devices § 73.3125 Iron oxides. (a) Identity and specifications. The color additive iron oxides (CAS Reg. No....

2014-04-01

195

21 CFR 522.1182 - Iron injection.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Iron injection. 522.1182 Section 522...FORM NEW ANIMAL DRUGS § 522.1182 Iron injection. (a) Specifications ...1) 100 milligrams (mg) of elemental iron derived from: (i) Ferric...

2012-04-01

196

49 CFR 230.91 - Chafing irons.  

Code of Federal Regulations, 2010 CFR

... 2010-10-01 2010-10-01 false Chafing irons. 230.91 Section 230.91 Transportation ...Draw Gear and Draft Systems § 230.91 Chafing irons. Chafing irons that permit proper curving shall be securely...

2010-10-01

197

21 CFR 522.1182 - Iron injection.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Iron injection. 522.1182 Section 522...FORM NEW ANIMAL DRUGS § 522.1182 Iron injection. (a) Specifications ...1) 100 milligrams (mg) of elemental iron derived from: (i) Ferric...

2011-04-01

198

21 CFR 73.3125 - Iron oxides.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Iron oxides. 73.3125 Section 73.3125...CERTIFICATION Medical Devices § 73.3125 Iron oxides. (a) Identity and specifications. The color additive iron oxides (CAS Reg. No....

2010-04-01

199

21 CFR 73.3125 - Iron oxides.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Iron oxides. 73.3125 Section 73.3125...CERTIFICATION Medical Devices § 73.3125 Iron oxides. (a) Identity and specifications. The color additive iron oxides (CAS Reg. No....

2011-04-01

200

49 CFR 230.91 - Chafing irons.  

Code of Federal Regulations, 2013 CFR

... 2013-10-01 2013-10-01 false Chafing irons. 230.91 Section 230.91 Transportation ...Draw Gear and Draft Systems § 230.91 Chafing irons. Chafing irons that permit proper curving shall be securely...

2013-10-01

201

21 CFR 73.3125 - Iron oxides.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Iron oxides. 73.3125 Section 73.3125...CERTIFICATION Medical Devices § 73.3125 Iron oxides. (a) Identity and specifications. The color additive iron oxides (CAS Reg. No....

2013-04-01

202

49 CFR 230.91 - Chafing irons.  

Code of Federal Regulations, 2012 CFR

... 2012-10-01 2012-10-01 false Chafing irons. 230.91 Section 230.91 Transportation ...Draw Gear and Draft Systems § 230.91 Chafing irons. Chafing irons that permit proper curving shall be securely...

2012-10-01

203

21 CFR 73.3125 - Iron oxides.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Iron oxides. 73.3125 Section 73.3125...CERTIFICATION Medical Devices § 73.3125 Iron oxides. (a) Identity and specifications. The color additive iron oxides (CAS Reg. No....

2012-04-01

204

49 CFR 230.91 - Chafing irons.  

Code of Federal Regulations, 2011 CFR

... 2011-10-01 2011-10-01 false Chafing irons. 230.91 Section 230.91 Transportation ...Draw Gear and Draft Systems § 230.91 Chafing irons. Chafing irons that permit proper curving shall be securely...

2011-10-01

205

Can Iron Lift Your Learning Ability?  

ERIC Educational Resources Information Center

Presents samples of publicly available materials related to the role of iron in the diet. Summarizes what nutritionists feel about iron in the human diet and suggests some experiments related to iron for the classroom. (AIM)

Schibeci, Renato

1997-01-01

206

Complementary Vibrational Spectroscopy Investigations of Iron and Iron-Bearing Minerals (Invited)  

NASA Astrophysics Data System (ADS)

The high-pressure elastic and thermodynamic properties of iron have been extensively studied because iron is thought to be the main constituent in Earth's core, along with ~5 to 10 wt% nickel and some light elements. In particular, nuclear resonant inelastic x-ray scattering (NRIXS) is an isotope-selective technique that has been used to investigate the vibrational properties of 57Fe at high-pressure via its measured phonon density of states (DOS) [e.g., 1]. For example, the low-energy region of a material's phonon DOS is proportional to its Debye sound velocity (vD), which reflects an average of its compressional (vP) and shear (vS) sound velocities, weighted more heavily towards vS [2]. In order to separate the compressional and shear components of vD, one often relies on established equations of state (EOS) which, in the case of iron, diverge above 100 GPa [e.g., 3; 4]. In turn, such uncertainties are propagated into iron's sound velocities--particularly vP--at pressures approaching those of Earth's core. Here we demonstrate how the combination of NRIXS and high-energy resolution inelastic x-ray scattering (HERIX) data allows for the determination of both vP and vS, independent of an EOS. In particular, we used NRIXS and HERIX to probe the total phonon DOS and points along the longitudinal acoustic phonon branch, respectively, of pure iron loaded into similarly prepared diamond anvil cells, up to a pressure of 171 GPa at 300 K [1; 5]. Experiments were performed at the Advanced Photon Source and European Synchrotron Radiation Facility, where sample volumes (densities) were also measured with in-situ x-ray diffraction. Using established NRIXS and HERIX fitting procedures, we determined iron's density-dependent vD and vP, respectively, accounting for mass effects in the former parameter using a harmonic oscillator model. The combination of these datasets [1; 5] provides a new tight constraint on the density-dependent compressional and shear sound velocities of iron, independent of an EOS. In light of these new findings, we will discuss specific implications for Earth's core, and give examples of additional systems to which such a combination of techniques can be applied. Finally, in the case of pure 57Fe, the total phonon DOS is measured by NRIXS, thus providing a wealth of information about its thermodynamic properties [2]. For example, iron's mean force constant can be obtained from its integrated phonon DOS, and is related to iron's equilibrium isotopic partition function ratios (?-factors). Therefore, we will present how high-pressure NRIXS experiments can provide information about the predicted distribution of iron isotopes during equilibrium processes involving solid iron in the deep Earth [1]. References: 1. Murphy, CA, Jackson, JM, and Sturhahn, W (2013), J. Geophys. Res. Solid Earth, 118, 1999-2016, doi:10.1002/jgrb.50166. 2. Sturhahn, W, and Jackson, JM (2007), GSA Special Paper 421, 157-174, doi:10.1130/2007.2421(09). 3. Mao, HK et al. (1990), J. Geophys. Res. Solid Earth, 95, 21737-21742, doi:10.1029/JB095iB13p21737. 4. Dewaele, A et al. (2006), Phys. Rev. Lett., 97, 215504, doi:10.1103/PhysRevLett.97.215504. 5. Antonangeli, D et al. (2012), Earth Planet. Sci. Lett., 331-332, 210-214, doi:10.1016/j.epsl.2012.03.024.

Murphy, C. A.; Antonangeli, D.; Fiquet, G.; Fei, Y.; Alatas, A.; Dera, P. K.

2013-12-01

207

Compacted graphite iron: Cast iron makes a comeback  

NASA Astrophysics Data System (ADS)

Although compacted graphite iron has been known for more than four decades, the absence of a reliable mass-production technique has resulted in relatively little effort to exploit its operational benefits. However, a proven on-line process control technology developed by SinterCast allows for series production of complex components in high-quality CGI. The improved mechanical properties of compacted graphite iron relative to conventional gray iron allow for substantial weight reduction in gasoline and diesel engines or substantial increases in horsepower, or an optimal combination of both. Concurrent with these primary benefits, CGI also provides significant emissions and fuel efficiency benefits allowing automakers to meet legislated performance standards. The operational and environmental benefits of compacted graphite iron together with its low cost and recyclability reinforce cast iron as a prime engineering material for the future.

Dawson, S.

1994-08-01

208

Iron in yeast: Mechanisms involved in homeostasis  

Microsoft Academic Search

Iron homeostasis results from matching iron uptake to cell growth and division in the context of the overall cell requirement\\u000a for iron. Fungi achieve this balance by transcriptional regulation of the genes that encode iron uptake activities; post-transcriptional\\u000a regulation of the synthesis of proteins that use iron; and storage and recycling of iron to meet short-term needs in times\\u000a of

Ernest Kwok; Daniel Kosman

209

Iron biofortification of maize grain  

Technology Transfer Automated Retrieval System (TEKTRAN)

Mineral nutrient deficiencies are a worldwide problem that is directly correlated with poverty and food insecurity. The most common of these is iron deficiency; more than one-third of the world’s population suffers from iron deficiency-induced anemia, 80% of which are in developing countries. The co...

210

Iron biofortification of maize grain  

Technology Transfer Automated Retrieval System (TEKTRAN)

Mineral nutrient deficiencies are a worldwide problem that is directly correlated with poverty and food insecurity. The most common of these is iron deficiency; more than one-third of the world’s population suffers from iron deficiency-induced anemia, 80% of which are in developing countries. The de...

211

Microencapsulated iron for milk fortification.  

PubMed

This study was designed to develop a microencapsulated iron that could be used to fortify milk and to determine the sensory properties of milk fortified with microencapsulated iron. Coating material was polyglycerol monostearate (PGMS), and selected core material was ferric ammonium sulfate. The highest efficiency of microencapsulation was 75% with 5:1:30 ratio (w/w/v) as coating to core materials to distilled water. Iron release was 12% when stored at 4 degrees C for 3 days. The TBA value was the lowest when 100 ppm of capsulated iron was added into milk and was significantly lower in capsulated groups compared with that in uncapsulated groups. In an in vitro study, only 3-5% of iron was released in simulated gastric fluid (pH 3, 4, 5, and 6). Comparatively, iron release increased dramatically from 12.3% (pH 5) to 95.7% (pH 8) for 60 min of incubation in simulated intestinal fluid. In a sensory analysis, most aspects except for metallic taste and color were not significantly different between control and capsulated iron fortified milk at 3 days of storage. However, between capsulated and uncapsulated groups, astringency, metallic, color, and overall scores were significantly different. The present study indicated that the use of microencapsulated iron with PGMS is effective for fortifying milk. PMID:14664543

Kwak, H S; Yang, K M; Ahn, J

2003-12-17

212

Iron around the clock.  

PubMed

Carbon assimilation, a key determinant of plant biomass production, is under circadian regulation. Light and temperature are major inputs of the plant clock that control various daily rhythms. Such rhythms confer adaptive advantages to the organisms by adjusting their metabolism in anticipation of environmental fluctuations. The relationship between the circadian clock and nutrition extends far beyond the regulation of carbon assimilation as mineral nutrition, and specially iron homeostasis, is regulated through this mechanism. Conversely, iron status was identified as a new and important input regulating the central oscillator, raising the question of the nature of the Fe-dependent signal that modulates the period of the circadian clock. Several lines of evidence strongly suggest that fully developed and functional chloroplasts as well as early light signalling events, involving phytochromes, are essential to couple the clock to Fe responses. Nevertheless, the exact nature of the signal, which most probably involves unknown or not yet fully characterized elements of the chloroplast-to-nucleus retrograde signalling pathway, remains to be identified. Finally, this regulation may also involves epigenetic components. PMID:24908512

Tissot, Nicolas; Przybyla-Toscano, Jonathan; Reyt, Guilhem; Castel, Baptiste; Duc, Céline; Boucherez, Jossia; Gaymard, Frédéric; Briat, Jean-François; Dubos, Christian

2014-07-01

213

Fluidized bed for removing iron and acidity from acid mine drainage  

SciTech Connect

Acid mine drainage (AMD) continues to be an important water pollution problem around the world. A fluidized bed reactor (FBR) for the removal of iron from acid mine drainage (AMD) was evaluated as part of a prototype multistage system, which included a bioreactor to oxidize ferrous iron, an FBR for the precipitation of ferric iron as a coating on media, and a carbonate bed (CB) for pH control. In the integrated system, a 99% iron removal efficiency was achieved, with effluent iron concentration remaining <3 mg L{sup {minus}1} and pH > 6. The optimum pH for iron removal in the FBR was about pH 3.5. Above that pH, and above an iron loading of about 0.20 mg Fe h{sup {minus}1} m{sup {minus}2} reactor surface area, suspended iron particles developed in the reactor system. Particulates in the feed had an adverse impact on the removal performance of the system. Schwertmannite appeared to be the predominant mineral formed in the precipitation reactor. Coating growth on the sand media appeared to result from the attachment and consolidation of small iron particles (<1.0 {mu}m) that formed in the bulk solution.

Diz, H.R.; Novak, J.T. [Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States). Dept. of Civil Engineering

1998-08-01

214

Blockage of mitochondrial calcium uniporter prevents iron accumulation in a model of experimental subarachnoid hemorrhage.  

PubMed

Previous studies have shown that iron accumulation is involved in the pathogenesis of brain injury following subarachnoid hemorrhage (SAH) and chelation of iron reduced mortality and oxidative DNA damage. We previously reported that blockage of mitochondrial calcium uniporter (MCU) provided benefit in the early brain injury after experimental SAH. This study was undertaken to identify whether blockage of MCU could ameliorate iron accumulation-associated brain injury following SAH. Therefore, we used two reagents ruthenium red (RR) and spermine (Sper) to inhibit MCU. Sprague-Dawley (SD) rats were randomly divided into four groups including sham, SAH, SAH+RR, and SAH+Sper. Biochemical analysis and histological assays were performed. The results confirmed the iron accumulation in temporal lobe after SAH. Interestingly, blockage of MCU dramatically reduced the iron accumulation in this area. The mechanism was revealed that inhibition of MCU reversed the down-regulation of iron regulatory protein (IRP) 1/2 and increase of ferritin. Iron-sulfur cluster dependent-aconitase activity was partially conserved when MCU was blocked. In consistence with this and previous report, ROS levels were notably reduced and ATP supply was rescued; levels of cleaved caspase-3 dropped; and integrity of neurons in temporal lobe was protected. Taken together, our results indicated that blockage of MCU could alleviate iron accumulation and the associated injury following SAH. These findings suggest that the alteration of calcium and iron homeostasis be coupled and MCU be considered to be a therapeutic target for patients suffering from SAH. PMID:25529443

Yan, Huiying; Hao, Shuangying; Sun, Xiaoyan; Zhang, Dingding; Gao, Xin; Yu, Zhuang; Li, Kuanyu; Hang, Chun-Hua

2015-01-24

215

Geophysical signatures of disseminated iron minerals: A proxy for understanding subsurface biophysicochemical processes  

NASA Astrophysics Data System (ADS)

studies have linked biogeophysical signatures to the presence of iron minerals resulting from distinct biophysicochemical processes. Utilizing geophysical methods as a proxy of such biophysicochemical processes requires an understanding of the geophysical signature of the different iron minerals. Laboratory experiments were conducted to investigate the complex conductivity and magnetic susceptibility signatures of five iron minerals disseminated in saturated porous media under variable iron mineral content and grain size. Both pyrite and magnetite show high quadrature and inphase conductivities compared to hematite, goethite, and siderite, whereas magnetite was the highly magnetic mineral dominating the magnetic susceptibility measurements. The quadrature conductivity spectra of both pyrite and magnetite exhibit a well-defined characteristic relaxation peak below 10 kHz, not observed with the other iron minerals. The quadrature conductivity and magnetic susceptibility of individual and a mixture of iron minerals are dominated and linearly proportional to the mass fraction of the highly conductive (pyrite and magnetite) and magnetic (magnetite) iron minerals, respectively. The quadrature conductivity magnitude increased with decreasing grain size diameter of magnetite and pyrite with a progressive shift of the characteristic relaxation peak toward higher frequencies. The quadrature conductivity response of a mixture of different grain sizes of iron minerals is shown to be additive, whereas magnetic susceptibility measurements were insensitive to the variation in grain size diameters (1-0.075 mm). The integration of complex conductivity and magnetic susceptibility measurements can therefore provide a complimentary tool for the successful investigation of in situ biophysicochemical processes resulting in biotransformation or secondary iron mineral precipitation.

Abdel Aal, Gamal Z.; Atekwana, Estella A.; Revil, A.

2014-09-01

216

Magnetic resonance assessment of iron overload by separate measurement of tissue ferritin and hemosiderin iron  

PubMed Central

With transfusional iron overload, almost all the excess iron is sequestered intracellularly as rapidly mobilizable, dispersed, soluble, ferritin iron, and as aggregated, insoluble hemosiderin iron for long-term storage. Established magnetic resonance imaging (MRI) indicators of tissue iron (R2, R2*) are principally influenced by hemosiderin iron and change slowly, even with intensive iron chelation. Intracellular ferritin iron is evidently in equilibrium with the low-molecular-weight cytosolic iron pool that can change rapidly with iron chelation. We have developed a new magnetic resonance imaging (MRI) method to separately measure ferritin and hemosiderin iron, based on the non-monoexponential signal decay induced by aggregated iron in multiple-spin-echo sequences. We have initially validated the method in agarose phantoms and in human liver explants and shown the feasibility of its application in patients with thalassemia major. Measurement of tissue ferritin iron is a promising new means to rapidly evaluate the effectiveness of iron-chelating regimens. PMID:20712781

Wu, Ed X.; Kim, Daniel; Tosti, Christina L.; Tang, Haiying; Jensen, Jens H.; Cheung, Jerry S.; Feng, Li; Au, Wing-Yan; Ha, Shau-Yin; Sheth, Sujit S.; Brown, Truman R.; Brittenham, Gary M.

2010-01-01

217

Abnormal iron homeostasis and neurodegeneration  

PubMed Central

Abnormal iron metabolism is observed in many neurodegenerative diseases, however, only two have shown dysregulation of brain iron homeostasis as the primary cause of neurodegeneration. Herein, we review one of these - hereditary ferritinopathy (HF) or neuroferritinopathy, which is an autosomal dominant, adult onset degenerative disease caused by mutations in the ferritin light chain (FTL) gene. HF has a clinical phenotype characterized by a progressive movement disorder, behavioral disturbances, and cognitive impairment. The main pathologic findings are cystic cavitation of the basal ganglia, the presence of ferritin inclusion bodies (IBs), and substantial iron deposition. Mutant FTL subunits have altered sequence and length but assemble into soluble 24-mers that are ultrastructurally indistinguishable from those of the wild type. Crystallography shows substantial localized disruption of the normally tiny 4-fold pores between the ferritin subunits because of unraveling of the C-termini into multiple polypeptide conformations. This structural alteration causes attenuated net iron incorporation leading to cellular iron mishandling, ferritin aggregation, and oxidative damage at physiological concentrations of iron and ascorbate. A transgenic murine model parallels several features of HF, including a progressive neurological phenotype, ferritin IB formation, and misregulation of iron metabolism. These studies provide a working hypothesis for the pathogenesis of HF by implicating (1) a loss of normal ferritin function that triggers iron accumulation and overproduction of ferritin polypeptides, and (2) a gain of toxic function through radical production, ferritin aggregation, and oxidative stress. Importantly, the finding that ferritin aggregation can be reversed by iron chelators and oxidative damage can be inhibited by radical trapping may be used for clinical investigation. This work provides new insights into the role of abnormal iron metabolism in neurodegeneration. PMID:23908629

Muhoberac, Barry B.; Vidal, Ruben

2013-01-01

218

Friedreich's ataxia and iron metabolism.  

PubMed

The possible causes of abnormal iron metabolism in patients with Friedreich's ataxia are considered. Reduced expression of a frataxin homologue in yeast is associated with mitochondrial iron accumulation at the expense of cytosolic iron, and the same phenomenon can be demonstrated in these patients. A decrease in cytosolic iron causes the expression of a high-affinity iron-uptake protein, and therefore Friedreich's ataxia can be considered to be a disease of abnormal intracellular iron distribution. Friedreich's ataxia is of autosomal recessive inheritance, and the gene associated with it has been mapped to chromosome 9. This encodes the protein frataxin which regulates mitochondrial iron transport. The commonest mutation causing this disorder is an expanded GAA repeat in the gene for this protein. Different point mutations may account for some of the variations in the phenotypic features that are often found, and these variations are discussed. These findings have raised therapeutic possibilities in a condition for which previously there was no specific treatment. There are intracellular enzymes which are very sensitive to injury by oxygen-free radicals. Treatment has therefore been tried with ibebenone which acts as a free-radical scavenger, with some evidence of improvement. Iron chelating agents, such as deferoxamine, have also been given, but the finding of normal serum iron and ferritin casts doubt on the rationale of this. However the finding that the accumulation of iron in the mitochondria of the cells in patients with this form of ataxia will cause oxidative stress and cell death, gives hope for more effective treatment in the future, possibly with gene therapy. PMID:11111058

Gordon, N

2000-12-01

219

IRON METABOLISM IN EXPERIMENTAL ANEMIA  

PubMed Central

In experimental anemia in dogs due to blood loss the term "available iron" as determined by the dipyridyl test has no physiological significance. Iron salts (100 per cent available by dipyridyl) given in optimum dose (560 mg. per 2 weeks) will cause a net production of 50 to 55 gm. hemoglobin above the control base line in anemic dogs. This means that an iron salt which is rated as 100 per cent available by the dipyridyl test is only 35 per cent physiologically available. The term "available iron (dipyridyl)" simmers down to iron not in the form of hematin compounds. The absorption of this "available iron" is conditioned by a great variety of factors, many unknown at this time. Iron is indeed an elusive sprite whose "availability" or comings and goings cannot be determined in dogs by dipyridyl—perhaps only in part by studies of absorption and excretion. Liver contains "available iron (dipyridyl)" but also organic factors influencing hemoglobin regeneration in anemia as liver ash contains only about 50 per cent the potency of the whole liver. One can readily dissociate the iron from other potent factors in various tissues. Fractions of heart, liver, spleen, and kidney may contain very little iron yet cause much hemoglobin regeneration in anemic dogs. No investigator has reported any condition of copper deficiency in man or dog. In fact, in anemias copper is usually above normal concentration in the liver. It is unlikely, therefore, that in experimental anemia in dogs and in the various anemias of man, any significance attaches to the intake of copper. PMID:19870718

Hahn, P. F.; Whipple, G. H.

1938-01-01

220

Comparison of injectable iron complexes in their ability to iron load tissues and to induce oxidative stress  

Microsoft Academic Search

Iron and copper homeostasis have been studied in various tissues after iron-loading with the polynuclear ferric hydroxide carbohydrate complexes, iron dextran, iron polymaltose, iron sucrose and iron gluconate for four weeks. There were significant increases in the iron content of the different rat tissues compared to controls, with the exception of the brain, which showed no change in its iron

R. Legssyer; P. Geisser; Harry McArdle; R. R. Crichton; R. J. Ward

2003-01-01

221

Serum hepcidin levels in Helicobacter pylori-infected children with iron-deficiency anemia: a case-control study.  

PubMed

Recently, hepcidin, an antimicrobial-like peptide hormone, has evolved as the master regulator of systemic iron homeostasis. Hepcidin integrates signals from diverse physiological inputs, forming a key connection between iron trafficking and response to infection. In this study, we aimed to investigate whether Helicobacter pylori infection modulates serum hepcidin level and response to oral iron therapy in children with iron-deficiency anemia. This was a case-control study including 60 children with iron-deficiency anemia (IDA; 30 H. pylori infected and 30 H. pylori noninfected) and 30 healthy children with comparable age and gender as the control group. Iron parameters including serum iron, ferritin, transferrin, total iron binding capacity, and transferrin saturation and serum hepcidin levels were assessed initially and after 3 months of oral iron therapy for IDA. Compared to the control group, serum hepcidin was significantly lower in H. pylori-noninfected children with IDA (P?iron therapy (P?iron therapy (P?>?0.05). Although hepcidin showed significant positive correlations with serum ferritin, hemoglobin (Hb), iron, and transferrin saturation in noninfected children with IDA (P?iron, and transferrin saturation in H. pylori-infected children with IDA (P?iron therapy in children with iron-deficiency anemia. PMID:23760782

Azab, Seham F A; Esh, Asmaa M H

2013-11-01

222

Microbial acquisition of iron from ferric iron bearing minerals  

SciTech Connect

This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). Iron is a universal requirement for all life forms. Although the fourth most abundant element in the geosphere, iron is virtually insoluble at physiological pH in oxidizing environments, existing mainly as very insoluble oxides and hydroxides. Currently it is not understood how iron is solubilized and made available for biological use. This research project addressed this topic by conducting a series of experiments that utilized techniques from both soil microbiology and mineral surface geochemistry. Microbiological analysis consisted of the examination of metabolic and physiological responses to mineral iron supplements. At the same time mineral surfaces were examined for structural changes brought about by microbially mediated dissolution. The results of these experiments demonstrated that (1) bacterial siderophores were able to promote the dissolution of iron oxides, (2) that strict aerobic microorganisms may use anaerobic processes to promote iron oxide dissolution, and (3) that it is possible to image the surface of iron oxides undergoing microbial dissolution.

Hersman, L.E. [Los Alamos National Lab., NM (United States); Sposito, G. [Univ. of California, Berkeley, CA (United States)

1998-12-31

223

Intravenous Iron Versus Oral Iron in the Treatment of Postpartum Iron Deficiency Anemia  

Microsoft Academic Search

Background: Postpartum anemia can develop after delivery because of unforeseen medical problems during and after delivery which could complicate a mother’s ability to properly care for her newborn child. The current treatment for postpartum anemia is oral iron supplementation but this treatment has been associated with several gastrointestinal side effects. Alternative treatments include blood transfusions and intravenous (IV) iron therapy.

Meghan Crowley

2010-01-01

224

Influence of iron doping on spatial soliton formation and fixing in lithium niobate crystals  

NASA Astrophysics Data System (ADS)

We analyse the feasibility of using iron-doping in lithium niobate in order to stabilize and permanently fix light-induced integrated structures. General 3D optical interconnections were realized in bulk lithium niobate crystals by means of soliton waveguides exploiting the enhanced photorefractive properties obtainable using specific iron doping. We report an enhancement of the photorefractive properties in doped crystals that can be considered for permanently fixing the integrated circuits. This work opens new directions for realizing permanent self-assembled and self-aligned integrated electro-optic devices and photonic circuits.

Fazio, E.; Zaltron, A.; Belardini, A.; Argiolas, N.; Sada, C.

2014-11-01

225

A methodology to estimate remaining service life of grey cast iron water mains  

Microsoft Academic Search

The decision to repair, renew, or replace existing old grey cast iron mains is typically based on performance indicators such as structural integrity, hydraulic efficiency, system reliability, and water quality. Structural integrity (of - ten quantified as the number of main breaks per kilometre or mile per year) is the most common performance indica- tor. However, these indicators represent past

Balvant Rajani; Jon Makar

2000-01-01

226

Iron metabolism: current facts and future directions  

PubMed Central

Iron metabolism has been intensively examined over the last decade and there are many new players in this field which are worth to be introduced. Since its discovery many studies confirmed role of liver hormone hepcidin as key regulator of iron metabolism and pointed out liver as the central organ of system iron homeostasis. Liver cells receive multiple signals related to iron balance and respond by transcriptional regulation of hepcidin expression. This liver hormone is negative regulator of iron metabolism that represses iron efflux from macrophages, hepatocytes and enterocytes by its binding to iron export protein ferroportin. Ferroportin degradation leads to cellular iron retention and decreased iron availability. At level of a cell IRE/IRP (iron responsive elements/iron responsive proteins) system allows tight regulation of iron assimilation that prevents an excess of free intracellular iron which could lead to oxidative stress and damage of DNA, proteins and lipid membranes by ROS (reactive oxygen species). At the same time IRE/IRP system provides sufficient iron in order to meet the metabolic needs. Recently a significant progress in understanding of iron metabolism has been made and new molecular participants have been characterized. Article gives an overview of the current understanding of iron metabolism: absorption, distribution, cellular uptake, release, and storage. We also discuss mechanisms underlying systemic and cellular iron regulation with emphasis on central regulatory hormone hepcidin. PMID:23092063

Tandara, Leida; Salamunic, Ilza

2012-01-01

227

Southern Ocean Iron Experiment (SOFex)  

SciTech Connect

The Southern Ocean Iron Experiment (SOFeX) was an experiment decades in the planning. It's implementation was among the most complex ship operations that SIO has been involved in. The SOFeX field expedition was successful in creating and tracking two experimentally enriched areas of the Southern Ocean, one characterized by low silicic acid, one characterized by high silicic acid. Both experimental sites were replete with abundant nitrate. About 100 scientists were involved overall. The major findings of this study were significant in several ways: (1) The productivity of the southern ocean is limited by iron availability. (2) Carbon uptake and flux is therefore controlled by iron availability (3) In spite of low silicic acid, iron promotes non-silicious phytoplankton growth and the uptake of carbon dioxide. (4) The transport of fixed carbon from the surface layers proceeds with a C:N ratio that would indicate differential remineralization of nitrogen at shallow depths. (5) These finding have major implications for modeling of carbon export based on nitrate utilization. (6) The general results of the experiment indicate that, beyond other southern ocean enrichment experiments, iron inputs have a much wider impact of productivity and carbon cycling than previously demonstrated. Scientific presentations: Coale, K., Johnson, K, Buesseler, K., 2002. The SOFeX Group. Eos. Trans. AGU 83(47) OS11A-0199. Coale, K., Johnson, K. Buesseler, K., 2002. SOFeX: Southern Ocean Iron Experiments. Overview and Experimental Design. Eos. Trans. AGU 83 (47) OS22D-01. Buesseler, K.,et al. 2002. Does Iron Fertilization Enhance Carbon Sequestration? Particle flux results from the Southern Ocean Iron Experiment. Eos. Trans. AGU 83 (47), OS22D-09. Johnson, K. et al. 2002. Open Ocean Iron Fertilization Experiments From IronEx-I through SOFeX: What We Know and What We Still Need to Understand. Eos. Trans. AGU 83 (47), OS22D-12. Coale, K. H., 2003. Carbon and Nutrient Cycling During the Southern Ocean Iron Enrichment Experiments. Seattle, WA. Geological Society of America. Coale, K., 2003. Open Ocean Iron Enrichment Experiments: What they have told us, what they have not. American Society for Limnology and Oceanography and The Oceanography Society, Honolulu, February 2004. Coale, K., 2004. Recent Research from the Southern Ocean Iron Experiment (SOFeX), in Taking the Heat: What is the impact of ocean fertilization on climate and ocean ecology? Science of earth and sky. AAAS, February 12-16, Seattle, WA

Coale, Kenneth H.

2005-07-28

228

Iron indices: what do they really mean?  

PubMed

Routine monitoring of body iron stores is an essential component of overall management for the patient on hemodialysis. Adequate iron levels are important for the prevention and treatment of iron-deficiency anemia, which is associated with reduced physical functioning, cardiovascular disease, and poor quality of life. Hemodialysis patients are at especially high risk for iron-deficiency anemia, owing to continuous blood losses and supraphysiologic levels of erythropoiesis driven by recombinant human erythropoietin therapy. Unfortunately, the accurate determination of iron status in these patients can be a challenging task, which is made more difficult by inflammation, infections, and the large number of comorbid conditions that can affect commonly used indices of body iron stores. Despite their limitations, transferrin saturation (TSAT) and serum ferritin remain the cornerstones of iron status assessment. Because these values can be altered by a number of non-iron-related factors, it is necessary to go beyond these measures and draw upon additional sources of information to determine the patient's iron status. Other important factors to consider when assessing the need for iron therapy include evidence of underlying inflammatory processes that may block iron mobilization and distort the standard iron indices, the results of alternative iron indices, and the patient's recent history of iron administration. Frequently, the response to a gram of intravenous (i.v.) iron is a safe and effective way to determine the role of iron deficiency in the anemia of the problematic patient. The chronic inflammatory state associated with malnutrition and clinical or subclinical infections substantially increases the risk of misdiagnosing the patient with iron overload and may place the patient at risk of iron deficiency owing to inappropriate withdrawal of i.v. iron therapy. To avoid the risks of withholding iron therapy, the nephrologist must keep this relationship in mind whenever serum ferritin testing suggests replete iron stores, whereas TSAT testing suggests insufficient iron availability. PMID:16830699

Coyne, D

2006-05-01

229

Iron precipitation at oxygen related bulk defects in Czochralski silicon  

NASA Astrophysics Data System (ADS)

Behavior of iron atoms in silicon during a simulated integrated circuit device fabrication process was examined. The results from the electron microscopic and deep-level transient spectroscopic analysis indicate that iron at concentrations below the solubility limit precipitates at a bulk stacking fault containing an oxide precipitate. Based upon the defect morphology and the eutectoid temperature of the ?-FeSi2 phase, it is suggested that iron precipitation occurs during the cooling down period after a high-temperature treatment. The result shows that iron may react with oxygen atoms in the oxide precipitate via a Fe2O3 phase transformation which in turn causes a change in the precipitate morphology. In this study, it is suggested that iron precipitation at the bulk defects is fundamentally different from that of other transition metals such as nickel and copper where the precipitation occurs either along the Frank partial dislocations of the bulk stacking fault or at the punch-out dislocation loops originating at the oxide precipitate interface.

Wijaranakula, W.

1996-04-01

230

Development of an integrated in-situ remediation technology. Topical report for Task {number_sign}3.2 entitled, ``Modeling and iron dechlorination studies`` (September 26, 1994--August 31, 1997)  

SciTech Connect

Contamination in low-permeability soils poses a significant technical challenge to in-situ remediation efforts. Poor accessibility to the contaminants and difficulty in delivery of treatment reagents have rendered existing in-situ treatments such as bioremediation, vapor extraction, and pump and treat rather ineffective when applied to low-permeability soils present at many contaminated sites. The technology is an integrated in-situ treatment in which established geotechnical methods are used to install degradation zones directly in the contaminated soil, and electro-osmosis is utilized to move the contaminants back and forth through those zones until the treatment is complete. The present Topical Report for Task {number_sign}3.2 summarizes the modeling and dechlorination research conducted by General Electric Research and Development.

Shapiro, A.P.; Sivavec, T.M.; Principe, J.M. [General Electric Research and Development, Schenectady, NY (United States)

1997-11-01

231

Antimony in iron meteorites  

NASA Technical Reports Server (NTRS)

Sb concentrations determined by radiochemical neutron activation analysis in 60 iron meteorites range from 0.2 ng/g to 36 microg/g. The meteorites with the highest Sb concentrations are those of the nonmagmatic groups IAB and IIICD, while meteorites with the lowest Sb concentrations are found in groups IVA and IVB. In all groups Sb is positively correlated with Ni; slopes on log Sb vs log Ni plots decrease with increasing Ni. This decrease may reflect an increasing tendency to avoid schreibersite during the analysis of high-Ni meteorites because Sb partitions strongly into schreibersite. It is found that schreibersite from New Westville is enriched in Cr, Ni, Ge, As, Sb, and Au and depleted in Fe, Co, Ir; the Sb content in schreibersite is 540 times higher than the bulk metal value.

Willis, J.

1981-01-01

232

Iron Mountain Electromagnetic Results  

SciTech Connect

Iron Mountain Mine is located seventeen miles northwest of Redding, CA. After the completion of mining in early 1960s, the mine workings have been exposed to environmental elements which have resulted in degradation in water quality in the surrounding water sheds. In 1985, the EPA plugged ore stoops in many of the accessible mine drifts in an attempt to restrict water flow through the mine workings. During this process little data was gathered on the orientation of the stoops and construction of the plugs. During the last 25 years, plugs have begun to deteriorate and allow acidic waters from the upper workings to flow out of the mine. A team from Idaho National Laboratory (INL) performed geophysical surveys on a single mine drift and 3 concrete plugs. The project goal was to evaluate several geophysical methods to determine competence of the concrete plugs and orientation of the stopes.

Gail Heath

2012-07-01

233

Cellular distribution and localisation of iron in adult rat brain ( substantia nigra)  

NASA Astrophysics Data System (ADS)

Iron appears to be one of the main factors in the metal induced neurodegeneration. Quantitative information on cellular, sub-cellular and cell specific distributions of iron is therefore important to assess. The investigations reported here were carried out on a brain from an adult rat. Therefore, 6 ?m thick embedded, unstained brain sections containing the midbrain ( substantia nigra, SN) were analysed. Particle induced X-ray emission (PIXE) using a focussed proton beam (beam - diameter app. 1 ?m) was performed to determine the quantitative iron content on a cellular and sub-cellular level. The integral analysis shows that the iron content in the SN pars reticulata is twice as high than in the SN pars compacta. The analysis of the iron content on the cellular level revealed no remarkable differences between glia cells and neurons. This is in contrast to other studies using staining techniques.

Meinecke, Ch.; Morawski, M.; Reinert, T.; Arendt, T.; Butz, T.

2006-08-01

234

Nanofiltration and Fenton's process over iron shavings for surfactants removal.  

PubMed

The presence of surfactants in wastewater composition tends to jeopardize the efficiency of the traditional aerobic treatment processes. In this regard, the application of Fenton's reaction and nanofiltration as single processes and integrated (nanofiltration followed by Fenton's process) was investigated on the abatement of a solution containing two surfactants usually found in effluents coming from detergent industry (dodecylbenzene--DDB and sodium lauryl ether sulphate--SLES). The potential of a solid waste (iron shavings) as catalyst in the Fenton's process was evaluated and the reaction system was optimized regarding the key operating parameters (iron and hydrogen peroxide concentration and pH). The highest chemical oxygen demand (COD) degradation (66%) was attained for pH 3, [H2O2] = 32 mM and 50 g/L of iron shavings. Besides, it was concluded that oxidation was due to hydroxyl radicals adsorbed on the metal surface even if bulk interaction between hydrogen peroxide and dissolved iron cannot be neglected. The main variables ruling nanofiltration were evaluated (pH, temperature and cross-flow rate). Eighty-four percent of COD rejection was determined at pH 7.5, cross-flow 14.4 cm3 s(-1), 20 degrees C and 15 bar of pressure drop. Finally, nanofiltration followed by Fenton's process under the best conditions was integrated; however, no significant improvement was attained with 85% of COD being globally removed. PMID:25145192

Martins, Rui C; Nunes, Marta; Gando-Ferreira, Licínio M; Quinta-Ferreira, Rosa M

2014-01-01

235

Formation of Iron Nanoparticles and Increase in Iron Reactivity in  

E-print Network

by an ascorbate solution after simulated cloud processing. In addition, the sequential extractions. Introduction Iron (Fe) is an important micronutrient that can limit phytoplankton growth in the ocean. While

Benning, Liane G.

236

Comparison of polysaccharide iron complexes used as iron supplements.  

PubMed

An oral hematinic marketed as "water soluble polysaccharide iron complex" (Vitaline Formulas) has been characterized using x-ray powder diffraction and Mössbauer spectroscopy. Another polysaccharide iron complex marketed as Niferex (Central Pharmaceuticals) has been previously studied by us and found to have a core similar to ferrihydrite, but with some long-range order of the mineral akaganéite, beta-FeOOH. The latter is seen in other ferric carbohydrate complexes synthesized by the hydrolysis of FeCl3. This commercial product, however, is very different and has a mixture of iron components including hematite (alpha-Fe2O3) magnetite (Fe3O4), goethite (alpha-FeOOH), iron metal, and a ferrous salt. PMID:7775981

Coe, E M; Bowen, L H; Speer, J A; Bereman, R D

1995-03-01

237

Iron line afterglows: general constraints  

E-print Network

The discovery of a powerful and transient iron line feature in the X-ray afterglow spectra of gamma-ray bursts would be a major breakthrough for understanding the nature of their progenitors, strongly suggesting the presence of a large, iron rich, mass in the vicinity of the burst event. Model-independent limits to the size and the mass of the the iron line emitting region are derived and discussed. We also discuss how these results can be used to constrain the amount of beaming or anisotropy of the burst emission.

Gabriele Ghisellini; Davide Lazzati; Sergio Campana

1999-06-14

238

Iron incorporation and post-malaria anaemia  

Technology Transfer Automated Retrieval System (TEKTRAN)

Iron supplementation is employed to treat post-malarial anaemia in environments where iron deficiency is common. Malaria induces an intense inflammatory reaction that stalls reticulo-endothelial macrophagal iron recycling from haemolysed red blood cells and inhibits oral iron absorption, but the mag...

239

Iron oxyhydroxide mineralization on microbial extracellular polysaccharides  

E-print Network

Iron oxyhydroxide mineralization on microbial extracellular polysaccharides Clara S. Chan a Iron biominerals can form in neutral pH microaerophilic environments where microbes both catalyze iron, and high-resolution transmission electron microscopy (HRTEM). We focused on iron microbial mat samples from

240

Hydrolysis of soybean protein improves iron bioavailability  

Technology Transfer Automated Retrieval System (TEKTRAN)

Iron is an important trace metal element in human body. Iron deficiency affects human health, especially pregnant women and children. Soybean protein is a popular food in Asia and can contain a high amount of iron (145.70±0.74 ug/g); however, it is usually reported as an inhibitor of iron absorption...

241

THE IRON PROJECT Anil K. Pradhan  

E-print Network

THE IRON PROJECT Anil K. Pradhan Department of Astronomy, The Ohio State University, Columbus, Ohio and application of these methods is the aim of the Iron Project. At present the primary focus is on collisional processes for all ions of iron, Fe I -- FeXXVI, and other iron­peak elements; new work on radiative

Pradhan, Anil

242

The Saugus Iron Works Blast Furnace  

USGS Multimedia Gallery

A view of the Saugus Iron Works blast furnace, which smelted the iron from limonite, an iron ore. The limonite formed in nearby bogs, and was heated in the blast furnace until the iron melted and ran out the bottom of the furnace. ...

243

Limonite Pile at Saugus Iron Works  

USGS Multimedia Gallery

A pile of limonite rocks used in the iron smelting process. Limonite is a well-known iron ore that has been mined for iron for many thousands of years. At the Saugus Iron Works, the limonite was found in nearby bogs....

244

Acquisition of Iron by Gardnerella vaginalis  

Microsoft Academic Search

Six Gardnerella vaginalis strains were examined for the ability to utilize various iron-containing compounds as iron sources. In a plate bioassay, all six strains acquired iron from ferrous chloride, ferric chloride, ferrous sulfate, ferric ammonium citrate, ferrous ammonium sulfate, bovine and equine hemin, bovine catalase, and equine, bovine, rabbit, and human hemoglobin. All six strains also acquired iron from human

GREGORY P. JAROSIK; CAROL BETH LAND; PATRICE DUHON

1998-01-01

245

Saugus Iron Works Forge and Mill  

USGS Multimedia Gallery

A view of the forge at Saugus Iron Works, as well as the rolling and slitting mill. The forge used a large hammer to compress the iron. Forging strenghened the iron, which, right out of the blast furnace, was brittle. The rolling and slitting mill would make bars of iron that could be cut into thing...

246

Flow Injection Spectrophotometric Determination Iron(II) and Iron(III) in Environmental Samples  

Microsoft Academic Search

A flow injection spectrophotometric method has been developed for the determination of iron (II) and iron (III) in environmental waters. The procedure was based on the reduction of iron (III) to iron (II) by ascorbic acid and complexation of iron (II) with 4-(2-pyridylazo) resorcinol, with the presence of ammonia, the absorbance was measured at 718 nm, difference from the complexation

Gong Zheng-jun; Chen Guo-he; Zhang Xin-shen

2009-01-01

247

49 CFR 192.373 - Service lines: Cast iron and ductile iron.  

...2014-10-01 2014-10-01 false Service lines: Cast iron and ductile iron. 192.373 Section 192...and Service Lines § 192.373 Service lines: Cast iron and ductile iron. (a) Cast or ductile iron pipe less than 6 inches...

2014-10-01

248

Hair iron content: possiblemarker to complement monitoringtherapy of iron deficiencyin patients with chronic inflammatorybowel diseases?  

Microsoft Academic Search

Measurements of the concentrations of iron in hair from 10 patients with chronic inflammatory bowel diseases and from 10 healthy controls showed that the iron concentra- tions were significantly (P <0.05) lower in patients before iron intake than in controls. Three weeks after beginning iron treatment, the hair iron concentrations were found to be significantly correlated (r = 0.68; P

FLORIAN RENNER; STEFAN SU; JURGEN SCH

249

Performance characteristics of the Dimension RxL iron and total iron-binding capacity methods  

Microsoft Academic Search

Background: Measurements of serum iron and total iron-binding capacity (TIBC) can be used to aid the diagnosis of iron deficiency and iron overload states. A variety of different methods for these measurements are commercially available. Methods: Linearity, imprecision and hemoglobin interference of homogeneous iron and TIBC methods on a Dimension® RxL analyzer were assessed. Method comparison studies were performed with

Barun K. De; William L. Roberts

2003-01-01

250

Hepatotoxic iron storage in patients with chronic hepatitis C but no hepatic iron detectable histochemically  

Microsoft Academic Search

The accumulation of iron plays a role in the pathogenesis of chronic hepatitis C. Therefore, even slight excesses of iron should be measured if possible. Eight patients were entered in this study who were negative for histochemical tests for iron in the liver. X-ray microanalysis showed that all eight patients had iron stored as scattered hepatocyte hemosiderin. Hemosiderin iron index

Motoyoshi Yano; Hisao Hayashi; Shinya Wakusawa; Toshikuni Takikawa; Ritsuko Ikeda

1997-01-01

251

Comparison of polysaccharide iron complexes used as iron supplements  

Microsoft Academic Search

An oral hematinic marketed as “water soluble polysaccharide iron complex” (Vitaline Formulas) has been characterized using x-ray powder diffraction and Mössbauer spectroscopy. Another polysaccharide iron complex marketed as Niferex (Central Pharmaceuticals) has been previously studied by us and found to have a core similar to similar to ferrihydrite, but with some long-range order of the mineral akaganéite, ?-FeOOH. The latter

Emma M. Coe; Lawrence H. Bowen; J. Alexander Speer; Robert D. Bereman

1995-01-01

252

Microorganisms pumping iron: anaerobic microbial iron oxidation and reduction  

Microsoft Academic Search

Iron (Fe) has long been a recognized physiological requirement for life, yet for many microorganisms that persist in water, soils and sediments, its role extends well beyond that of a nutritional necessity. Fe(II) can function as an electron source for iron-oxidizing microorganisms under both oxic and anoxic conditions and Fe(III) can function as a terminal electron acceptor under anoxic conditions

Karrie A. Weber; Laurie A. Achenbach; John D. Coates

2006-01-01

253

The pathophysiology of transfusional iron overload.  

PubMed

The pathophysiologic consequences of transfusional iron overload (TIO) as well as the benefits of iron chelation therapy are best described in thalassemia major, although TIO is increasingly seen in other clinical settings. These consequences broadly reflect the levels and distribution of excess storage iron in the heart, endocrine tissues, and liver. TIO also increases the risk of infection, due to increased availability of labile iron to microorganisms. The authors suggest that extrahepatic iron distribution, and hence toxicity, is influenced by balance between generation of nontransferrin-bound iron from red cell catabolism and the utilization of transferrin iron by the erythron. PMID:25064708

Porter, John B; Garbowski, Maciej

2014-08-01

254

Method for reducing iron losses in an iron smelting process  

DOEpatents

A process of smelting iron that comprises the steps of: a) introducing a source of iron oxide, oxygen, nitrogen, and a source of carbonaceous fuel to a smelting reactor, at least some of said oxygen being continuously introduced through an overhead lance; b) maintaining conditions in said reactor to cause (i) at least some of the iron oxide to be chemically reduced, (ii) a bath of molten iron to be created and stirred in the bottom of the reactor, surmounted by a layer of slag, and (iii) carbon monoxide gas to rise through the slag; c) causing at least some of said carbon monoxide to react in the reactor with the incoming oxygen, thereby generating heat for reactions taking place in the reactor; and d) releasing from the reactor an offgas effluent, is run in a way that keeps iron losses in the offgas relatively low. After start-up of the process is complete, steps (a) and (b) are controlled so as to: e) keep the temperature of the molten iron at or below about 1550.degree. C. and f) keep the slag weight at or above about 0.8 tonne per square meter.

Sarma, Balu (Airmont, NY); Downing, Kenneth B. (Greenville, SC)

1999-01-01

255

Method for reducing iron losses in an iron smelting process  

DOEpatents

A process of smelting iron that comprises the steps of: (a) introducing a source of iron oxide, oxygen, nitrogen, and a source of carbonaceous fuel to a smelting reactor, at least some of said oxygen being continuously introduced through an overhead lance; (b) maintaining conditions in said reactor to cause (1) at least some of the iron oxide to be chemically reduced, (2) a bath of molten iron to be created and stirred in the bottom of the reactor, surmounted by a layer of slag, and (3) carbon monoxide gas to rise through the slag; (c) causing at least some of said carbon monoxide to react in the reactor with the incoming oxygen, thereby generating heat for reactions taking place in the reactor; and (d) releasing from the reactor an offgas effluent, is run in a way that keeps iron losses in the offgas relatively low. After start-up of the process is complete, steps (a) and (b) are controlled so as to: (1) keep the temperature of the molten iron at or below about 1550 C and (2) keep the slag weight at or above about 0.8 ton per square meter. 13 figs.

Sarma, B.; Downing, K.B.

1999-03-23

256

IRON-TOLERANT CYANOBACTERIA: IMPLICATIONS FOR ASTROBIOLOGY  

NASA Technical Reports Server (NTRS)

The review is dedicated to the new group of extremophiles - iron tolerant cyanobacteria. The authors have analyzed earlier published articles about the ecology of iron tolerant cyanobacteria and their diversity. It was concluded that contemporary iron depositing hot springs might be considered as relative analogs of Precambrian environment. The authors have concluded that the diversity of iron-tolerant cyanobacteria is understudied. The authors also analyzed published data about the physiological peculiarities of iron tolerant cyanobacteria. They made the conclusion that iron tolerant cyanobacteria may oxidize reduced iron through the photosystem of cyanobacteria. The involvement of both Reaction Centers 1 and 2 is also discussed. The conclusion that iron tolerant protocyanobacteria could be involved in banded iron formations generation is also proposed. The possible mechanism of the transition from an oxygenic photosynthesis to an oxygenic one is also discussed. In the final part of the review the authors consider the possible implications of iron tolerant cyanobacteria for astrobiology.

Brown, Igor I.; Allen, Carlton C.; Mummey, Daniel L.; Sarkisova, Svetlana A.; McKay, David S.

2006-01-01

257

Process for the synthesis of iron powder  

DOEpatents

A process for preparing iron powder suitable for use in preparing the iron-potassium perchlorate heat-powder fuel mixture used in thermal batteries, comprises preparing a homogeneous, dense iron oxide hydroxide precipitate by homogeneous precipitation from an aqueous mixture of a ferric salt, formic or sulfuric acid, ammonium hydroxide and urea as precipitating agent; and then reducing the dense iron oxide hydroxide by treatment with hydrogen to prepare the iron powder.

Welbon, William W. (Belleair, FL)

1983-01-01

258

Acid mine drainage biogeochemistry at Iron Mountain, California  

Microsoft Academic Search

: The Richmond Mine at Iron Mountain, Shasta County, California, USA provides an excellent opportunity to study the chemical and biological controls on acid mine drainage (AMD) generation in situ, and to identify key factors controlling solution chemistry. Here we integrate four years of field-based geochemical data with 16S rRNA gene clone libraries and rRNA probe-based studies of microbial population

Gregory K. Druschel; Brett J. Baker; Thomas M. Gihring; Jillian F. Banfield

2004-01-01

259

Iron catalyzed coal liquefaction process  

DOEpatents

A process is described for the solvent refining of coal into a gas product, a liquid product and a normally solid dissolved product. Particulate coal and a unique co-catalyst system are suspended in a coal solvent and processed in a coal liquefaction reactor, preferably an ebullated bed reactor. The co-catalyst system comprises a combination of a stoichiometric excess of iron oxide and pyrite which reduce predominantly to active iron sulfide catalysts in the reaction zone. This catalyst system results in increased catalytic activity with attendant improved coal conversion and enhanced oil product distribution as well as reduced sulfide effluent. Iron oxide is used in a stoichiometric excess of that required to react with sulfur indigenous to the feed coal and that produced during reduction of the pyrite catalyst to iron sulfide.

Garg, Diwakar (Macungie, PA); Givens, Edwin N. (Bethlehem, PA)

1983-01-01

260

Neurodegeneration with Brain Iron Accumulation  

MedlinePLUS

NINDS Neurodegeneration with Brain Iron Accumulation Information Page Synonym(s): Hallervorden-Spatz Disease, Pantothenate Kinase-Associated Neurodegeneration Table of Contents (click to jump to sections) What ...

261

Luminescent iron clusters in solution  

NASA Astrophysics Data System (ADS)

Metal clusters, composed of a few atoms at the core, exhibit unique properties and have potential applications. Although atomically precise clusters of noble metals have been synthesized, analogous systems of reactive metals, such as iron, have not been realized in solution due to high reactivity. Here we report the synthesis and characterization of novel iron clusters in the hemoglobin matrix that are highly luminescent (quantum yield 10% at 565 nm). The super-paramagnetic iron clusters, after successful ligand exchange from protein and phase transfer from water to chloroform using tri-octylphosphineoxide (TOPO), were detected as [Fe10(TOPO)3(H2O)3]+, [Fe13(TOPO)2(H2O)]+ and [Fe8(TOPO)(H2O)2]+ by mass spectrometry. This study lays the groundwork for exploiting unique properties of soluble iron clusters.Metal clusters, composed of a few atoms at the core, exhibit unique properties and have potential applications. Although atomically precise clusters of noble metals have been synthesized, analogous systems of reactive metals, such as iron, have not been realized in solution due to high reactivity. Here we report the synthesis and characterization of novel iron clusters in the hemoglobin matrix that are highly luminescent (quantum yield 10% at 565 nm). The super-paramagnetic iron clusters, after successful ligand exchange from protein and phase transfer from water to chloroform using tri-octylphosphineoxide (TOPO), were detected as [Fe10(TOPO)3(H2O)3]+, [Fe13(TOPO)2(H2O)]+ and [Fe8(TOPO)(H2O)2]+ by mass spectrometry. This study lays the groundwork for exploiting unique properties of soluble iron clusters. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr05784d

Goswami, Nirmal; Baksi, Ananya; Giri, Anupam; Xavier, Paulrajpillai Lourdu; Basu, Gautam; Pradeep, Thalappil; Pal, Samir Kumar

2014-01-01

262

Properties of iron silicide nanowires  

Microsoft Academic Search

Iron silicide nanowires (NWs) were grown and studied in this work. We have found that self-assembled epitaxial iron silicide NWs grown on Si(110) can be converted from a cubic s-phase to an orthorhombic beta-phase FeSi 2 by annealing at 800°C for 1 hour. The transformation temperature of 800°C is considerably higher than that observed in thin films (200-500°C), due to

Shengde Liang

2006-01-01

263

Ironing out the phosphorus problem  

Microsoft Academic Search

Control of serum phosphorus remains a vexing problem in chronic kidney disease. Although novel dialysis regimens may provide excellent phosphorus control, phosphate binders remain necessary for most dialysis patients. Block et al. present a phase I clinical trial examining the safety and efficacy of SBR759, a novel non-calcium, iron-based phosphate binder. Although the risks of iron accumulation and hypocalcemia must

Joshua J Zaritsky; Isidro B Salusky

2010-01-01

264

Simultaneous Measurements of Temperature and Iron-Slag Ratio at Taphole of Blast Furnace  

NASA Astrophysics Data System (ADS)

As the initial process in an integrated steel-making plant, molten iron is produced in a blast furnace. The molten iron has a temperature between 1700 K and 1900 K. The outflow stream discharged from a taphole comprises the molten iron and slag (which is a mixture of molten oxides). Monitoring of the stream temperature is important because it has information on the thermal condition inside the blast furnace. A newly developed simultaneous measurement technique for temperature and iron-slag ratio is reported. A monochromatic CCD camera with a short exposure time is used to obtain a thermal image of the rapidly moving stream. The thermal image has a marble-like pattern caused by the physical separation of the iron and slag and their different optical properties. Iron thermometry is realized by automatically detecting the peak of the iron gray-level distribution on a histogram. Meanwhile, the thermal radiance of the semitransparent slag varies as a function of the thickness. The slag temperature is calculated from the maximum gray level, presuming that the emissivity of the slag is constant at a thick slag part. The slag ratio is measured by counting the number of pixels on the histogram. A field test was carried out at an operating blast furnace. The iron temperature, slag temperature, and slag ratio were successfully measured. This multiple image measurement is expected to be the new information source for stable blast furnace operation.

Sugiura, M.; Shinotake, A.; Nakashima, M.; Omoto, N.

2014-07-01

265

Crosstalk between Iron Metabolism and Erythropoiesis  

PubMed Central

Iron metabolism and erythropoiesis are inextricably linked. The majority of iron extracted from circulation daily is used for hemoglobin synthesis. In the last 15 years, major advances have been made in understanding the pathways regulating iron metabolism. Hepcidin is a key regulator of iron absorption and recycling and is itself regulated by erythropoiesis. While several viable candidates have been proposed, elucidating the “erythroid regulator” of hepcidin continues to generate significant experimental activity in the field. Although the mechanism responsible for sensing iron demand for erythropoiesis is still incompletely understood, evaluating diseases in which disordered erythropoiesis and/or iron metabolism are showcased has resulted in a more robust appreciation of potential candidates coordinated erythroid iron demand with regulators of iron supply. We present data drawn from four different conditions—iron deficiency, congenital hypotransferrinemia, beta-thalassemia, and hereditary hemochromatosis—both in human and non-human models of disease, together suggesting that erythroid iron demand exerts a stronger influence on circulating iron supply than systemic iron stores. Greater understanding of the interplay between the key factors involved in the regulation of iron metabolism and erythropoiesis will help develop more effective therapies for disorders of iron overload, iron deficiency, and hemoglobin synthesis. PMID:20631898

Li, Huihui; Ginzburg, Yelena Z.

2010-01-01

266

Iron, Oxidative Stress and Gestational Diabetes  

PubMed Central

Both iron deficiency and hyperglycemia are highly prevalent globally for pregnant women. Iron supplementation is recommended during pregnancy to control iron deficiency. The purposes of the review are to assess the oxidative effects of iron supplementation and the potential relationship between iron nutrition and gestational diabetes. High doses of iron (~relative to 60 mg or more daily for adult humans) can induce lipid peroxidation in vitro and in animal studies. Pharmaceutical doses of iron supplements (e.g., 10× RDA or more for oral supplements or direct iron supplementation via injection or addition to the cell culture medium) for a short or long duration will induce DNA damage. Higher heme-iron intake or iron status measured by various biomarkers, especially serum ferritin, might contribute to greater risk of gestational diabetes, which may be mediated by iron oxidative stress though lipid oxidation and/or DNA damage. However, information is lacking about the effect of low dose iron supplementation (?60 mg daily) on lipid peroxidation, DNA damage and gestational diabetes. Randomized trials of low-dose iron supplementation (?60 mg daily) for pregnant women are warranted to test the relationship between iron oxidative stress and insulin resistance/gestational diabetes, especially for iron-replete women. PMID:25255832

Zhuang, Taifeng; Han, Huijun; Yang, Zhenyu

2014-01-01

267

Iron Necessity: The Secret of Wolbachia's Success?  

PubMed Central

The bacterium Wolbachia (order Rickettsiales) is probably the world's most successful vertically-transmitted symbiont, distributed among a staggering 40% of terrestrial arthropod species. Wolbachia has great potential in vector control due to its ability to manipulate its hosts' reproduction and to impede the replication and dissemination of arboviruses and other pathogens within haematophagous arthropods. In addition, the unexpected presence of Wolbachia in filarial nematodes of medical and veterinary importance has provided an opportunity to target the adult worms of Wuchereria bancrofti, Onchocerca volvulus, and Dirofilaria immitis with safe drugs such as doxycycline. A striking feature of Wolbachia is its phenotypic plasticity between (and sometimes within) hosts, which may be underpinned by its ability to integrate itself into several key processes within eukaryotic cells: oxidative stress, autophagy, and apoptosis. Importantly, despite significant differences in the genomes of arthropod and filarial Wolbachia strains, these nexuses appear to lie on a continuum in different hosts. Here, we consider how iron metabolism may represent a fundamental aspect of host homeostasis that is impacted by Wolbachia infection, connecting disparate pathways ranging from the provision of haem and ATP to programmed cell death, aging, and the recycling of intracellular resources. Depending on how Wolbachia and host cells interact across networks that depend on iron, the gradient between parasitism and mutualism may shift dynamically in some systems, or alternatively, stabilise on one or the other end of the spectrum. PMID:25329055

Gill, Alessandra Christina; Darby, Alistair C.; Makepeace, Benjamin L.

2014-01-01

268

Iron necessity: the secret of Wolbachia's success?  

PubMed

The bacterium Wolbachia (order Rickettsiales) is probably the world's most successful vertically-transmitted symbiont, distributed among a staggering 40% of terrestrial arthropod species. Wolbachia has great potential in vector control due to its ability to manipulate its hosts' reproduction and to impede the replication and dissemination of arboviruses and other pathogens within haematophagous arthropods. In addition, the unexpected presence of Wolbachia in filarial nematodes of medical and veterinary importance has provided an opportunity to target the adult worms of Wuchereria bancrofti, Onchocerca volvulus, and Dirofilaria immitis with safe drugs such as doxycycline. A striking feature of Wolbachia is its phenotypic plasticity between (and sometimes within) hosts, which may be underpinned by its ability to integrate itself into several key processes within eukaryotic cells: oxidative stress, autophagy, and apoptosis. Importantly, despite significant differences in the genomes of arthropod and filarial Wolbachia strains, these nexuses appear to lie on a continuum in different hosts. Here, we consider how iron metabolism may represent a fundamental aspect of host homeostasis that is impacted by Wolbachia infection, connecting disparate pathways ranging from the provision of haem and ATP to programmed cell death, aging, and the recycling of intracellular resources. Depending on how Wolbachia and host cells interact across networks that depend on iron, the gradient between parasitism and mutualism may shift dynamically in some systems, or alternatively, stabilise on one or the other end of the spectrum. PMID:25329055

Gill, Alessandra Christina; Darby, Alistair C; Makepeace, Benjamin L

2014-10-01

269

Oligodendrogenesis: the role of iron.  

PubMed

Iron seems to be an essential factor in myelination and oligodendrocyte (OLGc) biology. However, the specific role of iron in these processes remains to be elucidated. Iron deficiency (ID) imposed to developing rats has been a relevant model to understand the role of iron in oligodendrogenesis and myelination. During early development ID causes specific changes in myelin composition, including a lower relative content of cholesterol, proteolipid protein (PLP), and myelin basic protein 21 (MBP21). These changes could be a consequence of the adverse effects of ID on OLGc development and function. We subsenquently studied the possible corrective effect of a single intracranial injection (ICI) of apotransferrin (aTf) on myelin formation in ID rats OLGc migration and differentiation after an ICI of aTf was evaluated at 3 days of age. ID increased the number of proliferating and undifferentiated cells in the corpus callosum (CC), while a single aTf injection reverts these effects, increasing the number of mature cells and myelin formation. Overall, results of a series of studies supports the concept that iron may affect OLGc development at early stages of embryogenesis rather than during late development. Myelin composition is altered by a limited iron supply, changes that can be reverted by a single injection of aTf. PMID:20336710

Badaracco, Maria Elvira; Siri, Maria Victoria Rosato; Pasquini, Juana Maria

2010-01-01

270

Flow injection-assisted optical sensor for determination of iron(II) and iron(III) in natural water  

Microsoft Academic Search

An approach for speciation of iron (as Fe(II) and Fe(III)) based on integration of retention of the Fe(III)-SCN complex with detection using a conventional spectrophotometer is proposed here. The device (namely, a flow-cell packed with an exchange resin) has been coupled to a flow-injection manifold with inner-coupled injection valves which enables discrimination between Fe(III) and Fe(II) taking advantage of a

A. C. Lopes da Conceição; M. T. Tena; M. M. Correia dos Santos; M. L. Simões Gonçalves; M. D. Luque de Castro

1997-01-01

271

The World Beyond Iron  

NASA Astrophysics Data System (ADS)

The mere fact that the Mössbauer effect was discovered with the 129.4 keV transition in 191Ir demonstrates immediately the availability of Mössbauer isotopes other than 57Fe. Nevertheless, the 57Fe resonance remains the soul of Mössbauer spectroscopy. It combines a number of favorable properties: a source with convenient half-life (270 days), a large recoil-free fraction which allows measurements well above room temperature, and an energy resolution of ˜ 10 - 8 eV which is one to two orders of magnitude smaller than the typical hyperfine interaction energies. Yet, the energy resolution is not high enough to lead to substantial line broadenings by the unavoidable small distortions in the crystalline lattice of a real solid. The low natural abundance (2,2%) of the 57Fe is compensated by the large resonance cross-section and isotopic enrichment is only needed for materials containing iron in very low concentration or for extremely small samples. 57Fe was in fact not the second Mössbauer transition to be used after 191Ir. In establishing the correctness of the, not immediately believed, result of Mössbauer, the group at Argonne National Laboratory [1] measured not only the recoil-free resonance absorption in 191Ir, but also that of the 100 keV transition in 182W. This historically number two resonance has later mainly be used for the establishment of nuclear parameters.

Kalvius, G. Michael

272

Processing and trafficking of the iron regulatory protein, hemojuvelin.  

E-print Network

??Mutations in hemojuvelin (HJV) lead to the iron overload disorder juvenile hemochromatosis. HJV regulates iron metabolism by activating transcription of the iron regulatory peptide, hepcidin,… (more)

Maxson, Julia Elizabeth

2011-01-01

273

Integration and Integrity.  

ERIC Educational Resources Information Center

Explains two middle school teachers' cooperation with integrating regular and gifted students with disabled students. Focuses on disabled students' collaboration with their peers and their social skill development rather than their academic development. (YDS)

Cassano, Paul; Antol, Rayna A.

2001-01-01

274

Comparative Effects of Iron Deficiency Induced by Bleeding and a Low-Iron Diet on the Intestinal Absorptive Interactions of Iron, Cobalt, Manganese, Zinc, Lead and Cadmium1  

Microsoft Academic Search

Dietary iron deficiency enhances the absorption of iron, cobalt, manganese, zinc, cadmium and lead, whereas, iron deficiency due to bleeding in creases the absorption of iron, cobalt and perhaps manganese. To determine whether the response to bleeding is qualitatively different from that induced by dietary iron deficiency, metal absorption was studied in mice fed either a high- iron diet (120

PETER R. FLANAGAN; JAMES HAIST; LESLIE S. VALBERG

275

Synthesis and characterization of iron, iron oxide and iron carbide nanostructures  

NASA Astrophysics Data System (ADS)

Magnetic iron oxide (Fe3O4 and ?-Fe2O3) and iron carbide (Fe3C) nanoparticles of different geometrical shapes: cubes, spheres, rods and plates, have been prepared by thermal decomposition of a mixture containing the metal precursor Fe(CO)5 and the stabilizer polyvinylpyrrolidone (PVP) at 300 °C in a sealed cell under inert atmosphere. The thermal decomposition process was performed for 4 or 24 h at ([PVP]/[Fe(CO)5]) (w/v) ratio of 1:1 or 1:5. Elemental iron nanospheres embedded within a mixture of amorphous and graphitic carbon coating were obtained by hydrogen reduction of the prepared iron oxide and iron carbide nanoparticles at 450 °C. The formation of the graphitic carbon phase at such a low temperature is unique and probably obtained by catalysis of the elemental iron nanoparticles. Changing the annealing time period and the ([PVP]/[Fe(CO)5]) ratio allowed control of the composition, size, size distribution, crystallinity, geometrical shape and magnetic properties of the different magnetic nanoparticles.

Snovski, Ron; Grinblat, Judith; Sougrati, Moulay-Tahar; Jumas, Jean-Claude; Margel, Shlomo

2014-01-01

276

Iron Transport Systems in Neisseria meningitidis†  

PubMed Central

Acquisition of iron and iron complexes has long been recognized as a major determinant in the pathogenesis of Neisseria meningitidis. In this review, high-affinity iron uptake systems, which allow meningococci to utilize the human host proteins transferrin, lactoferrin, hemoglobin, and haptoglobin-hemoglobin as sources of essential iron, are described. Classic features of bacterial iron transport systems, such as regulation by the iron-responsive repressor Fur and TonB-dependent transport activity, are discussed, as well as more specific features of meningococcal iron transport. Our current understanding of how N. meningitidis acquires iron from the human host and the vaccine potentials of various components of these iron transport systems are also reviewed. PMID:15007100

Perkins-Balding, Donna; Ratliff-Griffin, Melanie; Stojiljkovic, Igor

2004-01-01

277

Cellular and mitochondrial iron homeostasis in vertebrates  

PubMed Central

Iron plays an essential role in cellular metabolism and biological processes. However, due to its intrinsic redox activity, free iron is a potentially toxic molecule in cellular biochemistry. Thus, organisms have developed sophisticated ways to import, sequester, and utilize iron. The transferrin cycle is a well-studied iron uptake pathway that is important for most vertebrate cells. Circulating iron can also be imported into cells by mechanisms that are independent of transferrin. Once imported into erythroid cells, iron is predominantly consumed by the mitochondria for the biosynthesis of heme and iron sulfur clusters. This review focuses on canonical transferrin-mediated and the newly discovered, non-transferrin mediated iron uptake pathways, as well as, mitochondrial iron homeostasis in higher eukaryotes. PMID:22285816

Chen, Caiyong; Paw, Barry H.

2012-01-01

278

Sequestration and Scavenging of Iron in Infection  

PubMed Central

The proliferative capability of many invasive pathogens is limited by the bioavailability of iron. Pathogens have thus developed strategies to obtain iron from their host organisms. In turn, host defense strategies have evolved to sequester iron from invasive pathogens. This review explores the mechanisms employed by bacterial pathogens to gain access to host iron sources, the role of iron in bacterial virulence, and iron-related genes required for the establishment or maintenance of infection. Host defenses to limit iron availability for bacterial growth during the acute-phase response and the consequences of iron overload conditions on susceptibility to bacterial infection are also examined. The evidence summarized herein demonstrates the importance of iron bioavailability in influencing the risk of infection and the ability of the host to clear the pathogen. PMID:23836822

Parrow, Nermi L.; Fleming, Robert E.

2013-01-01

279

Diagenesis of iron in modern marine sediments  

SciTech Connect

Rates of iron liberation to interstitial solution have been measured in vitro on sediments obtained from the rapidly depositing submarine portion of the Mississippi Delta, and from Long Island Sound. Rates were measured by inhibiting sulfate reduction (with molybdate) and following the build-up of dissolved iron with time. Both Mississippi Delta and Long Island Sound sediments show similar exponentially decreasing iron liberation rates with depth. It is found that rates of iron liberation are linearly related to rates of sulfate reduction, with the ratio of sulfide production/iron liberation equal to about 100. Unmodified Mississippi Delta sediment was incubated anoxically, and the behavior of dissolved Fe/sup +2/, SO/sub 4//sup -2/ and H/sub 2/S followed with time. A surprising result is that when abundant reactive iron minerals are present, rates of iron liberation are virtually the same in both the absence and presence of sulfate reduction. This means that for reactive Fe-rich sediments all H/sub 2/S liberated by sulfate reduction can be precipitated by reaction with detrital iron minerals to form iron sulfides so that relatively high concentrations of pore water iron can be observed in the presence of appreciable H/sub 2/S production. It also means that iron liberation to solution is most likely the result of bacterial iron reduction, and not the reduction of ferric oxides by dissolved sulfide. Diagenetic modeling of iron profiles using iron liberation rate measurements backs this contention.

Canfield, D.E.; Berner, R.A.

1985-01-01

280

Iron in food and its availability.  

PubMed

The iron stores of full-term, breast-fed infants become depleted by the age of 6 months, but this may occur earlier when they are fed formula that is not fortified with iron. There is a high requirement for iron, and therefore the selection of appropriate weaning foods is critical at this time. Continued consumption of breast milk or iron-fortified formulas until the age of one year will help maintain an adequate iron status, particularly in infants given diets of low iron availability. Many dietary constituents affect the availability of inorganic iron from foods, the most important ones in the case of the infant are ascorbic acid and haem iron, both of which enhance the absorption of inorganic iron. The majority of commercially-prepared infant foods contain added iron and ascorbic acid, thereby providing sufficient absorbable iron for the growing infant. On the other hand, the results of the few studies that have been carried out on infants suggest that many unfortified vegetable and cereal meals contain iron of low availability. This can, however, be increased by the simultaneous intake of fruit juices high in ascorbic acid. The recent advances made in stable isotope methodology should facilitate studies on iron absorption in infants, thereby leading to a better understanding of iron availability from foods. PMID:2485580

Fairweather-Tait, S J

1989-01-01

281

Iron coordination by catechol derivative antioxidants.  

PubMed

Iron complexes of nitrocatechols with different substituent groups [1: -CH = CR2; 2: -CH2-CHR2; 3: -CH = CR'(R")] were synthesized and their effects on iron-induced free radical reactions of biological importance investigated. Catechol and nitrocatechol derivatives effectively inhibited iron-induced lipid peroxide-dependent lipid peroxidation. In the Fenton-like reaction, iron-catechol generated hydroxyl radicals more strongly than did iron citrate, and iron-nitrocatechol derivative 2 generated a small amount of hydroxyl radicals. The iron complexes of derivatives 1 and 3 did not generate hydroxyl radicals. Iron-catechol had the highest ratio of reduction to oxidation rate constants and the second was iron-nitrocatechol 2, suggesting that iron chelated by nitrocatechols 1 and 3 may be most difficult to reduce. To elucidate the structure and physical properties of the iron complexes, UV/vis absorption spectroscopic, ESR and 1H NMR studies were performed in aqueous and DMSO solutions. In aqueous solution at pH 7.4, iron complexes of the nitrocatechol derivatives were high-spin tris(nitrocatecholato)ferrate(III) with a characteristic ligand-to-metal charge transfer absorbance (pi -> d pi). The lambda max of iron-nitrocatechol derivative 2 was shorter than those of iron-nitrocatechol derivatives 1 and 3, suggesting that the reduction potential of iron-nitrocatechol 2 is higher than that of iron-nitrocatechols 1 and 3. Nitrocatechol derivatives with a conjugation structure can sequester the chelated iron more effectively than catechol and the derivative without the conjugation against free radical generation by keeping the iron in the ferric state, probably because of the reduction potentials. PMID:8630099

Kawabata, T; Schepkin, V; Haramaki, N; Phadke, R S; Packer, L

1996-06-14

282

Salmonella Adhesion, Invasion and Cellular Immune Responses Are Differentially Affected by Iron Concentrations in a Combined In Vitro Gut Fermentation-Cell Model  

PubMed Central

In regions with a high infectious disease burden, concerns have been raised about the safety of iron supplementation because higher iron concentrations in the gut lumen may increase risk of enteropathogen infection. The aim of this study was to investigate interactions of the enteropathogen Salmonella enterica ssp. enterica Typhimurium with intestinal cells under different iron concentrations encountered in the gut lumen during iron deficiency and supplementation using an in vitro colonic fermentation system inoculated with immobilized child gut microbiota combined with Caco-2/HT29-MTX co-culture monolayers. Colonic fermentation effluents obtained during normal, low (chelation by 2,2'-dipyridyl) and high iron (26.5 mg iron/L) fermentation conditions containing Salmonella or pure Salmonella cultures with similar iron conditions were applied to cellular monolayers. Salmonella adhesion and invasion capacity, cellular integrity and immune response were assessed. Under high iron conditions in pure culture, Salmonella adhesion was 8-fold increased compared to normal iron conditions while invasion was not affected leading to decreased invasion efficiency (?86%). Moreover, cellular cytokines IL-1?, IL-6, IL-8 and TNF-? secretion as well as NF-?B activation in THP-1 cells were attenuated under high iron conditions. Low iron conditions in pure culture increased Salmonella invasion correlating with an increase in IL-8 release. In fermentation effluents, Salmonella adhesion was 12-fold and invasion was 428-fold reduced compared to pure culture. Salmonella in high iron fermentation effluents had decreased invasion efficiency (?77.1%) and cellular TNF-? release compared to normal iron effluent. The presence of commensal microbiota and bacterial metabolites in fermentation effluents reduced adhesion and invasion of Salmonella compared to pure culture highlighting the importance of the gut microbiota as a barrier during pathogen invasion. High iron concentrations as encountered in the gut lumen during iron supplementation attenuated Salmonella invasion efficiency and cellular immune response suggesting that high iron concentrations alone may not lead to an increased Salmonella invasion. PMID:24676135

Dostal, Alexandra; Gagnon, Mélanie; Chassard, Christophe; Zimmermann, Michael Bruce; O'Mahony, Liam; Lacroix, Christophe

2014-01-01

283

Salmonella adhesion, invasion and cellular immune responses are differentially affected by iron concentrations in a combined in vitro gut fermentation-cell model.  

PubMed

In regions with a high infectious disease burden, concerns have been raised about the safety of iron supplementation because higher iron concentrations in the gut lumen may increase risk of enteropathogen infection. The aim of this study was to investigate interactions of the enteropathogen Salmonella enterica ssp. enterica Typhimurium with intestinal cells under different iron concentrations encountered in the gut lumen during iron deficiency and supplementation using an in vitro colonic fermentation system inoculated with immobilized child gut microbiota combined with Caco-2/HT29-MTX co-culture monolayers. Colonic fermentation effluents obtained during normal, low (chelation by 2,2'-dipyridyl) and high iron (26.5 mg iron/L) fermentation conditions containing Salmonella or pure Salmonella cultures with similar iron conditions were applied to cellular monolayers. Salmonella adhesion and invasion capacity, cellular integrity and immune response were assessed. Under high iron conditions in pure culture, Salmonella adhesion was 8-fold increased compared to normal iron conditions while invasion was not affected leading to decreased invasion efficiency (-86%). Moreover, cellular cytokines IL-1?, IL-6, IL-8 and TNF-? secretion as well as NF-?B activation in THP-1 cells were attenuated under high iron conditions. Low iron conditions in pure culture increased Salmonella invasion correlating with an increase in IL-8 release. In fermentation effluents, Salmonella adhesion was 12-fold and invasion was 428-fold reduced compared to pure culture. Salmonella in high iron fermentation effluents had decreased invasion efficiency (-77.1%) and cellular TNF-? release compared to normal iron effluent. The presence of commensal microbiota and bacterial metabolites in fermentation effluents reduced adhesion and invasion of Salmonella compared to pure culture highlighting the importance of the gut microbiota as a barrier during pathogen invasion. High iron concentrations as encountered in the gut lumen during iron supplementation attenuated Salmonella invasion efficiency and cellular immune response suggesting that high iron concentrations alone may not lead to an increased Salmonella invasion. PMID:24676135

Dostal, Alexandra; Gagnon, Mélanie; Chassard, Christophe; Zimmermann, Michael Bruce; O'Mahony, Liam; Lacroix, Christophe

2014-01-01

284

Laboratory experiments on the weathering of iron meteorites and carbonaceous chondrites by iron-oxidizing bacteria  

NASA Astrophysics Data System (ADS)

Batch culture experiments were performed to investigate the weathering of meteoritic material by iron-oxidizing bacteria. The aerobic, acidophilic iron oxidizer (A. ferrooxidans) was capable of oxidizing iron from both carbonaceous chondrites (Murchison and Cold Bokkeveld) and iron meteorites (York and Casas Grandes). Preliminary iron isotope results clearly show contrasted iron pathways during oxidation with and without bacteria suggesting that a biological role in meteorite weathering could be distinguished isotopically. Anaerobic iron-oxidizers growing under pH-neutral conditions oxidized iron from iron meteorites. These results show that rapid biologicallymediated alteration of extraterrestrial materials can occur in both aerobic and anaerobic environments. These results also demonstrate that iron can act as a source of energy for microorganisms from both iron and carbonaceous chondrites in aerobic and anaerobic conditions with implications for life on the early Earth and the possible use of microorganisms to extract minerals from asteroidal material.

Gronstal, A.; Pearson, V.; Kappler, A.; Dooris, C.; Anand, M.; Poitrasson, F.; Kee, T. P.; Cockell, C. S.

2009-03-01

285

Sonochemical synthesis of iron colloids  

SciTech Connect

We present here a new method for the preparation of stable ferromagnetic colloids of iron using high-intensity ultrasound to sonochemically decompose volatile organometallic compounds. These colloids have narrow size distributions centered at a few nanometers and are found to be superparamagnetic. In conclusion, a simple synthetic method has been discovered to produce nanosized iron colloid using high-intensity ultrasound. Nanometer iron particles dispersed in polyvinylpyrrolidone (PVP) matrix or stabilized by adsorption of oleic acid have been synthesized by sonochemical decomposition of Fe(CO){sub 5}. Transmission electron micrographs show that the iron particles have a relatively narrow range in size from 3 to 8 nm for polyvinylpyrrolidone, while oleic acid gives an even more uniform distribution at 8 nm. magnetic measurements revealed that these nanometer iron particles are superparamagnetic with a saturation magnetization of 101 emu/g (Fe) at 290 K. This work is easily extended to colloids of other metals and to alloys of two or more metals, simply by using multiple volatile precursors. 29 refs., 4 figs.

Suslick, K.S.; Fang, M.; Hyeon, T. [Univ. of Illinois, Urbana, IL (United States)] [Univ. of Illinois, Urbana, IL (United States)

1996-11-27

286

Direct Biohydrometallurgical Extraction of Iron from Ore  

SciTech Connect

A completely novel approach to iron extraction was investigated, based on reductive leaching of iron by anaerobic bacteria. Microorganisms were collected from an anaerobic bog where natural seepage of dissolved iron was observed. This mixed culture was used to reduce insoluble iron in a magnetite ore to the soluble ferrous (Fe{sup +2}) state. While dissolution rates were slow, concentrations of dissolved iron as high as 3487 mg/l could be reached if sufficient time was allowed. A factorial study of the effects of trace nutrients and different forms of organic matter indicated that the best dissolution rates and highest dissolved iron concentrations were achieved using soluble carbohydrate (sucrose) as the bacterial food source, and that nutrients other than nitrogen, phosphorus, potassium, sodium, and acetate were not necessary. A key factor in reaching high levels of dissolved iron was maintaining a high level of carbon dioxide in solution, since the solubility of iron carbonates increases markedly as the quantity of dissolved carbon dioxide increases. Once the iron is dissolved, it has been demonstrated that the ferrous iron can then be electroplated from solution, provided that the concentration of iron is sufficiently high and the hydrogen ion concentration is sufficiently low. However, if the leaching solution is electrolyzed directly, organic matter precipitates at the cathode along with the metallic iron. To prevent this problem, the ferrous iron should be separated from the bulk solution in a more concentrated, purified form. One route to accomplishing this is to take advantage of the change in solubility of ferrous iron as a function of carbon dioxide concentration. By cycling the concentration of carbon dioxide in solution, it is possible to produce an iron-rich concentrate that should be suitable for electrolysis. This represents the first viable hydrometallurgical method for leaching iron directly from ore and producing metallic iron.

T.C. Eisele

2005-10-01

287

Iron homeostasis and toxicity in retinal degeneration  

PubMed Central

Iron is essential for many metabolic processes but can also cause damage. As a potent generator of hydroxyl radical, the most reactive of the free radicals, iron can cause considerable oxidative stress. Since iron is absorbed through diet but not excreted except through menstruation, total body iron levels build up with age. Macular iron levels increase with age, in both men and women. This iron has the potential to contribute to retinal degeneration. Here we present an overview of the evidence suggesting that iron may contribute to retinal degenerations. Intraocular iron foreign bodies cause retinal degeneration. Retinal iron buildup resulting from hereditary iron homeostasis disorders aceruloplasminemia, Friedreich’s Ataxia, and panthothenate kinase associated neurodegeneration cause retinal degeneration. Mice with targeted mutation of the iron exporter ceruloplasmin have age-dependent retinal iron overload and a resulting retinal degeneration with features of age-related macular degeneration (AMD). Post mortem retinas from patients with AMD have more iron and the iron carrier transferrin than age- matched controls. Over the past ten years much has been learned about the intricate network of proteins involved in iron handling. Many of these, including transferrin, transferrin receptor, divalent metal transporter 1, ferritin, ferroportin, ceruloplasmin, hephaestin, iron regulatory protein, and histocompatibility leukocyte antigen class I-like protein involved in iron homeostasis (HFE) have been found in the retina. Some of these proteins have been found in the cornea and lens as well. Levels of the iron carrier transferrin are high in the aqueous and vitreous humors. The functions of these proteins in other tissues, combined with studies on cultured ocular tissues, genetically engineered mice, and eye exams on patients with hereditary iron diseases provide clues regarding their ocular functions. Iron may play a role in a broad range of ocular diseases, including glaucoma, cataract, AMD, and conditions causing intraocular hemorrhage. While iron deficiency must be prevented, the therapeutic potential of limiting iron induced ocular oxidative damage is high. Systemic, local, or topical iron chelation with an expanding repertoire of drugs has clinical potential. PMID:17921041

He, Xining; Hahn, Paul; Iacovelli, Jared; Wong, Robert; King, Chih; Bhisitkul, Robert; Massaro-Giordano, Mina; Dunaief, Joshua L.

2007-01-01

288

Iron, lactoferrin and iron regulatory protein activity in the synovium; relative importance of iron loading and the inflammatory response  

Microsoft Academic Search

OBJECTIVESTo determine the ability of lactoferrin in rheumatoid arthritis (RA) synovial fluid to bind “free” iron, and to study the regulatory mechanisms therein that control iron homeostasis.METHODS“Free” iron was determined by the bleomycin assay and lactoferrin concentrations by enzyme linked immunosorbent assay. The activities of iron regulatory protein (IRP) and NF-?B in synovial fluid cells were assayed by mobility shift

C Guillén; I B McInnes; H Kruger; J H Brock

1998-01-01

289

Estimation of Dietary Iron Bioavailability from Food Iron Intake and Iron Status  

PubMed Central

Currently there are no satisfactory methods for estimating dietary iron absorption (bioavailability) at a population level, but this is essential for deriving dietary reference values using the factorial approach. The aim of this work was to develop a novel approach for estimating dietary iron absorption using a population sample from a sub-section of the UK National Diet and Nutrition Survey (NDNS). Data were analyzed in 873 subjects from the 2000–2001 adult cohort of the NDNS, for whom both dietary intake data and hematological measures (hemoglobin and serum ferritin (SF) concentrations) were available. There were 495 men aged 19–64 y (mean age 42.7±12.1 y) and 378 pre-menopausal women (mean age 35.7±8.2 y). Individual dietary iron requirements were estimated using the Institute of Medicine calculations. A full probability approach was then applied to estimate the prevalence of dietary intakes that were insufficient to meet the needs of the men and women separately, based on their estimated daily iron intake and a series of absorption values ranging from 1–40%. The prevalence of SF concentrations below selected cut-off values (indicating that absorption was not high enough to maintain iron stores) was derived from individual SF concentrations. An estimate of dietary iron absorption required to maintain specified SF values was then calculated by matching the observed prevalence of insufficiency with the prevalence predicted for the series of absorption estimates. Mean daily dietary iron intakes were 13.5 mg for men and 9.8 mg for women. Mean calculated dietary absorption was 8% in men (50th percentile for SF 85 µg/L) and 17% in women (50th percentile for SF 38 µg/L). At a ferritin level of 45 µg/L estimated absorption was similar in men (14%) and women (13%). This new method can be used to calculate dietary iron absorption at a population level using data describing total iron intake and SF concentration. PMID:25356629

Dainty, Jack R.; Berry, Rachel; Lynch, Sean R.; Harvey, Linda J.; Fairweather-Tait, Susan J.

2014-01-01

290

Iron chelation and multiple sclerosis.  

PubMed

Histochemical and MRI studies have demonstrated that MS (multiple sclerosis) patients have abnormal deposition of iron in both gray and white matter structures. Data is emerging indicating that this iron could partake in pathogenesis by various mechanisms, e.g., promoting the production of reactive oxygen species and enhancing the production of proinflammatory cytokines. Iron chelation therapy could be a viable strategy to block iron-related pathological events or it can confer cellular protection by stabilizing hypoxia inducible factor 1?, a transcription factor that normally responds to hypoxic conditions. Iron chelation has been shown to protect against disease progression and/or limit iron accumulation in some neurological disorders or their experimental models. Data from studies that administered a chelator to animals with experimental autoimmune encephalomyelitis, a model of MS, support the rationale for examining this treatment approach in MS. Preliminary clinical studies have been performed in MS patients using deferoxamine. Although some side effects were observed, the large majority of patients were able to tolerate the arduous administration regimen, i.e., 6-8 h of subcutaneous infusion, and all side effects resolved upon discontinuation of treatment. Importantly, these preliminary studies did not identify a disqualifying event for this experimental approach. More recently developed chelators, deferasirox and deferiprone, are more desirable for possible use in MS given their oral administration, and importantly, deferiprone can cross the blood-brain barrier. However, experiences from other conditions indicate that the potential for adverse events during chelation therapy necessitates close patient monitoring and a carefully considered administration regimen. PMID:24397846

Weigel, Kelsey J; Lynch, Sharon G; LeVine, Steven M

2014-01-01

291

Disassembling iron availability to phytoplankton.  

PubMed

The bioavailability of iron to microorganisms and its underlying mechanisms have far reaching repercussions to many natural systems and diverse fields of research, including ocean biogeochemistry, carbon cycling and climate, harmful algal blooms, soil and plant research, bioremediation, pathogenesis, and medicine. Within the framework of ocean sciences, short supply and restricted bioavailability of Fe to phytoplankton is thought to limit primary production and curtail atmospheric CO(2) drawdown in vast ocean regions. Yet a clear-cut definition of bioavailability remains elusive, with elements of iron speciation and kinetics, phytoplankton physiology, light, temperature, and microbial interactions, to name a few, all intricately intertwined into this concept. Here, in a synthesis of published and new data, we attempt to disassemble the complex concept of iron bioavailability to phytoplankton by individually exploring some of its facets. We distinguish between the fundamentals of bioavailability - the acquisition of Fe-substrate by phytoplankton - and added levels of complexity involving interactions among organisms, iron, and ecosystem processes. We first examine how phytoplankton acquire free and organically bound iron, drawing attention to the pervasiveness of the reductive uptake pathway in both prokaryotic and eukaryotic autotrophs. Turning to acquisition rates, we propose to view the availability of various Fe-substrates to phytoplankton as a spectrum rather than an absolute "all or nothing." We then demonstrate the use of uptake rate constants to make comparisons across different studies, organisms, Fe-compounds, and environments, and for gaging the contribution of various Fe-substrates to phytoplankton growth in situ. Last, we describe the influence of aquatic microorganisms on iron chemistry and fate by way of organic complexation and bio-mediated redox transformations and examine the bioavailability of these bio-modified Fe species. PMID:22529839

Shaked, Yeala; Lis, Hagar

2012-01-01

292

Acetaminophen Protects Against Iron-Induced Cardiac Damage in Gerbils  

Microsoft Academic Search

Th ere are few eff ective agents that safely remove excess iron from iron-overloaded individuals. Our goal was to evaluate the iron-removing eff ectiveness of acetaminophen given ip or orally in the gerbil iron-overload model. Male gerbils were divided into 5 groups: saline controls, iron-overloaded controls, iron-overloaded treated with ip acetaminophen, iron-overloaded treated with oral acetaminophen, and iron-overloaded treated with

Ernest M. Walker; Christopher P. Epling; Cordel Parris; Silvestre Cansino; Protip Ghosh; Devashish H. Desai; Ryan G. Morrison; Gary L. Wright; Paulette Wehner; Elsa I. Mangiarua; Sandra M. Walker; Eric R. Blough

293

Speciation of iron in the aquatic environment.  

PubMed

Iron is one of the basic metals occurring in the aquatic environment and it is considered a macroelement with regard to live organisms. This metal has a broad range of applications that, together with factors conditioning its chemical transitions, results in the occurrence of many iron species in water. Depending on water and land development type, as well as the use of water for household and industrial purposes, iron may be found in different forms, including solutions, colloids or suspensions, made up by both simple ions or particles and complex organic or inorganic compounds. Due to changing properties of the different iron forms and their varying influence, it is critical to gain information about its speciation. In this article we present information about iron species, including nano-iron forms, in various aquatic environments (i.e., marshland, ocean waters) as well as the exemplary methods for separating iron from iron-containing environmental samples. PMID:25306789

Rabajczyk, Anna; Namie?nik, Jacek

2014-08-01

294

Iron availability from infant food supplements.  

PubMed

Radioiron absorption tests are performed in human volunteer subjects to measure iron absorption from five infant food supplements. These products included corn-soya-milk, corn-soy blend, wheat-soy blend, wheat protein concentrate blend, and whey-soy drink mix. In iron replete adult males, mean percentage absorption ranged from 0.6 to 1.4%. By relating these results to absorption from a reference dose of inorganic iron, it was estimated that iron-deficient infants would absorb between 1.7 and 4.1% of the iron contained in the infant foods. These results indicate that this fortification iron is poorly absorbed, and probably supplies only about half of the daily iron requirement for iron deficient children between 6 months and 3 yr of age. PMID:7198375

Morck, T A; Lynch, S R; Skikne, B S; Cook, J D

1981-12-01

295

Mechanisms of iron metabolism in Caenorhabditis elegans  

PubMed Central

Iron is involved in many biological processes essential for sustaining life. In excess, iron is toxic due to its ability to catalyze the formation of free radicals that damage macromolecules. Organisms have developed specialized mechanisms to tightly regulate iron uptake, storage and efflux. Over the past decades, vertebrate model organisms have led to the identification of key genes and pathways that regulate systemic and cellular iron metabolism. This review provides an overview of iron metabolism in the roundworm Caenorhabditis elegans and highlights recent studies on the role of hypoxia and insulin signaling in the regulation of iron metabolism. Given that iron, hypoxia and insulin signaling pathways are evolutionarily conserved, C. elegans provides a genetic model organism that promises to provide new insights into mechanisms regulating mammalian iron metabolism. PMID:24904417

Anderson, Cole P.; Leibold, Elizabeth A.

2014-01-01

296

Molecular Mediators Governing Iron-Copper Interactions  

PubMed Central

Given their similar physiochemical properties, it is a logical postulate that iron and copper metabolism are intertwined. Indeed, iron-copper interactions were first documented over a century ago, but the homeostatic effects of one on the other has not been elucidated at a molecular level to date. Recent experimental work has, however, begun to provide mechanistic insight into how copper influences iron metabolism. During iron deficiency, elevated copper levels are observed in the intestinal mucosa, liver, and blood. Copper accumulation and/or redistribution within enterocytes may influence iron transport, and high hepatic copper may enhance biosynthesis of a circulating ferroxidase, which potentiates iron release from stores. Moreover, emerging evidence has documented direct effects of copper on the expression and activity of the iron-regulatory hormone hepcidin. This review summarizes current experimental work in this field, with a focus on molecular aspects of iron-copper interplay and how these interactions relate to various disease states. PMID:24995690

Gulec, Sukru; Collins, James F.

2015-01-01

297

21 CFR 582.5375 - Iron reduced.  

... ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5375 Iron reduced. (a) Product. Iron reduced. (b) Conditions of use. This...

2014-04-01

298

49 CFR 192.487 - Remedial measures: Distribution lines other than cast iron or ductile iron lines.  

Code of Federal Regulations, 2012 CFR

...Remedial measures: Distribution lines other than cast iron or ductile iron lines. 192.487 Section 192.487 Transportation...Remedial measures: Distribution lines other than cast iron or ductile iron lines. (a) General...

2012-10-01

299

49 CFR 192.487 - Remedial measures: Distribution lines other than cast iron or ductile iron lines.  

Code of Federal Regulations, 2011 CFR

...Remedial measures: Distribution lines other than cast iron or ductile iron lines. 192.487 Section 192.487 Transportation...Remedial measures: Distribution lines other than cast iron or ductile iron lines. (a) General...

2011-10-01

300

49 CFR 192.487 - Remedial measures: Distribution lines other than cast iron or ductile iron lines.  

Code of Federal Regulations, 2013 CFR

...Remedial measures: Distribution lines other than cast iron or ductile iron lines. 192.487 Section 192.487 Transportation...Remedial measures: Distribution lines other than cast iron or ductile iron lines. (a) General...

2013-10-01

301

49 CFR 192.487 - Remedial measures: Distribution lines other than cast iron or ductile iron lines.  

Code of Federal Regulations, 2010 CFR

...Remedial measures: Distribution lines other than cast iron or ductile iron lines. 192.487 Section 192.487 Transportation...Remedial measures: Distribution lines other than cast iron or ductile iron lines. (a) General...

2010-10-01

302

DOMAIN PATTERNS AND REVERSALS BY WALL MOVEMENTS OF THIN FILMS OF IRON AND NICKEL IRON  

E-print Network

310 DOMAIN PATTERNS AND REVERSALS BY WALL MOVEMENTS OF THIN FILMS OF IRON AND NICKEL IRON By C. E in which a magnetic field was applied during evaporation. The behaviour of the iron film is similar in both directions but in the case of the nickel-iron film the reversal of magnetization in the perpendicular

Paris-Sud XI, Université de

303

Increased iron (III) and total iron content in post mortem substantia nigra of parkinsonian brain  

Microsoft Academic Search

Summary Significant differences in the content of iron (III) and total iron were found in post mortem substantia nigra of Parkinson's disease. There was an increase of 176% in the levels of total iron and 255% of iron (III) in the substantia nigra of the parkinsonian patients compared to age matched controls. In the cortex (Brodmann area 21), hippocampus, putamen,

E. Sofic; P. Riederer; H. Heinsen; H. Beckmann; G. P. Reynolds; G. Hebenstreit; M. B. H. Youdim

1988-01-01

304

Fep1, an Iron Sensor Regulating Iron Transporter Gene Expression in Schizosaccharomyces pombe*  

E-print Network

Fep1, an Iron Sensor Regulating Iron Transporter Gene Expression in Schizosaccharomyces pombe iron under high affinity conditions through the action of a cell sur- face ferric reductase encoded by the frp1 gene and a two-component iron-transporting complex encoded by the fip1 and fio1 genes. When cells

Labbé, Simon

305

Role of microbial iron reduction in the dissolution of iron hydroxysulfate minerals  

E-print Network

jarosite and schwertmannite at neutral pH by iron-reducing bacteria. Mineral dissolution was tested usingRole of microbial iron reduction in the dissolution of iron hydroxysulfate minerals Elizabeth J. P in mineral dissolution, releasing these bound contaminants. Reduction of structural sulfate in the iron

306

Ironing Out the Wrinkles in Host Defense: Interactions between Iron Homeostasis and Innate Immunity  

Microsoft Academic Search

Iron is an essential micronutrient for both microbial pathogens and their mammalian hosts. Changes in iron availability and distribution have significant effects on pathogen virulence and on the immune response to infection. Recent advances in our understanding of the molecular regulation of iron metabolism have shed new light on how alterations in iron homeostasis both contribute to and influence innate

Lijian Wang; Bobby J. Cherayil

2009-01-01

307

Interrelationships between tissue iron status and erythropoiesis during postweaning development following neonatal iron deficiency in rats  

PubMed Central

Dietary iron is particularly critical during periods of rapid growth such as in neonatal development. Human and rodent studies have indicated that iron deficiency or excess during this critical stage of development can have significant long- and short-term consequences. Since the requirement for iron changes during development, the availability of adequate iron is critical for the differentiation and maturation of individual organs participating in iron homeostasis. We have examined in rats the effects of dietary iron supplement following neonatal iron deficiency on tissue iron status in relation to erythropoietic ability during 16 wk of postweaning development. This physiological model indicates that postweaning iron-adequate diet following neonatal iron deficiency adversely affects erythroid differentiation in the bone marrow and promotes splenic erythropoiesis leading to splenomegaly and erythrocytosis. This altered physiology of iron homeostasis during postweaning development is also reflected in the inability to maintain liver and spleen iron concentrations and the altered expression of iron regulatory proteins in the liver. These studies provide critical insights into the consequences of neonatal iron deficiency and the dietary iron-induced cellular signals affecting iron homeostasis during early development. PMID:21193529

Unger, Erica L.; Jensen, Gordon L.; Hankey, Pamela A.; Paulson, Robert F.

2011-01-01

308

Controlling iron availability to phytoplankton in iron-replete coastal waters  

Microsoft Academic Search

Recent work demonstrates that the micronutrient iron may strongly influence the magnitude and character of algal production in nearshore waters due in part to the higher but variable iron requirements of neritic phytoplankton. However, ascertaining the direct effects of iron nutrition in coastal waters has been forestalled by our inability to experimentally regulate ambient iron availability independent of other factors.

Mark L. Wells; Charles G. Trick

2004-01-01

309

Intestinal HIF2? promotes tissue-iron accumulation in disorders of iron overload with anemia  

PubMed Central

Several distinct congenital disorders can lead to tissue-iron overload with anemia. Repeated blood transfusions are one of the major causes of iron overload in several of these disorders, including ?-thalassemia major, which is characterized by a defective ?-globin gene. In this state, hyperabsorption of iron is also observed and can significantly contribute to iron overload. In ?-thalassemia intermedia, which does not require blood transfusion for survival, hyperabsorption of iron is the leading cause of iron overload. The mechanism of increased iron absorption in ?-thalassemia is unclear. We definitively demonstrate, using genetic mouse models, that intestinal hypoxia-inducible factor-2? (HIF2?) and divalent metal transporter-1 (DMT1) are activated early in the pathogenesis of ?-thalassemia and are essential for excess iron accumulation in mouse models of ?-thalassemia. Moreover, thalassemic mice with established iron overload had significant improvement in tissue-iron levels and anemia following disruption of intestinal HIF2?. In addition to repeated blood transfusions and increased iron absorption, chronic hemolysis is the major cause of tissue-iron accumulation in anemic iron-overload disorders caused by hemolytic anemia. Mechanistic studies in a hemolytic anemia mouse model demonstrated that loss of intestinal HIF2?/DMT1 signaling led to decreased tissue-iron accumulation in the liver without worsening the anemia. These data demonstrate that dysregulation of intestinal hypoxia and HIF2? signaling is critical for progressive iron overload in ?-thalassemia and may be a novel therapeutic target in several anemic iron-overload disorders. PMID:24282296

Anderson, Erik R.; Taylor, Matthew; Xue, Xiang; Ramakrishnan, Sadeesh K.; Martin, Angelical; Xie, Liwei; Bredell, Bryce X.; Gardenghi, Sara; Rivella, Stefano; Shah, Yatrik M.

2013-01-01

310

Intestinal HIF2? promotes tissue-iron accumulation in disorders of iron overload with anemia.  

PubMed

Several distinct congenital disorders can lead to tissue-iron overload with anemia. Repeated blood transfusions are one of the major causes of iron overload in several of these disorders, including ?-thalassemia major, which is characterized by a defective ?-globin gene. In this state, hyperabsorption of iron is also observed and can significantly contribute to iron overload. In ?-thalassemia intermedia, which does not require blood transfusion for survival, hyperabsorption of iron is the leading cause of iron overload. The mechanism of increased iron absorption in ?-thalassemia is unclear. We definitively demonstrate, using genetic mouse models, that intestinal hypoxia-inducible factor-2? (HIF2?) and divalent metal transporter-1 (DMT1) are activated early in the pathogenesis of ?-thalassemia and are essential for excess iron accumulation in mouse models of ?-thalassemia. Moreover, thalassemic mice with established iron overload had significant improvement in tissue-iron levels and anemia following disruption of intestinal HIF2?. In addition to repeated blood transfusions and increased iron absorption, chronic hemolysis is the major cause of tissue-iron accumulation in anemic iron-overload disorders caused by hemolytic anemia. Mechanistic studies in a hemolytic anemia mouse model demonstrated that loss of intestinal HIF2?/DMT1 signaling led to decreased tissue-iron accumulation in the liver without worsening the anemia. These data demonstrate that dysregulation of intestinal hypoxia and HIF2? signaling is critical for progressive iron overload in ?-thalassemia and may be a novel therapeutic target in several anemic iron-overload disorders. PMID:24282296

Anderson, Erik R; Taylor, Matthew; Xue, Xiang; Ramakrishnan, Sadeesh K; Martin, Angelical; Xie, Liwei; Bredell, Bryce X; Gardenghi, Sara; Rivella, Stefano; Shah, Yatrik M

2013-12-10

311

Desferrioxamine-mediated Iron Uptake in Saccharomyces cerevisiae EVIDENCE FOR TWO PATHWAYS OF IRON UPTAKE*  

E-print Network

Desferrioxamine-mediated Iron Uptake in Saccharomyces cerevisiae EVIDENCE FOR TWO PATHWAYS OF IRON Medical Institute, Stanford, California 94305-5428 In the yeast Saccharomyces cerevisiae, uptake of iron is largely regulated by the transcription factor Aft1. cDNA microarrays were used to identify new iron

Botstein, David

312

Microporation and ‘Iron’ tophoresis for treating Iron deficiency anemia  

PubMed Central

Purpose Iontophoretic mediated transdermal delivery of ferric pyrophosphate (FPP) in combination with microneedle pretreatment was investigated as a potential treatment for iron deficiency anemia (IDA). Methods In vitro transdermal delivery studies were performed using hairless rat skin and pharmacodynamic studies were performed in hairless anemic rat model. The hematological and biochemical parameters like hemoglobin, hematocrit and % serum transferrin were monitored in rats at healthy, anemic condition and post treatment. Micropores created by the microneedles were visualized in histological skin sections after staining with hemotoxylin and eosin. The recovery of micropores was investigated in vivo by measuring Transepidermal water loss (TEWL) at different time points. Results The passive, microneedle and iontophoresis mediated delivery did not lead to significant improvement in hematological and biochemical parameters in anemic rats, when used individually. When iontophoresis (0.15 mA/cm2 for 4 hours) was combined with microneedle pretreatment (for 2 minutes), therapeutically adequate amount of FPP was delivered and there was significant recovery of rats from IDA. Conclusions Microneedle and iontophoresis mediated delivery of iron via transdermal route could be developed as a potential treatment for IDA. The transdermal controlled delivery of iron could become a potential, safe and effective alternative to parenteral iron therapy. PMID:23187864

Modepalli, Naresh; Jo, Seongbong; Repka, Michael A.; Murthy, S. Narasimha

2012-01-01

313

What is new in iron overload?  

Microsoft Academic Search

Children with severe chronic hemolytic anemia or congenital erythroblastopenia are transfusion dependent. Long-term transfusion\\u000a therapy prolongs life but results in a toxic accumulation of iron in the organs. The human body cannot actively eliminate\\u000a excess iron. Therefore, the use of a chelating agent is required to promote excretion of iron. So far, iron chelation has\\u000a been done by subcutaneous infusion

Christiane Vermylen

2008-01-01

314

Intravenous iron-containing products: EMA procrastination.  

PubMed

A European reassessment has led to identical changes in the summaries of product characteristics (SPCs) for all intravenous iron-containing products: the risk of serious adverse effects is now highlighted, underlining the fact that intravenous iron-containing products should only be used when the benefits clearly outweigh the harms. Unfortunately, iron dextran still remains on the market despite a higher risk of hypersensitivity reactions than with iron sucrose. PMID:25162093

2014-07-01

315

Iron deficiency anaemia in Nigerian pregnant women.  

PubMed

Ninety-four Nigerian pregnant women, many of who had mild to moderate anaemia, were investigated for the presence of iron deficiency. Using the bone marrow as the diagnostic index, 90% of these patients were found to be iron deficient. Iron deficiency is thus common among our expectant mothers. They should, therefore, be given iron supplement in addition to the present practice of folic acid and antimalarials, throughout pregnancy and the puerperium. PMID:15899

Ogunbode, O; Oluboyede, O A

1976-01-01

316

Iron chaperones for mitochondrial Fe–S cluster biosynthesis and ferritin iron storage  

PubMed Central

Protein controlled iron homeostasis is essential for maintaining appropriate levels and availability of metal within cells. Recently, two iron chaperones have been discovered that direct metal within two unique pathways: (1) mitochondrial iron–sulfur (Fe–S) cluster assembly and (2) within the ferritin iron storage system. Although structural and functional details describing how these iron chaperones operate are emerging, both share similar iron binding affinities and metal–ligand site structures that enable them to bind and release Fe2+ to specific protein partners. Molecular details related to iron binding and delivery by these chaperones will be explored within this review. PMID:21288761

Subramanian, Poorna; Rodrigues, Andria V; Ghimire-Rijal, Sudipa; Stemmler, Timothy L

2012-01-01

317

Effects of High Dietary HEME Iron and Radiation on Cardiovascular Function  

NASA Technical Reports Server (NTRS)

The radiation related health risks to astronauts is of particular concern to NASA. Data support that exposure to radiation is associated with a number of disorders including a heightened risk for cardiovascular diseases. Independent of radiation, altered nutrient status (e.g. high dietary iron) also increases ones risk for cardiovascular disease. However, it is unknown whether exposure to radiation in combination with high dietary iron further increases ones cardiovascular risk. The intent of our proposal is to generate compulsory data examining the combined effect of radiation exposure and iron overload on sensitivity to radiation injury to address HRP risks: 1) Risk Factor of Inadequate Nutrition; 2) Risk of Cardiac Rhythm Problems; and 3) Risk of Degenerative Tissue or other Health Effects from Space Radiation. Towards our goal we propose two distinct pilot studies using the following specific aims: Vascular Aim 1: To determine the short-term consequences of the independent and combined effects of exposure to gamma radiation and elevated body iron stores on measures of endothelial function and cell viability and integrity. We hypothesize that animals that have high body iron stores and are exposed to gamma radiation will show a greater reduction in endothelial dependent nitric oxid production and larger pathological changes in endothelial integrity than animals that have only 1 of those treatments (either high iron stores or exposure to gamma radiation). Vascular Aim 2: Identify and compare the effects of gamma radiation and elevated body iron stores on the genetic and epigenetic regulation of proteins associated with endothelial cell function. We hypothesize that modifications of epigenetic control and posttranslational expression of proteins associated with endothelial cell function will be differentially altered in rats with high body iron stores and exposed to gamma radiation compared to rats with only 1 type of treatment. Cardiac Aim 1: To determine the short-term consequences of the independent and combined effects of gamma radiation and elevated body iron stores on measures of cardiac structure. We hypothesize that modifications to cardiac structure and function will be greater in rats with high body iron stores and exposed to gamma radiation than in rats that have only 1 of those treatments. Cardiac Aim 2: Identify and compare the effects of gamma radiation and elevated body iron stores on the genetic and epigenetic regulation of proteins associated with cardiac structure and function. We hypothesize that modifications of epigenetic control and posttranslational expression of proteins associated with cardiac contractile function will be differentially altered in rats with high body iron stores and exposed to gamma radiation compared to rats with only 1 type of treatment.

Westby, Christian M.; Brown, A. K.; Platts, S. H.

2012-01-01

318

Microbial iron uptake as a mechanism for dispersing iron from deep-sea hydrothermal vents.  

PubMed

Deep-sea hydrothermal vents are a significant source of oceanic iron. Although hydrothermal iron rapidly precipitates as inorganic minerals on mixing with seawater, it can be stabilized by organic matter and dispersed more widely than previously recognized. The nature and source of this organic matter is unknown. Here we show that microbial genes involved in cellular iron uptake are highly expressed in the Guaymas Basin deep-sea hydrothermal plume. The nature of these microbial iron transporters, taken together with the low concentration of dissolved iron and abundance of particulate iron in the plume, indicates that iron minerals are the target for this microbial scavenging and uptake. Our findings indicate that cellular iron uptake is a major process in plume microbial communities and suggest new mechanisms for generating Fe-C complexes. This 'microbial iron pump' could represent an important mode of converting hydrothermal iron into bioavailable forms that can be dispersed throughout the oceans. PMID:24496055

Li, Meng; Toner, Brandy M; Baker, Brett J; Breier, John A; Sheik, Cody S; Dick, Gregory J

2014-01-01

319

Iron regulatory protein 1 sustains mitochondrial iron loading and function in frataxin deficiency.  

PubMed

Mitochondrial iron accumulation is a hallmark of diseases associated with impaired iron-sulfur cluster (Fe-S) biogenesis, such as Friedreich ataxia linked to frataxin (FXN) deficiency. The pathophysiological relevance of the mitochondrial iron loading and the underlying mechanisms are unknown. Using a mouse model of hepatic FXN deficiency in combination with mice deficient for iron regulatory protein 1 (IRP1), a key regulator of cellular iron metabolism, we show that IRP1 activation in conditions of Fe-S deficiency increases the available cytosolic labile iron pool. Surprisingly, our data indicate that IRP1 activation sustains mitochondrial iron supply and function rather than driving detrimental iron overload. Mitochondrial iron accumulation is shown to depend on mitochondrial dysfunction and heme-dependent upregulation of the mitochondrial iron importer mitoferrin-2. Our results uncover an unexpected protective role of IRP1 in pathological conditions associated with altered Fe-S metabolism. PMID:25651183

Martelli, Alain; Schmucker, Stéphane; Reutenauer, Laurence; Mathieu, Jacques R R; Peyssonnaux, Carole; Karim, Zoubida; Puy, Hervé; Galy, Bruno; Hentze, Matthias W; Puccio, Hélène

2015-02-01

320

IRON BIOMINERALS AS BIOMARKERS Joseph L. Kirschvink  

E-print Network

IRON BIOMINERALS AS BIOMARKERS Joseph L. Kirschvink Division of Geological and Planetary Sciences California Institute of Technology Abstract Because iron is an essential trace element in virtually all the evolution of a wide variety of iron acquisition and storage mecha- nisms. Many of these involve

Kirschvink, Joseph L.

321

Ligand iron catalysts for selective hydrogenation  

DOEpatents

Disclosed are iron ligand catalysts for selective hydrogenation of aldehydes, ketones and imines. A catalyst such as dicarbonyl iron hydride hydroxycyclopentadiene) complex uses the OH on the five member ring and hydrogen linked to the iron to facilitate hydrogenation reactions, particularly in the presence of hydrogen gas.

Casey, Charles P. (Madison, WI); Guan, Hairong (Cincinnati, OH)

2010-11-16

322

4, 249275, 2007 Effects of iron on  

E-print Network

BGD 4, 249­275, 2007 Effects of iron on diatom stoichiometry L. J. Hoffmann et al. Title Page of iron on the elemental stoichiometry during EIFEX and in the diatoms Fragilariopsis kerguelensis #12;BGD 4, 249­275, 2007 Effects of iron on diatom stoichiometry L. J. Hoffmann et al. Title Page

Paris-Sud XI, Université de

323

Iron Deficiency in Autism and Asperger Syndrome.  

ERIC Educational Resources Information Center

Retrospective analysis of the full blood count and, when available, serum ferritin measurements of 96 children (52 with autism and 44 with Asperger syndrome) found six autistic children had iron deficiency and 12 of the 23 autistic children with serum ferritin measures were iron deficient. Far fewer Asperger children were iron deficient. Results…

Latif, A.; Heinz, P.; Cook, R.

2002-01-01

324

The Ins and Outs of Iron Homeostasis  

NSDL National Science Digital Library

Iron is an essential element that is toxic when it accumulates in excess. Intricate regulatory mechanisms have evolved to maintain iron homeostasis within cells and between different tissues of complex organisms. This review discusses the proteins involved in iron transport and storage and their regulation in health and disease.

Adriana Donovan (Harvard Medical School, ChildrenÃÂs Hospital Boston, Dana-Farber Cancer Institute); Cindy N. Roy (Harvard Medical School ChildrenÃÂs Hospital Boston, Dana-Farber Cancer Institute); Nancy C. Andrews (Harvard Medical School ChildrenÃÂs Hospital Boston, Dana-Farber Cancer Institute,)

2006-04-01

325

In vivo iron metabolism by IRMS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Iron isotopes are used in both biological and geological investigations. Three low-abundance stable isotopes are available for human studies. They have been widely used to study iron metabolism. They have provided valuable insights into iron deficiency, one of the most common micronutrient deficienc...

326

Hepcidin in human iron disorders: diagnostic implications  

Microsoft Academic Search

BACKGROUND: The peptide hormone hepcidin plays a central role in regulating dietary iron absorption and body iron distribution. Many human diseases are associated with alterations in hepcidin concentrations. The measurement of hepcidin in biological fluids is therefore a promising tool in the diagnosis and management of medical conditions in which iron metabolism is affected. CONTENT: We describe hepcidin structure, kinetics,

J. J. C. Kroot; H. Tjalsma; R. E. Fleming; D. W. Swinkels

2011-01-01

327

Marine Siderophores and Microbial Iron Mobilization  

Microsoft Academic Search

Iron is essential for the growth of nearly all microorganisms yet iron is only sparingly soluble near the neutral pH, aerobic conditions in which many microorganisms grow. The pH of ocean water is even higher, thereby further lowering the concentration of dissolved ferric ion. To compound the problem of availability, the total iron concentration is surprisingly low in surface ocean

Alison Butler

2005-01-01

328

Electrolytic Corrosion of Iron and Copper  

Microsoft Academic Search

IT is generally accepted that if cast iron and copper are coupled together in a brine solution, the iron, being the less noble member, is likely to suffer corrosion. The copper, on the other hand, will be made `more negative' by contact with the iron and will be prevented in greater or less degree from corroding. The classical work on

W. F. Higgins

1954-01-01

329

Micromilling enhances iron bioaccessibility from wholegrain wheat.  

PubMed

Cereals constitute important sources of iron in human diet; however, much of the iron in wheat is lost during processing for the production of white flour. This study employed novel food processing techniques to increase the bioaccessibility of naturally occurring iron in wheat. Iron was localized in wheat by Perl's Prussian blue staining. Soluble iron from digested wheat flour was measured by a ferrozine spectrophotometric assay. Iron bioaccessibility was determined using an in vitro simulated peptic-pancreatic digestion, followed by measurement of ferritin (a surrogate marker for iron absorption) in Caco-2 cells. Light microscopy revealed that iron in wheat was encapsulated in cells of the aleurone layer and remained intact after in vivo digestion and passage through the gastrointestinal tract. The solubility of iron in wholegrain wheat and in purified wheat aleurone increased significantly after enzymatic digestion with Driselase, and following mechanical disruption using micromilling. Furthermore, following in vitro simulated peptic-pancreatic digestion, iron bioaccessibility, measured as ferritin formation in Caco-2 cells, from micromilled aleurone flour was significantly higher (52%) than from whole aleurone flour. Taken together our data show that disruption of aleurone cell walls could increase iron bioaccessibility. Micromilled aleurone could provide an alternative strategy for iron fortification of cereal products. PMID:25380143

Latunde-Dada, G O; Li, X; Parodi, A; Edwards, C H; Ellis, P R; Sharp, P A

2014-11-19

330

Iron Homeostasis, Oxidative Stress, and DNA Damage  

Microsoft Academic Search

Cellular DNA damage under prooxidant conditions has been shown to be mediated by iron. In fact, iron is an important element in the establishment of a prooxidant status in the cell. It is discussed that there exists a mutual dependence between iron metabolism and oxidative stress. Changes in the former by means of genetic manipulation bring about modification in the

Rogerio Meneghini

1997-01-01

331

Voice Modulations in German Ironic Speech  

ERIC Educational Resources Information Center

Previous research has shown that in different languages ironic speech is acoustically modulated compared to literal speech, and these modulations are assumed to aid the listener in the comprehension process by acting as cues that mark utterances as ironic. The present study was conducted to identify paraverbal features of German "ironic criticism"…

Scharrer, Lisa; Christmann, Ursula; Knoll, Monja

2011-01-01

332

Introduction Southern Ocean natural iron fertilization  

E-print Network

Introduction Southern Ocean natural iron fertilization The surface waters of the Southern Ocean Experiment (SOIREE, e.g. Abraham et al., 2000; Boyd et al., 2000) and Southern Ocean Iron Fertilization casting doubt on the potential for geoengi- neering climate via iron fertilization (e.g. Zeebe and Archer

333

Correcting Iron Deficiencies in Grain Sorghum  

E-print Network

tial for chlorosis when grown on high- ese hybrids lack the ability to fully specif_ied and the iron should be determined by atomic absorption or a method that best indicates available iron in production f_ields. The ICAP (Inductive Coupled Argon Plasma... absorption or a method that bes available iron in prod The ICAP (Inductiv method of analysis is pr ...

Livingston, Stephen; Coffman, Cloyce G.; Unruh, L. G.

1996-02-20

334

Iron, brain ageing and neurodegenerative disorders  

Microsoft Academic Search

There is increasing evidence that iron is involved in the mechanisms that underlie many neurodegenerative diseases. Conditions such as neuroferritinopathy and Friedreich ataxia are associated with mutations in genes that encode proteins that are involved in iron metabolism, and as the brain ages, iron accumulates in regions that are affected by Alzheimer's disease and Parkinson's disease. High concentrations of reactive

Moussa B. H. Youdim; Peter Riederer; James R. Connor; Robert R. Crichton; Luigi Zecca

2004-01-01

335

Iron-limited growth and kinetics of iron uptake in Magnetospirillum gryphiswaldense  

Microsoft Academic Search

Growth and magnetite formation in Magnetospirillum gryphiswaldense MSR-1 were found close to the maximum at an extracellular iron concentration of 15–20 ?M. Ferrous iron was incorporated by\\u000a a slow, diffusion-like process. Several iron chelators including various microbial siderophores were unable to promote transport\\u000a of iron into the cells. In contrast, spent culture fluids stimulated the uptake of ferric iron in

Dirk Schüler; Edmund Baeuerlein

1996-01-01

336

Iron availability and the release of iron-complexing ligands by Emiliania huxleyi  

Microsoft Academic Search

The ubiquitous algal species, Emiliania huxleyi, was incubated in sea water supplemented only with nitrate and phosphate (N and P) without chelating agents to control metal speciation. Growth was slow in a “low-iron” culture containing 1.3 nM iron and was found to be iron-limited, growth-accelerating when a 1-nM iron addition was made. The growth rate in a “high-iron” culture (5.4

Marie Boye

2000-01-01

337

Dynamic transition in supercritical iron  

NASA Astrophysics Data System (ADS)

Recent advance in understanding the supercritical state posits the existence of a new line above the critical point separating two physically distinct states of matter: rigid liquid and non-rigid gas-like fluid. The location of this line, the Frenkel line, remains unknown for important real systems. Here, we map the Frenkel line on the phase diagram of supercritical iron using molecular dynamics simulations. On the basis of our data, we propose a general recipe to locate the Frenkel line for any system, the recipe that importantly does not involve system-specific detailed calculations and relies on the knowledge of the melting line only. We further discuss the relationship between the Frenkel line and the metal-insulator transition in supercritical liquid metals. Our results enable predicting the state of supercritical iron in several conditions of interest. In particular, we predict that liquid iron in the Jupiter core is in the ``rigid liquid'' state and is highly conducting. We finally analyse the evolution of iron conductivity in the core of smaller planets such as Earth and Venus as well as exoplanets: as planets cool off, the supercritical core undergoes the transition to the rigid-liquid conducting state at the Frenkel line.

Fomin, Yu. D.; Ryzhov, V. N.; Tsiok, E. N.; Brazhkin, V. V.; Trachenko, K.

2014-11-01

338

Dynamic transition in supercritical iron  

PubMed Central

Recent advance in understanding the supercritical state posits the existence of a new line above the critical point separating two physically distinct states of matter: rigid liquid and non-rigid gas-like fluid. The location of this line, the Frenkel line, remains unknown for important real systems. Here, we map the Frenkel line on the phase diagram of supercritical iron using molecular dynamics simulations. On the basis of our data, we propose a general recipe to locate the Frenkel line for any system, the recipe that importantly does not involve system-specific detailed calculations and relies on the knowledge of the melting line only. We further discuss the relationship between the Frenkel line and the metal-insulator transition in supercritical liquid metals. Our results enable predicting the state of supercritical iron in several conditions of interest. In particular, we predict that liquid iron in the Jupiter core is in the “rigid liquid” state and is highly conducting. We finally analyse the evolution of iron conductivity in the core of smaller planets such as Earth and Venus as well as exoplanets: as planets cool off, the supercritical core undergoes the transition to the rigid-liquid conducting state at the Frenkel line. PMID:25424664

Fomin, Yu. D.; Ryzhov, V. N.; Tsiok, E. N.; Brazhkin, V. V.; Trachenko, K.

2014-01-01

339

CCMR: Environmentally Benign Iron Catalysts  

NSDL National Science Digital Library

A new para substituted iPrPDI ligand was synthesized using methods previously described1. iPrPDI-CH2TMS, a bright yellow solid was isolated in moderate yields. An iron catalyst, iPrPDI-(CH2TMS)FeBr2 was synthesized and tested in a polymerization reaction with preliminary success.

Brown, Kristi L.

2007-08-29

340

FUGITIVE EMISSIONS FROM IRON FOUNDRIES  

EPA Science Inventory

The report describes the assessment of fugitive emissions of air pollutants discharged from process operations in iron foundries, and the need for the development of control technology for the most critical sources. Data indicates that the most significant fugitive emissions cont...

341

Iron Deficiency and Bariatric Surgery  

PubMed Central

It is estimated that the prevalence of anaemia in patients scheduled for bariatric surgery is higher than in the general population and the prevalence of iron deficiencies (with or without anaemia) may be higher as well. After surgery, iron deficiencies and anaemia may occur in a higher percentage of patients, mainly as a consequence of nutrient deficiencies. In addition, perioperative anaemia has been related with increased postoperative morbidity and mortality and poorer quality of life after bariatric surgery. The treatment of perioperative anaemia and nutrient deficiencies has been shown to improve patients’ outcomes and quality of life. All patients should undergo an appropriate nutritional evaluation, including selective micronutrient measurements (e.g., iron), before any bariatric surgical procedure. In comparison with purely restrictive procedures, more extensive perioperative nutritional evaluations are required for malabsorptive procedures due to their nutritional consequences. The aim of this study was to review the current knowledge of nutritional deficits in obese patients and those that commonly appear after bariatric surgery, specifically iron deficiencies and their consequences. As a result, some recommendations for screening and supplementation are presented. PMID:23676549

Jáuregui-Lobera, Ignacio

2013-01-01

342

ENVIRONMENTAL ASSESSMENT OF IRON CASTING  

EPA Science Inventory

Sampling of ductile iron casting in green sand molds with phenolic isocyanate cores and in phenol-formaldehyde bound shell molds did not provide definitive proof that environmentally hazardous organic emission occur. Both molding systems produced the same type of major emissions,...

343

Carcinogenesis studies with iron oxides.  

PubMed

Seven different types of iron oxide were examined for carcinogenic properties in intratracheal instillation and intraperitoneal injection tests on rats, which represent particularly sensitive methods for local carcinogenic effects. The total doses lay in the range of maximum tolerance (390/1,530 mg/kg i.t. or 600 mg/kg i.p.). With one exception, at least 50 male and 50 female Sprague-Dawley rats were used per test group, control group and route of administration. Two iron oxides were additionally instilled intratracheally in combination with benzo[a]pyrene. No carcinogenic effect could be demonstrated for the test iron oxides RBW 07105/SV2 (fibrous, magnetic, surface doped with 1.85% cobalt), development product Bayferrox AC 5100 M (fibrous, magnetic, bulk doped with 2.1% cobalt), Bayferrox 1352 (fibrous alpha-Fe2O3), Bayferrox 920 (fibrous alpha-FeOOH), Bayferrox 130 (cubic alpha-Fe2O3), Bayferrox 306 (cubic Fe3O4), or Brazilian iron ore AC 5031 N (alpha-Fe2O3). PMID:1797572

Steinhoff, D; Mohr, U; Hahnemann, S

1991-01-01

344

Iron, anemia and hepcidin in malaria  

PubMed Central

Malaria and iron have a complex but important relationship. Plasmodium proliferation requires iron, both during the clinically silent liver stage of growth and in the disease-associated phase of erythrocyte infection. Precisely how the protozoan acquires its iron from its mammalian host remains unclear, but iron chelators can inhibit pathogen growth in vitro and in animal models. In humans, iron deficiency appears to protect against severe malaria, while iron supplementation increases risks of infection and disease. Malaria itself causes profound disturbances in physiological iron distribution and utilization, through mechanisms that include hemolysis, release of heme, dyserythropoiesis, anemia, deposition of iron in macrophages, and inhibition of dietary iron absorption. These effects have significant consequences. Malarial anemia is a major global health problem, especially in children, that remains incompletely understood and is not straightforward to treat. Furthermore, the changes in iron metabolism during a malaria infection may modulate susceptibility to co-infections. The release of heme and accumulation of iron in granulocytes may explain increased vulnerability to non-typhoidal Salmonella during malaria. The redistribution of iron away from hepatocytes and into macrophages may confer host resistance to superinfection, whereby blood-stage parasitemia prevents the development of a second liver-stage Plasmodium infection in the same organism. Key to understanding the pathophysiology of iron metabolism in malaria is the activity of the iron regulatory hormone hepcidin. Hepcidin is upregulated during blood-stage parasitemia and likely mediates much of the iron redistribution that accompanies disease. Understanding the regulation and role of hepcidin may offer new opportunities to combat malaria and formulate better approaches to treat anemia in the developing world. PMID:24910614

Spottiswoode, Natasha; Duffy, Patrick E.; Drakesmith, Hal

2014-01-01

345

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

PubMed Central

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

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

2013-01-01

346

Effect of Tin-mesoporphyrin, an inhibitor of haem catabolism, on intestinal iron absorption.  

PubMed

Haem biosynthesis is the most important destination for absorbed iron, hence it can be hypothesized that iron absorption regulation should be integrated with haem metabolism. As an initial step to test this hypothesis, the effect on iron absorption of Tin-mesoporphyrin (SnMP), inhibitor of haem oxygenase, altering haem and its biosynthetic intermediates, was studied. Mice injected with SnMP (5-25 micro mol/kg daily for up to 3 d) showed dose-dependent increases in intestinal iron absorption measured in vivo and in vitro. In order to investigate the effects of SnMP, enzymes and intermediates of haem metabolism were measured. Hepatic 5-amino-laevulinate (ALA) synthase activity (pmol/min/mg protein) was significantly reduced in SnMP-treated mice (10 and 25 micro mol/kg daily for 3 d) (mean +/- standard deviation, control 11.2 +/- 2.6; treated 6.3 +/- 1.7; P < 0.01). Hepatic ALA dehydratase activity (pmol porphobilinogen/mg protein/min) showed significant reductions following SnMP treatment (control 180 +/- 60, treated 130 +/- 50; P < 0.05). The effect of SnMP on iron absorption was reversible, with absorption returning to normal after 3 d. Furthermore, the effect of SnMP on duodenal iron absorption was abolished by the simultaneous injection of ALA (6 micro mol/l). ALA alone had no effect on iron absorption. In-vitro studies using duodenal fragments isolated from mice treated with SnMP (10 micro mol/kg daily for 3 d), showed significant increases (P < 0.05) in both mucosal iron uptake and Fe(III) reducing activity. We conclude that intermediates in haem metabolism, in particular levels of ALA, may play a role in duodenal iron absorption. PMID:12846900

Laftah, Abas H; Raja, Kishor; Simpson, Robert J; Peters, Timothy J

2003-07-01

347

Adipocyte iron regulates adiponectin and insulin sensitivity  

PubMed Central

Iron overload is associated with increased diabetes risk. We therefore investigated the effect of iron on adiponectin, an insulin-sensitizing adipokine that is decreased in diabetic patients. In humans, normal-range serum ferritin levels were inversely associated with adiponectin, independent of inflammation. Ferritin was increased and adiponectin was decreased in type 2 diabetic and in obese diabetic subjects compared with those in equally obese individuals without metabolic syndrome. Mice fed a high-iron diet and cultured adipocytes treated with iron exhibited decreased adiponectin mRNA and protein. We found that iron negatively regulated adiponectin transcription via FOXO1-mediated repression. Further, loss of the adipocyte iron export channel, ferroportin, in mice resulted in adipocyte iron loading, decreased adiponectin, and insulin resistance. Conversely, organismal iron overload and increased adipocyte ferroportin expression because of hemochromatosis are associated with decreased adipocyte iron, increased adiponectin, improved glucose tolerance, and increased insulin sensitivity. Phlebotomy of humans with impaired glucose tolerance and ferritin values in the highest quartile of normal increased adiponectin and improved glucose tolerance. These findings demonstrate a causal role for iron as a risk factor for metabolic syndrome and a role for adipocytes in modulating metabolism through adiponectin in response to iron stores. PMID:22996660

Gabrielsen, J. Scott; Gao, Yan; Simcox, Judith A.; Huang, Jingyu; Thorup, David; Jones, Deborah; Cooksey, Robert C.; Gabrielsen, David; Adams, Ted D.; Hunt, Steven C.; Hopkins, Paul N.; Cefalu, William T.; McClain, Donald A.

2012-01-01

348

Effect of atmospheric organics on iron bioavailability  

NASA Astrophysics Data System (ADS)

Iron delivered to the ocean's surface through atmospheric pathways is of specific interest for the marine environment and plays a vital role in the earth's biogeochemical cycle. The deposition of atmospheric iron to the ocean's surface may be an important control on primary productivity in vast areas of the global oceans. Near source regions iron is primarily bound in the form of insoluble iron-oxyhydroxides and aluminosilicate minerals. Once airborne, however, iron can be mobilized from the minerals through the effect of acidic trace gases, organic acids, and sunlight initiating a complex cycling between ferric (Fe(III)) and ferrous (Fe(II)) forms of iron. Due to the higher solubility of many Fe(II) salts compared to Fe(III) salts, light-induced photochemical cycling of iron in the presence of different levels of hydrogen peroxide and organic compounds could strongly influence iron mobilization in atmospheric aerosols and cloud droplets. In this study the role of atmospheric organics on biogeochemical cycling of iron is examined. Experiments were conducted to quantify effects of atmospheric organics on 1) Fe(II)/Fe(III) cycling in aqueous aerosols and cloud droplets and 2) bioavailability of iron after deposition to the ocean's surface. Fe(II) was detected by absorbance spectrophotometry using the Ferrozine technique and total soluble iron was determined by addition of hydroxylamine to reduce Fe(III) to Fe(II). Our results indicate that atmospheric organics, when mixed with mineral dust, could play an important role for marine biogeochemistry and carbon cycling.

Hurley, D.; Meskhidze, N.; Petters, M. D.

2013-05-01

349

Vacancy coalescence during oxidation of iron nanoparticles  

SciTech Connect

In the present work, we analyze the geometry and composition of the nanostructures obtained from the oxidation of iron nanoparticles. The initial oxidation of iron takes place by outward diffusion of cations through the growing oxide shell. This net material flow is balanced by an opposite flow of vacancies, which coalesce at the metal/oxide interface. Thus, the partial oxidation of colloidal iron nanoparticles leads to the formation of core-void-shell nanostructures. Furthermore, the complete oxidation of iron nanoparticles in the 3-8 nm size range leads to the formation of hollow iron oxide nanoparticles. We analyze the size and temperature range in which vacancy coalescence during oxidation of amine-stabilized iron nanoparticles takes place. Maghemite is the crystallographic structure obtained from the complete oxidation of iron nanoparticles under our synthetic conditions.

Cabot, Andreu; Puntes, Victor F.; Shevchenko, Elena; Yin, Yadong; Balcells, Lluis; Markus, Matthew A.; Hughes, Steven M.; Alivisatos, A. Paul

2007-06-14

350

Experimental Investigation of High-Temperature Iron Isotope Fractionation in the Iron-Iron Sulfide System  

NASA Astrophysics Data System (ADS)

Several recent studies have suggested that isotopes of Fe and other mid-weight elements can be fractionated at high temperatures. Reduction-oxidation reactions have been proposed as a mechanism by which these fractionations are produced. Specifically in studies of iron meteorites that contain iron sulfide, the sulfidation reaction associated with the formation of troilite has been invoked in order to explain the Fe isotope fractionations reported in these samples (Williams et al., Eos, Transactions, American Geophysical Union, vol.85, no.47, 2004). We carried out a series of experiments in order to examine the plausibility of the sulfidation reaction as a mechanism for generating high-temperature Fe isotope fractionation. Experiments were carried out using a solid-medium piston-cylinder device in which a homogenized powder comprised of high-purity Fe metal and sulfur was packed into a fused-quartz capsule and equilibrated at high temperature and pressure conditions (1000°C, 10 kb) for varying lengths of time (6 to 168 hours). The experiments produced two equilibrium phases: solid Fe metal and solid Fe sulfide (troilite). Electron microprobe analyses of the charges indicate that both phases are pure and homogeneous with Fe metal representing the iron phase and stoichiometric troilite representing the iron sulfide phase. Analysis of the Fe isotopic composition of the experimentally produced phases was carried out using laser ablation-multi collector-inductively coupled plasma-mass spectrometer (LA-MC-ICP-MS) on the Thermo Finnigan Neptune. Results indicate that no systematic fractionation occurred in the experiments, within the analytical resolution of the measurements (external reproducibility approximately 500 ppm). While the iron sulfide displayed a systematically light isotopic composition (-0.30 ?57/54Fe to -0.07 ?57/54Fe) relative to IRMM-014, it was not always lighter then the corresponding metal phase (-0.47 ?57/54Fe to 0.32 ?57/54Fe).

Homburg, J. M.; Gaetani, G. A.; Sims, K. W.

2005-12-01

351

Iron Deficiency in Pregnancy and the Rationality of Iron Supplements Prescribed During Pregnancy  

PubMed Central

Iron deficiency with its resultant anemia is probably the most widespread micronutrient deficiency in the world. Women who are pregnant or lactating and young children are the most affected, especially in the developing world. Despite that only 1 to 3 mg of absorbed iron is required daily at different stages of life, most diets remain deficient. Failure to include iron-rich foods in the diet and inappropriate dietary intake coupled with wide variation in bioavailability (based on the presence of iron absorption inhibitors in the diet) are some of the important factors responsible for iron deficiency. Iron supplementation can be targeted to high-risk groups (eg, pregnant women) and can be cost-effective. Iron fortification of food can prevent iron deficiency in at-risk populations. Selective plant breeding and genetic engineering are promising new approaches to improve dietary iron nutrition quality. PMID:19242589

Gautam, Chander Shekhar; Saha, Lekha; Sekhri, Kavita; Saha, Pradip Kumar

2008-01-01

352

Iron regulatory proteins control a mucosal block to intestinal iron absorption.  

PubMed

Mammalian iron metabolism is regulated systemically by the hormone hepcidin and cellularly by iron regulatory proteins (IRPs) that orchestrate a posttranscriptional regulatory network. Through ligand-inducible genetic ablation of both IRPs in the gut epithelium of adult mice, we demonstrate that IRP deficiency impairs iron absorption and promotes mucosal iron retention via a ferritin-mediated "mucosal block." We show that IRP deficiency does not interfere with intestinal sensing of body iron loading and erythropoietic iron need, but rather alters the basal expression of the iron-absorption machinery. IRPs thus secure sufficient iron transport across absorptive enterocytes by restricting the ferritin "mucosal block" and define a basal set point for iron absorption upon which IRP-independent systemic regulatory inputs are overlaid. PMID:23523353

Galy, Bruno; Ferring-Appel, Dunja; Becker, Christiane; Gretz, Norbert; Gröne, Hermann-Josef; Schümann, Klaus; Hentze, Matthias W

2013-03-28

353

POLLUTION EFFECTS OF ABNORMAL OPERATIONS IN IRON AND STEEL MAKING. VOLUME 1. TECHNICAL REPORT  

EPA Science Inventory

The report is the first in a six-volume series considering abnormal operating conditions (AOCs) in the primary section (sintering, blast furnace ironmaking, open hearth, electric furnace, and basic oxygen steelmaking) of an integrated iron and steel plant. Pollution standards, ge...

354

Characterization of iron binding in IscA, an ancient iron-sulphur cluster assembly protein.  

PubMed Central

Iron-sulphur clusters are one of the most common types of redox centre in biology. At least six proteins (IscS, IscU, IscA, HscB, HscA and ferredoxin) have been identified as being essential for the biogenesis of iron-sulphur proteins in bacteria. It has been shown that IscS is a cysteine desulphurase that provides sulphur for iron-sulphur clusters, and that IscU is a scaffold for the IscS-mediated assembly of iron-sulphur clusters. The iron donor for iron-sulphur clusters, however, remains elusive. Here we show that IscA is an iron binding protein with an apparent iron association constant of 3.0x10(19) M(-1), and that iron-loaded IscA can provide iron for the assembly of transient iron-sulphur clusters in IscU in the presence of IscS and L-cysteine in vitro. The results suggest that IscA is capable of recruiting intracellular iron and delivering iron for iron-sulphur clusters in proteins. PMID:14720122

Ding, Huangen; Clark, Robert J

2004-01-01

355

Iron stable isotopes track pelagic iron cycling during a subtropical phytoplankton bloom.  

PubMed

The supply and bioavailability of dissolved iron sets the magnitude of surface productivity for ?40% of the global ocean. The redox state, organic complexation, and phase (dissolved versus particulate) of iron are key determinants of iron bioavailability in the marine realm, although the mechanisms facilitating exchange between iron species (inorganic and organic) and phases are poorly constrained. Here we use the isotope fingerprint of dissolved and particulate iron to reveal distinct isotopic signatures for biological uptake of iron during a GEOTRACES process study focused on a temperate spring phytoplankton bloom in subtropical waters. At the onset of the bloom, dissolved iron within the mixed layer was isotopically light relative to particulate iron. The isotopically light dissolved iron pool likely results from the reduction of particulate iron via photochemical and (to a lesser extent) biologically mediated reduction processes. As the bloom develops, dissolved iron within the surface mixed layer becomes isotopically heavy, reflecting the dominance of biological processing of iron as it is removed from solution, while scavenging appears to play a minor role. As stable isotopes have shown for major elements like nitrogen, iron isotopes offer a new window into our understanding of the biogeochemical cycling of iron, thereby allowing us to disentangle a suite of concurrent biotic and abiotic transformations of this key biolimiting element. PMID:25535372

Ellwood, Michael J; Hutchins, David A; Lohan, Maeve C; Milne, Angela; Nasemann, Philipp; Nodder, Scott D; Sander, Sylvia G; Strzepek, Robert; Wilhelm, Steven W; Boyd, Philip W

2015-01-01

356

High Fat Diet Subverts Hepatocellular Iron Uptake Determining Dysmetabolic Iron Overload  

PubMed Central

Increased serum ferritin associated with mild hepatic iron accumulation, despite preserved upregulation of the iron hormone hepcidin, is frequently observed in patients with dysmetabolic overload syndrome (DIOS). Genetic factors and Western diet represent predisposing conditions, but the mechanisms favoring iron accumulation in DIOS are still unclear. Aims of this study were to assess the effect a high-fat diet (HFD) on hepatic iron metabolism in an experimental model in rats, to further characterize the effect of free fatty acids on iron metabolism in HepG2 hepatocytes in vitro, and to assess the translational relevance in patients with fatty liver with and without iron accumulation. Despite decreased uptake of dietary iron, rats fed HFD accumulated more hepatic iron than those fed regular diet, which was associated with steatosis development. Hepatic iron accumulation was paralleled by induction of ferritin, in the presence of preserved upregulation of hepcidin, recapitulating the features of DIOS. HFD was associated with increased expression of the major iron uptake protein Transferrin receptor-1 (TfR-1), consistently with upregulation of the intracellular iron sensor Iron regulated protein-1 (IRP1). Supplementation with fatty acids induced TfR-1 and IRP1 in HepG2 hepatocytes, favoring intracellular iron accumulation following exposure to iron salts. IRP1 silencing completely abrogated TfR-1 induction and the facilitation of intracellular iron accumulation induced by fatty acids. Hepatic TfR-1 mRNA levels were upregulated in patients with fatty liver and DIOS, whereas they were not associated with liver fat nor with inflammation. In conclusion, increased exposure to fatty acids subverts hepatic iron metabolism, favoring the induction of an iron uptake program despite hepatocellular iron accumulation. PMID:25647178

Dongiovanni, Paola; Lanti, Claudia; Gatti, Stefano; Rametta, Raffaela; Recalcati, Stefania; Maggioni, Marco; Fracanzani, Anna Ludovica; Riso, Patrizia; Cairo, Gaetano; Fargion, Silvia; Valenti, Luca

2015-01-01

357

Iron status of women is associated with the iron concentration of potable groundwater in rural Bangladesh.  

PubMed

Women of reproductive age are at a high risk of iron deficiency, often as a result of diets low in bioavailable iron. In some settings, the iron content of domestic groundwater sources is high, yet its contribution to iron intake and status has not been examined. In a rural Bangladeshi population of women deficient in dietary iron, we evaluated the association between groundwater iron intake and iron status. In 2008, participants (n = 209 with complete data) were visited to collect data on 7-d food frequency, 7-d morbidity history, 24-h drinking water intake, and rice preparation, and to measure the groundwater iron concentration. Blood was collected to assess iron and infection status. Plasma ferritin (?g/L) and body iron (mg/kg) concentrations were [median (IQR)] 67 (46, 99) and 10.4 ± 2.6, respectively, and the prevalence of iron deficiency (ferritin < 12 ?g/L) was 0%. Daily iron intake from water [42 mg (18, 71)] was positively correlated with plasma ferritin (r = 0.36) and total body iron (r = 0.35) (P < 0.001 for both). In adjusted linear regression analyses, plasma ferritin increased by 6.1% (95% CI: 3.8, 8.4%) and body iron by 0.3 mg/kg (0.2, 0.4) for every 10-mg increase in iron intake from water (P < 0.001). In this rural area of northern Bangladesh, women of reproductive age had no iron deficiency likely attributable to iron consumed from drinking groundwater, which contributed substantially to dietary intake. These findings suggest that iron intake from water should be included in dietary assessments in such settings. PMID:21451130

Merrill, Rebecca D; Shamim, Abu Ahmed; Ali, Hasmot; Jahan, Nusrat; Labrique, Alain B; Schulze, Kerry; Christian, Parul; West, Keith P

2011-05-01

358

Photosynthetic maximum quantum yield increases are an essential component of the Southern Ocean phytoplankton response to iron.  

PubMed

It is well established that an increase in iron supply causes an increase in total oceanic primary production in many regions, but the physiological mechanism driving the observed increases has not been clearly identified. The Southern Ocean iron enrichment experiment, an iron fertilization experiment in the waters closest to Antarctica, resulted in a 9-fold increase in chlorophyll (Chl) concentration and a 5-fold increase in integrated primary production. Upon iron addition, the maximum quantum yield of photosynthesis (phi(m)) rapidly doubled, from 0.011 to 0.025 mol C.mol quanta(-1). Paradoxically, this increase in light-limited productivity was not accompanied by a significant increase in light-saturated productivity (P(max)(b)). P(max)(b), maximum Chl normalized productivity, was 1.34 mg C.mg Chl(-1).h(-1) outside and 1.49 mg C.mg Chl(-1).h(-1) inside the iron-enriched patch. The importance of phi(m) as compared with P(max)(b) in controlling the biological response to iron addition has vast implications for understanding the ecological response to iron. We show that an iron-driven increase in phi(m) is the proximate physiological mechanism affected by iron addition and can account for most of the increases in primary production. The relative importance of phi(m) over P(max)(b) in this iron-fertilized bloom highlights the limitations of often-used primary productivity algorithms that are driven by estimates of P(max)(b) but largely ignore variability in phi(m) and light-limited productivity. To use primary productivity models that include variability in iron supply in prediction or forecasting, the variability of light-limited productivity must be resolved. PMID:18349145

Hiscock, Michael R; Lance, Veronica P; Apprill, Amy M; Bidigare, Robert R; Johnson, Zackary I; Mitchell, B Greg; Smith, Walker O; Barber, Richard T

2008-03-25

359

Iron storage disease in tapirs.  

PubMed

Recent studies of serum iron and iron binding capacity have indicated that tapirs could be at risk of developing hemochromatosis. However, in recent surveys of pathologic findings in tapirs, hemochromatosis was not reported as a cause of death. This study reviews necropsy reports from three species of tapir (Baird's tapir [Tapirus bairdii], Malayan tapir [Tapirus indicus], and Brazilian tapir [Tapirus terrestris]) at the Philadelphia Zoological Garden between 1902 and 1994. Twelve cases of hemosiderosis, including fatal hemochromatosis in two Baird's tapirs, were found among 19 cases examined histologically. Hemochromatosis has previously been reported in the horse, rhinoceros, and in one Brazilian tapir. Dietary factors were investigated but could not be confirmed to have contributed to the incidence of hemosiderosis and hemochromatosis in the three species of tapir in the Philadelphia Zoological Garden collection. PMID:17312812

Bonar, Christopher J; Trupkiewicz, John G; Toddes, Barbara; Lewandowski, Albert H

2006-03-01

360

Iron oxidation by Thiobacillus ferrooxidans  

SciTech Connect

Several investigators have shown that microorganisms are involved in many naturally occurring oxidation processes. At present, microbial leaching, which is the solubilization of metals catalyzed by microorganisms, is widely used commercially to produce copper, and to a lesser extent uranium, from low-grade mining wastes. Microbial leaching can also be used as a pretreatment step in the mining of precious metals, such as gold and silver. In this application, the solubilization of pyrite makes the precious metals more accessible for cyanide leaching. Because ferrous iron oxidation is such an important reaction in microbial leaching operations, this study was undertaken to examine factors affecting the rate of ferrous iron oxidation in the presence of T. ferrooxidans.

Kang, Sunki; Sproull, R.D. [Oregon State Univ., Corvallis, OR (United States)

1991-12-31

361

Iron quantification of microbleeds in postmortem brain.  

PubMed

Brain microbleeds (BMB) are associated with chronic and acute cerebrovascular disease and present a source of pathologic iron to the brain proportional to extravasated blood. Therefore, BMB iron content is potentially a valuable biomarker. We tested noninvasive phase image methods to quantify iron content and estimate true source diameter (i.e., unobscured by the blooming effect) of BMB in postmortem human tissue. Tissue slices containing BMB were imaged using a susceptibility weighted imaging protocol at 11.7T. BMB lesions were assayed for iron content using atomic absorption spectrometry. Measurements of geometric features in phase images were related to lesion iron content and source diameter using a mathematical model. BMB diameter was estimated by image feature geometry alone without explicit relation to the magnetic susceptibility. A strong linear relationship (R(2) = 0.984, P < 0.001) predicted by theory was observed in the experimental data, presenting a tentative standardization curve where BMB iron content in similar tissues could be calculated. In addition, we report BMB iron mass measurements, as well as upper bound diameter and lower bound iron concentration estimates. Our methods potentially allows the calculation of brain iron load indices based on BMB iron content and classification of BMB by size unobscured by the blooming effect. PMID:21590801

McAuley, Grant; Schrag, Matthew; Barnes, Samuel; Obenaus, Andre; Dickson, April; Holshouser, Barbara; Kirsch, Wolff

2011-06-01

362

Current approach to iron chelation in children.  

PubMed

Transfusion-dependent children, mostly with thalassaemia major, but also and occasionally to a more significant degree, with inherited bone marrow failures, can develop severe iron overload in early life. Moreover, chronic conditions associated with ineffective erythropoiesis, such as non-transfusion-dependent thalassaemia (NTDT), may lead to iron overload through increased gut absorption of iron starting in childhood. Currently, the goal of iron chelation has shifted from treating iron overload to preventing iron accumulation and iron-induced end-organ complications, in order to achieve a normal pattern of complication-free survival and of quality of life. New chelation options increase the likelihood of achieving these goals. Timely initiation, close monitoring and continuous adjustment are the cornerstones of optimal chelation therapy in children, who have a higher transfusional requirements compared to adults in order to reach haemoglobin levels adequate for normal growth and development. Despite increased knowledge, there are still uncertainties about the level of body iron at which iron chelation therapy should be started and about the appropriate degree of iron stores' depletion. PMID:24646011

Aydinok, Yesim; Kattamis, Antonis; Viprakasit, Vip

2014-06-01

363

Reactive iron in marine sediments  

Microsoft Academic Search

A combined field\\/laboratory study has been undertaken to explore the mineralogy, concentrations and reactivity (towards sulfide) of iron in marine sediments. Also considered is the importance of bacterial Fe liberation in regulating pore-water chemistry. Two contrasting marine environments are included; one is the relatively Fe-poor FOAM site and the other is the Fe-rich sediment of the subaqueous Mississippi Delta. Results

Donald E. Canfield

1989-01-01

364

F-8 Iron Bird Cockpit  

NASA Technical Reports Server (NTRS)

The F-8 DFBW (Digital-Fly-By-Wire) simulator used an 'Iron-Bird' for its cockpit. It was used from 1971 to 1986. The F-8 DFBW simulator was used in the development, testing, and validation of an all digital flight-control system installed in the F-8 aircraft that replaced the normal mechanical/hydraulic controls. Many military and commercial aircraft have digital flight control systems based on the technologies developed at NASA Dryden.

1975-01-01

365

Intravenous iron in inflammatory bowel disease.  

PubMed

The prevalence of anemia across studies on patients with inflammatory bowel disease (IBD) is high (30%). Both iron deficiency (ID) and anemia of chronic disease contribute most to the development of anemia in IBD. The prevalence of ID is even higher (45%). Anemia and ID negatively impact the patient's quality of life. Therefore, together with an adequate control of disease activity, iron replacement therapy should start as soon as anemia or ID is detected to attain a normal hemoglobin (Hb) and iron status. Many patients will respond to oral iron, but compliance may be poor, whereas intravenous (i.v.) compounds are safe, provide a faster Hb increase and iron store repletion, and presents a lower rate of treatment discontinuation. Absolute indications for i.v. iron treatment should include severe anemia, intolerance or inappropriate response to oral iron, severe intestinal disease activity, or use of an erythropoietic stimulating agent. Four different products are principally used in clinical practice, which differ in their pharmacokinetic properties and safety profiles: iron gluconate and iron sucrose (lower single doses), and iron dextran and ferric carboxymaltose (higher single doses). After the initial resolution of anemia and the repletion of iron stores, the patient's hematological and iron parameters should be carefully and periodically monitored, and maintenance iron treatment should be provided as required. New i.v. preparations that allow for giving 1000-1500 mg in a single session, thus facilitating patient management, provide an excellent tool to prevent or treat anemia and ID in this patient population, which in turn avoids allogeneic blood transfusion and improves their quality of life. PMID:19787830

Muñoz, Manuel; Gómez-Ramírez, Susana; García-Erce, José Antonio

2009-10-01

366

Intravenous iron in inflammatory bowel disease  

PubMed Central

The prevalence of anemia across studies on patients with inflammatory bowel disease (IBD) is high (30%). Both iron deficiency (ID) and anemia of chronic disease contribute most to the development of anemia in IBD. The prevalence of ID is even higher (45%). Anemia and ID negatively impact the patient’s quality of life. Therefore, together with an adequate control of disease activity, iron replacement therapy should start as soon as anemia or ID is detected to attain a normal hemoglobin (Hb) and iron status. Many patients will respond to oral iron, but compliance may be poor, whereas intravenous (IV) compounds are safe, provide a faster Hb increase and iron store repletion, and presents a lower rate of treatment discontinuation. Absolute indications for IV iron treatment should include severe anemia, intolerance or inappropriate response to oral iron, severe intestinal disease activity, or use of an erythropoietic stimulating agent. Four different products are principally used in clinical practice, which differ in their pharmacokinetic properties and safety profiles: iron gluconate and iron sucrose (lower single doses), and iron dextran and ferric carboxymaltose (higher single doses). After the initial resolution of anemia and the repletion of iron stores, the patient’s hematological and iron parameters should be carefully and periodically monitored, and maintenance iron treatment should be provided as required. New IV preparations that allow for giving 1000-1500 mg in a single session, thus facilitating patient management, provide an excellent tool to prevent or treat anemia and ID in this patient population, which in turn avoids allogeneic blood transfusion and improves their quality of life. PMID:19787830

Muñoz, Manuel; Gómez-Ramírez, Susana; García-Erce, José Antonio

2009-01-01

367

Iron, phytoplankton growth, and the carbon cycle.  

PubMed

Iron is an essential nutrient for all living organisms. Iron is required for the synthesis of chlorophyll and of several photosynthetic electron transport proteins and for the reduction of CO2, SO4(2-), and NO3(-) during the photosynthetic production of organic compounds. Iron concentrations in vast areas of the ocean are very low (<1 nM) due to the low solubility of iron in oxic seawater. Low iron concentrations have been shown to limit primary production rates, biomass accumulation, and ecosystem structure in a variety of open-ocean environments, including the equatorial Pacific, the subarctic Pacific and the Southern Ocean and even in some coastal areas. Oceanic primary production, the transfer of carbon dioxide into organic carbon by photosynthetic plankton (phytoplankton), is one process by which atmospheric CO2 can be transferred to the deep ocean and sequestered for long periods of time. Accordingly, iron limitation of primary producers likely plays a major role in the global carbon cycle. It has been suggested that variations in oceanic primary productivity, spurred by changes in the deposition of iron in atmospheric dust, control atmospheric CO2 concentrations, and hence global climate, over glacial-interglacial timescales. A contemporary application of this "iron hypothesis" promotes the large-scale iron fertilization of ocean regions as a means of enhancing the ability of the ocean to store anthropogenic CO2 and mitigate 21st century climate change. Recent in situ iron enrichment experiments in the HNLC regions, however, cast doubt on the efficacy and advisability of iron fertilization schemes. The experiments have confirmed the role of iron in regulating primary productivity, but resulted in only small carbon export fluxes to the depths necessary for long-term sequestration. Above all, these experiments and other studies of iron biogeochemistry over the last two decades have begun to illustrate the great complexity of the ocean system. Attempts to engineer this system are likely to provoke a similarly complex, unpredictable response. PMID:16370118

Street, Joseph H; Paytan, Adina

2005-01-01

368

Acute Oxidative Stress following Intravenous Iron Injection in Patients on Chronic Hemodialysis: A Comparison of Iron-Sucrose and Iron-Dextran  

Microsoft Academic Search

Background\\/Aims: Intravascular iron release from parenteral iron formulations can catalyze various harmful oxidative reactions. These topics have mainly been investigated in vivo with iron-sucrose (IS). The aim of our study was to compare IS and iron-dextran (ID) regarding iron release and induction of oxidative stress. Methods: Twenty hemodialysis patients were enrolled. Plasma iron and oxidative stress parameters were measured before

Bergur V. Stefánsson; Börje Haraldsson; Ulf Nilsson

2011-01-01

369

Reactive iron in marine sediments  

NASA Astrophysics Data System (ADS)

A combined field/laboratory study has been undertaken to explore the mineralogy, concentrations and reactivity (towards sulfide) of iron in marine sediments. Also considered is the importance of bacterial Fe liberation in regulating pore-water chemistry. Two contrasting marine environments are included; one is the relatively Fe-poor FOAM site and the other is the Fe-rich sediment of the subaqueous Mississippi Delta. Results show that oxide minerals are the most important Fe phases in early diagenetic pyrite formation. However, viewed separately, lepidocrocite and ferrihydrite are more reactive towards sulfide than goethite and hematite. When Fe oxides are present in relatively high concentrations, dissolved sulfide is nearly absent from sediment pore waters (with concomitant high concentrations of dissolved Fe), even in the presence of active sulfide production by sulfate reduction. A combination of experimental results and diagenetic modelling shows that in some sediments pore water Fe finds it origin in the bacterial reduction of iron oxides. This seems the case even though greater amounts of Fe are reduced by reaction of sulfide with iron oxides. It appears that distinct microenvironments may exist in marine sediments, where, in one microenvironment, sulfide reacts with Fe oxides locally precipitating Fe sulfide minerals. In another, Fe reduced and solubilized by microorganisms migrates freely into solution.

Canfield, Donald E.

1989-03-01

370

Escherichia coli RIC is able to donate iron to iron-sulfur clusters.  

PubMed

Escherichia coli RIC (Repair of Iron Centers) is a diiron protein previously reported to be involved in the repair of iron-sulfur proteins damaged by oxidative or nitrosative stresses, and proposed to act as an iron donor. This possible role of RIC was now examined specifically by evaluating its ability to donate iron ions to apo-iron-sulfur proteins, determining the iron binding constants and assessing the lability of its iron ions. We show, by UV-visible, EPR and resonance Raman spectroscopies that RIC may participate in the synthesis of an iron-sulfur cluster in the apo-forms of the spinach ferredoxin and IscU when in the presence of the sulfide donating system IscS and L-cysteine. Iron binding assays allowed determining the as-isolated and fully reduced RIC dissociation constants for the ferric and ferrous iron of 10-27 M and 10-13 M, respectively. Mössbauer studies revealed that the RIC iron ions are labile, namely when the center is in the mixed-valence redox form as compared with the (?-oxo) diferric one. Altogether, these results suggest that RIC is capable of delivering iron for the formation of iron-sulfur clusters. PMID:24740378

Nobre, Lígia S; Garcia-Serres, Ricardo; Todorovic, Smilja; Hildebrandt, Peter; Teixeira, Miguel; Latour, Jean-Marc; Saraiva, Lígia M

2014-01-01

371

Escherichia coli RIC Is Able to Donate Iron to Iron-Sulfur Clusters  

PubMed Central

Escherichia coli RIC (Repair of Iron Centers) is a diiron protein previously reported to be involved in the repair of iron-sulfur proteins damaged by oxidative or nitrosative stresses, and proposed to act as an iron donor. This possible role of RIC was now examined specifically by evaluating its ability to donate iron ions to apo-iron-sulfur proteins, determining the iron binding constants and assessing the lability of its iron ions. We show, by UV-visible, EPR and resonance Raman spectroscopies that RIC may participate in the synthesis of an iron-sulfur cluster in the apo-forms of the spinach ferredoxin and IscU when in the presence of the sulfide donating system IscS and L-cysteine. Iron binding assays allowed determining the as-isolated and fully reduced RIC dissociation constants for the ferric and ferrous iron of 10?27 M and 10?13 M, respectively. Mössbauer studies revealed that the RIC iron ions are labile, namely when the center is in the mixed-valence redox form as compared with the (?-oxo) diferric one. Altogether, these results suggest that RIC is capable of delivering iron for the formation of iron-sulfur clusters. PMID:24740378

Nobre, Lígia S.; Garcia-Serres, Ricardo; Todorovic, Smilja; Hildebrandt, Peter; Teixeira, Miguel; Latour, Jean-Marc; Saraiva, Lígia M.

2014-01-01

372

Ferritin is the key to dietary iron absorption and tissue iron detoxification in Drosophila melanogaster.  

PubMed

Mammalian ferritin is predominantly in the cytosol, with a minor portion found in plasma. In most insects, including Drosophila melanogaster, ferritin belongs to the secretory type. The functional role of secretory ferritin in iron homeostasis remains poorly understood in insects as well as in mammalians. Here we used Drosophila to dissect the involvement of ferritin in insect iron metabolism. Midgut-specific knockdown of ferritin resulted in iron accumulation in the gut but systemic iron deficiency (37% control), accompanied by retarded development and reduced survival (3% survival), and was rescued by dietary iron supplementation (50% survival) or exacerbated by iron depletion (0% survival). These results suggest an essential role of ferritin in removing iron from enterocytes across the basolateral membrane. Expression of wild-type ferritin in the midgut, especially in the iron cell region, could significantly rescue ferritin-null mutants (first-instar larvae rescued up to early adults), indicating iron deficiency as the major cause of early death for ferritin flies. In many nonintestinal tissues, tissue-specific ferritin knockdown also caused local iron accumulation (100% increase) and resulted in severe tissue damage, as evidenced by cell loss. Overall, our study demonstrated Drosophila ferritin is essential to two key aspects of iron homeostasis: dietary iron absorption and tissue iron detoxification. PMID:23064556

Tang, Xiaona; Zhou, Bing

2013-01-01

373

The development of precipitated iron catalysts with improved stability  

SciTech Connect

The goal of this program is to identify the chemical principles governing the deactivation of precipitated iron catalysts during Fischer-Tropsch synthesis and to use these chemical principles in the design of catalysts suitable for slurry reactors. This report covers testing an iron catalyst. During the last quarter, a new precipitated iron catalyst was prepared and tested in the slurry autoclave reactor at various conditions. This catalyst did not noticeably deactivate during 1250 hours of testing. This quarter, the test was extended to include performance evaluations at different conversion levels ranging from 35 to 88% at 265 and 275{degree}C. The conversion levels were varied by changing the feed rate. The catalytic performance at different conversion intervals was then integrated to approximately predict performance in a bubble column reactor. The run was shut down at the end of 1996 hours because of a 24-hour-power outage. When the power was back on, the run was restarted from room temperature. Catalytic performance during the first 300 hours after the restart-up was monitored. Overall product distributions are being tabulated as analytical laboratory data are obtained. 34 figs., 3 tabs.

Not Available

1990-01-01

374

Structural basis for iron piracy by pathogenic Neisseria  

PubMed Central

SUMMARY Neisseria are obligate human pathogens causing bacterial meningitis, septicemia, and gonorrhea. Neisseria require iron for survival and can extract it directly from human transferrin for transport across the outer membrane. The transport system consists of TbpA, an integral outer membrane protein, and TbpB, a co-receptor attached to the cell surface; both proteins are potentially important vaccine and therapeutic targets. Two key questions driving Neisseria research are: 1) how human transferrin is specifically targeted, and 2) how the bacteria liberate iron from transferrin at neutral pH. To address them, we solved crystal structures of the TbpA-transferrin complex and of the corresponding co-receptor TbpB. We characterized the TbpB-transferrin complex by small angle X-ray scattering and the TbpA-TbpB-transferrin complex by electron microscopy. Collectively, our studies provide a rational basis for the specificity of TbpA for human transferrin, show how TbpA promotes iron release from transferrin, and elucidate how TbpB facilitates this process. PMID:22327295

Noinaj, N.; Easley, N.C.; Oke, M.; Mizuno, N.; Gumbart, J.; Boura, E.; Steere, A.N.; Zak, O.; Aisen, P.; Tajkhorshid, E.; Evans, R.W.; Gorringe, A.R.; Mason, A.B.; Steven, A.C.; Buchanan, S.K.

2012-01-01

375

The iron-regulated staphylococcal lipoproteins  

PubMed Central

Lipoproteins fulfill diverse roles in antibiotic resistance, adhesion, protein secretion, signaling and sensing, and many also serve as the substrate binding protein (SBP) partner to ABC transporters for the acquisition of a diverse array of nutrients including peptides, sugars, and scarcely abundant metals. In the staphylococci, the iron-regulated SBPs are significantly upregulated during iron starvation and function to sequester and deliver iron into the bacterial cell, enabling staphylococci to circumvent iron restriction imposed by the host environment. Accordingly, this subset of lipoproteins has been implicated in staphylococcal pathogenesis and virulence. Lipoproteins also activate the host innate immune response, triggered through Toll-like receptor-2 (TLR2) and, notably, the iron-regulated subset of lipoproteins are particularly immunogenic. In this review, we discuss the iron-regulated staphylococcal lipoproteins with regard to their biogenesis, substrate specificity, and impact on the host innate immune response. PMID:22919632

Sheldon, Jessica R.; Heinrichs, David E.

2012-01-01

376

Lactoferrin and iron absorption in newborn infants.  

PubMed

Results from experiments in this laboratory using 59Fe suggest that bovine lactoferrin (Lf) has no effect on iron absorption in rats. A study was therefore carried out in newborn infants to measure the effects of Lf on iron retention. Bovine Lf was labeled with the stable isotope 58Fe and fed to 7-day-old infants in a standard milk formula. Iron retention was estimated by measuring the unabsorbed 58Fe excreted in the feces during the following 3 days using neutron activation analysis. The results were compared with those obtained from a group of infants fed a similar level of iron as ferric chloride, labeled with 58Fe, together with 30 mg ascorbic acid. There was a very wide variation in percent iron retention amongst the infants but no overall difference between the Lf and ferric chloride groups. This confirms the previous findings in rats that Lf does not influence the availability of nonheme iron. PMID:3431946

Fairweather-Tait, S J; Balmer, S E; Scott, P H; Minski, M J

1987-12-01

377

Iron Chelation Therapy in Myelodysplastic Syndromes  

PubMed Central

Myelodysplastic syndromes (MDS) are a heterogeneous disorder of the hematopoietic stem cells, frequently characterized by anemia and transfusion dependency. In low-risk patients, transfusion dependency can be long lasting, leading to iron overload. Iron chelation therapy may be a therapeutic option for these patients, especially since the approval of oral iron chelators, which are easier to use and better accepted by the patients. The usefulness of iron chelation in MDS patients is still under debate, mainly because of the lack of solid prospective clinical trials that should take place in the future. This review aims to summarize what is currently known about the incidence and clinical consequences of iron overload in MDS patients and the state-of the-art of iron chelation therapy in this setting. We also give an overview of clinical guidelines for chelation in MDS published to date and some perspectives for the future. PMID:20672005

Messa, Emanuela; Cilloni, Daniela; Saglio, Giuseppe

2010-01-01

378

Regulation of heme iron absorption by young children  

Technology Transfer Automated Retrieval System (TEKTRAN)

Heme iron is an important source of dietary iron for children. Little is known of its absorption as only radio-isotopically labeled heme iron has been available to date. We have recently developed a method of intrinsically labeling bovine heme iron in vivo with the stable isotope iron-58. Our object...

379

Iron oxide dissolution and solubility in the presence of siderophores  

Microsoft Academic Search

Iron is an essential trace nutrient for most known organisms. The iron availability is limited by the solubility and the slow dissolution kinetics of iron-bearing mineral phases, particularly in pH neutral or alkaline environments such as carbonatic soils and ocean water. Bacteria, fungi, and plants have evolved iron acquisition systems to increase the bioavailability of iron in such environments. A

Stephan M. Kraemer

2004-01-01

380

Disruption of Iron Homeostasis Increases Phosphine Toxicity in Caenorhabditis elegans  

E-print Network

Disruption of Iron Homeostasis Increases Phosphine Toxicity in Caenorhabditis elegans Ubon Cha-dependent actions of phosphine, in vitro: (1) reduction of ferric iron (Fe3+ ) to ferrous iron (Fe2+ ), (2) release of iron from horse ferritin, (3) and the peroxidation of lipid as a result of iron release from ferritin

Hammock, Bruce D.

381

A Method for the Rapid Detection of Acute Iron Toxicity  

Microsoft Academic Search

In acute iron poisoning,it is necessaryfor rational management to know whether the plasma iron exceeds the transferrin-binding capacity. A method for the rapid determination of iron in plasma is describedwhereby this essential information may be obtained in a few minutes. This test will help to differentiate simple iron in- gestion from acute iron toxicity so the clinician may have a

David S. Fischer

382

Effects of Iron Supplementation and Activity on Serum Iron Depletion and Hemoglobin Levels in Female Athletes  

ERIC Educational Resources Information Center

Research revealed that a four-month basketball training program did not significantly alter serum iron, total iron binding capacity, hemoglobin, and percent saturation levels in female basketball athletes. (JD)

Cooter, G. Rankin; Mowbray, Kathy W.

1978-01-01

383

49 CFR 192.369 - Service lines: Connections to cast iron or ductile iron mains.  

Code of Federal Regulations, 2010 CFR

...CONTINUED) PIPELINE SAFETY TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Customer Meters, Service Regulators, and Service Lines § 192.369 Service lines: Connections to cast iron or ductile iron...

2010-10-01

384

49 CFR 192.369 - Service lines: Connections to cast iron or ductile iron mains.  

Code of Federal Regulations, 2013 CFR

...CONTINUED) PIPELINE SAFETY TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Customer Meters, Service Regulators, and Service Lines § 192.369 Service lines: Connections to cast iron or ductile iron...

2013-10-01

385

49 CFR 192.369 - Service lines: Connections to cast iron or ductile iron mains.  

Code of Federal Regulations, 2011 CFR

...CONTINUED) PIPELINE SAFETY TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Customer Meters, Service Regulators, and Service Lines § 192.369 Service lines: Connections to cast iron or ductile iron...

2011-10-01

386

49 CFR 192.373 - Service lines: Cast iron and ductile iron.  

Code of Federal Regulations, 2010 CFR

...CONTINUED) PIPELINE SAFETY TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Customer Meters, Service Regulators, and Service Lines § 192.373 Service lines: Cast iron and ductile iron. (a) Cast or...

2010-10-01

387

49 CFR 192.373 - Service lines: Cast iron and ductile iron.  

Code of Federal Regulations, 2013 CFR

...CONTINUED) PIPELINE SAFETY TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Customer Meters, Service Regulators, and Service Lines § 192.373 Service lines: Cast iron and ductile iron. (a) Cast or...

2013-10-01

388

49 CFR 192.369 - Service lines: Connections to cast iron or ductile iron mains.  

Code of Federal Regulations, 2012 CFR

...CONTINUED) PIPELINE SAFETY TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Customer Meters, Service Regulators, and Service Lines § 192.369 Service lines: Connections to cast iron or ductile iron...

2012-10-01

389

49 CFR 192.373 - Service lines: Cast iron and ductile iron.  

Code of Federal Regulations, 2012 CFR

...CONTINUED) PIPELINE SAFETY TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Customer Meters, Service Regulators, and Service Lines § 192.373 Service lines: Cast iron and ductile iron. (a) Cast or...

2012-10-01

390

49 CFR 192.373 - Service lines: Cast iron and ductile iron.  

Code of Federal Regulations, 2011 CFR

...CONTINUED) PIPELINE SAFETY TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Customer Meters, Service Regulators, and Service Lines § 192.373 Service lines: Cast iron and ductile iron. (a) Cast or...

2011-10-01

391

A novel regeneration of iron citrate solution by biooxidation of iron-oxidizing bacteria.  

PubMed

Liquid phase oxidation process using chelated iron solution is among the most promising techniques for the hydrogen sulfide removal due to its double advantage of waste minimization and resource recovery. Regeneration of chelated iron is a core reaction in this process. Regeneration of chelated iron in acidic solution is very difficult. In this paper, a novel regeneration of iron citrate in acidic solution by biooxidation of iron-oxidizing bacteria was reported firstly. By using such a process, the influence of iron-oxidizing bacteria on the regeneration rate was investigated. The results demonstrated the regeneration rate with the new technology was increased significantly. The process may contribute to the biooxidation of iron-oxidizing bacteria. Application of this novel process increased the regeneration rate under the optimum conditions, suggesting the iron citrate regeneration process may be a feasible and economical method in application. PMID:25242290

Wang, Y J; Li, D P; Liu, C; Zhan, G Q; He, X H

2014-11-01

392

49 CFR 192.489 - Remedial measures: Cast iron and ductile iron pipelines.  

...PIPELINE SAFETY TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Requirements for Corrosion Control § 192.489 Remedial measures: Cast iron and ductile iron pipelines. (a) General graphitization....

2014-10-01

393

Ferrous versus ferric oral iron formulations for the treatment of iron deficiency: a clinical overview.  

PubMed

Iron deficiency anaemia represents a major public health problem, particularly in infants, young children, pregnant women, and females with heavy menses. Oral iron supplementation is a cheap, safe, and effective means of increasing haemoglobin levels and restoring iron stores to prevent and correct iron deficiency. Many preparations are available, varying widely in dosage, formulation (quick or prolonged release), and chemical state (ferrous or ferric form). The debate over the advantages of ferrous versus ferric formulations is ongoing. In this literature review, the tolerability and efficacy of ferrous versus ferric iron formulations are evaluated. We focused on studies comparing ferrous sulphate preparations with ferric iron polymaltose complex preparations, the two predominant forms of iron used. Current data show that slow-release ferrous sulphate preparations remain the established and standard treatment of iron deficiency, irrespective of the indication, given their good bioavailability, efficacy, and acceptable tolerability demonstrated in several large clinical studies. PMID:22654638

Santiago, Palacios

2012-01-01

394

Investigating the role of transferrin in the distribution of iron, manganese, copper, and zinc.  

PubMed

The essential role of transferrin in mammalian iron metabolism is firmly established. Integral to our understanding of transferrin, studies in hypotransferrinemic mice, a model of inherited transferrin deficiency, have demonstrated that transferrin is essential for iron delivery for erythropoiesis and in the regulation of expression of hepcidin, a hormone that inhibits macrophage and enterocyte iron efflux. Here we investigate a potential role for transferrin in the distribution of three other physiologic metals, manganese, copper, and zinc. We first assessed metal content in transferrin-rich fractions of wild-type mouse sera and demonstrate that although both iron and manganese cofractionated predominantly with transferrin, the absolute levels of manganese are several orders of magnitude lower than those of iron. We next measured metal content in multiple tissues in wild-type and hypotransferrinemic mice of various ages. Tissue metal imbalances were severe for iron and minimal to moderate for some metals in some tissues in hypotransferrinemic mice. Metal levels measured in a transferrin-replete yet hepcidin-deficient and iron-loaded mouse strain suggested that the observed imbalances in tissue copper, zinc, and manganese levels were not all specific to hypotransferrinemic mice or caused directly by transferrin deficiency. Overall, our results suggest that transferrin does not have a primary role in the distribution of manganese, copper, or zinc to tissues and that the abnormalities observed in tissue manganese levels are not attributable to a direct role for transferrin in manganese metabolism but rather are attributable to an indirect effect of transferrin deficiency on hepcidin expression and/or iron metabolism. PMID:24567067

Herrera, Carolina; Pettiglio, Michael A; Bartnikas, Thomas B

2014-08-01

395

Iron line afterglows: how to produce them  

E-print Network

We discuss how a powerful iron line emission can be produced if ~1-5 iron rich solar masses are concentrated in the close vicinity of the burst. Recombination, thermal and fluorescent reflection are discussed. We find that recombination suffers the high Compton temperature of the plasma while the other two scenarios are not mutually exclusive and could account for the claimed iron line detected in two afterglows.

Davide Lazzati; Sergio Campana; Gabriele Ghisellini

1999-06-14

396

Adsorption of ammonia on multilayer iron phthalocyanine  

SciTech Connect

The adsorption of ammonia on multilayers of well-ordered, flat-lying iron phthalocyanine (FePc) molecules on a Au(111) support was investigated by x-ray photoelectron spectroscopy. We find that the electron-donating ammonia molecules coordinate to the metal centers of iron phthlalocyanine. The coordination of ammonia induces changes of the electronic structure of the iron phthalocyanine layer, which, in particular, lead to a modification of the FePc valence electron spin.

Isvoranu, Cristina; Knudsen, Jan; Ataman, Evren; Andersen, Jesper N.; Schnadt, Joachim [Division of Synchrotron Radiation Research, Department of Physics, Lund University, Box 118, 221 00 Lund (Sweden); Schulte, Karina [MAX-lab, Lund University, Box 118, 221 00 Lund (Sweden); Wang Bin; Bocquet, Marie-Laure [Laboratoire de chimie, Ecole normale superieure de Lyon, 46, Allee d'Italie, 69364 Lyon Cedex 07 (France)

2011-03-21

397

Producing Iron Nuggets with Steel Making Wastes  

Microsoft Academic Search

A new process to recycle the iron and carbon from steel making wastes is proposed in this paper. We produce iron nuggets at high temperature by direct reduction with basic synthetic steel making wastes briquette or pellet has been introduced, in which the main factors of effecting iron nuggets separating from slag have been researched. The 2CaO·SiO2 of slag changed

Wei Wang; Zhengliang Xue; Guojun Ma; Hong Xiao; Xiuying Guo; Lingzhi Xing

2010-01-01

398

Surface modification of high temperature iron alloys  

DOEpatents

A method and article of manufacture of a coated iron based alloy. The method includes providing an iron based alloy substrate, depositing a silicon containing layer on the alloy surface while maintaining the alloy at a temperature of about 700.degree. C.-1200.degree. C. to diffuse silicon into the alloy surface and exposing the alloy surface to an ammonia atmosphere to form a silicon/oxygen/nitrogen containing protective layer on the iron based alloy.

Park, Jong-Hee (Clarendon Hills, IL)

1995-01-01

399

Study of iron mononitride thin films  

SciTech Connect

In this work we have studied the crystal structural and local ordering of iron and nitrogen in iron mononitride thin films prepared using dc magnetron sputtering at sputtering power of 100W and 500W. The films were sputtered using pure nitrogen to enhance the reactivity of nitrogen with iron. The x-ray diffraction (XRD), conversion electron Mössbauer spectroscopy (CEMS) and soft x-ray absorption spectroscopy (SXAS) studies shows that the film crystallizes in ZnS-type crystal structure.

Tayal, Akhil, E-mail: mgupta@csr.res.in; Gupta, Mukul, E-mail: mgupta@csr.res.in; Phase, D. M., E-mail: mgupta@csr.res.in; Reddy, V. R., E-mail: mgupta@csr.res.in; Gupta, Ajay, E-mail: mgupta@csr.res.in [UGC-DAE Consortium for Scientific Research, University Campus, Khandwa Road, Indore,-452001 (India)

2014-04-24

400

Surface modification of high temperature iron alloys  

DOEpatents

A method and article of manufacture of a coated iron based alloy are disclosed. The method includes providing an iron based alloy substrate, depositing a silicon containing layer on the alloy surface while maintaining the alloy at a temperature of about 700--1200 C to diffuse silicon into the alloy surface and exposing the alloy surface to an ammonia atmosphere to form a silicon/oxygen/nitrogen containing protective layer on the iron based alloy. 13 figs.

Park, J.H.

1995-06-06

401

Study of iron mononitride thin films  

NASA Astrophysics Data System (ADS)

In this work we have studied the crystal structural and local ordering of iron and nitrogen in iron mononitride thin films prepared using dc magnetron sputtering at sputtering power of 100W and 500W. The films were sputtered using pure nitrogen to enhance the reactivity of nitrogen with iron. The x-ray diffraction (XRD), conversion electron Mössbauer spectroscopy (CEMS) and soft x-ray absorption spectroscopy (SXAS) studies shows that the film crystallizes in ZnS-type crystal structure.

Tayal, Akhil; Gupta, Mukul; Phase, D. M.; Reddy, V. R.; Gupta, Ajay

2014-04-01

402

Effect of Iron Injections on Aerobic-Exercise Performance of Iron-Depleted Female Athletes  

Microsoft Academic Search

This investigation examined the effect of intramuscular iron injections on aerobic-exercise performance in iron-deficient women. Sixteen athletes performed a 10-min steady-state submaximal economy test, a VO2max test, and a timed test to exhaustion at VO2max workload. Subjects were randomly assigned to an iron-supplemented group (IG) receiving intramuscular iron injections or to a placebo group (PG). Twenty days after the first

Peter Peeling; Tanya Blee; Carmel Goodman; Brian Dawson; Gary Claydon; John Beilby; Alex Prins

2007-01-01

403

Hemoglobin, Packed Cell Volume, Serum Iron and Iron Binding Capacity of Selected Athletes During Training  

Microsoft Academic Search

Hematological findings obtained by screening topathletes during training in The Neterlands reveal an occurrence of iron-deficient anemia of 2% in male and 2.5% in female athletes. In addition, 3% of the athletes have mild anemia without signs of iron depletion. Moreover, iron depletion without anemia as well as latent iron deficiency without anemia was present in 3, respectively 5% of

J. F. de Wijn; J. L. de Jongste; W. Mosterd; D. Willebrand

1971-01-01

404

Secreted Pyomelanin of Legionella pneumophila Promotes Bacterial Iron Uptake and Growth under Iron-Limiting Conditions  

PubMed Central

Iron acquisition is critical to the growth and virulence of Legionella pneumophila. Previously, we found that L. pneumophila uses both a ferrisiderophore pathway and ferrous iron transport to obtain iron. We now report that two molecules secreted by L. pneumophila, homogentisic acid (HGA) and its polymerized variant (HGA-melanin, a pyomelanin), are able to directly mediate the reduction of various ferric iron salts. Furthermore, HGA, synthetic HGA-melanin, and HGA-melanin derived from bacterial supernatants enhanced the ability of L. pneumophila and other species of Legionella to take up radiolabeled iron. Enhanced iron uptake was not observed with a ferrous iron transport mutant. Thus, HGA and HGA-melanin mediate ferric iron reduction, with the resulting ferrous iron being available to the bacterium for uptake. Upon further testing of L. pneumophila culture supernatants, we found that significant amounts of ferric and ferrous iron were associated with secreted HGA-melanin. Importantly, a pyomelanin-containing fraction obtained from a wild-type culture supernatant was able to stimulate the growth of iron-starved legionellae. That the corresponding supernatant fraction obtained from a nonpigmented mutant culture did not stimulate growth demonstrated that HGA-melanin is able to both promote iron uptake and enhance growth under iron-limiting conditions. Indicative of a complementary role in iron acquisition, HGA-melanin levels were inversely related to the levels of siderophore activity. Compatible with a role in the ecology and pathogenesis of L. pneumophila, HGA and HGA-melanin were effective at reducing and releasing iron from both insoluble ferric hydroxide and the mammalian iron chelates ferritin and transferrin. PMID:23980114

Zheng, Huaixin; Chatfield, Christa H.; Liles, Mark R.

2013-01-01

405

Impact of Oral Iron Challenges on Circulating Non-Transferrin-Bound Iron in Healthy Guatemalan Males  

Microsoft Academic Search

Introduction: Oral iron as a supplement has been associated with adverse health consequences, especially in the context of young children with active malaria. A potential aggravating role of non-transferrin-bound iron (NTBI) has been proposed. Material and Methods: NTBI responses in both a fasting and post-oral iron dosing situation were related to serum iron concentration and ferritin status. Fasting and 1,

Klaus Schümann; Sylvia Kroll; Maria-Eugenia Romero-Abal; Niki A. Georgiou; Jo J. M. Marx; Günter Weiss; Noel W. Solomons

2012-01-01

406

Bone marrow iron in nutritional anaemias.  

PubMed

Bone marrow smears of 168 patients with nutritional anaemias attending the Dr. J.C. Patel, Department of Hematology, K.E.M. Hospital were stained by Prussian blue method for iron (haemosiderin). Iron in the bone marrow was classified as absent, decreased, normal or increased. Amongst 93 cases with transferrin saturation (TS) of less than 16% and normoblastic erythropoiesis, bone marrow iron was absent in 48 (51.6%) and decreased in 45 (48.4%). In 50 cases with TS of less than 16% and marrow showing megaloblasts and/or giant myelocytes and metamyelocytes, bone marrow iron was absent in 15 (30%), decreased in 22 (44%), normal in 7 (14%) and increased in 6 (12%). In 25 cases with TS over 16% and megaloblastic erythropoiesis, bone marrow iron was absent in 4 (16%), decreased in 1 (4%), normal in 7 (28%) and increased in 13 (52%). In 150 (89.3%) patients out of 168, bone marrow iron and TS gave concordant results whereas in 18 (10.7%), the results were discordant; former was encountered in cases of uncomplicated iron deficiency while latter was found with megaloblastic morphology of the marrow. It is concluded that there is a good correlation between TS and bone marrow iron and hence, either of the criteria can be used for the diagnosis of iron deficiency especially when it is not complicated by megaloblastosis. PMID:2632529

Mehta, B C; Pandya, B G

1989-11-01

407

Iron in neuronal function and dysfunction.  

PubMed

Iron (Fe) is an essential element for many metabolic processes, serving as a cofactor for heme and nonheme proteins. Cellular iron deficiency arrests cell growth and leads to cell death; however, like most transition metals, an excess of intracellular iron is toxic. The ability of Fe to accept and donate electrons can lead to the formation of reactive nitrogen and oxygen species, and oxidative damage to tissue components; contributing to disease and, perhaps, aging itself. It has also been suggested that iron-induced oxidative stress can play a key role in the pathogenesis of several neurodegenerative diseases. Iron progressively accumulates in the brain both during normal aging and neurodegenerative processes. However, iron accumulation occurs without the concomitant increase in tissue ferritin, which could increase the risk of oxidative stress. Moreover, high iron concentrations in the brain have been consistently observed in Alzheimer's disease (AD) and Parkinson's disease (PD). In this regard, metalloneurobiology has become extremely important in understanding the role of iron in the onset and progression of neurodegenerative diseases. Neurons have developed several protective mechanisms against oxidative stress, among them the activation of cellular signaling pathways. The final response will depend on the identity, intensity, and persistence of the oxidative insult. The characterization of the mechanisms involved in high iron induced in neuronal dysfunction and death is central to understanding the pathology of a number of neurodegenerative disorders. PMID:20232345

Salvador, Gabriela A

2010-01-01

408

Systemic iron distribution during hemochromatosis and inflammation.  

E-print Network

??Juvenile hemochromatosis (JH), anemia of chronic disease (ACD) and various inflammatory conditions such as Hepatitis C and alcoholic steatohepatitis exhibit improper handling of systemic iron.… (more)

Andriopoulos, Bill

2008-01-01

409

Iron oxyhydroxide mineralization on microbial extracellular polysaccharides  

SciTech Connect

Iron biominerals can form in neutral pH microaerophilic environments where microbes both catalyze iron oxidation and create polymers that localize mineral precipitation. In order to classify the microbial polymers that influence FeOOH mineralogy, we studied the organic and mineral components of biominerals using scanning transmission X-ray microscopy (STXM), micro X-ray fluorescence ({mu}XRF) microscopy, and high-resolution transmission electron microscopy (HRTEM). We focused on iron microbial mat samples from a creek and abandoned mine; these samples are dominated by iron oxyhydroxide-coated structures with sheath, stalk, and filament morphologies. In addition, we characterized the mineralized products of an iron-oxidizing, stalk-forming bacterial culture isolated from the mine. In both natural and cultured samples, microbial polymers were found to be acidic polysaccharides with carboxyl functional groups, strongly spatially correlated with iron oxyhydroxide distribution patterns. Organic fibrils collect FeOOH and control its recrystallization, in some cases resulting in oriented crystals with high aspect ratios. The impact of polymers is particularly pronounced as the materials age. Synthesis experiments designed to mimic the biomineralization processes show that the polysaccharide carboxyl groups bind dissolved iron strongly but release it as mineralization proceeds. Our results suggest that carboxyl groups of acidic polysaccharides are produced by different microorganisms to create a wide range of iron oxyhydroxide biomineral structures. The intimate and potentially long-term association controls the crystal growth, phase, and reactivity of iron oxyhydroxide nanoparticles in natural systems.

Chan, Clara S.; Fakra, Sirine C.; Edwards, David C.; Emerson, David; Banfield, Jillian F.

2010-06-22

410

Ferrous iron transport in Streptococcus mutans  

SciTech Connect

Radioiron uptake from /sup 59/FeCl/sub 3/ by Streptococcus mutans OMZ176 was increased by anaerobiosis, sodium ascorbate, and phenazine methosulfate (PMS), although there was a 10-min lag before PMS stimulation was evident. The reductant ascorbate may have provided ferrous iron. The PMS was reduced by the cells, and the reduced PMS then may have generated ferrous iron for transport; reduced PMS also may have depleted dissolved oxygen. It was concluded that S. mutans transports only ferrous iron, utilizing reductants furnished by glucose metabolism to reduce iron prior to its uptake.

Evans, S.L.; Arcenaeux, J.E.L.; Byers, B.R.; Martin, M.E.; Aranha, H.

1986-12-01

411

Biosynthesis and characterization of layered iron phosphate  

NASA Astrophysics Data System (ADS)

Layered iron phosphate with uniform morphology has been synthesized by a precipitation method with yeast cells as a biosurfactant. The yeast cells are used to regulate the nucleation and growth of layered iron phosphate. The uniform layered structure is characterized by small-angle x-ray diffraction (SAXD), scanning electron microscopy (SEM) and atomic force microscopy (AFM) analyses. Fourier transform infrared spectroscopy (FT-IR) is used to analyze the chemical bond linkages in organic-inorganic hybrid iron phosphate. The likely synthetic mechanism of nucleation and oriented growth is discussed. The electrical conductivity of hybrid iron phosphate heat-treated at different temperatures is presented.

Zhou, Weijia; He, Wen; Wang, Meiting; Zhang, Xudong; Li, Peng; Yan, Shunpu; Tian, Xiuying; Sun, Xianan; Han, Xiuxiu

2008-12-01

412

Method for producing iron-based catalysts  

DOEpatents

A method for preparing an acid catalyst having a long shelf-life is provided comprising doping crystalline iron oxides with lattice-compatible metals and heating the now-doped oxide with halogen compounds at elevated temperatures. The invention also provides for a catalyst comprising an iron oxide particle having a predetermined lattice structure, one or more metal dopants for said iron oxide, said dopants having an ionic radius compatible with said lattice structure; and a halogen bound with the iron and the metal dopants on the surface of the particle.

Farcasiu, Malvina (Pittsburgh, PA); Kaufman, Phillip B. (Library, PA); Diehl, J. Rodney (Pittsburgh, PA); Kathrein, Hendrik (McMurray, PA)

1999-01-01

413

Iron hypothesis of cardiovascular disease: still controversial.  

PubMed

Iron hypothesis has been a controversial subject for over 30 years as many studies support its role as a risk factor for cardiovascular disease, while other studies found no evidence to support it. The conflicting results are accounted for by the non-homogeneity of trial design in terms of population inclusion criteria and different endpoints, non-uniform use of parameters for assessing iron role, and incomplete understanding of the mechanisms of action. The nature of iron is dual, being of crucial importance for the human body, but also toxic as "free iron" induces oxidative stress. Under physiological conditions, there are efficient and complex mechanisms against iron-induced oxidative stress, which could be reproduced for creating new, intelligent antioxidants. Iron depletion improves the cardiovascular prognosis only if serum concentration is at the lowest limit of normal ranges. However, low iron levels and the type of dietary iron intake correlate with atherosclerotic cardiovascular disease, influence the ischemic endpoints in the elderly, and exert negative impact on heart failure prognosis. So far, the causal relation and involved mechanisms are not fully elucidated. Iron overload is a difficult and frequent condition, involving the cardiovascular system by specific pathogenic pathways, therefore determining a particular form of restrictive cardiomyopathy and vaso-occlusive arterial damage. PMID:25581946

Aursulesei, Viviana; Cozma, A; Krasniqi, A

2014-01-01

414

Iron accumulation in lung allografts after transplantation.  

PubMed

Lung transplantation has become a therapeutic option for end-stage pulmonary diseases, but after transplantation, infections and obliterative bronchiolitis (OB) are major causes of long-term morbidity and mortality. OB is a fibroproliferative disease, of poorly understood etiology, characterized by an irreversible decline in allograft function. Because diseases with tissue iron overload are characterized by fibrosis and end-organ failure, we studied the iron concentrations in BAL fluid and lung tissue in 10 lung allograft patients. BAL fluid revealed significantly elevated iron concentrations in allograft patients compared with five normal volunteers (135+/-16.54 micromol/L vs 33.65+/-7.48 micromol/L, respectively). Prussian blue staining of biopsy specimens of lung allograft tissue revealed an accumulation of iron primarily in alveolar macrophages. Immunohistochemical stains for ferritin revealed accumulation of the protein in macrophages, interstitium, vascular walls, and bronchiolar epithelium. Iron studies of the blood (serum ferritin and iron concentrations) revealed no evidence for systemic iron overload. In conclusion, patients with pulmonary allografts appear to have elevated concentrations of iron in lung tissue. This iron overload may place the allografts at increased risk of metal-mediated injury and fibrosis. PMID:9266881

Baz, M A; Ghio, A J; Roggli, V L; Tapson, V F; Piantadosi, C A

1997-08-01

415

The girl with the iron tattoo.  

PubMed

We describe a young woman with profound anemia whose serum iron studies were incongruous with what we expected from iron deficiency anemia. Her high serum iron was not fully explainable until we examined the patient and noticed a large black tattoo on her left flank area. Apparently iron oxide in the ink used for the tattoo was absorbed transcutaneously and led to high serum iron in the face of the other data, which suggested iron deficiency. She was slow in mobilizing her serum iron for erythropoiesis and we discovered that there was a concurrent acute B19 parvovirus infection, which impeded utilization of the iron for red blood cell production. We believe that this case report reinforces the imperative to always do a careful physical examination with any patient who has anemia, and also illustrates the potential toxicity of tattoo ink. The impairment of utilization of the serum iron because of the patient's acute B19 parvovirus infection demonstrates the many consequences of infection induced aplastic anemia. PMID:23076330

Fircanis, Sophia; Shields, Reve; Castillo, Jorge; Mega, Anthony; Schiffman, Fred

2012-11-15

416

The girl with the iron tattoo  

PubMed Central

We describe a young woman with profound anemia whose serum iron studies were incongruous with what we expected from iron deficiency anemia. Her high serum iron was not fully explainable until we examined the patient and noticed a large black tattoo on her left flank area. Apparently iron oxide in the ink used for the tattoo was absorbed transcutaneously and led to high serum iron in the face of the other data, which suggested iron deficiency. She was slow in mobilizing her serum iron for erythropoiesis and we discovered that there was a concurrent acute B19 parvovirus infection, which impeded utilization of the iron for red blood cell production. We believe that this case report reinforces the imperative to always do a careful physical examination with any patient who has anemia, and also illustrates the potential toxicity of tattoo ink. The impairment of utilization of the serum iron because of the patient's acute B19 parvovirus infection demonstrates the many consequences of infection induced aplastic anemia. PMID:23076330

Fircanis, Sophia; Shields, Reve; Castillo, Jorge; Mega, Anthony; Schiffman, Fred

2012-01-01

417

Increased corrosion resistance of chromium-coated armco iron by ion-beam mixing  

NASA Astrophysics Data System (ADS)

The corrosion resistance of Armco iron coated with a thin layer of chromium is found to be significantly increased by ion-beam mixing with argon ions. The optimal dose for corrosion resistance is the same as that found for tribological properties, 2.4 × 10 16 cm -2, further implantation destroying the integrity of the surface by the formation of argon bubbles which appear to encourage pitting. The overall electrochemical behaviour at the optimal dose is comparable to that of Fe-18Cr alloy and of direct implantation of chromium ions into vacuum-melted electrolytic iron.

Larouche, Bernard; Adnot, Alain; Knystautas, Emile J.

1989-04-01

418

Obesity Alters Adipose Tissue Macrophage Iron Content and Tissue Iron Distribution  

PubMed Central

Adipose tissue (AT) expansion is accompanied by the infiltration and accumulation of AT macrophages (ATMs), as well as a shift in ATM polarization. Several studies have implicated recruited M1 ATMs in the metabolic consequences of obesity; however, little is known regarding the role of alternatively activated resident M2 ATMs in AT homeostasis or how their function is altered in obesity. Herein, we report the discovery of a population of alternatively activated ATMs with elevated cellular iron content and an iron-recycling gene expression profile. These iron-rich ATMs are referred to as MFehi, and the remaining ATMs are referred to as MFelo. In lean mice, ~25% of the ATMs are MFehi; this percentage decreases in obesity owing to the recruitment of MFelo macrophages. Similar to MFelo cells, MFehi ATMs undergo an inflammatory shift in obesity. In vivo, obesity reduces the iron content of MFehi ATMs and the gene expression of iron importers as well as the iron exporter, ferroportin, suggesting an impaired ability to handle iron. In vitro, exposure of primary peritoneal macrophages to saturated fatty acids also alters iron metabolism gene expression. Finally, the impaired MFehi iron handling coincides with adipocyte iron overload in obese mice. In conclusion, in obesity, iron distribution is altered both at the cellular and tissue levels, with AT playing a predominant role in this change. An increased availability of fatty acids during obesity may contribute to the observed changes in MFehi ATM phenotype and their reduced capacity to handle iron. PMID:24130337

Orr, Jeb S.; Kennedy, Arion; Anderson-Baucum, Emily K.; Webb, Corey D.; Fordahl, Steve C.; Erikson, Keith M.; Zhang, Yaofang; Etzerodt, Anders; Moestrup, Søren K.; Hasty, Alyssa H.

2014-01-01

419

Modeling Red Blood Cell and Iron Dynamics in Patients Undergoing Periodic EPO and Iron Treatments  

E-print Network

Modeling Red Blood Cell and Iron Dynamics in Patients Undergoing Periodic EPO and Iron Treatments H in the kidneys, that stimulates red blood cell (RBC) production. Without intervention, patients suffer from, erythrocyte, red blood cell, chronic kidney disease, dialysis, iron, neocytolysis, hepcidin, EPO, hemoglobin e

420

Low hepatic iron concentration: evaluation of two complementary methods, colorimetric assay and iron histological scoring  

Microsoft Academic Search

AIMS: To validate a method of assessment of low hepatic iron concentration based on a biochemical colorimetric assay plus histological scoring. METHODS: The within-day and day to day precision of the iron colorimetric assay was determined on frozen rat liver. The coefficient of variation (CV) of iron measurement in two separate samples from the same liver was determined for 21

F. Imbert-Bismut; F. Charlotte; B. Turlin; L. Khalil; A. Piton; P. Brissot; Y. Le Charpentier; J. Delattre; P. Opolon; Y. Deugnier; T. Poynard

1999-01-01

421

The distribution of iron in the brain: A phylogenetic analysis using iron histochemistry  

Microsoft Academic Search

Histochemical procedures can be used to detect the cellular distribution of iron in the brain. The objective of the present study was to determine if the cellular distribution of iron enrichment is conserved between animals on different branches of the phylogenetic tree. This information can facilitate our understanding of the role of iron enrichment in cells of the brain. The

Gregory L. Erb; David L. Osterbur; Steven M. LeVine

1996-01-01

422

Combined Therapy of Iron Chelator and Antioxidant Completely Restores Brain Dysfunction Induced by Iron Toxicity  

PubMed Central

Background Excessive iron accumulation leads to iron toxicity in the brain; however the underlying mechanism is unclear. We investigated the effects of iron overload induced by high iron-diet consumption on brain mitochondrial function, brain synaptic plasticity and learning and memory. Iron chelator (deferiprone) and antioxidant (n-acetyl cysteine) effects on iron-overload brains were also studied. Methodology Male Wistar rats were fed either normal diet or high iron-diet consumption for 12 weeks, after which rats in each diet group were treated with vehicle or deferiprone (50 mg/kg) or n-acetyl cysteine (100 mg/kg) or both for another 4 weeks. High iron-diet consumption caused brain iron accumulation, brain mitochondrial dysfunction, impaired brain synaptic plasticity and cognition, blood-brain-barrier breakdown, and brain apoptosis. Although both iron chelator and antioxidant attenuated these deleterious effects, combined therapy provided more robust results. Conclusion In conclusion, this is the first study demonstrating that combined iron chelator and anti-oxidant therapy completely restored brain function impaired by iron overload. PMID:24400127

Sripetchwandee, Jirapas; Pipatpiboon, Noppamas; Chattipakorn, Nipon; Chattipakorn, Siriporn

2014-01-01

423

Bordetella pertussis FbpA binds both unchelated iron and iron siderophore complexes.  

PubMed

Bordetella pertussis is the causative agent of whooping cough. This pathogenic bacterium can obtain the essential nutrient iron using its native alcaligin siderophore and by utilizing xeno-siderophores such as desferrioxamine B, ferrichrome, and enterobactin. Previous genome-wide expression profiling identified an iron repressible B. pertussis gene encoding a periplasmic protein (FbpABp). A previously reported crystal structure shows significant similarity between FbpABp and previously characterized bacterial iron binding proteins, and established its iron-binding ability. Bordetella growth studies determined that FbpABp was required for utilization of not only unchelated iron, but also utilization of iron bound to both native and xeno-siderophores. In this in vitro solution study, we quantified the binding of unchelated ferric iron to FbpABp in the presence of various anions and importantly, we demonstrated that FbpABp binds all the ferric siderophores tested (native and xeno) with ?M affinity. In silico modeling augmented solution data. FbpABp was incapable of iron removal from ferric xeno-siderophores in vitro. However, when FbpABp was reacted with native ferric-alcaligin, it elicited a pronounced change in the iron coordination environment, which may signify an early step in FbpABp-mediated iron removal from the native siderophore. To our knowledge, this is the first time the periplasmic component of an iron uptake system has been shown to bind iron directly as Fe(3+) and indirectly as a ferric siderophore complex. PMID:24873326

Banerjee, Sambuddha; Weerasinghe, Aruna J; Parker Siburt, Claire J; Kreulen, R Timothy; Armstrong, Sandra K; Brickman, Timothy J; Lambert, Lisa A; Crumbliss, Alvin L

2014-06-24

424

Evolution integrals  

E-print Network

A framework analogous to path integrals in quantum physics is set up for abstract dynamical systems in a W*-algebraic setting. We consider spaces of evolutions, defined in a specific way, of a W*-algebra A as an analogue of spaces of classical paths, and show how integrals over such spaces, which we call ``evolution integrals'', lead to dynamics in a Hilbert space on a ``higher level'' which is viewed as an analogue of quantum dynamics obtained from path integrals. The measures with respect to which these integrals are performed are projection valued.

Rocco Duvenhage

2006-05-24

425

Electrodynamics in Iron and Steel  

E-print Network

In order to calculate the reflected EM fields at low amplitudes in iron and steel, more must be understood about the nature of long wavelength excitations in these metals. A bulk piece of iron is a very complex material with microstructure, a split band structure, magnetic domains and crystallographic textures that affect domain orientation. Probing iron and other bulk ferromagnetic materials with weak reflected and transmitted inductive low frequency fields is an easy operation to perform but the responses are difficult to interpret because of the complexity and variety of the structures affected by the fields. First starting with a simple single coil induction measurement and classical EM calculation to show the error is grossly under estimating the measured response. Extending this experiment to measuring the transmission of the induced fields allows the extraction of three dispersion curves which define these internal fields. One dispersion curve yielded an exceedingly small effective mass of 1.8 10^{-39}kg (1.3 10^{-9} m_e) for those spin waves. There is a second distinct dispersion curve more representative of the density function of a zero momentum bound state rather than a propagating wave. The third dispersion curve describes a magneto-elastic coupling to a very long wave length propagating mode. These experiments taken together display the characteristics of a high temperature Bose-Einstein like condensation that can be initiated by pumping two different states. A weak time dependent field drives the formation of coupled J=0 spin wave pairs with the reduced effective mass reflecting the increased size of the coherent state. These field can dominate induction measurements well past the Curie temperature.

John Paul Wallace

2009-06-03

426

39. Detail view of No. 2 Furnace iron runner; rod ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

39. Detail view of No. 2 Furnace iron runner; rod or poker at right was used to unplug iron notch. - Sloss-Sheffield Steel & Iron, First Avenue North Viaduct at Thirty-second Street, Birmingham, Jefferson County, AL

427

21 CFR 573.580 - Iron-choline citrate complex.  

Code of Federal Regulations, 2013 CFR

... 6 2013-04-01 2013-04-01 false Iron-choline citrate complex. 573.580 Section...ANIMALS Food Additive Listing § 573.580 Iron-choline citrate complex. Iron-choline citrate complex made by reacting...

2013-04-01

428

49 CFR 236.532 - Strap iron inductor; use restricted.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Strap iron inductor; use restricted. 236.532...Instructions; Roadway § 236.532 Strap iron inductor; use restricted. No railroad shall use strap iron inductor or other roadway element...

2013-10-01

429

40 CFR 721.10357 - Iron, citrate phosphate potassium complexes.  

...2014-07-01 2014-07-01 false Iron, citrate phosphate potassium complexes...Specific Chemical Substances § 721.10357 Iron, citrate phosphate potassium complexes...1) The chemical substance identified as iron, citrate phosphate potassium...

2014-07-01

430

40 CFR 721.10357 - Iron, citrate phosphate potassium complexes.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Iron, citrate phosphate potassium complexes...Specific Chemical Substances § 721.10357 Iron, citrate phosphate potassium complexes...1) The chemical substance identified as iron, citrate phosphate potassium...

2012-07-01

431

21 CFR 172.370 - Iron-choline citrate complex.  

Code of Federal Regulations, 2011 CFR

... 3 2011-04-01 2011-04-01 false Iron-choline citrate complex. 172.370 Section...Dietary and Nutritional Additives § 172.370 Iron-choline citrate complex. Iron-choline citrate complex made by reacting...

2011-04-01

432

21 CFR 172.370 - Iron-choline citrate complex.  

... 3 2014-04-01 2014-04-01 false Iron-choline citrate complex. 172.370 Section...Dietary and Nutritional Additives § 172.370 Iron-choline citrate complex. Iron-choline citrate complex made by reacting...

2014-04-01

433

49 CFR 236.532 - Strap iron inductor; use restricted.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Strap iron inductor; use restricted. 236.532...Instructions; Roadway § 236.532 Strap iron inductor; use restricted. No railroad shall use strap iron inductor or other roadway element...

2012-10-01

434

21 CFR 573.580 - Iron-choline citrate complex.  

Code of Federal Regulations, 2011 CFR

... 6 2011-04-01 2011-04-01 false Iron-choline citrate complex. 573.580 Section...ANIMALS Food Additive Listing § 573.580 Iron-choline citrate complex. Iron-choline citrate complex made by reacting...

2011-04-01

435

21 CFR 573.580 - Iron-choline citrate complex.  

Code of Federal Regulations, 2010 CFR

... 6 2010-04-01 2010-04-01 false Iron-choline citrate complex. 573.580 Section...ANIMALS Food Additive Listing § 573.580 Iron-choline citrate complex. Iron-choline citrate complex made by reacting...

2010-04-01

436

49 CFR 236.532 - Strap iron inductor; use restricted.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Strap iron inductor; use restricted. 236.532...Instructions; Roadway § 236.532 Strap iron inductor; use restricted. No railroad shall use strap iron inductor or other roadway element...

2011-10-01

437

21 CFR 573.580 - Iron-choline citrate complex.  

... 6 2014-04-01 2014-04-01 false Iron-choline citrate complex. 573.580 Section...ANIMALS Food Additive Listing § 573.580 Iron-choline citrate complex. Iron-choline citrate complex made by reacting...

2014-04-01

438

40 CFR 721.10357 - Iron, citrate phosphate potassium complexes.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Iron, citrate phosphate potassium complexes...Specific Chemical Substances § 721.10357 Iron, citrate phosphate potassium complexes...1) The chemical substance identified as iron, citrate phosphate potassium...

2013-07-01

439

49 CFR 236.532 - Strap iron inductor; use restricted.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Strap iron inductor; use restricted. 236.532...Instructions; Roadway § 236.532 Strap iron inductor; use restricted. No railroad shall use strap iron inductor or other roadway element...

2010-10-01

440

21 CFR 172.370 - Iron-choline citrate complex.  

Code of Federal Regulations, 2012 CFR

... 3 2012-04-01 2012-04-01 false Iron-choline citrate complex. 172.370 Section...Dietary and Nutritional Additives § 172.370 Iron-choline citrate complex. Iron-choline citrate complex made by reacting...

2012-04-01

441

21 CFR 172.370 - Iron-choline citrate complex.  

Code of Federal Regulations, 2010 CFR

... 3 2010-04-01 2009-04-01 true Iron-choline citrate complex. 172.370 Section...Dietary and Nutritional Additives § 172.370 Iron-choline citrate complex. Iron-choline citrate complex made by reacting...

2010-04-01

442

21 CFR 172.370 - Iron-choline citrate complex.  

Code of Federal Regulations, 2013 CFR

... 3 2013-04-01 2013-04-01 false Iron-choline citrate complex. 172.370 Section...Dietary and Nutritional Additives § 172.370 Iron-choline citrate complex. Iron-choline citrate complex made by reacting...

2013-04-01

443

21 CFR 573.580 - Iron-choline citrate complex.  

Code of Federal Regulations, 2012 CFR

... 6 2012-04-01 2012-04-01 false Iron-choline citrate complex. 573.580 Section...ANIMALS Food Additive Listing § 573.580 Iron-choline citrate complex. Iron-choline citrate complex made by reacting...

2012-04-01

444

20. INTERIOR VIEW WITH IRON POURERS FILLING COMPLETED MOLDS ON ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

20. INTERIOR VIEW WITH IRON POURERS FILLING COMPLETED MOLDS ON GREY IRON UNIT NO. 1 MOLD CONVEYOR. - Stockham Pipe & Fittings Company, Grey Iron Foundry, 4000 Tenth Avenue North, Birmingham, Jefferson County, AL

445

19. INTERIOR VIEW WITH IRON POURERS FILLING COMPLETED MOLDS ON ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

19. INTERIOR VIEW WITH IRON POURERS FILLING COMPLETED MOLDS ON GREY IRON UNIT NO. 1 MOLD CONVEYOR. - Stockham Pipe & Fittings Company, Grey Iron Foundry, 4000 Tenth Avenue North, Birmingham, Jefferson County, AL

446

Iron Catalyzed Aminohydroxylation of Olefins  

PubMed Central

We have discovered that N-sulfonyl oxaziridines react with a broad range of olefins in the presence of iron salts to afford 1,3-oxazolidines. This process provides access to 1,2-aminoalcohols with the opposite sense of regioselectivity produced from the copper-catalyzed oxyamination previously reported from our labs. Thus, either regioisomeric form of 1,2-aminoalcohols can easily be obtained from the reaction of oxaziridines with olefins, and the sense of regioselectivity can be controlled by the appropriate choice of inexpensive, non-toxic first row transition metal catalyst. PMID:20232850

Williamson, Kevin S.; Yoon, Tehshik P.

2010-01-01

447

Plant mechanisms of siderophore-iron utilization  

SciTech Connect

Mechanisms of siderophore iron-utilization by plants were examined to determine whether plants have direct mechanisms for acquiring iron from microbially-produced hydroxamate siderophores or simply take up inorganic iron in equilibrium with the chelate (shuttle mechanism). Experiments were designed to determine whether the monocot plant species, oat (Avena sativa L. cv. Victory) could acquire iron from ferrichrome under hydroponic conditions in which iron uptake was most likely to occur by direct use of the chelating agent. Ten-day-old iron-deficient seedlings, grown in aerated Hoagland's nutrient solution (minus iron) buffered at pH 7.4 with CaCO/sub 3/, were placed in fresh nutrient solution containing 10/sup -7.4/M radioactive /sup 55/FeCl/sub 3/ (23.7 mCi/mg) with the synthetic chelate, EDDHA (10..pi../sup 5/M), ferrichrome (10/sup -5/M), or with no chelate. After 6 days, shoot content of /sup 55/Fe in shoots of plants provided with ferrichrome was 100-fold greater than that in shoots of plants provided with EDDHA. Therefore iron uptake by oat under these conditions not only indicates direct use of ferrichrome, but also suggest that oat may be better able to acquire iron from siderophores than from synthetic chelates. One possible mechanism for direct use of chelating agents, may involve siderophore binding sites on the plasmalemma of root cortical cells where iron is split from the chelate by enzymatic reduction of ferric to ferrous iron. To demonstrate hypothesized siderophore binding sites on oat roots, experiments examined possible competition for presumed siderophore binding sites by an inert analog of ferrichrome constructed by irreversible chelation with chromium.

Crowley, D.E.

1986-01-01

448

Hepatic Iron Overload and Hepatocellular Carcinoma  

PubMed Central

In recent years it has become increasingly evident that excess body iron may be complicated by the supervention of hepatocellular carcinoma (HCC). Hereditary hemochromatosis (HH) was the first condition in which hepatic iron overload was shown to predispose to the development of HCC. The inherited predisposition to excessive absorption of dietary iron in HH is almost always the result of homozygosity of the C282Y mutation of the HFE gene, which causes inappropriately low secretion of hepcidin. HCC develops in 8-10% of patients with HH and is responsible for approximately 45% of deaths in the HCC patients. Cirrhosis is almost always present when HCC is diagnosed. Dietary iron overload is a condition which occurs in rural-dwelling Black Africans in southern Africa as a result of the consumption, over time, of large volumes of alcohol home-brewed in iron containers and having, as a consequence, a high iron content. Iron loading of the liver results and may be complicated by malignant transformation of the liver (relative risk of approximately 10.0). Accompanying cirrhosis does occur but is less common than that in HH. The development of HCC as a consequence of increased dietary iron, and the fact that it may develop in the absence of cirrhosis, has been confirmed in an animal model. Drinking water with a high iron content might contribute to the high incidence of HCC in parts of Taiwan. The metabolic syndrome [obesity, insulin resistance type 2 (or diabetes mellitus type 2), non-alcoholic fatty liver or non-alcoholic steatohepatitis] has in recent years become a major public health problem in some resource-rich countries. A link between excess body iron and insulin resistance or the metabolic syndrome has become apparent. The metabolic syndrome may be complicated by the supervention of HCC, and recent evidence suggests that increased body iron may contribute to this complication. PMID:24804175

Kew, Michael C.

2014-01-01

449

Iron and learning potential in childhood.  

PubMed Central

Cognitive function. There is reasonably good evidence that mental and motor developmental test scores are lower among infants with iron deficiency anemia. Although the research on cognitive function in iron deficient older children and adults is sparse and diverse, it suggests that there may be alterations in attentional processes associated with iron deficiency. Iron therapy has not yet been shown effective in completely correcting many of the observed disturbances. Although some aspects of cognitive function seem to change with iron therapy, lower developmental. I.Q., and achievement test scores have still been noted after treatment. The behavioral effects of iron-deficiency anemia may be due to changes in neurotransmission. However, the biochemical bases are not yet completely understood. Noncognitive disturbances. A variety of noncognitive alterations during infant developmental testing has also been observed, including failure to respond to test stimuli, short attention span, unhappiness, increased fearfulness, withdrawal from the examiner, and increased body tension. Exploratory analyses suggest that such behavioral abnormalities may account for poor developmental test performance in infants with iron deficiency anemia. These studies indicate the fruitfulness of examining noncognitive aspects of behavior such as affect, attention, and activity, in addition to specific cognitive processes. Activity and work capacity: There has been a steady accumulation of evidence that iron-deficiency anemia limits maximal physical performance, submaximal endurance, and spontaneous activity in the adult, resulting in diminished work productivity with attendant economic losses. The relative importance of central and peripheral mechanisms underlying these effects, the extent to which anemia or iron deficiency separate from anemia is responsible, and the counterpart in infants and children remain to be established. This essay has examined recent evidence from research on central nervous system biochemistry and from human studies that iron deficiency adversely affects behavior by impairing cognitive function, producing noncognitive disturbances, and limiting activity and work capacity. The body of research taken as a whole provides increasingly persuasive arguments for intensifying efforts to prevent and treat iron deficiency anemia. PMID:2698245

Lozoff, B.

1989-01-01

450

A Computational Model of Liver Iron Metabolism  

PubMed Central

Iron is essential for all known life due to its redox properties; however, these same properties can also lead to its toxicity in overload through the production of reactive oxygen species. Robust systemic and cellular control are required to maintain safe levels of iron, and the liver seems to be where this regulation is mainly located. Iron misregulation is implicated in many diseases, and as our understanding of iron metabolism improves, the list of iron-related disorders grows. Recent developments have resulted in greater knowledge of the fate of iron in the body and have led to a detailed map of its metabolism; however, a quantitative understanding at the systems level of how its components interact to produce tight regulation remains elusive. A mechanistic computational model of human liver iron metabolism, which includes the core regulatory components, is presented here. It was constructed based on known mechanisms of regulation and on their kinetic properties, obtained from several publications. The model was then quantitatively validated by comparing its results with previously published physiological data, and it is able to reproduce multiple experimental findings. A time course simulation following an oral dose of iron was compared to a clinical time course study and the simulation was found to recreate the dynamics and time scale of the systems response to iron challenge. A disease state simulation of haemochromatosis was created by altering a single reaction parameter that mimics a human haemochromatosis gene (HFE) mutation. The simulation provides a quantitative understanding of the liver iron overload that arises in this disease. This model supports and supplements understanding of the role of the liver as an iron sensor and provides a framework for further modelling, including simulations to identify valuable drug targets and design of experiments to improve further our knowledge of this system. PMID:24244122

Mitchell, Simon; Mendes, Pedro

2013-01-01

451

Transferrin saturation with intravenous irons: An in vitro study  

Microsoft Academic Search

Transferrin saturation with intravenous irons: An in vitro study.BackgroundIron deficiency anemia in chronic kidney disease is commonly treated with one of three intravenous irons—iron dextran, iron sucrose, or iron gluconate. Substantial pharmacologic differences between drugs exist, but their ability to saturate transferrin has not been compared. Drugs that may lead to rapid transferrin saturation may lead to greater efficacy but

RAJIV AGARWAL

2004-01-01

452

Iron Transport Machinery of Human Cells: Players and Their Interactions  

PubMed Central

Organisms, like cells, maintain tight control of iron. In humans as well as other mammals, control is achieved through the regulation of iron uptake into the body rather than through the excretion of iron. The mechanisms by which humans and mice regulate both iron uptake and the distribution of iron within the body and cells are reviewed. Special emphasis is given to the iron transporters involved in this process. PMID:23046647

Zhao, Ningning; Enns, Caroline A.

2014-01-01

453

Iron homeostasis in the fission yeast Schizosaccharomyces pombe  

Microsoft Academic Search

Schizosaccharomyces pombe has acquisition processes for iron, an essential nutrient. One pathway consists to produce, excrete, and capture siderophore–iron\\u000a complexes. A second pathway requires enzymatic reduction of ferric iron at the cell surface prior to uptake by a permease–oxidase\\u000a complex. Genes encoding proteins involved in iron assimilation are transcriptionally regulated as a function of iron availability.\\u000a Under high iron conditions,

Simon Labbé; Benoit Pelletier; Alexandre Mercier

2007-01-01

454

Iron absorption is more closely related to iron status than to daily iron intake in 12- to 48-mo-old children  

Technology Transfer Automated Retrieval System (TEKTRAN)

Few studies have evaluated iron absorption in small children after the first year of life. Our objective was to examine the relations among iron intake, iron absorption, and iron status in a group of healthy children. We studied 28 children, ages 12 to 48 mo, after a 7-d home adaptation to a diet re...

455

THE TISHOMINGO IRON: RELATIONSHIP TO IVB IRONS, CR CLAN CHONDRITES AND ANGRITES AND IMPLICATIONS FOR THE ORIGIN OF VOLATILE-DEPLETED IRON  

E-print Network

THE TISHOMINGO IRON: RELATIONSHIP TO IVB IRONS, CR CLAN CHONDRITES AND ANGRITES AND IMPLICATIONS FOR THE ORIGIN OF VOLATILE-DEPLETED IRON METEORITES. C.M. Corrigan1 , D. Rumble III2 , T.J. McCoy1 , R.D. Ash3 of Maryland, College Park, MD 20742 USA. Introduction: Of the ~1,000 known iron meteor- ites, ~85% fall

Mcdonough, William F.

456

Comparative effects of iron deficiency induced by bleeding and a low-iron diet on the intestinal absorptive interactions of iron, cobalt, manganese, zinc, lead and cadmium.  

PubMed

Dietary iron deficiency enhances the absorption of iron, cobalt, manganese, zinc, cadmium and lead, whereas, iron deficiency due to bleeding increases the absorption of iron, cobalt and perhaps manganese. To determine whether the response to bleeding is qualitatively different from that induced by dietary iron deficiency, metal absorption was studied in mice fed either a high-iron diet (120 ppm Fe) and bled (0.5 ml) or fed a low-iron diet (< 3 ppm Fe). Iron absorption from an intragastric dose was increased by the loss of 0.5 ml of blood; smaller losses of blood had no effect. Also, iron absorption was increased more by dietary iron deficiency than by bleeding. In perfusion experiments, bleeding increased the duodenal absorption of only iron and cobalt, whereas dietary iron deficiency enhanced the absorption of all the metals except cadmium. The patterns of absorptive inhibition of the metals by each other were similar in bled mice and in mice with dietary iron deficiency except that interactions among metals with lower affinities for the iron absorption mechanism--manganese, zinc, cadmium and lead--were more obvious in mice fed the low-iron diet. We concluded that bleeding only partially activates the iron absorptive mechanism and that the lack of a bleeding effect on the absorption of manganese, zinc, cadmium and lead results from the weaker interactions of these metals, with a partly-activated absorption process. PMID:7411235

Flanagan, P R; Haist, J; Valberg, L S

1980-09-01

457

The effect of serum iron concentration on iron secretion into mouse milk  

PubMed Central

The concentration of iron in mouse milk is approximately 3 times that of the serum. Although there is clear evidence for the presence of the transferrin receptor in the rodent mammary gland, the precise mechanisms of iron transfer into milk are not known. Milk iron was linearly related to the serum iron:transferrin ratio in lactating mice whose serum iron ranged from 8 to 66 ?m. Increasing the iron binding capacity of the milk by 340 ?m by targeting the lactoferrin transgene to the mammary gland did not alter the relation between milk iron and the serum iron:transferrin ratio. The steady-state distribution ratio of 125I-transferrin between plasma and milk was about 0.2, indicating that transcytosed transferrin contributed a maximum of 6% of the milk iron. Fluorescently labelled transferrin incubated with the in situ gland localized mainly near the basal surface of the mammary alveolar cells. These experiments provide evidence that the initial and rate-limiting step in the transfer of iron into milk is binding to a basal transferrin receptor. A theoretical model of the relation between milk and serum iron suggests that the affinity of apotransferrin for the basal recycling system may be higher than observed in many other cell types. PMID:10713971

Zhang, Peifang; Sawicki, Valerie; Lewis, Andy; Hanson, Linda; Monks, Jenifer; Neville, Margaret C

2000-01-01

458

Impact of iron overload and potential benefit from iron chelation in low-risk myelodysplastic syndrome.  

PubMed

Myelodysplastic syndromes (MDSs) are a group of heterogeneous clonal bone marrow disorders characterized by ineffective hematopoiesis, peripheral blood cytopenias, and potential for malignant transformation. Lower/intermediate-risk MDSs are associated with longer survival and high red blood cell (RBC) transfusion requirements resulting in secondary iron overload. Recent data suggest that markers of iron overload portend a relatively poor prognosis, and retrospective analysis demonstrates that iron chelation therapy is associated with prolonged survival in transfusion-dependent MDS patients. New data provide concrete evidence of iron's adverse effects on erythroid precursors in vitro and in vivo. Renewed interest in the iron field was heralded by the discovery of hepcidin, the main serum peptide hormone negative regulator of body iron. Evidence from ?-thalassemia suggests that regulation of hepcidin by erythropoiesis dominates regulation by iron. Because iron overload develops in some MDS patients who do not require RBC transfusions, the suppressive effect of ineffective erythropoiesis on hepcidin may also play a role in iron overload. We anticipate that additional novel tools for measuring iron overload and a molecular-mechanism-driven description of MDS subtypes will provide a deeper understanding of how iron metabolism and erythropoiesis intersect in MDSs and improve clinical management of this patient population. PMID:24923296

Shenoy, Niraj; Vallumsetla, Nishanth; Rachmilewitz, Eliezer; Verma, Amit; Ginzburg, Yelena

2014-08-01

459

Iron-Sulfur Cluster Synthesis, Iron Homeostasis and Oxidative Stress in Friedreich Ataxia  

PubMed Central

Friedreich ataxia (FRDA) is an autosomal recessive, multi-systemic degenerative disease that results from reduced synthesis of the mitochondrial protein frataxin. Frataxin has been intensely studied since its deficiency was linked to FRDA in 1996. The defining properties of frataxin—(i) the ability to bind iron, (ii) the ability to interact with, and donate iron to, other iron-binding proteins, and (iii) the ability to oligomerize, store iron and control iron redox chemistry—have been extensively characterized with different frataxin orthologues and their interacting protein partners. This very large body of biochemical and structural data [reviewed in (Bencze et al., 2006)] supports equally extensive biological evidence that frataxin is critical for mitochondrial iron metabolism and overall cellular iron homeostasis and antioxidant protection [reviewed in (Wilson, 2006)]. However, the precise biological role of frataxin remains a matter of debate. Here, we review seminal and recent data that strongly link frataxin to the synthesis of iron-sulfur cluster cofactors (ISC), as well as controversial data that nevertheless link frataxin to additional iron-related processes. Finally, we discuss how defects in ISC synthesis could be a major (although likely not unique) contributor to the pathophysiology of FRDA via (i) loss of ISC-dependent enzymes, (ii) mitochondrial and cellular iron dysregulation, and (iii) enhanced iron-mediated oxidative stress. PMID:22917739

Vaubel, Rachael A.; Isaya, Grazia

2012-01-01

460

Iron-Accelerated Neuronal Differentiation of Human Embryonic Stem Cells  

E-print Network

maturation of elevated iron concentration accelerated cellsaccelerated neuronal differentiation from hESCs We examined whether higher iron concentration can accelerate neuronal differentiation and maturation.

Lu, David Tong

2014-01-01

461

Process to Produce Iron Nanoparticle Lunar Dust Simulant Composite  

NASA Technical Reports Server (NTRS)

A document discusses a method for producing nanophase iron lunar dust composite simulant by heating a mixture of carbon black and current lunar simulant types (mixed oxide including iron oxide) at a high temperature to reduce ionic iron into elemental iron. The product is a chemically modified lunar simulant that can be attracted by a magnet, and has a surface layer with an iron concentration that is increased during the reaction. The iron was found to be -iron and Fe3O4 nanoparticles. The simulant produced with this method contains iron nanoparticles not available previously, and they are stable in ambient air. These nanoparticles can be mass-produced simply.

Hung, Ching-cheh; McNatt, Jeremiah

2010-01-01

462

Reconstruction of Gene Networks of Iron Response in Shewanella oneidensis  

SciTech Connect

It is of great interest to study the iron response of the -proteobacterium Shewanella oneidensis since it possesses a high content of iron and is capable of utilizing iron for anaerobic respiration. We report here that the iron response in S. oneidensis is a rapid process. To gain more insights into the bacterial response to iron, temporal gene expression profiles were examined for iron depletion and repletion, resulting in identification of iron-responsive biological pathways in a gene co-expression network. Iron acquisition systems, including genes unique to S. oneidensis, were rapidly and strongly induced by iron depletion, and repressed by iron repletion. Some were required for iron depletion, as exemplified by the mutational analysis of the putative siderophore biosynthesis protein SO3032. Unexpectedly, a number of genes related to anaerobic energy metabolism were repressed by iron depletion and induced by repletion, which might be due to the iron storage potential of their protein products. Other iron-responsive biological pathways include protein degradation, aerobic energy metabolism and protein synthesis. Furthermore, sequence motifs enriched in gene clusters as well as their corresponding DNA-binding proteins (Fur, CRP and RpoH) were identified, resulting in a regulatory network of iron response in S. oneidensis. Together, this work provides an overview of iron response and reveals novel features in S. oneidensis, including Shewanella-specific iron acquisition systems, and suggests the intimate relationship between anaerobic energy metabolism and iron response.

Yang, Yunfeng [ORNL; Harris, Daniel P [ORNL; Luo, Feng [Clemson University; Joachimiak, Marcin [Clemson University; Wu, Liyou [University of Oklahoma; Dehal, Paramvir [Lawrence Berkeley National Laboratory (LBNL); Jacobsen, Janet [Lawrence Berkeley National Laboratory (LBNL); Yang, Zamin Koo [ORNL; Gao, Haichun [University of Oklahoma; Arkin, Adam [Lawrence Berkeley National Laboratory (LBNL); Palumbo, Anthony Vito [ORNL; Zhou, Jizhong [University of Oklahoma

2009-01-01

463

Southern Ocean iron fertilization by baleen whales and Antarctic krill  

E-print Network

Southern Ocean iron fertilization by baleen whales and Antarctic krill Stephen Nicol1,2 , Andrew, iron fertilization, krill, Southern Ocean Correspondence: Stephen Nicol, Australian Antarctic Division

Kudela, Raphael M.

464

Mitochondrial Iron Metabolism and Sideroblastic Anemia  

Microsoft Academic Search

Sideroblastic anemias are a heterogeneous group of disorders, characterized by mitochondrial iron overload in developing red blood cells. The unifying characteristic of all sideroblastic anemias is the ring sideroblast, which is a pathological erythroid precursor containing excessive deposits of non-heme iron in mitochondria with perinuclear distribution creating a ring appearance. Sideroblastic anemias may be hereditary or acquired. Hereditary sideroblastic anemias

Alex D. Sheftel; Des R. Richardson; Josef Prchal; Prem Ponka

2009-01-01

465

Iron Deficiency in Adolescents and Young Adults.  

ERIC Educational Resources Information Center

Reviews the prevalence, natural history, causes, impact on performance, diagnosis, and treatment of iron deficiency in adolescent and young adult athletes. All athletes should be screened and treated. The best diagnosis involves determining serum ferritin and hemoglobin levels. Treatment requires therapeutic doses of oral ferrous iron for several…

Risser, William L.; Risser, Jan M. H.

1990-01-01

466

7, 13571390, 2007 Iron speciation in  

E-print Network

ACPD 7, 1357­1390, 2007 Iron speciation in atmospherically processed aerosols B. J. Majestic et al-ox speciation in atmospherically processed aerosols B. J. Majestic, J. J. Schauer, and M. M. Shafer Correspondence to: J. J. Schauer (jschauer@engr.wisc.edu) 1357 #12;ACPD 7, 1357­1390, 2007 Iron speciation

Boyer, Edmond

467

Hepcidin and Iron Homeostasis during Pregnancy  

PubMed Central

Hepcidin is the master regulator of systemic iron bioavailability in humans. This review examines primary research articles that assessed hepcidin during pregnancy and postpartum and report its relationship to maternal and infant iron status and birth outcomes; areas for future research are also discussed. A systematic search of the databases Medline and Cumulative Index to Nursing and Allied Health returned 16 primary research articles including 10 human and six animal studies. Collectively, the results indicate that hepcidin is lower during pregnancy than in a non-pregnant state, presumably to ensure greater iron bioavailability to the mother and fetus. Pregnant women with undetectable serum hepcidin transferred a greater quantity of maternally ingested iron to their fetus compared to women with detectable hepcidin, indicating that maternal hepcidin in part determines the iron bioavailability to the fetus. However, inflammatory states, including preeclampsia, malaria infection, and obesity were associated with higher hepcidin during pregnancy compared to healthy controls, suggesting that maternal and fetal iron bioavailability could be compromised in such conditions. Future studies should examine the relative contribution of maternal versus fetal hepcidin to the control of placental iron transfer as well as optimizing maternal and fetal iron bioavailability in pregnancies complicated by inflammation. PMID:25093277

Koenig, Mary Dawn; Tussing-Humphreys, Lisa; Day, Jessica; Cadwell, Brooke; Nemeth, Elizabeta

2014-01-01

468

METALLOPROTEINS A complex iron-calcium cofactor  

E-print Network

METALLOPROTEINS A complex iron-calcium cofactor catalyzing phosphotransfer chemistry Shee Chien ions (Fe3+ ), three calcium ions (Ca2+ ), and an oxo group bridging three of the metal ions. NotablyX-phosphate complex de- tected 3.4 T 0.3 atoms of calcium and 1.6 T 0.1 atoms of iron per complex, with no other can

Napp, Nils

469